CA2007510A1 - Intumescent flame retardant systems - Google Patents
Intumescent flame retardant systemsInfo
- Publication number
- CA2007510A1 CA2007510A1 CA 2007510 CA2007510A CA2007510A1 CA 2007510 A1 CA2007510 A1 CA 2007510A1 CA 2007510 CA2007510 CA 2007510 CA 2007510 A CA2007510 A CA 2007510A CA 2007510 A1 CA2007510 A1 CA 2007510A1
- Authority
- CA
- Canada
- Prior art keywords
- flame retardant
- weight
- percent
- additive
- melamine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
- C08K5/34—Heterocyclic compounds having nitrogen in the ring
- C08K5/3467—Heterocyclic compounds having nitrogen in the ring having more than two nitrogen atoms in the ring
- C08K5/3477—Six-membered rings
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/32—Phosphorus-containing compounds
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K21/00—Fireproofing materials
- C09K21/14—Macromolecular materials
Abstract
ABSTRACT
This invention is that of a flame retardant additive composition for polymers comprising an ammonium or amine phosphate (50 - 95%), a hydroxyalkyl isocyanurate (5 - 50%) and a minor amount of polytetrafluoroethylene (0.3 - 9%). Optionally, the flame retardant additive composition may contain as a fourth component, a blowing agent (5 - 40%) such as urea, melamine, glycine etc. Preferred components are ammonium polyphosphate, tris-(2-hydroxyethyl) isocyanurate and polytetrafluoroethylene.
The flame retardant additive composition may be used to impart flame retardancy to synthetic hydrocarbon polymers, in particular polypropylene and polyester - polyether copolymers wherein said additive is employed in an amount of about 5 to 50 percent based upon the total weight of polymer and additive.
This invention is that of a flame retardant additive composition for polymers comprising an ammonium or amine phosphate (50 - 95%), a hydroxyalkyl isocyanurate (5 - 50%) and a minor amount of polytetrafluoroethylene (0.3 - 9%). Optionally, the flame retardant additive composition may contain as a fourth component, a blowing agent (5 - 40%) such as urea, melamine, glycine etc. Preferred components are ammonium polyphosphate, tris-(2-hydroxyethyl) isocyanurate and polytetrafluoroethylene.
The flame retardant additive composition may be used to impart flame retardancy to synthetic hydrocarbon polymers, in particular polypropylene and polyester - polyether copolymers wherein said additive is employed in an amount of about 5 to 50 percent based upon the total weight of polymer and additive.
Description
~,r~ t.~.3 --- CROSS REFE~ENL~E: 'ro RELATED APP ICATIONS __ This application is a continuation-in-part of U.S. Patent Application Seriai No. 87,186 filed August 19, 19~7 now FIELD OF THE INVENTION
This invention is that of improved char forming fiame retardants:and flame retardant polymer compositions containing said char forming flame retardants.
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This invention is that of improved char forming fiame retardants:and flame retardant polymer compositions containing said char forming flame retardants.
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BAC~G RoUND OF TH E I NVENT I ON
~_ ___ Char forming or intumescent flame retardant compositions are well known in the paint, coating and plastic fields.
These systems qenerally consist of three components, an acid generating component, a char forming component and a blowing agent. A well known intumescent flame re~ardant is the ammoniu~
polyphosphate (APP)~dipentaerythritol (DPET)~elamine (ME) system.
The theory and background of such intumescent flame retardant systems is widely reported in the literature, see e.g., The Chemistry and Uses of Flame Reta~dants", John Lyons, p. 256 - 280, (1970) and "Intumescen~ Coating Systems, Their Development and Chemistry"t H. L. Vandersall, J. Fire &
~lammability, Vol. 2, p. 97, (April 1970).
V~ndersal' describ~s ti,~ comn,erciai use of the ammonium polyphosphate (acid generator), dipentaerythritol (char former) and melamine (blowing agent) system in the paint/coating area and U.S. Patent No. 3,810,862 describes the use of this APP/DPET/ME
system in plastics. U.S. Patent No. 4,198,493 describes a similar intumescent flame retardant system for use in paints and plastics in which the polyhydroxy component, dipentaerythritol is replaced by the polyhydroxy compoundl tris(2-hydroxyethyl)-isocyanurate.
Similarly, flame retardant polymer compositions based upon halogenated organic compounds, phosphorus containing organic compounds and halogenated organic compounds - antimony oxide mixtures are well known. The addition of such flame-retardant additives to polymers has the effect of reducing the physical properties of the polymer. Therefore, it has been the object of workers ~in this field to endeavor to obtain maximum flame ~3~
retardancy using the lowest amount of fla~e-retardant additive in both intumescent and halogen/ phosphorus organic compounds systems.
The 1ame retardancy of a polymer composition can be measured by the UL-94 tes~ method (Underwriters Laboratories Inc.) This test is well known and is incorporated herein by reference. Flame retardancy is rated V-0 (best), V-l, V-2 under the UL-94 test method which rates performance on the basis of time for the test specimen to stop burning in air and the presence or absence of a flame spreadinq drip from ~he test specimen.
In vie~ of the fact that the presence of dripping, flaming polymer droplets increase the rate of spread of a fire, efforts have been made to prod~ce flame retardant polymer compositions which do not exhibit this flame spreading tendency. These prior attemptS to prod~ c:, ;Jperior _ompositlons ~re based upon the halogenated or phos~horus-organic compound type flame retardant systems, perhaps because the intumescent type flame retardant systems are generally more drip retardant than these systems.
Examples of some of the reported flame retardant systems follow.
U.S. Patent 4,490,504 describes improved flame retardant composition sulfur-containing polycarbonates and fiberglass.
U.S. Patent No. 4,344,878 describes a flame retardant linear polyester composition containing a flame-retardant additive and polytetrafluoroethylene. Although it is stated in the '878 patent that many flame retardant materials may be used, the only exemplified system iS a halogen-containing polycarbonate in admixture with antimony oxide.
U.S. Patent No. 4,107,232 describes flame retardant non-dripping polyphenylene ethers and acrylonitrile-butadiene-styrene (ABS) and alpha-methylstyrene copolymers con~aining a halogenated flame retardant and PTFE.
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U.S. Patent ~Jo. 3,671,487 descri~es flame retardant, non-dripping polyester resin compositions containing fiberglass, a flame retardant ~dditive and PTFE. The flame retardant additives of this ~isclosure are broadly disclosed as the halogenated, antimony, phosphoric and nitrogen containing compounds. Illustrative examples of the flame-retardant additive are stated to be red phosphorus, triphenyl phosphate, halogenated aromatics. Polytetrafluoroethylene (PTFE) is reported to be a drip retardant in this and in certain of the above disclosures.
As can be seen for the fotegoing, the polymer compositions reported above are not in the polyolefin group even though halogenated flame retardant polyolefins are widely used. We have found that the addition of a PTFE drip retardant destroys or substantially reduces the flame retardant properties of such compo~itions.
- It is an object of this invention to provide improved intumescent flame-retardant additive compositions containing a minor amount of polytetrafluoroethylene.
It is a further object of this invention to provide flame retar~dant polypropylene~compositions of improved efficienc~ which employ reduced loadings of flame-retardant additives which results in improved physicai properties, better processability and reduced costs.
SUMMARY OF THE INVENTION
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This invention is directed to novel intumescent flame-retardant additive compositions of an ammonium phosphate or an amine phosphate and a hydroxyalkyl isocyanurate containing a minor amount of polytetrafluoroethylene for imparting improved flame retardancy to polymers. The intumescent flame-retardant additive composition of the invention is employed in polymeric compositions in an amount of about 5 to 50 percent by weight based upon the total weight of the composition, preferably about 20 to 40 percent and more preferably about 25 to 35 percent. The amount of polytetrafluoroethylene employed in compositions of the invention is from about 0.1 percent to about 3 percent by weight, preferably about 0.3 to about 2.0 percent and more preferably about 0.3 to about~1.0 percent based upon the total weight of po~ymer and the flame re~arda,lt additive. The novel, in~e~cer~
additive compositions of the invention are particularly useful in imparting flame retardancy to polypropylene and polyester -polyether copolymers.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
Intumescent flame retardant polymer compositions are well known. Intumescent flame retardancy is imparted to a normaliy comb~stible polymer by the incorporation into the polymer, additives which cause the polymer to bubble, foam and char when subjected to the high temperature of a flame. A multiceilular foam or char is formed on the surface of the burning polymer which produces an ins~lating effect and flame retardancy.
Examples of the use of intumescent flame retardants for polymers may be found in U.S. Patent 3,810,862; U.S. Patent 3,936,4l6; U.S. Patent 4,193,945; U.S. PatenS 4,198,993; U.S.Patent 4,504,610; U.S. Patent 4,137,199 and U.S. Patent 4,727,102; the teachings of hhich are incorporated herein by reference.
The efficiency of specific intumescent systems derived from ammonium pha.phJ~ s ~: amine rhosphat~s al.d tris ~hydroxyalkyl) isocyanurates, preferabiy ammonium polyphosphate and tris (2-hydroxyethyl) isocyanurate (THEIC) respectively, with or without an optional blowing agent, is significantly enhanced by the addition of a minor amount of PTFE to the additive system.
The intumescent flame-retardant additive is employed in an amount of about 5 to 50 percent by weight based upon the total weish. of the polymer and additive, preferably about 20 to 40 percent and more preferably about 25 to 35 percent. The amount of polytetrafluoroethylene employed in compositions of the invention is from about 0.1 percent to about 3 percent by weight, preferably about 0.3 to about 2.0 percent and more preferably about 0.3 to about 1.0 percent based upon the combined weight of po1ymer and additive.
Any of the varlous synthetic hydrocarbon polymers or polymer compositi~ons may be treated, both thermoplastic and thermoset, for instance a polyolefin, like polyethylene, ~3~ 3 polypropylene, polybutyle~e-l, and poly-4-met-hylpentene-1; a ~--copolymer of one or more olefins, like a crystalline copolymer of ethylene and propylene, a r~bber-like copolymer of ethylene, propylene and cyclopentadiene as the thircl ~onomer, and other elastomeric materials such as polyester-polyether copolymers, thermoplastic polyurethanes; a homo- and copolymer of alkenylaromatic compounds, such as polystyrene and polymethylstyrene; a copolymer of an alkenyl-aromatic compound and butadiene and~o~ acrylonitrile, such as a rubber-like styrene-butadiene copolymer, a copolymer of styrene and acrylonitrile or a graft copolymer of styrene and/or acrylonitrile on polybutadiene (ABS resin~; acrylic polymers, like polyethyl acrylate and polymethylmethacrylate; a cellulose derivative, such as celiulose acetate and cellulose nitrate; a phenolformaldehyde resin; a urea-formaldehyde resin; a .nelamine-formaldehyde resin; a pol~amid~; a po~y~ster, (thermoplastic and thermoset); polyvinylchloridei polyformaldehyde; butyl rubber, polyisoprene and other kinds of rubber; an epoxy resin; a polycarbonate, etc. and mixtures or blends thereof. Excellent results are attained with polymers such as polypropylene and polyester-polyether copolymers.
The flame retardant polymer compositions according to the present invention may be prepared by conventional methods. It is preferable that the flame retardants and other additives be dispersed in the polymer as uniformly as possible. Therefore, a-ny of the known methods which are suitable for obtaining a uniform dispersion may be used. In accordance with one method, the intumescent flame-retardant additives may be added to the parti~culated polymer which can be optionally mixed to obtain a uniform blend; the mixture or blend may be melt-blended in an extruder, and formed into pellets. In another method, the powdered~or ground polymer and intumescent flame-retardant additives may be uniformly mixed and formed into granulates, tablets or pellets by conventional methods. A blend of the _ tablets or pellets ~ay be fed to an extruder for ~elt ~ixing and pelletizins. The blend may aiso be directly fed to a molding machine such as screw injection molding machine. Alternativeiy, a master batch pellet or particle containiny a high concentration of the flame-retardant additive compounds and io~ concentration of polymer may be prepared on a roll mill or a mixing extruder.
The master batch pellets may be then blended with the polymer and processed as described above.
The ammonium phosphate of the additive system may be selected from monoammonium phosphate, diammonium phosphate, ammonium hypophosphate, ammonium orthophosphate, ammonium mono and dihydrogen phosphate and ammonium polyphosphate.
The ammonium phosphate component o the invention is preferably a free flowing, pulverulent, sparingly water-soluble, ammon um polypho~phate of the formula (NH4Po3)n~ i~ wh ch n stands for an integer from about 200 to 1000, preferably about 700, with a parti~cle size such that more than 99 weight percent of the particles have a size of less than 45 um. An example of such a polyphosphate is "Exolit 422" tregistered ~rademark; --manufactured and sold by Hoechst AG) having the composition (NH4PO3)n' in which n is higher than 200.
The ammonium polyphosphate may contain 0.5 to 25 weight %
of a) a water-insoluble artiicial, preferably cured, resin encapsulating the individual ammonium palyphosphate particles;
b) a reaction product of a polyisocyanate with a carbodimidization catalyst, the polycarbodiimide formed encapsulating the individual ammonium polyphosphate particles;
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c) a reaction product of a polyisocyanate and 2 polyhydroxy compound, the polyurethane formed encaps~llatin~ the individual am~onium polyphosphate particies;
d) a reaction product of a polyisocyanate with a trimerization catalyst, the poiyisocyanurate formed encapsulating the individual ammonium pol~phosphate particles;
e) a reaction product of a polyisocyanate and water, the polyurea formed encapsulating the individual ammonium polyphosphate particles;
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f) a cured melamine~formaldehyde-resin, the ml`ne~formP1dehyde resir. encapsulating the individual ammonium polyphosphate particles;
g) a cured epoxide resin, the epoxide resin encapsulating the individual ammonium polyphosphate~particles.
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~ Amine;phosphates which can serve as a source of phosphoric acid under combustion conditions are urea phosphate, guanyl urea phosphate, and melamine phosphate.
The compositions of the present invention may further contain dyestuffs, pigments, fillers, inorganic metal oxides and salts, fiber-reinforcing agent, lubricants, plasticizers, antistatlc ~agents and stabilizers.
The flame retardancy is determined on the polymeric compositions;either by measuring the oxygen index (according to ASTM D 2a63),~ which measures the ~inimum percentage of 2 in a ~5~
O2/N2 mixture required by the specimen for continuous burning,_~r by applying the well known UL-94 test ("Underwriters Laboratories").
The UL 94 test encompasses various ratings to classify the test specimen at different levels of flame retardancy. In the tests recorded herein use has been made of the Verti~al Burning Test, which enables one to classify the flame retardancy of a material at the following decreasing classification standards:
V-0 (best~, V-l and V-2. Each test is carried out on a group of 5 specimens, that may have a thickness of l/2", 1/4", l/8", or l/l6n. The specimen is kept in the vertical position by means of a suitable support, it is ignited with a flame at its lower end and two attempts at ignition, each lasting 10 seconds are made.
A cotton gauze is placed below the specimen ~o measure flame spread caused by àripping burning particles.
The three levels Or _i~,ia re~ardancy mentioncd he-einab3ve can~be defined as follows:
A rating of "V-0" means no specimen burns for more than 10 secon~ds after each flame application. Burning particles that drop from the specimen do not ignite the cotton gauze.
Furthermore, the total combustion time does not exceed 50 seconds for the 10 attempts made on the 5-specimen group. A rating of "'v~ means combustion~times up to 30 seconds for individual spec~men and up to 250 seconds for the 10 attempts made on the 5-specimen group are allowable. Also, under this rating no specimen produces burning droplets that ignite the cotton gauze.
~ A rating of "V-2~ means the allowable combustion times are the same as those of level V-l, but dripping burning particles ignite~the cotton gauze.
Polytetrafluoroethylenes useful in providing the improved intumescent flame-retardant additive systems of this invention are readily available. The polytetrafluoroethylene may be used ::
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in the solid form and simply dry blended with the other flame-retardant additives. This mixture in turn may be blended with a polymer. Generally about 0.3 to 9.0 % by weight of polytetrafluoroethylene based on the weight of the intumescent flame-retardant additive composition is used; more preferably, about 0.9 to 3.0 %. The effective amount of polytetrafluoroethylene required to impar~ improved flame retardancy may be determined by simple experimentation.
Intumescent flame-retardant systems particularly useful with this invention are those based upon ammonium phosphate.
Generally, the intumescent flame retardant composition will contain from about 50 to 95~ by weight of the ammonium phosphate component.~ In addition, it will contain a char forming additive, e.g. tris(2-hydroxyethyl)-isocyanurate (THEIC), in an amount of about 5 to 50%. The third component being polytetra-fluoroetn~le.-a in an amount of 0.3 to 9%. ~ a fourth compo~ent, the intumescent flame-retardant system may contain an optional biowing agent, an organic component which upon exposure to heat, decomposes generating volatile inert gases. The blowing agent generally comprises about 5 to 40% by weight of the total flame-retardant additive system. The blowing agent is preferably a nitrogen containing compound which releases large amounts of sas under the 1nfluence of heat. Urea, melamine, guanidine, dicyandiamide, butyl urea, glycine, benzene sulfonyl hydrazine, chlorinated paraffin, cyanuric acid, benzoguanamine, melamine cyanorate and hydroxyalkyl-amino-s-triazines are illustrative examples of typical blowing agents. The above percentage being based upon the total weight of the flame retardant additive composit~ion.
The char forming additive is selected from tris (hydroxyalkyl) isocyar.urates wherein the alkyl group may contain from l to 10 carbons which may be eittler linear or branched.
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_ Typical examples of such char forming additives are the ~ethyl, ethyl, propyl, butyl, pentyl or hexyl - tris (hydroxyalkyi~
isocyanurates, preferably tris (2-hydroxyethyl) isocyanurate.
Polytetrafluoroethylenes (PTFE) which have been found useful in imparting improved fiame retardancy to intumescen~
flame retardant systems according to this invention may be characterized as follows: particle size 1.0-1000 microns, preferably < 20 microns, and melt viscosity (at 350C) lB2-1014 poise, generally above 103 poise Useful available PTFE products are Hostaflo ~ (Hoechst) 1645, 1702, 9205, and Teflo ~ (Dupont) ~-10 and type 6.
'` Within the above ranges of particle size and melt viscosity preferred values for the PTFE additive may be determined for the base polymer by simple experimentation. In the case of a polypropylene, a PTFE melt viscosity of 10 to 1~ poise and a p~rti~le size of 1 to 100 microns is preferred, most preferablv a melt viscosity of about 100 to 1000 poise. Simiiarly, it has been found that for a polyester-polyether copolymer base resin (Ritefle ~ available from Hoechst Celanese Corporation, Somerville, New Jersey), the preferred value of melt viscosity and particle slze were 101l to 1014 poise and 300-500 microns, respectively.
PTFE functions synergistically within the char-forming system, exhibiting fluxing action that assists in disbursing heat from the substrate. Further, this fluxing or fluidizing action regulates the phase change behavior (liquid to solid) in the char-forming process, such that the intumescent or foaming reaction, in~itiated by inert gases formed upon burning, becomes more ~effective. The end-result is an insulative char of increased structural integrity that serves as a more efficient protective barrier to further burning. Typical examples of intumescent flame-retardant systems which may be improved by the addition of PTFE are shown in the following examples and summarized in Table I. - 13 -~;~.gt3~
Example l The following additives were used in the indicated amounts for this example:
. 89~ g of Pro~ax~ 5323 - a pelletized polypropy1ene with a melt index of 10-12; from Himont.
. l80 g of Exolit~ q22 - a fine powder grade ammonium polyphosphate; for~ula (NH4PO3)n in which n is about 700; avg.
particle size - 18 microns; from Hoechst Celanese Corp~
. 90 g of Tris (2-hydroxyethyl) isocyanurate - a fine powder from ~ASF.
. 90 g of melamine cyanurate - a fine powder; avg.
particle size < 10 micron; from SKW (Germany).
The above ingredients were dry-blended/ melt blended in a Banbury Mixer at 160-180 degrees C and chopped in a lab size granulator. The granulated material was compression molded at 175 degrees C into ~ " X l~16" plaques that were cut to size for flammability testing. Results are reported in Table I for Examples l - 15.
Example 2 Same procedure as Example l, employing 900 g Profax 6323 polypropylene, 150 g Exolit 422/ ammonium polyphosphate/ 75 g THEIC/ and 75 g melamine cyanurate.
Example 3 Same procedure as Example l, employing 894 g Profax 6323 polypropylene, 150 g Exolit 422, ammonium polyphosphate, 75 g THEIC, 75 g melamine cyanurate and 6 g of Hostaflo ~ 9205 polytetrafluoroethylene (PTFE) from Hoechst Celanese Corporation.
Example 4 Same procedure as Example l, employing 840 g Profax 6323 polypropylene( 216 g Exollt 422/ ammonium polyphosphate/ 72 g THEIC and 72 g melamine cyanurate.
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E xam~le 5 ~
Same procedure as Exa~ple 1, employing 900 g Profax ~323 polypropylene, 180 g Exolit 422, ammonium polyphosphate, 60 g THEIC, and 60 g melamine cyanurate.
Example 6 Same procedure as Example 1, employing 894 g Profax 6323 polypropylene, 180 9 Exolit 422, ammonium polyphosphate, 60 g THEIC, 60 g melamine cyanurate and 6 g of Hostaflon 9205 PTFE.
Example 7 Same procedure as Example 1, employing 8g0 9 Profax 6323 polypropylene, 252 g Exolit 422, ammonium polyphosphate, 54 g THEIC and 54 g melamine cyanurate.
Example 8 Same procedure as Example 1, employing 900 g Profax 6323 polypropylene, 210 g Exolit 422, ammonium polyphosphate, 45 g THElC an~ 45 9 melamine cyanurate.
Example 9 Same procedure as Example 1, employing 894 g Profax 6323 polypropylene, 210 g Exolit 422, ammonium polyphosphate, 45 g THEIC, 45 g melamine cyanurate and 6 g Hostaflon 9205 PTFE.
Example 10 Same procedure as Example 1, employing 780 g Profax 6323 polypropylene, 251 g Exolit 422, ammonium polyphosphate, and 168 g THEIC.
Exam~Ie 11 ' Same procedure as Example l, employing 840 ~ Profax 6323 polypropylene, 216 g Exolit 422, ammonium polyphosphate and 144 g THEIC.
Exam~le 12 Same procedure as Example 1, employing 834 g Profax 6323 polypropyl~ene, 216 g Exolit 422, ammonium polyphosphate, 144 g THEIC and 6 g Hostaflon 9205 PTFE.
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Example l3 .
Same procedure as Example l, employing 7~30 g Profax 6323 polypropylene 348 g Exolit 422, ammonium polyphosphate, and 72 g THEIC.
Example 14 Same procedure as Example 1, emp]oying 840 g Profax 6323 polypropylene, 300 g Exolit 422, ammonium polyphosphate, and 60 g THEIC.
Example 15 Same procedure as Example l, employing 834 g Profax 6323 polypropylene, 300 g Exolit 422, ammonium polyphosphate, 60 g THEIC, and 6 g Hostaflon 9205 PTFE.
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5~3 The following comparative examples 16 - 19 iliustrate how PTFE is detrime~tal to the performance of haloaen based flame retardant polypropylene compositions. The flame retardancy results of these examples are listed in Table II.
Example 16 Same procedure as Example 1, employing 684 g Profax 6323 polypropylene, 408 g Dechlorane Plu ~, (a chlorinated cycloaliphatic compound from Occidental Chemical Corporation) 43.2 g antimony trioxide (Sb2O3), and 64.8 g of zinc borate (ZnB03) .
Same procedure as Example 1, employing 678 g Profax 6323 p~'yp~opylene, 408 g Dechlorano D]ll ~, 43.2 g antimony trioxide (Sb2O3), 64.8 g zinc borate (ZnBO3), and 6 g Hostaflon 9205 PTFE.
Example 18 Same procedure as Example 1, employing 804 g Profax 6323 polypropylene, 300 g decabromodiphenyl oxide, and 96 g antimony trioxide (Sb2O3)~
Example 19 Same procedure as Example 1, employing 798 g PrOfax 6323 polypropylene, 300 g decabromodiphenyl oxide, 96 9 antimony trioxide (5b2O3), and 6 g Hostaflo ~ 9205 PTFE.
~3(~ 3 The above comparative experiments show the ineffecti~eness, and in fact, detrimental effeot of the PTFE additive in halogen-based flame retardant form~lations.
TABJ,E II
E_amples ~Wt. ~) Formulation 16 17 18 19 Control Polypropylenel 57 56.567 66.5 100 Cl-Alicyclic2 34 34 DBDPo3 _ ____25 25 ___ Sb23 ` 3.6 3.68 8 ---Zn3O3 5.4 5.4 -- __ ___ Polytetrafluoraethylene4 ---- 0.5 -- 0.5 ---(PTFE) JL94 (Y~L^~.) @ 1~ V-O V-2 V-1 ~ e Avg. burn time (Sec.)63.511.5 8.~ -- ---Oxygen Index 29.2 24.6 26.4 24.7 17.2 Injection moldable (M.I. = 9-10), Profax 6323 poiypropylene 2 Dechlorane Plus~ from Occidental Chemical 3 Decabromodiphenyl Oxide 4 Hostaflo ~ 9205 PTFE from Hoechst-ceIanese V-O (best) > V-1 > V-2; B = continuous burn 6 Average of two 10 sec. burns on S bars ' :
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BAC~G RoUND OF TH E I NVENT I ON
~_ ___ Char forming or intumescent flame retardant compositions are well known in the paint, coating and plastic fields.
These systems qenerally consist of three components, an acid generating component, a char forming component and a blowing agent. A well known intumescent flame re~ardant is the ammoniu~
polyphosphate (APP)~dipentaerythritol (DPET)~elamine (ME) system.
The theory and background of such intumescent flame retardant systems is widely reported in the literature, see e.g., The Chemistry and Uses of Flame Reta~dants", John Lyons, p. 256 - 280, (1970) and "Intumescen~ Coating Systems, Their Development and Chemistry"t H. L. Vandersall, J. Fire &
~lammability, Vol. 2, p. 97, (April 1970).
V~ndersal' describ~s ti,~ comn,erciai use of the ammonium polyphosphate (acid generator), dipentaerythritol (char former) and melamine (blowing agent) system in the paint/coating area and U.S. Patent No. 3,810,862 describes the use of this APP/DPET/ME
system in plastics. U.S. Patent No. 4,198,493 describes a similar intumescent flame retardant system for use in paints and plastics in which the polyhydroxy component, dipentaerythritol is replaced by the polyhydroxy compoundl tris(2-hydroxyethyl)-isocyanurate.
Similarly, flame retardant polymer compositions based upon halogenated organic compounds, phosphorus containing organic compounds and halogenated organic compounds - antimony oxide mixtures are well known. The addition of such flame-retardant additives to polymers has the effect of reducing the physical properties of the polymer. Therefore, it has been the object of workers ~in this field to endeavor to obtain maximum flame ~3~
retardancy using the lowest amount of fla~e-retardant additive in both intumescent and halogen/ phosphorus organic compounds systems.
The 1ame retardancy of a polymer composition can be measured by the UL-94 tes~ method (Underwriters Laboratories Inc.) This test is well known and is incorporated herein by reference. Flame retardancy is rated V-0 (best), V-l, V-2 under the UL-94 test method which rates performance on the basis of time for the test specimen to stop burning in air and the presence or absence of a flame spreadinq drip from ~he test specimen.
In vie~ of the fact that the presence of dripping, flaming polymer droplets increase the rate of spread of a fire, efforts have been made to prod~ce flame retardant polymer compositions which do not exhibit this flame spreading tendency. These prior attemptS to prod~ c:, ;Jperior _ompositlons ~re based upon the halogenated or phos~horus-organic compound type flame retardant systems, perhaps because the intumescent type flame retardant systems are generally more drip retardant than these systems.
Examples of some of the reported flame retardant systems follow.
U.S. Patent 4,490,504 describes improved flame retardant composition sulfur-containing polycarbonates and fiberglass.
U.S. Patent No. 4,344,878 describes a flame retardant linear polyester composition containing a flame-retardant additive and polytetrafluoroethylene. Although it is stated in the '878 patent that many flame retardant materials may be used, the only exemplified system iS a halogen-containing polycarbonate in admixture with antimony oxide.
U.S. Patent No. 4,107,232 describes flame retardant non-dripping polyphenylene ethers and acrylonitrile-butadiene-styrene (ABS) and alpha-methylstyrene copolymers con~aining a halogenated flame retardant and PTFE.
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U.S. Patent ~Jo. 3,671,487 descri~es flame retardant, non-dripping polyester resin compositions containing fiberglass, a flame retardant ~dditive and PTFE. The flame retardant additives of this ~isclosure are broadly disclosed as the halogenated, antimony, phosphoric and nitrogen containing compounds. Illustrative examples of the flame-retardant additive are stated to be red phosphorus, triphenyl phosphate, halogenated aromatics. Polytetrafluoroethylene (PTFE) is reported to be a drip retardant in this and in certain of the above disclosures.
As can be seen for the fotegoing, the polymer compositions reported above are not in the polyolefin group even though halogenated flame retardant polyolefins are widely used. We have found that the addition of a PTFE drip retardant destroys or substantially reduces the flame retardant properties of such compo~itions.
- It is an object of this invention to provide improved intumescent flame-retardant additive compositions containing a minor amount of polytetrafluoroethylene.
It is a further object of this invention to provide flame retar~dant polypropylene~compositions of improved efficienc~ which employ reduced loadings of flame-retardant additives which results in improved physicai properties, better processability and reduced costs.
SUMMARY OF THE INVENTION
_ _ .
This invention is directed to novel intumescent flame-retardant additive compositions of an ammonium phosphate or an amine phosphate and a hydroxyalkyl isocyanurate containing a minor amount of polytetrafluoroethylene for imparting improved flame retardancy to polymers. The intumescent flame-retardant additive composition of the invention is employed in polymeric compositions in an amount of about 5 to 50 percent by weight based upon the total weight of the composition, preferably about 20 to 40 percent and more preferably about 25 to 35 percent. The amount of polytetrafluoroethylene employed in compositions of the invention is from about 0.1 percent to about 3 percent by weight, preferably about 0.3 to about 2.0 percent and more preferably about 0.3 to about~1.0 percent based upon the total weight of po~ymer and the flame re~arda,lt additive. The novel, in~e~cer~
additive compositions of the invention are particularly useful in imparting flame retardancy to polypropylene and polyester -polyether copolymers.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
Intumescent flame retardant polymer compositions are well known. Intumescent flame retardancy is imparted to a normaliy comb~stible polymer by the incorporation into the polymer, additives which cause the polymer to bubble, foam and char when subjected to the high temperature of a flame. A multiceilular foam or char is formed on the surface of the burning polymer which produces an ins~lating effect and flame retardancy.
Examples of the use of intumescent flame retardants for polymers may be found in U.S. Patent 3,810,862; U.S. Patent 3,936,4l6; U.S. Patent 4,193,945; U.S. PatenS 4,198,993; U.S.Patent 4,504,610; U.S. Patent 4,137,199 and U.S. Patent 4,727,102; the teachings of hhich are incorporated herein by reference.
The efficiency of specific intumescent systems derived from ammonium pha.phJ~ s ~: amine rhosphat~s al.d tris ~hydroxyalkyl) isocyanurates, preferabiy ammonium polyphosphate and tris (2-hydroxyethyl) isocyanurate (THEIC) respectively, with or without an optional blowing agent, is significantly enhanced by the addition of a minor amount of PTFE to the additive system.
The intumescent flame-retardant additive is employed in an amount of about 5 to 50 percent by weight based upon the total weish. of the polymer and additive, preferably about 20 to 40 percent and more preferably about 25 to 35 percent. The amount of polytetrafluoroethylene employed in compositions of the invention is from about 0.1 percent to about 3 percent by weight, preferably about 0.3 to about 2.0 percent and more preferably about 0.3 to about 1.0 percent based upon the combined weight of po1ymer and additive.
Any of the varlous synthetic hydrocarbon polymers or polymer compositi~ons may be treated, both thermoplastic and thermoset, for instance a polyolefin, like polyethylene, ~3~ 3 polypropylene, polybutyle~e-l, and poly-4-met-hylpentene-1; a ~--copolymer of one or more olefins, like a crystalline copolymer of ethylene and propylene, a r~bber-like copolymer of ethylene, propylene and cyclopentadiene as the thircl ~onomer, and other elastomeric materials such as polyester-polyether copolymers, thermoplastic polyurethanes; a homo- and copolymer of alkenylaromatic compounds, such as polystyrene and polymethylstyrene; a copolymer of an alkenyl-aromatic compound and butadiene and~o~ acrylonitrile, such as a rubber-like styrene-butadiene copolymer, a copolymer of styrene and acrylonitrile or a graft copolymer of styrene and/or acrylonitrile on polybutadiene (ABS resin~; acrylic polymers, like polyethyl acrylate and polymethylmethacrylate; a cellulose derivative, such as celiulose acetate and cellulose nitrate; a phenolformaldehyde resin; a urea-formaldehyde resin; a .nelamine-formaldehyde resin; a pol~amid~; a po~y~ster, (thermoplastic and thermoset); polyvinylchloridei polyformaldehyde; butyl rubber, polyisoprene and other kinds of rubber; an epoxy resin; a polycarbonate, etc. and mixtures or blends thereof. Excellent results are attained with polymers such as polypropylene and polyester-polyether copolymers.
The flame retardant polymer compositions according to the present invention may be prepared by conventional methods. It is preferable that the flame retardants and other additives be dispersed in the polymer as uniformly as possible. Therefore, a-ny of the known methods which are suitable for obtaining a uniform dispersion may be used. In accordance with one method, the intumescent flame-retardant additives may be added to the parti~culated polymer which can be optionally mixed to obtain a uniform blend; the mixture or blend may be melt-blended in an extruder, and formed into pellets. In another method, the powdered~or ground polymer and intumescent flame-retardant additives may be uniformly mixed and formed into granulates, tablets or pellets by conventional methods. A blend of the _ tablets or pellets ~ay be fed to an extruder for ~elt ~ixing and pelletizins. The blend may aiso be directly fed to a molding machine such as screw injection molding machine. Alternativeiy, a master batch pellet or particle containiny a high concentration of the flame-retardant additive compounds and io~ concentration of polymer may be prepared on a roll mill or a mixing extruder.
The master batch pellets may be then blended with the polymer and processed as described above.
The ammonium phosphate of the additive system may be selected from monoammonium phosphate, diammonium phosphate, ammonium hypophosphate, ammonium orthophosphate, ammonium mono and dihydrogen phosphate and ammonium polyphosphate.
The ammonium phosphate component o the invention is preferably a free flowing, pulverulent, sparingly water-soluble, ammon um polypho~phate of the formula (NH4Po3)n~ i~ wh ch n stands for an integer from about 200 to 1000, preferably about 700, with a parti~cle size such that more than 99 weight percent of the particles have a size of less than 45 um. An example of such a polyphosphate is "Exolit 422" tregistered ~rademark; --manufactured and sold by Hoechst AG) having the composition (NH4PO3)n' in which n is higher than 200.
The ammonium polyphosphate may contain 0.5 to 25 weight %
of a) a water-insoluble artiicial, preferably cured, resin encapsulating the individual ammonium palyphosphate particles;
b) a reaction product of a polyisocyanate with a carbodimidization catalyst, the polycarbodiimide formed encapsulating the individual ammonium polyphosphate particles;
_ g _ ~,~3C~ 3~
c) a reaction product of a polyisocyanate and 2 polyhydroxy compound, the polyurethane formed encaps~llatin~ the individual am~onium polyphosphate particies;
d) a reaction product of a polyisocyanate with a trimerization catalyst, the poiyisocyanurate formed encapsulating the individual ammonium pol~phosphate particles;
e) a reaction product of a polyisocyanate and water, the polyurea formed encapsulating the individual ammonium polyphosphate particles;
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f) a cured melamine~formaldehyde-resin, the ml`ne~formP1dehyde resir. encapsulating the individual ammonium polyphosphate particles;
g) a cured epoxide resin, the epoxide resin encapsulating the individual ammonium polyphosphate~particles.
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~ Amine;phosphates which can serve as a source of phosphoric acid under combustion conditions are urea phosphate, guanyl urea phosphate, and melamine phosphate.
The compositions of the present invention may further contain dyestuffs, pigments, fillers, inorganic metal oxides and salts, fiber-reinforcing agent, lubricants, plasticizers, antistatlc ~agents and stabilizers.
The flame retardancy is determined on the polymeric compositions;either by measuring the oxygen index (according to ASTM D 2a63),~ which measures the ~inimum percentage of 2 in a ~5~
O2/N2 mixture required by the specimen for continuous burning,_~r by applying the well known UL-94 test ("Underwriters Laboratories").
The UL 94 test encompasses various ratings to classify the test specimen at different levels of flame retardancy. In the tests recorded herein use has been made of the Verti~al Burning Test, which enables one to classify the flame retardancy of a material at the following decreasing classification standards:
V-0 (best~, V-l and V-2. Each test is carried out on a group of 5 specimens, that may have a thickness of l/2", 1/4", l/8", or l/l6n. The specimen is kept in the vertical position by means of a suitable support, it is ignited with a flame at its lower end and two attempts at ignition, each lasting 10 seconds are made.
A cotton gauze is placed below the specimen ~o measure flame spread caused by àripping burning particles.
The three levels Or _i~,ia re~ardancy mentioncd he-einab3ve can~be defined as follows:
A rating of "V-0" means no specimen burns for more than 10 secon~ds after each flame application. Burning particles that drop from the specimen do not ignite the cotton gauze.
Furthermore, the total combustion time does not exceed 50 seconds for the 10 attempts made on the 5-specimen group. A rating of "'v~ means combustion~times up to 30 seconds for individual spec~men and up to 250 seconds for the 10 attempts made on the 5-specimen group are allowable. Also, under this rating no specimen produces burning droplets that ignite the cotton gauze.
~ A rating of "V-2~ means the allowable combustion times are the same as those of level V-l, but dripping burning particles ignite~the cotton gauze.
Polytetrafluoroethylenes useful in providing the improved intumescent flame-retardant additive systems of this invention are readily available. The polytetrafluoroethylene may be used ::
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in the solid form and simply dry blended with the other flame-retardant additives. This mixture in turn may be blended with a polymer. Generally about 0.3 to 9.0 % by weight of polytetrafluoroethylene based on the weight of the intumescent flame-retardant additive composition is used; more preferably, about 0.9 to 3.0 %. The effective amount of polytetrafluoroethylene required to impar~ improved flame retardancy may be determined by simple experimentation.
Intumescent flame-retardant systems particularly useful with this invention are those based upon ammonium phosphate.
Generally, the intumescent flame retardant composition will contain from about 50 to 95~ by weight of the ammonium phosphate component.~ In addition, it will contain a char forming additive, e.g. tris(2-hydroxyethyl)-isocyanurate (THEIC), in an amount of about 5 to 50%. The third component being polytetra-fluoroetn~le.-a in an amount of 0.3 to 9%. ~ a fourth compo~ent, the intumescent flame-retardant system may contain an optional biowing agent, an organic component which upon exposure to heat, decomposes generating volatile inert gases. The blowing agent generally comprises about 5 to 40% by weight of the total flame-retardant additive system. The blowing agent is preferably a nitrogen containing compound which releases large amounts of sas under the 1nfluence of heat. Urea, melamine, guanidine, dicyandiamide, butyl urea, glycine, benzene sulfonyl hydrazine, chlorinated paraffin, cyanuric acid, benzoguanamine, melamine cyanorate and hydroxyalkyl-amino-s-triazines are illustrative examples of typical blowing agents. The above percentage being based upon the total weight of the flame retardant additive composit~ion.
The char forming additive is selected from tris (hydroxyalkyl) isocyar.urates wherein the alkyl group may contain from l to 10 carbons which may be eittler linear or branched.
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_ Typical examples of such char forming additives are the ~ethyl, ethyl, propyl, butyl, pentyl or hexyl - tris (hydroxyalkyi~
isocyanurates, preferably tris (2-hydroxyethyl) isocyanurate.
Polytetrafluoroethylenes (PTFE) which have been found useful in imparting improved fiame retardancy to intumescen~
flame retardant systems according to this invention may be characterized as follows: particle size 1.0-1000 microns, preferably < 20 microns, and melt viscosity (at 350C) lB2-1014 poise, generally above 103 poise Useful available PTFE products are Hostaflo ~ (Hoechst) 1645, 1702, 9205, and Teflo ~ (Dupont) ~-10 and type 6.
'` Within the above ranges of particle size and melt viscosity preferred values for the PTFE additive may be determined for the base polymer by simple experimentation. In the case of a polypropylene, a PTFE melt viscosity of 10 to 1~ poise and a p~rti~le size of 1 to 100 microns is preferred, most preferablv a melt viscosity of about 100 to 1000 poise. Simiiarly, it has been found that for a polyester-polyether copolymer base resin (Ritefle ~ available from Hoechst Celanese Corporation, Somerville, New Jersey), the preferred value of melt viscosity and particle slze were 101l to 1014 poise and 300-500 microns, respectively.
PTFE functions synergistically within the char-forming system, exhibiting fluxing action that assists in disbursing heat from the substrate. Further, this fluxing or fluidizing action regulates the phase change behavior (liquid to solid) in the char-forming process, such that the intumescent or foaming reaction, in~itiated by inert gases formed upon burning, becomes more ~effective. The end-result is an insulative char of increased structural integrity that serves as a more efficient protective barrier to further burning. Typical examples of intumescent flame-retardant systems which may be improved by the addition of PTFE are shown in the following examples and summarized in Table I. - 13 -~;~.gt3~
Example l The following additives were used in the indicated amounts for this example:
. 89~ g of Pro~ax~ 5323 - a pelletized polypropy1ene with a melt index of 10-12; from Himont.
. l80 g of Exolit~ q22 - a fine powder grade ammonium polyphosphate; for~ula (NH4PO3)n in which n is about 700; avg.
particle size - 18 microns; from Hoechst Celanese Corp~
. 90 g of Tris (2-hydroxyethyl) isocyanurate - a fine powder from ~ASF.
. 90 g of melamine cyanurate - a fine powder; avg.
particle size < 10 micron; from SKW (Germany).
The above ingredients were dry-blended/ melt blended in a Banbury Mixer at 160-180 degrees C and chopped in a lab size granulator. The granulated material was compression molded at 175 degrees C into ~ " X l~16" plaques that were cut to size for flammability testing. Results are reported in Table I for Examples l - 15.
Example 2 Same procedure as Example l, employing 900 g Profax 6323 polypropylene, 150 g Exolit 422/ ammonium polyphosphate/ 75 g THEIC/ and 75 g melamine cyanurate.
Example 3 Same procedure as Example l, employing 894 g Profax 6323 polypropylene, 150 g Exolit 422, ammonium polyphosphate, 75 g THEIC, 75 g melamine cyanurate and 6 g of Hostaflo ~ 9205 polytetrafluoroethylene (PTFE) from Hoechst Celanese Corporation.
Example 4 Same procedure as Example l, employing 840 g Profax 6323 polypropylene( 216 g Exollt 422/ ammonium polyphosphate/ 72 g THEIC and 72 g melamine cyanurate.
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E xam~le 5 ~
Same procedure as Exa~ple 1, employing 900 g Profax ~323 polypropylene, 180 g Exolit 422, ammonium polyphosphate, 60 g THEIC, and 60 g melamine cyanurate.
Example 6 Same procedure as Example 1, employing 894 g Profax 6323 polypropylene, 180 9 Exolit 422, ammonium polyphosphate, 60 g THEIC, 60 g melamine cyanurate and 6 g of Hostaflon 9205 PTFE.
Example 7 Same procedure as Example 1, employing 8g0 9 Profax 6323 polypropylene, 252 g Exolit 422, ammonium polyphosphate, 54 g THEIC and 54 g melamine cyanurate.
Example 8 Same procedure as Example 1, employing 900 g Profax 6323 polypropylene, 210 g Exolit 422, ammonium polyphosphate, 45 g THElC an~ 45 9 melamine cyanurate.
Example 9 Same procedure as Example 1, employing 894 g Profax 6323 polypropylene, 210 g Exolit 422, ammonium polyphosphate, 45 g THEIC, 45 g melamine cyanurate and 6 g Hostaflon 9205 PTFE.
Example 10 Same procedure as Example 1, employing 780 g Profax 6323 polypropylene, 251 g Exolit 422, ammonium polyphosphate, and 168 g THEIC.
Exam~Ie 11 ' Same procedure as Example l, employing 840 ~ Profax 6323 polypropylene, 216 g Exolit 422, ammonium polyphosphate and 144 g THEIC.
Exam~le 12 Same procedure as Example 1, employing 834 g Profax 6323 polypropyl~ene, 216 g Exolit 422, ammonium polyphosphate, 144 g THEIC and 6 g Hostaflon 9205 PTFE.
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Example l3 .
Same procedure as Example l, employing 7~30 g Profax 6323 polypropylene 348 g Exolit 422, ammonium polyphosphate, and 72 g THEIC.
Example 14 Same procedure as Example 1, emp]oying 840 g Profax 6323 polypropylene, 300 g Exolit 422, ammonium polyphosphate, and 60 g THEIC.
Example 15 Same procedure as Example l, employing 834 g Profax 6323 polypropylene, 300 g Exolit 422, ammonium polyphosphate, 60 g THEIC, and 6 g Hostaflon 9205 PTFE.
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5~3 The following comparative examples 16 - 19 iliustrate how PTFE is detrime~tal to the performance of haloaen based flame retardant polypropylene compositions. The flame retardancy results of these examples are listed in Table II.
Example 16 Same procedure as Example 1, employing 684 g Profax 6323 polypropylene, 408 g Dechlorane Plu ~, (a chlorinated cycloaliphatic compound from Occidental Chemical Corporation) 43.2 g antimony trioxide (Sb2O3), and 64.8 g of zinc borate (ZnB03) .
Same procedure as Example 1, employing 678 g Profax 6323 p~'yp~opylene, 408 g Dechlorano D]ll ~, 43.2 g antimony trioxide (Sb2O3), 64.8 g zinc borate (ZnBO3), and 6 g Hostaflon 9205 PTFE.
Example 18 Same procedure as Example 1, employing 804 g Profax 6323 polypropylene, 300 g decabromodiphenyl oxide, and 96 g antimony trioxide (Sb2O3)~
Example 19 Same procedure as Example 1, employing 798 g PrOfax 6323 polypropylene, 300 g decabromodiphenyl oxide, 96 9 antimony trioxide (5b2O3), and 6 g Hostaflo ~ 9205 PTFE.
~3(~ 3 The above comparative experiments show the ineffecti~eness, and in fact, detrimental effeot of the PTFE additive in halogen-based flame retardant form~lations.
TABJ,E II
E_amples ~Wt. ~) Formulation 16 17 18 19 Control Polypropylenel 57 56.567 66.5 100 Cl-Alicyclic2 34 34 DBDPo3 _ ____25 25 ___ Sb23 ` 3.6 3.68 8 ---Zn3O3 5.4 5.4 -- __ ___ Polytetrafluoraethylene4 ---- 0.5 -- 0.5 ---(PTFE) JL94 (Y~L^~.) @ 1~ V-O V-2 V-1 ~ e Avg. burn time (Sec.)63.511.5 8.~ -- ---Oxygen Index 29.2 24.6 26.4 24.7 17.2 Injection moldable (M.I. = 9-10), Profax 6323 poiypropylene 2 Dechlorane Plus~ from Occidental Chemical 3 Decabromodiphenyl Oxide 4 Hostaflo ~ 9205 PTFE from Hoechst-ceIanese V-O (best) > V-1 > V-2; B = continuous burn 6 Average of two 10 sec. burns on S bars ' :
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Other Polymers The invention is operative and useful in other polymers as well. This is illustra~ed for a polyester/polyether elastomer (TPE) in Table III (Examples 20-22).
Example 20 Same procedure as Example 1, employing 780 g Ritefle ~ TPE, 252 g Exoli ~ 422, ammonium polyphosphate, 84 g THEIC, and 84 g of melamine cyanurate.
Example 21 - Same procedure as ~xample 1, employing 776.4 g Riteflex~
TPE, 252 g Exolit~ 422, ammonium phosphate, 84 g THEIC, 84 g melamine cyanurate, and 3.6 g Hostaflon 1645 PTFE.
Example 22 Same procedure as Example 1, employing 772.8 g Ritefle ~
TPE, 252 g Exolit 922, ammonium polyphosphate, 84 g THEIC, 84 g melamine cyanDrate, and 7.2 g dostaflon~ 1645 ?TFE.
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~t~(3 7~ 3 TABLE III
Exampies (Wt. ~) Formulation 20 21 22 Control Polyester Elastomer1 65 64.7 64.4 1~0 Ammonium Polyphosphate2 21 21 21 ---Melamine Cyanurate 7 7 7 ---Polytetrafluoroethylene5 (PTFE) --- 0.3 0.6 ___ UL94 (Vert.) @ 1/16 V-2 V-l V-0 B
Avg. Burn Time (Sec.)6.5 3.0 2.0 ___ Oxygen Index 27.6 28.5 29.9 20.5 1 Ritefle ~ TPE from Hoechst Celanese Exollt 422, ammonium poly_L~sp':~te from Ho~chst Celan^se 3 Tris (2-hydroxyethylj isocyanurate 4 Reaction~product of melamine and cyanuric acid.
5 Hostaflo ~ 1645 PTFE from Hoechst Celanese V-O (best) > V-1 j V-2; B = continuous burn.
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' Average of two 10 sec. burns on 5 bars.
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: ~ : -- :
Other Polymers The invention is operative and useful in other polymers as well. This is illustra~ed for a polyester/polyether elastomer (TPE) in Table III (Examples 20-22).
Example 20 Same procedure as Example 1, employing 780 g Ritefle ~ TPE, 252 g Exoli ~ 422, ammonium polyphosphate, 84 g THEIC, and 84 g of melamine cyanurate.
Example 21 - Same procedure as ~xample 1, employing 776.4 g Riteflex~
TPE, 252 g Exolit~ 422, ammonium phosphate, 84 g THEIC, 84 g melamine cyanurate, and 3.6 g Hostaflon 1645 PTFE.
Example 22 Same procedure as Example 1, employing 772.8 g Ritefle ~
TPE, 252 g Exolit 922, ammonium polyphosphate, 84 g THEIC, 84 g melamine cyanDrate, and 7.2 g dostaflon~ 1645 ?TFE.
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~t~(3 7~ 3 TABLE III
Exampies (Wt. ~) Formulation 20 21 22 Control Polyester Elastomer1 65 64.7 64.4 1~0 Ammonium Polyphosphate2 21 21 21 ---Melamine Cyanurate 7 7 7 ---Polytetrafluoroethylene5 (PTFE) --- 0.3 0.6 ___ UL94 (Vert.) @ 1/16 V-2 V-l V-0 B
Avg. Burn Time (Sec.)6.5 3.0 2.0 ___ Oxygen Index 27.6 28.5 29.9 20.5 1 Ritefle ~ TPE from Hoechst Celanese Exollt 422, ammonium poly_L~sp':~te from Ho~chst Celan^se 3 Tris (2-hydroxyethylj isocyanurate 4 Reaction~product of melamine and cyanuric acid.
5 Hostaflo ~ 1645 PTFE from Hoechst Celanese V-O (best) > V-1 j V-2; B = continuous burn.
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' Average of two 10 sec. burns on 5 bars.
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Claims (11)
1. An intumescent flame retardant additive composition consisting essentially of:
ammonium phosphate or an amine phosphate in an amount of from about 50 to 95 weight percent;
tris (hydroxyalkyl) isocyanurate in an amount of from about 5 to about 50 percent by weight; wherein said hydroxyalkyl contains 1 to 10 carbon atoms; and polytetrafluoroethylene in an amount from about 0.3 to about 9 percent by weight.
ammonium phosphate or an amine phosphate in an amount of from about 50 to 95 weight percent;
tris (hydroxyalkyl) isocyanurate in an amount of from about 5 to about 50 percent by weight; wherein said hydroxyalkyl contains 1 to 10 carbon atoms; and polytetrafluoroethylene in an amount from about 0.3 to about 9 percent by weight.
2. An intumescent flame retardant additive composition according to Claim 1 wherein said polytetrafluoroethylene is present in an amount from about 0.9 to about 3 weight percent.
3. An intumescent flame retardant additive composition according to Claim 1 which contains from about 5 to about 40 weight percent of a blowing agent compound.
4. An intumescent flame retardant additive composition according to Claim 3 which contains at least one blowing agent compound selected from urea, melamine, guanidine, dicyandiamine, butyl urea, glycine, benzene sulfonyl hydrazine, chlorinated paraffin, cyanuric acid, benzoguanamine, melamine cyanurate, hyùroxyalkyl-amino-s-triazine, melamine borate, melamine phosphate or melamine sulfate.
5. An intumescent flame retardant additive composition according to Claim 1, 2, 3 or 4 wherein said tris (hydroxyalkyl) isocyanurate is tris (2-hydroxyethyl) isocyanurate and said ammonium phosphate is ammonium polyphosphate.
6. A flame retardant polymeric composition of a synthetic hydrocarbon polymer selected from polypropylene and polyether-polyester compolymers and about 5 to about 50 percent by total weight based upon the weight of said polymer composition of an intumescent flame retardant additive, said additive consisting essentially of:
ammonium phosphate in an amount of from about 50 to about 95 percent by weight based upon the weight said additive;
tris (hydroxyalkyl) isocyanurate in an amount of from about 5 to 50 percent by weight based upon of weight of said additive; wherein said hydroxyalkyl contains 1 to 10 carbons;
and polytetrafluoroethylene in an amount of from about 0.3 to about 9 percent by weight based upon the weight of said additive.
ammonium phosphate in an amount of from about 50 to about 95 percent by weight based upon the weight said additive;
tris (hydroxyalkyl) isocyanurate in an amount of from about 5 to 50 percent by weight based upon of weight of said additive; wherein said hydroxyalkyl contains 1 to 10 carbons;
and polytetrafluoroethylene in an amount of from about 0.3 to about 9 percent by weight based upon the weight of said additive.
7. A flame retardant polymeric composition according to Claim 6 wherein said intumescent flame retardant additive is present in an amount of about 20 to 40 percent by weight based upon the total weight of said polymer and said additive.
8. A flame retardant polymeric composition according to Claim 6 wherein said flame retardant additive is present in an amount of about 25 to 35 percent by weight based upon the weight of said polymer and said additive.
9. A flame retardant polymeric composition according to Claim 6 wherein said tris (hydroxyalkyl) isocyanurate is tris (2-hydroxyethyl) isocyanurate and said ammonium phosphate is ammonium polyphosphate.
10. A flame retardant polymeric composition according to Claim g wherein said flame retardant additive contains from about 5 to 40 percent by weight of a blowing agent.
11. A flame retardant polymeric composition according to Claim 10 which contains at least one blowing agent selected from urea, melamine, guanidine, dicyandiamine, butyl urea, glycine, benzene sulfonyl hydrazine, chlorinated paraffin, cyanuric acid, benzoguanamine, melamine cyanurate, hydroxyalkyl-amino-s-triazine, melamine borate, melamine phosphate or melamine sulfate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US30766889A | 1989-02-07 | 1989-02-07 | |
| US307,668 | 1989-02-07 |
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| Publication Number | Publication Date |
|---|---|
| CA2007510A1 true CA2007510A1 (en) | 1990-08-07 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2007510 Abandoned CA2007510A1 (en) | 1989-02-07 | 1990-01-10 | Intumescent flame retardant systems |
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| CA (1) | CA2007510A1 (en) |
| WO (1) | WO1990009418A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117214376A (en) * | 2023-10-27 | 2023-12-12 | 清远市一丞阻燃材料有限公司 | Method for testing flame-retardant effect of phosphorus-containing intumescent flame-retardant particles |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU3708593A (en) * | 1992-04-29 | 1993-11-04 | Avco Corporation | Fire resistive coating |
| BE1006736A3 (en) * | 1993-02-05 | 1994-11-29 | Dsm Nv | Polyamide compound |
| US5414031A (en) * | 1993-11-19 | 1995-05-09 | Polymer Product Company, Inc. | Intumescent nonhalogenated flame retardant polystyrene composition |
| EP0906639A2 (en) * | 1996-05-28 | 1999-04-07 | Gitto/Global Corporation | Flame-retardant battery casing |
| EP2065156A1 (en) * | 2007-11-29 | 2009-06-03 | Nexans | Method for producing a moulded product from polytetrafluorothylene foam |
| EP2325259A1 (en) * | 2009-11-16 | 2011-05-25 | H2V Bvba | Fire retardant for polyurethane foams |
| DE202011110300U1 (en) | 2011-10-31 | 2013-08-05 | Performance Chemicals HGmbH | Reactive oligomers |
| CN111393742A (en) * | 2020-02-28 | 2020-07-10 | 上海金发科技发展有限公司 | Environment-friendly flame-retardant polypropylene-nylon alloy material and preparation method thereof |
| CN111662561B (en) * | 2020-07-13 | 2021-10-01 | 南京林业大学 | Preparation method of flame-retardant and repeatedly-processable wood-plastic composite material |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4355126A (en) * | 1974-12-06 | 1982-10-19 | General Electric Company | Flame retardant, non-dripping compositions of polyphenylene ether and acrylonitrile-butadiene-styrene |
| IT1060705B (en) * | 1976-05-28 | 1982-08-20 | Montedison Spa | SELF-EXTINGUISHING POLYMERIC COMPOSITIONS |
| IT1087517B (en) * | 1977-09-14 | 1985-06-04 | Montedison Spa | POLYMERIC COMPOSITIONS |
| US4579894A (en) * | 1984-05-10 | 1986-04-01 | Montedison S.P.A. | Self-extinguishing polyolefinic compositions having improved flame resistance characteristics and a high thermal stability |
| US4826900A (en) * | 1988-03-31 | 1989-05-02 | The Dow Chemical Company | Ignition resistant modified carbonate polymer composition |
-
1990
- 1990-01-10 CA CA 2007510 patent/CA2007510A1/en not_active Abandoned
- 1990-01-24 WO PCT/US1990/000473 patent/WO1990009418A1/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117214376A (en) * | 2023-10-27 | 2023-12-12 | 清远市一丞阻燃材料有限公司 | Method for testing flame-retardant effect of phosphorus-containing intumescent flame-retardant particles |
Also Published As
| Publication number | Publication date |
|---|---|
| WO1990009418A1 (en) | 1990-08-23 |
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