CA2180435A1 - Coated abrasive containing erodible agglomerates - Google Patents
Coated abrasive containing erodible agglomeratesInfo
- Publication number
- CA2180435A1 CA2180435A1 CA002180435A CA2180435A CA2180435A1 CA 2180435 A1 CA2180435 A1 CA 2180435A1 CA 002180435 A CA002180435 A CA 002180435A CA 2180435 A CA2180435 A CA 2180435A CA 2180435 A1 CA2180435 A1 CA 2180435A1
- Authority
- CA
- Canada
- Prior art keywords
- abrasive grains
- coated
- erodible
- coated abrasive
- abrasive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D11/00—Constructional features of flexible abrasive materials; Special features in the manufacture of such materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
- B24D3/34—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties
- B24D3/342—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties incorporated in the bonding agent
- B24D3/344—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties incorporated in the bonding agent the bonding agent being organic
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K3/00—Materials not provided for elsewhere
- C09K3/14—Anti-slip materials; Abrasives
- C09K3/1436—Composite particles, e.g. coated particles
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Composite Materials (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Polishing Bodies And Polishing Tools (AREA)
Abstract
Coated abrasive article comprising a backing bearing on at least one major surface thereof erodible agglomerates and abrasive grains, wherein the erodible agglomerates consist essentially of a grinding aid and the erodible agglomerates are in the form of rods. The erodible agglomerates can be between or above or between and above the abrasive grains. The coated abrasive article of this invention utilizes a higher level of grinding aid than coated abrasive articles of the prior art.
Description
WO 95/20~(i9 2 1 ~O ~ PCT/US9.1/1~279 ~r)ATEn ARRA':IVE CONTAININt~ ~Rl~DIBLE AG~:T~ RATES
Rackqrolln~ of the Invention l. Field of the Invention This invention relates to coated abrasive products, and, more particularly, to coated abrasive products containing both erodible agglomerates and individual abrasive grains.
10 2. Discussion of the ~Art Coated abrasive products comprise a backing having abrasive grains bonded thereto by one or more binders.
These binders typically comprise a glutinous or resinous adhesive, and, optionally, additional 15 ingredients. Examples of resinous adhesives include phenolic resins, epoxy resins, urethane resins, acrylate resins, and urea-formaldehyde resins.
Examples of typical additives include grinding aids, f illers, wetting agents, surf actants, pigments, 20 coupling agents, and dyes.
It is known that the addition of grinding aids improves the abrading characteristics of coated abrasive products. It is believed that grinding aids 5 igni f icant ly a f f ect the chem i ca l and phys i ca l 25 ~L~ esses of abrading to bring about improved performance. Grinding aids are ~spe~ ly effective in abrading stainless steel and exotic metal alloys. In some instances, a coated abrasive product containin~ a grinding aid in the binder can abrade up to 100% more 30 stainless 6teel than a C~lLL~ OI~1;n~ coated abrasive product in which the binder does not contain a grin~ing aid .
Typically, the binder for a coated abrasive comprises from about 10 to about 50 percent by weight 35 resinous adhesive and from about 50 to about 90 percent by weight grinding aid. If greater amounts of grincling aid are employed, there tends to be an adverse effect on abrading performance, because grinding aids tend to weaken the binder.
WO 9~/20~69 ;~ ~ ~ Q 4 ~ ~ PCT/U~9~ 279 Accordingly, it is desired to provide a means for utili7ing a higher level of grinding ~id in a coated abrasive product without significantly reducing the 6trength of the binder.
rSr of the Invention This invention provides a coated abrasive article comprising a backing bearing on at least one major surface thereof erodible agglomerates and abrasive lO grains, wherein the erodible agglomerates comprise:
(a) a binder and a grinding aid; or (b) a grinding aid.
In one t~hotq~ ntl the erodible agglomerates can be disposed underneath, between, and above the abrasive 15 grains. In another t~rhot~ir-nt, the erodible agglomerates can be tl; cpos~ between the abrasive grains. In another t~mht~ r-ntl the erodible agglomerates can be disposed underneath the abrasive grains. In another t~hotlir-nt, the erodible 20 agglomerates can be disposed above the abrasive grains.
Each of these embodiments also t~n~ ,-Cqt~q variations within its general conf iguration . The erodible agglomerate may contain non-abrasive additives that affect the erodibility of the agglomerate This invention also provides an abrasive article wherein the erodible agglomerates comprise thermoplastic rods and abrasive grains. It is preferred that the thermoplastic rods be made of a halogenated thermoplastic material.
In one embodiment, the halogenated thermoplas~ic rods can be disposed between the abrasive grains.
These halogenated thermoplastic rods function as a grinding aid.
The halogenated thermoplastic rods erode during 35 the abrading process so that fresh grinding aid is introduced to the abrading interface. A preferred material for preparing halogenated thermoplastic rods is poly (vinyl chloride) . Examples of other halogenated thermoplastics suitable f or preparing rods include Wo 95120~69 ~ ~ ~ 9 4 3 5 PcrluS94/1~27 halogenated waxes, polyvinylidene chloride, and polyvinylidene fluoride.
Brief Descri~tion of the Drawinqs FIG. l is a side view of a coated abrasive article of this invention wherein the erodible agglomerates are posPd underneath, between, and above the abrasive grains .
FIG. 2 is a side view of a coated abrasive article lO of this invention wherein the erodible agglomerates are di crose~ above the abrasive grains.
FIG. 3 is a side view of a coated abrasive article of this invention wherein the erodible agglomerates are di s:posPd between the abrasive grains.
FIG. 4 is a side view of a coated abrasive article of this invention wherein the erodible agglomerates are disposed below the abrasive grains.
FIG. 5 is a side view of a coated abrasive article of this invention wherein the erodible agglomerates. are 20 dl ~=po~Pd between abrasive grains that are multi-grain granules .
FIG. 6 is a side view of a coated abrasive ar~icle of this invention wherein the erodible agglomerates are d; ~:pnsPd above the abrasive grains.
FIG. 7 is a side view of a coated abrasive article of this invention wherein the erodible agglomerates are d~ s:posPd underneath, between, and above the abrasive grains .
FIG. 8 is a side view of a coated abrasive article 30 of this invention wherein the erodible agglomerates are in the f orm of rods and are disposed between the abrasive grains.
Detailed Descri~tion As used herein, the term "abrasive grains"
includes both individual abrasive grains and multi-grain granules comprising a plurality of abrasive grains .
Rackqrolln~ of the Invention l. Field of the Invention This invention relates to coated abrasive products, and, more particularly, to coated abrasive products containing both erodible agglomerates and individual abrasive grains.
10 2. Discussion of the ~Art Coated abrasive products comprise a backing having abrasive grains bonded thereto by one or more binders.
These binders typically comprise a glutinous or resinous adhesive, and, optionally, additional 15 ingredients. Examples of resinous adhesives include phenolic resins, epoxy resins, urethane resins, acrylate resins, and urea-formaldehyde resins.
Examples of typical additives include grinding aids, f illers, wetting agents, surf actants, pigments, 20 coupling agents, and dyes.
It is known that the addition of grinding aids improves the abrading characteristics of coated abrasive products. It is believed that grinding aids 5 igni f icant ly a f f ect the chem i ca l and phys i ca l 25 ~L~ esses of abrading to bring about improved performance. Grinding aids are ~spe~ ly effective in abrading stainless steel and exotic metal alloys. In some instances, a coated abrasive product containin~ a grinding aid in the binder can abrade up to 100% more 30 stainless 6teel than a C~lLL~ OI~1;n~ coated abrasive product in which the binder does not contain a grin~ing aid .
Typically, the binder for a coated abrasive comprises from about 10 to about 50 percent by weight 35 resinous adhesive and from about 50 to about 90 percent by weight grinding aid. If greater amounts of grincling aid are employed, there tends to be an adverse effect on abrading performance, because grinding aids tend to weaken the binder.
WO 9~/20~69 ;~ ~ ~ Q 4 ~ ~ PCT/U~9~ 279 Accordingly, it is desired to provide a means for utili7ing a higher level of grinding ~id in a coated abrasive product without significantly reducing the 6trength of the binder.
rSr of the Invention This invention provides a coated abrasive article comprising a backing bearing on at least one major surface thereof erodible agglomerates and abrasive lO grains, wherein the erodible agglomerates comprise:
(a) a binder and a grinding aid; or (b) a grinding aid.
In one t~hotq~ ntl the erodible agglomerates can be disposed underneath, between, and above the abrasive 15 grains. In another t~rhot~ir-nt, the erodible agglomerates can be tl; cpos~ between the abrasive grains. In another t~mht~ r-ntl the erodible agglomerates can be disposed underneath the abrasive grains. In another t~hotlir-nt, the erodible 20 agglomerates can be disposed above the abrasive grains.
Each of these embodiments also t~n~ ,-Cqt~q variations within its general conf iguration . The erodible agglomerate may contain non-abrasive additives that affect the erodibility of the agglomerate This invention also provides an abrasive article wherein the erodible agglomerates comprise thermoplastic rods and abrasive grains. It is preferred that the thermoplastic rods be made of a halogenated thermoplastic material.
In one embodiment, the halogenated thermoplas~ic rods can be disposed between the abrasive grains.
These halogenated thermoplastic rods function as a grinding aid.
The halogenated thermoplastic rods erode during 35 the abrading process so that fresh grinding aid is introduced to the abrading interface. A preferred material for preparing halogenated thermoplastic rods is poly (vinyl chloride) . Examples of other halogenated thermoplastics suitable f or preparing rods include Wo 95120~69 ~ ~ ~ 9 4 3 5 PcrluS94/1~27 halogenated waxes, polyvinylidene chloride, and polyvinylidene fluoride.
Brief Descri~tion of the Drawinqs FIG. l is a side view of a coated abrasive article of this invention wherein the erodible agglomerates are posPd underneath, between, and above the abrasive grains .
FIG. 2 is a side view of a coated abrasive article lO of this invention wherein the erodible agglomerates are di crose~ above the abrasive grains.
FIG. 3 is a side view of a coated abrasive article of this invention wherein the erodible agglomerates are di s:posPd between the abrasive grains.
FIG. 4 is a side view of a coated abrasive article of this invention wherein the erodible agglomerates are disposed below the abrasive grains.
FIG. 5 is a side view of a coated abrasive article of this invention wherein the erodible agglomerates. are 20 dl ~=po~Pd between abrasive grains that are multi-grain granules .
FIG. 6 is a side view of a coated abrasive ar~icle of this invention wherein the erodible agglomerates are d; ~:pnsPd above the abrasive grains.
FIG. 7 is a side view of a coated abrasive article of this invention wherein the erodible agglomerates are d~ s:posPd underneath, between, and above the abrasive grains .
FIG. 8 is a side view of a coated abrasive article 30 of this invention wherein the erodible agglomerates are in the f orm of rods and are disposed between the abrasive grains.
Detailed Descri~tion As used herein, the term "abrasive grains"
includes both individual abrasive grains and multi-grain granules comprising a plurality of abrasive grains .
2 t ~35 WO 9S/20~G9 PCTN~9V1.~2i9 Referring to FIG. 1, coated abrasive article 10 comprises a backing 12, a binder 14 adhered to at least one major surface of backing 12, a multiplicity of abrasive grains 16, a multiplicity of erodible 5 agglomerates 18, and a binder 20. Binder 14 secures abrasive grains 16 and erodible agglomerates 18 to backing 12. Binder 20 also secures abrasive grains 16 and erodible agglomerates 18 to backing 12. Binder 14 will hereafter be referred to as the make coat. Binder 10 20 will hereafter be referred to as the size coat.
Backing 12 can be made of any material that is compatible with the material of binder 14 and that exhibits sufficient integrity for the expected abrading process. Examples of materials suitable for backing 12 15 include fibrous sheets, polymeric sheets, paper, cloth, n~ .JV~n sheets, treated versions of these materials, and combinations of these materials.
Binder 14 typically comprises a resinous or glutinous adhesive, and, in many cases, can optionally 20 include other materials. Examples of resinous adhesiyes suitable for this invention include phenolic resins, urea-formaldehyde resins, urethane resins, acrylate resins, aminoplast resins, epoxy resins, and combinations thereof. Optional other materials that 25 can be used in the binder include grinding aids, fillers, wetting agents, coupling agents, surfactants, dyes, and pigments.
In many abrasive articles, the binder includes a particulate filler. Typically, the binder will 30 comprise between 40 to 70 percent by weight particulate filler. The addition of the filler either increases the to~l~hnl~sc and hardness of the binder or reduces the cost of the finished article, e.g., by decreasing the amount of binder required, or both . The f iller is 35 typically an inorganic particulate material, generally having a particle size less than about 40 micrometers.
Examples of common fillers in the abrasive industry include calcium carbonate, calcium oxide, calcium 2 1`80~35 metasilicate, alumina trihydrate, silica, kaolin, quartz, and glass.
There exists a subclass of fillers, rQferred to as grinding aids, cutting aids, or generically as "active S f iller" . An active f iller is typically a particulate material the addition of which to the binder has a significant affect on the chemical and physical processes of abrading which leads to; ~ ed perf ormance .
Abrasive grains 16 suitable for this invention typically have a hardness of at least about 7 on the ~5ohs' scale. Preferably, the abrasive grains of the invention have a hardness of from about 9 to about 10 on the 21ohs ' scale . Examples of such abrasive grains 15 include diamond, cubic boron nitride, boron carbide, alumina zirconia, tungsten carbide, silicon carbide, fused aluminum oxide, heat-treated aluminum oxide, silicon nitride coated silicon carbide, ceramic aluminum oxide, garnet, and mixtures thereof. The 20 abrasive grains preferred for this invention are ceramic aluminum oxide and alumina zirconia. Examples of multi-grain granules that are suitable for use in this invention are described in U. s . Patent Nos.
Reissue 29,808; 4,311,489; 4,652,275; and 4,799,939, 25 incorporated herein by reference.
The erodible agglomerates of this invention can be provided in one of two forms. In one form, the erodible agglomerate can consist essentially of a binder and a grinding aid. In another form, the 33 erodible agglomerate can consist essentially of a grinding aid. In either form, the erodible agglomerate may contain other additives that do not adversely affect the erodibility of the agglomerate. The agglomerate cannot contain abrasive particles, i.e., 35 particles having a Moh hardness in excess of 7, because such particles adversely affect the action of the grinding aid. Erodible agglomerates are typically formed to a desired shape, e.g., spherical, cylindrical, irregularly shaped.
~S ~ ~ n~
_ _ _ _ _ _ 2~Q4~
W~ 95/20~9 PCr/uss~ J279 When the erodible agglomerates are in the f orm of rods, it is preferred that the rods be positioned between the abrasive grains, as illustrated in Figure 8. It is also preferred that each of the rods be S oriented so that the axis thereof is substantially perpPn~;c~ r to the backing, as illustrated in Figure 8. However, each of the rods need not be oriented 50 that the axis is perpendicular to the backing.
The ratio of the maximum dimension of the erodible 10 thermoplastic rods to the maximum dimension of the abrasive grains can range from about 2 . 5 :1. 0 to about 0 . 5 :1. 0 . The ratio of the volume of the rods to the volume of the abrasive grains in the abrasive article can range from about 5:95 to about 95:5, preferably 15 from about 30:70 to about 70:30. It is preferred that the erodible thermoplastic rods have about the same maximum dimension as that of the abrasive grains.
Also, it is preferred that the area of the backing occupied by each rod be kept as low as possible. The 20 aspect ratio of the rod can range from about 0.5:1.0 to about 10.0:1.0, preferably from about 0.5:1.0 to about 5.0:1Ø
The cross-sectional shape of the thermoplastic rods, when made by extrusion or molding, can be any 25 shape fea6ible by an extrusion or molding process.
Circular , triangular , rectangular , e . g ., square , elliptical, hexagonal, pentagonal, octagonal, and oval cross-sectional shapes are considered normal, but numerous other shapes, e. g . stars, are within the scope 30 of this invention. When the cross-section of the rod is circular, the rod is usually referred to as a cylindrical rod.
The rods can be drop coated or electrostatically coated into the make coat. The rods may also contain 35 non-thermoplastic grinding aids or optional additives or both. Such additives include filIers, coupling agents, dyes, pigments, antistatic agents, wetting agents, and the like. The thermoplastic rod may optionally contain a binder. The rod may optionally 2 1 ~ 5 wo 95/20469 PCr/US9~/1427g have a surface coating to modify some physical property of the rod . P~lternatively, the surf ace of the rod may be textured to increase the surface area to promote adhesion .
The use of halogenated thermoplastic rods makes il:
pos6ible to provide higher levels of grinding aid to a coated abrasive article than is possible with conventional supersize coats. Therefore, the overall cost of the article can be lower than that of articles 10 employing conventional supersize coats.
Because the halogenated thermoplastic rods are erodible, they can provide a continual supply of fresh grinding aid during the life of the coated abrasive article. This is believed to be an ~ ~.v. t_ over 15 using only a thin layer of grinding aid on the surface of the coated abrasive article. Patents that refer to polyvinyl chloride as a chemically active grinding aid include U.S. Patent Nos. 2,272,873, 2,327,846, 2,421,623, and 3,256,076. It is preferred that the 20 concentration of chlorine in the poly(vinyl chloride) range from 50 to 75% by weight. Higher levels of chlorine can be used so long as the amount of ~IydL~y~
chloride gas produced during grinding does not produce adverse conditions.
When the erodible agglomerate includes a binder, the binder of the erodible agglomerate can be inorganic or organic. Examples of inorganic binders include cements, calcium oxide, clay, silica, magnesium oxide, aluminum oxide, etc. Examples of organic binders 30 include waxes, phenolic resins, urea-formaldehyde resins, urethane resins, acrylate resins, aminoplast resins, glue, polyvinyl alcohol, epoxy resins, and combinations thereof . The pref erred organic binder is a wax having a high melting temperature. It is 35 believed that the wax binder provides a lubricating effect during abrading, thereby increasing the abrading ability of the coated abrasive article. Examples of waxes suitable for the erodible agglomerates include carnauba wax and paraf f in wax.
21 8043~
Wo 95/201G9 pcrlus94ll4279 As used herein a "grinding aid" is a particulate material that has a significant effect on the chemical and physical processes of abrading, thereby resulting in improved performance of a coated abrasive article.
5 It is believed that the grinding aid will (l) decrease the friction between the abrasive grains and the workpiece being abraded, (2) prevent the abrasive grain ~rom "capping", i . e. prevent metal particles from ~e~ welded to the tops of the abrasive grains, (3) l0 decrease the interface temperature between the abrasive grains and the workpiece, or (4) decrease the grinding force required. In general, the addition of a grinding aid increases the useful life of a coated abrasive.
Examples of classes of grinding aids, which include a 15 wide variety of dif f erent inorganic and organic materials, include waxes, organic halides, halide salts, and metals and their alloys. Organic halides, such as poly(vinyl chloride), will typically break down during abrading and release a halogen acid or a gaseous 20 halide ~_vl~ly~lulld. Examples of organic halides include halogenated waxes, for example, chlorinated waxes, such as, tetrachloronaphthalene and pentachloronaphthalene, polyvinylidene chloride, polyvinylidene fluoride, poly (vinyl chloride), and chlorinated poly (vinyl 25 chloride). Chlorinated waxes can also be considered to be grinding aids. Examples of halide salts include sodium chloride, potassium cryolite, cryolite, ammonium cryolite, potassium tetrafluoroborate, sodium tetrafluoroborate, silicon fluorides, potassium 30 chloride, magnesium chloride. Examples of metals include tin, lead, bismuth, cobalt, antimony, cadmium, iron, and titanium. Other grinding aids include sulfur, organic sulfur compounds, metallic sulfides, and graphite. It is also within the scope of this 35 invention to use a combination of different grinding aids. In some instances, combining grinding aids may produce a synergistic effect. ~ The preferred grinding aids of this invention are cryolite, potassium tetrafluoroborate, and polyvinyl chloride. Grinding 2.~
WO 95/20~9 PCT/US9~114279 aids are considered to be non-abrasive, i. e ., the Moh hardness of grinding aids is less than 7.
Technical literature explains that the grinding o~
metal by abrasive articles produces freshly formed, - 5 hot, and uncontaminated metal surfaces. If the newly formed, uncontaminated metal surface isn't rapidly "contaminated", metal will transfer and adhere to the abrasive particle surface (s) causing "capping" which decreases grinding perf ormance . The purpose and lO function of grinding aids is to prevent capping by rapidly contaminating the freshly formed metal surface Grinding aids are normally incorporated into the bond resin(s) of the abrasive article. Grinding aids (active fillers) can be classified as physically active 15 or chemically active. Cryolite, sodium chloride, and potassium tetrafluoroborate are known physically active grinding aids that melt between 500 and l,000C which can form thin films on freshly formed metal.
Chemically active grinding aids include iron pyrite, 20 polyvinyl chloride, and polyvinylidene chloride which 1~ rsc when heated forming chemicals that rapidly react with the freshly formed metal surface.
Interestingly, iron pyrite Pnh~nr~c the abrasive grinding performance on stainless steel more so than 25 cryolite. Cryolite can have a solvent action on ninl1m oxide abrasive grains reducing its grinding effectiveness on stainless steel.
The size of the grinding aid in the erodible agglomerate that contain a binder can range from about 30 0.5 micrometer to about 500 micrometers, preferably from about lO micrometers to about 150 micrometers.
The percentage of grinding aid in the erodible agglomerate that contains a binder can vary from 5 to 90% by weight, preferably from about 60 to 90% by 35 weight, of the erodible agglomerate. The 1 in~r of this erodible agglomerate will comprise binder and other optional additives. The erodible agglomerate should contain at least about 1% by weight binder, preferably about 5 to lO9~ by weight binder.
WO 95/20-169 2 ~ 8 ~ PCT/US9~ 279 The erodible agglomerate that does not contain a binder can consist essentially of a grinding aid. The grinding aid can be selected from those materials described previously. The grinding aid may contain 5 trace amounts of impurities. In this particular form of erodible agglomerate, the binder is absent and the grinding aid has a particle size sufficiently large-to f orm an erodible agglomerate . In the agglomerate that does not contain a binder, the preferred grinding aids lO are polyvinyl chloride and potassium tetrafluoroborate.
Erodible agglomerates that contain a binder can contain other additives such as dyes, pigments, wetting agent6, curing agents, surf actants, and organic fillers. Representative examples of organic fillers 15 include wood pulp and wood f lour . Erodible agglomerates containing grinding aids may additionally contain an inorganic particulate material that is not cnncicl~ed to be a grinding aid, such as, for example, glass bubbles. ~lowever, as stated previously, the 20 erodible agglomerates cannot contain abrasive particulate material, as this material adversely affects the activity pf the grinding aid.
Whether or not the erodible agglomerates contain a binder, erodible agglomerates suitable for this 25 invention must be erodible, i.e., during the abrading process, the agglomerate must break down or wear away to expose a fresh new surface. Erosion of the erodible ~gglomerate continuously introduces unused grinding aid to the abrading interface to bring about improved 3 0 perf ormance .
The ratio of the size of the erodible agglomerate to the size of the abrasive grains can range from about 2.5:1 to about 0.5:1. It is preferred that the erodible agglomerate be about the same size as the 35 abrasive grains. This range applies to erodible agglomerates whether or not they contain a binder.
Erodible agglomerates that contain a binder can be made according to the following procedure. The non-Abrasive, inorganic particulate material or the 2 1 ~
WO 95/20469 PcrluS9~114279 grinding aid and the glutinous adhesive or resinous adhesive are introduced into a mixing vessel. The resulting mixture is stirred until it is homogeneous.
It i5 preferred that there be sufficient liquid in the - 5 mixture that the resulting mixture is neither excessively stiff nor excessively runny. Most glutinous adhesives and resins contain sufficient liquid to permit adequate mixing. After the mixing step is complete, the mixture is caused to solidify, lO preferably by means of heat or radiation energy.
Solidif ication results from either the removal of liquid from the mixture or the polymerization of the resinous adhesive. After the mixture is solidified, it is crushed to form agglomerates, which are then graded 15 to the desired size. Devices suitable for this step include conventional jaw crushers and roll crushers.
If the binder of the agglomerate is a wax, it is preferred that the erodible agglomerate be made according to the following ~JLOCedULe. The wax is 20 heated to just above its melting t~eLC~ULe. Then the heated wax and the non-abrasive, inorganic particulate material or the grinding aid are introduced into a heated screw type extruder, and the resulting mixture is stirred until it is homogeneous. Next, the mixture 25 is run through the die of the extruder, and the resulting extrudate is cooled and crushed to form agglomerates, which are then graded to the desired size .
The crushing and grading procedures described 30 above frequently provide agglomerates of an undesirable size. The improperly-sized agglomerates can either be recycled, e.g., by being added to a new dispersion, or discarded .
Erodible agglomerates that contain a grinding aid 35 but no binder can be made by dispersing the grinding aid in an d~,yrupLiate medium, e.g., water, organic solvent, drying the dispersion to form a cake, crushing the cake, and grading the particles to the desired size . -ll-Wo95/20JG9 2 ~ g04~5 pcrlus9~ 279 The coated abrasive article of FIG. 1 can be made by f irst thoroughly mixing the binder f or preparing make coat 14, abrasive grains 16, and erodible agglomerates 18, then applying the mixture to backing 5 12, and at least partially curing the binder to form make c02t 14. Then, the binder for preparing size coat 20 is applied over make coat 14, abrasive grains 16, and erodible agglomerates 18, and make coat 14 and size coat 20 are completely cured.
In FIG. 2, coated abrasive article 30 comprises a backing 32, a make coat 34 overlying at least one major surface of backing 32, a multiplicity of abrasive grains 36 supported by backing 32 and adhered thereto by make coat 34, a size coat 38 overlying abrasive 15 grains 36 and make coat 34, and a multiplicity of erodible agglomerates 40 adhered to size coat 38.
Materials suitable for backing 32, erodible agglomerates 40, and abrasive grains 36 can be the same as those used in the coated abrasive article of FIG. 1.
20 Make coat 34 and size coat 38 can be made of the same material or of different materials, and these materials can be the same as those used for the binders de6cribed in the coated abrasive article of FIG. 1.
The coated abrasive article of FIG. 2 can be made 25 according to the following prPcedure. Make coat 34 is ~pplied to backing 32; then a multiplicity of abrasive grain6 36 are electrostatically coated onto make coat 34. Make coat 34 is precured. Next, size coat 38 is applied over abrasive grains 36; then a multiplicity of 30 erodible agglomerates 40 are drop coated onto size coat 38. Both make coat 34 and size coat 38 are more completely cured.
In FIG. 3, coated abrasive article 50 comprises a backing 52, a make coat 54 overlying at least one major 35 surface of backing 52, a multiplicity of abrasive grains 56 and a multiplicity of erodible agglomerates 58 supported by and adhered to backing 52 by make coat 54, and a size coat 60 overlying erodible agglomerates 58 and abrasive grains 56. The materials suitable for Wo 9~/20~69 2 ~ 8 0 ~ 3 5 PCT/US9~/14279 backing 52, erodible agglomerates 58, and abrasive grains 56 can be the same as were described for the coated abrasive article of FIG. 1. Make coat 54 and size coat 60 can be made of the same material or of - 5 aifferent materials, and these materials can be the same as were described f or the binder of the coated abrasive article of FIG. l.
The coated abrasive article of FIG. 3 can be made according to the f ollowing procedure . Erodible lO agglomerates 58 and abrasive grains 56 are combined and mixed thoroughly. Make coat 54 is applied to backing 52; then the mixture of abrasive grains 56 and erodible agglomerates 58 can be drop-coated or electrostatically coated onto make coat 54. Make coat 54 is then 15 precured. Next, size coat 60 is applied over abrasive grains 56, erodible agglomerates 58, and make coat 54, and make coat 54 and size coat 60 are completely cured.
Coated abrasive article 70 of FIG. 4 comprises a backing 72, a make coat 74 overlying at least one major 20 surface of backing 72, a multiplicity of erodible agglomerates 76 supported by and adhered to backing 72 by make coat 74, a multiplicity of abrasive grains 78 overlying erodible agglomerates 76, and a size coat 80 overlying abrasive grains 78. The materials suitable 25 for backing 72, erodible agglomerates 78, and abrasive grains 76 can be the same as were described for the coated abrasive article of FIG. l. Make coat 74 and size coat 80 can be made of the same material or of different materials, and these materials can be the 30 same as were described for the binder of the coated abrasive article of FIG. l.
The coated abrasive article of FIG. 4 can be made according to the following procedure. Make coat 74 is applied to backing 72; then a multiplicity of erodible 35 agglomerates 76 are drop-coated onto make coat 74.
Next, a multiplicity of abrasive grains 78 are electrostatically coated over erodible agglomerates 76.
Make coat 74 is then pre-cured. Next, size coat 80 is W095/20~69 2 ~ 8 Q ~ ~ PCT/US9~114279 applied over abrasive grains 78, and make coat 74 and size coat 80 are completely cured.
In FIG. 5, coated abrasive article 90 comprises a backing 92, a make coat 94 overlying at least one major 5 surface of backing 92, a plurality of erodible agglomerates 96 and a plurality of abrasive grains 98 supported by and adhered to backing 92 by make coat 94, and a size coat 100 overlying erodible agglomerates 96, abrasive grains 98, and make coat 94. The abrasive 10 grains are disposed primarily between the erodible agglomerates. In FIG. 5, however, multi-grain granules are used instead of individual abrasive grains. Such abrasive grains are described in U. S. Patent Nos.
Backing 12 can be made of any material that is compatible with the material of binder 14 and that exhibits sufficient integrity for the expected abrading process. Examples of materials suitable for backing 12 15 include fibrous sheets, polymeric sheets, paper, cloth, n~ .JV~n sheets, treated versions of these materials, and combinations of these materials.
Binder 14 typically comprises a resinous or glutinous adhesive, and, in many cases, can optionally 20 include other materials. Examples of resinous adhesiyes suitable for this invention include phenolic resins, urea-formaldehyde resins, urethane resins, acrylate resins, aminoplast resins, epoxy resins, and combinations thereof. Optional other materials that 25 can be used in the binder include grinding aids, fillers, wetting agents, coupling agents, surfactants, dyes, and pigments.
In many abrasive articles, the binder includes a particulate filler. Typically, the binder will 30 comprise between 40 to 70 percent by weight particulate filler. The addition of the filler either increases the to~l~hnl~sc and hardness of the binder or reduces the cost of the finished article, e.g., by decreasing the amount of binder required, or both . The f iller is 35 typically an inorganic particulate material, generally having a particle size less than about 40 micrometers.
Examples of common fillers in the abrasive industry include calcium carbonate, calcium oxide, calcium 2 1`80~35 metasilicate, alumina trihydrate, silica, kaolin, quartz, and glass.
There exists a subclass of fillers, rQferred to as grinding aids, cutting aids, or generically as "active S f iller" . An active f iller is typically a particulate material the addition of which to the binder has a significant affect on the chemical and physical processes of abrading which leads to; ~ ed perf ormance .
Abrasive grains 16 suitable for this invention typically have a hardness of at least about 7 on the ~5ohs' scale. Preferably, the abrasive grains of the invention have a hardness of from about 9 to about 10 on the 21ohs ' scale . Examples of such abrasive grains 15 include diamond, cubic boron nitride, boron carbide, alumina zirconia, tungsten carbide, silicon carbide, fused aluminum oxide, heat-treated aluminum oxide, silicon nitride coated silicon carbide, ceramic aluminum oxide, garnet, and mixtures thereof. The 20 abrasive grains preferred for this invention are ceramic aluminum oxide and alumina zirconia. Examples of multi-grain granules that are suitable for use in this invention are described in U. s . Patent Nos.
Reissue 29,808; 4,311,489; 4,652,275; and 4,799,939, 25 incorporated herein by reference.
The erodible agglomerates of this invention can be provided in one of two forms. In one form, the erodible agglomerate can consist essentially of a binder and a grinding aid. In another form, the 33 erodible agglomerate can consist essentially of a grinding aid. In either form, the erodible agglomerate may contain other additives that do not adversely affect the erodibility of the agglomerate. The agglomerate cannot contain abrasive particles, i.e., 35 particles having a Moh hardness in excess of 7, because such particles adversely affect the action of the grinding aid. Erodible agglomerates are typically formed to a desired shape, e.g., spherical, cylindrical, irregularly shaped.
~S ~ ~ n~
_ _ _ _ _ _ 2~Q4~
W~ 95/20~9 PCr/uss~ J279 When the erodible agglomerates are in the f orm of rods, it is preferred that the rods be positioned between the abrasive grains, as illustrated in Figure 8. It is also preferred that each of the rods be S oriented so that the axis thereof is substantially perpPn~;c~ r to the backing, as illustrated in Figure 8. However, each of the rods need not be oriented 50 that the axis is perpendicular to the backing.
The ratio of the maximum dimension of the erodible 10 thermoplastic rods to the maximum dimension of the abrasive grains can range from about 2 . 5 :1. 0 to about 0 . 5 :1. 0 . The ratio of the volume of the rods to the volume of the abrasive grains in the abrasive article can range from about 5:95 to about 95:5, preferably 15 from about 30:70 to about 70:30. It is preferred that the erodible thermoplastic rods have about the same maximum dimension as that of the abrasive grains.
Also, it is preferred that the area of the backing occupied by each rod be kept as low as possible. The 20 aspect ratio of the rod can range from about 0.5:1.0 to about 10.0:1.0, preferably from about 0.5:1.0 to about 5.0:1Ø
The cross-sectional shape of the thermoplastic rods, when made by extrusion or molding, can be any 25 shape fea6ible by an extrusion or molding process.
Circular , triangular , rectangular , e . g ., square , elliptical, hexagonal, pentagonal, octagonal, and oval cross-sectional shapes are considered normal, but numerous other shapes, e. g . stars, are within the scope 30 of this invention. When the cross-section of the rod is circular, the rod is usually referred to as a cylindrical rod.
The rods can be drop coated or electrostatically coated into the make coat. The rods may also contain 35 non-thermoplastic grinding aids or optional additives or both. Such additives include filIers, coupling agents, dyes, pigments, antistatic agents, wetting agents, and the like. The thermoplastic rod may optionally contain a binder. The rod may optionally 2 1 ~ 5 wo 95/20469 PCr/US9~/1427g have a surface coating to modify some physical property of the rod . P~lternatively, the surf ace of the rod may be textured to increase the surface area to promote adhesion .
The use of halogenated thermoplastic rods makes il:
pos6ible to provide higher levels of grinding aid to a coated abrasive article than is possible with conventional supersize coats. Therefore, the overall cost of the article can be lower than that of articles 10 employing conventional supersize coats.
Because the halogenated thermoplastic rods are erodible, they can provide a continual supply of fresh grinding aid during the life of the coated abrasive article. This is believed to be an ~ ~.v. t_ over 15 using only a thin layer of grinding aid on the surface of the coated abrasive article. Patents that refer to polyvinyl chloride as a chemically active grinding aid include U.S. Patent Nos. 2,272,873, 2,327,846, 2,421,623, and 3,256,076. It is preferred that the 20 concentration of chlorine in the poly(vinyl chloride) range from 50 to 75% by weight. Higher levels of chlorine can be used so long as the amount of ~IydL~y~
chloride gas produced during grinding does not produce adverse conditions.
When the erodible agglomerate includes a binder, the binder of the erodible agglomerate can be inorganic or organic. Examples of inorganic binders include cements, calcium oxide, clay, silica, magnesium oxide, aluminum oxide, etc. Examples of organic binders 30 include waxes, phenolic resins, urea-formaldehyde resins, urethane resins, acrylate resins, aminoplast resins, glue, polyvinyl alcohol, epoxy resins, and combinations thereof . The pref erred organic binder is a wax having a high melting temperature. It is 35 believed that the wax binder provides a lubricating effect during abrading, thereby increasing the abrading ability of the coated abrasive article. Examples of waxes suitable for the erodible agglomerates include carnauba wax and paraf f in wax.
21 8043~
Wo 95/201G9 pcrlus94ll4279 As used herein a "grinding aid" is a particulate material that has a significant effect on the chemical and physical processes of abrading, thereby resulting in improved performance of a coated abrasive article.
5 It is believed that the grinding aid will (l) decrease the friction between the abrasive grains and the workpiece being abraded, (2) prevent the abrasive grain ~rom "capping", i . e. prevent metal particles from ~e~ welded to the tops of the abrasive grains, (3) l0 decrease the interface temperature between the abrasive grains and the workpiece, or (4) decrease the grinding force required. In general, the addition of a grinding aid increases the useful life of a coated abrasive.
Examples of classes of grinding aids, which include a 15 wide variety of dif f erent inorganic and organic materials, include waxes, organic halides, halide salts, and metals and their alloys. Organic halides, such as poly(vinyl chloride), will typically break down during abrading and release a halogen acid or a gaseous 20 halide ~_vl~ly~lulld. Examples of organic halides include halogenated waxes, for example, chlorinated waxes, such as, tetrachloronaphthalene and pentachloronaphthalene, polyvinylidene chloride, polyvinylidene fluoride, poly (vinyl chloride), and chlorinated poly (vinyl 25 chloride). Chlorinated waxes can also be considered to be grinding aids. Examples of halide salts include sodium chloride, potassium cryolite, cryolite, ammonium cryolite, potassium tetrafluoroborate, sodium tetrafluoroborate, silicon fluorides, potassium 30 chloride, magnesium chloride. Examples of metals include tin, lead, bismuth, cobalt, antimony, cadmium, iron, and titanium. Other grinding aids include sulfur, organic sulfur compounds, metallic sulfides, and graphite. It is also within the scope of this 35 invention to use a combination of different grinding aids. In some instances, combining grinding aids may produce a synergistic effect. ~ The preferred grinding aids of this invention are cryolite, potassium tetrafluoroborate, and polyvinyl chloride. Grinding 2.~
WO 95/20~9 PCT/US9~114279 aids are considered to be non-abrasive, i. e ., the Moh hardness of grinding aids is less than 7.
Technical literature explains that the grinding o~
metal by abrasive articles produces freshly formed, - 5 hot, and uncontaminated metal surfaces. If the newly formed, uncontaminated metal surface isn't rapidly "contaminated", metal will transfer and adhere to the abrasive particle surface (s) causing "capping" which decreases grinding perf ormance . The purpose and lO function of grinding aids is to prevent capping by rapidly contaminating the freshly formed metal surface Grinding aids are normally incorporated into the bond resin(s) of the abrasive article. Grinding aids (active fillers) can be classified as physically active 15 or chemically active. Cryolite, sodium chloride, and potassium tetrafluoroborate are known physically active grinding aids that melt between 500 and l,000C which can form thin films on freshly formed metal.
Chemically active grinding aids include iron pyrite, 20 polyvinyl chloride, and polyvinylidene chloride which 1~ rsc when heated forming chemicals that rapidly react with the freshly formed metal surface.
Interestingly, iron pyrite Pnh~nr~c the abrasive grinding performance on stainless steel more so than 25 cryolite. Cryolite can have a solvent action on ninl1m oxide abrasive grains reducing its grinding effectiveness on stainless steel.
The size of the grinding aid in the erodible agglomerate that contain a binder can range from about 30 0.5 micrometer to about 500 micrometers, preferably from about lO micrometers to about 150 micrometers.
The percentage of grinding aid in the erodible agglomerate that contains a binder can vary from 5 to 90% by weight, preferably from about 60 to 90% by 35 weight, of the erodible agglomerate. The 1 in~r of this erodible agglomerate will comprise binder and other optional additives. The erodible agglomerate should contain at least about 1% by weight binder, preferably about 5 to lO9~ by weight binder.
WO 95/20-169 2 ~ 8 ~ PCT/US9~ 279 The erodible agglomerate that does not contain a binder can consist essentially of a grinding aid. The grinding aid can be selected from those materials described previously. The grinding aid may contain 5 trace amounts of impurities. In this particular form of erodible agglomerate, the binder is absent and the grinding aid has a particle size sufficiently large-to f orm an erodible agglomerate . In the agglomerate that does not contain a binder, the preferred grinding aids lO are polyvinyl chloride and potassium tetrafluoroborate.
Erodible agglomerates that contain a binder can contain other additives such as dyes, pigments, wetting agent6, curing agents, surf actants, and organic fillers. Representative examples of organic fillers 15 include wood pulp and wood f lour . Erodible agglomerates containing grinding aids may additionally contain an inorganic particulate material that is not cnncicl~ed to be a grinding aid, such as, for example, glass bubbles. ~lowever, as stated previously, the 20 erodible agglomerates cannot contain abrasive particulate material, as this material adversely affects the activity pf the grinding aid.
Whether or not the erodible agglomerates contain a binder, erodible agglomerates suitable for this 25 invention must be erodible, i.e., during the abrading process, the agglomerate must break down or wear away to expose a fresh new surface. Erosion of the erodible ~gglomerate continuously introduces unused grinding aid to the abrading interface to bring about improved 3 0 perf ormance .
The ratio of the size of the erodible agglomerate to the size of the abrasive grains can range from about 2.5:1 to about 0.5:1. It is preferred that the erodible agglomerate be about the same size as the 35 abrasive grains. This range applies to erodible agglomerates whether or not they contain a binder.
Erodible agglomerates that contain a binder can be made according to the following procedure. The non-Abrasive, inorganic particulate material or the 2 1 ~
WO 95/20469 PcrluS9~114279 grinding aid and the glutinous adhesive or resinous adhesive are introduced into a mixing vessel. The resulting mixture is stirred until it is homogeneous.
It i5 preferred that there be sufficient liquid in the - 5 mixture that the resulting mixture is neither excessively stiff nor excessively runny. Most glutinous adhesives and resins contain sufficient liquid to permit adequate mixing. After the mixing step is complete, the mixture is caused to solidify, lO preferably by means of heat or radiation energy.
Solidif ication results from either the removal of liquid from the mixture or the polymerization of the resinous adhesive. After the mixture is solidified, it is crushed to form agglomerates, which are then graded 15 to the desired size. Devices suitable for this step include conventional jaw crushers and roll crushers.
If the binder of the agglomerate is a wax, it is preferred that the erodible agglomerate be made according to the following ~JLOCedULe. The wax is 20 heated to just above its melting t~eLC~ULe. Then the heated wax and the non-abrasive, inorganic particulate material or the grinding aid are introduced into a heated screw type extruder, and the resulting mixture is stirred until it is homogeneous. Next, the mixture 25 is run through the die of the extruder, and the resulting extrudate is cooled and crushed to form agglomerates, which are then graded to the desired size .
The crushing and grading procedures described 30 above frequently provide agglomerates of an undesirable size. The improperly-sized agglomerates can either be recycled, e.g., by being added to a new dispersion, or discarded .
Erodible agglomerates that contain a grinding aid 35 but no binder can be made by dispersing the grinding aid in an d~,yrupLiate medium, e.g., water, organic solvent, drying the dispersion to form a cake, crushing the cake, and grading the particles to the desired size . -ll-Wo95/20JG9 2 ~ g04~5 pcrlus9~ 279 The coated abrasive article of FIG. 1 can be made by f irst thoroughly mixing the binder f or preparing make coat 14, abrasive grains 16, and erodible agglomerates 18, then applying the mixture to backing 5 12, and at least partially curing the binder to form make c02t 14. Then, the binder for preparing size coat 20 is applied over make coat 14, abrasive grains 16, and erodible agglomerates 18, and make coat 14 and size coat 20 are completely cured.
In FIG. 2, coated abrasive article 30 comprises a backing 32, a make coat 34 overlying at least one major surface of backing 32, a multiplicity of abrasive grains 36 supported by backing 32 and adhered thereto by make coat 34, a size coat 38 overlying abrasive 15 grains 36 and make coat 34, and a multiplicity of erodible agglomerates 40 adhered to size coat 38.
Materials suitable for backing 32, erodible agglomerates 40, and abrasive grains 36 can be the same as those used in the coated abrasive article of FIG. 1.
20 Make coat 34 and size coat 38 can be made of the same material or of different materials, and these materials can be the same as those used for the binders de6cribed in the coated abrasive article of FIG. 1.
The coated abrasive article of FIG. 2 can be made 25 according to the following prPcedure. Make coat 34 is ~pplied to backing 32; then a multiplicity of abrasive grain6 36 are electrostatically coated onto make coat 34. Make coat 34 is precured. Next, size coat 38 is applied over abrasive grains 36; then a multiplicity of 30 erodible agglomerates 40 are drop coated onto size coat 38. Both make coat 34 and size coat 38 are more completely cured.
In FIG. 3, coated abrasive article 50 comprises a backing 52, a make coat 54 overlying at least one major 35 surface of backing 52, a multiplicity of abrasive grains 56 and a multiplicity of erodible agglomerates 58 supported by and adhered to backing 52 by make coat 54, and a size coat 60 overlying erodible agglomerates 58 and abrasive grains 56. The materials suitable for Wo 9~/20~69 2 ~ 8 0 ~ 3 5 PCT/US9~/14279 backing 52, erodible agglomerates 58, and abrasive grains 56 can be the same as were described for the coated abrasive article of FIG. 1. Make coat 54 and size coat 60 can be made of the same material or of - 5 aifferent materials, and these materials can be the same as were described f or the binder of the coated abrasive article of FIG. l.
The coated abrasive article of FIG. 3 can be made according to the f ollowing procedure . Erodible lO agglomerates 58 and abrasive grains 56 are combined and mixed thoroughly. Make coat 54 is applied to backing 52; then the mixture of abrasive grains 56 and erodible agglomerates 58 can be drop-coated or electrostatically coated onto make coat 54. Make coat 54 is then 15 precured. Next, size coat 60 is applied over abrasive grains 56, erodible agglomerates 58, and make coat 54, and make coat 54 and size coat 60 are completely cured.
Coated abrasive article 70 of FIG. 4 comprises a backing 72, a make coat 74 overlying at least one major 20 surface of backing 72, a multiplicity of erodible agglomerates 76 supported by and adhered to backing 72 by make coat 74, a multiplicity of abrasive grains 78 overlying erodible agglomerates 76, and a size coat 80 overlying abrasive grains 78. The materials suitable 25 for backing 72, erodible agglomerates 78, and abrasive grains 76 can be the same as were described for the coated abrasive article of FIG. l. Make coat 74 and size coat 80 can be made of the same material or of different materials, and these materials can be the 30 same as were described for the binder of the coated abrasive article of FIG. l.
The coated abrasive article of FIG. 4 can be made according to the following procedure. Make coat 74 is applied to backing 72; then a multiplicity of erodible 35 agglomerates 76 are drop-coated onto make coat 74.
Next, a multiplicity of abrasive grains 78 are electrostatically coated over erodible agglomerates 76.
Make coat 74 is then pre-cured. Next, size coat 80 is W095/20~69 2 ~ 8 Q ~ ~ PCT/US9~114279 applied over abrasive grains 78, and make coat 74 and size coat 80 are completely cured.
In FIG. 5, coated abrasive article 90 comprises a backing 92, a make coat 94 overlying at least one major 5 surface of backing 92, a plurality of erodible agglomerates 96 and a plurality of abrasive grains 98 supported by and adhered to backing 92 by make coat 94, and a size coat 100 overlying erodible agglomerates 96, abrasive grains 98, and make coat 94. The abrasive 10 grains are disposed primarily between the erodible agglomerates. In FIG. 5, however, multi-grain granules are used instead of individual abrasive grains. Such abrasive grains are described in U. S. Patent Nos.
4,652,275 and 4,799,939, incorporated herein by 15 reference. The materials suitable for backing 92 and erodible agglomerates 96 can be the same as were described for the coated abrasive article of FIG. 1.
Nake coat 94 and size coat 100 can be made of the same material or of different materials, and these materials 20 can be the same as were described for the binder of the coated abrasive article of FIG. 1.
The coated abrasive article of FIG. 5 can be made according to the following procedure. Erodible agglomerates 96 and abrasive grains 98 are combined and 25 mixed thoroughly. Make coat 94 is applied to backing 92; then the mixture of abrasive grains 98 and erodible agglomerates 96 is drop-coated onto make coat 94. Nake coat 94 is then precured. Next, size coat 100 is applied over abrasive grains 98, erodible agglomerates 30 96, and make coat 94, and make coat 94 and size coat 100 are completely cured.
In FIG. 6, coated abrasive article 110 comprises a backing 112, a make coat 114 overlying backing 112, a plurality of abrasive grains 116 supported by and 35 adhered to backing 112 by make coat 114, a plurality of erodible agglomerates 118 overlying abrasive grains 116, and a size coat 120 overlying abrasive grains 116, erodible agglomerates 118, and make coat 114. Most of abrasive grains 116 are disposed underneath erodible 2 ~ S0435 WO 9S/20~69 PCllUS94/1-~279 agglomerates 118. The materials suitable for backing 112, erodible agglomerate~ 118, and abrasive grains 116 can be the same as were described for the coated abrasive article of EIG. 1. Make coat 114 and size 5 coat 120 can be made of the same material or of different materials, and these materials can be the same as were described for the binder of the coated abra6ive article of FIG. 1.
The coated abrasive article of FIG. 6 can be made 10 according to the following procedure. Make coat 114 i5 applied to backing 112; then a multiplicity of abrasive grains 116 are electrostatically coated onto make coat 114. Next, a multiplicity of erodible agglomerates 11 are dLU~ ~.oated over abrasive grains 116. Make coat 15 114 is then precured. Next, size coat 120 is applied over abrasive grains 116, and make coat 114 and size coat 120 are completely cured.
In FIG. 7, coated abrasive article 130 is a lapping film comprising a backing 132 bearing on one 20 major surface thereof a layer 134 comprising abrasive grains 136 and erodible agglomerates 13-3 uniformly dispersed in a binder 140. Backing 132, binder 140, abrasive grains 136, and erodible agglomerates 138 can be of the same materials as those used in the coated 25 abrasive article of Example 1.
The coated abrasive article of FIG. 7, can be made according to the following procedure. Erodible agglomerates 138, abrasive grains 136, and binder 140 are thoroughly mixed. The resulting mixture is applied 30 to backing 132 and then cured.
In FIG. 8, coated abrasive article 150 comprises a backing lS2, a make coat 154 overlying at least one major surface of backing 152, a multiplicity of erodible agglomerates in the form of rods 158 supported 35 by and adhered to backing 152 by make coat 154, and a size coat 160 overlying erodible agglomerates 158 and abrasive grains 156. The materials suitable for backing 152, erodible agglomerates 158, and abrasive grains 156 can be the same as were described for the WO 9Sl20~69 ~ t ~ PCTIUS94/14279 coated abrasive article of FIG. 1. Make coat 154 and size coat 160 can be made of the same material or of different materials, and these materials can be the same as were described for the binder of the coated 5 abrasive article of FIG. 1. ~
The coated abrasive article of FIG. 8 can be made according to the following procedure. Erodible agglomerates 158 and abrasive grains 156 are combined and mixed thoroughly. Make coat 154 is applied to 10 backing 152; then the mixture of abrasive grains 156 and erodible agglomerates 158 can be drop-coated or electrostatically coated onto make coat 154. Make coat 154 is then precured. Next, size coat 160 is applied over abrasive grains 156, erodible agglomerates 158, 15 and make coat 154, and make coat 154 and size coat 160 are further cured.
In each of the ~mhQA i r ts, the volume of erodible agglomerates to the volume of abrasive grains can range from about 0.08:1 to about 1.75:1, preferably from 2 0 about 0 . 5: 1 to about 1: 1.
The following non-limiting examples will further illustrate the invention. All of the percentages are based upon weight, unless indicated otherwise.
Pre~aration of ~rQdible Aaqlomerates pre~aration A
Paraffin wax was dissolved in warm methylene dichloride (CH2Cl2) to form a 10% solution. While the 30 solution was still warm, it was added to a warmed plastic mill containing alumina milling media. Next, the grinding aid was added to the mill, and the resulting mixture was milled for several hours, after which time the milling media was removed. The 35 resulting slurry was dried for several days at 40C to form a cake. The cake was then broken up into small clumps by passing it through a 14 mesh sieve. The erodible agglomerates were then screened such that the average particle size thereof was -24 +48. The ~ wo 95n~G9 2 ~ 3 5 PCTIUS9~ 279 resulting erodible agglomerates consisted of 10% by weight para~fin wax and 90% by weight grinding aid.
Preparation B
Paraffin wax was heated to 90C, and, along with a grinding aid, was introduced into a heated screw type mixer. The two materials were thoroughly mixed; after mixing, the mixture was cooled. After cooling, the mixture was crushed and screened such that the average 10 particle size thereof was -24 +48.
Preparation C
Preparation C was identical to Preparation B, except that carnauba wax was employed and the wax was heated to 100 to 110C.
PreParation of Coated Abrasive Discs PreParation P
First, gra~e 50 abrasive grains were blended with . erodible agglomerates. Second, a 0.76 mm thick vulcanized fibre backing having a 2.2 cm ~ r center hole wa6 coated with a conventional calcium carbonate filled resole phenolic resin (839~ by weight 25 solids) to form a make coat. The wet coating weight was approximately 270 g/m2. Third, the mixture of abrasive grains and erodible agglomerates were electrostatically coated onto the make coat. The weight of the abrasive grains was approximately 480 30 g/m2. Fourth, the abrasive article was precured for 150 minutes at 93 C. Then, a conventional calcium carbonate filled resole phenolic resin (83% by weight solids) was applied over the abrasive grains, the erodible agglomerates, and the make coat at an average 35 weight of approximately 280 g/m2. The resulting product was cured for 11 1/2 hours at 93C. After this step, the coated abrasive disc was flexed and tested.
Wo 9~/20JG9 2 ~ ~ Q ~ 3 ~ PCI;~US9.1~1~279 Preparation E
First, a 0.76 mm thick vulcanized fibre backing having a 2 . 2 cm diameter center hole was coated with a conventional calcium carbonate filled resole phenolic 5 resin (839~ by weight solids) to form a make coat.
Second, grade 50 abrasive grains were electrostatically coated onto the make coat at a weight of zpproximately 480 g/*. Third, the resulting article was precured for 150 minutes at 93C. A conventional calcium carbonate 10 filled resole phenolic resin (83% by weight solids) was applied over the abrasive grains and the make coat to form a size coat. Fourth, erodible agglomerates were drop coated onto the uncured size coat. The resulting product was cured for 11 1/2 hours at 93C. After this 15 step, the coated abrasive disc was flexed and tested.
Pre~aration F
The pL oce.lul e of Preparation E was repeated except ~that the weight of the abrasive grains was 20 approximately 600 g/m2.
Pren~ration of ThermoPlastic Rods Pre~aration G
A mixture containing 70% by weight medium 25 molecular weight poly (vinyl chloride) (commercially nvailable from Schuman, Bellevue, Ohio) and 30% by weight diisononyl phthalate plasticizer was extruded into strands of fiber having a circular cross-sectional shape having a diameter of about 500 micrometers.
3 0 These strands of f iber were cut into rods having a length of about 1, 500 micrometers, thereby giving an ~spect ratio (length/width or height/diameter) of about 3.0:1Ø
Procedure I for Testinq the Coa~ed Abrasive Discs A coated abrasive disc was installed on a conventional air grinder. The disc was mounted on a beveled aluminum back up pad and used to grind the face of a 18.4 cm by 2.54 cm 304 stainless steel workpiece.
Wo gs120~69 2 1 ~ 0 4 3 ~ PcrluS9~ 279 The air ~, esaule to the grinder was approximately 6 . l kg/cm2. The portion of the coated abrasive overlying the beveled edge of the back up pad contacted the workpiece at a 6. 8 kg load.
The workpiece was weighed before and after an abrading cycle to determine the amount of cut, i.e. how much stainles6 steel was removed in thirty seconds.
When the coated abrasive disc removed less than lO g over two consecutive cycles, the test was dcemed ended.
lO In Tables I through IV, the coated abrasive performance was stated a5 percent of control , i . e., the total amount of metal removed for the control example was equated to 100% and the amounts of metal removed by 1 he coated abrasive articles of the examples of the 15 invention were measured relative to the control. The results are based upon an average of two discs per example .
Procedure II for Testin~ the Coated Abrasive Piscs A coated abrasive disc having a diameter of 17 . 8 cm, a 2.2 cm diameter center hole, and a thickness of .
0.76 mm was attached to an aluminum support pad, and the assembly was installed on a heavy flat test apparatus. This test involved placing a workpiece in 25 proximity to the periphery of the disc at a prescribed angle and at a prescribed rotational speed for a prescribed time. The workpiece was a 304 stainless steel disc having a diameter of approximately 25.4 cm and a thickness of 0.18 cm. The applied load was 30 maintained at 4 . 0 kg. The coated abrasive disc rotated at 5000 rpm. The endpoint of the test was 20 minutes.
The 304 stainless 6teel disc was weighed at two minute intervals during testing. The weight loss associated with the 304 stainless steel disc corr~cpr~n~ to the 35 amount that the coated abrasive disc cut, and served as a measure of the efficiency of the coated abrasive disc .
21 sa~
WO 95/2~69 PCIIUS9~ 279 ~
les l throuqh 4 and CQntrol F~ lcs A and 13 ~ ~ -The results for these examples are set forth in Table I. The abrasive grain used in these examples was grade 50 fused aluminum oxide. The coated abrasive of 5 Control Example A was made according Preparation D
except that it did not contain any erodible agglomerates. Control Example B was a commercially available fibre disc, Three-M-ite Type C coated abrasive disc, available from Minnesota Mining and lO Manufacturing Company, St. Paul, Minnesota.
21 ~4~
WO 95/20169 PCT/US9~/14279 O o o o o o o N N
O j I Q
O
O ~ I I o ~ ~r co * j ¦ N N N N
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C
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~ o _ r ~.1 ~I N rl ~r WO 9~/20~69 2 ~ ~ ~ 4 3 ~ PCT/US9~ 279 es 5 and 6 and Control ~YI les B thrQu:Th G
The results for these examples are set forth in Table II. The abrasive grain used in these examples was fused aluminum oxide. Control Example B was a 5 commercially available fibre disc, Three-M-ite Type C
coated abrasive disc, available from Minnesota Mining and Manuf acturing Company, St . Paul, Minnesota . The coated abrasive disc of Control Example C was made according to Preparation F, except that it did not 10 contain any erodible agglomerates.
Control ExamPle ~
A coated abrasive disc was prepared according to the following procedure. First, a 0.76 mm thick 15 vulcanized fibre backing having a 2 . 2 cm diameter center hole was coated with a composition consisting of a conventional calcium carbonate filled resole phenolic resin (839; by weight solids) to form a make coat.~ The wet coating weight was approximately 270 g/m2. Second, 20 grade 50 fused aluminum oxide abrasive grains were electrostatically coated onto the make coat at a w~ight of approximately 600 g/m2. Third, the resulting abrasive article was precured for 150 minutes at 93C.
Fourth, a composition consisting of 48% resole phenolic 25 resin and 52% KBF~ was applied over the abrasive grains and the make coat at an average weight of approximately 280 g/m2 to form a size coat. The resulting product was cured for 11 1/2 hours at 93C. After this step, the coated abrasive disc was flexed and tested.
CQnt~ol Examl~le E
The coated abrasive disc for Control Example E was made and tested in the same manner as was that of Control Example C, except that a supersize coat was 35 applied over the size coat. The supersize coat consisted of 48% resole phenolic resin and 529i KBF~ and was coated at a weight of approximat~ly 260 g/m2.
21 ~435 Wo 9S/20~69 PCTtr~lsg4t14279 ContrQl EY~mrl~ F
The coated abrasive disc for Control Example F was made and tested in the same manner as was that of Control Example D, except that KBF~ was replaced with an 5 equal amount by weight of K3AlF6. The weight of the size coat was approximately 236 g/m2.
Control F~nle G
The coated abrasive disc for Control Example G ~ras 10 made and tested in the same manner as was that of Control Example E, except that KBF4 was replaced with an equal amount by weight of K3AlF6. The weight of the supersize coat was a~proximately 2~2 /m~.
WO 9~120 169 ~ ~ 8 ~ ~ ~ 5 PCT/I~S9V1~1279 -o o o o o o o o o ,- ~ o ~ ~1 ,i ~r o o C~ .
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~ r- r _ r 21 8~435 wo 95/204~9 PCT~S94/l~27s ~les 7 and 8 and Control ExamPles H throuah 1.
The coated abrasive aIticles of Example 7 and 8 were prepared according to the procedure described in Preparation F. In Example 7, the erodible agglomerates 5 were made of K13F~. In Example 8, the erodible agglomerates were made of KIAlF6. The abrasive grain used in these examples was grade 50 ceramic aluminum oxide made according to the teachings of U. S . Patent Number 4,314,827. The results for these examples are 10 set forth in Table III.
Control ExamPle H
Control Example ~ was a commercially available fibre disc, Regal coated abrasive disc, available from 15 Ninnesota Mining and Manufacturing Company, St. Paul, Minnesota. This disc contained a size coat that consi6ted o~ 66$ by weight l~a3AlF6, 32$ by weight resole phenolic resin, and 2$ by weight iron oxide pigment.
Control ExamPle I
The coated abrasive disc for Control Example I was made and tested in the same manner as was that of Control Example D, except that the abrasive grain was grade 50 ceramic aluminum oxide. The weight of the 25 size coat was 320 g/m2.
Control ExamPle J
The coated abrasive disc for Control Example J was made and tested in the same manner was that of AS
30 Control Example E, except that the abrasive grain was grade 50 ceramic ~ Tn;n~lTn oxide. The weight of the supersize coat was 232 g/m2.
Control ExamPle K
The coated abrasive disc for Control Example K was made and tested in the same manner as was that of Control Example F, except that the abrasive grain was grade 50 ceramic aluminum oxide. The weight of the size coat was 320 g/m2.
Wo 95/2~469 2 ~ ~ C 4 ~ ~ PCT/US9~114279 Control Exam~le L
The coated abrasive disc for Control Example L was made and tested in the same manner as was that Control }:xample G, except that the abrasive grain was grade 50 5 ceramic aluminum oxide. The weight of the supersize coat was 240 g/m2.
~ WO 9S120469 2 1 8 ~ ~ ~ 5 PCTIUS94111279 rt~ :~
: O ~ ~ , O O ~D
-U
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r WO 9s/20~6g ~ ~ Q 4 3 5 PCT~S9~114279 ExamPles 9 thrDuah 17 These examples demonstrate the use of paraffin and carnauba waxes as binders f or erodible agglomerates .
The abrasive grain used in these examples was grade 50 5 ceramic aluminum oxide.
Control ExamPle M
The coated abrasive for this example was made according to Preparation F, except that the disc did lO not contain any erodible agglomerates.
TI~BLE IV
Weight of Preparation Inorganic erodible 15 Example no. of erodible particulate agglomerate agglomerate material (g/m7) Control M ---- ---- ----9 C CaC0l 120 lO C Na~AlF~ 120 20 12 C NaCl 120 14 C NaCl 120 15 C Na7CO~ 120 16 C Na~SOA 120 25 17 C KCl 120 2 1 804 3~
o ssl20-169 PCT/US9~ 279 Ta 8LE IV ~ Cont inue~
Ratio of binder to particulate material in the Preparation Cut ( % o:~
5 Example no. agglomerate of Disc Control M) Control M ---- ---- 100 930:70 F 135 lO30:70 F 179 1130:70 F 456 10 12 30: 70 F 233 1325: 75 F 258 1425:75 F 254 1525: 75 F 154 1625: 75 F 150 15 17 25:75 F 242 The data in Table IV show that the coated abrasive discs containing the carnauba wax had a higher initial 20 cut than corresponding discs containing paraffin wax.
r les 18 and 19 and Control ExamPles N and o These examples demonstrate the use of clay as a binder f or the erodible agglomerate . The coated 25 abrasive was tested according to the following ~,cedu,~. The coated abrasive was first converted into a 7.6 cm by 335 cm endless belt. The belt was installed on a constant load surface grinder. A pre-weighed, 304 stainless steel workpiece, approximately 30 2.5 cm by 5 cm by 18 cm, was mounted in a holder, positioned vertically, with the 2.5 cm by 18 cm face confronting approximately 36 cm diameter 60A durometer serrated rubber contact wheel with one on one lands over which was entrained the coated abrasive belt. The 35 workpiece was then reciprocated vertically through a 18 cm path at the rate of 20 cycles per minute, while a spring loaded plunger urged the workpiece against the belt with a load of 9 kg as the belt was driven at a rate of about 2050 m/min. After one minute of grinding WO 95/20469 ~ t 8 0 ~ ~ 5 PCT/US9~114Z79 time, the workpiece holder assembly was removed and reweighed, the amount of stock removed calculated by subtracting the weight after grinding from the original weight. A new, pre-weighed workpiece and holder were 5 then mounted on the equipment. The experimental error on this test was +/- 10%. The test was deemed complete in 20 minutes. The test results are set forth in Table V.
Exam~le 18 Erodible agglomerates were made according to the following procedure. Into a blade mixer were charged 9 kg of Peerless #14 clay, 22.5 kg of water, and 3.6 kg of graphite. The charge was thoroughly mixed; then Z7 15 kg of KBF4 was added slowly, and the charge mixed until it was homogeneous. The resulting mixture was then placed into 1.25 cm trays and dried at 80C for approximately 12 hours. The resulting dried mixture was crushed and screened. The crushed, screened 20 agglomerates were heated at 200C overnight. The agglomerates were screened such that the average particle size thereof was -30 +48.
A coated abrasive article was prepared according to the following procedure. A composition containing 25 849~ by weight solids and consisting of 48% resole phenolic resin and 52% calcium carbonate was applied to an X weight cotton backing at a wet weight of 290 g/m2 to f orm a make coat . The erodible agglomerates were drop coated into the make coat at a weight of 105 g/m2.
30 Grade 50 ceramic aluminum oxide was electrostatically coated onto the make coat at a weight of 470 g/m2. The resulting article was precured for 90 minutes at 88C.
A composition containing 83% by weight solids and consisting of resole phenolic resin and calcium 35 carbonate filler was applied over the abrasive grains at a wet weight of 293 g/m2 to form a size coat. The resulting article was precured for 90 minutes at 88C
and then final cured for 10 ~hours at 100C. The product was then f lexed .
~ wo 95l20469 2 1 8 0 ~ 3 5 PCr/US94/14279 r~le 19 The coated abrasive article of Example 19 was ma~e in the same manner as was that of Example 18, except that the abrasive grain was a grade 50 fused alumina.
Control N
The coated abrasive article of Control Example N
was a grade 50 ~llL~,e r~ ite Polycut Resin Bond Cloth Product, commercially available from Minnesota Mining 10 and Manufacturing Company, St. Paul, Minnesota. This product contained a KBF4 grinding aid.
Control 0 The coated abrasive article of Control Example 0 15 was a grade 50 Three-M-ite Resin Bond Cloth Product, commercially available from Minnesota Mining and Manufacturing Company, St. Paul, Minnesota.
TAPLE V
Example no. Cut (9c of Control N) Control N 100 Control 0 67 Exam~les 20 throuah 23 and ComParative Exam~les P
throuqh S
Coated abrasives discs of Examples 20 through 23 30 were made according to the following procedure. A
resole phenolic/acrylic latex adhesive was applied over the abrasive side of a grade 50 coated abrasive fibre disc. The disc was commercially available from Minnesota Mining and Manufacturing Company, St. Paul, 35 Minnesota. Then polyvinyl chloride (PVC) particles (commercially available from the BF Goodrich Company) were drop coated onto this adhesive. For Example 20, the PVC particles had an average size of 120 micrometers, while in the 1~ ;n;n7 examples, the PVC
WO 95120469 2 1 ~ 0 4 3 5 PcrruS9411J279 particles had an average size of 180 micrometers. The resulting coated abrasive disc was heated or three hours at 95C to solidify the adhesive. The disc was then f lexed and tested . The discs of the Comparative 5 Examples did not contain any adhesive or erodible agglomerate. In all of the Comparative Examples, the grit was of grade 50.
The f ibre discs of these examples were tested according to the following procedure. The discs were lO mounted on a beveled aluminum back up pad and used to grind the face of a 2.5 cm by 18 cm 310 stainles6 steel workpiece. The disc was driven at 5,500 rpm with the portion of the disc overlaying the beveled edge of the back up pad contacting the workpiece at 9 . l kg force to 15 generate a disc wear path of about 14 0 cm . Each disc was used to grind a separate workpiece for one minute each until the cut in a one minute time interval was less than four grams. The total cut for the grinding test is set f orth in Table VI .
21 8~5 WO 95/20~69 P~T/US9~ 279 V
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WO95l20J~9 2 t ~ Q ~ 3 ~ PCT/US95/l~279 The data in Table VI show that the addition of the erodible agglomerate grinding aid significantly increases the abrading characteristics of coated abrasive discs.
Control E~Arnle T and Examl~le 24 Coated abrasive discs for Control Example T were prepared according to the following ~l~cc:duLe. A 0.76 mm thick vulcanized fibre backing having a ~ r- ~r of 10 17 . 8 cm and 2 . 2 cm diameter center hole was coated with a conventional calcium carbonate filled resole phenolic resin (75% by weight solids) to form a make coat. The wet coating weight was approximately 164 g/m2. Grade 36 ceramic aluminum oxide abrasive grains were 15 electrostatically coated into the make coat at a weight of approximately 740 g/mZ. The resulting article was "~ UL~d for 150 minutes at a t~ eLaLuL~ of 93C. A
composition consisting of 32% resole phenolic resin (75% by weight solids), 50 . 2% cryolite (trisodium 20 hexafluoroaluminate), 1.5% red iron oxide, 13.8%
methoxy propanol (85% 2-methoxy propanol and 15%
water), and 2.5% water was applied over the abrâsive grains and the make coat at an average weight of approximately 658 g/m2 to form a size coat. The 25 resulting product was cured for 11 1/2 hours at a temperature of 93 C. An aqueous composition consisting of 29 . 2% epoxy resin (a composition containing a diglycidyl ether of bisphenol A epoxy resin coatable from water, the composition containing approximately 30 60% solids and 40% water, and having the trade designation "CrqD 35201", available from Rhone-Poulenc, Inc.), 0.35% 2-ethyl-4-methyl imidazole ("EMI-24", commercially available from Air Products and Chemicals, Inc. ), 53 . 59c KBF4 (98% pure micropulverized, in which 35 95% by weight passes through a 325 mesh screen and 10096 by weight passes through a 200 mesh screen), 14.1%
water, 0 . 75% sodium dioctyl sulfosuccinate dispersion agent ("Aerosol OT", commercially available from Rohm and Haas), and 2.3% red iron oxide was roll coated over ~ wo gs/20469 2 i ~ ~ 4 3 ~ PCT/US94114279 the size coat and then cured at a temperature of 115C
for go minutes to form a supersize coat. After this step, the coated abrasive di6cs were flexed and humidified at 45% relative humidity for one week prior 5 to testing.
Example 24 was made according to the ~LuceduL.3 for making Control Example T, with two major exceptions.
After the abrasive grains had been applied, polyvinyl chloride rods t500~ diameter by 1500~ length) were 10 electrostatically coated into the make coat precursor at a coating weight of 74 g/m2. No supersize coat was applied to the article of Example 24.
Ploce.luLe II was utilized to test the abrasive articles of these examples. Three or four discs of 15 each type were tested and the results set forth in Table VII.
TABLE VII
Example No . Initial cut ( 2 min . ) Total cut (% of control) (96 of control) 20 Control T 100 100 Various modif ications and alterations of this 25 invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein.
Nake coat 94 and size coat 100 can be made of the same material or of different materials, and these materials 20 can be the same as were described for the binder of the coated abrasive article of FIG. 1.
The coated abrasive article of FIG. 5 can be made according to the following procedure. Erodible agglomerates 96 and abrasive grains 98 are combined and 25 mixed thoroughly. Make coat 94 is applied to backing 92; then the mixture of abrasive grains 98 and erodible agglomerates 96 is drop-coated onto make coat 94. Nake coat 94 is then precured. Next, size coat 100 is applied over abrasive grains 98, erodible agglomerates 30 96, and make coat 94, and make coat 94 and size coat 100 are completely cured.
In FIG. 6, coated abrasive article 110 comprises a backing 112, a make coat 114 overlying backing 112, a plurality of abrasive grains 116 supported by and 35 adhered to backing 112 by make coat 114, a plurality of erodible agglomerates 118 overlying abrasive grains 116, and a size coat 120 overlying abrasive grains 116, erodible agglomerates 118, and make coat 114. Most of abrasive grains 116 are disposed underneath erodible 2 ~ S0435 WO 9S/20~69 PCllUS94/1-~279 agglomerates 118. The materials suitable for backing 112, erodible agglomerate~ 118, and abrasive grains 116 can be the same as were described for the coated abrasive article of EIG. 1. Make coat 114 and size 5 coat 120 can be made of the same material or of different materials, and these materials can be the same as were described for the binder of the coated abra6ive article of FIG. 1.
The coated abrasive article of FIG. 6 can be made 10 according to the following procedure. Make coat 114 i5 applied to backing 112; then a multiplicity of abrasive grains 116 are electrostatically coated onto make coat 114. Next, a multiplicity of erodible agglomerates 11 are dLU~ ~.oated over abrasive grains 116. Make coat 15 114 is then precured. Next, size coat 120 is applied over abrasive grains 116, and make coat 114 and size coat 120 are completely cured.
In FIG. 7, coated abrasive article 130 is a lapping film comprising a backing 132 bearing on one 20 major surface thereof a layer 134 comprising abrasive grains 136 and erodible agglomerates 13-3 uniformly dispersed in a binder 140. Backing 132, binder 140, abrasive grains 136, and erodible agglomerates 138 can be of the same materials as those used in the coated 25 abrasive article of Example 1.
The coated abrasive article of FIG. 7, can be made according to the following procedure. Erodible agglomerates 138, abrasive grains 136, and binder 140 are thoroughly mixed. The resulting mixture is applied 30 to backing 132 and then cured.
In FIG. 8, coated abrasive article 150 comprises a backing lS2, a make coat 154 overlying at least one major surface of backing 152, a multiplicity of erodible agglomerates in the form of rods 158 supported 35 by and adhered to backing 152 by make coat 154, and a size coat 160 overlying erodible agglomerates 158 and abrasive grains 156. The materials suitable for backing 152, erodible agglomerates 158, and abrasive grains 156 can be the same as were described for the WO 9Sl20~69 ~ t ~ PCTIUS94/14279 coated abrasive article of FIG. 1. Make coat 154 and size coat 160 can be made of the same material or of different materials, and these materials can be the same as were described for the binder of the coated 5 abrasive article of FIG. 1. ~
The coated abrasive article of FIG. 8 can be made according to the following procedure. Erodible agglomerates 158 and abrasive grains 156 are combined and mixed thoroughly. Make coat 154 is applied to 10 backing 152; then the mixture of abrasive grains 156 and erodible agglomerates 158 can be drop-coated or electrostatically coated onto make coat 154. Make coat 154 is then precured. Next, size coat 160 is applied over abrasive grains 156, erodible agglomerates 158, 15 and make coat 154, and make coat 154 and size coat 160 are further cured.
In each of the ~mhQA i r ts, the volume of erodible agglomerates to the volume of abrasive grains can range from about 0.08:1 to about 1.75:1, preferably from 2 0 about 0 . 5: 1 to about 1: 1.
The following non-limiting examples will further illustrate the invention. All of the percentages are based upon weight, unless indicated otherwise.
Pre~aration of ~rQdible Aaqlomerates pre~aration A
Paraffin wax was dissolved in warm methylene dichloride (CH2Cl2) to form a 10% solution. While the 30 solution was still warm, it was added to a warmed plastic mill containing alumina milling media. Next, the grinding aid was added to the mill, and the resulting mixture was milled for several hours, after which time the milling media was removed. The 35 resulting slurry was dried for several days at 40C to form a cake. The cake was then broken up into small clumps by passing it through a 14 mesh sieve. The erodible agglomerates were then screened such that the average particle size thereof was -24 +48. The ~ wo 95n~G9 2 ~ 3 5 PCTIUS9~ 279 resulting erodible agglomerates consisted of 10% by weight para~fin wax and 90% by weight grinding aid.
Preparation B
Paraffin wax was heated to 90C, and, along with a grinding aid, was introduced into a heated screw type mixer. The two materials were thoroughly mixed; after mixing, the mixture was cooled. After cooling, the mixture was crushed and screened such that the average 10 particle size thereof was -24 +48.
Preparation C
Preparation C was identical to Preparation B, except that carnauba wax was employed and the wax was heated to 100 to 110C.
PreParation of Coated Abrasive Discs PreParation P
First, gra~e 50 abrasive grains were blended with . erodible agglomerates. Second, a 0.76 mm thick vulcanized fibre backing having a 2.2 cm ~ r center hole wa6 coated with a conventional calcium carbonate filled resole phenolic resin (839~ by weight 25 solids) to form a make coat. The wet coating weight was approximately 270 g/m2. Third, the mixture of abrasive grains and erodible agglomerates were electrostatically coated onto the make coat. The weight of the abrasive grains was approximately 480 30 g/m2. Fourth, the abrasive article was precured for 150 minutes at 93 C. Then, a conventional calcium carbonate filled resole phenolic resin (83% by weight solids) was applied over the abrasive grains, the erodible agglomerates, and the make coat at an average 35 weight of approximately 280 g/m2. The resulting product was cured for 11 1/2 hours at 93C. After this step, the coated abrasive disc was flexed and tested.
Wo 9~/20JG9 2 ~ ~ Q ~ 3 ~ PCI;~US9.1~1~279 Preparation E
First, a 0.76 mm thick vulcanized fibre backing having a 2 . 2 cm diameter center hole was coated with a conventional calcium carbonate filled resole phenolic 5 resin (839~ by weight solids) to form a make coat.
Second, grade 50 abrasive grains were electrostatically coated onto the make coat at a weight of zpproximately 480 g/*. Third, the resulting article was precured for 150 minutes at 93C. A conventional calcium carbonate 10 filled resole phenolic resin (83% by weight solids) was applied over the abrasive grains and the make coat to form a size coat. Fourth, erodible agglomerates were drop coated onto the uncured size coat. The resulting product was cured for 11 1/2 hours at 93C. After this 15 step, the coated abrasive disc was flexed and tested.
Pre~aration F
The pL oce.lul e of Preparation E was repeated except ~that the weight of the abrasive grains was 20 approximately 600 g/m2.
Pren~ration of ThermoPlastic Rods Pre~aration G
A mixture containing 70% by weight medium 25 molecular weight poly (vinyl chloride) (commercially nvailable from Schuman, Bellevue, Ohio) and 30% by weight diisononyl phthalate plasticizer was extruded into strands of fiber having a circular cross-sectional shape having a diameter of about 500 micrometers.
3 0 These strands of f iber were cut into rods having a length of about 1, 500 micrometers, thereby giving an ~spect ratio (length/width or height/diameter) of about 3.0:1Ø
Procedure I for Testinq the Coa~ed Abrasive Discs A coated abrasive disc was installed on a conventional air grinder. The disc was mounted on a beveled aluminum back up pad and used to grind the face of a 18.4 cm by 2.54 cm 304 stainless steel workpiece.
Wo gs120~69 2 1 ~ 0 4 3 ~ PcrluS9~ 279 The air ~, esaule to the grinder was approximately 6 . l kg/cm2. The portion of the coated abrasive overlying the beveled edge of the back up pad contacted the workpiece at a 6. 8 kg load.
The workpiece was weighed before and after an abrading cycle to determine the amount of cut, i.e. how much stainles6 steel was removed in thirty seconds.
When the coated abrasive disc removed less than lO g over two consecutive cycles, the test was dcemed ended.
lO In Tables I through IV, the coated abrasive performance was stated a5 percent of control , i . e., the total amount of metal removed for the control example was equated to 100% and the amounts of metal removed by 1 he coated abrasive articles of the examples of the 15 invention were measured relative to the control. The results are based upon an average of two discs per example .
Procedure II for Testin~ the Coated Abrasive Piscs A coated abrasive disc having a diameter of 17 . 8 cm, a 2.2 cm diameter center hole, and a thickness of .
0.76 mm was attached to an aluminum support pad, and the assembly was installed on a heavy flat test apparatus. This test involved placing a workpiece in 25 proximity to the periphery of the disc at a prescribed angle and at a prescribed rotational speed for a prescribed time. The workpiece was a 304 stainless steel disc having a diameter of approximately 25.4 cm and a thickness of 0.18 cm. The applied load was 30 maintained at 4 . 0 kg. The coated abrasive disc rotated at 5000 rpm. The endpoint of the test was 20 minutes.
The 304 stainless 6teel disc was weighed at two minute intervals during testing. The weight loss associated with the 304 stainless steel disc corr~cpr~n~ to the 35 amount that the coated abrasive disc cut, and served as a measure of the efficiency of the coated abrasive disc .
21 sa~
WO 95/2~69 PCIIUS9~ 279 ~
les l throuqh 4 and CQntrol F~ lcs A and 13 ~ ~ -The results for these examples are set forth in Table I. The abrasive grain used in these examples was grade 50 fused aluminum oxide. The coated abrasive of 5 Control Example A was made according Preparation D
except that it did not contain any erodible agglomerates. Control Example B was a commercially available fibre disc, Three-M-ite Type C coated abrasive disc, available from Minnesota Mining and lO Manufacturing Company, St. Paul, Minnesota.
21 ~4~
WO 95/20169 PCT/US9~/14279 O o o o o o o N N
O j I Q
O
O ~ I I o ~ ~r co * j ¦ N N N N
-' C) ~
C
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~ o _ r ~.1 ~I N rl ~r WO 9~/20~69 2 ~ ~ ~ 4 3 ~ PCT/US9~ 279 es 5 and 6 and Control ~YI les B thrQu:Th G
The results for these examples are set forth in Table II. The abrasive grain used in these examples was fused aluminum oxide. Control Example B was a 5 commercially available fibre disc, Three-M-ite Type C
coated abrasive disc, available from Minnesota Mining and Manuf acturing Company, St . Paul, Minnesota . The coated abrasive disc of Control Example C was made according to Preparation F, except that it did not 10 contain any erodible agglomerates.
Control ExamPle ~
A coated abrasive disc was prepared according to the following procedure. First, a 0.76 mm thick 15 vulcanized fibre backing having a 2 . 2 cm diameter center hole was coated with a composition consisting of a conventional calcium carbonate filled resole phenolic resin (839; by weight solids) to form a make coat.~ The wet coating weight was approximately 270 g/m2. Second, 20 grade 50 fused aluminum oxide abrasive grains were electrostatically coated onto the make coat at a w~ight of approximately 600 g/m2. Third, the resulting abrasive article was precured for 150 minutes at 93C.
Fourth, a composition consisting of 48% resole phenolic 25 resin and 52% KBF~ was applied over the abrasive grains and the make coat at an average weight of approximately 280 g/m2 to form a size coat. The resulting product was cured for 11 1/2 hours at 93C. After this step, the coated abrasive disc was flexed and tested.
CQnt~ol Examl~le E
The coated abrasive disc for Control Example E was made and tested in the same manner as was that of Control Example C, except that a supersize coat was 35 applied over the size coat. The supersize coat consisted of 48% resole phenolic resin and 529i KBF~ and was coated at a weight of approximat~ly 260 g/m2.
21 ~435 Wo 9S/20~69 PCTtr~lsg4t14279 ContrQl EY~mrl~ F
The coated abrasive disc for Control Example F was made and tested in the same manner as was that of Control Example D, except that KBF~ was replaced with an 5 equal amount by weight of K3AlF6. The weight of the size coat was approximately 236 g/m2.
Control F~nle G
The coated abrasive disc for Control Example G ~ras 10 made and tested in the same manner as was that of Control Example E, except that KBF4 was replaced with an equal amount by weight of K3AlF6. The weight of the supersize coat was a~proximately 2~2 /m~.
WO 9~120 169 ~ ~ 8 ~ ~ ~ 5 PCT/I~S9V1~1279 -o o o o o o o o o ,- ~ o ~ ~1 ,i ~r o o C~ .
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~ o -JJ . ~ ! ! ! ! ! ! , , H .,1 ~, _ H æ
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~ r- r _ r 21 8~435 wo 95/204~9 PCT~S94/l~27s ~les 7 and 8 and Control ExamPles H throuah 1.
The coated abrasive aIticles of Example 7 and 8 were prepared according to the procedure described in Preparation F. In Example 7, the erodible agglomerates 5 were made of K13F~. In Example 8, the erodible agglomerates were made of KIAlF6. The abrasive grain used in these examples was grade 50 ceramic aluminum oxide made according to the teachings of U. S . Patent Number 4,314,827. The results for these examples are 10 set forth in Table III.
Control ExamPle H
Control Example ~ was a commercially available fibre disc, Regal coated abrasive disc, available from 15 Ninnesota Mining and Manufacturing Company, St. Paul, Minnesota. This disc contained a size coat that consi6ted o~ 66$ by weight l~a3AlF6, 32$ by weight resole phenolic resin, and 2$ by weight iron oxide pigment.
Control ExamPle I
The coated abrasive disc for Control Example I was made and tested in the same manner as was that of Control Example D, except that the abrasive grain was grade 50 ceramic aluminum oxide. The weight of the 25 size coat was 320 g/m2.
Control ExamPle J
The coated abrasive disc for Control Example J was made and tested in the same manner was that of AS
30 Control Example E, except that the abrasive grain was grade 50 ceramic ~ Tn;n~lTn oxide. The weight of the supersize coat was 232 g/m2.
Control ExamPle K
The coated abrasive disc for Control Example K was made and tested in the same manner as was that of Control Example F, except that the abrasive grain was grade 50 ceramic aluminum oxide. The weight of the size coat was 320 g/m2.
Wo 95/2~469 2 ~ ~ C 4 ~ ~ PCT/US9~114279 Control Exam~le L
The coated abrasive disc for Control Example L was made and tested in the same manner as was that Control }:xample G, except that the abrasive grain was grade 50 5 ceramic aluminum oxide. The weight of the supersize coat was 240 g/m2.
~ WO 9S120469 2 1 8 ~ ~ ~ 5 PCTIUS94111279 rt~ :~
: O ~ ~ , O O ~D
-U
r .. I I I I
,! I I i ,~
r~.~
P~ O
rt j ' j j I j t t j j j j j ~o l l l l l r ~
r~
O
r~
,~' r r~
r WO 9s/20~6g ~ ~ Q 4 3 5 PCT~S9~114279 ExamPles 9 thrDuah 17 These examples demonstrate the use of paraffin and carnauba waxes as binders f or erodible agglomerates .
The abrasive grain used in these examples was grade 50 5 ceramic aluminum oxide.
Control ExamPle M
The coated abrasive for this example was made according to Preparation F, except that the disc did lO not contain any erodible agglomerates.
TI~BLE IV
Weight of Preparation Inorganic erodible 15 Example no. of erodible particulate agglomerate agglomerate material (g/m7) Control M ---- ---- ----9 C CaC0l 120 lO C Na~AlF~ 120 20 12 C NaCl 120 14 C NaCl 120 15 C Na7CO~ 120 16 C Na~SOA 120 25 17 C KCl 120 2 1 804 3~
o ssl20-169 PCT/US9~ 279 Ta 8LE IV ~ Cont inue~
Ratio of binder to particulate material in the Preparation Cut ( % o:~
5 Example no. agglomerate of Disc Control M) Control M ---- ---- 100 930:70 F 135 lO30:70 F 179 1130:70 F 456 10 12 30: 70 F 233 1325: 75 F 258 1425:75 F 254 1525: 75 F 154 1625: 75 F 150 15 17 25:75 F 242 The data in Table IV show that the coated abrasive discs containing the carnauba wax had a higher initial 20 cut than corresponding discs containing paraffin wax.
r les 18 and 19 and Control ExamPles N and o These examples demonstrate the use of clay as a binder f or the erodible agglomerate . The coated 25 abrasive was tested according to the following ~,cedu,~. The coated abrasive was first converted into a 7.6 cm by 335 cm endless belt. The belt was installed on a constant load surface grinder. A pre-weighed, 304 stainless steel workpiece, approximately 30 2.5 cm by 5 cm by 18 cm, was mounted in a holder, positioned vertically, with the 2.5 cm by 18 cm face confronting approximately 36 cm diameter 60A durometer serrated rubber contact wheel with one on one lands over which was entrained the coated abrasive belt. The 35 workpiece was then reciprocated vertically through a 18 cm path at the rate of 20 cycles per minute, while a spring loaded plunger urged the workpiece against the belt with a load of 9 kg as the belt was driven at a rate of about 2050 m/min. After one minute of grinding WO 95/20469 ~ t 8 0 ~ ~ 5 PCT/US9~114Z79 time, the workpiece holder assembly was removed and reweighed, the amount of stock removed calculated by subtracting the weight after grinding from the original weight. A new, pre-weighed workpiece and holder were 5 then mounted on the equipment. The experimental error on this test was +/- 10%. The test was deemed complete in 20 minutes. The test results are set forth in Table V.
Exam~le 18 Erodible agglomerates were made according to the following procedure. Into a blade mixer were charged 9 kg of Peerless #14 clay, 22.5 kg of water, and 3.6 kg of graphite. The charge was thoroughly mixed; then Z7 15 kg of KBF4 was added slowly, and the charge mixed until it was homogeneous. The resulting mixture was then placed into 1.25 cm trays and dried at 80C for approximately 12 hours. The resulting dried mixture was crushed and screened. The crushed, screened 20 agglomerates were heated at 200C overnight. The agglomerates were screened such that the average particle size thereof was -30 +48.
A coated abrasive article was prepared according to the following procedure. A composition containing 25 849~ by weight solids and consisting of 48% resole phenolic resin and 52% calcium carbonate was applied to an X weight cotton backing at a wet weight of 290 g/m2 to f orm a make coat . The erodible agglomerates were drop coated into the make coat at a weight of 105 g/m2.
30 Grade 50 ceramic aluminum oxide was electrostatically coated onto the make coat at a weight of 470 g/m2. The resulting article was precured for 90 minutes at 88C.
A composition containing 83% by weight solids and consisting of resole phenolic resin and calcium 35 carbonate filler was applied over the abrasive grains at a wet weight of 293 g/m2 to form a size coat. The resulting article was precured for 90 minutes at 88C
and then final cured for 10 ~hours at 100C. The product was then f lexed .
~ wo 95l20469 2 1 8 0 ~ 3 5 PCr/US94/14279 r~le 19 The coated abrasive article of Example 19 was ma~e in the same manner as was that of Example 18, except that the abrasive grain was a grade 50 fused alumina.
Control N
The coated abrasive article of Control Example N
was a grade 50 ~llL~,e r~ ite Polycut Resin Bond Cloth Product, commercially available from Minnesota Mining 10 and Manufacturing Company, St. Paul, Minnesota. This product contained a KBF4 grinding aid.
Control 0 The coated abrasive article of Control Example 0 15 was a grade 50 Three-M-ite Resin Bond Cloth Product, commercially available from Minnesota Mining and Manufacturing Company, St. Paul, Minnesota.
TAPLE V
Example no. Cut (9c of Control N) Control N 100 Control 0 67 Exam~les 20 throuah 23 and ComParative Exam~les P
throuqh S
Coated abrasives discs of Examples 20 through 23 30 were made according to the following procedure. A
resole phenolic/acrylic latex adhesive was applied over the abrasive side of a grade 50 coated abrasive fibre disc. The disc was commercially available from Minnesota Mining and Manufacturing Company, St. Paul, 35 Minnesota. Then polyvinyl chloride (PVC) particles (commercially available from the BF Goodrich Company) were drop coated onto this adhesive. For Example 20, the PVC particles had an average size of 120 micrometers, while in the 1~ ;n;n7 examples, the PVC
WO 95120469 2 1 ~ 0 4 3 5 PcrruS9411J279 particles had an average size of 180 micrometers. The resulting coated abrasive disc was heated or three hours at 95C to solidify the adhesive. The disc was then f lexed and tested . The discs of the Comparative 5 Examples did not contain any adhesive or erodible agglomerate. In all of the Comparative Examples, the grit was of grade 50.
The f ibre discs of these examples were tested according to the following procedure. The discs were lO mounted on a beveled aluminum back up pad and used to grind the face of a 2.5 cm by 18 cm 310 stainles6 steel workpiece. The disc was driven at 5,500 rpm with the portion of the disc overlaying the beveled edge of the back up pad contacting the workpiece at 9 . l kg force to 15 generate a disc wear path of about 14 0 cm . Each disc was used to grind a separate workpiece for one minute each until the cut in a one minute time interval was less than four grams. The total cut for the grinding test is set f orth in Table VI .
21 8~5 WO 95/20~69 P~T/US9~ 279 V
o (~ o N
Ul ~ ~1 O C~ Ul N N
Iq N r~) N ~ N ~1 ~1 r _ I _ r .
.,' . ~
~ 3 P C.) P3 ~
. ~
-- 'i I i ! I
.,' o ~o ~) 10 h R ~ ~ h R '~ ~
r ,~ h ,~ h ul- ~ R ~ R R
'~~ I h q~ q~ I h q~
, ~ U, ~ U
R ~ r I L X E~ ~ L ~ E~
, ,~ O ~I N ~ ~
O O O O
O U U U U
WO95l20J~9 2 t ~ Q ~ 3 ~ PCT/US95/l~279 The data in Table VI show that the addition of the erodible agglomerate grinding aid significantly increases the abrading characteristics of coated abrasive discs.
Control E~Arnle T and Examl~le 24 Coated abrasive discs for Control Example T were prepared according to the following ~l~cc:duLe. A 0.76 mm thick vulcanized fibre backing having a ~ r- ~r of 10 17 . 8 cm and 2 . 2 cm diameter center hole was coated with a conventional calcium carbonate filled resole phenolic resin (75% by weight solids) to form a make coat. The wet coating weight was approximately 164 g/m2. Grade 36 ceramic aluminum oxide abrasive grains were 15 electrostatically coated into the make coat at a weight of approximately 740 g/mZ. The resulting article was "~ UL~d for 150 minutes at a t~ eLaLuL~ of 93C. A
composition consisting of 32% resole phenolic resin (75% by weight solids), 50 . 2% cryolite (trisodium 20 hexafluoroaluminate), 1.5% red iron oxide, 13.8%
methoxy propanol (85% 2-methoxy propanol and 15%
water), and 2.5% water was applied over the abrâsive grains and the make coat at an average weight of approximately 658 g/m2 to form a size coat. The 25 resulting product was cured for 11 1/2 hours at a temperature of 93 C. An aqueous composition consisting of 29 . 2% epoxy resin (a composition containing a diglycidyl ether of bisphenol A epoxy resin coatable from water, the composition containing approximately 30 60% solids and 40% water, and having the trade designation "CrqD 35201", available from Rhone-Poulenc, Inc.), 0.35% 2-ethyl-4-methyl imidazole ("EMI-24", commercially available from Air Products and Chemicals, Inc. ), 53 . 59c KBF4 (98% pure micropulverized, in which 35 95% by weight passes through a 325 mesh screen and 10096 by weight passes through a 200 mesh screen), 14.1%
water, 0 . 75% sodium dioctyl sulfosuccinate dispersion agent ("Aerosol OT", commercially available from Rohm and Haas), and 2.3% red iron oxide was roll coated over ~ wo gs/20469 2 i ~ ~ 4 3 ~ PCT/US94114279 the size coat and then cured at a temperature of 115C
for go minutes to form a supersize coat. After this step, the coated abrasive di6cs were flexed and humidified at 45% relative humidity for one week prior 5 to testing.
Example 24 was made according to the ~LuceduL.3 for making Control Example T, with two major exceptions.
After the abrasive grains had been applied, polyvinyl chloride rods t500~ diameter by 1500~ length) were 10 electrostatically coated into the make coat precursor at a coating weight of 74 g/m2. No supersize coat was applied to the article of Example 24.
Ploce.luLe II was utilized to test the abrasive articles of these examples. Three or four discs of 15 each type were tested and the results set forth in Table VII.
TABLE VII
Example No . Initial cut ( 2 min . ) Total cut (% of control) (96 of control) 20 Control T 100 100 Various modif ications and alterations of this 25 invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein.
Claims (15)
1 A coated abrasive article comprising a backing, said backing having at least one roajor surface, erodible agglomerates, and abrasive grains, wherein said erodible agglomerates and abrasive grains bear on and adhere to said at least one major surface of said backing, whercin said erodible agglomerates consist essentially of a grinding aid, do not contain abrasive particles having a Moh's hardness in excess of 7, and are in the shape of rods, said rods having an aspect ratio which ranges from 0 5:1.0 to 10.0:1.0, whercin said grinding aid has a Moh's hardness of less than 7 and is selected from the group consisting of thermoplastic materials.
2. The coated abrasive article of Claim 1, wherein said erodible agglomerates and said abrasive grains are adhered to said backing by a make coat and a size coat.
3. The coated abrasive article of Claim 1, wherein said erodible agglomerates and said abrasive grains are adhered to said backing by 2 single binder.
4. The coated abrasive article of Claim 1, wherein said erodible agglomerates are disposed above said abrasive grains.
5. The coated abrasive article of Claim 1, wherein said erodible agglomerates are disposed between said abrasive grains.
6. The coated abrasive article of Claim 1, wherein said erodible agglomerates are disposed between and above said abrasive grains.
7. The coated abrasive article of Claim ?, wherein said erodible agglomerates and said abrasive grains are adhered to said backing by a single binder.
8. The coated abrasive article of Claim 1, wherein said grinding aid is selected from the group consisting of halogenated thermoplastic materials.
9. The coated abrasive article of Claim 8, wherein said grinding aid is selected from the group consisting of poly(vinyl chloride), halogenated waxes, polyvinylidene chloride, and polyvinylidene fluoride.
10. The coated abrasive article of Claim 1, wherein said abrasive grains are selected from the group consisting of diamond, cubic boron nitride, boron carbide, alumina zirconia, tungsten carbide, silicon carbide, aluminum oxide, silicon nitride coated silicon carbide, garnet, and mixtures thereof.
11. The coated abrasive article of Claim 1, wherein said abrasive grains have a Mohs' hardness of at least about 7.
12. The coated abrasive article of Claim 1, wherein each of said erodible agglomerates and each of said abrasive grains has a maximum dimension and the ratio of the maximum dimension of said erodible agglomerates to the maximum dimension of said abrasive grains ranges from about 2.5:1.0 to about 0.5:1Ø
13. The coated abrasive article of Claim 1, wherein the ratio of volume of said erodible agglomerates to volume of said abrasive grains ranges from about 5:95 to about 95:5.
14. The coated abrasive article of Claim 1, wherein the ratio of volume of said erodible aqglomerates to volume of said abrasive grains ranges from about 30:70 to about 70:30.
15. The coated abrasive article of Claim 8, wherein said halogenated thermoplastic material is poly (vinyl chloride) .
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US18830294A | 1994-01-28 | 1994-01-28 | |
| US08/188,302 | 1994-01-28 | ||
| PCT/US1994/014279 WO1995020469A1 (en) | 1994-01-28 | 1994-12-12 | Coated abrasive containing erodible agglomerates |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2180435A1 true CA2180435A1 (en) | 1995-08-03 |
Family
ID=22692601
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002180435A Abandoned CA2180435A1 (en) | 1994-01-28 | 1994-12-12 | Coated abrasive containing erodible agglomerates |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0741632A1 (en) |
| JP (1) | JPH09508324A (en) |
| CA (1) | CA2180435A1 (en) |
| WO (1) | WO1995020469A1 (en) |
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| WO1998010896A1 (en) * | 1996-09-11 | 1998-03-19 | Minnesota Mining And Manufacturing Company | Abrasive article and method of making |
| CN1085575C (en) * | 1996-09-11 | 2002-05-29 | 美国3M公司 | Abrasive article and its method of making |
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| US6186866B1 (en) | 1998-08-05 | 2001-02-13 | 3M Innovative Properties Company | Abrasive article with separately formed front surface protrusions containing a grinding aid and methods of making and using |
| US7169031B1 (en) * | 2005-07-28 | 2007-01-30 | 3M Innovative Properties Company | Self-contained conditioning abrasive article |
| US7494519B2 (en) * | 2005-07-28 | 2009-02-24 | 3M Innovative Properties Company | Abrasive agglomerate polishing method |
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| WO2016201104A1 (en) | 2015-06-11 | 2016-12-15 | Saint-Gobain Ceramics & Plastics, Inc. | Abrasive article including shaped abrasive particles |
| KR102313436B1 (en) | 2016-05-10 | 2021-10-19 | 생-고뱅 세라믹스 앤드 플라스틱스, 인코포레이티드 | Abrasive particles and method of forming the same |
| SI3455321T1 (en) | 2016-05-10 | 2022-10-28 | Saint-Gobain Ceramics & Plastics, Inc. | Methods of forming abrasive particles |
| WO2018064642A1 (en) | 2016-09-29 | 2018-04-05 | Saint-Gobain Abrasives, Inc. | Fixed abrasive articles and methods of forming same |
| US10759024B2 (en) | 2017-01-31 | 2020-09-01 | Saint-Gobain Ceramics & Plastics, Inc. | Abrasive article including shaped abrasive particles |
| US10563105B2 (en) | 2017-01-31 | 2020-02-18 | Saint-Gobain Ceramics & Plastics, Inc. | Abrasive article including shaped abrasive particles |
| EP3642293A4 (en) | 2017-06-21 | 2021-03-17 | Saint-Gobain Ceramics&Plastics, Inc. | Particulate materials and methods of forming same |
| CA3087057C (en) * | 2017-12-27 | 2023-03-21 | Saint-Gobain Abrasives, Inc. | Coated abrasives having aggregates |
| WO2020128708A1 (en) * | 2018-12-18 | 2020-06-25 | 3M Innovative Properties Company | Coated abrasive articles and methods of making coated abrasive articles |
| JP2020168664A (en) * | 2019-04-01 | 2020-10-15 | 三洋展創工業株式会社 | Manufacturing method of polishing sheet |
| KR20220116556A (en) | 2019-12-27 | 2022-08-23 | 세인트-고바인 세라믹스 앤드 플라스틱스, 인크. | Abrasive articles and methods of forming same |
| US20230166384A1 (en) * | 2020-05-11 | 2023-06-01 | 3M Innovative Properties Company | Abrasive body and method of making the same |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT370024B (en) * | 1980-04-01 | 1983-02-25 | Swarovski Tyrolit Schleif | GRINDING BODY WITH ABRASIVE GRAIN |
| JPS59156670A (en) * | 1983-02-22 | 1984-09-05 | ノ−トン カンパニ− | Grind stone |
| US5110322A (en) * | 1989-09-13 | 1992-05-05 | Norton Company | Abrasive article |
| DE69123749T2 (en) * | 1990-10-09 | 1997-06-05 | Minnesota Mining & Mfg | EDMABLE AGGLOMERATE CONTAINING COATED ABRASIVE |
-
1994
- 1994-12-12 EP EP95904884A patent/EP0741632A1/en not_active Withdrawn
- 1994-12-12 WO PCT/US1994/014279 patent/WO1995020469A1/en not_active Application Discontinuation
- 1994-12-12 JP JP7520037A patent/JPH09508324A/en active Pending
- 1994-12-12 CA CA002180435A patent/CA2180435A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| WO1995020469A1 (en) | 1995-08-03 |
| JPH09508324A (en) | 1997-08-26 |
| EP0741632A1 (en) | 1996-11-13 |
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| FZDE | Discontinued |