JPH11236492A - Resin composition for connector and molding consisting of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a connector part material equipped with a high impact resistance and hydrolysis resistance, and also having a high elastic modulus. SOLUTION: This resin composition for connector consists of (A) 100 pts.wt. thermoplastic aromatic polyester resin having <=20 eq/ton terminal carboxyl group, (B) 2-10 pt.wt. impact resistance improving agent consisting of a polyorganosiloxane rubber and a polyalkyl(meth)acrylate rubber, and (C) 0.01-5 pt.wt. epoxy compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a resin composition for a connector and a molded article made thereof. More specifically, a resin composition for a connector having impact resistance, excellent hydrolysis resistance and high rigidity and a molded article comprising the same, and particularly a resin composition for a connector suitable for use in automobiles and a molded article comprising the same About.

[0002]

2. Description of the Related Art Polybutylene terephthalate (hereinafter referred to as P
Thermoplastic polyester resins such as resins have excellent moldability, mechanical properties, heat resistance, electrical properties, chemical resistance, etc. Widely used. In particular, PBT resins are widely used for wire harness connectors for automobiles because of their good properties and good dimensional accuracy in addition to the above-mentioned characteristics.

However, PBT resin has low impact resistance,
It has been pointed out that the molded product cracks when an impact is applied during assembly.In addition, as the connector itself becomes thinner, the strength of the thin parts called lances and hinges and the lock strength at the mating parts of the male and female connectors are increased. High rigidity is required. Further, as the performance of automobile equipment becomes higher, there is a possibility that the engine room and the like will be exposed to more severe high temperature conditions. For connector applications, it is necessary that the material satisfy these requirements in a well-balanced manner.

As a means for improving the impact resistance, a method of blending a polyester resin with a multilayer polyacrylate resin having a core-shell structure as a modifier is disclosed in Japanese Patent Application Laid-Open No. Sho.
Japanese Patent Publication No. 2-2898 and Japanese Unexamined Patent Application Publication No. Hei 8-2898 disclose a method of imparting excellent impact resistance by further blending an aromatic polycarbonate resin and a multilayer polyacrylate resin having a core-shell structure.
No. 59971.

Japanese Patent Publication No. 50391/1991 discloses a connector characterized by containing a polyalkylene oxide in a polyester resin. Also, a method of adding a polyester elastomer is widely used, and Japanese Patent Application Laid-Open No. 2-294357 discloses a method of improving the toughness and heat stability by containing a polyester elastomer and a bisoxazoline compound. Further, a modification method using an olefin-based resin (Japanese Unexamined Patent Publication No.
6554, JP-A-6-345949 and JP-A-9-296101) are also generally known.

On the other hand, it is known that a copolymer comprising ethylene and glycidyl methacrylate has a large effect of improving the impact resistance to a thermoplastic polyester resin, and further improves the hydrolyzability when used in combination with a polyfunctional compound. (JP-A-55-137154 and JP-B-5-62901) are disclosed.

In general, a method for reducing the terminal carboxyl group is effective as a method for improving the moist heat resistance. A method of solid-phase polymerization or a method of blending carbodiimide or polycarbodiimide (Japanese Patent Laid-Open No. 50-151953)
JP, JP-A-51-143054 and JP-A-60-228553), and a method of blending an epoxy compound (JP-B-61-42728, JP-A-61-27283).
1-4843, JP-A-5-209117,
JP-B-62-42941, JP-B-5-62903
JP, JP-B5-63505, JP-A-9-25
5853 and JP-A-9-263885) and a method of blending an oxazoline compound (JP-A-57-4961).
No. 6), but does not describe measures for impact resistance and rigidity.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin composition for a connector having both impact resistance, excellent hydrolysis resistance and high rigidity, and a molded article comprising the same.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have used a combination of an impact modifier comprising a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber and an epoxy compound. As a result, the present inventors have found that a resin composition having both high impact resistance and hydrolysis resistance and also having a high elastic modulus and suitable for a connector material can be obtained, and arrived at the present invention.

That is, the present invention relates to (A) a thermoplastic aromatic polyester resin having a terminal carboxyl group of 20 eq / ton or less.
00 parts by weight, (B) 1 to 20 parts by weight of an impact modifier comprising a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber, and (C) an epoxy compound 0.001
It is a resin composition for connectors comprising from 10 to 10 parts by weight.

The thermoplastic aromatic polyester resin (A) used in the present invention is a polyester containing an aromatic dicarboxylic acid as a main dicarboxylic acid component and an aliphatic diol having 2 to 10 carbon atoms as a main glycol component. Preferably, at least 80 mol%, more preferably at least 90 mol%, of the dicarboxylic acid component comprises the aromatic dicarboxylic acid component. The glycol component preferably comprises at least 80 mol%, more preferably at least 90 mol% of the glycol component of an aliphatic diol having 2 to 10 carbon atoms.

Preferred examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, methyl terephthalic acid, methyl isophthalic acid, and 2,6-naphthalene dicarboxylic acid. These can be used alone or in combination of two or more. Examples of the secondary dicarboxylic acid component other than the aromatic dicarboxylic acid include aliphatic or alicyclic dicarboxylic acids such as adipic acid, sebacic acid, decanedicarboxylic acid, azelaic acid, dodecanedicarboxylic acid, and cyclohexanedicarboxylic acid. .

Examples of the aliphatic diol having 2 to 10 carbon atoms include aliphatic diols such as ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol and the like, and fatty acids such as 1,4-cyclohexane dimethanol. A cyclic diol can be mentioned. One or more of these aliphatic diols and alicyclic diols can be used together. Examples of the secondary glycol component other than the aliphatic diol having 2 to 10 carbon atoms include p, p'-dihydroxyethoxybisphenol A and polyoxyethylene glycol.

Preferably, the main component of the thermoplastic aromatic polyester resin (A) is at least one dicarboxylic acid selected from the group consisting of terephthalic acid and 2,6-naphthalenedicarboxylic acid, and the main diol is a main diol. A thermoplastic aromatic polyester comprising an ester unit whose component is at least one diol selected from the group consisting of ethylene glycol, triethylene glycol and tetramethylene glycol.

Of these, polyesters having a repeating unit of tetramethylene terephthalate or tetramethylene-2,6-naphthalenedicarboxylate are more preferred, and the proportion of these repeating units in the total polyester is preferably at least 80 mol%, more preferably Preferably 9
0 mol% or more.

[0016] Thermoplastic aromatic polyester resin (A)
Has an intrinsic viscosity (dl / g) measured in orthochlorophenol of 35 ° C., preferably from 0.5 to 1.4, more preferably from 0.6 to 1.2. When the intrinsic viscosity is less than 0.5, the mechanical strength of the obtained composition is low, and thus it is not preferable. When the intrinsic viscosity is more than 1.4, the fluidity of the obtained composition is deteriorated.

The thermoplastic aromatic polyester resin (A) must have a terminal carboxyl group titrated with sodium hydroxide in benzyl alcohol at 35 ° C. not more than 20 eq / ton. If it exceeds 20 eq / ton, the effect of blocking the terminal carboxyl group by the epoxy compound is small.

The impact modifier (B) used in the present invention comprises:
It is composed of a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber.

The polyorganosiloxane rubber is a crosslinking agent for organosiloxane and polyorganosiloxane rubber,
Further, it can be obtained by emulsion polymerization of a graft crosslinking agent, if desired.

The polyalkyl (meth) acrylate rubber is prepared by adding an alkyl (meth) acrylate, a crosslinking agent for polyalkyl (meth) acrylate rubber and a graft-crosslinking agent for polyalkyl (meth) acrylate rubber in the presence of a polyorganosiloxane rubber latex. Obtained by emulsion polymerization.

According to this method, a crosslinked network in which the polyorganosiloxane rubber and the polyalkyl (meth) acrylate rubber are inseparably entangled with each other is formed. When a graft cross-linking agent is used during the polymerization of the polyorganosiloxane rubber, grafting of the polyalkyl (meth) acrylate rubber component to the polyorganosiloxane component also occurs, and in any case, both rubber components are substantially inseparable. A composite rubber is obtained.

As the organosiloxane used for preparing the polyorganosiloxane rubber, a cyclic organosiloxane having three or more member rings is used, and one having a three to six member ring is preferably used. Examples of such cyclic organosiloxanes include hexamethyltricyclosiloxane, octamethyltetracyclosiloxane, decamethylpentacyclosiloxane, dodecamethylhexacyclosiloxane, trimethyltriphenyltricyclosiloxane, tetramethyltetraphenyltetracyclosiloxane, octaphenyl Tetracyclosiloxane and the like can be mentioned,
These may be used alone or in combination of two or more.

The crosslinking agent used for preparing the polyorganosiloxane rubber may be trifunctional or tetrafunctional.
That is, trialkoxyalkylsilane, trialkoxyarylsilane, and tetraalkoxysilane are used.
Specific examples of such a crosslinking agent include trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetrabutoxysilane. As the crosslinking agent used in the present invention, tetraalkoxysilane is preferable, and tetraethoxysilane is particularly preferable.

The poly (organosiloxane rubber) does not react with the graft-crosslinking agent used for preparing the polyorganosiloxane rubber, and does not react when preparing the polyorganosiloxane rubber. It is a siloxane having a functional group that reacts during polymerization of (meth) acrylate rubber or graft polymerization. The following equation

[0025]

Embedded image

(In each formula, R ¹ represents a methyl group, an ethyl group, a propyl group or a phenyl group, R ² represents a hydrogen atom or a methyl group, n represents 0, 1 or 2, and p represents 1 to 1. And an integer of 6).

[0027] Among these compounds, (meth) acryloyloxyalkylsiloxane can form a graft chain efficiently. Specifically, β-methacryloyloxyethyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-
Examples thereof include methacryloyloxypropyldimethoxymethylsilane and γ-methacryloyloxydipropylethoxydiethoxysilane.

The component derived from the cyclic organosiloxane in the polyorganosiloxane rubber is preferably at least 60% by weight, more preferably at least 70% by weight, and the amount of the component derived from the crosslinking agent is preferably 0.1 to 10%. 30% by weight
And the amount of the component derived from the graft crosslinking agent is preferably 0 to 10% by weight.

The alkyl (meth) acrylate constituting the polyalkyl (meth) acrylate rubber includes alkyl acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate, and hexyl methacrylate, And alkyl methacrylates such as -ethylhexyl methacrylate and n-lauryl methacrylate, and preferably n-butyl acrylate.

As the crosslinking agent, a polyfunctional (meth) acrylate can be used, and ethylene glycol dimethacrylate, propylene glycol dimethacrylate,
Examples thereof include 3-butylene glycol dimethacrylate and allyl methacrylate.

As the graft crossing agent, 2 having different reactivities
A compound having a kind of unsaturated group is used, and examples of such a compound include allyl methacrylate, triallyl cyanurate and the like.

These crosslinking agents and graft-crossing agents can be used alone or in combination of two or more, and it is preferable that allyl methacrylate serves both. In the polyalkyl (meth) acrylate rubber component, the cross-linking agent and the graft cross-linking agent are preferably 0.1 to 10% by weight.

The impact modifier (B) in the present invention is a composite rubber comprising a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber, and the composite rubber is preferably 1 to 99% by weight of the polyorganosiloxane rubber and the polyalkyl. (Meth) acrylate rubber 99-1% by weight
And more preferably from 5 to 95% by weight of a polyorganosiloxane rubber and from 95 to 5% by weight of a polyalkyl (meth) acrylate rubber. When the content of the polyorganosiloxane rubber exceeds 99% by weight, the surface appearance of the obtained composition deteriorates, and when the content of the polyalkyl (meth) acrylate rubber exceeds 99% by weight, the impact resistance of the obtained composition becomes low, which is preferable. Absent.

Impact modifier (B) comprising a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber
Of the thermoplastic aromatic polyester resin (A) 1
1 to 20 parts by weight, preferably 2-1 to 100 parts by weight
0 parts by weight. If the amount is less than 1 part by weight, the effect of improving the impact by the impact modifier is small, and if it is more than 20 parts by weight, the mechanical properties deteriorate.

The epoxy compound (C) used in the present invention
Is a monofunctional, difunctional, trifunctional or polyfunctional epoxy compound. Among them, monofunctional and bifunctional epoxy compounds are preferred.

Examples of the epoxy compound (C) include methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, phenyl glycidyl ether, butyl phenyl glycidyl ether,
Glycidyl ethers such as allyl glycidyl ether;
Diglycidyl ethers such as neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, propylene glycol diglycidyl ether, bisphenol diglycidyl ether; fatty acid glycidyl esters such as glycidyl benzoate and sorbic acid; adipin Diglycidyl esters such as acid diglycidyl ester, terephthalic acid diglycidyl ester, and orthophthalic acid diglycidyl ester; and alicyclic diepoxy compounds such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate. Can be.

The amount of the epoxy compound (C) is 0.001 to 10 parts by weight, preferably 0.01 to 5 parts by weight, based on 100 parts by weight of the thermoplastic aromatic polyester resin (A). When the amount is less than 0.001 part by weight, the improvement of the hydrolyzability is small, and when it is more than 10 parts by weight, other mechanical properties are deteriorated.

The resin composition for a connector of the present invention preferably contains a ring-opening catalyst (D). Ring opening catalyst (D)
Quaternary ammonium salts, tertiary amines, imidazole compounds, alkali metal salts or alkaline earth metal salts or phosphonium salts, which are generally used as an epoxy ring-opening catalyst, can be used. Earth metal salts are preferred, and alkali metal salts of aliphatic carboxylic acids or alkaline earth metal salts of aliphatic carboxylic acids are particularly preferred.

Examples of the quaternary ammonium salt include triethylbenzylammonium chloride, tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride and the like.

Examples of the tertiary amine include dimethylbenzylamine, dimethylphenylamine, tributylamine, tris (dimethylamino) methylphenol and the like.

Examples of the imidazole compound include 2-methyl-4-ethylimidazole, 2-methylimidazole,
Examples thereof include 2-ethylimidazole.

Examples of the alkali metal salt or alkaline earth metal salt include sodium acetate, sodium caproate,
Sodium benzoate, sodium stearate, sodium ascorbate, sodium dihydrogen phosphate, calcium acetate, calcium benzoate, calcium formate, calcium oxalate, calcium phthalate, calcium terephthalate, calcium salicylate, calcium stearate, magnesium acetate, benzoate Examples thereof include magnesium phosphate, magnesium salicylate, magnesium terephthalate, and the like.

Examples of the alkali metal salt of an aliphatic carboxylic acid or the alkaline earth metal salt of an aliphatic carboxylic acid include sodium acetate, sodium caproate, sodium stearate and calcium stearate.

Examples of the phosphonium salt include tetramethylphosphonium bromide, tetrabutylphosphonium benzotriazolate, tetrabutylphosphonium bromide and the like.

When the epoxy ring-opening catalyst (D) is added, the addition amount is preferably 0.0001 to 100 parts by weight of the thermoplastic aromatic polyester resin (A).
5 parts by weight, more preferably 0.0001 to 1 part by weight. If the amount is less than 0.0001 part by weight, the catalytic effect is small, and if it is more than 5 parts by weight, the mechanical properties are adversely affected, which is not preferable.

It is preferable that a crystallization nucleating agent (E) is added to the resin composition for a connector of the present invention. As the crystallization nucleating agent (E), it is possible to use those generally used as nucleating agents such as inorganic compounds such as talc, calcium carbonate and titanium oxide; and organic compounds such as sodium carbonate and sodium montanate. it can.

When the crystallization nucleating agent (E) is added, the amount of the nucleating agent depends on the amount of the thermoplastic aromatic polyester resin (A).
It is preferably 0.0001 to 10 parts by weight, more preferably 0.001 to 5 parts by weight, based on 0 parts by weight. 0.
If it is less than 0001, the effect as a nucleating agent is small and crystallization cannot be sufficiently achieved. If the amount is more than 10 parts by weight, the mechanical properties are adversely affected, which is not preferable.

The resin composition for a connector of the present invention may be an inorganic solid such as calcium carbonate, titanium oxide, feldspar-based mineral, clay, white carbon, carbon black, glass beads, or the like as long as the object of the present invention is not impaired. Granular or amorphous filler; plate-like filler such as kaolin clay, talc, etc .; scale-like filler such as glass flake, mica, graphite; glass fiber, carbon fiber, wollastonite, potassium titanate, etc. A fibrous filler such as the following can be added. Also, antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, nucleating agents, plasticizers,
Additives such as a release agent, a pigment, and an impact modifier such as various elastomers may be further added.

The resin composition for a connector of the present invention can be produced by a method in which each component is simultaneously melt-kneaded using, for example, an extruder. Any of the components may be melt-kneaded in advance.

The resin composition for a connector obtained by melt-kneading with an extruder is usually cut into pellets by a pelletizer and then molded to give a molded product. The molding method may be any molding method such as injection molding or blow molding.

The connector resin composition of the present invention can be formed into a connector. The shape of the connector is not particularly limited. The connector can be used for automobiles, but can also be applied to switches, connectors, and various cases used in electric and electronic parts.

[0052]

According to the present invention, it is possible to provide a resin composition for a connector which has both high impact resistance and hydrolyzability, has a high elastic modulus, and is particularly suitable as a connector material.

[0053]

The present invention will be described in more detail with reference to the following examples.
In the examples, “parts” means “parts by weight”. Intrinsic viscosity was measured at 35 ° C. using an orthochlorophenol solvent. The terminal carboxyl group was titrated with sodium hydroxide in benzyl alcohol at 35 ° C. In addition, each test was evaluated according to the following method.

Impact strength: according to ASTM-D256. Flexural modulus: according to ASTM-D790. Terminal holding force: After inserting a terminal using a connector, the strength at the time of pulling out was measured by a pulling test at a speed of 50 mm / min using a tensile tester (Model TCM-100 manufactured by Japan Miniature Bearings Co., Ltd.) to measure the terminal holding force. . Hydrolysis resistance: 122 using ASTM 4 dumbbell pieces
After treating for 60 hours under moist heat conditions of 100 ° C. × 100% RH, a tensile tester (TCM manufactured by Japan Miniature Bearings Co., Ltd.)
(-100 type) at a speed of 50 mm / min to measure the tensile elongation.

[Examples 1 to 8 and Comparative Examples 1 to 6] Table 1
And a twin-screw extruder (TEX44:
Cylinder temperature of 260
The mixture was melt-kneaded at 50 ° C., a discharge rate of 50 kg / hr, and a rotation speed of 150 rpm, and the resin composition was pelletized by a cutter. Table 1 shows the composition of each of Examples 1 to 8, and Table 2 shows the composition of each of Comparative Examples 1 to 6. The extrudability of the examples and comparative examples was stable with almost no thread breakage. After the obtained chip was dried at 130 ° C. for 5 hours, the test piece for impact strength and flexural modulus was a 60-ton injection molding machine IS60B (manufactured by Toshiba), and the connector for measuring terminal holding force was a 40-ton injection molding machine PS40E (JP). Purification), the test piece for hydrolysis resistance measurement is a 75t injection molding machine IS75.
Various test pieces and connectors were molded using E (manufactured by Toshiba Corporation) at a melting temperature of 260 ° C. and a mold temperature of 60 ° C.

Using these test pieces and pellets, impact strength, flexural modulus, terminal holding power and hydrolysis resistance were evaluated. The results are shown in Tables 3 and 4.

[0057]

[Table 1]

[0058]

[Table 2]

[0059]

[Table 3]

[0060]

[Table 4]

In Example 1, 100 parts by weight of PBT resin was used as shown in Table 1.
2 parts by weight of the impact modifier comprising the organosiloxane rubber and the polyalkyl (meth) acrylate rubber described in Table 1, 1.5 parts by weight of the epoxy compound A described in Table 1 and Table 1
Is an example in which 0.05 parts by weight of the ring-opening catalyst described in 1) is blended.

In Example 2, 100 parts by weight of the PBT resin was used as shown in Table 1.
5 parts by weight of the organosilicate impact modifier described in Table 1,
Of the epoxy compound A described in Table 1 and 0.05 part by weight of the ring-opening catalyst described in Table 1.

Example 3 is an example in which the amount of the epoxy compound of Example 2 was changed to 1.5 parts by weight.

Example 4 is an example in which epoxy compound B was used in place of epoxy compound A of example 3.

Example 5 is an example using 1.0 part by weight of C shown in Table 1 as an epoxy compound.

In Example 6, a nucleating agent A was added to the composition of Example 3.
Is added in an amount of 0.5 part by weight.

Example 7 has the same composition as in Example 1 except that 10 parts by weight of the organosilicate impact modifier was used.

Example 8 is an example in which 5 parts by weight of a polyethylene terephthalate (PET) resin and 0.05 part by weight of a nucleating agent B were further added to the composition of Example 5.

On the other hand, Comparative Example 1 is an example using 100 parts by weight of the PBT resin.

Comparative Example 2 is an example in which 5 parts by weight of the organosilicate impact modifier shown in Table 1 was added to 100 parts by weight of the PBT resin.

In Comparative Example 3, 1.5 parts by weight of the epoxy compound A shown in Table 1 and 100 parts by weight of the PBT resin were used.
In this example, 0.05 part by weight of the ring-opening catalyst described in 1) was blended.

Comparative Example 4 is an example in which 1 part by weight of the organosilicate impact modifier shown in Table 1 was further added to the composition of Comparative Example 3.

Comparative Example 5 is an example in which 20 parts by weight of the organosilicate impact modifier shown in Table 1 was further added to the composition of Comparative Example 3.

In Comparative Example 6, 5 parts by weight of the organosilicate impact modifier shown in Table 1, 0.1 part by weight of the epoxy compound B shown in Table 1 and the ring-opening catalyst shown in Table 1 were added to 100 parts by weight of the PBT resin. Is an example in which 0.05 part by weight is blended.

In each of the examples, the impact resistance was improved as compared with Comparative Examples 1 and 3, and further, the hydrolysis resistance was improved as compared with Comparative Examples 1, 2 and 6. Further, as compared with Comparative Example 5, the flexural modulus and the terminal holding force were improved.

Claims (4)

[Claims] (A) The terminal carboxyl group is 20 eq / ton.
The following thermoplastic aromatic polyester resin 100 parts by weight,
(B) A resin composition for a connector comprising 1 to 20 parts by weight of an impact modifier comprising a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber and (C) 0.001 to 10 parts by weight of an epoxy compound. (A) The terminal carboxyl group is 20 eq / ton.
The resin composition for a connector according to claim 1, further comprising (D) 0.0001 to 5 parts by weight of a ring opening catalyst per 100 parts by weight of the following thermoplastic aromatic polyester resin. (A) The terminal carboxyl group is 20 eq / ton.
The resin composition for a connector according to claim 1, further comprising (E) a crystallization nucleating agent in an amount of 0.0001 to 10 parts by weight per 100 parts by weight of the following thermoplastic aromatic polyester resin. 4. A molded article comprising the connector resin composition according to claim 1.