JPH0848860A - Thermoplastic polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, capable of improving the wet heat resistance without deteriorating the molding processability and mechanical characteristics and useful for electrical and electronic parts, etc., by blending a specific hindered amine compound with a thermoplastic polyester resin. CONSTITUTION:This composition is obtained by blending (A) 100 pts.wt. thermoplastic polyester resin with (B) 0.01-5 pts.wt. hindered amine compound. Furthermore, e.g. a polyethylene terephthalate having 0.5-1.5dl/g intrinsic viscosity is used as the component (A) and a compound having one or more structures of the formula (R1 to R4 are each a 1-6C alkyl), specifically 4-benzoyloxy-2,2,6,6- tetrumethylpiperidine, etc., are preferably used as the component (B).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyester resin composition having improved wet heat resistance without impairing the moldability, mechanical properties and electrical properties of thermoplastic polyester. The present invention can be widely used in electronic / electrical parts, automobile parts, mechanical parts and the like.

[0002]

2. Description of the Related Art Generally, thermoplastic polyester resins represented by poly (1,4-butylene terephthalate) and poly (ethylene terephthalate) have moldability,
Due to its excellent mechanical properties, electrical properties and chemical resistance, it can be used as an engineering plastic for automobiles,
Widely used in applications such as electronic devices. Conventionally, general-purpose plastics such as polypropylene and thermosetting resins such as phenolic resins have been used as materials for these parts, but they have been replaced by thermoplastic polyesters that require higher functionality, higher performance, or improved moldability. It has started to be done. However, in recent years, the thermoplastic polyester has been increasingly used in a more severe environment such as high temperature and high humidity, and it is becoming difficult to satisfy the required quality.

Since thermoplastic polyesters are generally inferior in moist heat resistance to polyamide resins and the like due to ester bonds in the main chain, attempts have been made to improve the moist heat resistance. As a measure for this, it is effective to reduce the concentration of the carboxyl group at the polymer terminal, and a solid phase polymerization method has been generally proposed as a means for this. Further, JP-A-46-5389 and JP-B-56-2.
1766, the method of incorporating carbodiimide described in JP-A-60-228553, JP-A-60-208323, and JP-A-5-209117.
It is proposed to improve the wet heat resistance of a thermoplastic polyester by adding a compound that reacts with a carboxyl group at the polymer terminal, as in the method of blending an epoxy compound described in Japanese Patent Publication No. 62-29441. Has been done.

However, in such a method, although the strength of the moist heat resistance is improved, the elongation is not sufficiently improved, so that the flexibility of the thin portion is lowered depending on the molded product, resulting in lack of reliability. Further, since it reacts with the terminal group of the polymer, the molecular weight increases before and after the compounding, the moldability is remarkably deteriorated, and the recycling property is not suitable.

[0005]

OBJECT OF THE INVENTION It is an object of the present invention to provide a resin composition having improved excellent moldability and characteristics of thermoplastic polyester without impairing such characteristics.

[0006]

DISCLOSURE OF THE INVENTION As a result of intensive studies for achieving the above-mentioned object, the present inventors have formulated a specific hindered amine compound as a means for improving the moist heat resistance of a thermoplastic polyester. As a result, it was found that a product satisfying the above-mentioned object was obtained, and the present invention was reached. That is, the present invention relates to a thermoplastic polyester resin 1
0.01 parts by weight of a hindered amine compound 0.01
To 5 parts by weight of the resin composition.

The thermoplastic polyester resin in the present invention includes aliphatic dicarboxylic acids such as sebacic acid and adipic acid, aromatic dicarboxylic acids such as isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid and diphenyldicarboxylic acid, and cyclohexanedicarboxylic acid. Alicyclic dicarboxylic acids and their derivatives with dihydroxy compounds such as ethylene glycol, propylene glycol, butylene glycol, hexanediol, cyclohexanedimethanol, cyclohexanediol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and bisphenol A. It is a polymer obtained by a condensation reaction. These dicarboxylic acids and dihydroxy compounds can be used alone or in combination of two or more.

Specific examples of the thermoplastic polyester resin of the present invention include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycyclohexane dimethylene terephthalate and copolymers thereof. Among these, when polyethylene terephthalate, polybutylene terephthalate and polyethylene terephthalate / polycyclohexanedimethylene terephthalate copolymer are used, the effect of the present invention is most remarkably exhibited.

The thermoplastic polyester of the present invention includes:
Intrinsic viscosity at 25 ° C. measured with a dilute solution of orthochlorophenol as a solvent is 0.3 to 2.0 dl /
g is preferable, and particularly 0.5 to 1.5 dl / g
Are preferred. If the intrinsic viscosity is less than 0.3 dl / g, mechanical strength and thermal properties will be insufficient, while if it is higher than 2.0 dl / g, moldability will be poor, which is not preferable.

The hindered amine compound used in the present invention has at least one structure represented by the following formula (1) in the compound.

[0011]

Embedded image In the formula, R1, R2, R3, and R4 are alkyl having a C number of 1 to 6, and may be different or the same.

As a specific example, 4-benzoyloxy-
2,2,6,6-tetramethylpiperidine, bis-
(2,2,6,6-Tetramethyl-4-piperidyl) adipate bis- (2,2,6,6-tetramethyl-4-
Piperidyl) suberate, bis- (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis-
(2,2,6,6-tetramethyl-4-piperidyl) phthalate, bis- (2,2,6,6-tetramethyl-4)
-Piperidyl) terephthalate, bis- (1,2,2,
6,6-pentamethyl-4-piperidyl) sebacate,
Bis- (1,2,2,6,6-pentamethyl-4-piperidyl) terephthalate, N, N'-bis- (2,2,2
6,6-tetramethyl-4-piperidyl) adipamide,
Bis- (1,2,2,6,6-pentamethyl-4-piperidyl) -n-butyl (3,5-di-t-butyl-4-
Hydroxybenzyl) malonate, bis- (2,2,
6,6-Tetramethyl-4-piperidyl) -n-butyl (3,5-di-t-butyl-4-hydroxybenzyl)
Malonate, butane tetracarboxylic acid tetra- (2,
2,6,6-tetramethyl-4-piperidyl) ester, 1- [2- [3- (3,5-di-t-butyl-4-
Hydroxyphenyl) propionyloxy] ethyl]-
4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] 2,2,6,6-tetramethylpiperidine, poly [[6- (1,1,3,3-
Tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethylpiperidyl) imino] hexamethylene [(2,2,6
6-Tetramethyl-4-piperidyl) imino]], tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, tetrakis (2,2,2) 6,6-Tetramethyl-4-
Piperidyl) 1,2,3,4-butanetetracarboxylate, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate, 1,2,3, 4-butanetetracarboxylic acid and 2,2,6,6-tetramethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9- (2,2
Condensation product of 4,8,10-tetraoxaspiro [5,5] undecane) diethanol, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol And a condensate of β, β, β ′, β′-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro [5,5] undecane) diethanol.

The content of the hindered amine compound is 0.01 to 5 parts by weight, preferably 0.03 to 3 parts by weight, based on 100 parts by weight of the thermoplastic polyester. 0.01
If the amount is less than 5 parts by weight, the effect of the present invention cannot be fully exerted, and
When it is more than 1 part by weight, the excellent mechanical properties originally possessed by the thermoplastic polyester are impaired.

Further, the composition of the present invention may be used in combination with various additives usually used within the range not impairing the object of the present invention. Examples of those that can be used are flame retardants, flame retardant aids, ultraviolet absorbers, lubricants, mold release agents, heat stabilizers, antistatic agents, colorants including dyes and pigments, etc., which are used according to the purpose. .

Further, in the composition of the present invention, another thermoplastic resin can be used within the range not impairing the object of the present invention. Examples of what can be used are polyethylene,
Examples thereof include polyolefin resins such as polypropylene and mixtures thereof, copolymers, polyamide resins such as nylon 6, 66, 12 and mixtures thereof, copolymers, polyphenylene ether and the like.

Further, the composition of the present invention can use various fillers which are usually used within the range not impairing the object of the present invention. Examples of materials that can be used include fibrous fillers such as glass fiber, carbon fiber and metal fiber,
Plate-shaped fillers such as glass flakes, mica, talc, wollastonite, potassium titanate, magnesium silicate, aluminum silicate, sepiolite, zeolite,
Needle-like fillers such as asbestos, glass beads, spherical fillers such as glass balloons, and titanium oxide.

The method for producing the composition of the present invention is not particularly limited, and the thermoplastic polyester and the hindered amine compound previously blended are melt-mixed with a single-screw or twin-screw extruder, roll, Banbury mixer,
Single-screw or twin-screw extruder, roll, Banbury mixer-method of blending a hindered amine compound with molten thermoplastic polyester, after melt-mixing the thermoplastic polyester and the hindered amine compound to prepare a master pellet, the hindered amine compound is For example, a method of mixing with a thermoplastic polyester so as to obtain a predetermined amount is used.

[0018]

EXAMPLES The effects of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.
The method of measuring the characteristics in the examples is as follows. 1. Tensile Strength According to ASTM D638, it was performed using ASTM I test pieces. 2. Measurement of MFR It was performed according to ASTM D1238. Unless otherwise specified, pre-drying was performed at 120 ° C for 2 hours at a measurement temperature of 25.
It was carried out under the conditions of 0 ° C. and a load of 325 g for a holding time of 5 minutes.

Examples 1 to 6 Using a polybutylene terephthalate (hereinafter referred to as PBT) having an intrinsic viscosity of 0.95, the hindered amine compound was uniformly mixed in advance with the composition shown in Table 1 and then set at 250 ° C. with a 35 mmφ vent. It was kneaded and pelletized by a shaft extruder. Next, the obtained resin composition pellets were heated to a barrel temperature of 2
Injection molding was performed at 50 ° C. and a mold temperature of 80 ° C. to prepare an ASTM I tensile test piece. Further, the pellets and the tensile test pieces thus obtained were subjected to wet heat deterioration with a pressure cooker under the condition of 121 ° C. and 2 atm, and then the MFR and the tensile strength were measured.

Example 7 A test was conducted in the same manner as in Example 3 except that PBT having an intrinsic viscosity of 0.85 was used.

Example 8 A polyethylene terephthalate (hereinafter referred to as PET) having an intrinsic viscosity of 0.85 was used, except that the MFR was measured at 275 ° C.
The test was conducted in the same manner as in Example 3.

Comparative Examples 1 and 2 Tests were conducted in the same manner as in Example 3 except that the hindered amine compound was blended in the composition shown in Table 2.

Comparative Example 3 A test was conducted in the same manner as in Example 8 except that the composition of the hindered amine compound was adjusted to the composition shown in Table 2.

Comparative Example 4 A test was conducted in the same manner as in Example 3 except that an epoxy compound was used instead of the hindered amine compound.

Comparative Example 5 A test was conducted in the same manner as in Example 3 except that polycarbodiimide was used instead of the hindered amine compound.

The following raw materials were used as the raw materials in the table. PBT1: Kuraray Co., Ltd. ([η] = 0.95) PBT2: Kuraray Co., Ltd. ([η] = 0.85) PET: Kuraray Co., Ltd. ([η] = 0.85) HA1: 1: 1,2 , 3,4-Butanetetracarboxylic acid and 2,2,6,6-tetramethyl-4-piparizinol and β, β, β ', β'-tetramethyl-3,9- (2,2
Condensate with 4,8,10-tetraoxaspiro [5,5] undecane) diethanol HA2: Dimethyl-1- (2-hydroxyethyl) -4-hydroxy 2,2,6,6-tetramethylpiperidine succinate EP: Epoxy compound (glycidyl-t-butylbenzoate) CDI: Polycarbodiimide (Stavaxol P manufactured by Bayer KK)

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

As is apparent from the above description and examples,
By blending 0.01 to 5 parts by weight of a hindered amine compound with 100 parts by weight of a thermoplastic polyester, a thermoplastic polyester resin composition having improved moist heat resistance without impairing moldability and mechanical properties is provided. .

Claims (1)

[Claims] 1. A thermoplastic polyester resin composition prepared by blending 0.01 to 5 parts by weight of a hindered amine compound with 100 parts by weight of a thermoplastic polyester resin.