THERMOPLASTIC POLYURETHANE ADDITIVES FOR IMPROVED POLYMER MATRIX COMPOSITES AND METHODS OF MAKING AND
USING THEREFOR
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority upon United States provisional application serial no. 60/057,894, filed September 4, 1997, the contents of which are herein incorporated in their entirety by this reference.
FIELD OF THE INVENTION
The present invention relates to polymer matrix composites composed of a polymer, a thermoplastic polyurethane, and a reinforcing fiber and articles made from the composites of the present invention.
BACKGROUND OF THE INVENTION
The prior art discloses compounding polymers with a fiber (e.g. glass or carbon) or other polymers to produce a reinforced composite The object of producing the reinforced composite is to increase or enhance the physical properties of the composite. In particular, increasing the thermal and hydrolytic stability of the composite would be advantageous.
The prior art discloses the combination of polyurethanes and polymers in order to increase the mechanical properties of the resultant blend U.S. Patent No 5.519,094 to Tseng et al. and U.S. Patent No. 5,258 ,445 to Sperk ei al. disclose the combination of a thermoplastic polyurethane, a polyester, and a glass fiber to produce a molding composition. International Patent No WO 95/26432 to Wagner el al. disclose the preparation of an abrasion resistant polyester blend composed of a thermoplastic
polyester, a thermoplastic polyurethane, and optionally, nonpolymeπc additives that exhibits improved processing safety. Canadian Patent No. 1 ,1 1 1 ,984 (hereafter CA ' 1 1 1) discloses a poly(butylene terephthalate)/polyurethane molding composition Tseng et al, Sperk et al., Wagner et al., and CA ' 1 1 1 teach one of ordinary skill in the art to use a higher amounts of polyurethane in order to increase or enhance the mechanical properties of the blend
In light of the above it would be very desirable to produce a polymer composite that possesses increased hydrolytic and thermal stability, mechanical strength, and ductility Moreover, it would be advantageous to produce a polymer composite that requires smaller amounts of polyurethane while possessing superior physical properties
SUMMARY OF THE INVENTION
In accordance with the purρose(s) of this invention, as embodied and broadly descπbed herein, this invention, in one aspect, relates to a composite made by the process compπsing melt mixing
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 30 to 90% by weight of the composite,
(b) a thermoplastic polyurethane at from 0 1 to less than 10% by weight of the composite, and
(c) a reinforcing fiber at from 9 9 to 60% by weight of the composite,
wherein the sum of the weight percentages of components (a)-(c) is equal to 100% wherein the polymer (a) is not a polyainide
The invention further relates to a composite prepared by the process comprising melt mixing
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 25 to 90% by weight of the composite;
(b) a thermoplastic polyurethane at from 0 1 to 10% by weight of the composite;
(c) a reinforcing fiber at from 9.8 to 60% by weight of the composite, and
(d) an epoxy compound at from 0.1 to 5% by weight of the composite.
wherein the sum of the weight percentages of components (a)-(d) is equal to 100%.
The invention further relates to a composite prepared by the process comprising melt mixing
(a) a polyester or a liquid crystalline polymer,
(b) a thermoplastic polyurethane at from 0 1 to 10% by weight of the composite, and
(c) a reinforcing fiber,
wherein the sum of the weight percentages of components (a)-(c) is equal to 100%
The
ention further relates to a composite comprising
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 30 to 90% by weight of the composite;
(b) a thermoplastic polyurethane at from 0.1 to less than 10% by weight of the composite; and
(c) a reinforcing fiber at from 9.9 to 60% by weight of the composite,
wherein the sum of the weight percentages of components (a)-(c) is equal to 100 %, wherein the polymer (a) is not a polyamide
The invention further relates to a composite compπsing
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 25 to 90% by weight of the composite;
(b) a thermoplastic polyurethane at from 0.1 to 10% by weight of the composite;
(c) a reinforcing fiber at from 9.8 to 60% by weight of the composite, and
(d) an epoxy compound at from 0.1 to 5% by weight of the composite,
wherein the sum of the weight percentages of components (a)-(d) is equal to 100%.
The invention further relates to a method for making a composite, comprising melt mixing
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 30 to 90% by weight of the composite;
(b) a thermoplastic polyurethane at from 0.1 to less than 10% by weight of the composite; and
c) a reinforcing fiber at from 9.9 to 60% by w eight of the composite,
wherein the sum of the weight percentages of components (a)-(c) is equal to 100 %, wherein the polymer (a) is not a polyamide.
The invention further relates to a method for making a composite, comprising melt mixing
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 25 to 90% by weight of the composite:
(b) a thermoplastic polyurethane at from 0.1 to 10% by weight of the composite;
(c) a reinforcing fiber at from 9.8 to 60% by weight of the composite, and
(d) an epoxy compound at from 0.1 to 5% by weight of the composite,
wherein the sum of the weight percentages of components (a)-(d) is equal to
100%.
Additional advantages of the invention will be set forth in part the description which follow s, and in part will be obvious from the description, or may be learned b\ practice of tne invention The advantages of the invention w ill be realized and attained
by means of the elements and combinations particularly pointed out in the appended claims It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
DETAILED DESCRIPTION OF THE INVENTION
The present invention may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the Examples included therein
Before the present compositions of matter and methods are disclosed and descnbed, it is to be understood that this invention is not limited to specific synthetic methods or to particular formulations, as such may, of course, vary It is also to be understood that the terminology used herein is for the purpose of descπbing particular embodiments only and is not intended to be limiting
In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings
The singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise.
"Optional" or "optionally" means that the subsequently described event oi circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not
The term "isocyanate reactive group" is any group thai can react w ith an isocyanate moiety as shown in Equation I Examples of
reactn e gioups include, but are not limited to hydroxvl groups, amino groups, carbonate gioups oi
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carboxyl groups.
A "carbonyl compound" is any carboxyhc acid, ester, acid halide, or anhydrid
The term "dicarbonyl compound" is any dicarboxylic acid, diester, diacid halide, or dianhydride.
The term "glycol" is any compound that possesses at least two hydroxyl groups Additionally, a glycol can be any precursor compound that is readily converted to a compound possessing two hydroxyl groups. An example of such a compound is hydroquinone (I), which can be converted to biphenol (II) using techniques known in the art.
In accordance with the purposc(s) of this invention, as embodied and broadly described herein, this invention, in one aspect, relates to a composite made by the
process comprising melt mixing
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 30 to 90% by weight of the composite;
(b) a theπnoplastic polyurethane at from 0.1 to less than 10% by weight of the composite; and
(c) a reinforcing fiber at from 9.9 to 60% by weight of the composite,
wherein the sum of the weight percentages of components (a)-(c) is equal to 100%, wherein the polymer (a) is not a polyamide
The invention further relates to a composite prepared by the process comprising melt mixing
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 25 to 90% by weight of the composite;
(b) a thermoplastic polyurethane at from 0.1 to 10% by weight of the composite;
(c) a reinforcing fiber at from 9.8 to 60% by weight of the composite, and
(d) an epoxy compound at from 0.1 to 5% by weight of the composite,
wherein the sum of the weight percentages of components (a)-(d) is equal to 100%
The invention further relates to a composite prepared b> the piocess comprising
melt mixing
(a) a polyester or a liquid crystalline polymer,
(b) a theπnoplastic polyurethane at fiom 0 1 to 10% by weight of the composite, and
(c) a reinforcing fiber,
wherein the sum of the weight percentages of components (a)-(c) is equal to
100%
The invention further relates to a composite comprising
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 30 to 90% by weight of the composite,
(b) a thermoplastic polyurethane at from 0 1 to less than 10% by weight of the composite, and
(c) a reinforcing fiber at from 9 9 to 60% by weight of the composite,
wherein the sum of the weight percentages of components (a)-(c) is equal to 100 %, wheiein the polymer (a) is not a polyamide
The invention further relates to a composite comprising
(a) a polymer having at least one isocyanate reactive group, wheiein the polymer is from 25 to 90% by weight of the composite,
(b) a thermoplastic polyurethane at from 0.1 to 10% by weight of the composite;
(c) a reinforcing fiber at from 9 8 to 60% by weight of the composite, and
(d) an epoxy compound at from 0 1 to 5% by weight of the composite,
wherein the sum of the weight percentages of components (a)-(d) is equal to 100%
The polymer used in the present invention has at least one isocyanate reactive group. The role of the isocyanate reactive group with respect to producing a polymer composite will be discussed below. In one embodiment, the polymer comprises a polyester, a liquid crystalline polymer, a polyamide, a polycarbonate, or a combination thereof.
In one embodiment, the polymer compπses a polyester Polyesters useful m the present invention compnse the reaction product between at least one first glycol component compπsing an aliphatic glycol, a cycloahphatic glycol, an aromatic glycol, or a combination thereof, and at least one first dicarbonyl component comprising an aliphatic dicarbonyl compound, a cycloahphatic dicarbonyl compound, an aromatic dicarbonyl compound, or a combination thereof
In one embodiment, the first glycol component compnses a first glycol compound comprising ethylene glycol, propylene glycol, 1 ,3-propanedιol, 1 ,4- butanediol, 1 ,6-hexanedιol, 1 ,8-octanedιol, 1,10-decanedιol, 2,2-dιmethyl-l ,3- propanediol, 1 ,4-cyclohexanedιmethanol, diethylene glycol, polyethylene glycol, polypropylene glycol; polytelramethylene glycol, or a combination thci eol In one embodiment, the first glycol compound compπses ethylene glycol, 1 ,3-pιopanedιol, 1 ,4-butanedιol, or 1 ,4-cyclohexanedιmethanol In another embodiment, the fust glycol
compound has from 2 to 10 carbon atoms. In another embodiment, the first glycol component further comprises a second glycol compound, wherein the second glycol compound comprises glycerol, trimethyolpropane, pentaerythritol, or a combination thereof. In this embodiment, the second glycol component behaves as a branching agent, which forms branches off the polymer backbone
Examples of first dicarbonyl compounds that can react with the glycol component to produce the polyester include, but are not limited to, terephlhahc acid. isophthalic acid, naphthalenedicarboxyhc acid, cyclohexanedicarboxyhc acid, or a combination thereof. In one embodiment, the first dicarbonyl component comprises terephthalic acid, cyclohexanedicarboxyhc acid, or naphthalenedicarboxyhc acid. Any of the isomers of naphthalenedicarboxyhc acid and cyclohexanedicarboxyhc acid are useful in the present invention. For example, the as-, trans-, or cisl trans isomers of cyclohexanedicarboxyhc acid can be used. In one embodiment, the 2,6-isomer of naphthalenedicarboxylic acid can be used.
In another embodiment, the polyester further compπses the reaction product of a second dicarbonyl compound comprising a C4 to C40 dicarbonyl compound. The second dicarbonyl is a modifying dibasic acid. In one embodiment, the second dicarbonyl compound comprises succinic acid, glutaπc acid, adipic acid, sebacic acid, dimer acid, or a combination thereof.
In another embodiment, the first dicarbonyl component further comprises a third dicarbonyl compound, wherein the third dicarbonyl compound comprises trimellitic acid, trimellitic anhydride, pyromelhtic anhydride, or a combination thereof. The thud dicarbonyl compound can also behave as a branching agent as described above
In one embodiment, the first dicarbonyl component comprises at least 40 mole % of the first dicarbonyl compound, wherein the sum of the dicarbonyl compounds ol the first dicarbonyl component equals 100 mole %
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In one embodiment, the polyester has an inherent viscosity of from 0.2 to 1.5 dL/g, preferably from 0.3 to 1.2 dL/g as determined in 60/40 phenol/tetrachloroethane. Examples of polyesters useful in the present invention include, but are not limited to, poly(butylene terephthalate), poly(propylene terephthalate), poly(ethylene terephthalate), poly(ethylene naphthalate), poly(cyclohexanedimethylene terephthalate), or a combination thereof. In a preferred embodiment, the polyester is poly(ethylene terephthalate) or poly(butylene terephthalate).
In another embodiment, the polymer comprises a liquid crystalline polymer. Any of the liquid crystalline polymers disclosed in U.S. Patent Nos. 4,169,933 and 4,161,470 are useful in the present invention, and are hereby incorporated by reference in their entirety.
In one embodiment, the liquid crystalline polymer comprises the reaction product between a second glycol component and a first carbonyl component. In one embodiment, the second glycol component compπses hydroquinone, biphenol, cyclohexanedimethanol, or a combination thereof. In one embodiment, the first carbonyl component comprises -hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, p- acyloxybenzoic acid, 2,6-naρhthalenedicarboxylic acid, terephthalic acid, isophthalic acid, or a combination thereof, preferably /?-hydroxybenzoic acid, 2,6- naphthalenedicarboxylic acid, or terephthalic acid. In one embodiment, the liquid crystalline polyester has a molecular weight of from 5,000 to 25,000.
In another embodiment, the polymer compπses a polyamide. Any polyamide disclosed in the art can be used in the present invention. In one embodiment, the polyamide comprises the reaction product between a diamine and a second dicarbonyl component. In one embodiment, the diamine comprises a branched or straight chain aliphatic diamine, an aromatic diamine, or a cycloahphatic diamine. In one embodiment, the diamine comprises H2N(CH2)πNH2, wherein n is from 2 lo 16. In one embodiment, the diamine comprises ethylenediamine, trimethylenediamine,
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13
tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1 ,4- cyclohexanedimethylamine, 2-methyl-l,5-pentamethyIenediamine, or a combination thereof. In one embodiment, the second dicarbonyl component comprises a compound having the formula HO2C-Y-CO2H or the salt or diester thereof, wherein Y has at least two carbon atoms. In another embodiment, the second dicarbonyl component comprises sebacic acid, octadecanedioic acid, suberic acid, azelaic acid, undecanedioic acid, glutaπc acid, pimelic acid, adipic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxyhc acid, cyclohexanedicarboxyhc acid, or a combination thereof. In one embodiment, the second dicarbonyl component comprises adipic acid.
In another embodiment, the polyamide comprises the self-condensation product of an amino carboxylic acid. In one embodiment, the amino carboxylic acid has from 2 to 16 carbon atoms between the amino group and the carboxylic acid group. In one embodiment, the amino carboxylic acid comprises 3-amino benzoic acid, 4-amino benzoic acid, or a combination thereof
Any lactam known in the art can be used in the present invention. In one embodiment, the polyamide comprises the self-condensation product of a lactam. In one embodiment, the lactam comprises ε-aminocaproic acid, butyrolactam, pivalactam, caprolactam, capryllactam, enantholactam, undecolactam, dodecanolactam, or a combination thereof. In one embodiment, the lactam comprises caprolactam.
In one embodiment, the polyamide comprises the self-condensation product of caprolactam (NYLON 6""); the reaction product between adipic acid and hexamethylenediamine (NYLON 66®); or the reaction product between adipic acid and tetramethylenediamine (NYLON 4,6*). In another embodiment, the polyamide comprises a polyphthalamide.
A variety of polycarbonates can be used in the present invention. In one embodiment, the polycarbonate comprises bisphenol A polycarbonate.
In one embodiment, the polymer of the present invention is from 50 to 80%o by weight, preferably from 55 to 75%o by weight, more preferably from 60 to 70% by weight of the admixture, wherein the sum of the weight percentages of components (a)- (c) is equal to 100 %.
Any theπnoplastic polyurethane known in the art is useful in the present invention. Examples of theπnoplastic polyurethanes than can be used in the present invention are disclosed in U.S. Patent Nos. 4,822,827; 4,376,834, and 4,567,236, which are incorporated by reference in their entirety The theπnoplastic polyurethanes of the present invention can be both rigid and elastomeπc.
In one embodiment, the theπnoplastic polyurethane compπses the reaction product between a polyisocyanate and a diol component. Examples of polyisocyanates include, but are not limited to, a methylenebιs(phenyl isocyanate), a cycloahphatic diisocyanate, a cyclohexylene diisocyanate, or a combination thereof. In one embodiment, any of the 4,4'-isomer, the 2,4'-ιsomer, or combinations thereof of methylenebιs(phenyl isocyanate) can be used. Examples of other methylenebιs(phen l isocyanates) include, but are not limited to, m- and ?-ρhenylene diisocyanates, chlorophenylene diisocyanates; α, α'-xylylene diisocyanate; 2,4- and 2,6-toluene diisocyanate and mixtures of these latter two isomers, toluidine diisocyanate, hexamethylene diisocyanate; 1 ,5-naphthalene diisocyanate, or isophorone diisocyanate
In one embodiment, the methylenebis(cyclohexyl isocyanate) is the 4,4'-ιsomer. the 2,4'-ιsomer and mixtures thereof Any of the geometric isomers including trans/trans, as/trans, cis/cis and mixtures thereof can be used. Examples of cycloahphatic diisocyanates include, but are not limited to, cyclohexylene diisocyanates
(1 ,2-; 1 ,3-; or 1 ,4-), l -methyl-2,5-cyclohe\ylene diisocyanate,
1 -methyl-2,4-cyclohexylene diisocyanate. 1 -methyl-2,6-cyclohexylcne diisocyanate.
4,4'-ιsopropyhdenebιs(cycIohexyl isocyanate), oi 4,4'-dnsocyanatodicyclohcxyl
In another embodiment, the isocyanate is a modified form of ethylenebisφhenyl isocyanate). These isocyanates have been reacted with an aliphatic glycol or a mixture of aliphatic glycols, such as described in U.S. Pat Nos 3,394,164. 3,644,457, 3,883,571 ; 4,031,026, 4,1 15,429, 4,1 18,41 1 , and 4,299,347, hich are hereby incoφorated by reference in their entirety
In one embodiment, the diol component compnses at least one cycloahphatic diol and at least one diol extender. In one embodiment, the cycloahphatic diol comprises 1 ,3-cycIobutanedιol, 1 ,3-cyclopentanedιol, 1 ,2-cyclohexanedιol, 1,3-cyclohexanedιol, 1 ,4-cyclohexanedιol, 2-cyclohexene-l ,4-dιol,
2-methyl-l ,4-cyclohexanedιol, 2-ethyl-l,4-cyclohexanedιol, 1 ,3-cycloheptanedιol, 1 ,4-cycloheptanedιol, 2-methyl-l ,4-cycloheptanedιol, 4-methyl-l,3-cycloheptanedιol, 1 ,3-cyclooctanedιol, 1,4-cyclooctanedιol, 1,5-cyclooctanedιol, 5-methyl-l,4-cyclooctanedιol, 5-ethyl-l,4-cyclooctanedιol, 5-propyl-l ,4-cyclooctanedιol, 5-butyl-l,4-cyclooctanedιol, 5-hexyl- 1 ,4-cycIooctanedιol, 5-heptyl- 1 ,4-cyclooctanedιol , 5-octyl-l,4-cyclooctanedιol, 4,4'-methylenebιs(cyclohexanol),
4,4'-methylenebιs(2-methylcyclohexanol), 4,4'-methylenebιs(3-methylcyclohexanol), 3,3'-melhylenebιs(cyclohexanol), 4,4'-ethylenebιs(cyclohexanol), 4,4'-propylenebιs(cyclohexanol), 4,4'-butylenebιs(cyclohexanol),
4,4'-ιsopropyhdenebιs(cycIohexanol), 4,4'-ιsobutylenebιs(cyclohexanol), 4,4'-dιhydroxydιcyclohexyl, 4,4'-carbonylbιs(cyclohexanol), 3,3'-carbonylbιs(cyclohexanol), 4,4'-sulfonylbιs(cycIohexanol),
or a combination thereof
In one embodiment, the diol extender comprises ethylene glycol, 1 ,3-propanedιol, 1 ,4-butanedιol, 1 ,5-pentanedιol. 1 ,6-hexanedιol, 1 ,2-pιopancdιol, 1 ,3-butanedιol, 2,3-butanedιol, 1 ,3-pentanedιol, l ,2-he\anedιol, 3-methylpenιane-l,5-dιol, 1 ,9-nonanedιol, 2-methyloctane- l ,8-dιol, 1 ,4-cyclohexanedιmethanol, hydroquinone bιs(h\ dro\vethyl)elheι , diethylcne glyco 1
dipropylene glycol; tπpropylene glycol; ethanolamine, N-methyl-diethanolamine, N-ethyldiethanolamine, or a combination thereof
In one embodiment, diol component can be an ester diol formed by esteπfying an aliphatic dicarboxylic acid with an aliphatic diol listed above Examples of aliphatic dicarboxylic acids include, but are not limited to, adipic acid, azelaic, acid, or glutaπc acid In one embodiment, from about 0 01 to about 0 8 mole of dicarboxylic acid per mole of diol are reacted to produce the ester diol
In one embodiment, the diol component is the reaction product between an aliphatic diol or tπol and a lactone In one embodiment, 0 01 to 2 moles of lactone per mole of diol or tπol are reacted with one another to produce the diol component Examples of aliphatic diols in this embodiment include, but are not limited to, 1 ,4-cyclohexanedιmethanol, neopentyl glycol, hexane-l ,6-dιol, ethylene glycol, butane- 1 ,4-dιol, or tπmethylolpropane Examples of aliphatic tπols include, but are not limited to, glycerol or tπmethylolpropane In one embodiment, the lactone is epsilon- caprolactone
In one embodiment, the cycloahphatic diol is from 10 to 90% by weight of the diol component and the diol extender is from 10 to 90% by weight of the diol component, wherein the sum of the weight percentages of the cycloahphatic diol and diol extender is equal to 100%
In another embodiment, a polyol is used to prepare the theπnoplastic polyurethane Examples of polyols include, but are not limited to, a polyether polyol, a polyester polyol, a hydroxy-teπninated polycarbonate, a hydroxy-teπ nated polybutadiene a hydroxy-terminated polybutadiene-acrylonitπle copolymcr, a hydroxy-terminated copolymer of a dialkyl siloxane and alkylene oxide, or a combination thereof In one embodiment, the molecular weight of the polyol is from about 1 .250 to about 10,000, preferably, from about 2 000 to about 8.000
Examples of polyether polyols include, but are not limited to, polyoxyethylene glycol or polyoxypropylene glycol In one embodiment, polyoxyethylene glycol or polyoxypropylene glycol can be capped with 1) ethylene oxide residues, 2) random and block copolymers of ethylene oxide and propylene oxide, 3) propoxylated tπ- and tetrahydπc alcohols such as glycerine, tπmethylolpropane, or pentaerythπtol, 4) polytetramethylene glycol, or 5) random and block copolymers of tetrahydrofuran and ethylene oxide and/or propylene oxide In one embodiment, the polyether polyol is a random and block copolymer of ethylene and propylene oxide or polytetramethylene glycol Other examples of polyether polyols useful in the present invention include, but are not limited to vinyl reinforced polyether polyols, such as the polymeπzation product between styrene and/or acrylonitπle and the polyether polyol
In one embodiment, a polyether ester can be prepared by reacting a polyether polyol descπbed above with a di- or tnfunctional aliphatic or aromatic carboxylic acid Examples of useful carboxylic acids include, but are not limited to, adipic acid, azelaic acid, glutaπc acid, isophthahc acid, terephthalic acid, or tπmelhtic acid In one embodiment, the polyester polyol is the polymeπzation product between epsilon-caprolactone and ethylene glycol or ethanolamine In one embodiment, the polyester polyol is prepared by the esteπfication of a polycarboxyhc acid such as phthahc acid, terephthalic acid, succinic acid, glutaπc acid, adipic acid, or azelaic acid and with a polyhydπc alcohol such as ethylene glycol, butanediol, glycerol, tπmethylolpropane, 1 ,2,6-hexanetπol, or cyclohexanedimethanol and the like In one embodiment, the polyester polyol is prepared b) esteπfying a dimenc or trimcπc
acid, optionally mixed with a monomeπc fatty acid such as oleic acid, with a long chain aliphatic diol such as hexane-l ,6-dιol
In one embodiment, a polyether diamine useful in the present invention is JEFFAM1NE* . which is manufacluied by lefferson Chemical Compam
In one embodiment, polycarbonates used to make the thermoplastic polyurethanes of the present invention containing hydroxyl groups useful in the present invention are prepared by reacting a diol, such as propane- 1 ,3-diol, butane-l ,4-diol, hexan- l ,6-diol, diethylene glycol, triethylene glycol, or dipropylene glycol, with a diarylcarbonate (e.g. diphenylcarbonate) or with phosgene.
In one embodiment, silicon-containing polyethers useful in the present invention are copolymers of alkylene oxides with dialkylsiloxanes such as dimethylsiloxane. The silicon-containing polyethers disclosed in U.S. Pat. No. 4,057,595, which is hereby incoφorated by reference in its entirety, can be used in the present invention.
In one embodiment, hydroxy-terminated poly-butadiene copolymers sold under the tradename POLY BD® Liquid Resins manufactured by Arco Chemical Company are useful in the present invention. In one embodiment, hydroxy- and amine-terminated butadiene/acrylonitrile copolymers sold under the tradename HYCAR® hydroxyl-terminated (HT) Liquid Polymers and amine-terminated (AT) Liquid Polymers, respectively, can be used in the present invention.
In one embodiment, the thermoplastic polyurethane is ISOPLAST®, which is manufactured by the Dow Chemical Company. There are a number of different thermoplastic polyurethanes sold under the tradename ISOPLAST®; however, these theπnoplastic polyurethanes are typically the reaction product between methylenebis(phenyl isocyanate) and a number of different glycols. In one embodiment, the themioplastic polyurethane is ISOPLAST® 301 , which is the reaction product between methylenebis(phenyl isocyanate), 1 ,6-hexanediol, cyclohexanedimelhanol, and polytetramethylene glycol.
In one embodiment, the theπnoplastic polyurethane is from 1 to 10%. preferably from 1 to 9%, more preferably from 1 to S%, more preferably from 1 to 7%.
more preferably from 1 to 6%, more preferably from 1 to 5%, more preferably from 1 to 4%, more preferably from 1 to 3%, more preferably from 1 to 2%, or even more preferably from 1 to 1.5% by weight of the mixture, wherein the sum of the weight percentages of components (a)-(c) is equal to 100 %.
One advantage of the present invention is that only a small amount of theπnoplastic polyurethane is required to produce a composite with superior physical properties. Moreover, by using higher amounts of thermoplastic polyurethane, which is disclosed in the pπor art, the viscosity of the resultant composite also increases. The higher the viscosity, the more difficult it is to extrude the composite. The present invention avoids these processing problems by using only a small amount of thermoplastic polyurethane.
Any reinforcing fiber known in the art can be used in the present invention. Examples of reinforcing fibers include, but are not limited to, a glass fiber or carbon fiber. In one embodiment, the reinforcing fiber comprises a glass fiber that has been sized. Sizing involves the application of a coupling agent and a film former on the surface of the fiber. In one embodiment, the coupling agent is a functional silane compound and the film former is an epoxy resin or polyurethane. The surface treatment on the glass fiber should promote good adhesion between the glass fiber and the polymer. In one embodiment, the glass fiber compπses PPG 3540, which is a polyurethane sized glass fiber manufactured by PPG Industries, Inc.
In one embodiment, when the reinforcing fiber comprises a glass fiber, the amount of glass fiber used is from 9.9 to 60% by weight, preferably from 15 to 45% by weight of the mixture.
In one embodiment, the polyester is poly(butylene terephthalate), the thermoplastic polyurethane is ISOPLAST* 301. and the reinforcing fiber is PPG 354( >
Other components can be used to prepare the polymer composite of the present invention. In one embodiment, an epoxy compound can be used. When an epoxy compound is used in combination with the polymer having at least one isocyanate rective group, the thermoplastic polyurethane, and the reinforcing fiber, the resultant polymer composite possesses enhanced or increased strength and aging characteristics.
In one embodiment, the epoxy compound comprises the reaction product of a phenolic compound and epichlorohydrin to produce a primary epoxide. The phenolic compounds that can be derivatized are known in the art. In one embodiment, the phenolic compound is bisphenol A. In one embodiment, the epoxy compound is XD 9053.01 , which is manufactured by the Dow Chemical company. XD 9053.01 comprises (tris-hydroxy phenyl)methane that has been deπvatized to form the triglycidyl ether that has been partially oligomeπzed. In one embodiment, the epoxy compound is from 0.1 to 5% by weight, preferably from 0.1 to 2%o by weight, more preferably from 0.25 to 2% by weight of the mixture, wherein the sum of the weight percentages of components (a)-(c) and the epoxy stabilizer is equal to 100 %.
Other additives known in the art can be added to the polymer composite. Examples of additives include, but are not limited to, a colorant, a filler, a processing aid, a plasticizer, a nucleating compound, a stabilizer, an antioxidant, a mold release agent, a flame retardant, a reinforcing agent, or a combination thereof. In one embodiment, the reinforcing agent comprises calcium carbonate, talc, iron oxide, mica, monlinorillonile, clay, or a combination thereof
The invention further relates to a method for making a composite, comprising melt mixing
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 30 to 90% by weight of the composite;
(b) a thermoplastic polyurethane at from 0.1 to less than 10%> by weight of the composite; and
c) a reinforcing fiber at from 9 9 to 60% by weight of the composite,
wherein the sum of the weight percentages of components (a)-(c) is equal to 100 %, wherein the polymer (a) is not a polyamide
The invention further relates to a method for making a composite, comprising melt mixing
(a) a polymer having at least one isocyanate reactive group, wherein the polymer is from 25 to 90% by weight of the composite,
(b) a thermoplastic polyurethane at from 0 1 to 10% by weight of the composite,
(c) a reinforcing fiber at from 9 8 to 60% b> weight of the composite, and
(d) an epoxy compound at from 0 1 to 5% b> eight of the composite,
wherein the sum of the weight percentages of components (a)-(d) is equal to 100%
The polymer, themioplastic polyurethane, and reinfoicing fiber can be melt mixed using a variety of techniques know n in the art In one embodiment, the polymei composite can be produced by a Brabendei Plastograph, Haake plaslograph melt mixei (Rhcocord 90), a single screw exti uder, or a iw in screw exti udei (such as Wci nci Pfleiderer equipment)
Not wishing to be bound by theory, it is believed that during melt mixing, the thermoplastic polyurethane depolymerizes to produce an isocyanate intennediate in situ. The polymer, which has at least one isocyanate reactive group, reacts with the isocyanate intermediate. This ultimately results in chain extension, which increases the molecular weight of the polymer. Additionally, the thermoplastic polyurethane and/or the isocyanate intennediate can react with the reinforcing fiber, which improves the interfacial adhesion between the thermoplastic polyurethane and the reinforcing fiber. The combination of the polymer of the present invention, theπnoplastic polyurethane, and reinforcing fiber results in the formation of a polymer composite with increased thermal and hydrolytic stability as well as increased mechanical properties such as tensile strength and ductility.
Any of the polymer composites of the present invention can be melt processed and extruded as pellets or chips. The polymer composites can also be molded or shaped to produce a desired article by using extrusion, pultrusion, injection molding, or compression molding techniques.
EXAMPLES
The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compositions of matter claimed herein are made and evaluated, and are intended to be purely exemplary of the invention and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some eπors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at room temperature and pressure is at or near atmospheric.
General Considerations
All of the following examples were prepared using poly(butylene terephthalate) (PBT) having a molecular weight in the range of from 14,000 to 20,000 as determined by gel peπneation chromatography against poly(ethylene terephthalate) standards. The theπnoplastic polyurethane utilized in these examples is commercially available from Dow Chemical as ISOPLAST® 301. The giass fiber used in the examples was PPG 3540. The PBT and glass blends were prepared by mixing on a twin screw extruder with a set point of 240 °C. The epoxy compound used in the examples was Dow XD 9053.01 , and was melt mixed with components (a), (b), and/or (c). The examples were extruded into a cold water bath and pelletized. All compositions are reported on a weight % basis. All formulations contain 2.25 wt % "additives" which consist of antioxidants, stabilizers and processing aids. Mechanical properties were evaluated on injection molded specimens following ASTM methods. Hydrolytic stability was evaluated as a % of tensile strength retained compared to the as molded properties after aging at 100 °C, 100 % relative humidity for 14 days. Thermal stability was evaluated as a % of tensile strength retained compared to the as molded properties after aging at 190 °C for 500 hours.
Examples 1 -ή
Example 1 is a comparative example that does not contain the themioplastic polyurethane additive of this invention or the epoxy compound. Examples 2 and 3 are representative examples of this invention containing 1.5 and 3 wt% of the themioplastic polyurethane respectively. As can be seen from the Table 1 the strength properties of these foπnulations have increased significantly as compared to the control Example 1 . It should also be noted that the % tensile strength retained after both hydrolytic and thennal aging also increased as compared to Example 1.
Example 4 is a glass fiber reinforced PBT comparative example that contains
only an epoxy compound as is common to the art. Examples 5 and 6 are examples of this invention showing the synergistic effect of adding both the epoxy stabilizer as well as the thermoplastic polyurethane of this invention. As can be seen from the data, the addition of theπnoplastic polyurethane to the polyester with the epoxy results in further increases in the strength and ductility of the composite as well as even further improved hydrolytic and thermal stability.
Table 1: Mechanical Properties of Glass Fiber Reinforced Polyesters
Too Brittle to Tesl (sample bioke in the grips)
Throughout this application, vaπous publications are referenced The disclosures of these publications in their entireties are hereby incoφorated by reference into this application in order to more fully descπbe the state of the art to which this invention pertains
It will be apparent to those skilled in the art that vaπous modifications and vaπations can be made in the present invention without departing from the scope oi spirit of the invention Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein It is intended that the specification and examples be considered as exemplary onl , with a true scope and spirit of the invention being indicated by the following claims