JPH0672203B2 - Polyester resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyester resin composition which is excellent in corrugation processability and mechanical properties and is suitable for molded articles in the fields of automobiles, home appliances and the like.

[Prior Art] Polyethylene terephthalate resin has excellent heat resistance, rigidity, chemical resistance, etc., but poor moldability. On the other hand, the polybutylene terephthalate resin is superior in molding processability to the polyethylene terephthalate resin, but is poor in heat resistance. Therefore, as a resin that compensates for the drawbacks of the polyethylene terephthalate resin and the polybutylene terephthalate resin, a polyester resin composition obtained by mixing the polyethylene terephthalate resin and the polybutylene terephthalate resin is known (JP-A-48). −38
No. 343).

[Problems to be Solved by the Invention] However, if the polyethylene terephthalate resin and the polybutylene terephthalate resin are simply mixed, the moldability and the heat resistance are well balanced,
Moreover, a polyester resin composition having excellent mechanical properties cannot be obtained.

[Means for Solving Problems] The present invention has been made based on the above circumstances,
A polyester resin composition obtained by blending a polyethylene terephthalate resin and a polybutylene terephthalate resin in a ratio of characteristics, and a glass fiber in a specific ratio to the polyester resin, a polyester resin composition containing a talc and a polyalkylene glycol compound is molded. The present invention has been reached by finding that workability, heat resistance, mechanical properties and the like are simultaneously excellent.

That is, an object of the present invention is to provide a polyester resin composition having excellent mechanical properties, heat resistance and molding processability.

The outline of the present invention for achieving the above object is a polyester containing a polyethylene terephthalate resin (A) and a polybutylene terephthalate resin (B) and having a compounding ratio (A) / (B) of both of 0.2 to 2. Resin 100 parts by weight, glass fiber 5 to 65 parts by weight, talc 0.5 to 10 parts by weight, and polyalkylene glycol compound 0.5 to 5
And a polyester resin composition.

The polyethylene terephthalate resin (hereinafter abbreviated as PET) in the present invention is a linear polyester obtained by polycondensing terephthalic acid or dialkyl terephthalate and ethylene glycol, terephthalic acid or dialkyl terephthalate and ethylene glycol as main components. And a mixture of the linear polyester and the copolyester as described above. Examples of the third component include isophthalic acid, naphthalene-2,6-dicarboxylic acid, adipic acid, diphenyl ether-4,4'-
Acid components such as dicarboxylic acid and sebacic acid, propylene glycol, neopentyl glycol, diethylene glycol, cyclohexanedimethanol, 2,2-bis (4
Examples thereof include glycol compounds such as -hydroxyphenyl) propane, oxyacids such as p-oxybenzoic acid and p-hydroxyethoxybenzoic acid. The PET
Has an intrinsic viscosity of 0.5 when measured at 30 ° C with a phenol / tetrachloroethane mixed solvent (1/1 weight ratio) solution.
It is preferably not less than 0.5, more preferably not less than 0.55.

The polybutylene terephthalate resin (hereinafter abbreviated as PBT) in the present invention is a linear polyester obtained by polycondensing terephthalic acid or dialkyl terephthalate and 1,4-butanediol, and terephthalic acid or dialkyl terephthalate. It includes a copolyester having 3,4-butanediol as a main component and a third component copolymerizable therewith, and a mixture of the linear polyester and the copolyester. Examples of the third component include those in the case of PET. In addition,
The PBT preferably has an intrinsic viscosity of 0.6 or more, and more preferably 0.65 or more, which is obtained by measuring at 30 ° C. with a phenol / tetrachloroethane mixed solvent solution (1/1 weight ratio).

One of the important things in the present invention is that the polyester resin in the present invention contains the PET and the PBT, and further, the blending ratio (A) / PET (A) / PBT (B) /
(B) is 0.2 to 2 (weight ratio), preferably 0.3 to 1.
That is 7. If the blending ratio is less than 0.2, PET original properties such as heat resistance and rigidity cannot be exhibited. If the blending ratio is more than 2, the crystallization promoting effect of PBT is not exhibited and the low temperature gold is not produced. The glass fiber in the present invention, which is difficult to mold in a mold, can be any of alkali-containing glass, low-alkali glass and non-alkali glass, and the length in the polyester resin composition is 0.02 to 2 mm. And particularly preferably 0.05 to 1 mm. This glass fiber, since the glass fiber may be broken during the kneading with the polyester resin, as the size of the glass fiber when subjected to kneading, usually,
The length is preferably 0.1 to 6 mm. Moreover, the diameter of such glass fiber is usually sufficient to be 1 to 20 μm. The form of the glass fiber is not particularly limited, and may be roving, milled fiber, chopped strand, or the like. Further, it is preferable that the glass fiber is surface-treated, for example, silane-treated, borane-treated, gallan-treated, chromium-treated, and the like, and the epoxy resin is bundled. This is because the adhesion between the polyester resin and the glass fiber is improved by performing such treatment.

Talc in this invention is used as a nucleating agent. Talc having an average particle size of 0.5 to 10 μ, particularly 1 to 8 μ is preferable.

Examples of the polyalkylene glycol compound in the present invention include polyethylene oxide obtained by polymerizing ethylene oxide and a substituted ethylene oxide such as propylene oxide, epichlorohydrin and styrene oxide, and 3,3-bis (chloromethyl) oxetane. Polypropylene glycol obtained by polymerizing a 4-membered ring ether, a polyalkylene glycol such as polypropylene obtained by polymerizing a 5-membered ring ether such as tetrahydrofuran, and a hydroxyl group at both ends of the polyalkylene glycol. Examples include polyalkylene glycol dialkyl ethers blocked with groups. In this invention, it is possible to use the polyalkylene glycol, the polyalkylene glycol has a hydroxyl group bonded to both ends of the polyalkylene glycol PE
It is preferable to use a polyalkylene glycol dialkyl ether rather than the above polyalkylene glycol because it may cause a transesterification reaction with T and PBT. Furthermore, among the above-mentioned polyalkylene glycol dialkyl ethers, polyethylene glycol dialkyl ethers are particularly preferable, and in that case, the alkyl groups at both ends thereof preferably have 1 to 10 carbon atoms, particularly 1 to 3 carbon atoms,
The molecular weight is preferably 300 to 3000, particularly 500 to 2000. When the number of carbon atoms of the alkyl groups at both ends exceeds 10, the influence of the alkyl groups becomes large and the mechanical strength of the polyester resin composition may decrease. If the molecular weight is less than 300, the molding processability of the polyester resin may not be improved, and if the molecular weight is more than 3000, the mechanical properties may deteriorate.

One of the important things in this invention is that the polyester resin composition has a glass fiber content of 5 to 65 parts by weight, preferably 10 to 55 parts by weight, based on 100 parts by weight of the polyester resin. The blending amount of talc is 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, and the blending amount of the polyalkylene glycol compound is 0.5 to 5 parts by weight, preferably 1
It is to contain the said polyester resin, glass fiber, talc, and a polyalkylene glycol compound in the ratio of -3 weight part.

If the content of the glass fiber is less than 5 parts by weight, the impact resistance and rigidity of the polyester resin composition are insufficient, and even if it exceeds 65 parts by weight, the impact resistance of the polyester resin composition is insufficient. It does not improve as much as the compounding amount, and the specific gravity becomes large and the moldability decreases.

If the compounding amount of the talc is less than 0.5 parts by weight, the moldability becomes poor, and if it is more than 10 parts by weight, the rigidity and the like decrease.

If the blending amount of the polyalkylene glycol compound is less than 0.5 parts by weight, the plasticizing effect is insufficient and the moldability is poor, and if it is more than 5 parts by weight, the polyester resin composition has poor rigidity and heat resistance. It becomes defective.

In the polyester resin composition according to the present invention, it is preferable to add an antioxidant in addition to the above components. By adding an antioxidant, it is possible to prevent the polyester resin composition from being burnt during the molding process, to improve the appearance of the molded product and to prevent the oxidative deterioration of the molded product to improve its mechanical strength. Can be prevented.

Examples of the antioxidant include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-
Methylene-bis- (4-ethyl-6-t-butylphenol), 4,4'-thiobis (3-methyl-6-t-butylphenol), 4,4'-butylidenebis- (3-methyl-6-t-) Butylphenol), tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4-hydroxyphenyl) propionate] methane, 1,1,3-tris-
Phenolic compounds such as (2-methyl-4-hydroxy-5-t-butylphenyl) butane, phenyl-β
Amine compounds such as naphthylamine, N, N′-diphenyl-p-phenylenediamine, tris (nonylphenyl) phosphite, triphenylphosphite,
Examples thereof include phosphorus compounds such as trioctadecyl phosphite and diphenylisodecyl phosphite, and sulfur compounds such as dilauryl thiodipropionate, dimyristyl thiodipropionate and distearyl thiodipropionate.

With respect to this polyester resin composition, it is preferable to use a phenol compound and a phosphorus compound together in the various antioxidants.

The mixing ratio of the antioxidant in the polyester resin composition is preferably 2 parts by weight or less, particularly 0.1 to 1.0 part by weight, based on 100 parts by weight of the polyester resin. Even if the blending amount of the antioxidant exceeds 1 part by weight, there is no effect according to the increase of the blending amount.

In addition to the antioxidant, the polyester resin composition may contain various additives such as a flame retardant, an ultraviolet absorber, an antistatic agent, a lubricant, a release agent and a colorant.

Examples of the flame retardant include polybromostyrene, decabromodiphenyl ether, halogen flame retardants such as tetrabromobisphenol A, ammonium phosphate, tricresyl phosphate, triethyl phosphate, phosphorus flame retardants such as acidic phosphate ester, Tin oxide,
Examples include inorganic flame retardants such as antimony trioxide.

Examples of the ultraviolet absorber include salicylic acid type ultraviolet absorbers such as phenyl salicylate and pt-butylphenyl salicylate, benzophenone type ultraviolet absorbers such as 2,4-dihydroxybenzophenone and 2-dihydroxy-4-methoxybenzophenone, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole,
2- (2'-hydroxy-5'-t-butylphenyl)
Examples thereof include benzotriazole-based UV absorbers such as benzotriazole.

Examples of the antistatic agent include nonionic antistatic agents such as polyoxyethylene alkylamines and polyoxyethylene alkylamides, alkyl sulfonates,
Examples thereof include anionic antistatic agents such as alkylbenzene sulfonate, cationic antistatic agents such as quaternary ammonium chloride and quaternary ammonium sulfate, and amphoteric antistatic agents such as alkyl betaine type and alkyl imidazoline type.

Examples of the lubricant include aliphatic hydrocarbons, higher aliphatic alcohols, fatty acid amides, metal soaps, and fatty acid ester lubricants.

Examples of the release agent include carnauba wax,
Examples include paraffin wax and silicone oil.

As the colorant, an ordinary colorant used for coloring plastics can be used.

The polyester resin composition according to the present invention can be produced by blending the polyester resin, glass fiber, talc, polyalkylene glycol compound and the various additives described above. The method of blending is not particularly limited, and for example, a method of premixing all components and kneading the obtained premix, the PET and PBT are premixed or kneaded, and talc and a polyalkylene glycol compound are added. And finally kneading the glass fiber, the above
Examples thereof include a method in which glass fibers are blended with PET or the above-mentioned PBT, or after the polycondensation, glass fibers are added, and then other components are added, and these are mixed or kneaded. The mixing is, for example, a ribbon blender, a tumble mixer, a Henschel mixer, the kneading is an open roll,
It can be performed with a Banbury mixer, a single screw extruder, a twin screw extruder, a single reciprocating screw kneader, or the like.

The polyester resin composition thus obtained is molded into various molded products by various molding methods such as injection molding, mold molding, and extrusion molding.

[Effect of the Invention] The polyester resin composition according to the present invention is
It has excellent moldability in a low temperature mold at ℃, and has excellent heat resistance and mechanical properties such as rigidity and internal impact resistance. Therefore, the polyester resin composition can be suitably formed into interior and exterior parts of automobiles and home electric appliances which are required to have good mechanical properties and a beautiful surface appearance.

EXAMPLES Next, the present invention will be described more specifically by showing Examples and Comparative Examples of the present invention.

(Examples 1 to 9 and Comparative Examples 1 to 9) PET, PBT, glass fiber, talc, polyethylene glycol compound, and antioxidant were prepared, and these were mixed and kneaded at the blending ratio shown in Table 1 to form pellets. After the solidification, the obtained pellets were dried and then injection-molded to prepare a test piece. The tensile strength of the obtained test piece was measured according to JIS K7113, and the gloss was measured according to JIS K7105. The measurement results are shown in Table 1. The low temperature moldability of the polyester resin composition is 80 ° C. using a polyester resin composition having a blending ratio shown in Table 1.
A flat plate (8 cm × 8 cm) was injection-molded with and the appearance of this molded product was visually observed and evaluated. The results are shown in Table 1. The evaluation symbols and evaluation contents in Table 1 are shown below.

The notes on the symbols in Table 1 are shown below.

Claims (2)

[Claims] 1. 100 parts by weight of a polyester resin containing a polyethylene terephthalate resin (A) and a polybutylene terephthalate resin (B) and having a compounding ratio (A) / (B) of the both of 0.2 to 2 and glass fiber. A polyester resin composition comprising 5 to 65 parts by weight, talc 0.5 to 10 parts by weight, and a polyalkylene glycol compound 0.5 to 5 parts by weight. 2. The polyester resin composition according to claim 1, wherein the polyalkylene glycol compound is polyethylene glycol having both ends blocked with alkyl groups.