CA2032187A1

CA2032187A1 - Polycarbonate/copolyetherester composites

Info

Publication number: CA2032187A1
Application number: CA002032187A
Authority: CA
Inventors: Harold Frazee Giles, Jr.; James Russell Irish; William Joseph Mcnally
Original assignee: Individual
Current assignee: General Electric Co
Priority date: 1990-01-03
Filing date: 1990-12-13
Publication date: 1991-07-04
Also published as: DE4041808A1; JPH0662789B2; JPH04356531A

Abstract

POLYCARBONATE/COPOYETHERESTER COMPOSITES
ABSTRACT OF THE DISCLOSURE
Polycarbonate composites having internal layers of copolyetherester resin exhibit improved flexural modulus. The composites are useful as structural panels.

Description

POLYCARBONATE/COPOLYETHERESTER COMPOSITE~
Harold F. Giles, Jr.
Jamës R. Irish William J. McNally BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to po1ycarbonate composites, and more particularly relates to polycarbonate composites having a layer of a copolyetherester resin.
Descrlptlon of Related Art 5Composites of polycarbonate resin reinforced with glass mat are known, and can be made by compressing together under heat and pressure alternating layers of polycarbonate resin film and glass mat.
While the composites are suitable for use as structural panels, in many applications it may be desirous ~o have enhanced levels of flexural modulus.
Accordingly, one object of the present invention is to provide polycarbonate composites exhibiting enhanced levels of flexural modulus.
SUMMARY O~ THE INVENTION
The present invention involves a polycarbonate resin composite obtained from compressi on melt laminating layers of polycarbonate film, glass fiber 23 mat, and copolyetherester resin film. The composite exhibits improved levels of flexural modulus and is useful as a structural panel.
DETAILED DESCRIPTION OF THE INVENTION
The polycarbonate composi tes have a layer of copolyetherester resin. The preferred composite is 25 made by melt laminating a layup of 10 mils bisphenol-A polycarbonate resin/10 mils bisphenol-A

2~2~g~

polycarbonate resin film/random glass fiber mat having a density of 2 ounces per square foot/ 20 mils film of copolyetherester resin/random glass fiber mat having a density of 2 ounces per square foot/10 mils bisphenol-A polycarbonate film/10 mils bisphenol-A polycarbonate film.
The polycarbonate resins suitable for use in the composites include high molecular weight, ther~oplastic, aromatic polycarbonates such as homopolycarbonates and copolycarbonates and mixtures thereof which have average molecular weights of about 8,000 to more than 200,000, preferably of about 20,000 to 80,000 and an I.V. of 0.40 to 1.0 dl/g as measured in methylene chloride at 25C.
These polycarbonates are derived from dihydric phenols such as, for example, 2,2-bis(4-hydroxy-phenyl)propane, bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 4,4-bis(4-hydroxyphenyl)heptane, 2,2-(3,5,3',5'-tetrachloro-4,4'-dihydroxyphenyl)propane, 2,2-(3,-5,3',5'-tetrabromo-4,4'-dihydroxydiphenyl)propane, and (3,3'-dichloro-4,4'-dihydroxydiphenyl)methane.
Other dihydric phenols which are also suitable for use in the preparation of the above polycarbonates are disclosed in U.S. Pa~ent Nos. 2,999,835;

3,028,365; 3,334,154; and 4,131,57~.
These aromatic polycarbonates can be manufactured by known processes, such as, for example, by reac~ing a dihydric phenol with a 30 carbonate precursor such as phcsgene in accordance with methods set forth in the above-cited literature and U.S. Pa~ent Nos. 4,018,750 and 4,123,436, or by transesterification processes such as are disclosed in U.S. Patent No. 3,153,008, as well as other 35 processes known to those skilled in the art.

2~32~.~7 The aromatic polycarbonates utilized in the present invention also include the polymeric derivates of a dihydric phenol, a dicarboxylic acid, and carbonic acid, such as are disclosed in U.S.
5Patent No. 3,169,131.
It is also possible to employ two or more different dihydric phenols or a copolymer of a dihydric phenol with a glycol or with hydroxy or acid terminated polyester, or with a dibasic acid in the event a carbonate copolymer or interpolymer rather than a homopolyme~ is desired for use in the preparation of the aromatic polycarbonate utilized in the practice of this invention. Also employed in the practice of this invention can be blends of any of the above materials to provide the aromatic polycarbonate.
Branched polycarbonates, such as are described in U.S. Patent No. 4,001,184, can also be utilized in the practice of this invention, as can blends of a linear polycarbonate and a branched polycarbonate.
Suitable thermoplastic copolyetheresters include both random and block copolymers. In general these are prepared by conventional esterification/polycondensation processes from (a~
25 one or more diols, (b) one or more dicarboxylic acids, (c~ one or more long chain ether glycols, an~
optionally, (d~ one or more caprolac.tones or polycaprolactones.
Diols(a) which can be used in the preparation 30 of the copolyetheresters include both saturated and unsaturated alipha~ic cycloaliphatic dihydroxy compounds as well as aromatic dihydroxy compounds.
These diols are preferably of a low molecular weight, i.e. having a molecular weight of about 300 35 or less. When used herein, the term "diols" and "low molecular weight diols" should be construed to include equivalent ester forming derivatives thereof, provided, however, that the molecular weight requirement pertains to the diol only and not 5 to its derivatives. Exemplary of ester forming derivatives there may be given the acetates of the diols as well as, for example, ethylene oxide or ethylene carbonate for ethylene glycol.
Preferred saturated and unsaturated aliphatic 13 and cycloaliphatic diols are those having from about 2 to 19 carbon atoms. Exemplary of these diols there may be given ethylene glycol; propanediol;
butanediol; pentanediol; 2-methyl propanediol;
2,2-dimethyl propanediol; hexanediol; decanediol;
2-octyl undecanediol; 1,2-, 1,3- and 1,4- dihydroxy cyclohexane; 1,2-, 1,3- and 1,4- cyclohexane dimethanol; butenediol; hexenediol, etc. Especially preferred are 1,4-butanediol and mixtures thereof with hexanediol or butenediol.
Aromatic diols suitable for use in the preparation of the thermoplastic elastomers are generally those having from 6 to about 19 carbon atoms. Included among the aromatic dihydroxy compounds are resorcinol; hydroquinone;
25 1,5 dihydroxy naphthalene; 4,4'-dihydroxy diphenyl;
bis(p-hydroxy phenyl~methane and 2,2-bis(p-hydroxy phenyl)propane.
Especially preferred diols are the saturated aliphatic diols, mixtures thereof and mixtures of a 30 saturated diol(s~ with an unsaturated diol(s), wherein each diol contains from 2 to about 8 carbon atoms. Where more than one diol is employed, it is preferred that at least about 60 mole %, most preferablx at leas~ 80 mole -~, based on the total 35 diol content, be the same diol. As mentioned above, 2 0 3 218 7 ~CT-4275 the preferr~d thermoplastic elastomers are those in which 1,4-butanediol is present in a predominant amount.
Dicarboxylic acids ~b) which are suitable for 5 use in the preparation of the copolyetheresters include aliphatic, cycloaliphatic, and/or aromatic dicarboxylic acids. These acids are preferably of a low molecular weight, i.e., having a molecular weight of less than about 350; howeYer, higher molecular weight dicarboxylic acids, especially dimer acids, may also be used. The term "dicarboxylic acids" as used herein, includes equivalents of dicarboxylic acids having two functional carboxyl groups which perform substantially like dicarboxylic acids in reaction with glycols and diols in forming polyester polymers. These equivalents include esters and ester-forming derivatives, such as acid halides and anhydrides. Additionally, the dicarboxylic acids 20 may contain any substituent group(s) or combinations which do not substantially interfere with the polymer formation and use of the polymer in the practice of this invention.
Aliphatic dicarboxylic acids, as the term is used herein, refers to carboxylic acids having two carboxyl groups each of which is attached to a saturated carbon atom. If the carbon atom to which the carboxyl group is attached is saturated and is in a ring, the acid is cycloaliphatic.
Aromatic dicarboxylic acids, as the term is used herein, are dicarboxylic acids having two carboxyl groups each of which is attached to a carbon atom in an isolated or fused benzene ring system. It is not necessary that both functional 35 carboxyl groups be attached to the same aromatic 2~32~7 8CT-4Z75 ring and where more than one ring is present, they can be joined by aliphatic or aromatic divalent radicals or divalent radicals such as - 0 - or --SO2--.
Representative aliphatic and cycloaliphatic acids which can be used are sebacic acid~
1,2-cyclohexane dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, adipic acid, glutaric acid, succinic acid, oxalic acid, azelaic acid, diethylmalonic acid, allylmalonic acid, dimer acid, 4-cyclohexene-1,2-dicarboxylic acid~ 2-ethylsuberic acid, tetramethylsuccinic acid, cyclopentane dicarboxylic acid, decahydro-1,5-naphthalene 15 dicarboxylic acid, 4,4'-bicyclohexyl dicarboxylic acid, decahydro-2,6-naphthalene dicarboxylic acid, 4,4-methylenebis~cyclohexane carboxylic acid), 3,4-furan dicarboxylic acid, and 1,1-cyclobutane dicarboxylic acid, Preferred aliphatic acids are cyclohexane dicarboxylic acids, sebacic acid, dimer acid, glutaric acid, azelaic acid and adipic acid.
Representative aromatic dicarboxylic acids which can be used include terephthalic, phthalic and isophthalic acids, bi-benzoic acid, substituted dicarboxy compounds with two benzene nuclei such as bis(p-carboxyphenyl) methane, oxybis(benzoic acid~, ethylenel~2-bis-(p-oxybenzoic acid), lr5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 30 phenanthrene dicarboxylic acid, anthracene dicarboxylic acid, 4,4'-sulfonyl dibenzoic acid, and halo and Cl-C12 alkyl, alkoxy, and aryl ring substitution derivatives thereof. Hydroxy acids such as p(~-hydroxyethoxy)benzoic acid can also be used provided an aromatic dicarboxylic acid is also present.
Preferred dicarboxylic acids for the preparation of the polyetheresters are the aromatic 5 dicarboxylic acids, mixtures thereof and mixtures of one or more dicarboxylic acid with an aliphatic and/or cycloaliphatic dicarboxylic acid, most preferably the aromatic dicarboxylic acids. Among the aromatic acids, those with 8~16 carbon atoms are preferred, par~icularly the benzene dicarboxylic acids, i.e., phthalic, terephthalic and isophthalic acids and their dimethyl derivatives. Especially preferred is dimethyl terephthalate.
Finally, where mixtures of dicarboxylic acids are employed, it is preferred that at least about 60 mole %, preferably at least about 8~ mole %, based on 100 mole % of dicarboxylie acid (b) be of the same dicarboxylic acid or ester derivative thereof.
As mentioned above, the preferred copolyetheresters 20 are those in which dimethylterephthalate is the predominant dicarboxylic acid.
Suitable long chain ether glycols (c) which can be used in the preparation of the thermoplastic elastomers are preferably poly(oxyalkylene)glycols 25 and copoly(oxyalkylene)glycols of molecular weight of from about 400 to 1200. Preferred poly(oxyalkylene) units are derived from long chain ether glycols of from about 900 to about 4000 molecular weight and having a carbon-~o-oxygen ratio of from about 1.8 to about 4.3, exclusive of any side chains.
Representative of suitable poly(oxyalkylene)-glycols ~here may be given poly(ethylene ether3-glycol; poly(propylene ether)glycol; poly(tetra-methylene e~her~glycol; random or block copolymers 20~2~7 8CT-4275 of ethylene oxide and propylene oxide, including ethylene oxide and capped poly(propylene ether)-glycol and predominately poly(ethylene ether) backbone, copoly~propylene ether-ethylene ether)-5 glycol; and random or block copolymers oftetrahydrofuran with minor amounts of a second monomer such as ethylene oxide, propylene oxide, or methyltetrahydrofuran (used in proportions such that the carbon-to-oxygen ratio does not exceed about o 4 3). Polyformal glycols prepared by reacting formaldehyde with diols such as 1,4-butanediol and 1,5-pentanediol are also useful. Especially preferred poly(oxyalkylene)glycols are poly-(propylene ether)glycol, poly(tetramethylene ether)glycol and predominately poly(ethylene ether) backbone copoly(propylene ether-e~hylene ether~-glycol.
Optionally, these copolyetheresters may have incorporated therein one or more caprolactones or polycaprolactones.
Caprolactones (d) suitable for use herein are widely available commercially, e.g., Union Carbide Corporation and Aldrich Chemicals. While epsilon caprolactone is especially preferred, it is also 25 possible to use substituted caprolactones wherein the epsilon caprolactone is subs~ituted by a lower alkyl group such as a methyl or ethyl group at the alpha, beta, gamma, delta or epsilon positions.
Additionally, it is possible to use polycapro-30 lactone, including homopolymers and copolymersthereof with one or more components, as well as hydroxy ~erminated polycaprolactone, as block units in the copolyetheresters. Suitable polycapro-lactones and processes for their production are 35 described in, for example, U.S. Patent Nos.

2 ~ 3 2 ~ ~ 7 8CT-4275 _ g _ 3,761,511; 3,767,627, and 3,806,495 herein incorporated by reference.
In general, suitable copolyetherester elastomers (A) are those in which the weight percent 5 of (c) long chain ether glycol component or the combined weight percent of ~c) long chain ether glycol component and (d) caprolactone component in the copolyetherester is from about 5 to about 70 weight percent. Preferred compositions are those wherein the weight percent of (c) or ~c) and (d) is from about `10 to about 50 weight percent. Where both (c) long chain ether glycol and (d) caprolactone are present, each will comprise from about 2 to about 50 percent by weight, preferably 15 from about 5 to about 30 percent by weight, of the copolyetherester.
As described above, the copolyetheresters may be prepared by conventional esterification/-condensation reactions for the production of polyesters. Exemplary of the processes that may be practi ced are as set forth in, for example, U.S.
Patent Nos. 3,023,192; 3,763,109; 3,651,014;
3,663,653 and 3,801,547, herein incorporated by reference. Additionally, these compositions may be 25 prepared by such processes and other known processes to effect random copolymers, block copolymers or hybrids thereof wherein both random and block units are present. For example, it is possible that any two or more of the foregoing monomers/reactants may be prereacted prior to polymerization of the final copolyetheresters. Alternatively, a ~wo part synthesis may be employed wherein two different diols and/or dicarboxylic acids are each prereacted in separated reac~ors to form two low molecular weight prepolymers which are then combined with the 2 ~ 3 218 7 8CT-4275 long chain ether glycol to form the final tri block copolyetherester.
The reinforcing fiber layers are preferably in the form of non-woYen long glass fiber mats.
5 Preferably the glass fiber mat layer has a density of from 0.5 ounce/square foot to 4 ounces/square foot and more preferably 2 ounces/square foot. The glass fiber rein~orcement may also be in various other forms, including chopped glass, glass bundles, and individual glass fibers. Carbon fibers, metal fibers and aramide fibers may be used as reinforcing fibers.
The preferred fiber reinforced composite has outer layers of polycarbonate resin and an inner layer of a copolyetherester resin. More preferably, the composite is made from compressing at elevated temperatures a layup of an outer aromatic polycarbonate resin layer/a glass fiber mat layer/an inner copolyetheres~er resin layer/a glass fiber mat layer/ and an outer aromatic polycarbonate resin layer. The composites can have a total thickness of from 30 mils to 750 mils, preferably from 50 mils to 250 mils. The reinforcing fibers are preferably present at levels of 5 percent by weight ~o 50 25 percent by weight based on the total weight of the composite. The composites are preferably made by compressing the layers under pressures of from 5 pounds per square inch to 100 pounds per square inch, more preferably 10 pounds per square inch to pounds per square inch, at temperatures of preferably between 230C to 400O, more preferably about 280C.
The composites can then be stamped at elevated temperatures to produce structural panels. The copolyetherester resin exhibits good impregnation vf adjacent glass fiber mat.
EX~MPLES
The following examples illustrate the present invention but are not meant to limit the scope 5 thereof.

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Claims

1. A fiber reinforced composite comprising:
(a) a layer of polycarbonate resin; and (b) a layer of copolyetherester resin.

2. A fiber reinforced composite comprising:
(a) a layer of polycarbonate resin;
(b) a layer of copolyetherester resin; and (c) an amount of reinforcing glass fibers.

3. A fiber reinforced composite comprising:
(a) a first outer layer of aromatic polycarbonate resin;
(b) an inner layer of copolyetherester resin;
(c) a second outer layer of aromatic polycarbonate resin, said copolyetherester resin being located between said first and second layers of aromatic polycarbonate resin.

4. The composite of claim 3 wherein said composite is reinforced with a glass fiber mat.

5. The composite of claim 3 wherein said composite is obtained from compressing under heat and pressure a layup comprising an outer layer of polycarbonate film, a first layer of glass fiber mats, an inner layer of copolyetherester film, a second layer of glass fiber mat, a second outer layer of polycarbonate film.

6. The composite of claim 3 wherein said composite has a thickness of from between 30 mils and 750 mils.

7. The composite of claim 3 wherein said composite has a thickness of from between 50 mils and 250 mils.

8. The composite of claim 7 wherein said copolyetherester is derived from the reaction products of (i) at least one diol (ii) at least one dicarboxylic acid, and at least one long chain ether glycol.

9. The composite of claim 8 wherein said aromatic polycarbonate is derived from bisphenol-A and a carbonate precursor.

10. The invention as defined in any of the preceding claims including any further features of novelty disclosed.