GB2040973A

GB2040973A - Polyester-polyarylene Ester Compositions

Info

Publication number: GB2040973A
Application number: GB8001735A
Authority: GB
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1979-01-30
Filing date: 1980-01-18
Publication date: 1980-09-03
Also published as: FR2447949B1; DE3002814A1; BR8000593A; AU534147B2; NL8000541A; JPS55115444A; GB2040973B; FR2447949A1; AU5473280A

Abstract

Thermoplastic molding compositions are disclosed which comprise poly(1,4-butylene terephthalate), and a polyarylene ester resin, alone, or combined with a poly(ethylene terephthalate) alone, or in further combination with reinforcing agent.

Description

SPECIFICATION Polyester-polyarylene Ester Compositions This invention provides a noval thermoplastic molding composition which comprises poly( 1,4- butylene terephthalate), and a polyarylene ester resin, alone, or in combination with poly-(ethylene terephthalate) and/or a reinforcing amount of a reinforcing filler.

Poly(1 ,4-butylene terephthalate) resins are well known and have been widely employed for the production of thermoplastic molded articles. Also, reinforced compositions of poly( 1 ,4-butylene terephthalate) have been commercially available for a number of years. These compositions are useful for a plurality of applications especially when a high degree of solvent resistance is required. Glass fiber reinforced poly(1 ,4-butylene terephthalate) when molded into various articles has a tendency to become distorted or warped especially when the molded article has a thin section.

It has been found that if a polyarylene ester resin or mixture thereof with a poly(ethylene terephthalate) resin is added to the reinforced poly(1 ,4-butylene terephthalate) molding composition, the molded articles are substantially resistant to warpage or distortion after they are removed from the mold. In unreinforced modifications, there is no reduction in heat deflection temperature under load.

These results are achieved without any appreciable decrease in the mechanical, physical or molding properties of a typical poly(1 ,4-butylene terephthalate) molding compositions, whether or not they contain reinforcing agents.

The present invention provides a novel thermoplastic molding composition which comprises: (a) poly(1 ,4-butylene terephthalate) and (b) a polyarylene ester resin, alone, or in combination with a minor proportion of poly(ethylene terephthalate).

A preferred embodiment will also include (c) a reinforcing amount of a reinforcing agent.

The poly( 1 ,4-butylene terephthalate) should have an intrinsic viscosity between 0.4 and 1.2 dl/g.

as measured at 300 C. in a 60/40 solution of phenol/tetrachloroethane. A more preferred range is between 0.6 and 0.9 dl/g.

The polyarylene ester resin typically has recurring units of the formula:

i.e., it comprises units derived from terephthalic acid and/or isophthalic acid, or reactive derivatives thereof, wherein each -R- is selected from the group consisting of phenylene, halo-substituted phenylene and alkyl substituted phenylene, and X and Y are each selected from the group consisting of hydrogen, hydrocarbon radicals free from aliphatic unsaturation and of radicals which together with the adjoining -C- atom form a cycloalkane radical, the total number of carbon atoms in X and Y being up to 12.

The preferred polyarylene ester resins may be derived from the reaction of bisphenol-A and isophthalic acid, terephthalic acid, mixtures thereof or reactive derivatives thereof, such as isophthaloyl chloride, dimethyl isophthalate terephthaloyl chloride, dimethyl terephthalate and the like. These preferably will have recurring units of the formula:

The polyarylene ester resins can be prepared by those skilled in this art using conventional techniques. They should have an intrinsic viscosity between 0.3 and 1.0, preferably from 0.3 to 0.45 as measured at 200C. in methylene chloride. See U.S. 3,792,118, which is incorporated herein by reference. They can include from 1 to 50 wt.% of blended poly(ethylene terephthalate).

The reinforcing agents in the optical embodiments may be selected from finely divided aluminum, iron or nickel and the like, and non-metals, such as carbon filaments, silicates, such as acicular calcium silicate, asbestos, titanium dioxide, wollastonite, potassium titanate and titanate whiskers, glass flakes and fibers.

Although it is only necessary to use a reinforcing amount of the reinforcing agent, from 1-60 parts by weight of the total weight of the composition may comprise the reinforcing agent. A preferred range is from 5-40 parts by weight. When used herein, parts by weight are based on 100 parts by weight in total composition.

The preferred reinforcing agents are of glass, and it is preferred to use fibrous glass filaments. The preferred filaments tor plastics reinforcement are made by mechanical pulling. The filament diameters range from about 0.000112 to about 0.00075 inch, but this is not critical to the present invention.

The poly-(1 ,4-butylene terephthalate) resin may comprise from 95 to 20 parts by weight of the composition and the polyarylene ester resin or blend with poly(ethylene terephthalate) may comprise from 5 to 80 parts by weight of the resinous components (a) and (b) in the composition.

The preferred compositions will include from 90 to 65 parts by weight of poly(1 ,4-butylene terephthalate) and from 10 to 35 parts by weight of the polyarylene ester resin or resin blend.

The composition may be prepared by any standard procedure and the particular method employed is not critical.

The compositions may also include flame retardants such as those disclosed in U.S. 3,915,926, which is incorporated herein by reference.

The following examples illustrate compositions within the scope of this invention. They are not to be construed as limiting the claims thereto. In the data tables, "N.D. means-not determined.

Example 1 The following compositions are prepared by blending the materials in an extruder: Example Composition (parts by weight) I 1A (control) poly(1,4-butylene terephthalate)* 55 70 poly(4,4'-diphenylene propane/ tereisophthalate) resin** 15 glass fibers 1/8" (Owens Corning OCF 419, 1/8") 30 30 stabilizer*** 0.05 0.05 * Intrinsic viscosity, 0.8 dl./g.

** Polyarylate U-Polymer, U-1 060, product of Unitika Company, Japan, ratio of iso/tere of 30/70, and includes about 4.5 wt.% of poly(ethylene terephthalate).

Ferro 904.

These compositions have the following physical properties after injection molding into test pieces: Properties 1 1A (control) Specific Gravity, g./cc. 1.512 1.542 Deflection temperature at 264 psi, OF. 344 396 Warpage, 1/1 6"x4" diameter disc, mm., as molded 0 20 mm.,after30min.at3500F. 17 25 Notched Izod impact. ft. Ibs./in. 1.9 1.8 Unnotched Izod impact, ft. Ibs./in. 17.1 14.5 Flexural strength, psi. 25,600 26,800 Flexural modulus, psi. 971,000 993,000 Tensile strength, psi. 16,400 18,000 Elongation at break, % N.D. N.D.

Example 2 The following composition is prepared by blending the materials in an extruder: Composition (parts by weight) poly(1 4-butylene terephthalate)* 40 poly(4,4'-diphenylenepropane tere/ 30 isophthalate) resin** glass fibers 1/8" (Owens Corning, OCF419, 1/8") 30 stabilizer*** 0.05 * Intrinsic viscosity, 0.8 dl./g.

** Polyarylate U-Polymer, U-1060, product of Unitika Company, Japan, see Example 1.

Ferro 904.

This composition has the following physical properties after injection molding: Properties Specific Gravity, g./cc. 1.483 Deflection temperature at 264 psi, OF. 160 Warpage, 1/1 6"x4" diameter disc, mm., as molded 0 mm., after 30 min. at 3500F. 19 Notched Izod impact ft. Ibs./in. 2.1 Unnotched Izod impact ft. Ibs./in. 15.3 Flexural strength, psi. 27,300 Flexural modulus, psi. 1,061,000 Tensile strength, psi. 17,200 Elongation at break, % N.D.

Example 3 The following unreinforced compositions are prepared by blending the materials in an extruder: Example Composition (parts by weight) 3 3A (control) poly(1,4-butylene terephthalate)* 80 100 poly(4,4'-diphenylenepropane tere/ isophthalate) resin** 20 stabilizer*** 0.05 0.05 * Intrinsic viscosity, 1.1 dl./g.

** Polyarylate U-Polymer, U-1 060, product of Unitika Company, Japan, see Example 1.

Ferro 904.

These compositions have the following physical properties after injection molding: Properties 3 3A (control) Specific Gravity, g./cc. 1.287 1.31 Deflection temperature at 264 psi, OF. 149 136 Warpage, 1/1 6"x4" diameter disc, mm., as molded 0 0 mm., after 30 min. at 35O0F. distorted 15 Notched Izod impact, ft. Ibs./in. 1.2 1.2 Unnotched Izod impact, ft. Ibslin. break break Flexural strength, psi. 12,500 12,600 Flexural modulus, psi. 334,000 351,000 Tensile strength, psi. 8,300 8,100 Elongation at break, % 135 307

Claims

1. A thermoplastic molding composition which comprises: (a) poly(1,4-butylene terephthalate); and (b) a polyarylene ester resin, alone, or in combination with a minor proportion of poly(ethylene terephthalate).

2. A composition as defined in Claim 1 which also includes: (c) a reinforcing amount of a reinforcing agent.

3. A thermoplastic molding composition as defined in Claim 1 wherein the polyarylene ester resin consists essentially of recurring units in the formula:

wherein each -R- is selected from the group consisting of phenylene, halo-substituted phenylene and alkyl substituted phenylene, and X and Y are each selected from the group consisting of hydrogen, hydrocarbon radicals free from aliphatic unsaturation and of radicals which together and with the adjoining -C I atom form a cycloalkane radical, the total number of carbon atoms in X and Y being up to 12.

4. A thermoplastic molding composition as defined in Claims 1-3 wherein the polyarylene ester resin has the repeating unit

5. A thermoplastic molding composition as defined in claims 2-4 which comprises: (a) from 95 to 20 parts by weight of poly (1 ,4-butylene terephthalate); (b) from 5 to 80 parts by weight of a poly (diarylenealkylene-co-tere/isophthalate) resin; (c) from 1 to 60 parts by weight of filamentous glass.

6. A thermoplastic molding composition as defined in Claims 1-5 which includes a flameretardant amount of a flame-retardant agent.

7. A method of preventing distortion in a thermo-plastic molded article which is formed of a thermoplastic composition that comprises a poly(1,4-butylene terephthalate) resin and a reinforcing agent said method comprising including in said thermoplastic composition a polyarylene ester resin alone or combined with poly(ethylene terephthalate) as defined in Claim 1 in an amount sufficient to prevent distortion of the molded article.

8. A method as defined in Claim 7 wherein the polyarylene ester resin has recurring units of the formula:

wherein each -R- is selected from the group consisting of phenylene, halo-substituted phenylene and alkyl substituted phenylene, and X and Y are each selected from the group consisting of hydrogen, hydrocarbon radicals free from aliphatic unsaturation and of radicals which together with the adjoining atom form a cycloalkane radical, the total number of carbon atoms in X and Y being up to 12.

9. A method as claimed in Claim 7 and substantially as hereinbefore described with reference to any of the Example.

9. A method as defined in claim 8 wherein the polyarylene ester has the repeating unit

10. A method as defined in Claim 9 wherein the reinforcing agent is filamentous glass.

8. A thermoplastic moulding composition as claimed in Claim 1 and substantially as hereinbefore described with reference to any of the Examples.