CN114829069A - Abrasive article - Google Patents

Abstract

An abrasive article is disclosed. The abrasive article has a backing substrate. The abrasive article also has a laminate joined to the backing substrate. The laminate comprises a hot melt polymer. The abrasive article also has a cured resin composition joined to the laminate opposite the backing substrate. The abrasive article also has abrasive particles bonded to the cured resin composition.

Description

Abrasive article

Background

It is common for dry sanding operations to generate large amounts of airborne dust. To minimize this airborne dust, abrasive disk tools are typically used while a vacuum is drawn through the abrasive disk from the abrasive side, through the back of the disk, and into a dust collection system. To this end, many abrasives have holes switched into them to facilitate such dusting. As an alternative to converting the dust extraction apertures into the abrasive disc, there are commercial products in which the abrasive is coated onto the fibers of a mesh knitted backing in which the loops are knitted into the back of the abrasive article. The loop serves as the loop portion of the hook and loop attachment system for attachment to the tool. When used with substrates that are known to be heavily filled with conventional abrasives, the mesh products are known to provide excellent dusting and/or anti-loading characteristics. However, cutting and/or life performance is still lacking. Accordingly, there is a need for a mesh product that provides enhanced cutting and/or life performance while exhibiting excellent dusting.

Drawings

The drawings are generally shown by way of example, and not by way of limitation, to the various embodiments discussed in this document.

Fig. 1 is a perspective view of an abrasive article according to one example of the present disclosure.

Fig. 2 is a side cross-sectional view of an abrasive article according to various embodiments of the present disclosure.

Fig. 3 is a schematic diagram illustrating a step-by-step construction of an abrasive article according to various embodiments of the present disclosure.

Fig. 4A-4I are side cross-sectional views of a portion of an abrasive article according to various embodiments of the present disclosure.

Fig. 5-6 are side cross-sectional views of abrasive articles according to embodiments of the present disclosure.

Fig. 7A to 7D show examples of laminated backings.

Fig. 8A-8C show cross-sectional views of coated abrasive articles according to embodiments of the present invention.

Fig. 9A-9B illustrate a laminate backing according to one embodiment of the present invention.

FIG. 10 illustrates a method for making a coated abrasive article according to one embodiment of the present invention.

It should be understood that numerous other modifications and examples can be devised by those skilled in the art that will fall within the scope and spirit of the principles of this disclosure. The figures may not be drawn to scale.

Description of the invention

Generally, coated abrasive articles have abrasive particles secured to a backing. The coated abrasive article can include a backing having two opposed major surfaces and an abrasive layer secured to one of the major surfaces. The abrasive layer typically includes abrasive particles and a binder that secures the abrasive particles to the backing. One common construction is a backing with a resin-based binder.

For example, phenolic resins and polyethylene terephthalate (PET) films are two common materials that can be used to make abrasive products. However, phenolic resins do not bond well to ordinary untreated polyester or PET films.

Embodiments described herein relate to an abrasive article that not only maintains the dusting advantages of abrasives on a mesh backing, but also exhibits the abrasive performance (cut and/or life) advantages of conventional coated abrasive articles. This combination of benefits (dust removal and cutting and/or life) is possible because the construction of the abrasive articles described herein allows for the coating of abrasives on a wider variety of backing materials with better performance by applying a laminate layer between the backing material and the resin coating.

The present disclosure provides articles including laminates that can serve as primer layers for backings, such as for improving adhesion to a make resin layer (e.g., a phenolic resin layer) in an abrasive article.

FIG. 1 is a perspective view of one example of an abrasive article, designated by the numeral 100. As shown, abrasive article 100 includes: a substrate 110 comprising strands forming first void spaces 270 (see fig. 2) therebetween; and an abrasive layer 120 comprising a laminate joined to the substrate 110; a resin joined to the laminate opposite the fabric substrate 110; abrasive particles bonded to the resin; and a plurality of void spaces extending through the laminate so as to coincide with the void spaces in the substrate 110. In one embodiment, substrate 110 is a fabric substrate. The plurality of void spaces extending through the laminate coincident with the void spaces in the fabric substrate 110 allow airflow through the article 100 at a rate of, for example, at least 0.1L/s (e.g., at least 0.2L/s, at least 0.4L/s, at least 0.6L/s, at least 1L/s; or from about 0.1L/s to about 1L/s, from about 0.25L/s to about 0.75L/s, from about 0.5L/s to about 1L/s, from about 1L/s to about 2L/s, about 1.5L/s, or about 3L/s) so that, in use, dust can be removed from the abrasive surface by the abrasive article.

Fig. 1 illustrates a relatively simple pattern that may be produced with the abrasive layer 120. But many patterns are conceivable. For example, abrasive articles 100 having various patterns in abrasive layer 120 are described and shown in co-pending U.S. provisional patent 62/803,871 filed on 11/2/2019. As can be seen, the abrasive layer 120 may include a plurality of pattern elements 120, which may or may not be repeated over the entire surface of the abrasive article 100. Each pattern element 120 may be made up of one or more subelements. Different pattern elements 120 within the same abrasive article may be provided with the same or different abrasive particles 250 or other additives (e.g., different abrasive grades, blends of abrasive particles 250, fillers, grinding aids, etc.) as desired for a given application. While the depicted article is presented in the form of a disc, it should be understood that the abrasive article may take any form (e.g., a sheet or a belt).

FIG. 2 illustrates a cross-sectional view of the abrasive article, indicated by the numeral 100, taken along the line 2-2 of FIG. 1, as viewed in the direction of the arrows. As shown in fig. 2, abrasive article 100 comprises: a fabric substrate 110 comprising strands 260 forming first void spaces 270 between the strands 260; a laminate 230 joined to the fabric substrate 110; a cured resin composition 240 (e.g., a cured product of a phenolic resin) joined to the laminate 230 opposite the fabric substrate 110; abrasive particles 250 bonded to the cured resin composition 240; and a plurality of second void spaces 280 extending through the laminate so as to coincide with the first void spaces 270 in the fabric substrate 110. In some cases, the fabric substrate 110 includes a laminate 230A that does not include the cured resin composition 240 joined to the laminate 230A.

Abrasive particles 250 are at least partially embedded in cured resin composition 240. As used herein, the term "at least partially embedded" generally means that at least a portion of the abrasive particles are embedded in the cured resin composition such that the abrasive particles are anchored in the cured resin composition. In some embodiments, the abrasive particles 250 are applied together to the laminate 230 in the form of a slurry composition. In such embodiments, abrasive particles 250 may optionally be oriented by the influence of a magnetic field prior to curing of resin 240A. See, e.g., commonly owned U.S. patent publication nos. 2018/080703, 2018/080756, 2018/080704, 2018/080705, 2018/080765, 2018/080784, 2018/136271, 2018/134732, 2018/080755, 2018/080799, 2018/136269, 2018/136268.

As shown in fig. 2, the abrasive article 100 includes a first side 210 joined to a laminate 230; and a second side 212 opposite the first side 210. Second side 212 may comprise a portion of a two-part hook and loop attachment system (not shown).

FIG. 3 illustrates an example of a method by which the abrasive article 100 shown in FIG. 1 may be constructed in a step-wise manner.

In a first step, the laminate 230 is joined to the fabric substrate 110, which includes strands 260 forming first void spaces 270 between the strands 260. The laminate 230 may be joined to the fabric substrate 110 by any suitable means, including first applying a suitable adhesive layer (not shown) to the substrate 110, and then applying the laminate 230; fusing the laminate to the fabric substrate 110; printing the laminate 230 onto the fabric substrate 110; or any combination of the foregoing methods for joining the laminate 230 to the fabric substrate 110. Among other things, the laminate 230 is used to provide a substantially flat landing for the uncured (or partially cured) resin composition 240A such that the uncured resin composition 240A deposited on the laminate 230 remains on the surface and does not have the opportunity to move, for example, into the spaces 270 between the strands 260 of the fabric substrate 110.

In a second step, the uncured resin composition 240A is joined to the laminate 230 opposite the fabric substrate 110. The uncured resin composition 240A may be joined to the laminate 230 by any suitable means, including using a (rotating) stencil/screen printing roller, a flat screen/stencil, or printing the uncured resin composition 240A directly onto the laminate 230, or using a combination of two or more suitable methods (e.g., extrusion die coating, curtain coating, knife coating, gravure coating, and spray coating) for joining the uncured resin composition 240A to the laminate 230 opposite the fabric substrate 110.

In the third step, abrasive particles 250 are bonded to uncured resin composition 240A by any suitable method, including drop coating, electrostatic coating, magnetic coating, and other mechanical methods of mineral coating. For example, abrasive particles 250 may be deposited onto uncured resin composition 240A by: simply dropping the abrasive particles 250 onto the uncured resin composition 240A; electrostatically depositing abrasive particles 250 onto uncured resin composition 240A; or using a combination of two or more suitable methods for bonding abrasive particles 250 to uncured resin composition 240A. In some embodiments, abrasive particles 250 may be optionally oriented under the influence of a magnetic field, as previously indicated, prior to curing of resin 240A.

In a fourth step, uncured resin composition 240A is cured such that abrasive particles 250 are at least partially embedded in cured resin composition 240 and substantially permanently attached. The uncured resin composition 240A may be cured by any suitable curing mechanism, including thermal curing, photochemical curing, moisture curing, or a combination of two or more curing mechanisms, to form the cured resin 240. However, if the uncured resin composition 240A is cured by any means that does not include heating, a fifth step (not shown) may be required to effect migration of the laminate 230 away from the void spaces 270 between the strands 260.

During the curing process, at least a portion of the laminate 230 not covered by the cured resin composition 240 migrates away from the first void spaces 270 between the strands 260, thereby opening a plurality of second void spaces 280 extending through the laminate coincident with the first void spaces 270. Thus, when the cured resin composition 240 is not present over the first void space 270, the laminate 230 avoids the first void space 270. Further, when the cured resin composition 240 is located over the first void space 270, the laminate 230 covers the first void space 270.

While FIG. 3 illustrates an example of one method by which the abrasive article 100 shown in FIG. 1 may be constructed in a step-wise manner, methods are also contemplated in which one or more of the steps described herein may be accomplished in a single step or in which certain steps may be performed in a different order than illustrated in FIG. 3. For example, the uncured or partially cured resin composition 240A may first be joined/deposited to the laminate 230 to form a first composite. The first composite comprising uncured or partially cured resin 240A and laminate 230 may then be joined to the fabric substrate 110 in a single step, followed by steps 3 and 4. Alternatively, the laminate 230 and the uncured or partially cured resin composition 240A may be co-deposited (e.g., co-extruded) onto the fabric substrate 110 prior to steps 3 and 4. In yet another alternative, abrasive particles 250 may first be bonded with uncured or partially cured resin composition 240A to form a second composite. In this case, the uncured or partially cured resin composition 240A may first be bonded/deposited onto the removable liner. Abrasive particles 250 may then be bonded/deposited onto uncured or partially cured resin composition 240A to form a second composite. A second composite comprising abrasive particles 250 bonded with an uncured or partially cured resin composition 240A may then be bonded/deposited to the laminate 230 to produce a third composite. A third composite comprising abrasive particles 250 joined with uncured or partially cured resin composition 240A, which in turn is joined to laminate 230, may then be joined to fabric substrate 110 in a single step, followed by steps 3 and 4.

Fig. 4A-4I illustrate various arrangements (non-exhaustive) that may occur when the laminate 230 not covered by the cured resin composition 240 migrates away from the first void spaces 270 between the strands 260. For example, the laminate 230 may be at least partially wrapped around the strands 260 to create the second void spaces 280, thereby leaving the first void spaces 270 open, as shown in fig. 4B, 4D, 4F, 4G, 4H, and 4I. In such cases, the laminate 230 extends only over the strands 260, not over the first void spaces 270. And in some cases, the laminate 230 may be wrapped around some strands 260 and not wrapped around other strands, as shown in fig. 4I.

FIG. 5 illustrates an example of an abrasive article, designated by the numeral 200, that incorporates all of the features shown in FIG. 1, which for brevity will not be discussed, and further incorporates a size layer 510 having size layer void spaces 520 that coincide with the second void spaces 280. FIG. 6 illustrates an example of an abrasive article, designated by the numeral 300, that incorporates all of the features shown in FIG. 5, which for brevity will not be discussed again, and further incorporates a supersize layer 610 having a supersize layer void space 620 that coincides with the size layer void space 520 and the second void space 280.

The layer configurations described herein are not intended to be exhaustive, and it should be understood that layers may be added or removed with respect to any of the examples depicted in fig. 1-3.

In general, the laminate 230 can be any material (e.g., a nonwoven or woven web or film) that provides a landing surface for the uncured (or partially cured) resin composition 240A such that the uncured resin composition 240A deposited on the laminate 230 remains on the surface and does not have the opportunity to, for example, migrate into the void spaces 270 between the strands 260 of the fabric substrate 110; but at the same time migrate away from the void spaces 270 between the strands 260, for example during the curing process to form the cured resin composition 240, thereby opening a plurality of second void spaces 280 extending through the laminate coincident with the first void spaces 270. Suitable materials for the laminate 230 include heat-fusible materials, including polyester heat-fusible materials (e.g., HM4185 polyester hot-melt adhesives available from Bostik, Wauwatosa, WI), polyamides, Ethylene and Acrylic Acid (EAA) copolymers, ethyl methyl acetate, or vinyl acetate ethyl esters. The laminate 230 may be provided, for example, in the form of a continuous non-apertured sheet, or as a continuous apertured sheet, thereby providing apertures in the areas adjacent to or surrounding the pattern elements.

The laminate 230 should be adhered to both the mesh backing layer and the resin layer. Failure at either layer will cause the abrasive particles to delaminate from the backing. This is particularly important for extrusion lamination of hot melt films, which results in a non-porous laminate separating the make layer from the backing.

The composition and process used to adhere the laminate to the backing layer can affect the performance of the abrasive article. Some important parameters include reopening of the laminate during curing of the primer resin, sufficient adhesion of the laminate to the backing, and flatness of the laminate.

As described above with respect to fig. 3, reopening of the laminate during curing of the make resin promotes dust collection during abrasive operations. Reopening of the laminate can be controlled by selecting a material that has a melting point below the melting point or degradation temperature of the coated resin described above, but high enough so that the laminate will not melt or wash away during resin curing and abrasive use. If the melting point of the laminate is too low, it can also lead to sagging of the laminate/make coat in the open areas, which can lead to significant surface defects with respect to make coat applications. In addition, the thickness of the laminate coating is important-if the coating is too thick, it will not open. If it is too thin, the resin can penetrate the backing layer.

Adhesion to the mesh backing may reduce delamination of the abrasive article. Adhesion can be increased by extrusion temperature, nip pressure, die position, and the chemical composition of the laminate.

The flatness of the laminate layer also improves the adhesion of the resin and reduces shelling of the abrasive particles from the resulting abrasive article. The roughness of the previously laminated coated abrasive article was above 30 μm Ra. The methods and embodiments described herein can achieve roughness values below about 20 μm Ra, or even as low as 10 μm Ra.

Fig. 7A and 7B show two different laminate backings. Fig. 7A shows a poorly laminated mesh backing 710, where the laminate is not a continuous layer. Fig. 7B shows a laminated mesh backing 720 resulting from co-extruding the mesh backing with a laminate. The laminate backing 720 has a flatter surface than the laminate backing 710 and the laminate layers of the laminate backing 720 are more continuous along the surface.

Extrusion can increase laminate reopening, reduce delamination of the abrasive particles, and can also reduce the creation of weak points between the laminate and the mesh backing. However, extrusion does not result in a porous laminate. This prevents the primer resin from penetrating the laminate layer and contacting the mesh web after coating, and also results in high surface tension, such that the re-opening process of the laminate layer is prone to incomplete re-opening and delamination if incorrect conditions are used. Fig. 7C shows the extrusion laminated backing 730 not completely open. Fig. 7D shows delamination of the make coat and abrasive particles on the extrusion laminated backing 740.

Improving lamination reopening, adhesion, and flatness can provide abrasive articles with better feature resolution and reduce resin penetration. Improvements in these areas can be achieved by modifying the chemical make-up of the laminate and the process conditions used to apply the laminate.

In one embodiment, the laminate comprises a hot melt polymeric resin such as a polyamide, a polyester, a poly [ ethylene acrylic acid ] copolymer, a poly (ethylene-acrylate) copolymer, a poly (ethyl methyl acetate) copolymer, a polyolefin, polyurethane polyethylvinyl acetate, a polyethylene acrylate copolymer, an ethylene methacrylic acid copolymer, an acid modified ethylene terpolymer, an anhydride modified vinyl acylate, a vinyl acetate polymer, or a blend thereof. The laminate may also contain additives such as ethyl acetoacetate. In one embodiment, the laminate has at least 5% ethyl acetoacetate.

In one embodiment, the laminate has a melting temperature between about 50 ℃ and about 150 ℃. In another embodiment, the laminate has a melting temperature between about 80 ℃ to about 110 ℃.

In one embodiment, the coat weight of the laminate is between about 10 grams per square meter and about 60 grams per square meter (gsm). In one embodiment, the coat weight of the laminate is between about 15gsm and about 40 gsm. In one embodiment, the coat weight of the laminate is between about 15gsm and about 25 gsm. In one embodiment, the coating thickness of the laminate is between about 10 μm and about 50 μm. In one embodiment, the coating thickness of the laminate is between about 10 μm and about 20 μm.

While mesh-based backings are suitable for applications where dust collection is a priority, it is also expressly contemplated that the laminates of the embodiments described herein may also be suitable for other coated abrasive article constructions used in other applications.

Coated abrasive articles typically have a backing with an abrasive layer that includes a make coat, a size coat, and abrasive particles. In making such coated abrasive articles, a make layer comprising a first binder precursor may be applied to a major surface of the backing. Abrasive particles are then at least partially embedded in the make layer (e.g., by electrostatic coating), and the first binder precursor is cured (i.e., crosslinked) to secure the particles to the make layer. A size layer comprising a second binder precursor may be applied to the make layer and abrasive particles, followed by curing the second binder precursor and possibly further curing the first binder precursor.

Another type of coated abrasive article is formed by applying an abrasive layer provided as a slurry consisting of a binder precursor and abrasive particles to a major surface of a backing and then curing the binder precursor.

It is known to pre-treat the backing material with a primer in order to enhance the adhesion between the backing and the applied layer, such as a make coat or laminate layer. It is expressly contemplated that such pretreatment may be applied to the backing layer of the abrasive articles described herein in addition to or prior to the application of the laminate layer. For example, a plasma or corona treatment may be applied to the backing prior to application of the laminate layer. Some examples of priming treatments are described in co-owned pending PCT application IB2019/056300 filed on 23.7.7.2019, which claims priority to us provisional 62/702029 filed on 23.7.23.2018, which is incorporated herein by reference.

Some examples of typical backing treatments are a backsize layer (i.e., a coating on a major surface of the backing opposite the abrasive layer), a presize layer or tie layer (i.e., a coating on the backing disposed between the abrasive layer and the backing), and/or an impregnant to saturate the backing. Sub-glue is similar to the saturant except that it is applied to a previously treated backing.

Application of the backing treatment composition can be performed in a variety of ways, including brushing, spraying, roll coating, curtain coating, gravure coating, and knife coating. The coated backing may then be treated at a temperature sufficient to dry and at least partially crosslink the coating for a period of time to form a primer layer on the backing.

In some embodiments, the backing material undergoes a surface treatment. Useful surface treatments include electrical discharges (such as plasma, glow discharge, corona discharge, dielectric barrier discharge, or atmospheric pressure discharge) in the presence of a suitable reactive or non-reactive atmospheric environment; ultraviolet light exposure, electron beam exposure, flame discharge and gluing (scuffing). The surface treatment may be applied at the time of manufacture of the polyester film backing or in a separate process. In some embodiments, the polyester film backing is surface treated using corona discharge. Examples of useful corona discharge methods are described in U.S. patent 5,972,176(Kirk et al).

Depending on the choice of abrasive layer and backing (treated or untreated), the abrasive layer may partially separate from the backing during abrading, resulting in the release of abrasive particles. This phenomenon is known in the abrasive art as "shelling". In most cases, shelling is undesirable because shelling results in a loss of performance. A tie layer is sometimes disposed between the backing and the abrasive layer. See, for example, U.S. patents 5,304,224(Harmon) and 5,355,636 (Harmon). Bonding layers have been used to solve the problem of shelling in some coated abrasive articles, for example, U.S. Pat. No. 7,150,770(Keipert et al)

The primer layer may contain one or more additives, if desired. In some embodiments, the primer layer useful in the practice of the present disclosure comprises at least one of an organic solvent, a surfactant, an emulsifier, a dispersant, a catalyst, a rheology modifier, a density modifier, a cure modifier, a diluent, an antioxidant, a heat stabilizer, a flame retardant, a plasticizer, a filler, a polishing aid, a pigment, a dye, an adhesion promoter, an antistatic additive. In various embodiments, the presence or absence of certain of these additives can reduce cost, control viscosity, or improve physical properties. In some embodiments, the primer layer comprises a surfactant.

It is expressly contemplated that a laminate layer may be applied to the coated abrasive article in addition to or in place of the make layer. Applying the laminate layer to the backing may provide additional functionality to the coated abrasive article. However, as shown in the examples, the laminate may also replace the primer layer or provide functional improvement to the backing.

Fig. 8A-8C show cross-sectional views of coated abrasive articles according to embodiments of the present invention.

As shown in fig. 8A, in one embodiment, an abrasive article 800 has a backing 810, a laminate layer 820 secured to a major surface 815 of the backing 810, and an abrasive layer 830 secured to the laminate 820. The abrasive layer 830 includes abrasive particles 860 secured to the article 800 by a make layer 840 and a size layer 850. In one embodiment, the backing 810 is pretreated, such as by a primer, such as a backsize layer, a presize layer, a tie layer, an impregnant, and/or a sub-size treatment.

The primer or pretreatment of the backing is considered to be different from the application of the laminate to the backing. Typically, the primer and pretreatment are applied as an aqueous or solvent-based mixture and reacted to form a film-like coating. They are typically not applied as part of an extrusion or coating process, but require treatment followed by drying and evaporation of the solvent. In addition, the laminate is visible as a distinct layer, while the primer and pretreatment do not result in a continuous film or phase. The primer and pretreatment do not result in a continuous phase on the mesh substrate because the viscosity is too low. The laminate is also formed from a self-sealing high molecular weight polymer having a definable mechanical strength.

In another embodiment of an abrasive article according to the present disclosure, the abrasive layer may comprise abrasive particles dispersed in a binder (in some embodiments, a phenolic resin layer). Referring now to fig. 8B, an abrasive article 900 has a backing 910, a laminate 920 secured to a major surface 915 of the backing 910, and an abrasive layer 930 secured to the laminate 920. Abrasive layer 930 includes abrasive particles 960 dispersed in a binder 940 (in some embodiments, a phenolic resin layer). In making such coated abrasive articles, a slurry comprising a binder precursor (in some embodiments, a phenolic resin) and abrasive particles is typically applied to a major surface of a backing, and the binder precursor is then at least partially cured. In one embodiment, the backing 910 is pretreated, for example, by a primer, such as a backsize layer, a presize layer, a tie layer, an impregnant, and/or a sub-size treatment.

In another embodiment, an abrasive article according to the present disclosure may comprise a structured abrasive article. Referring now to fig. 8C, structured abrasive article 1000 has backing 1010, laminate 1020 secured to major surface 1015 of backing 1010, and abrasive layer 1030 secured to primer layer 1020. Abrasive layer 1030 comprises a plurality of precisely shaped abrasive composites 1055. The abrasive composites comprise abrasive particles 1060 dispersed in a binder 1050. In one embodiment, the backing 1010 is pretreated, for example, by a primer, such as a backsize layer, a presize layer, a tie layer, an impregnant, and/or a sub-size treatment.

In making such abrasive articles, a slurry comprising a binder precursor (in some embodiments, a phenolic resin) and abrasive particles may be applied to a tool having a plurality of precisely shaped cavities therein. The slurry is then at least partially polymerized and attached to the primer layer by, for example, polymerization of the adhesive or slurry. The abrasive composites may have a variety of shapes including, for example, those selected from the group consisting of cubic, block-like, cylindrical, prismatic, pyramidal, truncated pyramidal, conical, truncated conical, cruciform, and hemispherical.

Fig. 9A and 9B illustrate an exemplary backing of an abrasive article according to an embodiment of the invention. The backing 1100 comprises a backing material 1130 having a laminate layer 1120. The backing material 1130 may also be pre-treated with a primer solution or layer prior to application of the laminate layers.

The abrasive articles of the various embodiments described herein include a backing substrate 1100. Backing substrate 1100 may be constructed from any of a variety of materials known in the art for making coated abrasive articles. For example, the backing substrate may be any of a fabric, an open weave fabric, a knit fabric, a porous fabric, a loop material, an unsealed fabric, an open or closed cell foam, a nonwoven fabric, a spun fiber, a film, a perforated film, or any other suitable backing material. The fabric backing may comprise a cloth (e.g., a cloth made of fibers or yarns comprising polyester, nylon, silk, cotton, and/or rayon, which may be woven, knitted, or stitch-bonded) or a scrim. Many of these materials may have uneven or rough surfaces. Applying the laminate to the backing material prior to applying the make coat can result in a more continuous, flatter, and smoother surface of the abrasive coating than would be useful without the laminate.

A suitable backing substrate 1100 needs to meet the criteria for abrasive applications. For example, the backing 1100 may require a particular stiffness and/or weight depending on the application. However, all backings need to have high adhesion to the primer resin. In addition, the backing should be smooth and flat to promote adhesion of the abrasive particles and reduce shelling.

Ideally, the backing substrate 1100 should also be a low cost material. Several potential low cost backing candidates, such as those with open or porous structures that are not easily sealed or have low adhesion to the primer resin, are typically discarded as potential backing materials. However, the application of the laminate can improve the adhesion, smoothness and flatness of such backing candidates.

In addition to improving the suitability of the backing material 1100, the laminate may also provide additional functions (such as anti-static or anti-fill functions).

Coated abrasive articles (such as those described herein) can be formed in a variety of ways, but typically involve coating a backing with one or more layers of material.

FIG. 10 illustrates a method for making a coated abrasive article according to one embodiment of the present invention.

In step 1210, a backing is provided. The backing may be flexible or rigid in nature. For example, the flexible backing may include a cloth (e.g., a cloth made of fibers or yarns including polyester, nylon, silk, cotton, and/or rayon, which may be woven, knitted, or stitch-bonded) and a scrim. The flexible backing may have a rough surface and may not be flat. The backing may undergo a pretreatment, such as a plasma pretreatment 1212 or a corona pretreatment 1214. Additionally, the backing may undergo the application of another pre-treatment 1216, such as the application of a backsize layer, a presize layer, a tie layer, a saturant, and/or a sub-size treatment.

In some embodiments of the articles, processes, and methods of the present disclosure, the polyester film backing comprises polyethylene terephthalate (PET). In some embodiments, the polyester film backing has a uniform composition throughout its thickness. In other embodiments, PET or any of the above polyesters may be included in a layer of the multilayer film backing. In these cases, the polyester layer will be in contact with the laminate layer.

Abrasive articles according to and/or made by the methods of the present disclosure include a polyester backing. For abrasive articles, the polyester backing may be the film backing described above. In addition to the dense integral film backing, fibrous backings may also be used in the abrasive articles described herein. In some embodiments, the polyester backing is a nonwoven. Nonwoven abrasive articles, such as spunbond backings, typically comprise an open, porous lofty polymeric filament structure with abrasive particles distributed throughout the structure and adhesively bonded in the structure by an organic binder, which in some embodiments is a phenolic resin as described above in any of the embodiments. Examples of filaments include polyester fibers made from any of the polyesters described above in connection with the polyester film backing.

Nonwoven abrasives according to the present disclosure include nonwoven webs suitable for use as abrasives. The term "nonwoven" refers to a material having a structure of individual fibers or filaments which are interlaid, but not in an identifiable manner, such as in a knitted fabric. Typically, the nonwoven web comprises an entangled fibrous web. The fibers may include continuous fibers, staple fibers, or a combination thereof. For example, the nonwoven web may include staple fibers having a length of at least about 20mm, at least about 30mm, or at least about 40mm, and less than about 110mm, less than about 85mm, or less than about 65mm, although shorter and longer fibers (e.g., continuous filaments) may also be used. The fibers can have a fineness or linear density of at least about 1.7 decitex (dtex, i.e., grams/10000 meters), at least about 6dtex, or at least about 17dtex, and less than about 560dtex, less than about 280dtex, or less than about 120dtex, although fibers with lesser and/or greater linear densities may also be useful. Mixtures of fibers having different linear densities may be used, for example, to provide abrasive articles that will produce a particularly preferred surface finish when in use. If a carded or air-laid nonwoven is used, the filaments may have a much larger diameter, for example, a diameter of at most 2mm or more. These fibers may be drawn and crimped, but may also be continuous filaments, such as those formed by an extrusion process (e.g., spunbond fibers). Combinations of fibers may also be used.

Nonwoven webs may be made, for example, by conventional air-laying, carding, stitch-bonding, spunbonding, wet-laying, and/or meltblowing processes. Airlaid nonwoven webs can be prepared using equipment such as, for example, equipment commercially available from RANDO Machine Company, macheon, New York, under the trade designation "RANDO WEBBER". Additional details regarding nonwoven abrasive articles, abrasive wheels, and methods for their manufacture can be found, for example, in U.S. Pat. No. 2,958,593(Hoover et al), U.S. Pat. No. 5,591,239(Larson et al); U.S. patent 6,017,831(Beardsley et al); and publication 2006/0041065 a1(Barber, Jr.).

In a polyester film backing useful in practicing some aspects of the present disclosure, the film backing will be considered monolithic (i.e., having a substantially uniform film composition) and not fibrous. Specifically, the film backing is not a nonwoven material. The polyester film backing may be described as a dense film rather than an open, lofty fibrous web.

Generally, the polyester film backings useful in practicing aspects of the present disclosure have a Gurley porosity of greater than 50 seconds when measured using a Gurley fabric air permeability tester (available from Teledyne Gurley, inc., Troy, n.y.)) according to FTMS No. 191, method 5452(12/31/68) (as set forth in the Wellington s Handbook of Industrial Textiles, Wellington s Handbook, edited by e.r. kaswell,1963, mentioned on page 575). The Gurley fabric air permeability tester measures the amount of time (in seconds) required for 100 cubic centimeters of air to pass through the backing material.

Polyester film backings that may be used to practice some aspects of the present disclosure may have a variety of thicknesses. In some embodiments, the polyester film backing has a thickness in a range from 1 micron to 500 microns, from 10 microns to 350 microns, from 25 microns to 250 microns, or from 35 microns to 200 microns.

Polyester film backings useful in the practice of the present disclosure may be uniaxially or biaxially oriented. Orientation of the film at temperatures above its glass transition temperature can be used to enhance at least one of the stiffness, modulus, or creep resistance of the film. Orientation may conveniently be carried out by conventional methods such as mechanical stretching (drawing) or tubular expansion with hot air or gas. Examples of useful stretch ratios in the machine direction, the transverse direction, or both the machine and transverse directions are in the range of 2.5 to 6 times. Greater stretch ratios (e.g., up to about 8 times) may also be useful if the film is oriented in only one direction. For a biaxially oriented film backing, the film may be stretched equally in the machine and transverse directions, or not equally in the machine and transverse directions.

In step 1220, a laminate is applied to the backing. In one embodiment, the laminate may be applied as a film. For example, it may be applied to the backing as a blown melt film 1222. In another embodiment, the laminate is extruded onto the backing 1224. Extrusion may include coextrusion of the laminate with the backing as well as extrusion of the laminate layer onto the existing backing. Other methods of application are also contemplated.

As indicated in block 1232, the laminate may result in the changed characteristics of the backing (once applied). For example, the laminate may increase the stiffness of the backing. In another example, the laminate may increase the smoothness and/or flatness of the backing. The laminate may also provide functionality such as anti-fill properties (as indicated in block 1234) or anti-static properties (as indicated in block 1236). Anti-filling and anti-static properties are achieved by increasing the electrical conductivity of the backing, which is achieved by using conductive materials or conductive additives for the laminate. The laminate may also promote adhesion between the make resin and the backing, as indicated in block 1238. The laminate may also provide other benefits, directly or indirectly, as indicated in block 1242. For example, the increased flatness of the laminate backing may reduce shelling of the abrasive particles during use.

In step 1230, a primer coating may be applied. In some embodiments, the primer coating is applied under conditions sufficient to cause the laminate layers to reopen to form voids, as described with respect to fig. 1-6. Applying the primer coating may also include a curing step to allow the primer coating to cure.

The make coat and size coat in the abrasive article of the present disclosure may be made of the same or different materials in any of their embodiments. Examples of such materials include amino resins, alkylated urea-formaldehyde resins, melamine-formaldehyde resins, and alkylated benzoguanamine-formaldehyde resins, acrylate resins (including acrylates and methacrylates) such as vinyl acrylate, acrylate-modified epoxy resins, acrylate-modified polyurethanes, acrylated polyesters, acrylated acrylic resins, acrylated polyethers, vinyl ethers, acrylated oils and acrylated silicones, alkyd resins such as urethane alkyd resins, polyester resins, reactive urethane resins, epoxy resins such as bisphenol epoxy resins, isocyanates, isocyanurates, polysiloxane resins (including alkylalkoxysilane resins), reactive vinyl resins, phenolic resins (resols and novolaks), and phenolic/latex resins. The resin may be provided as a monomer, oligomer, polymer, or combination thereof. The primer layer improves adhesion between the polyester backing and the make coat. In some embodiments, the make layer is an alkylated urea-formaldehyde resin, and the size layer may be made of any of the resins described above. In some embodiments, the make layer is a phenolic resin layer as described above in any of its embodiments, and the size layer may be made of any of the resins described above. In some embodiments, both the make layer and the size layer are made of a phenolic resin that can be combined with a latex (including any of the latexes described above) in any of the ratios described above.

Suitable phenolic resins are typically formed by the condensation of a phenol or alkylated phenol (e.g., cresol) and formaldehyde and are typically classified as resoles or novolaks. The novolac phenolic resin is acid catalyzed and has a formaldehyde to phenol molar ratio of less than 1: 1. Resol/resol phenolic resins may be catalyzed with a basic catalyst and have a formaldehyde to phenol molar ratio of greater than or equal to one, typically between 1.0 and 3.0, so that pendant methylol groups are present. Suitable basic catalysts for catalyzing the reaction between the aldehyde and phenol components of the resole resin include sodium hydroxide, barium hydroxide, potassium hydroxide, calcium hydroxide, organic amines, and sodium carbonate, all as a catalyst solution dissolved in water.

The resole is typically coated as a solution with water and/or an organic solvent (e.g., an alcohol). Typically, the solution comprises solids from about 70 wt% to about 85 wt%, although other concentrations may be used. If the solids content is very low, more energy is required to remove the water and/or solvent. If the solids content is very high, the viscosity of the resulting phenolic resin is too high, which often leads to processing problems.

Phenolic resins are well known and readily available from commercial sources. Examples of commercially available resoles that may be used in the practice of the present disclosure include those sold under the tradename VARCUM (e.g., 29217, 29306, 29318, 29338, 29353) by Durez Corporation (Durez Corporation); those sold under the trade name aerofen (e.g., aerofen 295) by Ashland Chemical company of barton, Florida, usa; and those sold under the trade name PHENOLITE (e.g., PHENOLITE TD-2207) by South of the river Chemical limited, Seoul, South Korea. The uncured or partially cured resin composition 240A converted into the cured resin composition 240 may comprise additional components including polyurethane dispersions, such as aliphatic and/or aromatic polyurethane dispersions. For example, the polyurethane dispersion may comprise a polycarbonate polyurethane, a polyester polyurethane, or a polyether polyurethane. The polyurethane may comprise a homopolymer or a copolymer.

Examples of commercially available polyurethane dispersions include aqueous aliphatic polyurethane emulsions available as NEOREZ R-960, NEOREZ R-966, NEOREZ R-967, NEOREZ R-9036, and NEOREZ R-9699 from Dismantane Resins Inc., Wilmington, Massachusetts, Wis.A.; aqueous anionic polyurethane dispersions available as ESSENTIAL CC4520, ESSENTIAL CC4560, ESSENTIAL R4100 and ESSENTIAL R4188 from basic Industries, morton, Wisconsin (Essential Industries, inc., Merton, Wisconsin); polyester polyurethane dispersions available as SANCURE 843, SANCURE 898, and SANCURE 12929 from Lubrizol, Inc (Cleveland, Ohio); aqueous aliphatic self-crosslinking polyurethane dispersions available as TURBOST 2025 from Lubrizol, Inc.; and a cosolvent free aqueous anionic aliphatic self-crosslinking polyurethane dispersion available under the trade designation BAYHYDROL PR240 from Bayer Material Science, LLC (Pittsburgh, Pennsylvania), Pittsburgh, pa.

Additional suitable commercially available aqueous polyurethane dispersions include:

1) alberdingk U6150, a solvent-free aliphatic polycarbonate polyurethane dispersion, available from Alberdingk Boley GmbH, Krefeld, Germany, of Alberdingk, Edenberg Germany, having a viscosity of 50 mPa.s-500 mPa.s (according to ISO1652, Brookfield RVT spindle 1/rpm 20/factor 5), an elongation at break of about 200% and a Koenig hardness after curing of about 65s-70 s;

2) albedingk U6800, an aqueous, solvent-free, colloidal low viscosity dispersion of an aliphatic polycarbonate polyurethane free of free isocyanate groups, available from albedingkeyard GmbH, Krefeld, Germany, having a viscosity of about 20 mPa-s to 200 mPa-s (according to ISO 2555, Brookfield RVT spindle 1/rpm 50/factor 2), an elongation at break of about 500% and a Koenig hardness after curing of about 45 s;

3) alberdingk U6100, an aqueous, colloidal, anionic, low viscosity dispersion of an aliphatic polyester-polyurethane free of free isocyanate groups, available from Alberdingk Boley GmbH, Krefeld, Germany, of Klefield, having a viscosity of about 20 mPa.s to 200 mPa.s (according to ISO1652, Brookfield RVT spindle 1/rpm 50/factor 2), an elongation at break of about 300% and a Koenig hardness after curing of about 50 s;

4) alberdingk U9800, a solventless aliphatic polyester polyurethane dispersion available from Alberdingk Boley Germany ltd (Alberdingk Boley GmbH, Krefeld, Germany), having a viscosity of about 20 mPa-s to 200 mPa-s (according to ISO1652, Brookfield RVT spindle 1/rpm 20/factor 5), and an elongation at break of about 20% to 50% and a Koenig hardness after curing of about 100s to 130 s; and

5) adiprene BL 16-liquid polyurethane elastomer with blocked isocyanate cure sites available from Chemtura, Middlebury, Connecticut, Chemtura, midlebury.

Optional additives for the polyurethane dispersion, and generally for the curable composition, including rheology modifiers, defoamers, water-based latexes, and crosslinkers can be added to the aqueous polyurethane dispersion. Suitable crosslinking agents include, for example, polyfunctional aziridines, methoxy methylolated melamines, urea resins, carbodiimides, polyisocyanates, and blocked isocyanates. Additional water may also be added to dilute the formulation of the aqueous polyurethane dispersion, phenolic resin, or combination thereof. The curable composition may be made, for example, from an aqueous polyurethane dispersion and a water-based latex.

The aqueous polyurethane dispersion comprises less than about 20%, 10%, 5%, or 2% organic solvent. In a particular embodiment, the aqueous polyurethane dispersion is substantially free of organic solvents. In some embodiments, it has been found that the aqueous polyurethane dispersion comprises at least about 7%, 15%, or 20% solids, and no greater than about 50% or 60% solids. The aqueous polyurethane dispersion may contain no more than about 80%, 85%, or 93% water. In some embodiments, it has been found that aqueous polyurethane dispersions form films having a Koenig hardness of at least about 30 seconds and not greater than about 200 seconds when measured according to ASTM 4366-16. Further, in some embodiments, it has been found that the surface tension of the aqueous polyurethane dispersion can be at least about 50% and not greater than about 300% of the surface tension of water. And in some embodiments, the aqueous polyurethane dispersion may have a viscosity of at least about 10mPa s to no greater than about 600mPa s, or at least about 70%, 80%, or 90% and no greater than about 600%, 500%, or 400% of the water viscosity.

Further, in some embodiments, the aqueous polyurethane dispersion can comprise at least about 100 parts per million (ppm), 1000ppm, or even at least about 10000ppm dimethylolpropionic acid. For example, optional additives (including rheology modifiers, defoamers, and crosslinkers) can be added to the aqueous polyurethane dispersion. Suitable crosslinking agents include, for example, polyfunctional aziridines, methoxy methylolated melamines, urea resins, carbodiimides, polyisocyanates, and blocked isocyanates. Additional water can be added to reduce the viscosity of the aqueous polyurethane dispersion. Likewise, the addition of up to 10 weight percent of an organic solvent (e.g., propyl methyl ether or isopropyl alcohol) to the aqueous polyurethane dispersion can be used to reduce the viscosity and/or improve the miscibility of the ingredients.

The dispersed polyurethane may comprise at least one polycarbonate segment, but this is not a requirement.

The phenolic resin and aqueous polyurethane dispersion components are mixed in a solids weight ratio of 91 to 99 weight percent phenolic resin to 9 to 1 weight percent polyurethane. In some embodiments, the phenolic resin and aqueous polyurethane dispersion components are mixed in a solids weight ratio of 56 to 91 weight percent phenolic resin to 44 to 9 weight percent polyurethane. In some embodiments, the phenolic resin and aqueous polyurethane dispersion components are mixed in a solids weight ratio of 62 to 91 weight percent phenolic resin to 38 to 9 weight percent polyurethane. In some embodiments, the phenolic resin and aqueous polyurethane dispersion components are mixed in a solids weight ratio of 69 to 91 weight percent phenolic resin to 31 to 9 weight percent polyurethane. In some embodiments, the phenolic resin and aqueous polyurethane dispersion components are mixed in a solids weight ratio of 56 to 83 weight percent phenolic resin to 44 to 17 weight percent polyurethane. In some embodiments, the phenolic resin and aqueous polyurethane dispersion components are mixed in a solids weight ratio of 56 to 76 weight percent phenolic resin to 44 to 24 weight percent polyurethane. In some embodiments, the phenolic resin and aqueous polyurethane dispersion components are mixed in a solids weight ratio of 56 to 69 weight percent phenolic resin to 44 to 31 weight percent polyurethane.

The curable compositions of the various embodiments described herein may also include any of a variety of additives. Such additives may be homogeneous or heterogeneous with one or more of the components of the composition. The heterogeneous additive may be discrete (e.g., particulate) or continuous in nature.

Such additives may include, for example, surfactants (e.g., defoamers such as ethoxylated nonionic surfactants such as DYNOL 604), pigments (e.g., carbon BLACK pigments such as C-SERIES BLACK 7LCD4115), fillers (e.g., silica Cabosil M5), synthetic waxes (e.g., synthetic paraffin MP22), stabilizers, plasticizers, tackifiers, flow control agents, cure rate retarders, adhesion promoters (e.g., silanes such as (3-glycidoxypropyl) trimethoxysilane (GPTMS) and titanates), adjuvants, impact modifiers, expandable microspheres, thermally conductive particles, electrically conductive particles, and the like, such as silica, glass, clay, talc, colorants, glass beads or glass bubbles, and antioxidants to, for example, reduce the weight and/or cost of the structural layer composition, adjust viscosity, and/or to provide additional reinforcement or to the thermal conductivity of the compositions and articles used in the provided methods Modified or such that a more rapid or uniform cure can be achieved.

In some embodiments, the curable composition may comprise one or more fibrous reinforcing materials. The use of fibrous reinforcement can provide an abrasive layer with improved cold flow characteristics, limited stretchability, and enhanced strength. Preferably, the one or more fibrous reinforcing materials may have a degree of porosity that enables the photoinitiator, when present, to be dispersed throughout the material, to be activated by UV light and to cure properly without the need for heating.

The one or more fibrous reinforcing materials may comprise one or more fibrous webs including, but not limited to, woven fabrics, non-woven fabrics, knitted fabrics, and unidirectional arrays of fibers. The one or more fibrous reinforcing materials may comprise a nonwoven fabric, such as a scrim.

The material used to make the one or more fibrous reinforcing materials may include any fiber-forming material capable of being formed into one of the webs described above. Suitable fiber-forming materials include, but are not limited to, polymeric materials such as polyesters, polyolefins, and aramids; organic materials such as wood pulp and cotton; inorganic materials such as glass, carbon, and ceramics; a coated fiber having a core component (e.g., any of the above fibers) and a coating thereon; and combinations thereof.

Further options and advantages of fiber reinforced materials are described in U.S. patent publication 2002/0182955(Weglewski et al).

In step 1240, abrasive particles are adhered. In some embodiments, the abrasive particles are applied at the same time as the make coat resin is applied, such that the abrasive particles are embedded within the make coat.

A variety of abrasive particles may be utilized in the various embodiments described herein. The particular type (e.g., size, shape, chemical composition) of abrasive particles is not considered to be particularly important for abrasive articles, so long as at least a portion of the abrasive particles are suitable for the intended end-use application. Suitable abrasive particles may be formed from, for example, cubic boron nitride, zirconia, alumina, silicon carbide, and diamond.

The abrasive particles can be provided in a variety of sizes, shapes, and distributions, including, for example, random or comminuted shapes, regular (e.g., symmetrical) distributions, such as square, star, or hexagonal distributions, and irregular (e.g., asymmetrical) distributions.

The abrasive article may comprise a mixture of abrasive particles that are inclined on the backing (i.e., stand up and extend outward from the backing) and abrasive particles that lie flat on their sides (i.e., they do not stand up and extend outward from the backing).

The abrasive article may comprise a mixture of different types of abrasive particles. For example, the abrasive article may include a mixture of plate-like and non-plate-like particles, crushed, agglomerated, and shaped particles (which may be discrete abrasive particles that do not include a binder or agglomerate abrasive particles that include a binder), conventional non-shaped and non-plate-like abrasive particles (e.g., filler material), and abrasive particles of different sizes.

Examples of suitable shaped abrasive particles can be found, for example, in U.S. Pat. Nos. 5,201,916(Berg) and 8,142,531(Adefris et al). Materials from which the shaped abrasive particles can be formed include alpha alumina. The alpha alumina shaped abrasive particles can be made from a dispersion of alumina monohydrate that is gelled, molded, dry set, calcined, and sintered according to techniques known in the art.

Examples of suitable shaped abrasive particles can also be found in published U.S. application 2015/0267097, the contents of which are incorporated herein by reference. Published U.S. application 2015/0267097 generally describes abrasive particles comprising alpha alumina having an average grain size of 0.8 to 8 microns and an apparent density of at least 92% of the true density. Each shaped abrasive particle may have a respective surface including a plurality of smooth sides forming at least four vertices.

U.S. patent 8,034,137(Erickson et al) describes alumina abrasive particles that have been formed into a particular shape and then comminuted to form shards that retain a portion of their original shape characteristics. In some embodiments, the shaped alpha alumina particles are precisely-shaped particles (i.e., the particles have a shape determined, at least in part, by the shape of the cavities in the production tool used to make them). Details regarding such shaped abrasive particles and their methods of preparation can be found, for example, in U.S. Pat. No. 8,142,531 (adegris et al); 8,142,891(Culler et al); and 8,142,532(Erickson et al); and U.S. patent application publications 2012/0227333 (adegris et al), 2013/0040537(Schwabel et al), and 2013/0125477 (adegris).

Examples of suitable crushed abrasive particles include crushed abrasive particles comprising: fused aluminum oxide, heat treated aluminum oxide, white fused aluminum oxide, ceramic aluminum oxide materials such as those commercially available from 3M Company (st. paul, Minnesota) of st paul, mn as 3MCERAMIC ABRASIVE GRAIN, brown aluminum oxide, blue aluminum oxide, silicon carbide (including green silicon carbide), titanium diboride, boron carbide, tungsten carbide, titanium carbide, diamond, cubic boron nitride, garnet, fused alumina zirconia, iron oxide, chromium oxide, zirconia, titanium dioxide, tin oxide, quartz, feldspar, flint, emery, sol-gel derived ceramics (e.g., alpha alumina), and combinations thereof. Additional examples include crushed abrasive composites of abrasive particles (which may or may not be plate-like) in a binder matrix, such as those described in U.S. Pat. No. 5,152,917(Pieper et al).

Examples of sol-gel derived abrasive particles from which the crushed abrasive particles can be isolated and methods for their preparation are found in U.S. patent 4,314,827 (leithiser et al); 4,623,364(Cottringer et al), 4,744,802(Schwabel), 4,770,671(Monroe et al), and 4,881,951(Monroe et al). It is also contemplated that the crushed abrasive particles may comprise abrasive agglomerates such as those described in U.S. Pat. No. 4,652,275(Bloecher et al) or U.S. Pat. No. 4,799,939(Bloecher et al).

The crushed abrasive particles include ceramic crushed abrasive particles, such as sol-gel derived polycrystalline alpha alumina particles. Ceramic crushed abrasive particles comprised of crystallites of alpha alumina, magnesium aluminate spinel, and rare earth hexaaluminate can be prepared using sol-gel alpha alumina particle precursors according to, for example, the methods described in U.S. patent 5,213,591(Celikkaya et al) and U.S. published patent applications 2009/0165394a1(Culler et al) and 2009/0169816a1(Erickson et al).

Additional details regarding the process of making sol-gel derived abrasive particles can be found, for example, in U.S. patent 4,314,827 (leithiser); 5,152,917(Pieper et al), 5,435,816(Spurgeon et al), 5,672,097(Hoopman et al); 5,946,991(Hoopman et al); 5,975,987(Hoopman et Al) and 6,129,540(Hoopman et Al), and U.S. patent publication 2009/0165394Al (Culler et Al). Examples of suitable plate-like crushed abrasive particles can be found, for example, in us patent 4,848,041 (Kruschke).

The abrasive particles may be surface treated with a coupling agent (e.g., an organosilane coupling agent) or other physical treatment (e.g., iron oxide or titanium oxide) to enhance adhesion of the crushed abrasive particles to the binder.

In some embodiments, the abrasive layer comprises a mixture of particles comprising a plurality of shaped abrasive particles (e.g., precision-formed grain (PSG) mineral particles from 3M company (3M, st. paul, MN), st. paul, MN, described in more detail herein; not shown in fig. 1-3) and a plurality of abrasive particles 250, or simply shaped abrasive particles, all adhesively secured to the abrasive layer.

In some embodiments, the abrasive particles can be shaped abrasive particles. As used herein, the term "shaped abrasive particles" generally refers to abrasive particles having an at least partially replicated shape (e.g., shaped ceramic abrasive particles). Non-limiting examples of shaped abrasive particles are disclosed in published U.S. patent application 2013/0344786, which is incorporated by reference as if fully set forth herein. Non-limiting examples of shaped abrasive particles include shaped abrasive particles formed in a mold, such as described in U.S. patent RE 35,570; the set squares disclosed in U.S. Pat. Nos. 5,201,916 and 5,984,998, all of which are incorporated herein by reference as if fully set forth herein; or extruded elongated ceramic rods/filaments, typically of circular cross-section, produced by Saint-Gobain Abrasives (Saint-Gobain Abrasives), an example of which is disclosed in U.S. patent 5,372,620, which is incorporated by reference as if fully set forth herein. Shaped abrasive particles, as used herein, does not include randomly sized abrasive particles obtained by a mechanical crushing operation.

The shaped abrasive particles further comprise shaped abrasive particles. As used herein, the term "shaped abrasive particles" generally refers to abrasive particles in which at least a portion of the abrasive particles have a predetermined shape that is replicated from a mold cavity used to form the shaped precursor abrasive particles. Except in the case of abrasive shards (e.g., as described in U.S. patent publication No. US 2009/0169816), the shaped abrasive particles will typically have a predetermined geometry that substantially replicates the mold cavities used to form the shaped abrasive particles. Shaped abrasive particles, as used herein, does not include randomly sized abrasive particles obtained by a mechanical crushing operation.

Shaped abrasive particles also include precision-formed grain (PSG) mineral particles, such as those described in published U.S. patent application 2015/267097, which is incorporated by reference as if fully set forth herein.

Examples of suitable abrasive particles include, for example, fused aluminum oxide, heat treated aluminum oxide, white fused aluminum oxide, black silicon carbide, green silicon carbide, titanium diboride, boron carbide, silicon nitride, tungsten carbide, titanium carbide, diamond, cubic boron nitride, hexagonal boron nitride, garnet, fused alumina-zirconia, alumina-based sol-gel derived abrasive particles, silica, iron oxide, chromium oxide, ceria, zirconia, carbon dioxide, tin oxide, gamma alumina, and mixtures thereof. The alumina abrasive particles can comprise a metal oxide modifier. Diamond and cubic boron nitride abrasive particles may be monocrystalline or polycrystalline.

In some examples, the substantially monodisperse particle size of the shaped abrasive particles is from about 1 micron to about 5000 microns, from about 1 micron to about 2500 microns, from about 1 micron to about 1000 microns, from about 10 microns to about 5000 microns, from about 10 microns to about 2500 microns, from about 10 microns to about 1000 microns, from about 50 microns to about 5000 microns, from about 50 microns to about 2500 microns, from about 50 microns to about 1000 microns. As used herein, the term "substantially monodisperse particle size" is used to describe shaped abrasive particles having a substantially unchanged size. Thus, for example, when referring to shaped abrasive particles having a particle size of 100 microns (e.g., PSG mineral particles), greater than 90%, greater than 95%, or greater than 99% of the shaped abrasive particles will have particles with a maximum dimension of 100 microns.

In some embodiments, the abrasive particles can have a range or distribution of particle sizes. This distribution can be characterized by its median particle size. For example, the median particle size of the abrasive particles can be at least 0.001 microns, at least 0.005 microns, at least 0.01 microns, at least 0.015 microns, or at least 0.02 microns. In some embodiments, the median particle size of the abrasive particles may be up to 300 microns, up to 275 microns, up to 250 microns, up to 150 microns, or up to 100 microns. In some examples, the abrasive particles have a median particle size of about 1 micron to about 600 microns, about 1 micron to about 300 microns, about 1 micron to about 150 microns, about 10 microns to about 600 microns, about 10 microns to about 300 microns, about 10 microns to about 150 microns, about 50 microns to about 600 microns, about 50 microns to about 300 microns, about 50 microns to about 150 microns.

In some examples, the abrasive particles of the present disclosure can comprise shaped abrasive particles. The shaped abrasive particles can be present from 0.01 wt% to 100 wt%, from 0.1 wt% to 100 wt%, from 1 wt% to 100 wt%, from 10 wt% to 100 wt%, from 0.01 wt% to 90 wt%, from 0.1 wt% to 90 wt%, from 1 wt% to 90 wt%, from 10 wt% to 90 wt%, from 0.01 wt% to 75 wt%, from 0.1 wt% to 75 wt%, from 1 wt% to 75 wt%, from 10 wt% to 75 wt%, based on the total weight of the abrasive particles.

In some examples, the particle mixture includes about greater than 90% to about 99% by weight abrasive particles (e.g., about 91% to about 97%, about 92% to about 97%, about 95% to about 97%, or greater than about 90% to about 97%).

In some embodiments, the abrasive particles are at least partially embedded (e.g., by electrostatic coating) into the make layer precursor comprising a phenolic resin, and the make layer precursor is at least partially polymerized.

In step 1250, an additional coating, such as a size coat or supersize coat, is applied. Such additional coatings may provide additional functions such as lubrication or grinding aids. A size layer is then prepared by coating a size layer precursor comprising a second resin (which may be the same or different than the size layer precursor) over at least a portion of the make layer and abrasive particles, and at least partially curing the size layer precursor. The make and size layers may comprise any binder resin suitable for abrasive applications. In some embodiments, the make layer precursor may be partially polymerized prior to coating with the abrasive particles, and further polymerized at a later point in the manufacturing process. In some embodiments, a supersize layer may be applied to at least a portion of the size layer. In some aspects, the articles, processes, and methods of the present disclosure include a polyester film backing. Useful polyester films can be made from various types of thermoplastic polyester resins, including polyethylene terephthalate, polybutylene terephthalate, polyethylene 2, 6-naphthalate, and poly-1, 4-cyclohexylenedimethylene terephthalate. Polyester copolymers (e.g., polyethylene terephthalate/isophthalate, polyethylene terephthalate/adipate, polyethylene terephthalate/sebacate, polyethylene terephthalate/sulfoisophthalate, and polyethylene terephthalate/azelate) may also be useful.

In some embodiments, the abrasive articles of the various embodiments described herein include a size coat 510. See fig. 5. In some examples, the size layer comprises a cured product of a phenolic size composition. In other examples, the size layer comprises a diepoxide (e.g., 3, 4-epoxycyclohexylmethyl-3, 4-epoxycyclohexylcarboxylate from celluloid Chemical Industries, ltd., Tokyo, Japan); trifunctional acrylates (e.g., trimethylolpropane triacrylate, available as "SR 351" from Sartomer USA, LLC, Exton, PA, axton, PA, USA); acidic polyester dispersants (e.g., "BYK W-985", available from Bicke chemical Co., Ltd of Vissel, Germany (Byk-Chemie, GmbH, Wesel, Germany)); fillers (e.g., sodium-potassium aluminosilicate fillers available under the trade designation "MINEX 10" from Kary Company of Edison, Ill. (Cary Company, Addison, IL)); photoinitiators (e.g., triarylsulfonium hexafluoroantimonate/propylene carbonate photoinitiator, available under the trade designation "CYRACURE CPI 6976" from Dow Chemical Company, Midland, MI, usa); and a cured (e.g., photopolymerized) product of an alpha-hydroxy ketone photoinitiator (available under the trade designation "DAROCUR 1173" from BASF Corporation, Florham Park, NJ, Florham, inc.).

In some embodiments, the abrasive articles of the various embodiments described include a supersize layer 610. See fig. 6. Generally, the supersize layer is the outermost coating of the abrasive article and directly contacts the workpiece during the abrading operation. In some examples, the supersize layer is substantially transparent.

The term "substantially transparent" as used herein means that the majority or majority is at least about 30%, 40%, 50%, 60%, or at least about 70% or more transparent. In some examples, the measure of transparency of any given coating (e.g., supersize) described herein is the transmittance of the coating. In some examples, the supersize layer exhibits a transmittance of at least 5%, at least 20%, at least 40%, at least 50%, or at least 60% (e.g., about 40% to about 80%; about 50% to about 70%; about 40% to about 70%; or about 50% to about 70%) according to a transmittance test that measures about 98% transmittance of 500nm light through a 6 by 12 inch by about 1 mil-2 mil (15.24 by 30.48cm by 25.4-50.8 μm) transparent polyester film.

One component of the supersize layer may be a long chain fatty acid (e.g., C) ₁₂ -C ₂₂ Fatty acid, C ₁₄ -C ₁₈ Fatty acids and C ₁₆ -C ₂₀ Fatty acids). In some examples, the metal salt of a long chain fatty acid is a stearate (e.g., a salt of stearic acid). The conjugate base of stearic acid is C ₁₇ H ₃₅ COO-, also known as stearate anion. Useful stearates include, but are not limited to, calcium stearate, zinc stearate, and combinations thereof.

The metal salt of a long chain fatty acid may be present in an amount of at least 10 wt.%, at least 50 wt.%, at least 70 wt.%, at least 80 wt.%, or at least 90 wt.%, based on the normalized weight of the supersize layer (i.e., the average weight per unit surface area of the abrasive particles). The metal salt of the long chain fatty acid can be present in an amount of up to 100 wt.%, up to 99 wt.%, up to 98 wt.%, up to 97 wt.%, up to 95 wt.%, up to 90 wt.%, up to 80 wt.%, or up to 60 wt.% (e.g., about 10 wt.% to about 100 wt.%, about 30 wt.% to about 70 wt.%, about 50 wt.% to about 90 wt.%, or about 50 wt.% to about 100 wt.%) based on the normalized weight of the supersize layer.

Another component of the supersize layer is a polymeric binder, which in some examples enables the supersize layer to form a smooth and continuous film on the abrasive layer. In one example, the polymeric binder is a styrene acrylic polymeric binder. In some examples, the styrene acrylic polymer binder is an ammonium salt of a modified styrene acrylic polymer, such as, but not limited to

LMV 7051. The ammonium salt of the styrene acrylic polymer can have a weight average molecular weight (Mw) of, for example, at least 100,000g/mol, at least 150,000g/mol, at least 200,000g/mol, at least 250,000g/mol (e.g., about 100,000g/mol to about 2.5X 106 g/mol; about 100,000g/mol to about 500,000 g/mol; or about 250,000 to about 2.5X 106 g/mol).

The supersize layer may also have a grinding aid, defined as a particulate material, which when added to the abrasive article has a significant impact on the chemical and physical processes of abrading. In particular, it is believed that the grinding aid may: (1) reducing friction between the abrasive particles and the workpiece being abraded; (2) prevent the abrasive particles from "plugging", i.e., preventing the metal particles from being welded to the top of the abrasive particles; (3) reducing the temperature of the interface between the abrasive particles and the workpiece; (4) the grinding force is reduced; and/or (5) synergistic effects with the above mechanisms. Generally, the addition of a grinding aid can increase the useful life of the coated abrasive article. Grinding aids encompass a wide variety of different materials and can be inorganic or organic.

Although grinding aids are described herein as being used in the supersize layer, they may also be applied as part of the laminate layer.

Exemplary grinding aids can include inorganic halide salts, halogenated compounds and polymers, and organic and inorganic sulfur-containing materials. Exemplary grinding aids can be organic or inorganic and include waxes, halogenated organic compounds, e.g., chlorinated waxes such as naphthalene tetrachloride, naphthalene pentachloride, and polyvinyl chloride; halide salts such as sodium chloride, potassium cryolite, sodium cryolite, ammonium cryolite, potassium tetrafluoroborate, sodium tetrafluoroborate, silicon fluorides, potassium chloride, magnesium chloride; and metals and their alloys, such as tin, lead, bismuth, cobalt, antimony, cadmium, iron, and titanium. Examples of other grinding aids include sulfur, organic sulfur compounds, graphite and metal sulfides, organic and inorganic phosphate containing materials. Combinations of different grinding aids can be used.

Preferred grinding aids include halide salts, especially potassium tetrafluoroborate (KBF4), cryolite (Na3AlF6), and ammonium cryolite [ (NH4)3AlF6 ]. Other halide salts that may be used as grinding aids include sodium chloride, elpasolite, sodium tetrafluoroborate, silicon fluoride, potassium chloride, and magnesium chloride. Other preferred grinding aids are those in U.S. patent 5,269,821(Helmin et al), which describes grinding aid agglomerates composed of water soluble and water insoluble grinding aid particles. Other useful grinding aid agglomerates are those in which a plurality of grinding aid particles are bound together with a binder to form an agglomerate. Agglomerates of this type are described in us patent 5,498,268(Gagliardi et al).

Examples of halogenated polymers that can be used as grinding aids include: polyvinyl halides (e.g., polyvinyl chloride) and polyvinylidene halides, such as those disclosed in U.S. patent 3,616,580(Dewell et al); highly chlorinated paraffins such as those disclosed in U.S. patent 3,676,092 (Buell); fully chlorinated hydrocarbon resins such as those disclosed in U.S. patent 3,784,365 (casterta et al); and fluorocarbons such as polytetrafluoroethylene and polychlorotrifluoroethylene as disclosed in U.S. patent 3,869,834(Mullin et al).

Inorganic sulfur-containing materials useful as grinding aids include elemental sulfur, ferrous sulfide, copper sulfide, molybdenum sulfide, potassium sulfate, and the like, as variously disclosed in U.S. Pat. Nos. 3,833,346(Wirth), 3,868,232(Sioui et al), and 4,475,926 (Hickoy). Organic sulfur-containing materials (e.g., thiourea) useful in the present invention include those mentioned in U.S. patent 3,058,819 (Paulson).

The present disclosure also contemplates the use of a combination of different grinding aids, and in certain instances, this can produce a synergistic effect. The above-mentioned examples of grinding aids are intended as a representative description of grinding aids, and they are not intended to encompass all grinding aids.

The supersize layer may also include other components and/or additives such as abrasive particles, fillers, diluents, fibers, lubricants, wetting agents, surfactants, pigments, dyes, coupling agents, resin curing agents, plasticizers, antistatic agents, and suspending agents. Examples of fillers suitable for use in the present invention include: wood pulp, vermiculite, and combinations thereof; metal carbonates such as calcium carbonate (e.g., chalk, calcite, marl, travertine, marble and limestone), calcium magnesium carbonate, sodium carbonate and magnesium carbonate; silica such as amorphous silica, quartz, glass beads, glass bubbles, and glass fibers; silicates such as talc, clay (montmorillonite), feldspar, mica, calcium silicate, calcium metasilicate, sodium aluminosilicate, sodium silicate; metal sulfates such as calcium sulfate, barium sulfate, sodium aluminum sulfate, aluminum sulfate; gypsum; vermiculite; wood flour; aluminum trihydrate; metal oxides such as calcium oxide (lime), aluminum oxide, titanium dioxide, and metal sulfites such as calcium sulfite.

The minimum film-forming temperature, also known as the MFFT, is the lowest temperature at which the polymer coalesces on itself in a semi-dry state to form a continuous polymer film. In the context of the present disclosure, the polymer film may then serve as a binder for the remaining solids present in the supersize layer. In some examples, the styrene acrylic polymer binder (e.g., an ammonium salt of a styrene acrylic polymer) has a MFFT of up to 90 ℃, up to 80 ℃, up to 70 ℃, up to 65 ℃, or up to 60 ℃.

In some examples, the binder is dried at a relatively low temperature (e.g., at 70 ℃ or less). In some examples, the drying temperature is below the melting temperature of the metal salt of the long chain fatty acid component of the supersize layer. Drying the supersize layer using too high a temperature (e.g., a temperature above 80 ℃) is undesirable because it can cause brittleness and cracking in the backing, complicate web handling, and increase manufacturing costs. The binder composed of, for example, an ammonium salt of a styrene acrylic polymer allows the topstock layer to achieve better film formation at lower binder content and lower temperatures without the need for adding surfactants, such as

DPnP。

The polymeric binder may be present in an amount of at least 0.1 wt%, at least 1 wt%, or at least 3 wt%, based on the normalized weight of the supersize layer. The polymeric binder may be present in an amount up to 20 wt.%, up to 12 wt.%, up to 10 wt.%, or up to 8 wt.%, based on the normalized weight of the supersize layer. Advantageously, when an ammonium salt of the modified styrene acrylic copolymer is used as the binder, the haze associated with the stearate coating is significantly reduced.

The topcoats of the present disclosure optionally comprise clay particles dispersed in the topcoats. The clay particles, when present, may be homogeneously mixed with the metal salt of a long chain fatty acid, the polymeric binder, and other components of the apex composition. Clays can impart unique advantageous properties to the abrasive article, such as improved optical clarity and improved cutting performance. The inclusion of clay particles may also provide cutting performance for a longer period of time relative to the supersize layer in the absence of the clay additive.

The clay particles (when present) may be present in an amount of at least 0.01 wt%, at least 0.05 wt%, at least 0.1 wt%, at least 0.15 wt%, or at least 0.2 wt%, based on the normalized weight of the supersize layer. Additionally, the clay particles may be present in an amount up to 99 percent, up to 50 percent, up to 25 percent, up to 10 percent, or up to 5 percent, based on the normalized weight of the supersize layer.

The clay particles may comprise particles of any known clay material. Such clay materials include those located in the geological classes of montmorillonite, kaolin, illite, chlorite, serpentine, attapulgite, palygorskite, vermiculite, glauconite, sepiolite, and mixed layer clays. Montmorillonite specifically includes montmorillonite (e.g., sodium montmorillonite or calcium montmorillonite), bentonite, pyrophyllite, hectorite, saponite, sauconite, nontronite, talc, beidellite, and volkonskoite. The kaolin comprises kaolinite, dickite, nacrite, antigorite, anauxite, halloysite and chrysotile. Illites include muscovite, paragonite, phlogopite, and biotite. The chlorite may include, for example, chlorite-vermiculite, phyllite (penninite), heulandite, sycamite, pennine (pennine), and clinochlorite. The mixed layer clays can include nacrite and biotite vermiculite. Variations and isomorphic substitutions of these layered clay minerals may also be used.

As an optional additive, the grinding performance may be further enhanced by nanoparticles (i.e., nanoscale particles) that are mutually dispersed in the supersize layer (e.g., in the clay particles). Useful nanoparticles include, for example, nanoparticles of metal oxides such as zirconia, titania, silica, ceria, alumina, iron oxide, vanadia, zinc oxide, antimony oxide, tin oxide, and alumina silica. The nanoparticles have a median particle size of at least 1 nanometer, at least 1.5 nanometers, or at least 2 nanometers. The median particle size may be up to 200 nanometers, up to 150 nanometers, up to 100 nanometers, up to 50 nanometers, or up to 30 nanometers.

Other optional components of the apex composition include curing agents, surfactants, defoamers, biocides, and other particulate additives known in the art for use in apex compositions.

In some examples, the supersize layer may be formed by providing a supersize composition in which the components are dissolved or otherwise dispersed in a common solvent. In some examples, the solvent is water. After appropriate mixing, the supersize dispersion may be coated onto an underlying layer of the abrasive article and dried to provide a finished supersize layer. If present, the apex composition can be cured (e.g., hardened) thermally or by exposure to actinic radiation of a suitable wavelength to activate the curing agent.

The supersize composition may be applied to, for example, the abrasive layer using any known process. In some examples, the supersize composition is applied by spraying at a constant pressure to achieve a predetermined coat weight. Alternatively, a blade coating process may be used, where the coating thickness is controlled by the gap height of the blade coater.

Abrasive articles according to the present disclosure may be converted, for example, into belts, rolls (e.g., tape rolls), discs (e.g., porous discs), or sheets. They may be used manually or in combination with a machine such as a belt grinder. For belt applications, the two free ends of the abrasive sheet are joined together and spliced to form an endless belt.

As used herein, the term "about" can allow, for example, a degree of variability in the value or range, e.g., within 10%, within 5%, or within 1% of the stated value or limit of the range.

As used herein, unless otherwise specified herein, the term "substantially" refers to a majority or majority, such as at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more.

As used herein, unless otherwise specified herein, the term "substantially free" means a small fraction, or few, such as less than about 10%, 5%, 2%, 1%, 0.5%, 0.01%, 0.001%, or less than about 0.0001%, or less.

Values expressed as a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of "about 0.1% to about 5%" or "about 0.1% to 5%" should be interpreted to include not only about 0.1% to about 5%, but also include individual values (e.g., 1%, 2%, 3%, and 4%) and sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. Unless otherwise indicated, the expression "about X to Y" has the same meaning as "about X to about Y". Likewise, unless otherwise indicated, the expression "about X, Y or about Z" has the same meaning as "about X, about Y, or about Z".

In this document, the terms "a", "an" or "the" are used to include one or more than one unless the context clearly indicates otherwise. The term "or" is used to refer to a non-exclusive "or" unless otherwise indicated. The term "or" is used to refer to a non-exclusive "or" unless otherwise indicated. Any use of section headings is intended to aid in the understanding of the document and should not be construed as limiting. Further, information related to a section header may be presented within or outside of that particular section. Further, all publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as if individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference should be considered supplementary to that of the document; for irreconcilable inconsistencies, the usage of the document controls.

In the methods described herein, various steps may be performed in any order without departing from the principles of the invention, except when a time or sequence of operations is explicitly recited. Further, the specified steps can be performed concurrently unless explicit claim language implies that they are performed separately. For example, performing the claimed step of X and performing the claimed step of Y may be performed simultaneously in a single operation, and the resulting process would fall within the literal scope of the claimed process.

An abrasive article is disclosed. The article includes a backing substrate and a laminate joined to the backing substrate. The laminate comprises a hot melt polymer. The article includes a cured resin composition joined to the laminate opposite the backing substrate. The article also includes abrasive particles bonded to the cured resin composition.

The abrasive article may be implemented such that the laminate is at least partially wrapped around the strands to open the first and second void spaces.

The abrasive article may be implemented such that the laminate is joined to the backing substrate in the form of a continuous sheet, an extruded film, or a coating.

An abrasive article may be implemented such that the laminate is extruded onto the backing substrate.

The abrasive article can be implemented such that the substrate is treated by a priming treatment either before or after lamination.

The abrasive article can be implemented such that the priming treatment is one of: a backsize layer, a presize layer, a tie layer, a saturant, a subbing treatment, a plasma treatment, a corona treatment, an ultraviolet exposure, an electron beam exposure, a flame discharge, or combinations thereof.

An abrasive article can be implemented such that the fabric substrate has a first stiffness and a second stiffness after the laminate is joined to the fabric substrate, and wherein the second stiffness is equal to or higher than the first stiffness.

The abrasive article may be implemented such that the backing comprises a woven material.

The abrasive article can be implemented such that the backing comprises a nonwoven material.

The abrasive article may be implemented such that the backing comprises a perforated film.

An abrasive article may be implemented such that the backing substrate comprises a fabric comprising strands forming first void spaces between the strands, and wherein a plurality of second void spaces extend through the laminate and coincide with the first void spaces in the fabric substrate.

The abrasive article may be implemented such that the second void space is formed when the cured resin is joined to the laminate.

The abrasive article may be implemented such that the hot melt polymer comprises a polyester.

The abrasive article can be implemented such that the hot melt polymer comprises a polyamide, a polyester, a poly [ ethylene acrylic acid ] copolymer, a poly (ethylene-acrylate) copolymer, a poly (ethyl methyl acetate) copolymer, a polyolefin, polyurethane polyethylvinyl acetate, a polyethylene acrylate copolymer, an ethylene methacrylic acid copolymer, an acid modified ethylene terpolymer, an anhydride modified vinylacetate, a vinyl acetate polymer, or a blend thereof.

The abrasive article can be implemented such that the laminate comprises a material having a melting point between about 30 ℃ to about 220 ℃.

The abrasive article can be implemented such that the laminate comprises a material having a melting point between about 75 ℃ to about 115 ℃.

The abrasive article may be implemented such that the laminate comprises a material that has a melting temperature below the melting point or degradation temperature of the above-described coated resin, but high enough such that the laminate will not melt or wash away during resin curing and abrasive use.

An abrasive article can be implemented such that the backing substrate has a first surface roughness and a second surface roughness after the laminate is joined to the backing substrate, and wherein the second surface roughness is less than the first surface roughness.

An abrasive article can be implemented such that the laminate joined to the backing substrate has a surface roughness value of less than about 20 μm.

An abrasive article can be implemented such that the laminate joined to the backing substrate has a surface roughness value of less than about 10 μm.

The abrasive article can be implemented such that the laminate has a coat weight of between about 10gsm and about 200 gsm.

The abrasive article can be implemented such that the laminate has a coat weight of between about 15gsm and about 40 gsm.

The abrasive article can be implemented such that the laminate has a coat weight of between about 25gsm and about 35 gsm.

The abrasive article may be implemented such that the laminate substantially prevents the resin from penetrating to the backing substrate such that the resin does not directly contact the backing substrate.

The abrasive article can be implemented such that the abrasive particles comprise crushed abrasive particles, shaped abrasive particles, plate abrasive particles, shaped abrasive particles, or mixtures thereof.

The abrasive article can be implemented such that the abrasive particles comprise particles having similar sizes.

The abrasive article can be implemented such that it further includes a size coat applied over the abrasive particles.

The abrasive article may be implemented such that it further includes a supersize layer.

The abrasive article can be implemented such that the laminate has an anti-loading function.

The abrasive article can be implemented such that the laminate has an antistatic function.

The abrasive article may be implemented such that the laminate has an adhesion promoting function with respect to the backing and the resin composition.

The abrasive article may be implemented such that the laminate is configured to bond to a backing base material and a resin composition.

The abrasive article may be implemented such that the resin composition includes a novolac phenolic resin or a resole phenolic resin, an epoxy, a UF-primer reference.

A method of making a coated abrasive article is provided. The method includes providing a backing substrate. The method also includes applying a thermoplastic laminate. The method also includes applying a primer resin. The method also includes applying a plurality of abrasive particles.

The method may further comprise applying a size coat.

The method can also be implemented such that the backing substrate undergoes a priming treatment, wherein the priming treatment is one of: a backsize layer, a pre-size layer, a tie layer, a saturant, a subbing treatment, a plasma treatment, a corona treatment, an ultraviolet exposure, an electron beam exposure, or a flame discharge.

The method may further comprise applying the thermoplastic laminate, including applying the laminate in the form of a continuous sheet, a blown melt film, or an extrudate.

The method can also be implemented such that the laminate is coextruded with the backing substrate.

The method may also be implemented such that the backing substrate comprises: a woven substrate, a nonwoven substrate, a mesh substrate, a fabric substrate, a continuous material, or a perforated film.

The method may further include applying a thermoplastic laminate including applying the laminate at a coat weight of between about 10gsm and about 60 gsm.

The method may further include applying a thermoplastic laminate including applying the laminate at a coat weight of between about 15gsm and about 40 gsm.

The method may further include applying a thermoplastic laminate including applying the laminate at a coat weight of between about 15gsm and about 25 gsm.

The method can also be practiced such that after applying the laminate, the backing substrate has a roughness of less than about 20 μm.

The method can also be practiced such that after applying the laminate, the backing substrate has a roughness of less than about 20 μm.

The method can also be practiced such that the laminate has a coating thickness of between about 10 μm and about 50 μm.

The method can also be practiced such that the laminate has a coating thickness of between about 10 μm and about 20 μm.

The method may also be practiced such that the resin is a phenolic resin or resole.

The method can also be implemented such that the hot melt polymer comprises a polyester.

The method may also be practiced such that the hot melt polymer comprises a polyamide, an Ethylene and Acrylic Acid (EAA) copolymer, ethyl methyl acetate, or vinyl acetate.

The method can also be practiced such that the laminate comprises a material having a melting point between about 50 ℃ to about 150 ℃.

The method can also be practiced such that the laminate comprises a material having a melting point between about 80 ℃ to about 110 ℃.

Methods may also be implemented such that the backing substrate comprises a fabric comprising strands forming first void spaces between the strands, and wherein a plurality of second void spaces extend through the laminate and coincide with the first void spaces in the fabric substrate.

The method can also be practiced such that the second void space is formed when the resin is applied to the laminate.

The method may also be practiced such that the cured resin contacts substantially only the laminate such that the resin does not substantially contact the backing substrate.

The method can also be implemented such that the laminate has an anti-fill function.

The method can also be implemented such that the laminate has an antistatic function.

The method can also be implemented such that the laminate has an adhesion promoting function with respect to the backing and the resin composition.

Examples

The embodiments described herein are intended to be exemplary only and not predictive, and variations in manufacturing and testing procedures may produce different results. All quantitative values in the examples section are to be understood as approximations according to the commonly known tolerances involved in the procedures used. The foregoing detailed description and examples have been given for clarity of understanding only. They are not to be construed as unnecessarily limiting.

Unless otherwise indicated, all reagents were obtained or purchased from chemical suppliers such as Sigma Aldrich Company of st. All ratios are on a dry weight basis unless otherwise reported.

Preparation of extruded films

A 2 inch diameter laboratory extruder supplied from Bonnot co, Ohio having a length to diameter ratio (L/D) of 10 was used to extrude the polymer or polymer blend and fed to a casting die. The molten polymer film from the casting mold is cast onto the surface of a chill roll having a surface temperature in the range of 0 ℃ to 40 ℃. The film was cooled and wound as a film sample roll.

Example 1：

A Steamfast SF-680 digital steam press was used for sample lamination. The rig is preset in "silk" mode, with ceiling temperatures of 130-140 ℃ (measured by IR thermometer). A 120gsm (grams per square meter) mesh web (Sitip, Itay) with a loop fabric on one side was cut into 23cm x 28cm sheets and placed on the floor of a steam press with the loop face down. A pre-extruded 30gsm film consisting of 80% copolyester (HM4185, Bostik, MA) and 20% poly (ethylene acrylic acid) (PRIMACOR3330, Dow Chemical) was cut to the same size and aligned on top of the mesh. A paper release liner with a slightly larger dimension is placed on top to cover the film and the grid with the release face down. The top plate of the steam press is pushed down to close the gap until the web reaches the preset temperature. After the entire web was cooled to ambient temperature, the release liner was removed from the top surface to obtain a film laminate backing sample.

Fig. 17A shows the fabric backing before lamination and fig. 17B shows the fabric backing after lamination. Using the method described below and shown in fig. 18A and 18B, the surface roughness was measured to be 8.21 μm.

Example 2：

The steam press is preset in "wire" mode, with ceiling temperatures of 130-140 ℃ (measured by IR thermometer). 170gsm scrim (Milliken, SC) was cut into 23cm by 28cm sheets and placed on the floor of a steam press with the annulus down. A pre-extruded 165gsm film consisting of 80% copolyester (HM4185, Bostik, MA) and 20% poly (ethylene acrylic acid) (PRIMACOR3330, Dow Chemical) was cut to the same size and aligned on top of the mesh. A paper release liner with a slightly larger dimension is placed on top to cover the film and the grid with the release face down. The top plate of the steam press is pushed down to close the gap until the web reaches the preset temperature. After the entire web was cooled to ambient temperature, the release liner was removed from the top surface to obtain a film laminate backing sample. Fig. 17C shows the fabric backing before lamination and fig. 17D shows the fabric backing after lamination. As shown in fig. 18A and 18B, the surface roughness of the laminated sample and the original cloth was measured as 7.08 μm and 27.98 μm, respectively, using the method described below.

Example 3：

The steam press is preset in "wire" mode, with ceiling temperatures of 130-140 ℃ (measured by IR thermometer). A 330gsm satin-woven polyester cloth (Milliken, SC) was cut into 23cm x 28cm sheets and placed on the floor of a steam press with the annulus down. A pre-extruded 204gsm film consisting of 80% copolyester (HM4185, Bostik, MA) and 20% poly (ethylene acrylic acid) (PRIMACOR3330, Dow Chemical) was cut to the same size and aligned on top of the mesh. A paper release liner with a slightly larger dimension is placed on top to cover the film and the grid with the release face down. The top plate of the steam press is pushed down to close the gap until the web reaches the preset temperature. After the entire web was cooled to ambient temperature, the release liner was removed from the top surface to obtain a film laminate backing sample. Fig. 17E shows the fabric backing before lamination and fig. 17F shows the fabric backing after lamination. As shown in fig. 18A and 18B, the surface roughness of the laminated sample and the original cloth was measured as 6.93 μm and 23.85 μm, respectively, using the method described below.

Surface roughness measuring method：

The surface was scanned using a Keyence VKX1100 confocal 3D measurement microscope. The microscope has 2.5 times lenses and stitching 2 x 2, resulting in about 85mm ² The area of (a). The Sa and Sdr surface roughness/texture parameters as defined in ISO-21578 were obtained using Keyence VK series analyzer software, where Sa refers to the arithmetic mean height of the surface and Sdr refers to the development interface true ratio.

Claims (57)

1. An abrasive article comprising:

a backing substrate;

a laminate joined to the backing substrate, wherein the laminate comprises a hot melt polymer;

a cured resin composition joined to the laminate opposite the backing substrate;

abrasive particles bonded to the cured resin composition.

2. The abrasive article of claim 1, wherein the laminate is at least partially wrapped around a strand to leave open first and second void spaces.

3. The abrasive article of any one of claims 1 to 2, wherein the laminate is joined to the backing substrate in the form of a continuous sheet, an extruded film, or a coating.

4. The abrasive article of any one of claims 1 to 3, wherein the laminate is extruded onto the backing substrate.

5. The abrasive article of any one of claims 1 to 4, wherein the substrate is treated by a priming treatment before or after lamination.

6. The abrasive article of claim 5, wherein the priming treatment is one of: a backsize layer, a presize layer, a tie layer, a saturant, a subbing treatment, a plasma treatment, a corona treatment, an ultraviolet exposure, an electron beam exposure, a flame discharge, or combinations thereof.

7. The abrasive article of any one of claims 1 to 6, wherein fabric substrate has a first stiffness and a second stiffness after the laminate is joined to the fabric substrate, and wherein the second stiffness is equal to or higher than the first stiffness.

8. The abrasive article of any one of claims 1 to 7, wherein the backing comprises a woven material.

9. The abrasive article of any one of claims 1 to 8, wherein the backing comprises a nonwoven material.

10. The abrasive article of any one of claims 1 to 9, wherein the backing comprises a perforated film.

11. The abrasive article of any one of claims 1 to 10, wherein the backing substrate comprises a fabric comprising strands forming first void spaces between the strands, and wherein a plurality of second void spaces extend through the laminate and coincide with first void spaces in the fabric substrate.

12. The abrasive article of claim 11, wherein the second void space is formed when the cured resin is joined to the laminate.

13. The abrasive article of any one of claims 1 to 12, wherein the hot melt polymer comprises a polyester.

14. The abrasive article of any one of claims 1 to 13, wherein the hot melt polymer comprises a polyamide, a polyester, a poly [ ethylene acrylic acid ] copolymer, a poly (ethylene-acrylate) copolymer, a poly (ethyl methyl acetate) copolymer, a polyolefin, polyurethane polyethylvinyl acetate, a polyethylene acrylate copolymer, an ethylene methacrylic acid copolymer, an acid-modified ethylene terpolymer, an anhydride-modified vinyl acylate, a vinyl acetate polymer, or a blend thereof.

15. The abrasive article of claim 1, wherein the laminate comprises a material having a melting point between about 30 ℃ to about 220 ℃.

16. The abrasive article of claim 1, wherein the laminate comprises a material having a melting point between about 75 ℃ to about 115 ℃.

17. The abrasive article of claim 1 wherein the laminate comprises a material having a melting temperature below the melting or degradation temperature of the above-described coated resin, but sufficiently high that the laminate will not melt or wash away during resin curing and abrasive use.

18. The abrasive article of claim 1, wherein the backing substrate has a first surface roughness and a second surface roughness after the laminate is joined to the backing substrate, and wherein the second surface roughness is less than the first surface roughness.

19. The abrasive article of claim 1, wherein the laminate joined to the backing substrate has a surface roughness value of less than about 20 μ ι η.

20. The abrasive article of claim 1, wherein the laminate joined to the backing substrate has a surface roughness value of less than about 10 μ ι η.

21. The abrasive article of claim 1, wherein the laminate has a coat weight of between about 10gsm and about 200 gsm.

22. The abrasive article of claim 1, wherein the laminate has a coat weight of between about 15gsm and about 40 gsm.

23. The abrasive article of claim 1, wherein the laminate has a coat weight of between about 25gsm and about 35 gsm.

24. The abrasive article of claim 1, wherein the laminate substantially prevents the resin from penetrating to the backing substrate such that the resin does not directly contact the backing substrate.

25. The abrasive article of claim 1, wherein the abrasive particles comprise crushed abrasive particles, shaped abrasive particles, plate abrasive particles, shaped abrasive particles, or mixtures thereof.

26. The abrasive article of claim 25, wherein the abrasive particles comprise particles of similar size.

27. The abrasive article of claim 1, and further comprising a size coat applied over the abrasive particles.

28. The abrasive article of claim 27, and further comprising a supersize layer.

29. The abrasive article of claim 1, wherein the laminate has an anti-loading function.

30. The abrasive article of claim 1, wherein the laminate has an antistatic function.

31. The abrasive article of claim 1, wherein the laminate has an adhesion promoting function with respect to the backing and resin composition.

32. The abrasive article of claim 1, wherein the laminate is configured to bond to a backing base material and a resin composition.

33. The abrasive article of claim 31, wherein the resin composition comprises a novolac or resole phenolic resin, an epoxy, a UF-primer reference.

34. A method of making a coated abrasive article, the method comprising:

providing a backing substrate;

applying a thermoplastic laminate;

applying a primer resin;

a plurality of abrasive particles is applied.

35. The method of claim 34 and further comprising applying a size coat.

36. The method of any one of claims 34 to 35, wherein the backing substrate is subjected to a priming treatment, wherein the priming treatment is one of: a backsize layer, a pre-size layer, a tie layer, a saturant, a subbing treatment, a plasma treatment, a corona treatment, an ultraviolet exposure, an electron beam exposure, or a flame discharge.

37. The method of any one of claims 34 to 36, wherein applying the thermoplastic laminate comprises applying the laminate in the form of a continuous sheet, a blown melt film, or an extrudate.

38. The method of any one of claims 34 to 37, wherein the laminate is coextruded with the backing substrate.

39. The method of any one of claims 34 to 38, wherein the backing substrate comprises: a woven substrate, a nonwoven substrate, a mesh substrate, a fabric substrate, a continuous material, or a perforated film.

40. The method of any one of claims 34 to 39, wherein applying a thermoplastic laminate comprises applying the laminate at a coat weight of between about 10gsm and about 60 gsm.

41. The method of any one of claims 34 to 40, wherein applying a thermoplastic laminate comprises applying the laminate at a coat weight of between about 15gsm and about 40 gsm.

42. The method of any one of claims 34 to 41, wherein applying a thermoplastic laminate comprises applying the laminate at a coat weight of between about 15gsm and about 25 gsm.

43. The method of any one of claims 34 to 42, wherein the backing substrate has a roughness of less than about 20 μm after the laminate is applied.

44. The method of any one of claims 34 to 43, wherein the backing substrate has a roughness of less than about 20 μm after the laminate is applied.

45. The method of any one of claims 34 to 44, wherein the laminate has a coating thickness of between about 10 μm and about 50 μm.

46. The method of any one of claims 34 to 45, wherein the laminate has a coating thickness of between about 10 μm and about 20 μm.

47. A method according to any one of claims 34 to 46, wherein the resin is a phenolic resin or a resole.

48. The method of any one of claims 34 to 47, wherein the hot melt polymer comprises a polyester.

49. The method of any one of claims 34 to 48, wherein the hot melt polymer comprises a polyamide, an Ethylene and Acrylic Acid (EAA) copolymer, ethyl methyl acetate, or vinyl ethyl acetate.

50. The method of any one of claims 34 to 49, wherein the laminate comprises a material having a melting point between about 50 ℃ to about 150 ℃.

51. The method of any one of claims 34 to 50, wherein the laminate comprises a material having a melting point between about 80 ℃ to about 110 ℃.

52. The method of any one of claims 34 to 51, wherein the backing substrate comprises a fabric comprising strands forming first void spaces therebetween, and wherein a plurality of second void spaces extend through the laminate and coincide with first void spaces in the fabric substrate.

53. The method of claim 52, wherein the second void space is formed when the resin is applied to the laminate.

54. The method of any one of claims 34 to 53, wherein the cured resin contacts substantially only the laminate such that the resin does not substantially contact the backing substrate.

55. The method of any one of claims 34 to 54, wherein the laminate has an anti-fill function.

56. The method of any one of claims 34 to 55, wherein the laminate has an antistatic function.

57. The method of any one of claims 34 to 56, wherein the laminate has an adhesion promoting function with respect to the backing and resin composition.

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