CA1148291A

CA1148291A - Reinforced thermoplastic molding compositions

Info

Publication number: CA1148291A
Application number: CA000330878A
Authority: CA
Inventors: Frank N. Liberti; Allen D. Wambach
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1978-07-19
Filing date: 1979-06-29
Publication date: 1983-06-14
Also published as: EP0016123A4; WO1980000255A1; JPS55500524A; EP0016123A1

Abstract

ABSTRACT OF THE INVENTION
An improved reinforced thermoplastic molding composition is provided, the composition comprising a thermoplastic resin selected from the group consisting of a high molecular weight linear polyester, a mixture of high molecular weight linear polyester, a mixture of high molecular weight linear polyesters, a mixture of a high molecular weight linear polyester and high molecular block copolyester and a mixture of high molecular weight linear polyester and high molecular weight block copolyester, fibrous glass reinforcement, phlogopite mica and an impact modifier. The compositions are moldable to articles having improved resistance to warpage, high deflection temperature under load (DTUL) and high impact strength.

Description

~ 8 CH~2654 This invention relates to glass reinforced molding compositions which have improved warp resistance, high deflection temperature under load (DTUL) and high impact strength in the molded article. More particularly, it pertains to compositions comprising a thermoplastic resin selected from the group consisting of a high molecular weight linear polyester, a mixture of high molecular weight linear polyesters, a mixture of a high molecular weight linear polyester and high molecular weight block polyester and a mixture of high molecular weight linear polyesters and high molecular weight block copolyester, fibrous glass reinforcement, phlogopite mica and an impact modifier.
With the developement of molecular weight control, the use of nucleating agents and two-step molding cycles, poly-(ethylene terephthalate) has become an important constituent of injection moldable compositions. Poly(l, 4-butylene terephthalate), because of its very rapid crystallization from the melt, is uni~uely useful as a component in such compositions. Workpieces molded from such polyester resins, in comparison with other thermoplastics, offer a high degree of surface hardness and abrasion resistance, high gloss, and lower surface friction.
It has been previously disclosed in Canadian Application Serial No. 273,776 - filed March 11, 1977, assigned to the same assignee as herein, that glass reinforced thermoplastic compositions of a polycarbonate resin and poly(l,4-butylene terephthalate) can be molded to articles having greater resistance to warpage and/or improved DTUL, in comparison with glass fiber reinforced poly(1,4-butylene terephthalate) resins. It is further disclosed in Canadian Application Serial No. 292,804 filed December 9, 1977, assigned to the same assignee as herein, -- 1 i ~ 8 CH-Z654 that zinc stearate when added to polyester polyblends elevates notched Izod impact strength, while maintaining unnotched impact strength, flexural strength and tensile strength and dramatically reduces sample-to-sample variability in elongation. Also, it is disclosed in Canadian Application Serial No. 292,793 - filed December 9, 1977, and assigned to the same assignee as herein, that glass fibers in combination with a mineral filler provide molded articles with improved DTUL and/or reduced warpage.
In addition, it is disclosed in Canadian Application Serial No. 291,779 - filed November 25, 1977, assigned to the same assignee as herein, that compositions comprising poly( butylene terephthalate), poly(ethylene terephthalate), a polycarbonate and glass fiber have increased DTUL and/or reduced warpage. It is disclosed in Canadian Application Serial No. 299,155 filed March 17, 1978, that blends of a poly(l,4-butylene terephthalate) resin and a polycarbonate resin reinforced with fibrous glass, when admixed with a small amount of zinc stearate possess even less inherent ZO warpage in the molded article and good moldability when compared with compositions of glass fiber reinforced poly( 1,4-butylene terephthalate).
It has now been discovered that compositions of high molecular weight linear polyesters, optionally in admixture with block copolyesters, fibrous glass reinforce-ment, phlogopite mica and an impact modifier possess very little inherent warpage in the molded article and, in addition, are characterized with good impact strength and high deflection temperature under load (DTUL).

According to this invention, there are provided reinforced thermoplastic compositions having increased resistance to warpage, as well as high deflection ~8.~ 8 C~I-2~54 temperature under load (DTUL~ and good impact strength, useful for molding, e.g., injection molding, compression molding, transfer molding, wire coating and the like, the composition comprising:
(a) a thermoplastic resin selected from the group consisting of a high molecular weight linear polyester, pol y e st~s, a mixture of high molecular weight linear pol~estcr, a mixture of a high molecular weight linear polyester and high molecular weight block copolyester and mixtures of high molecular weight linear polyesters and high molecular weight block copolyester wherein said block copolyester is derived from blocks of (i) a terminally-reactive poly(l,4-butylene tere-phthalate) and (ii) a terminally-reactive aromatic/aliphatic copolyester of a dicarboxylic acid selected from the group consisting of terephthalic acid, isophthalic acid, naphthalene dicarboxylic acids, phenyl indane dicarboxylic acid and compounds of the formula:
O

HO C ~ - X ~ ~ C OH

in which X may be alkylene or alkylidene of from l to 4 carbon atoms, carbonyl, sulfonyl, oxygen or a bond between the benzene rings, and an aliphatic dicarboxylic acid having from ~ to 12 carbon atoms in the chain and one or more straight or branched chain dihydric aliphatic glycols having from ~ to 10 carbon atoms in the chain, said copolyester having at least 10% of aliphatic units being derived from a dicarboxylic acid, or ~ 8 CH-2~4 (iii) a terminally-reactive aliphatic polyester of a straight chain aliphatic dicarboxylic acid having from 4 to 12 carbon atoms in the chain and a straight or branched chain aliphatic glycol, said blocks being connected by inter terminal linkages consisting essentially of ester linkages;
(b) an impact modiEier:
(c) fibrous glass reinforcement; and -(d) phlogopite mica The high molecular weight linear polyesters of this invention include, in general, linear saturated condensation products of diols and dicarboxylic acids, or reactive derivatives thereof. Preferably, they will comprise condensation products of aromatic dicarboxylic acids and aliphatic diols. Although the diol portion of the polyester can contain from two to ten carbon atoms, it is preferred that it contain ~rom two to four carbon atoms in the form of linear methylene chains. It is to be understood that it is also possible to use polyesters such as poly(1,4-dimethylol cyclohexane dicarboxylates, e.g., terephthalates). In addition to phthalates, small amounts of other aromatic dicarboxylic acids, such as naphthalene dicarboxylic acid, or aliphatic dicarboxylic acids, such as adipic acid, can also be present in preferred compositions. The diol constituent can likewise be varied, in the preferred embodiments, by addin~ small amounts of cycloaliphatic diols, such as cyclohexanedimethanol. In any event, the preferred polyesters are well known as film and fiber formers, and they are provided by methods outlined in U.S. Patent No.

2,465,319 - dated March 22, 1949 - Whinfield and U.S. Patent No. 3,047,539 - dated ~uly 31, 1962 - Pengilly and elsewhere. The preferred polyesters will comprise a poly(alkylene terephthalate), isophthalate or mixed ~8~9~ 8CH 2~54 lsophthalate- terephthalate, e.g., up to 30 mole percent isophthalate, said alkylene groups containing from 2 to 10 carbon atoms, e.g., poly(ethylene terephthalate) or poly ~1,4-butylene terephthalate). Because of its rapid crystallization from the melt, it is preferred to use poly(l,4-butylene terephthalate) as the linear polyester resin component of the present compositions. Also, contem-plated within the scope of this invention are the use of mixtures of linear polyesters, such as a mixture of poly ~0 (ethylene terephthalate) and poly(l,4-butylene terephthalate).
When these mixtures are utilized the poly(ethylene tere-ph halate) can be used in amounts of from about 1-40~ by weight, preferably 15-30% by weight of the total composition.
The "block copolyesters" also useful in the compositions of this invention are prepared by the reaction of terminally-reactive poly(butylene-terephthalate), preferably, low molecular weight, and a terminally-reactive copolyester of polyester in the presence of a catalyst for transesterification, such as zinc acetate, manganese acetate, titanium esters, and the like. The terminal groups are hydroxyl, carboxyl, carboalkoxy, and the like, including reactive derivatives thereof. The result of reaction between two terminally reactive groups, of course, must be an ester linkage. ~fter initial mixing, polymerization is carried out under standard conditions, e.g., 220 to 280C.
in a high vacuum, e.g., 0.1 to 2 mm Hg, to form the block copolymer of minimum randomization in terms of distribution of chain segments.
The copolyester designated component ~ii), herein-above, is preferably prepared from terephthalic acid or isophthalic acid or a reactive derivative thereof and a _ 5 _ ~ ~, ~ 8 CH 26~4 glycol, which may be a straight or branched chain aliphatic glycol. Illustratively, the glycol will be 1, 4-butanediol; 1,5-pentanediol; 1,6-hexanediol;
l,9-nonanediol; 1,10-decanediol; neopentyl glycol;
1,4-cyclochexanediol; 1,4-cyclohexane dimethanol, a mixture of any of the foregoing, or the like. Illustrative of suitable aliphatic dicarboxylic acids for the mixed aromatic/
aliphatic embodiments are suberic, sebacic, azelaic, adipic acids, and the like.
The copolyesters may be prepared by ester interchange in accordance with standard procedures. The copolyesters designated (ii) are most preferably derived from an aliphatic glycol and a mixture of aromatic and aliphatic dibasic acids in which the mole ratio concentration of aromatic to aliphatic acids is from between 1 to 9 and 9 to 1, with an especially preferred range being from about

3 to 7 to about 7 to 3.
The terminally reactive aliphatic polyesters desig-nated component (iii) will contain substantially stoichiometric amounts of the aliphatic diol and the aliphatic dicarboxylic acid, although hydroxy-containing terminal groups are preferred.
in addition to their ease of formation by well-known procedures, both the aromatic/aliphatic copolyesters (ii) and the alphatic polyesters (iii) are commercially available. One source for such materials is the Ruco Division/Hooker Chemical Company, Hicksville, New York, which lM
7 designates its compounds as "Rucoflex".
The block copolyesters contemplated herein preferably comprise from 95 to 50 parts by weight of the segments of poly(l,4-butylene terephthalate). The poly( 1,4-butylene terephthalate) blocks, before incorporation into the block copolyesters, will preferably have an ~ 8 CH 2654 intrinsic viscosity of above 0.1 dl./g. and preferably, between 0.1 and 0.5 dl./g., as measured in a 60:40 mixture of phenol/tetrachloroethane at 30 C. The balance, 5 to 50 parts by welght of the copolyester will comprise blocks of components (ii) or (iii).
As will be understood by those skilled in the art, the poly(l,4-butylene terephthalate) block can be straight chain or branched, e.g., by use of a branching component, e.g., 0.05 to 1 mole %, based on terephthalate units, of a branching component which contains at least three ester-forming groups. This can be a glycol, e.g., pentaerythritol, trimethylolpropane, and the like, or a polybasic acid compound, e.g., trimethyl trimesate, and the like.
Among the impact modifiers included within the scope of the present compositions are segmented copolyester-~ r~
ethers known as Hytrel (duPont), silicone-polycarbonate block copolymer, e.g., Copel 3320 (G.E.) and ethylene-vinyl .~
acetate copolymers (Alathon, by duPont). In addition, a mixture of ethylene-vinyl acetate copolymer and polyethylene homopolymer is useful. In general, the impact modifier is present in the composition of this invention in amounts within the range of from about 1 to 20%, by weight, preferably 1-15%, by weight, of the total composition.
The segmented copolyester-ethers useful as impact modifiers herein are described in U.S. Patent No.
3,023,182 - dated February 27, 1962 - Tanabe et al, U.S.
Patent No. 3,651,014 - dated March 21, 1972 - Witsiepe, U.S. Patent No. 3,763,109 - dated October 2, 1973 -Witsiepe and U.S. Patent No. 3,766,146 - dated October 16, 1973 - Witsiepe. Typical copolymers of ethylene and vinyl acetate include, for example, Alathon 3152 (15% by weight vinyl content), Alathon 3194 (25~ by weight vinyl acetate), ~ 8 CH 2654 -~ Alathon 3180 (28% by weight vinyl acetate), Vynathene EY 903, (45% by weight vinyl acetate, sold by U.S.I.
Chemicals) and Vynathene EY 904 (52% by weight vinyl acetate).
It has been observed that copolymers of ethylene and vinyl acetate impart more impact enhancement when used in conjunction with polyethylene homopolymer.
The fibrous glass employed as component (c) in the present compositions is well known to those skilled in the art and is widely available from a number of manufacturers. For compositions ultimately to be employed for electrical use, it is preferred to use fibrous glass filaments comprised of lime-aluminum borosilicate glass that is relatively soda free. This is known as "E" glass.
However, other glasses are useful where electrical properties are not so important, e.g., the low soda glass known as "C" glass. The filaments are made by standard processes, e.g., by steam or air blowing, flame blowing and mechanical pulling. The preferred filaments for plastics reinforcement are made by mechanical pulling. The filament diameter range from about 0.00012 to 0.00075 inch, but this is not critical to the present invention.
The length of the glass filaments and whether or not they are bundled into fibres 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. However, in preparing the molding compositions, it is convenient to use the filamen'cous glass in the form of chopped strands of from about one-eight to about 2 inches long. In articles molded from the compositions, on the other hand, even shorter lengths will be encountered because, during compounding, considerable fragmentation will occur. This is desirable, however, because the best properties are exhibited by ~ 2~1 ~ C~l 2654 thermoplastic injection moldea articles in ~hich the filament lengths lie between about 0.0001 ~n~ 0.125 (one-eighth) inch.
For the purposes of this invention, the fibrous glass reinforcement and the phlogopite mica are employed in a combined amount of from about 1 to about 60% by weight, of the total composition, the preferred range being from about 25 to about 40% by weight.
The phIogopite mica used in the practice of the present invention has a particle size of from about 10-325 mesh. Particularly preferred phlogopite micas are commercially available from Marietta Resources, Ltd. Montreal, f~
B and are known as Suzorite (20H, 10-20 mesh; 200 H, less - than 100 mesh; 200 S, less than 100 mesh; 150 S, less than 100 mesh, 80 S, 99% less than 100 mesh. Among these, the most preferred, from a standpoint of conferring the best combination of properties, appears to be Suzorite 150 S.
Other materials which may also be included in the compositions of the present invention in conjunction with the heretofore identified impact modi~iers, include polyethylene copolymers, like ethylene-propylene copolymers, ethylene-ethylene acrylate copolymers and ethylene-acrylic acid salt copolymers. Further optional materials include flame retardants like decabromodiphenyl ether and nalogenated aromatic polycarbonates. Illustrative flame- -retardant additives are disclosed in U.S. Patent No. 3,833,685 dated September 3, 1974 - Wambach, U.S. Patent No.3,195,926 - dated July 20, 1965 - Hirsch and U.S. Patent No.3,671,487 -- dated June 20, 1972 - Abolins. Other flame retardants are disclosed in U.S. Patent No. 3,681,281 - dated AU~'~lSi 1, 1972 - Juelke et al and U.S. Patent No.3,557,053 - dated January 19, 1971 - Miller, U.S. Patent 3,830~771 ~ 8CH 2654 - dated August 20, 1974 - Cohen et al.
The flame retardants are generally utilized in any flame retardant quantity whereas the other optional ingredients like polyethylene, can be used in amounts of from about 0.5 to 5% by weight of the total composition or in any conventional amounts for the purposes intended.
The compositions of this invention can be prepared by a number of procedures. In one way, the fibrous glass reinforcement, phlogopite mica and impact modifier are dispersed in a matrix of the resin in the process. In another procedure the glass reinforcement, phlogopite mica and impact modifier are mixed with, for example, the poly( 1,4-butylene terephthalate) resin by dry blending, then either fluxed on a mill and comminuted, or they are extruded and chopped. The glass reinforcing agent, phlogopite mica and impact modifier can also be mixed with the resin and directly molded, e.g., by injection or transfer molding A techniques.
Although it is not essential, best results are obtained if the ingredients are pre-compounded, pelletized and then molded. Pre-compounding can be carried out in conventional equipment. For example, after carefully pre-drying the polyester, e.g., at 125C. for 4 hours, a single screw extruder is fed with a dry blend of the ingredients, the screw employed having long transition and metering sections to ensure proper melting. On the other hand, a twin screw extrusion machinet e.g., a Werner & Pfleiderer machine, can be fed with resins and additives at the feed port and reinforce-30 ment downstream. In either case, a generally suitable machine temperature will be about 450 to 570F.

~ 8 CH~2654 The pre-compounded composition can be extruded and cut up into molding compounds such as conventional granules, pellets, etc., by standard techniques.
The compositions can be molded in any equipment conventionally used for glass-filled thermoplastic compositions, e.g., a Van Dorn type injection molding machine with conventional cylinder temperatures, e.g., 525F, and conventional mold temperatures, e.g., 150F.

The following examples illustrate the invention.
They are set forth as a further description but are not to be construed as limiting the invention thereto.
Examples 1 - 5 The following formulations are mechanically blended, then extruded and molded into test pieces in a Van Dorn injection molding machine. The properties are also summarized in the following table.
Table 1 Example _ 2* 3* 4 5_ _ _ Ingredients (parts by weight~
i ~ VALOX 300 63.7 58.7 43.7 51.2 46.2 Fibrous glass reinforcement 11 11 11 11 11 English mica C-1000 <325 mesh 25 25 25 -- --Suzorite mica 20H -- -- - 25 25 Copel 3320b -- 5 20 12.5 17.5 Mold release agentC 0.10 0.10 0.10 0.10 0.10 Irganox 1093 0.15 0.15 0.15 0.15 0.15 Ferro 904 0.05 0-05 0.05 0.05 0.05 Properties ~arpage R. T. (mm) 10 5 2 0 0 Warpage 350 F/3~
min,(mm~ 16 11 7 <1 ~1 ~ 8 CH-2654 Table 1 cont'd Warpage 300 F/30 min, (mm) 13 9 2 <1<1 Notched Izod Impact, ft. lb/in. 0.66 0.80 1.36 1.30 1.54 ~nnotched Izod Impact, ft. lb/in. 6.4 7.0 8.6 4.7 5.2 DTUL at 264 psi, F 416 387 321 370 336 * Control (a) poly(l,4-butylene terephthalate) intrinsic viscosity 0.9 measured in aOsolution of phenol and tetrachloroeth-ane (60:40) at 3Q C.
(b) silicone-polycarbonate block copolymer (GE) .~
(c) Mold Wiz (Int. EQ-6) (d) tetrakis (3,5-di-t-butyl-4 hydroxyphenylpropionyloxy methyl)methane (e) diphenyl decylphosphite The above data clearly show the remarkable warp resistance of the compositions of this invention which employ phlogopite mica (Suzorite), as well as the good impact strength and DTUL, in comparison with similar compositions containing muscovite mica (English mico C-1000).
Examples 6 - 9 The following formulations are mechanically blended, then extruded and molded into test pieces in a Van Dorn injection molding machine. The properties of the compositions are also summarized in Table 2.
Table 2 Example Ingredients (parts by weight) 6 7 8 9 VALOX 300 48.7 51.7 28.7 31.7 fibrous glass reinforcement 11.0 11.0 11.0 11.0 Suzorite mica 20H 25.0 25.0 25.0 25.0 Hytrel 4056 15.0 10.0 15.0 10.0 ~ 2~1 i3 ~
Table 2 cont'd Microthene FN-51D
(polyethylene) -- 2.0 -- 2.0 poly(ethylene 2 terephthalate) -- -- 20.0 20.0 Irganox 1093 (antioxidant) 0.15 0.15 0.15 0.15 Ferro 904 (antioxidant) 0.05 0.05 0.05 0.05 Mold Wiz (mold release agent) 0.10 0.10 0.10 0.10 _operties Warpage R. T . (mm) 0 0 0 0 Warpage 350 F/30 min.(mm) 0 <1 <1 o Warpage 300 F/30 min (mm) 0 0 1 0 Notched Izod Impact Impct ft. lb./in. 1031 1.27 1.28 1.26 Unnotched Izod Impact ft/lb/in 4,3 4.2 5.0 4.9 DTUL at 264 psi, F 319 335 303 319 , 1) segmented copolyester-ether (duPont) 2) intrinsic viscosity of 0.62 measured in a 60/40 solution of phenol and tetrachloroethane.
The resistance to warpage of the above compositions is excellent.
Examples 10 - 12 The following formulations are mechanically blended then extruded and molded into test pieces in Van Dorn injection molding machine. The properties are summarized in the table below:
Table 3 ~xample _ 11 12_ Ingredients (parts by weight) Y~I,OX 300 41.8 31.8 36.8 fibrous glass reinforcement 11.0 11.0 11.0 c~-~fJ~l4 Table 3 cont'd Suæorite mica 200 S 25.0 25.0 25.0 poly(ethylene terephthalate)* . 20.0 20.0 20.0 Alathon 3194 - 10.0 Alathon 3152 - - 7.0 Microthene FN-510 2.0 2.0 Irganox 1093 0.15 0.15 0.15 Ferro 904 0.05 0.05 0.05 Properties Warpage R.T. ~ 1.5 3 2 Warpage 350 ~/30 min (mm) 9 2.5 8 Warpage 300 F/30 min (mm) 1.5 2.5 4.8 Notched Izod Impact, ft/lb/in 0.80 0.96 0.92 Unnotched Izod Impact ft/lb/in 6.6 7 5 7.1 DTUL at 264 psi, F 368 352 382 (1) ethylene-vinyl acetate copolymer (25% vinyl acetate, duPont) (2) ethylene-vinyl acetate copolymer (15% vinyl acetate, duPont) (3) polyethylene, average particle size less than 20 microns, sold by U.S.I. Chemicals, New York, New York.
*(intrinsic viscosity same as Table 2) Examples 13-16 The following formulations are mechanically blended then extruded and molded into test pieces in a Van Dorn injection molding machine. The properties are su7nmarized in Table 4.
Table 4 Example _ 14 15 16_ Ingredients ~-parts by weight) ~7ALCX 300 16.8 19.8 13.8 13.8 -- 1'1 --~ 8 CH-2654 Table 4 cont'd Fibrous glass reinforcement 11.0 11.0 11.0 11.0 Suzorite mica 200 S 25.0 25.0 25.0 --Suzorite mica 150 S -- -- -- 25.0 polyethylene (terephthalate)* 20.0 20.0 20.0 20.0 ALATHON 3194 7.0 7.0 7.0 7.0 Polyethylene 2.0 2.0 2.0 2.0 RL-1624 (G.E.) 13.0 10.0 16.0 15.0 Antimony oxide 5.0 5.0 5.0 6.0 Irganox 1093 0.15 0.15 0.15 0.15 Ferro 904 0.05 0~05 0.05 0-05 Properties Warpage, R.T. 0 0 0 0 Warpage, 350 F/30 min. (mm) 11 8.5 8 <1 Warpage, 300 F/30 min. (mm) 4 7 4 <1 Notched Izod Impact ft.lb/in. 0.89 0.890.9 1.0 Unnotched Izod Impact ft.lb/in. 6.4 6.6 6.2 5.9 DTUL at 264 psi, F 324 324 324 323 ~L Standard 94 94V-O 94V-O 94V-O 94V-O

(1) Flame-retardant, aromatic (copoly-)carbonate 50:50 mole ratio of bisphenol A and tetrabromobisphenol A.
*(intrinsic viscosity same as Table 2.) Example 17 The following formulation was mechanically blended, extruded and molded into test pieces in a Van Dorn injection molding machine. The composition and properties are summarized below:

~ 8 CH-2654 Example 17 contld Ingredient 17 18 (parts by weight) Valox 300 34.8 fibrous glass reinforcement 11.0 Suzorite mica 150S 25.0 poly(ethylene terephthalate) 20.5 Alathon 3194 7.0 polyethylene 2.0 Ferro 904 (antioxidant) 0.05 Irganox 1093 (antioxidant) 0.15 Properties Warpage R.T. (mm) 0 0 Warpage 350 F/30 min (mm) ~1 ~7 Warpage 300 F/30 min (mm) <1 Notched Izod Impact ft. lbs./in 1.0 1.26 DTUL at 264 psi, F 360 316 Example 18 The following ~ormulation was mechanically blended, extruded and molded into test pieces in a Van Dorn injection molding machine. The composition and properties are summarized below: -Ingredient 18 (parts by weight) block copolyester of poly(l,4-butylene terephthalat~) and poly(l,6-hexylene-(0.7) axelate-(0.3~ isophthalate molecular weight of block 300 34.8 fibrous glass reinforcement 11.0 Suzorite mica 150 S 25.0 poly(ethylene terephthalate) 20.0 Alathon 3194 7.0 8 CH-2~54 Example 18 cont'd polyethylene 2.0 Ferro 904 ~antioxidant) 0.05 Irganox 1093 (antioxidant) 0.15 Properties Warpage R.T. (mm) 0 Warpage 350 F/30 min (mm) 7 Warpage 300 F/30 min (mm) <~

Notched Izod Impact ft. lbs./in. 1.26 DTUL at 264 psi, F. 316 Obviously, other modifications and variations of the present invention are possible in light of the above teachings. For example, small amounts of materials such as dyes, pigments, stabilizers, plasticizers and the like can be added to the present compositions. It is to be understood, therefore, that changes may be made in the particular embodiments of the invention described which are within the full intended scope of the invention as defined by the appended claims.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An improved thermoplastic molding composition comprising, in intimate admixture.
(a) a thermoplastic resin selected from the group consisting of a high molecular weight linear polyester, a mixture of high molecular weight linear polyesters, a mixture of a high molecular weight linear polyester and high molecular weight block copolyester and mixtures of high molecular weight linear polyesters and high molecular weight block copolyester, wherein said block copolyester is derived from blocks of (i) a terminally-reactive poly(1-4-butylene terephthalate) and (ii) a terminally-reactive aromatic/aliphatic copolyester of a dicarboxylic acid selected from the group consisting of terephthalic acid, isophthalic acid, naphthalene dicarboxylic acids, phenyl indane dicarboxylic acid and compounds of the formula:
in which X may be alkylene or alkylidene of from 1 to 4 carbon atoms, carbonyl, sulfonyl, oxygen or a bond between the benzene rings, and an aliphatic dicarboxylic acid having from 2 to 12 carbon atoms in the chain and one or more straight or branched chain dihydric aliphatic glycols having from 2 to 10 carbon atoms in the chain, said copolyester having at least 10% of aliphatic units being derived from a dicarboxylic acid, or (iii) a terminally-reactive aliphatic polyester of a straight chain aliphatic dicarboxylic acid having from 4 to 12 carbon atoms in the chain and a straight or branched chain aliphatic glycol, said blocks being connected by inter-terminal linkages consisting essentially of ester linkages;
(b) fibrous glass reinforcement;
(c) phlogopite mica; and (d) an impact modifier

2. A composition as defined in Claim 1, wherein said thermoplastic resin is selected from the group consisting of a high molecular weight linear polyester and a mixture of high molecular weight linear polyesters.

3. A composition as defined in Claim 1, wherein said phlogopite mica has a particle size of from about 10 to about 325 mesh.

4. A composition as defined in Claim 1, wherein said impact modifier is selected from the group consisting of a segmented copolyester-ether, a silicone-polycarbonate block copolymer, an ethylene-vinyl acetate copolymer, a mixture of a segmented copolyester-ether and polyethylene, a mixture of a silicone polycarbonate block copolymer and polyethylene, and a mixture of an ethylene-vinyl acetate copolymer and polyethylene.

5. A composition as defined in Claim l wherein said glass reinforcement and said phlogopite mica are present in a combined amount of from about 1 to about 40%
by weight of the total composition and said impact modifier is employed in an amount within the range of from about 1%
to about 20% by weight of the total composition.

6. A composition as defined in Claim 1 which further includes a flame-retarding amount of a flame-retardant.

7. A composition as defined in Claim 1, wherein said thermoplastic resin is a high molecular weight linear polyester.

8. An improved thermoplastic molding composition comprising, in intimate admixture:
(a) a poly(1,4-butylene terephthalate) resin;
(b) fibrous glass reinforcement;
(c) phlogopite mica;
(d) an impact modifier; and (e) a flame-retarding amount of a flame-retardant.

9. An improved thermoplastic molding composition comprising, in intimate admixture;
(a) a poly(1,4-butylene terephthalate) resin;
(b) a poly(ethylene terephthalate) resin;
(c) fibrous glass reinforcement;
(d) phlogopite mica;
(e) an impact modifier; and (f) a flame retarding amount of a flame-retardant.

10. A composition as claimed in Claim 8, wherein said impact modifier is selected from the group consisting of a segmented copolyester-ether, a silicone-polycarbonate block copolymer, an ethylene-vinyl acetate copolymer, a mixture of a segmented copolyester-ether and polyethylene, a mixture of a silicone-polycarbonate block copolymer and polyethylene and a mixture of an ethylene-vinyl acetate copolymer and polyethylene.

11. A composition as defined in Claim 8, wherein said phlogopite mica has a particle size of from about 10 to about 325 mesh.

12. A composition as defined in Claim 9, wherein said impact modifier is selected from the group consisting of a segmented copolyester-ether, a silicone-polycarbonate block copolymer, an ethylene-vinyl acetate copolymer, a mixture of a segmented copolyester-ether and polyethylene, a mixture of a silicone-polycarbonate block copolymer and polyethylene and a mixture of an ethylene-vinyl acetate copolymer and polyethylene

13. A composition as defined in Claim 9, wherein said phlogopite mica has a particle size of from about 10 to about 325 mesh.

14. A compostion as defined in Claim 8, wherein said impact modifier is an ethylene-vinyl acetate copolymer.

15. A composition as defined in Claim 8, wherein said impact modifier is a mixture of an ethylene-vinyl acetate copolymer and polyethylene.

16. A composition as defined in Claim 9, wherein said impact modifier is an ethylene-vinyl acetate copolymer.

17. A composition as defined in Claim 9, wherein said impact modifier is a mixture of an ethylene-vinyl acetate copolymer and polyethylene.