CA1262584A - Modified polyester composition - Google Patents
Modified polyester compositionInfo
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- CA1262584A CA1262584A CA000469642A CA469642A CA1262584A CA 1262584 A CA1262584 A CA 1262584A CA 000469642 A CA000469642 A CA 000469642A CA 469642 A CA469642 A CA 469642A CA 1262584 A CA1262584 A CA 1262584A
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Abstract
MODIFIED POLYESTER COMPOSITION
ABSTRACT OF THE DISCLOSURE
New and improved resin mixtures are disclosed comprising an aromatic polyester or copolyester resin;
an aromatic polycarbonate resin, and a modifier combination therefor comprising an acrylate/methacrylate core-shell multiphase composite interpolymer resin and an olefinic resin selected from C1-C10 olefin homo-polymers and copolymers of an olefin and acrylic acid, methacrylic acid, or alkyl esters of such acids. The resin mixtures exhibit retailed impact resistance at room temperature and improved tensile elongation, improved processability, moldability and extrudability.
In a preferred embodiment, the acrylate/methacrylate core shell copolymer resin and the olefinic resin are precompounded to form a modifier concentrate. Pre-compounding reduces the flammability hazards associated with blending rubber powders and avoids worker exposure to chemical dust. In addition, the precompounded composition is more easily and completely dispersed in the other polymeric components providing improved part appearance and better melt flow and permits a reduction in the amount of core-shell interpolymer resin employed without sacrificing important physical properties.
ABSTRACT OF THE DISCLOSURE
New and improved resin mixtures are disclosed comprising an aromatic polyester or copolyester resin;
an aromatic polycarbonate resin, and a modifier combination therefor comprising an acrylate/methacrylate core-shell multiphase composite interpolymer resin and an olefinic resin selected from C1-C10 olefin homo-polymers and copolymers of an olefin and acrylic acid, methacrylic acid, or alkyl esters of such acids. The resin mixtures exhibit retailed impact resistance at room temperature and improved tensile elongation, improved processability, moldability and extrudability.
In a preferred embodiment, the acrylate/methacrylate core shell copolymer resin and the olefinic resin are precompounded to form a modifier concentrate. Pre-compounding reduces the flammability hazards associated with blending rubber powders and avoids worker exposure to chemical dust. In addition, the precompounded composition is more easily and completely dispersed in the other polymeric components providing improved part appearance and better melt flow and permits a reduction in the amount of core-shell interpolymer resin employed without sacrificing important physical properties.
Description
~6~5~3~
-1- 8CU-38~6 MODIFIED POLYESTER C0~5POSITION
BAC:gGROUND OF THE INV~NTION
~ he present invention relates to new and improved thermoplastic polyester compositions character-i.zed by safer handling, improved processability, improvedappearance and by retained resistance to impact failure.
More particularly, it relates to poly(alkylene-terephthalate) polymers and copolymers impact modifiedwith the combinatlon of an aromatic polycarbonate resin and a modifier combination comprising an acrylate/meth-acrylate core-shell graE-t copolymer resin and an olefinic resin selected from polyolefin resins and olefin ~opolymer resins.
High molecular weight linear polyest~rs and copolymers of glycols and terephthalic or isophthalic acid have been avaiIable for a number of years. These are described, inter alia, in Whinfield, et al., U.S.
-1- 8CU-38~6 MODIFIED POLYESTER C0~5POSITION
BAC:gGROUND OF THE INV~NTION
~ he present invention relates to new and improved thermoplastic polyester compositions character-i.zed by safer handling, improved processability, improvedappearance and by retained resistance to impact failure.
More particularly, it relates to poly(alkylene-terephthalate) polymers and copolymers impact modifiedwith the combinatlon of an aromatic polycarbonate resin and a modifier combination comprising an acrylate/meth-acrylate core-shell graE-t copolymer resin and an olefinic resin selected from polyolefin resins and olefin ~opolymer resins.
High molecular weight linear polyest~rs and copolymers of glycols and terephthalic or isophthalic acid have been avaiIable for a number of years. These are described, inter alia, in Whinfield, et al., U.S.
2,465, 319 and in Pengilly, U.S. 3 r 047,539. These patents disclose that the polyesters are particularly advantageous as film and fiber formers.
With the development of molecular weight control, the use of nucleating agents and two-step-molding cycles, polytethylene terephthalate) has become an important constituent of injection moldable compositions.
Poly(1,4-butylene terephthalate), because of its very rapid crystal].ization from the melt, is uniquely u`se:Eul as a component in molding resins, alone or combined wi~h reinforcement, in comparison with other thermoplastics, offer a high degree of surface hardness and abrasion resistance, high gloss, and lower surface friction~
:
,,- .~ .~
, ~''' " ' ', ~6~S13~
- 2 - 8CV-38~6 Stable polyblends of poly(l,4-butylene terephthalate) and poly(ethylene terephthalate) can be molded into useful unreinforced and reinforced articles. See U.S. Patent 3~953~394l issued April 27, 1976 to Fox and Wambach.
Block copolyesters derived ~rom terminally-relative pre-formed blocks of poly(1,4-butylene terephthalate) and from terminally-reactive pre-formed blocks of an aromatic/aliphatic or aliphatic polyester have been disclosed in the literature. Such block copolyesters are useful per se as molding resins and also in intimate combination with poly(l,4-butylene terephthalate) and/or poly(ethylene terephthalate) resins.
~5 It has been proposed to increase th~ impact strength of polyesters by adding various modifiers.
For example, in U.S~ Patent 4,044,073, issued August 23, 1977 to Baron et al, disclose that a useful impact modifier for such polyesters is an aromatic polycarbonate. Brinkmann et al in U.S. Patent
With the development of molecular weight control, the use of nucleating agents and two-step-molding cycles, polytethylene terephthalate) has become an important constituent of injection moldable compositions.
Poly(1,4-butylene terephthalate), because of its very rapid crystal].ization from the melt, is uniquely u`se:Eul as a component in molding resins, alone or combined wi~h reinforcement, in comparison with other thermoplastics, offer a high degree of surface hardness and abrasion resistance, high gloss, and lower surface friction~
:
,,- .~ .~
, ~''' " ' ', ~6~S13~
- 2 - 8CV-38~6 Stable polyblends of poly(l,4-butylene terephthalate) and poly(ethylene terephthalate) can be molded into useful unreinforced and reinforced articles. See U.S. Patent 3~953~394l issued April 27, 1976 to Fox and Wambach.
Block copolyesters derived ~rom terminally-relative pre-formed blocks of poly(1,4-butylene terephthalate) and from terminally-reactive pre-formed blocks of an aromatic/aliphatic or aliphatic polyester have been disclosed in the literature. Such block copolyesters are useful per se as molding resins and also in intimate combination with poly(l,4-butylene terephthalate) and/or poly(ethylene terephthalate) resins.
~5 It has been proposed to increase th~ impact strength of polyesters by adding various modifiers.
For example, in U.S~ Patent 4,044,073, issued August 23, 1977 to Baron et al, disclose that a useful impact modifier for such polyesters is an aromatic polycarbonate. Brinkmann et al in U.S. Patent
3,591,659, issued July 6, 1971, disclose that a useful family of modifiers comprises polyalkylacrylates, methacrylates and/or ethacrylates. Schlichting et al, in U.S. Patent 4,022,748, issued May 10, 1977, disclose that a rubber-elastic graft copolymer having a glass transition temperature below -20C. is a useful modifier.
U.S. Patent 3,864,428, issued February 4, 1975 to Nakamura et al, disclose that compositions comprising a major proportion of an aromatic polyester, a minor proportion of an aromatic polycarbonate, and from 1 to 30~ by weight of a simple grafted methyl methacrylate-butadiene-styrene copolymer possess improved impact strength and chemical resistance over the ,~
., .. . . .
::-- , ~.~ :
:: , :. : .
~2~X5~
polycarbonate resin alone.
More recently, it has been discovered that the addition of certain grafted core-shell copolymer resins to polyester resin compositions provides articles molded therefrom with superior impact resistance over a broad range of temperatures. One type of core-shell ; graft copolymer modifier having a butadiene-based core and methacrylate shell is described in U.S. Patent No. 4,180,494, issued December 25, 1979 to Froumuth et al. I'hese core-shell copolymers comprise a rubbery first stage polymerized fxom a monomer system comprising 50 percent by weight of butadiene, alone or in combination with a vinyl monomer, e.g. styrene, and a rigid thermo-plastic final stage polymerized from methyl methacrylate and a crosslinking monomer. As is described in the above-identified patent, when a modifier cor.lbination comprlsing an aromatic polycarbonate resin and this butadiene-based core-shell copolymer resin is added to a polyester composition comprising a poly(l,4-butylene terephthalate) resin, shaped articles molded therefrom possess good impact strength. The patent also discloses that, while methyl methacrylate-butadiene-styrene copolymers not of the core-shell type, also provide good impact strength at room temperatures of about 23C, only the compositions made with the core-shell copolymers retain more than 70~ of their impact strength at -40C, making them uniquely suitable for molding such articles as automobile bumpers, ski bindings and the likel where low-temperature impact resistance is important.
Other useful core-shell copolymer resins are those having a rubbery acrylate core and a hard methyacrylate shell such as are described in ~arnham et al, U.S. Patent NoO 4,096,202, issued June 20, 1978. As disclosed therein, the acrylate-based core shell copolymer resins are comprised of a ~.~
~6~
- ~ - 8CU 3846 rubbery first phase polymerized from a monomer system comprising a Cl-C6 alkyl acrylate and minor amounts oE
a crosslinking monomer and a graft-linking monomer, respectively, and a rigid thermoplastic final phase polymerized from a monomer system comprising at least 50% by weight of a Cl-C6 alkyl methacrylate. These core-shell copolymer resins provide enhanced impact strenyth to saturated polyester compositions.
In U.S. Patent No. 4,260,693, issued April 7 l9gl to Liu, assigned to the same assignee as -the present invention, it is disclosed that aromatic poly-carbonates may be impact modified with an acrylate-based core-shell copolymer resin and an olefin~acrylate copolymer resin.
In U.S. Patent ~,257,937, issued March 24, 1981 to Cohen et al and in U.S. Patent ~,264,~87, issued ~pril 28, 1981 to Fromuth e-t al, impact modified thermoplastic compositions are disclosed which comprise a poly(alkylene terephthalate) resin, an aromatic poly-carbonate resin and an acrylate-based core-shell copolymer resin.
Impact modified thermoplastic compositions are known comprising a polyester resin, an aromatic poly-carbonate resin or mixtures thereo~ and a precompounded modified composition comprising a butadiene-based core-shell copolymer resin and an antioxidant/stabilizer package comprising a hindered phenolic antioxidant, an aromatic amine, a thioester and a trivalent phosphorus compound. The precompounded modifier may optionally 3Q contain a polyolefin resin added to facilitate the preblending of the core-shell copolymer with the combination of stabilizers. The precompounded impact modifier and stabilizer package are more easily dispersable in the other polymeric components and effectively reduce the hazards associated with the handling and processing of rubber dusts. In addition, "
, . ~
- , :~ .
'-:
' .
2~
~CU-3~46 : -5- -precompounding of the temperature sensitive butadiene-based core-shell resin with stabilizer dec~eases the degradation o~ the impact modifier which improves the impact resistance of the overall composition after processing.
Although many of the above-mentioned patents provide polyester or polycarbonate compositions possessing good impact strength at room temperature and some at lower temperatures, other polyester compositions 1~ exhibiting improved impact strength at both lower and room -temperatures which also possess improved storage stability, improved melt :flow, improved tensile elongation and better part appearance are still needed : and desired.
~ ~ 7 ~ ' .
~ ~ 8CU-3846 _ MMARY OF THE INVENTION
Unexpectedly, in view o~ the oregoing, it has been discovered that a thermoplastic oomposition comprising a linear or branched saturated polyester homopolymer or copolymer resin and an aromatic poly-carbonate resin may be provided wi~h retained impact stren~th, with reduced mel, viscosity and improved melt flow, improved tensile elongation, improved storage s~ability and better part appearance by incorporating thereln, in certain proportions, a modifier combination comprising a mul~iphase co.~osite interpolymer having a ruvDery ~cr~la~e core a..~ a ~ a ~ner~opias~ic sneil together with an olefin polymer or copolymer.
Although it is known that butadiene ox acrylic rubbers can improve the impact ~trength of polyester resins, most of these additi~es are, in general, finely divided particles prepared by emulsion polymeri-zation which are diffult to handle. These polymer dusts are extremely flammable and the potential for dust explosions during the handling of these materials is a significant risk. Moreover, the dispersion of the powders into the polymer matrix during normal processing is generally poor.
Therefore, in acoordance with a preferred embodiment of the preseAt invention, a multiphase composite interpolym~r having an acrylate core and a thermoplastic methacrylate shell is first precompounded with an ole~in homopolymer or copolymer under relatively mild conditio~s of low tempera ure and low shear to form .30 a concentrate. Whe~ the resulting concentrate i5 there-after intimately admixed with the polyester resin compo-sition ~t the relatively high Droce-esing temperatures normally required to melt the polyester~ the pre-compounded concentrate is easily melt blended into the 3~
6~ 8CU-3846 7 _ the polyester resulting in reduced melt viscosity and improved mel~ flow and a more complete and uniform disp2rsion of the impact modiiers throughout th2 polymer matrix is obtained. This results in improved te~sile Dlongation and improved part appearance.
The acrylate based multiphase composite interpolymer is relatively less temperature sensitive and therefore does not su.fer the same tempera.ure àegraaation obser~ed with earlier butadiene-based materials which rDquire the further addition of expensive antioxidants and stabilizers. Moreover, the precompounded concentrate is easier to handle and eliminates or ~ubst~tially reduces the danger of chemical dust explosions and worker exposure to chemical dust.
Moreover, the addition of the olefinic res.in permits a reduction in the levels of the multiphase core-shell interpolymer resin without sacrificing other beneficial propexties which provides a su~stantial reduction in the cost for the compositions of this invention.
Other objects and advantages of the present invention will become apparent from the following detailed description and illustrative working examples.
DETAILED DESCRIPTION OF THE I~ENTION
In accordance with the subject invention new and improved thermoplastic molding compositions are provided in the form of resin mixtures comprising:
la) a polyester comprising:
(i1 a poly5alkylene terephthalate3 3~ resin;
(ii) a blend of a poly(l,4-butylene terephthalate) resin and a poly ~ethylene terephthalate) resin;
..
~ 5~ 8Cu-3846 O
(iii~ a bloc~ copol~estE~r of poly~l,4-butylene terephthalate) and an aromatic/aliphatic or aliphatic polyester;
(iv~ a blend of (iii) and a poly (ethylene terephthalate) resin; or (v) a blend ~f tiii~ a poly(l,4-butylene terephthalate~ resin;
(b~ an aromatic polycarbonate resin; an,~
(c~ an effective amount of a modifier combination complising:
( ) a multiphase composite core-sh~
interpolymer comprising a firs~
elastomeric core stage of a Cl-C6 alkyl acrylate together with a cross-linking monomer and a gr~ft-linking monomer and a hard fi~l stage comprising, completely o~
predominantly, Cl-C6 alkyl me~-acrylate; and (ii) an olefinic resin selected r~ Cl-Clo olefin homopolymers, ble~d of two or more of said olefLn ~om~-polymers and a copolymer of an olefin and at lea~t one monomeric compound selected from a Cl-C6 al~yl acrylate, a Cl C6 methac~ylate, acrylic acid, methacrylic aci~ or a mixtuxe of any o the forego~ng.
30 : Th~ thermoplastic ~ompositions of the present i~vention may also includ~ reinforcin~ agents, su¢~ as :~ glass fibers, mineral fillers,such as olays, m~ca and/or ~ talc, as well a~, flame retardan~ agents.
: 35 ,. .
."
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2~
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In a preferred embodiment, the m~difier com-bination is added as a precompounded composition, or concentrate, of the acrylate-based multiphase composite interpolymer and the polyolein resin, resin blend, or ole.in copolymer resin. This precompounding permits the use of smaller amounts of core-shell interpolymer ~es~n, and ?rovides be!ter processability and moldability, better Dart appearance and improved handling safety, to be more fully described hereinafter.
~ore particularly, the polyesters suitable for use as component ta) herein may be any of the linear or branched saturated ~olvesters known to those skilled in this art. Generally, the polyesters will comprise linear saturated polyester5 derived from Cl~C10 alkylene glycols such as ethylene glycol, propylene glycol, 1,4-butanediol etc., including cycloaliphatic glycols, such as 1,4-cyclohexanedimethanol, and mixtures of any of ~hese glycol~ wi~h one or more aroma~ic dicar~oxylic acids~ Pr~ferably, the polyesters will comprise poly~C1-C6 alkylene terephthalates~ prepared by known techniques, such as the transesterification of esters of terephthalic acid alone or mixtures of esters of terephthalic acid and isophthalic acid, with the glycol or mixture of glycols and subsequent polymerization, by heating the glycols with the free acids or with halide derivatives thereof, a~d similar processes.
These methods axe described i~ U~S. 2,465,31g and 3,047,539 incorporated herei~ by reference and else-where. In addition blends of one or morP of these polyesters or copolyesters may be employed~ A suitable poly(1,~. butylene terephthalate) resin is commercially available from General Electric Compan~ under the trade designationJ VALO ~ 315, and poly(ethylene terephthalate) resins are al~o extremely well known and are abundantly available commercially.
., - 10 - ~CU 3846 The block copolyester resins for use as component (a)(iii~ above, can be prepared by the transesterification of (a) straight or branched chain poly(l,4-butylene terephthalate) and (b) a copolyester of a linear aliphatic dicarboxylic acid and, optionally, an aromatic dibasic acid with one or more straight or branched chain dihydric aliphatic glycols. For example, a poly(l,4-butylene terephthalate~ can be mixed with a polyester of adipic acid and ethylene glycol, and heated at 235C to melt the ingredients, then heated further under a vacuum until the formation of the copolyester is complete. As the second component, there can be substituted poly(neopentyl adipate), poly(1,6-hexylene azelate-co-isophthalate~, poly(l,6-hex~lene adipate-co-isophthalate) and the like.
Illustratively, the high molecular weight polyesters will have an intrinsic viscosity of at least about 0.2 deciliters/gram and, preferably, at least about 0.4 deciliters/gram as measured in a 60/40 phenol/tetrachloroethane mixture at 30C, for poly(ethylene terephthalate) and at least 0.6 and more preferably 0.8 deciliters/gram, same basis, for poly(.l,4-butylene terephthalate).
Most preferably, for the former, the intrinsic viscosity will be in the range of 0.5 to 1.0 dl~/g.
and from 0.9 to 1.2 for the latter.
Especially useful when high melt strength is important are branched high melt viscosity poly(l,4-butylene terephthalate) resins, which include asmall amount, e.g., up to 5 mole percent based on the .,. ~ .
~, :' :
5 ~ .
~erephthalate units, of a branching component con.ain-ing a~ leas~ three ester forming groups. T~e branching component can be one which provides branching in the acid unit portion of the polyester, or in th2 glycol unit portion, or it can be a hydrid~ Illustrative of such branching components are tri- or t:etracarboxylic ecids, such as trimesic acia, ~yromeilitic aci2, an~.
lower al~yl es~ers ~hereof/ a..c the like, o- p-e~e_~-ly, polyols, and especially prefer2bly, tetrols, such as pentaerythritol, triols, such as trimethylolpropane;
or dihvdroxy carboxylic acids and hydroxydicarboxylic acids and derivati.ves, such as tartaric acids, and the like.
The branched poly(l,4-butylene terephthalate) resins and their preparation are descrlbed in Borman, U.S~ 3,953,404, ~sued April 27, 1976.
Th~ aromatic polycarbonate resins for use herein as component ~b) may be prepared by reacting a dihydric phenol with a carbonate precursor, such as phosgene, a haloformate or a carbonate ester. Generally speaking, such carbonate polymers may be typified as possessing recurring structural units of the formula:
~ O~
I ~ O - A - O - ~ ~
2S wherein A i~ a divalent aromatic radical of the dihydric phenol employed in the polymer producing r~action.
Pre~erably, the carbonate polymers used to provide ~he resinous mixtures of the invention have an intrinsic viscosity (as measured i~ methylene chloride at 25C.) ra~ging from about 0.30 to about 1.00 dl./~. The dihydric phenol which may be employed to provide such aromatic carbonate polymers are mononuclear or poly-nuclear aromatic compounds, containing as func~ional groups two hydroxy radicals, each of which is attached directly ~o a carbon atom of an aromatic nucleus.
r~ , 12_ Typical dihydric phenols are:
2,2-~is~(4-hydroxyphenyl~propane;
hydroquinone~
resorcinol;
2,2-bis-(4-hydroxyphenyl)pe~tane;
2,4'-~dihydroxydiphenyl)methane;
bis-~2-hydroxyphenyl)methane;
bis ~4-hvdroxyphenyl)methane;
bis-~4-hydroxy-~-nitrophenyl3methane;
1,1 bis~4-hydroxyphenyl~ethane;
~,3-bisl4 hydroxyphenyl)2entane;
2,2-dihydroxydiph~nyl;
2,6-dihydroxynaphthalene;
bis-~4-hydroxydiphenyl~sulfone;
bis-(3~5-diethyl-~-hydroxyphenyl)sul~one;
2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)propane;
2,4'-dihydroxydiphenyl sulfone;
~ 5'-chloro-2,4'-dihydroxydiphenyl sulfon~;
; 20 bis-(4-hydroxyphenyl)diphenyl sulfone;
U.S. Patent 3,864,428, issued February 4, 1975 to Nakamura et al, disclose that compositions comprising a major proportion of an aromatic polyester, a minor proportion of an aromatic polycarbonate, and from 1 to 30~ by weight of a simple grafted methyl methacrylate-butadiene-styrene copolymer possess improved impact strength and chemical resistance over the ,~
., .. . . .
::-- , ~.~ :
:: , :. : .
~2~X5~
polycarbonate resin alone.
More recently, it has been discovered that the addition of certain grafted core-shell copolymer resins to polyester resin compositions provides articles molded therefrom with superior impact resistance over a broad range of temperatures. One type of core-shell ; graft copolymer modifier having a butadiene-based core and methacrylate shell is described in U.S. Patent No. 4,180,494, issued December 25, 1979 to Froumuth et al. I'hese core-shell copolymers comprise a rubbery first stage polymerized fxom a monomer system comprising 50 percent by weight of butadiene, alone or in combination with a vinyl monomer, e.g. styrene, and a rigid thermo-plastic final stage polymerized from methyl methacrylate and a crosslinking monomer. As is described in the above-identified patent, when a modifier cor.lbination comprlsing an aromatic polycarbonate resin and this butadiene-based core-shell copolymer resin is added to a polyester composition comprising a poly(l,4-butylene terephthalate) resin, shaped articles molded therefrom possess good impact strength. The patent also discloses that, while methyl methacrylate-butadiene-styrene copolymers not of the core-shell type, also provide good impact strength at room temperatures of about 23C, only the compositions made with the core-shell copolymers retain more than 70~ of their impact strength at -40C, making them uniquely suitable for molding such articles as automobile bumpers, ski bindings and the likel where low-temperature impact resistance is important.
Other useful core-shell copolymer resins are those having a rubbery acrylate core and a hard methyacrylate shell such as are described in ~arnham et al, U.S. Patent NoO 4,096,202, issued June 20, 1978. As disclosed therein, the acrylate-based core shell copolymer resins are comprised of a ~.~
~6~
- ~ - 8CU 3846 rubbery first phase polymerized from a monomer system comprising a Cl-C6 alkyl acrylate and minor amounts oE
a crosslinking monomer and a graft-linking monomer, respectively, and a rigid thermoplastic final phase polymerized from a monomer system comprising at least 50% by weight of a Cl-C6 alkyl methacrylate. These core-shell copolymer resins provide enhanced impact strenyth to saturated polyester compositions.
In U.S. Patent No. 4,260,693, issued April 7 l9gl to Liu, assigned to the same assignee as -the present invention, it is disclosed that aromatic poly-carbonates may be impact modified with an acrylate-based core-shell copolymer resin and an olefin~acrylate copolymer resin.
In U.S. Patent ~,257,937, issued March 24, 1981 to Cohen et al and in U.S. Patent ~,264,~87, issued ~pril 28, 1981 to Fromuth e-t al, impact modified thermoplastic compositions are disclosed which comprise a poly(alkylene terephthalate) resin, an aromatic poly-carbonate resin and an acrylate-based core-shell copolymer resin.
Impact modified thermoplastic compositions are known comprising a polyester resin, an aromatic poly-carbonate resin or mixtures thereo~ and a precompounded modified composition comprising a butadiene-based core-shell copolymer resin and an antioxidant/stabilizer package comprising a hindered phenolic antioxidant, an aromatic amine, a thioester and a trivalent phosphorus compound. The precompounded modifier may optionally 3Q contain a polyolefin resin added to facilitate the preblending of the core-shell copolymer with the combination of stabilizers. The precompounded impact modifier and stabilizer package are more easily dispersable in the other polymeric components and effectively reduce the hazards associated with the handling and processing of rubber dusts. In addition, "
, . ~
- , :~ .
'-:
' .
2~
~CU-3~46 : -5- -precompounding of the temperature sensitive butadiene-based core-shell resin with stabilizer dec~eases the degradation o~ the impact modifier which improves the impact resistance of the overall composition after processing.
Although many of the above-mentioned patents provide polyester or polycarbonate compositions possessing good impact strength at room temperature and some at lower temperatures, other polyester compositions 1~ exhibiting improved impact strength at both lower and room -temperatures which also possess improved storage stability, improved melt :flow, improved tensile elongation and better part appearance are still needed : and desired.
~ ~ 7 ~ ' .
~ ~ 8CU-3846 _ MMARY OF THE INVENTION
Unexpectedly, in view o~ the oregoing, it has been discovered that a thermoplastic oomposition comprising a linear or branched saturated polyester homopolymer or copolymer resin and an aromatic poly-carbonate resin may be provided wi~h retained impact stren~th, with reduced mel, viscosity and improved melt flow, improved tensile elongation, improved storage s~ability and better part appearance by incorporating thereln, in certain proportions, a modifier combination comprising a mul~iphase co.~osite interpolymer having a ruvDery ~cr~la~e core a..~ a ~ a ~ner~opias~ic sneil together with an olefin polymer or copolymer.
Although it is known that butadiene ox acrylic rubbers can improve the impact ~trength of polyester resins, most of these additi~es are, in general, finely divided particles prepared by emulsion polymeri-zation which are diffult to handle. These polymer dusts are extremely flammable and the potential for dust explosions during the handling of these materials is a significant risk. Moreover, the dispersion of the powders into the polymer matrix during normal processing is generally poor.
Therefore, in acoordance with a preferred embodiment of the preseAt invention, a multiphase composite interpolym~r having an acrylate core and a thermoplastic methacrylate shell is first precompounded with an ole~in homopolymer or copolymer under relatively mild conditio~s of low tempera ure and low shear to form .30 a concentrate. Whe~ the resulting concentrate i5 there-after intimately admixed with the polyester resin compo-sition ~t the relatively high Droce-esing temperatures normally required to melt the polyester~ the pre-compounded concentrate is easily melt blended into the 3~
6~ 8CU-3846 7 _ the polyester resulting in reduced melt viscosity and improved mel~ flow and a more complete and uniform disp2rsion of the impact modiiers throughout th2 polymer matrix is obtained. This results in improved te~sile Dlongation and improved part appearance.
The acrylate based multiphase composite interpolymer is relatively less temperature sensitive and therefore does not su.fer the same tempera.ure àegraaation obser~ed with earlier butadiene-based materials which rDquire the further addition of expensive antioxidants and stabilizers. Moreover, the precompounded concentrate is easier to handle and eliminates or ~ubst~tially reduces the danger of chemical dust explosions and worker exposure to chemical dust.
Moreover, the addition of the olefinic res.in permits a reduction in the levels of the multiphase core-shell interpolymer resin without sacrificing other beneficial propexties which provides a su~stantial reduction in the cost for the compositions of this invention.
Other objects and advantages of the present invention will become apparent from the following detailed description and illustrative working examples.
DETAILED DESCRIPTION OF THE I~ENTION
In accordance with the subject invention new and improved thermoplastic molding compositions are provided in the form of resin mixtures comprising:
la) a polyester comprising:
(i1 a poly5alkylene terephthalate3 3~ resin;
(ii) a blend of a poly(l,4-butylene terephthalate) resin and a poly ~ethylene terephthalate) resin;
..
~ 5~ 8Cu-3846 O
(iii~ a bloc~ copol~estE~r of poly~l,4-butylene terephthalate) and an aromatic/aliphatic or aliphatic polyester;
(iv~ a blend of (iii) and a poly (ethylene terephthalate) resin; or (v) a blend ~f tiii~ a poly(l,4-butylene terephthalate~ resin;
(b~ an aromatic polycarbonate resin; an,~
(c~ an effective amount of a modifier combination complising:
( ) a multiphase composite core-sh~
interpolymer comprising a firs~
elastomeric core stage of a Cl-C6 alkyl acrylate together with a cross-linking monomer and a gr~ft-linking monomer and a hard fi~l stage comprising, completely o~
predominantly, Cl-C6 alkyl me~-acrylate; and (ii) an olefinic resin selected r~ Cl-Clo olefin homopolymers, ble~d of two or more of said olefLn ~om~-polymers and a copolymer of an olefin and at lea~t one monomeric compound selected from a Cl-C6 al~yl acrylate, a Cl C6 methac~ylate, acrylic acid, methacrylic aci~ or a mixtuxe of any o the forego~ng.
30 : Th~ thermoplastic ~ompositions of the present i~vention may also includ~ reinforcin~ agents, su¢~ as :~ glass fibers, mineral fillers,such as olays, m~ca and/or ~ talc, as well a~, flame retardan~ agents.
: 35 ,. .
."
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2~
_ g O
In a preferred embodiment, the m~difier com-bination is added as a precompounded composition, or concentrate, of the acrylate-based multiphase composite interpolymer and the polyolein resin, resin blend, or ole.in copolymer resin. This precompounding permits the use of smaller amounts of core-shell interpolymer ~es~n, and ?rovides be!ter processability and moldability, better Dart appearance and improved handling safety, to be more fully described hereinafter.
~ore particularly, the polyesters suitable for use as component ta) herein may be any of the linear or branched saturated ~olvesters known to those skilled in this art. Generally, the polyesters will comprise linear saturated polyester5 derived from Cl~C10 alkylene glycols such as ethylene glycol, propylene glycol, 1,4-butanediol etc., including cycloaliphatic glycols, such as 1,4-cyclohexanedimethanol, and mixtures of any of ~hese glycol~ wi~h one or more aroma~ic dicar~oxylic acids~ Pr~ferably, the polyesters will comprise poly~C1-C6 alkylene terephthalates~ prepared by known techniques, such as the transesterification of esters of terephthalic acid alone or mixtures of esters of terephthalic acid and isophthalic acid, with the glycol or mixture of glycols and subsequent polymerization, by heating the glycols with the free acids or with halide derivatives thereof, a~d similar processes.
These methods axe described i~ U~S. 2,465,31g and 3,047,539 incorporated herei~ by reference and else-where. In addition blends of one or morP of these polyesters or copolyesters may be employed~ A suitable poly(1,~. butylene terephthalate) resin is commercially available from General Electric Compan~ under the trade designationJ VALO ~ 315, and poly(ethylene terephthalate) resins are al~o extremely well known and are abundantly available commercially.
., - 10 - ~CU 3846 The block copolyester resins for use as component (a)(iii~ above, can be prepared by the transesterification of (a) straight or branched chain poly(l,4-butylene terephthalate) and (b) a copolyester of a linear aliphatic dicarboxylic acid and, optionally, an aromatic dibasic acid with one or more straight or branched chain dihydric aliphatic glycols. For example, a poly(l,4-butylene terephthalate~ can be mixed with a polyester of adipic acid and ethylene glycol, and heated at 235C to melt the ingredients, then heated further under a vacuum until the formation of the copolyester is complete. As the second component, there can be substituted poly(neopentyl adipate), poly(1,6-hexylene azelate-co-isophthalate~, poly(l,6-hex~lene adipate-co-isophthalate) and the like.
Illustratively, the high molecular weight polyesters will have an intrinsic viscosity of at least about 0.2 deciliters/gram and, preferably, at least about 0.4 deciliters/gram as measured in a 60/40 phenol/tetrachloroethane mixture at 30C, for poly(ethylene terephthalate) and at least 0.6 and more preferably 0.8 deciliters/gram, same basis, for poly(.l,4-butylene terephthalate).
Most preferably, for the former, the intrinsic viscosity will be in the range of 0.5 to 1.0 dl~/g.
and from 0.9 to 1.2 for the latter.
Especially useful when high melt strength is important are branched high melt viscosity poly(l,4-butylene terephthalate) resins, which include asmall amount, e.g., up to 5 mole percent based on the .,. ~ .
~, :' :
5 ~ .
~erephthalate units, of a branching component con.ain-ing a~ leas~ three ester forming groups. T~e branching component can be one which provides branching in the acid unit portion of the polyester, or in th2 glycol unit portion, or it can be a hydrid~ Illustrative of such branching components are tri- or t:etracarboxylic ecids, such as trimesic acia, ~yromeilitic aci2, an~.
lower al~yl es~ers ~hereof/ a..c the like, o- p-e~e_~-ly, polyols, and especially prefer2bly, tetrols, such as pentaerythritol, triols, such as trimethylolpropane;
or dihvdroxy carboxylic acids and hydroxydicarboxylic acids and derivati.ves, such as tartaric acids, and the like.
The branched poly(l,4-butylene terephthalate) resins and their preparation are descrlbed in Borman, U.S~ 3,953,404, ~sued April 27, 1976.
Th~ aromatic polycarbonate resins for use herein as component ~b) may be prepared by reacting a dihydric phenol with a carbonate precursor, such as phosgene, a haloformate or a carbonate ester. Generally speaking, such carbonate polymers may be typified as possessing recurring structural units of the formula:
~ O~
I ~ O - A - O - ~ ~
2S wherein A i~ a divalent aromatic radical of the dihydric phenol employed in the polymer producing r~action.
Pre~erably, the carbonate polymers used to provide ~he resinous mixtures of the invention have an intrinsic viscosity (as measured i~ methylene chloride at 25C.) ra~ging from about 0.30 to about 1.00 dl./~. The dihydric phenol which may be employed to provide such aromatic carbonate polymers are mononuclear or poly-nuclear aromatic compounds, containing as func~ional groups two hydroxy radicals, each of which is attached directly ~o a carbon atom of an aromatic nucleus.
r~ , 12_ Typical dihydric phenols are:
2,2-~is~(4-hydroxyphenyl~propane;
hydroquinone~
resorcinol;
2,2-bis-(4-hydroxyphenyl)pe~tane;
2,4'-~dihydroxydiphenyl)methane;
bis-~2-hydroxyphenyl)methane;
bis ~4-hvdroxyphenyl)methane;
bis-~4-hydroxy-~-nitrophenyl3methane;
1,1 bis~4-hydroxyphenyl~ethane;
~,3-bisl4 hydroxyphenyl)2entane;
2,2-dihydroxydiph~nyl;
2,6-dihydroxynaphthalene;
bis-~4-hydroxydiphenyl~sulfone;
bis-(3~5-diethyl-~-hydroxyphenyl)sul~one;
2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)propane;
2,4'-dihydroxydiphenyl sulfone;
~ 5'-chloro-2,4'-dihydroxydiphenyl sulfon~;
; 20 bis-(4-hydroxyphenyl)diphenyl sulfone;
4,4'-aihydroxydiphenyl ether;
4,4'-dihydroxy-3,3'-dichlorodiphenyl ether;
4,4' dihydroxy-2,5-dihydroxydiphenyl ether7 and the like.
Other ~ihydric phe~ols which are also suitable for use in the preparation of the abovc polycarbonates are disclosed in U.S~ 2,999,835; 3,038,365; 3,334,154;
an~ 4,131,575.
The~ aromatic polycarbonates can ~e manu-factured by known processes, such as, for example and as mentioned above, by reacting a dihydric phenol with a carbonate precursor, such as phosgene, in a~cordance wi~h methods set forth in the a~ove-cited literature . and in U.S. 4,123,436, or by ~ransesterification processes such as are disclosed in U.S. 3,153,008, as 13_ well as other processes known to those skilled in the art.
It is possible to employ two or more dif~erent dihydric phenols or a copolymer of a d:ihydric phenol with a glycol or with a hydroxy- or ac:id-~erminate~
polyester or with a dibasic acid in the event a car~onate cooolymer or in~erpolymer rather than a homo-pol~mer is cesired for use in ~he pre~ara~ion of tne polycarbonate mixtures of the invention. Branched polycarbonates are also useful, such as are descri~ed in U . 5 . 4 ~ 001,184. Also there can be utilized blen~s o llnear polycarbonate and a branched ~olvc2rbonat.e.
Moreover, ble~ds of any of the above materials may ~e employed in the practice o~ thi~ inventian to provi~e 15 the aromatic polycarbonate. In any event, the preferred aromatic carbGnate polymer ~or use as component tb~
herein is a homopolymer derived from 2,2 bis(4-hydroxy-phenyl) propane (bisphenol-A), coIranercially available under th~ trade designation LEXAN~ from General Electric 20 Company.
In the modifier combination (c), the mul~i-phase composite core-shell interpolymer componen~ ~c) (i~ is a core-shell interpolymer comprising about 2 to 95 percent by weight of a first elastomeric core phase and about 75 to 5 percent by weight of a fin~l rigid therm~plastic shell phase. One or more intermed-iate phases re optional, for example, a middle stage polymerized from about 75 to 100 percen~ by wQight styrene.
The fir-t stage or core of multiphase composite interpolymer component ~c)(i) is polymerized from ~bout 7S to 99.8 ~eight percent Cl to C6 alkyl acrylate re~ulting in an acryli~ rubber core having a T~ be ow about 10C. and crosslinked with 0.1 to S weight percen~
crosslinking monom~r and further containin~ 0.1 to S
,, : :
' ~ ... .
.: .
4,4'-dihydroxy-3,3'-dichlorodiphenyl ether;
4,4' dihydroxy-2,5-dihydroxydiphenyl ether7 and the like.
Other ~ihydric phe~ols which are also suitable for use in the preparation of the abovc polycarbonates are disclosed in U.S~ 2,999,835; 3,038,365; 3,334,154;
an~ 4,131,575.
The~ aromatic polycarbonates can ~e manu-factured by known processes, such as, for example and as mentioned above, by reacting a dihydric phenol with a carbonate precursor, such as phosgene, in a~cordance wi~h methods set forth in the a~ove-cited literature . and in U.S. 4,123,436, or by ~ransesterification processes such as are disclosed in U.S. 3,153,008, as 13_ well as other processes known to those skilled in the art.
It is possible to employ two or more dif~erent dihydric phenols or a copolymer of a d:ihydric phenol with a glycol or with a hydroxy- or ac:id-~erminate~
polyester or with a dibasic acid in the event a car~onate cooolymer or in~erpolymer rather than a homo-pol~mer is cesired for use in ~he pre~ara~ion of tne polycarbonate mixtures of the invention. Branched polycarbonates are also useful, such as are descri~ed in U . 5 . 4 ~ 001,184. Also there can be utilized blen~s o llnear polycarbonate and a branched ~olvc2rbonat.e.
Moreover, ble~ds of any of the above materials may ~e employed in the practice o~ thi~ inventian to provi~e 15 the aromatic polycarbonate. In any event, the preferred aromatic carbGnate polymer ~or use as component tb~
herein is a homopolymer derived from 2,2 bis(4-hydroxy-phenyl) propane (bisphenol-A), coIranercially available under th~ trade designation LEXAN~ from General Electric 20 Company.
In the modifier combination (c), the mul~i-phase composite core-shell interpolymer componen~ ~c) (i~ is a core-shell interpolymer comprising about 2 to 95 percent by weight of a first elastomeric core phase and about 75 to 5 percent by weight of a fin~l rigid therm~plastic shell phase. One or more intermed-iate phases re optional, for example, a middle stage polymerized from about 75 to 100 percen~ by wQight styrene.
The fir-t stage or core of multiphase composite interpolymer component ~c)(i) is polymerized from ~bout 7S to 99.8 ~eight percent Cl to C6 alkyl acrylate re~ulting in an acryli~ rubber core having a T~ be ow about 10C. and crosslinked with 0.1 to S weight percen~
crosslinking monom~r and further containin~ 0.1 to S
,, : :
' ~ ... .
.: .
5 ~ 8CU-38~6 ~ O
percent by weight gr~ftlinking monomer. The preferxed alkyl ac~ylate i5 butyl acrylate. The crosslinking monomeriSa polyethylenically unsaturated m~nomer having a plurality of addition polymerizable .reac~ive groups all of which polymerize a~ substantial.ly the same rate of reaction. Suitable crosslinking monomers include poly acrylic a~d poly ~ethacrylic es~ers o~ polyols sueh as butylene diacrylate and dimethacrylate, ~ri-methylol propane trimethacrylate, and the like, di-and ~rivinyl benzene, vinyl acrylate and methacrylate,and the like. The preferred crosslinking monomer is butylene diacrylate.
The graftlinking monomer is a polyethylenically unsaturated monomer h~ving a plurality of addition polyme~izable reactive groups, at least one of which polymerizes at a substantially different r~te of poly merization from at least one other of saia reactive groups. The function o~ the gxaftlinking monomer is to provide a xesidual level of unsaturation in the elastomeric phase, particularly in the latter staaes of polymerization, and consequently, at or ~ear the suxface of the elastomer particles. When the riyid thermoplastic shell phase is subsequently polymerized at the surface o~ the elastomer, the resi~lal unsaturated, addi~io~;polymerizable reactive group contributed by the graftlinking monomex participates in the ~ubsequent xeaction so that at lea~t a portio~ of the rigid shell phase is chemically attached to th~ surfaçe of the elastom~r~. .
Among the effective graftlinki~g monomers are allyl group-co~taining monomers of allyl esters of ethylenically unsaturated acids, such as allyl acrylate, allyl methacrylate, di llyl maleate J diallyl fumarate, diallyl itaconate, allyl acid maleate, allyl acid fumarate, and allyl aci~ itaconate. Somewhat less .
~2~4 8CU-3846 15 _ O
preferred are the diallyl es~ers of po~.y~a~boxylic acids which do not contain polymerizable unsa~ration. The preerred graftlinking monomers are al~l methacrylat~
and diallyl maleate. A most preferred interpolymer has only two s~ages, the first stage comprising about 60 to 95 percent ~y weight of the interpolym~ and being poly-~erized from a monomer system com~rising 95 to 99 . g ?ercent bv weight butyl acrylate, 0.1 to 2.5 percent by weight butylene diacrylate as crosslIn~ing agent, 0.1 to 2.5 percent ~y weight allyl met~acrylate or diallyl maleate as graCtlinking acent w~th a final stage polymerized from about 60 to 100 percent by weight methacrylate. A pre~erred two stage ir~er?olymer of this type is commercially available unde~ the tradename, ACRYLOID KM 330, from Rohm & Haas Chemi~al Company.
The final or shell stage mon~ner system can be compxised of Cl to Cl6 methacrylate, styrenet acrylo-nitrile, alkyl acrylates, allyl methacrylate, diallyl methacrylate, and the like, as long as ~he overall Tg system is at least 20C. Preerably t~e final stage monomeric system is at least 50 weight ~ercent Cl to C~
alkyl methacrylate. It is further pre'~rred that the final stage polymer be free of units w~,ich tend to degrade poly(alkylene terephthalates), for exam~le~acld, hydroxy~, amino, and amide groups.
The multiphase composite interpolymers are - prepared se~uentially by emulsion polymeriza~ion tech-nique~ whexein each successive outer s~age coats the previous stage polymer. ~y way of illustr~tion, the monomeric Cl-C6 acrylate, the cross-linking monomer and the graft-linking monomer are copolymerized in water i~
the presence of a free-radical generating catalyst and a pol~merization regulator which ser~es as a chain transfer agent, at a temperature on the order of f~om 15Co to 80C~ Th~ first elastomexic ~26258~ 8cu-3846 _16 _ O
phase is formed iIl situ to pro~i~ a latex o~ the core copol~mer.
Therea~ter, the second rigid thermoplastic phase monomers are added and are emulsion polymerized with the core-copolymer latex to form the interpolymers.
A more detailed descriptio~ of the preparation of the inte-polymers for use h~r~in as component ~c)(i) is ound in U.S. 4,034,013, issued June 28, 1977 and U.S.
4,096,202, issued June 20, 1978.
Component ~c)~ii) comprises an olefin resin selected from olef inic homopolymers and copolymers.
The olefin homopolymers are well known and commercially available and may be selected from polyethylene, poly-propylene, polyisobutylene and the like and also may lS be present-in the form of mixtures of these homopolymers.
The preferred homopolymer for use herein i5 polyethylene.
Especial~y preferred for use an olefinic ~: component (c)(ii) herein is a copolymer o~ an olefin and at least one monomeric compound selected from the group consisting of a Cl-C6 alkyl acrylate, a Cl-C6 alkyl m~thacrylate, acrylic cid, methacrylic acid and a mixture of any of the _oresoing.
: Copolymer com~onent (c3lii) is made from ~n olefin, e.~.p ethylene, propylene, or the liXe, copolymerized with one or more of a comonomer comprising a Cl-C6 alkyl acryla~e, e.g., methyl acrylate, ethyl acrylate, hexyl acrylate and the like; a Cl-C6 alkyl me~hacrylate, e.g., methyl methacrylate~ ethyl meth-acrylate, hexyl methacrylate, a~d the like; acrylic acid; or methacrylic ac~d. ~specially preferred are the well known copolymers of Pthyle~e with ~n alkyl ester of acrylic acid. These are disc}osed in U.S.
2,953,551. Generally, the acrylate or methacrylate portion of the c~polymer can range from about lO to abou~30 weight percent. The olefin portion of the :
.: , ~, ~
:: : ~ :.
5~4~
~CU-3846 _ 17~
copolymer can range from about 70 to about 90 weight percent. The preferred copol~mer for use as component (c~(ii) is a~ ethylene~ethyl acrylate copolymer in which the weight ratio of the ethylene fracti~n to the ethyl acrylate fraction is about 4.5 to 1. Suitable olefin-acrylate copolymers, as defined above, can be prepared by methods well known to those skilled in the art or can be ~b~ained co~mercially. E~or example, Union Carbide's BAKELITE~ DPD-6169 ethylene-ethyl 1~ acrylate copolymer is suitable for use in the present invention.
In accordance with a preferred embodiment of the subject invention, modifier combination ~c) is precompounded to ~orm a concentxate which is thereafter admiY.ed with the polyester and polycaxbonate and other additives~
The precompounded composition is pxepaxed by m~lt blending the core-shell interpolymer and the polyolefin or olefin-copolymer in equipment such as a compounding extru~er, rubber mill, Banbury mixer and the like, followed by dicing or pelletizing of the preblended components.
In certain preferred features of he composi-tions will include fillers, especially reinforcing fillers such.as ~ibrous (filamentous~ glass or mineral fillers, such as clay, mica, talc, and the like, pre-ferably clay. The fillers can be untreated or treated with silane or titanate coupling agents, etc. The filamentou~ glass ~o be employed as reinforcement in such embodiments of the present compositions is well known to those skilled in the art and i5 widely available rom a number of manufacturers. For compositions ul~im~tely to be employed for electrical uses, it is pxeferred to use fibrous glass filaments comprise~ of lime-aluminum borosilicate gl2ss that is relatively soda ~L2~
_ 18_ .~ O
free. This is known as "E" glass. However, other glasses are useful where elec~rical properties are not so i~portant, e~g., the low soda glass known as "C" glass. The filaments are made by standard processes, e.g., hy steam or air blowing, flame blowing and mechanical ~ulling. The preferred filaments for plastic rein~orcement are made by mechanical pullins.
The filament diameters range ~rom about 0.00012 to 0O00075 inch, but this is not critical to the present invention, The length of the glass filaments and whether or not they are bundled into fibers and the fibers bundled in turn to yarns, ropes or rovings, or woven into mats, and the like, are also not critical to the invention. Elowever, in preparing the mo].ding compositions, it is convenient to use the filamentous glass in the form of chopped strands of from about one-eighth to about 2 inches longO In articles mo~ded from the compositions, on the othPr hand, even shorter lengths will be encountered besause, during compounding, considerable fragmentation will occur. This is desir-able, however, because the best properties are exhibite~
by thermoplastic injection molded articles in whic~
the filament lenghts lie between abou~ 0.0005 to 0.250 inch.
The amount of the filler can vary widely depending ~n the formulation and needs of the partic-ular composition, it being essen~ial only that an amount is selected which is at leas~ sufficie~ to provide reinforcemen~. Preferably, however, ~he reinforcing fil1er will comprise from about 1 to about 60~ by weight of filler ~d) and components la), (b~ and ~c~
combined.
, ~2~ CU~38~6 _ 19 _ The modified polyester compositions of the presen~ invention, alone, or in combination with a filler or fillers can be ren~ered flame retardant with an effe tive amoun~ of a conventional flame retardant agen~ (e3. As is well known, flame retardants can be based on elementary red phosphorus, phosphorus compounds, halocen and nitrogen co~ounds alone, or preferably in Curther combination with syneraists, such as an~imo:ny com~ounds. Especially useful are polymeric and oli~o-meric flame retardant agents comprising tetrabromobis-phenol-A carbonate units, see, for examp}e, Wambach, U.S.
3,~33,6~, issued September 3, 1974.
Other ingredients such as dyes, pigments, drip retardants and the like can be added in conventi.onal amounts or their conventionally employed purposes.
Generally, the new and improved compositions of the subject invention will comprise fxom about 40 to about 90 parts by weight polyester component (a); from about 10 to about 60 parts by weight aromatic polycarbon-ate component (b); and from about 1 to about 40 parts byweight of modifier combination (c), based upon ~he total weight of components (a), (b) and (c) com~ined~ More particularly,m3clier combination(c) will preferably com-prise from about 5 to about 30 parts by weight of multi-phas~ composite.interpolymer component (c)~ and fromabout 1 p~rt to about 15 parts by weigh~ of olefinic homopolymer or copolymex component (c)(ii), based upon the total weight of the overall composition.
As explained previously, the modifier combina~
tion, or preferably the modifier concentrate, is .admixed with the other ingredients of the final composi-tionO This can be done in one conve~ient manner by tumbling the concentrate and other components to form a dry hlend, extruding the blend at a temperature 3S between 450 to S50F, cooling the ex~ruda~e, orming it . .
.
L' ~
8CU~3846 _ ~0 O
into pellets and injection moldinq at ~ te~perature of 450 to 550F. (50 to 250F. mold temperature~.
The new and improved modi~ie~ polyester composition~ of the present inventio~ e~hibit decr~ased melt viscosity and improved melt flow ~endering them well suited ~or use in injection mold~-ng a;pplications.
In the preferred embodiment ~herein th~ modifier combination is present as a precompounded co~.?osi~ion, the acrylate/methacrylate core-shell c~polymer powder~
a-e ~etted and pre-~elletized with the ~ol~olefin resin, resin blend or copolyr.er resin which e~ectively reduces o- removes the hazards associated with ~lending or bulk blending these rubber particles with o~her resinous polymeric components. The modi~er co~c~ntrate provides a pre-dispersed impact modifier, which when blended with t:~e po'yester a~d polyca~bonate resins, is more easily and ~ffectively dis~ersed throughout, which provides better part appearance and tensile elongation while the Lmpact strength is retained.
In order that those skilled in the art may better understand how the present inve~tion may be practiced, the following examples are given by way of illustration and not by way o~ limitatlon.
D CRIPTION OF THE PREFERRE~ EMBODIMENTS
In the following examples, æll parts and perce~tages are by weiyht unless otherwis~ noted. The various polyester compositions were ~irst dry blended~
the~ compounded and extruded in a Proaex extrud~ at 500F. and finally molded in a Van Dorm injection moldiny machine at 480F. to form tes~ specimens. The test specimens were molded to form ASTM test bars of 2~" x 1/~" x 1/8" dimensions. Resistance to impact failure of the specimens was determined i~ accordance with the Notched Izod Impact Te~t, ASTM D256 on both notched and unno~ched specimens.
~:6~8~ ~cu-3846 A precompounded concentra~e was p~epared by tumblin~ 100 parts of an acrylate/methzlcrylate core-shell copolymer~ ACRYLOID KM 330, Rohm & ~a25 Chemical Company with 50 parts of an ethylene-et:hyl acrylate copolymer wherein the weight ratio of ~he ethylene fraction to the ethyl acrylate fractio7l is about 4.5 to 1, BAK~.~ITE~ DPD 6169, Union Carbide~ Co~.~any. The dry blend ~-as trznsferred o a ~rocex extr~er and compounded and extruded at 450F. to for~ pellets.
The resulting precGmpounded modiier compo-sition was then blended, and extruded with ~he poly-ester resin, polycarbonate resin, fillers a~d flame retardants, and thereafter injection molded in accord-ance with the p~ocedure described above.
EXAMPL~S l and 2 The following compositions were ~repared by dry blending the ingredients, followed by com~o~nding and extrusion to form pellets. The pellets were injection molded to for~ standard test specimens. The compositions prepared and the results obtained are set forth in Table 1 as follows:
\
., .
, .
"-- : ' ' 5~39t ~22 8CU-3 84 6 TABLE 1: M~ = ~ ~
EXAMPLES A* B** C:*** 1 2 0~ Oy~L ~ -- _ _ Poly(1,4-butylene tere~
phthalate)a- 68.3 68.3 - 68.3 69.8 Polytbis~henol-A
carbonate~ 15.0 15.095.7 15.0 15.0 Acrylate/methacrylate core-shell copolymer c- 15.0 - 3.2 10Ø
Ethylene-ethylacrylate co~olymer d. - - 1.0 5.0 Modifier concentrate e. ~ 15.0 MMBS graft copolymer f- - 15 - - -Stabilizer~/mold release 1.7 1.7 .l 1.7 .2 ~r~Trs 1/8" notched Izod impact strength, ft-lbs/in. 2018.4 14.5 19 19.1 1/8" unnotched Izod impact strength, ft-lb~/in. NBNB NB NB NB
Melt viscosity, poises at 266C. 10,223 8~500 - 8,052 7,600 Tensile elongatio~,% 102 173 ~10 168 173 a. VALOX~ 315, General Electric Company.
b. LEXAN~ 135, General Electric Company c. ACRYLOID~ KM330, Rohm & Haas Chemical Company d. BAKELITE~ DPD 6169, Union Carbide Company.
e. 2:1 w/w ACRYLOID~ KM330, B~KELITE~ DPD 61~9 . B-22, Kanegafuchi Chemi~al Company.
* within th~ scop~ of U.. 4,257,937 to Cohe~ et al.
** within the scope of U.S. 3,864,~28 to Nakumara et al.
*** wi~hi~ the scop~ o~ U.S. 4,260,693 to Liu.
.~
.. .
.. ... . . , ..", ..
.. _.,._.. _ .~ _ .... _.. ~.. ___ _ ~ ._ _,___~ ._ ___ . _ .. _ ._.
percent by weight gr~ftlinking monomer. The preferxed alkyl ac~ylate i5 butyl acrylate. The crosslinking monomeriSa polyethylenically unsaturated m~nomer having a plurality of addition polymerizable .reac~ive groups all of which polymerize a~ substantial.ly the same rate of reaction. Suitable crosslinking monomers include poly acrylic a~d poly ~ethacrylic es~ers o~ polyols sueh as butylene diacrylate and dimethacrylate, ~ri-methylol propane trimethacrylate, and the like, di-and ~rivinyl benzene, vinyl acrylate and methacrylate,and the like. The preferred crosslinking monomer is butylene diacrylate.
The graftlinking monomer is a polyethylenically unsaturated monomer h~ving a plurality of addition polyme~izable reactive groups, at least one of which polymerizes at a substantially different r~te of poly merization from at least one other of saia reactive groups. The function o~ the gxaftlinking monomer is to provide a xesidual level of unsaturation in the elastomeric phase, particularly in the latter staaes of polymerization, and consequently, at or ~ear the suxface of the elastomer particles. When the riyid thermoplastic shell phase is subsequently polymerized at the surface o~ the elastomer, the resi~lal unsaturated, addi~io~;polymerizable reactive group contributed by the graftlinking monomex participates in the ~ubsequent xeaction so that at lea~t a portio~ of the rigid shell phase is chemically attached to th~ surfaçe of the elastom~r~. .
Among the effective graftlinki~g monomers are allyl group-co~taining monomers of allyl esters of ethylenically unsaturated acids, such as allyl acrylate, allyl methacrylate, di llyl maleate J diallyl fumarate, diallyl itaconate, allyl acid maleate, allyl acid fumarate, and allyl aci~ itaconate. Somewhat less .
~2~4 8CU-3846 15 _ O
preferred are the diallyl es~ers of po~.y~a~boxylic acids which do not contain polymerizable unsa~ration. The preerred graftlinking monomers are al~l methacrylat~
and diallyl maleate. A most preferred interpolymer has only two s~ages, the first stage comprising about 60 to 95 percent ~y weight of the interpolym~ and being poly-~erized from a monomer system com~rising 95 to 99 . g ?ercent bv weight butyl acrylate, 0.1 to 2.5 percent by weight butylene diacrylate as crosslIn~ing agent, 0.1 to 2.5 percent ~y weight allyl met~acrylate or diallyl maleate as graCtlinking acent w~th a final stage polymerized from about 60 to 100 percent by weight methacrylate. A pre~erred two stage ir~er?olymer of this type is commercially available unde~ the tradename, ACRYLOID KM 330, from Rohm & Haas Chemi~al Company.
The final or shell stage mon~ner system can be compxised of Cl to Cl6 methacrylate, styrenet acrylo-nitrile, alkyl acrylates, allyl methacrylate, diallyl methacrylate, and the like, as long as ~he overall Tg system is at least 20C. Preerably t~e final stage monomeric system is at least 50 weight ~ercent Cl to C~
alkyl methacrylate. It is further pre'~rred that the final stage polymer be free of units w~,ich tend to degrade poly(alkylene terephthalates), for exam~le~acld, hydroxy~, amino, and amide groups.
The multiphase composite interpolymers are - prepared se~uentially by emulsion polymeriza~ion tech-nique~ whexein each successive outer s~age coats the previous stage polymer. ~y way of illustr~tion, the monomeric Cl-C6 acrylate, the cross-linking monomer and the graft-linking monomer are copolymerized in water i~
the presence of a free-radical generating catalyst and a pol~merization regulator which ser~es as a chain transfer agent, at a temperature on the order of f~om 15Co to 80C~ Th~ first elastomexic ~26258~ 8cu-3846 _16 _ O
phase is formed iIl situ to pro~i~ a latex o~ the core copol~mer.
Therea~ter, the second rigid thermoplastic phase monomers are added and are emulsion polymerized with the core-copolymer latex to form the interpolymers.
A more detailed descriptio~ of the preparation of the inte-polymers for use h~r~in as component ~c)(i) is ound in U.S. 4,034,013, issued June 28, 1977 and U.S.
4,096,202, issued June 20, 1978.
Component ~c)~ii) comprises an olefin resin selected from olef inic homopolymers and copolymers.
The olefin homopolymers are well known and commercially available and may be selected from polyethylene, poly-propylene, polyisobutylene and the like and also may lS be present-in the form of mixtures of these homopolymers.
The preferred homopolymer for use herein i5 polyethylene.
Especial~y preferred for use an olefinic ~: component (c)(ii) herein is a copolymer o~ an olefin and at least one monomeric compound selected from the group consisting of a Cl-C6 alkyl acrylate, a Cl-C6 alkyl m~thacrylate, acrylic cid, methacrylic acid and a mixture of any of the _oresoing.
: Copolymer com~onent (c3lii) is made from ~n olefin, e.~.p ethylene, propylene, or the liXe, copolymerized with one or more of a comonomer comprising a Cl-C6 alkyl acryla~e, e.g., methyl acrylate, ethyl acrylate, hexyl acrylate and the like; a Cl-C6 alkyl me~hacrylate, e.g., methyl methacrylate~ ethyl meth-acrylate, hexyl methacrylate, a~d the like; acrylic acid; or methacrylic ac~d. ~specially preferred are the well known copolymers of Pthyle~e with ~n alkyl ester of acrylic acid. These are disc}osed in U.S.
2,953,551. Generally, the acrylate or methacrylate portion of the c~polymer can range from about lO to abou~30 weight percent. The olefin portion of the :
.: , ~, ~
:: : ~ :.
5~4~
~CU-3846 _ 17~
copolymer can range from about 70 to about 90 weight percent. The preferred copol~mer for use as component (c~(ii) is a~ ethylene~ethyl acrylate copolymer in which the weight ratio of the ethylene fracti~n to the ethyl acrylate fraction is about 4.5 to 1. Suitable olefin-acrylate copolymers, as defined above, can be prepared by methods well known to those skilled in the art or can be ~b~ained co~mercially. E~or example, Union Carbide's BAKELITE~ DPD-6169 ethylene-ethyl 1~ acrylate copolymer is suitable for use in the present invention.
In accordance with a preferred embodiment of the subject invention, modifier combination ~c) is precompounded to ~orm a concentxate which is thereafter admiY.ed with the polyester and polycaxbonate and other additives~
The precompounded composition is pxepaxed by m~lt blending the core-shell interpolymer and the polyolefin or olefin-copolymer in equipment such as a compounding extru~er, rubber mill, Banbury mixer and the like, followed by dicing or pelletizing of the preblended components.
In certain preferred features of he composi-tions will include fillers, especially reinforcing fillers such.as ~ibrous (filamentous~ glass or mineral fillers, such as clay, mica, talc, and the like, pre-ferably clay. The fillers can be untreated or treated with silane or titanate coupling agents, etc. The filamentou~ glass ~o be employed as reinforcement in such embodiments of the present compositions is well known to those skilled in the art and i5 widely available rom a number of manufacturers. For compositions ul~im~tely to be employed for electrical uses, it is pxeferred to use fibrous glass filaments comprise~ of lime-aluminum borosilicate gl2ss that is relatively soda ~L2~
_ 18_ .~ O
free. This is known as "E" glass. However, other glasses are useful where elec~rical properties are not so i~portant, e~g., the low soda glass known as "C" glass. The filaments are made by standard processes, e.g., hy steam or air blowing, flame blowing and mechanical ~ulling. The preferred filaments for plastic rein~orcement are made by mechanical pullins.
The filament diameters range ~rom about 0.00012 to 0O00075 inch, but this is not critical to the present invention, The length of the glass filaments and whether or not they are bundled into fibers and the fibers bundled in turn to yarns, ropes or rovings, or woven into mats, and the like, are also not critical to the invention. Elowever, in preparing the mo].ding compositions, it is convenient to use the filamentous glass in the form of chopped strands of from about one-eighth to about 2 inches longO In articles mo~ded from the compositions, on the othPr hand, even shorter lengths will be encountered besause, during compounding, considerable fragmentation will occur. This is desir-able, however, because the best properties are exhibite~
by thermoplastic injection molded articles in whic~
the filament lenghts lie between abou~ 0.0005 to 0.250 inch.
The amount of the filler can vary widely depending ~n the formulation and needs of the partic-ular composition, it being essen~ial only that an amount is selected which is at leas~ sufficie~ to provide reinforcemen~. Preferably, however, ~he reinforcing fil1er will comprise from about 1 to about 60~ by weight of filler ~d) and components la), (b~ and ~c~
combined.
, ~2~ CU~38~6 _ 19 _ The modified polyester compositions of the presen~ invention, alone, or in combination with a filler or fillers can be ren~ered flame retardant with an effe tive amoun~ of a conventional flame retardant agen~ (e3. As is well known, flame retardants can be based on elementary red phosphorus, phosphorus compounds, halocen and nitrogen co~ounds alone, or preferably in Curther combination with syneraists, such as an~imo:ny com~ounds. Especially useful are polymeric and oli~o-meric flame retardant agents comprising tetrabromobis-phenol-A carbonate units, see, for examp}e, Wambach, U.S.
3,~33,6~, issued September 3, 1974.
Other ingredients such as dyes, pigments, drip retardants and the like can be added in conventi.onal amounts or their conventionally employed purposes.
Generally, the new and improved compositions of the subject invention will comprise fxom about 40 to about 90 parts by weight polyester component (a); from about 10 to about 60 parts by weight aromatic polycarbon-ate component (b); and from about 1 to about 40 parts byweight of modifier combination (c), based upon ~he total weight of components (a), (b) and (c) com~ined~ More particularly,m3clier combination(c) will preferably com-prise from about 5 to about 30 parts by weight of multi-phas~ composite.interpolymer component (c)~ and fromabout 1 p~rt to about 15 parts by weigh~ of olefinic homopolymer or copolymex component (c)(ii), based upon the total weight of the overall composition.
As explained previously, the modifier combina~
tion, or preferably the modifier concentrate, is .admixed with the other ingredients of the final composi-tionO This can be done in one conve~ient manner by tumbling the concentrate and other components to form a dry hlend, extruding the blend at a temperature 3S between 450 to S50F, cooling the ex~ruda~e, orming it . .
.
L' ~
8CU~3846 _ ~0 O
into pellets and injection moldinq at ~ te~perature of 450 to 550F. (50 to 250F. mold temperature~.
The new and improved modi~ie~ polyester composition~ of the present inventio~ e~hibit decr~ased melt viscosity and improved melt flow ~endering them well suited ~or use in injection mold~-ng a;pplications.
In the preferred embodiment ~herein th~ modifier combination is present as a precompounded co~.?osi~ion, the acrylate/methacrylate core-shell c~polymer powder~
a-e ~etted and pre-~elletized with the ~ol~olefin resin, resin blend or copolyr.er resin which e~ectively reduces o- removes the hazards associated with ~lending or bulk blending these rubber particles with o~her resinous polymeric components. The modi~er co~c~ntrate provides a pre-dispersed impact modifier, which when blended with t:~e po'yester a~d polyca~bonate resins, is more easily and ~ffectively dis~ersed throughout, which provides better part appearance and tensile elongation while the Lmpact strength is retained.
In order that those skilled in the art may better understand how the present inve~tion may be practiced, the following examples are given by way of illustration and not by way o~ limitatlon.
D CRIPTION OF THE PREFERRE~ EMBODIMENTS
In the following examples, æll parts and perce~tages are by weiyht unless otherwis~ noted. The various polyester compositions were ~irst dry blended~
the~ compounded and extruded in a Proaex extrud~ at 500F. and finally molded in a Van Dorm injection moldiny machine at 480F. to form tes~ specimens. The test specimens were molded to form ASTM test bars of 2~" x 1/~" x 1/8" dimensions. Resistance to impact failure of the specimens was determined i~ accordance with the Notched Izod Impact Te~t, ASTM D256 on both notched and unno~ched specimens.
~:6~8~ ~cu-3846 A precompounded concentra~e was p~epared by tumblin~ 100 parts of an acrylate/methzlcrylate core-shell copolymer~ ACRYLOID KM 330, Rohm & ~a25 Chemical Company with 50 parts of an ethylene-et:hyl acrylate copolymer wherein the weight ratio of ~he ethylene fraction to the ethyl acrylate fractio7l is about 4.5 to 1, BAK~.~ITE~ DPD 6169, Union Carbide~ Co~.~any. The dry blend ~-as trznsferred o a ~rocex extr~er and compounded and extruded at 450F. to for~ pellets.
The resulting precGmpounded modiier compo-sition was then blended, and extruded with ~he poly-ester resin, polycarbonate resin, fillers a~d flame retardants, and thereafter injection molded in accord-ance with the p~ocedure described above.
EXAMPL~S l and 2 The following compositions were ~repared by dry blending the ingredients, followed by com~o~nding and extrusion to form pellets. The pellets were injection molded to for~ standard test specimens. The compositions prepared and the results obtained are set forth in Table 1 as follows:
\
., .
, .
"-- : ' ' 5~39t ~22 8CU-3 84 6 TABLE 1: M~ = ~ ~
EXAMPLES A* B** C:*** 1 2 0~ Oy~L ~ -- _ _ Poly(1,4-butylene tere~
phthalate)a- 68.3 68.3 - 68.3 69.8 Polytbis~henol-A
carbonate~ 15.0 15.095.7 15.0 15.0 Acrylate/methacrylate core-shell copolymer c- 15.0 - 3.2 10Ø
Ethylene-ethylacrylate co~olymer d. - - 1.0 5.0 Modifier concentrate e. ~ 15.0 MMBS graft copolymer f- - 15 - - -Stabilizer~/mold release 1.7 1.7 .l 1.7 .2 ~r~Trs 1/8" notched Izod impact strength, ft-lbs/in. 2018.4 14.5 19 19.1 1/8" unnotched Izod impact strength, ft-lb~/in. NBNB NB NB NB
Melt viscosity, poises at 266C. 10,223 8~500 - 8,052 7,600 Tensile elongatio~,% 102 173 ~10 168 173 a. VALOX~ 315, General Electric Company.
b. LEXAN~ 135, General Electric Company c. ACRYLOID~ KM330, Rohm & Haas Chemical Company d. BAKELITE~ DPD 6169, Union Carbide Company.
e. 2:1 w/w ACRYLOID~ KM330, B~KELITE~ DPD 61~9 . B-22, Kanegafuchi Chemi~al Company.
* within th~ scop~ of U.. 4,257,937 to Cohe~ et al.
** within the scope of U.S. 3,864,~28 to Nakumara et al.
*** wi~hi~ the scop~ o~ U.S. 4,260,693 to Liu.
.~
.. .
.. ... . . , ..", ..
.. _.,._.. _ .~ _ .... _.. ~.. ___ _ ~ ._ _,___~ ._ ___ . _ .. _ ._.
6~ ~ 8Cu-3846 _23 _ ThesP data illustrate the improvem~nts in the melt viscosity and tensile elongation and retained impact strength obtained with the new and impro~ed ~odi-fied polyes~er compositions of the subject inventio~.
For example, the compositions of Examp.les A and 1 exhibit ~llbstantially similar impac~ strength prope~ties, ho~.?e~er, E~am?le 1 also exhibI~s significantly lowe~ melt viscosity anZ higher tensile elongation. The prior art composition of Example B containing a simple grafte~
~L~3S co~olymer exhibits good impact strength, melt viscosity and tensile elongation, however, after thermal aging of these Example B compositions, both the impact strength and tensile elongation decline --- - due to the lnherent poa~
lS thermal stability of the MMBS graft copolymer, as com-pared with aged CompOSitiQns o~ ~xamples 1 and 2 cc~tain-ing the acrylatetmethacrylate cQre-shell copolymer and olefin copolymer resins of the subject invention w~ich exhibit good thermal stability. The prior art composi-tions of Example C based on polycarbonate alone ex~ibitpoorer impact strength and tensile elongation, and in addition, due to the art-recosnized poor solvent resis-tance of aromatic polycarbonate resins, e~hibit poc~er solven~ resistance to unleaded gasoline and other ~olvents 2S compared with the polyester-containing compositivns of thi~ invention shown in Examples 1 and 2.
~ oreover, the use of the precompounded m~di-fier composition of the present invention, shown by ; Example 2,.provided a composition that exh~ited i~lproved melt flow, thereby providing a thermoplastlc composition having improved processability, moldability and ex~ rud-ability. The compositions Oc Example ~ also exhib~ted imp~oved tensile elongation. T~ese properties wer~ obtained using less of the acrylate/methacryl~te core-shell copolymer resin. In addition, parts mo~ded .
S~
from the composition of Example 2 shows no striations or color spots indicating more uniform dispersion and better appearance than those compositions containing unprecompounded modifiers.
Although the present invention has been described with reference to certain preferred embodiments, many obvious modifications may be made therein or will suggest themselves to those skilled in this art. For example, and as already mentioned, copolyesters and block copolyesters may be substituted in whole or in part for the poly(l,~-butylene terephthalate) resin component (a). Instead of a bisphenol-A polycarbonate, one containing units derived from tetramethylbisphenol~A
or from dixylenol sulfone can be used as component (b~.
Instead of a multiphase composite (e.g., core-shell) interpolymer having an n-butyl acrylate core, one having an ethyl acrylate core could be used. Instead of an ethylene-ethyl acrylate copolymer, a blend of polyethylene and polyisobutylene could be used; or propylene may be substituted in the copolymer for the olefin component; or there can be used copolymers of ethylene and methyl methacrylate, ethylene and acrylic acid and ethylene and methacrylic acid, to name but a few of the variations possible. All such obvious modifications are within the scope and spirit of the present invention as de~ined by the appended claims.
: ~.
For example, the compositions of Examp.les A and 1 exhibit ~llbstantially similar impac~ strength prope~ties, ho~.?e~er, E~am?le 1 also exhibI~s significantly lowe~ melt viscosity anZ higher tensile elongation. The prior art composition of Example B containing a simple grafte~
~L~3S co~olymer exhibits good impact strength, melt viscosity and tensile elongation, however, after thermal aging of these Example B compositions, both the impact strength and tensile elongation decline --- - due to the lnherent poa~
lS thermal stability of the MMBS graft copolymer, as com-pared with aged CompOSitiQns o~ ~xamples 1 and 2 cc~tain-ing the acrylatetmethacrylate cQre-shell copolymer and olefin copolymer resins of the subject invention w~ich exhibit good thermal stability. The prior art composi-tions of Example C based on polycarbonate alone ex~ibitpoorer impact strength and tensile elongation, and in addition, due to the art-recosnized poor solvent resis-tance of aromatic polycarbonate resins, e~hibit poc~er solven~ resistance to unleaded gasoline and other ~olvents 2S compared with the polyester-containing compositivns of thi~ invention shown in Examples 1 and 2.
~ oreover, the use of the precompounded m~di-fier composition of the present invention, shown by ; Example 2,.provided a composition that exh~ited i~lproved melt flow, thereby providing a thermoplastlc composition having improved processability, moldability and ex~ rud-ability. The compositions Oc Example ~ also exhib~ted imp~oved tensile elongation. T~ese properties wer~ obtained using less of the acrylate/methacryl~te core-shell copolymer resin. In addition, parts mo~ded .
S~
from the composition of Example 2 shows no striations or color spots indicating more uniform dispersion and better appearance than those compositions containing unprecompounded modifiers.
Although the present invention has been described with reference to certain preferred embodiments, many obvious modifications may be made therein or will suggest themselves to those skilled in this art. For example, and as already mentioned, copolyesters and block copolyesters may be substituted in whole or in part for the poly(l,~-butylene terephthalate) resin component (a). Instead of a bisphenol-A polycarbonate, one containing units derived from tetramethylbisphenol~A
or from dixylenol sulfone can be used as component (b~.
Instead of a multiphase composite (e.g., core-shell) interpolymer having an n-butyl acrylate core, one having an ethyl acrylate core could be used. Instead of an ethylene-ethyl acrylate copolymer, a blend of polyethylene and polyisobutylene could be used; or propylene may be substituted in the copolymer for the olefin component; or there can be used copolymers of ethylene and methyl methacrylate, ethylene and acrylic acid and ethylene and methacrylic acid, to name but a few of the variations possible. All such obvious modifications are within the scope and spirit of the present invention as de~ined by the appended claims.
: ~.
Claims (9)
1. 1. A resin mixture exhibiting improved impact properties and processability comprising:
(a) From 40 to about 85 parts by weight of a polyester resin composition comprising:
(i) a poly(alkylene terephthalate) resin;
(ii) a blend of poly(1,4-butylene terephthalate) resin and a poly(ethylene terephthalate) resin;
(iii) a block copolymer of poly(1,4-butylene terephthalate) and an aromatic/
aliphatic or aliphatic polyester;
(iv) a blend of (iii) and a poly(1,4-butylene terephthalate) resin;
(b) from 10 to 60 parts by weight of an aromatic polycarbonate resin which comprises recurring structural units of the formula wherein A is a divalent aromatic radical of a dihydric phenol; and (c) from 1 to 40 parts by weight of an impact modifier combination therefore, said modifier combination comprising:
(i) a multiphase composite core-shell interpolymer component comprising a first elastomeric core stage of a C1-C6 alkyl acrylate, a crosslinking monomer and a rigid thermoplastic final stage comprising at least about 50% by weight of C1-C6 alkyl methacrylate; and (ii) an olefinic resin selected from the group consisting of a C1-C10 olefin homopolymer, copolymers of a said olefin with at least one monomeric compound selected from a C1-C6 alkyl acrylate, a C1-C6 alkyl methacrylate, acrylic acid, and methacrylic acid, and mixtures of the foregoing olefinic resins.
(a) From 40 to about 85 parts by weight of a polyester resin composition comprising:
(i) a poly(alkylene terephthalate) resin;
(ii) a blend of poly(1,4-butylene terephthalate) resin and a poly(ethylene terephthalate) resin;
(iii) a block copolymer of poly(1,4-butylene terephthalate) and an aromatic/
aliphatic or aliphatic polyester;
(iv) a blend of (iii) and a poly(1,4-butylene terephthalate) resin;
(b) from 10 to 60 parts by weight of an aromatic polycarbonate resin which comprises recurring structural units of the formula wherein A is a divalent aromatic radical of a dihydric phenol; and (c) from 1 to 40 parts by weight of an impact modifier combination therefore, said modifier combination comprising:
(i) a multiphase composite core-shell interpolymer component comprising a first elastomeric core stage of a C1-C6 alkyl acrylate, a crosslinking monomer and a rigid thermoplastic final stage comprising at least about 50% by weight of C1-C6 alkyl methacrylate; and (ii) an olefinic resin selected from the group consisting of a C1-C10 olefin homopolymer, copolymers of a said olefin with at least one monomeric compound selected from a C1-C6 alkyl acrylate, a C1-C6 alkyl methacrylate, acrylic acid, and methacrylic acid, and mixtures of the foregoing olefinic resins.
2. A resin mixture as defined in claim 1, wherein in said modifier combination, component (c), the multiphase composite interpolymer (c)(i) comprises from about 5 to about 30 parts by weight and olefinic resin component (c)(ii) comprises from about 1 to about 15 parts by weight, based upon the weight of the overall composition.
3. A resin mixture as defined in claim 1 wherein said polyester component (a) is a poly(1,4-butylene terephthalate) resin.
4. A resin mixture as defined in claim 1, wherein in said formula, A is derived from a 4,4'-dihydroxy-di(mononuclear aryl) alkane.
5. A resin mixture as defined in claim l, wherein said aromatic polycarbonate resin (b) comprises poly(2,2-dihydroxydiphenylpropane) carbonate.
6. A resin mixture as defined in claim 1, wherein said multiphase composite interpolymer component (c)(i) comprises a first elastomeric core phase of n-butyl acrylate with a butylene diacrylate crosslinking agent and an allyl methacrylate graft-linking agent and a hard final phase of methyl methacrylate.
7. A resin mixture as defined in claim 1, wherein said copolymer component (c)(ii) comprises a copolymer of ethylene and ethyl acrylate.
8. A resin mixture exhibiting improved impact resistance and processability comprising:
(a) From 40 to 85 parts by weight of a polyester composition comprising:
(i) a poly(alkylene terephthalate) resin;
(ii) a blend of poly(l,4-butylene terephthalate) resin and a poly(ethylene terephthalate) resin;
(iii) a block copolymer of poly(l,4-butylene terephthalate) and an aromatic/aliphatic or aliphatic polyester;
(iv) a blend of (iii) and a poly(1,4-butylene terephthalate) resin;
(b) from 10 to 60 parts by weight of an aromatic polycarbonate resin which comprises recurring structural units of the formula wherein A is a divalent aromatic radical of a dihydric phenol; and (c) from 1 to 40 parts by weight of an precompounded modifier composition comprising:
(i) a multiphase composite core-shell interpolymer component comprising a first elastomeric core stage of a C1-C6 alkyl acrylate, a crosslinking monomer and a rigid thermoplastic final stage comprising at least about 50% by weight of C1-C6 alkyl methacrylate; and (ii) an olefinic resin selected from the group consisting of C1-C10 olefin homopolymers, copolymers of a said olefin with at least one monomeric compound selected from C1-C6 alkyl acrylate, a C1-C6 alkyl methacrylate, acrylic acid and methacrylic acid and mixtures of the foregoing olefinic resins.
(a) From 40 to 85 parts by weight of a polyester composition comprising:
(i) a poly(alkylene terephthalate) resin;
(ii) a blend of poly(l,4-butylene terephthalate) resin and a poly(ethylene terephthalate) resin;
(iii) a block copolymer of poly(l,4-butylene terephthalate) and an aromatic/aliphatic or aliphatic polyester;
(iv) a blend of (iii) and a poly(1,4-butylene terephthalate) resin;
(b) from 10 to 60 parts by weight of an aromatic polycarbonate resin which comprises recurring structural units of the formula wherein A is a divalent aromatic radical of a dihydric phenol; and (c) from 1 to 40 parts by weight of an precompounded modifier composition comprising:
(i) a multiphase composite core-shell interpolymer component comprising a first elastomeric core stage of a C1-C6 alkyl acrylate, a crosslinking monomer and a rigid thermoplastic final stage comprising at least about 50% by weight of C1-C6 alkyl methacrylate; and (ii) an olefinic resin selected from the group consisting of C1-C10 olefin homopolymers, copolymers of a said olefin with at least one monomeric compound selected from C1-C6 alkyl acrylate, a C1-C6 alkyl methacrylate, acrylic acid and methacrylic acid and mixtures of the foregoing olefinic resins.
9. A resin mixture as defined in claim 8 wherein polyester composition (a) comprises a poly(1,4-butylene terephthalate) resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000469642A CA1262584A (en) | 1983-08-19 | 1984-12-07 | Modified polyester composition |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US52482583A | 1983-08-19 | 1983-08-19 | |
| CA000469642A CA1262584A (en) | 1983-08-19 | 1984-12-07 | Modified polyester composition |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1262584A true CA1262584A (en) | 1989-10-31 |
Family
ID=4129329
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000469642A Expired CA1262584A (en) | 1983-08-19 | 1984-12-07 | Modified polyester composition |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1262584A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114989405A (en) * | 2022-07-11 | 2022-09-02 | 青岛大学 | Titanium catalyst for synthesizing polyester by DMT method, preparation method and application thereof |
-
1984
- 1984-12-07 CA CA000469642A patent/CA1262584A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114989405A (en) * | 2022-07-11 | 2022-09-02 | 青岛大学 | Titanium catalyst for synthesizing polyester by DMT method, preparation method and application thereof |
| CN114989405B (en) * | 2022-07-11 | 2024-02-20 | 青岛大学 | Titanium catalyst for synthesizing polyester by DMT method and preparation method and application thereof |
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