JPH0859971A - Connector resistant to moist heat - Google Patents

Abstract

PURPOSE: To provide a connector capable of being used in wide areas as well as in hot and moist conditions, excellent in impact resistance, heat resistance, terminal holding power and connector holding power and useful for automobiles having improved moist heat resistance. CONSTITUTION: This connector is molded from a polyester resin composition by adding 0.01-5 pts.wt. of a hindered amine compound to 100 pts.wt. of the sum total of 50-98 pts.wt. poly(1,4-butylene terephthalate), 1-40 pts.wt. aromatic carbonate and 1-40 pts.wt. multiple layer polyacrylic acid ester having a core- shell structure consisting of a rubbery primary stage and a hard final stage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connector made of a specific resin composition, and more particularly to an automotive connector which is excellent in impact resistance, rigidity and heat resistance, and particularly excellent in moist heat resistance.

[0002]

2. Description of the Related Art Generally, thermoplastic polyester resins represented by poly (1,4-butylene terephthalate) (hereinafter referred to as PBT resin) and poly (ethylene terephthalate) (hereinafter referred to as PET resin) have moldability, mechanical properties, Due to its excellent electrical properties and chemical resistance, it is widely used as an engineering plastic in automobiles, electric / electronic devices, and other applications. Conventionally, general-purpose plastics such as polypropylene and thermosetting resins such as phenolic resins have been used as the materials for these parts, but thermoplastic polyesters have been required in the pursuit of higher functionality, higher performance and improved moldability. Has been replaced by. In particular, automotive connectors, in particular, are linear polyester resins, particularly poly (1,4-butylene terephthalate), from the viewpoint of reliability, since polyamide resins, which have been widely used in the past, have large changes in dimensions and mechanical properties due to moisture absorption. Has come to be used.

In recent years, there is a growing need for weight reduction of automobiles, and it is expected that the connector itself will become thinner and lighter, and it is considered that the conventional connector using PBT resin will have a problem of breakage during assembly and use. Therefore, in general, as a means for improving the impact resistance of a polyester resin, a linear polyester resin such as a PBT resin has an aromatic polycarbonate resin as a modifier and a core-shell structure consisting of a rubber-like initial stage and a hard final stage. It is disclosed in JP-B-2-2898 and JP-A-52-150466 that extremely excellent impact resistance is imparted by blending with a multi-layered polyacrylic acid ester resin, and these effects are obtained. As described in the specification and examples.

On the other hand, PBT resin automobile connectors are used in various parts by taking advantage of their excellent characteristics.
Among them, their use in more severe environments such as high humidity and high humidity is also increasing. However, a connector formed of a composition obtained by combining the PBT resin, the aromatic polycarbonate resin, and the core-shell type multi-layer polyacrylic acid ester resin described above has a large deterioration under high temperature and high humidity, and thus has excellent initial characteristics. Its use will be limited. Japanese Patent Application Laid-Open No. 4-266963 discloses an automotive connector formed of the above-mentioned composition, but does not describe a method for improving the wet heat resistance.

In the first place, thermoplastic polyesters and aromatic polycarbonates are generally inferior in moist heat resistance to polyamide resins and the like because of ester bonds in the main chain, and 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. In addition, JP-A-46-53
89, Japanese Patent Publication No. 56-21766, JP-A-6
No. 0-228553, a method of blending a carbodiimide, JP-A-60-208323, JP-A-5-209117, and JP-B-62-42.
It has been proposed to improve the wet heat resistance of a thermoplastic polyester resin 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. 941. However, in such a method, although the strength of the moist heat resistance is improved, the improvement of the elongation is not sufficient, so that the flexibility of the hinge portion and the housing portion of the automobile connector having a large number of thin portions, which has been increasing in recent years, deteriorates. It happens and is unreliable. Further, since it reacts with the terminal group of the polymer, the molecular weight increases before and after the compounding, and reworkability remarkably deteriorates when it is recycled.

[0006]

OBJECT OF THE INVENTION The object of the present invention is to provide an automotive connector which is excellent in impact resistance, heat resistance, terminal holding power, connector holding power, lock strength and hinge characteristics, and particularly excellent in moist heat resistance and which can be used in more parts. To provide.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that (A) poly (1,4-butylene terephthalate) resin, or a small amount of aliphatic / aromatic resin. Of a dicarboxylic acid group or an aliphatic diol and 1,4-butylene terephthalate 50-
98 parts by weight, (B) aromatic polycarbonate resin 1 to 4
0 parts by weight, and (C) 1 to 40 parts by weight of a multilayer polyacrylate resin having a core-shell structure consisting of a rubber-like initial stage and a thermoplastic and hard final stage, for a total of 100 parts by weight, (D) An automotive connector formed from a polyester resin composition containing 0.01 to 5 parts by weight of a hindered amine compound and having improved wet heat resistance.

The PBT resin used as the component (A) in the present invention is polybutylene terephthalate obtained by polycondensing 1,4-butanediol and terephthalic acid or its lower alcohol ester, and polybutylene terephthalate. It may be a copolymer containing 60% by weight or more. The monomers to be copolymerized are isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid,
Aromatic, aliphatic, alicyclic polybasic acids such as diphenyldicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, and cyclohexanedicarboxylic acid, and ester-forming derivatives thereof, hydroxybenzoic acid, and hydroxynaphthoic acid Hydroxycarboxylic acid and its ester-forming derivative, lower alkylene glycol such as ethylene glycol, 1,3-propanediol, 1,6-hexanediol, 1,8-octanediol, cyclohexanedimethanol and cyclohexanediol, bisphenol A, 4 , 4'-dihydroxybiphenyl and other aromatic alcohols, bisphenol A ethylene oxide 2 mol adduct alcohol, bisphenol A propylene oxide 2 mol adduct alkylene oxide adduct al Examples thereof include polyhydroxy compounds such as alcohol, glycerin, and pentaerythritol, and ester-forming derivatives thereof. These dicarboxylic acids and hydroxy compounds can be used alone or in combination of two or more, but polybutylene terephthalate homopolymer is particularly preferable. The effects of the present invention are most prominent.

The PBT resin of component (A) has a temperature of 25 ° C. measured by a dilute solution using orthochlorophenol as a solvent.
Those having an intrinsic viscosity of 0.3 to 2.0 dl / g are preferable, and those having an intrinsic viscosity of 0.5 to 1.5 dl / g are particularly preferable. If the intrinsic viscosity is less than 0.3 dl / g, the mechanical strength and thermal properties of the connector will be insufficient, while if it is higher than 2.0 dl / g, the fluidity to the thin portion of the connector will deteriorate and molding It is not preferable because it causes defects.

In the present invention, the PBT resin as the component (A) accounts for 50 to 98 parts by weight in the resin composition. When the PBT resin is less than 50 parts by weight, mechanical strength, chemical resistance and weather resistance cannot be obtained. If it exceeds 98 parts by weight, sufficient impact cannot be obtained.

The aromatic polycarbonate resin used as the component (B) of the present invention is a resin produced from a divalent phenol and a carbonate precursor such as phosgene, halogen formate or carbonate ester. Here, the divalent phenols include bisphenol A, hydroquinone, 2,2-bis- (4-hydroxyphenyl) pentane, 2,4'-dihydroxyphenylmethane, bis- (2-hydroxyphenyl) methane and bis-.
(4-hydroxyphenyl) methane, bis- (4-hydroxy-5-nitrophenyl) methane, 1,1-bis-
(4-hydroxyphenyl) ethane, 3,3-bis-
(4-hydroxyphenyl) pentane, 2,2'-dihydroxydiphenyl, 2,6-dihydroxynaphthalene, bis- (4-hydroxyphenyl) sulfone,
2,2-bis- (3,5-dimethyl-4-hydroxyphenyl) propane, 2,4'-dihydroxyphenyl sulfone, bis- (4-hydroxyphenyl) diphenyl ether, bis- (4-dihydroxy-5-propylphenyl) ) Methane, bis- (4-hydroxyphenyl)
Cyclohexylmethane, 2,2-bis- (4-hydroxyphenyl) -1-phenylpropane, 4,4'-dihydroxy-3,3'-dichlorophenyl ether, 4,
4'-dihydroxy-2,5-dichlorophenyl ether and the like. Among these, those using bisphenol A as the dihydric phenol and phosgene as the carbonate precursor are preferably used and can be easily obtained from several sources.

In the present invention, the blending amount of the aromatic polycarbonate resin as the component (B) is 1 to 49 parts by weight, preferably 3 to 30 parts by weight. When it is less than 1 part by weight, the impact improving effect is not sufficient, and when it exceeds 40 parts by weight, the moldability is deteriorated such that the fluidity of the composition is lowered and the crystallization rate from the melt is remarkably reduced, which is not preferable. .

The core-shell type multi-layer polyacrylic acid ester resin comprising the rubber-like initial stage and the hard final stage used for the component (C) of the present invention has an initial elastic stage of about 25.
.About.95% by weight and a final hard stage of about 5 to 75% by weight, and is a multilayer polyacrylate resin having a core-shell structure described in JP-A-52-150466. Specifically, the initial elastic stage is composed of an alkyl acrylate having 1 to 6 carbon atoms, a cross-linking monomer having a plurality of addition-polymerizable reactive groups, and a graft-bonding monomer. Alkyl methacrylate having 1 to 4 carbon atoms is used in the hard stage. These core-shell type multi-layer polyacrylic acid ester resins are easily available from Rohm and Haas under the trade name of Acryloid KM330, from Kureha Kagaku under the trade name of Paraloid EXL2315, and from several other sources.

In the present invention, the compounding amount of the core-shell type multi-layer polyacrylic acid ester resin as the component (C) is 1 to 49 parts by weight, preferably 2 to 20 parts by weight. If it is less than 1 part by weight, the impact improving effect is not sufficient, and if it exceeds 40 parts by weight, the fluidity and rigidity of the composition are reduced, which leads to a reduction in the terminal holding force and the connector holding force, which is not preferable.

A characteristic of the present invention is the use of the hindered amine compound of component (D),
The compound has one or more structures represented by the following formula (1).

[0016]

Embedded image

In the formula, R1, R2, R3, and R4 have 1 to 1 carbon atoms.
6 alkyl 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) zebacate,
Bis- (1,2,2,6,6-pentamethyl-4-piperidyl) terephthalate, N, N'-bis- (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 [(2,2,2
6,6-Tetramethyl-4-piperidyl) imino]],
Tetrakis (1,2,2,6,6-pentamethyl-4-
Piperidyl) 1,2,3,4-butanetetracarboxylate, tetrakis (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-
Condensation product of (2,4,8,10-tetraoxaspiro [5,5] undecane) diethanol, 1,2,3,4-
Butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro Examples include condensates of [5,5] undecane) diethanol.

The blending amount of the hindered amine compound is PB
0.01 to 5 parts by weight, preferably 0 to 100 parts by weight of a total of 100 parts by weight of the T resin, the aromatic polycarbonate resin, and the multi-layered polyacrylic acid ester resin having a core-shell structure consisting of a rubber-like initial stage and a hard final stage. 0.03 to 3 parts by weight. If it is 0.01 part by weight or less, the effect of the present invention cannot be sufficiently exhibited and the wet heat resistance is not improved. When the amount is 5 parts by weight or more, the excellent mechanical properties originally possessed by the above composition, particularly the tensile elongation at break, are lowered, and the properties of the hinge part and the lance part of the connector are deteriorated, which is not suitable for automobile connectors.

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, other thermoplastic resins may be used in the composition of the present invention 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, 6, 6, 12 and mixtures thereof, copolymers, polyphenylene ether and the like.

Further, various fillers can be used in the composition of the present invention depending on the purpose and application. Examples of those that can be used include fibrous fillers such as glass fibers, carbon fibers, metal fibers, needle fillers such as wollastonite, asbestos, potassium titanate whiskers, magnesium silicate whiskers, glass flakes, mica. , Plate-like fillers such as talc, glass beads, spherical fillers such as glass balloons, and the like. The above-mentioned composition using these fillers is particularly used for multipolar connectors and junction blocks having a larger number of poles.

The method for producing the composition and connector of the present invention is not particularly limited, and may be adjusted by a known method. For example, a blended PBT resin, aromatic polycarbonate, multi-layer acrylic ester resin and hindered amine compound are mixed in a single-screw or twin-screw extruder, roll,
A Banbury mixer is melt-mixed to produce a composition, and the composition is injection-molded to obtain a connector.

[0023]

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. Bending Modulus According to ASTM D790, it was performed using ASTM I test pieces. 3. 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. 4. Connector physical properties The terminal holding force was measured using a 12-pole female C-type connector.

Examples 1 to 5 An aromatic polycarbonate composed of PBT resin having an intrinsic viscosity of 0.95, bisphenol A and phosgene (hereinafter referred to as P
C), the core-shell type multilayer polyacrylic acid ester (CSA) and the hindered amine compound were uniformly mixed in advance to the composition shown in Table 1 and then set to 250 ° C. 35
The mixture was kneaded and pelletized by a twin-screw extruder with a mmφ vent.
Next, the resulting resin composition pellets were heated to a barrel temperature of 250.
Injection molding at 80 ° C. and a mold temperature of 80 ° C. to prepare ASTMI tensile test pieces and automotive connectors. Further, the obtained pellets, tensile test pieces, automotive connectors at 121 ° C,
MFR, tensile strength and terminal holding force were measured after wet heat deterioration with a pressure cooker under a condition of 2 atm.

Examples 6 to 10 Tests were carried out in the same manner as in Example 3 except that the hindered amine compound was added in the composition shown in Table 2.

Comparative Examples 1 to 3 Tests were carried out in the same manner as in Examples 1 to 5 except that PBT resin having an intrinsic viscosity of 0.95, PC and CSA were compounded in the compositions shown in Table 3.

Comparative Examples 4 to 5 Tests were conducted in the same manner as in Examples 3 and 6 to 9 except that the hindered amine compound was added in the composition shown in Table 3.

The following raw materials were used as the raw materials in the table. PBT1: manufactured by Kuraray Co., Ltd. ([η] = 0.95) PC: Panlite L1250 CSA manufactured by Teijin Chemicals Co., Ltd .: Paraloid EXL231 manufactured by Kureha Chemical Co., Ltd.
5 HA1: 1,2,3,4-butanetetracarboxylic acid and 2,2,6,6-tetramethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9- (2 ，
Condensate with 4,8,10-tetraoxaspiro [5,5] undecane) diethanol HA2: Dimethyl-1- (2-hydroxyethyl) -4-hydroxy 2,2,6,6-tetramethylpiperidine succinate

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

As is apparent from the above description and examples,
For a total of 100 parts by weight of poly (1,4-butylene terephthalate), an aromatic polycarbonate, and a multi-layer polyacrylic acid ester compound having a core-shell structure consisting of a rubber-like initial stage and a hard final stage, a hindered amine compound 0 An automobile connector formed from a polyester resin composition containing 0.01 to 5 parts by weight is an automobile connector having excellent impact resistance, heat resistance, terminal holding power, connector holding power, and particularly excellent moist heat resistance. It can also be used under high temperature and high humidity.

Claims (1)

[Claims] 1. A poly (1,4-butylene terephthalate) resin (A) or a copolymer of 1,4-butylene terephthalate and a small amount of an aliphatic / aromatic dicarboxylic acid or an aliphatic diol in an amount of 50 to 98 parts by weight. , (B) 1-40 parts by weight of aromatic polycarbonate resin, and (C) 1-40 parts by weight of multi-layer polyacrylate resin having a core-shell structure consisting of a rubber-like initial stage and a thermoplastic and hard final stage. And 100 parts by weight in total,
(D) A moisture and heat resistant connector formed from a polyester resin composition containing 0.01 to 5 parts by weight of a hindered amine compound.