JPS5912960A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic resin composition having remarkably improved impact strength and weatherability, by compounding a polycarbonate with a specific polyester block copolymer. CONSTITUTION:The objective resin composition is prepared by compounding (A) 2-97wt% of a polycarbonate with (B) 3-98wt%, preferably 3-90wt% of a polyester block copolymer obtained by reacting a crystalline aromatic polyester with a lactone at a weight ratio of 80/20-20/80. The component (A) is preferably the one containing bisphenol A as the dihydroxy component and having an average molecular weight of 10,000-40,000, and the component (B) is preferably the one having polylactone content of 30-80wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin composition having excellent impact resistance and weather resistance.

Polycarbonate has excellent impact strength and tensile strength.
Furthermore, it has excellent creep properties, high-temperature properties, low-temperature properties, and electrical properties, and is used in a wide range of applications.

However, when polycarbonate is used alone as an exterior material such as car bumpers and car door handles,
It has been pointed out that it has poor weather resistance. Furthermore, the impact resistance is not fully satisfactory at extremely low temperatures of -jO<0>C.

Furthermore, it has been proposed to improve the impact brittle rupture properties and low-temperature impact resistance of polycarbonate resin by blending polyester ether elastomer with polycarbonate (Japanese Unexamined Patent Publication No. 54651/1983).
However, even if 1 polyester ether elastomer is blended, no improvement in weather resistance is observed.

The inventors of the present invention conducted various intensive studies for the purpose of improving the impact resistance and weather resistance of polycarbonate, and as a result discovered that 1. a polyester block copolymer obtained from a crystalline aromatic polyester and lactones could be blended; invention has been achieved.

That is, the present invention comprises polycarbonate (1) 2 to 97% by weight, crystalline aromatic polyester (A), and lactones (
B) in weight ratio (A)/(B) = ao7'go~2
It is a thermoplastic resin composition consisting of 3 to 98% by weight of a polyester block copolymer (■) obtained by reacting a 0/80 IJIJ reaction.

In the present invention, polyester is applied to polycarbonate. Furthermore, weather resistance has been significantly improved2).

The reaction product of polycarbonate with crystalline aromatic polyester glycol and lactones is randomized and the melting point is lowered, so even if blended with polycarbonate, the impact resistance is improved, but the chemical resistance is poor. Furthermore, when a polyester polyether block copolymer is blended with polycarbonate, although the impact resistance is improved, the elongation resistance is not fully satisfied.

Examples of the polycarbonate used in the present invention include polycarbonates having repeated coagulation represented by the general formula (1) obtained by the reaction of diphenyl carbonate glycol or bispheno-Il/s or the reaction of glyfur or bisphenols with phosgene. .

(-0-R-0-'O+ (1) (In the formula, R represents a divalent organic group.) Examples of glycols that can be used as starting materials for polycarbonate include tetramethylene glycol, hexamethylene glycol, and decamethylene glycol. 1bis(4-hydroxyphenyl)sulfone 1bis(3-ri4-hydroxyphenyl)sulfone, bis(3,5-dibromo-
4-hydroxyphenyl)sulfone, (2-hydroxyphenyl)(4/-hydroxyphenyl)sulphone, 4
．． 4'-dihydroxydiphenyl ether, 4. ,,4
Examples include '-dihydroxy-313'-dichlorodiphenyl ether. Examples of bisphenols include bis(4-hydroxyphenyl)methane, 1. l-bis(4-hydroxyphenyl)ethane,
1.1-Bis(4-hydroxyphenyl)butane, bis(4-hydroxyphenyl)cyclohexane SQ@E!
-bis(4-hydroxyphenyl)propane, 2,2-
Examples include bis(3-chlorokyl-4-human p-xyphenyl)propane and 2,2-bis(3,s-dibromo-4-hydroxyphenyl)propane.

The polycarbonate used in the present invention is preferably a 4°4'-dihydroxydiallylalkane polycarbonate, particularly a polycarbonate containing bisphenol A as a diochira component. The average molecular weight of the polycarbonate is 10
,000~40. OOO is preferred.

The polyester block copolymer used in the present invention is obtained by reacting a crystalline aromatic polyester with lactones.

In the present invention, the term "crystalline aromatic polyester" refers to a polymer mainly composed of ester bonds or ester bonds and ether bonds, and therefore has at least one type of aromatic group as a main repeating unit, and has a hydroxyl group at the end of the molecule. As a molding material, the molecular weight is preferably 500.
It is 0 or more. Preferred specific examples include 1 polyethylene terephthalate 1 polytetramethylene terephthalate, poly-1,4-cyclohexylene dimethyl tere 7
Homopolyesters such as polyethylene-2,6-naphthalate, polyester ethers such as polyethyleneoxybenzoate, poly-p-phenylenebisoxyethoxytere-7thaleate, mainly consisting of tetramethylene phthalate units or ethylene phthalate units, and other A copolymerized polyester or a copolymerized polyester ether having a copolymer component such as one methylene or ethylene isophthalate unit, one tetramethylene or ethylene adipate unit, and one tetramethetramethylene or ethylene-p-oxybenzoate unit. .

As the lactone, ε-caprolactone is most preferred, and enantolactone, cabri-tetralactone and the like can also be used. Two or more kinds of lactones can also be used at the same time.

In order to obtain the polyester type block copolymer used in the present invention, 1) When reacting the crystalline polyester with lactones, 1 may be carried out without a catalyst, or with a catalyst.

The polylactone content in the polyester block copolymer used in the present invention is preferably 20 to 80% by weight, particularly preferably 30 to 80% by weight. When the content of the crystalline aromatic polyester exceeds 80% by weight, the Izot impact strength of the composition is small and the effect as an impact modifier is small.

Polymerization of polyester block copolymer K Get A reduced specific viscosity in the range of 0.5 to 4.0 measured at 3°C and a concentration of 5osv/25- in phenol/tetrachloroethane = 6/4 weight ratio. Preferably, 0.7 to 3.
0 is preferred.

The resin composition of the present invention comprises the above-mentioned polycarbonate [l]
and a polyester block copolymer (It) can be easily obtained by melt-mixing the polyester block copolymer (It).It is possible to significantly improve the impact resistance and weather resistance and the impact resistance at low temperatures, which are the objectives of the present invention. O polycarbonate and polyester block copolymer,
The mixing ratio of the polyester block copolymer is 3 to 98% by weight, preferably 3 to 90% by weight of the total composition. Impact strength and weather resistance do not improve. Moreover, if the weight of the copolymer exceeds 98 weight, molding shrinkage becomes large, which is not preferable.

In the present invention, as described above, polycarbonate and polyester block copolymer are melt-mixed in a specific ratio. As the mixing method, for example, a method of melt-mixing using an extruder, a method of mixing each chip of polycarbonate and polyester block copolymer and melt-molding, a method of melt-mixing in a tank, etc. can be used. The resin composition may contain various additives such as stabilizers, pigments, flame retardants, crystallization promoters, reinforcing agents (for example, glass fiber), fillers, mold release agents, etc., all of which do not impair the purpose of the present invention. It may be contained within the range. If necessary, other resins such as PBT may also be used.

ABS, Surlyn A, PP, etc. may be blended.

The resin composition of the present invention has extremely excellent impact resistance at room temperature and low temperature, and is also excellent in weather resistance. Therefore, applications 11 that require extremely excellent impact resistance, such as automobile bumpers 1 and helmets, etc. It is useful as a material for

The present invention will be explained in detail below with reference to examples, but the present invention is not limited by these examples. In the examples, "part" means part by weight.

Example 1 Polycarbonate [I]: Valalyte L-1250 (trade name of Yatai Kasei ■) Polyester block copolymer (I
t): 50 parts of polybutylene terephthalate and 50 parts of 6-caprolactone were placed in a reaction vessel, and after purging with nitrogen gas, the mixture was stirred at 230°C and melted for 2 hours, followed by a melt reaction.
Unreacted ε-caprolactone was removed under vacuum. The obtained Borie 7-liter block copolymer has a reduced specific viscosity of 1.
It was 163.

The above-mentioned resins [1] and [■] were mixed at the mixing ratio shown in Table 1 using a melt extruder with a set of screws having a diameter of 30 fins to form pellets 7). Next, screw type injection molding machine (
3.5 oz) at a temperature of lf3240°C.

The impact strength of the resulting molded products (having the thickness shown in Table 1) was measured by the method of Notch+I'AsTMD256.

Note that 1 measurement was carried out at room temperature and -50°C, and the obtained results are shown in Table 1.

From the results in Table 1, the brittle fracture phenomenon observed at room temperature in inch-sized polycarbonate resin molded products is significantly improved when the polyester block copolymer is contained at 3% by weight, and brittle when the polyester block copolymer is contained at 5% by weight or more. It can be seen that no destructive phenomenon is observed at all. It is also seen that the low-temperature impact strength at -50°C is significantly improved by mixing the polyester block copolymer.

Izot @ impact strength (with notch) (y4 inch) after irradiating sample-3 for 1000 hours with fade meter is 38
kg-cvg/cI@.

Comparative Example 1 93.4 parts of dimethyl terephthalate, 60 parts of 1.4-butanediol, 47.3 parts of bo(υN tetramethylene oxide) glycol with an average molecular weight of 1075, 0.06 part of tetra-n-butyl titanate, 1 sumilizer (oxidized 0.3 parts of inhibitor (manufactured by Sumima Kagaku Co., Ltd.) was charged into a stainless steel reaction vessel, and the transesterification reaction was completed at 5140 to 230°C for 60 minutes. Next, the internal temperature of the reaction system was raised from 230°C to 240°C over 90 minutes, and the pressure was gradually reduced from normal pressure to below l tnrnHg.
Furthermore, polymerization was continued for 90 minutes under these conditions. Obtained Polyester Polyether Block Copolymer When 30 parts of this polyester polyether block copolymer was mixed with 70 parts of the same polycarbonate as in Example 1, Izot impact strength (notched) at room temperature (25°C) (%) Inch) is 52kg II C1l/e1m, and after 1000 hours of irradiation, the same Izotsu) & Nottsuchiki (Simi inch) is 12kg・C11l
/cm.

Comparative Example 2 The Izo impact strength (with notches) (S/4 inch) at room temperature of a molded product made from a composition in which 70 parts of polycarbonate and 30 parts of polytetramethylene terephthalate were molded in the same manner as in Example 1 was 1 l kg m cm/c
Comparative Example 3 Izo impact strength (with notches) at room temperature ('A inch) of a molded product made from a composition in which 70 parts of polycarbonate and 30 parts of polycaprolactone were mixed in the same manner as in Example 1 was l Okg・Cl1150 Patent applicant: Toyobo Co., Ltd. Kinsha

Claims (1)

[Claims] 2 to 97% by weight of polycarbonate (+), crystalline aromatic polyester (A) and lactones (B) in a weight ratio of (A)
)/(B): 80/20 to 20/130 ry) A thermoplastic resin composition consisting of a polyester block copolymer [■] 3 to 98% by weight.