JPH0873717A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE: To obtain a polybutylene terephthalate resin alloy improved in surface appearance and reduced in warpage. CONSTITUTION: 100 pts.wt. blend of 40-80wt.% polybutylene terephthalate resin and 20-60wt.% aromatic polycarbonate resin is mixed with 5-30 pts.wt. polyethylene terephthalate resin and 5-50 pts.wt. filler to give a thermoplastic resin composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition, and more particularly to a thermoplastic resin composition excellent in surface appearance, low warpage, rigidity and heat resistance.

[0002]

2. Description of the Related Art Polybutylene terephthalate resin is a thermoplastic resin material having various excellent properties such as oxidation resistance and solvent resistance, and is a molded product having good physical and mechanical properties by injection molding. Can be obtained.
However, since the polybutylene terephthalate resin has high crystallinity, warpage is likely to occur in the molded product, and the dimensional stability is poor.

Polycarbonate resins have an excellent balance of physical properties and dimensional stability and are used in a wide range of fields. However, their chemical resistance and solvent resistance are insufficient, so that these properties are improved. Is required.

A blend of a polybutylene terephthalate resin and a polycarbonate resin is presumed to be suitable for the purpose of improving the dimensional stability of the polybutylene terephthalate resin and improving the chemical resistance and solvent resistance of the polycarbonate resin.

However, when a filler is blended for the purpose of imparting rigidity and heat resistance, the molded product has a drawback that the surface appearance is inferior, and it is difficult to apply it to applications where surface appearance is required. there were. Therefore, as a result of intensive studies to obtain a resin composition having a good surface appearance, the present invention has been achieved.

[0006]

OBJECT OF THE INVENTION It is an object of the present invention to provide a resin composition which is excellent in surface appearance, low warpage, rigidity and heat resistance.

[0007]

The present invention comprises (A) polybutylene terephthalate resin 40 to 80% by weight and (B) aromatic polycarbonate resin 20 to 60% by weight (A).
+ (B) 100 parts by weight of the blend, (C) polyethylene terephthalate resin 5 to 30 parts by weight and (D) filler 5 to 50 parts by weight of a thermoplastic resin composition (total 100 parts by weight) Section).

The polybutylene terephthalate resin as the component (A) used in the present invention is obtained by substantially polycondensing terephthalic acid or a terephthalic acid derivative and tetramethylene glycol. As an acid component, part of terephthalic acid is replaced with isophthalic acid, naphthalene dicarboxylic acid, adipic acid or sebacic acid, and part of the alcohol component, tetramethylene glycol, is replaced with ethylene glycol, propylene glycol, or oxybenzoic acid. Are used as a copolymerization component in a small amount.

The aromatic polycarbonate resin as the component (B) used in the present invention is, for example, 4,4'-dihydroxyphenylalkane-based polycarbonate,
More specifically, 2,2- (4,4'-dihydroxydiphenyl) propane (hereinafter abbreviated as bisphenol A)
Polycarbonate obtained by the transesterification method or the phosgene method using is used as the dihydroxy component.
Furthermore, some or all of bisphenol A can be replaced with other 4,4 '
-Dihydroxydiphenylalkane or 4,4'-dihydroxydiphenylether may be substituted, or two or more kinds of aromatic polycarbonates may be mixed and used.

The aromatic polycarbonate has a number average molecular weight of 10,000 to 100,000, preferably 180.
00-80,000, particularly preferably 20000-500
The range is 00.

When the composition contains less than 40% by weight of the polybutylene terephthalate resin in the blend (A) + (B), the heat resistance of the polybutylene terephthalate resin is impaired when used in combination with the below-mentioned filler, and 80% by weight. If it exceeds, it becomes difficult to develop low warpage, which is not preferable.

On the other hand, when the polycarbonate resin component is less than 20% by weight, it is difficult to exhibit a low warp property, and when it exceeds 60% by weight, the heat resistance is insufficient.

The component (C) polyethylene terephthalate resin used in the present invention is a polyethylene terephthalate resin obtained by using terephthalic acid or its ester-forming derivative as the acid component and ethylene glycol or its ester-forming derivative as the glycol component. However, it is also possible to replace a part of the terephthalic acid component and / or the ethylene glycol component with a copolymerization component. Examples of the copolymerization component include isophthalic acid, phthalic acid; halogen-substituted phthalic acids such as tetrabromophthalic acid and tetrabromoterephthalic acid; 2,6-
Naphthalenedicarboxylic acids such as naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, and 1,5-naphthalenedicarboxylic acid; diphenyldicarboxylic acids such as 4,4′-diphenylcarboxylic acid and 3,4′-diphenyldicarboxylic acid; Aromatic dicarboxylic acids such as 4,4′-diphenoxyethanedicarboxylic acid; Aliphatic or alicyclic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid, decadicarboxylic acid, cyclohexanedicarboxylic acid; trimethylene Aliphatic or alicyclic diols such as glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol; dihydroxybenzenes such as hydroquinone and resorcin; 2,2′-bis ( Hide Roxyphenyl) propane,
Bisphenols such as 2,2′-bis (4-hydroxyphenyl) -sulfone; Aromatic diols such as ether diols obtained from bisphenols and glycols such as ethylene glycol; Polyoxyethylene glycol, polyoxypropylene Examples thereof include polyoxyalkylene glycols such as glycol and polyoxytetramethylene glycol, and oxycarboxylic acids such as ε-oxycaproic acid and hydroxybenzoic acid.

These copolymerization components may be used alone or in combination of two or more, and the proportion thereof is not more than 20 mol% based on the total dicarboxylic acid (oxycarboxylic acid (half amount of oxycarboxylic acid is calculated as carboxylic acid)). It is particularly preferably 10 mol% or less.

Further, the above-mentioned polyethylene terephthalate resin is a branched component, for example, a trifunctional acid such as tricarballylic acid, trimellitic acid and trimellitic acid, or a tetrafunctional acid such as pyromellitic acid, or glycerin, Proportion of 1.0 mol% or less, preferably 0.5 mol% or less, and more preferably 0.3 mol% or less of alcohol having a trifunctional or tetrafunctional ester forming ability such as trimethylolpropane and pentaerythritol. It may be copolymerized with.

Component (C) in 100 parts by weight of the total composition
The mixing ratio of the polyethylene terephthalate resin is 5 to 3
It is 0 parts by weight, preferably 10 to 20 parts by weight.
If the amount of the polyethylene terephthalate resin is less than 5 parts by weight, there is no effect of improving the surface appearance, and if it exceeds 30 parts by weight, the crystallization rate of the polyethylene terephthalate resin becomes slow, resulting in defective molding, which is not preferable.

The component (D) filler used in the present invention is a fibrous material such as glass fiber, asbestos, carbon fiber, aromatic polyamide fiber, potassium titanate fiber, steel fiber, ceramics fiber, boron whisker fiber and the like. Examples thereof include powdery, granular or plate-like inorganic fillers such as mica, silica, talc, calcium carbonate, glass beads, glass flakes, clay and wollastonite. These fillers are usually blended for the purpose of modifying the reinforcing material, thermal characteristics and the like, and among these fillers, glass fiber is particularly preferable. The glass fiber is not particularly limited as long as it is generally used for reinforcing a resin. For example, long fiber type (glass roving), short fiber chopped strand, milled fiber or the like can be selected and used. The glass fiber may be treated with a sizing agent (for example, polyvinyl acetate, epoxy, urethane, etc.), a coupling agent (for example, a silane compound, a borane compound, etc.), and other surface treatment agents. Note that long-fiber type glass fibers are usually used after being cut with a desired length after blending with a resin, but this mode of use is also useful in the present invention.

The blending ratio of the filler to the total composition is 5 to 5.
It is 50 parts by weight, preferably 10 to 40 parts by weight. When the amount of the filler is less than 5 parts by weight, the reinforcing effect due to the blending of the filler is poor, and when it exceeds 50 parts by weight, the melt fluidity of the composition is remarkably deteriorated, so that a molded product having a good appearance can be obtained. Absent.

Various additives can be added to the resin composition of the present invention to the extent that the object of the present invention is not impaired. Examples of the additives include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, ultraviolet absorbers, release agents, flame retardants, inorganic fillers, coloring agents and the like.

As these additives, those generally known as additives for resins can be used according to the purpose.

The phenolic antioxidant is generally a hindered phenolic compound added to improve the heat resistance of the resin. For example, 2,6-di-t-butyl-p
-Cresol, 2,2'-methylene-bis (4-methyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-butylphenol), 1,1,
3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl- 3- (3,
5-di-t-butyl-4-hydroxyphenyl) propionate and the like can be mentioned.

As the phosphorus antioxidant, triphenyl phosphite, trioctadecyl phosphite,
Trisnonylphenyl phosphite, trilauryl trithiophosphite, bis (2,4-di-t-butylphenyl) pentaerythritol-diphosphite,
Bis (3-methyl-1,5-di-t-butylphenyl)
Pentaerythritol-diphosphite, tris (2,4-di-t-butylphenyl) phosphite,
Inorganic phosphates such as sodium dihydrogen phosphate dihydrate are included.

The method of preparing the thermoplastic resin composition of the present invention is carried out by melt-mixing by a known method of mixing solid substances (for example, mixing means such as Banbury mixer, heating roll, single-screw or multi-screw extruder). After that, it can be molded.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

All "%" in the examples are based on weight (wt%), and the intrinsic viscosity numbers of polybutylene terephthalate and polyethylene terephthalate described in the examples were measured at 35 ° C. using orthochlorophenol as a solvent. It is a value.

The bending strength and flexural modulus are ASTM-79.
0, deflection temperature under load is ASTM-648, impact strength is AS
TM-256, the surface appearance of the molded product is JISK7105
Measured by 60 degree specular gloss.

The warp is 200 mm long and 130 m wide.
m, height 50 mm, box-shaped product with a thickness of 3 mm,
The box sled was measured.

[0028]

【Example】

[Examples 1 to 3 and Comparative Examples 1 to 3] Polybutylene terephthalate (intrinsic viscosity number 0.7) dried at 130 ° C for 5 hours.
1), polyethylene terephthalate (intrinsic viscosity number 0.7
1), Panlite L-1 as an aromatic polycarbonate
Various resin compositions were prepared by uniformly mixing 225 (trade name; manufactured by Teijin Chemicals Ltd.) with glass chopped strands having a length of 3 mm at a ratio shown in Table 1 using a V-type blender.
The obtained composition was melt-kneaded with a twin-screw extruder having a diameter of 44 mm at a barrel temperature of 260 ° C., and the thread discharged from the die was cooled and cut to obtain molding pellets. Then, after drying these pellets with hot air at 120 ° C. for 5 hours, 8.
Attach the test piece mold to a 3 ounce injection molding machine,
Cylinder temperature 260 ℃, mold temperature 60 ℃, injection pressure 7
00 kg / cm ² , cooling time 20 seconds and total cycle 35
The test piece was molded under the molding condition for 2 seconds.

The characteristics of these test pieces were evaluated and the results are shown in Table 1.

[0030]

[Table 1]

From Table 1, as shown in the present invention, when polyethylene terephthalate (hereinafter referred to as PET) is not blended, the surface appearance indicated by gloss is inferior, and when polycarbonate (hereinafter referred to as PC) is not blended. The amount of polybutylene terephthalate (hereinafter referred to as PB
If it is not compounded (denoted as T), the deflection temperature under load is inferior. It has been found that a well-balanced resin composition can be obtained by the combination of these.

[Examples 4 to 7 and Comparative Examples 4 to 6] Table 2 shows the results of evaluation of the compounding effect of each component in the same manner as in Example 1.

[0033]

[Table 2]

As shown in Table 2, when the compounding amount of PC is small and the compounding amount of PBT is large, the warp amount is large, and the PC amount is large.
When the blending amount of PBT is large and the blending amount of PBT is small, the gloss is lowered and the deflection temperature under load is low. On the other hand, if the amount of PET added is too large, the deflection temperature under load decreases, which is not preferable. Therefore, it was found that the compounding of a specific ratio is necessary in order to obtain a composition having a high gloss and a deflection temperature under load and less warping.

Claims (1)

[Claims] 1. A polybutylene terephthalate resin (A).
(C) 5 to 30 parts by weight of (C) polyethylene terephthalate resin and (D) to 100 parts by weight of a blend of (A) + (B) consisting of 40 to 80% by weight and (B) 20 to 60% by weight of aromatic polycarbonate resin. ) A thermoplastic resin composition containing 5 to 50 parts by weight of a filler.