JPH11106615A - Flame retardant polyester resin composition for low gas evolving and contact-having electrical and electronic part and contact-having electronic part made therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low gas-evolving and flame-retardant polyester resin composition. SOLUTION: This flame retardant polyester resin composition is obtained by compounding (a) 100 pts.wt. of a thermoplastic aromatic polyester with (b) 2.0-50.0 pts.wt. of a halogen-containing acrylic resin obtained by polymerizing a halogen-containing benzyl acrylate and/or benzyl methacrylate expressed by the formula [X is a halogen atom; (n) is an integer of 1-5; Z is a hydrogen atom or methyl] as a flame retardant, (c) 1-20 pts.wt. of a flame-retardant auxiliary (d) 5-100 pts.wt. of a glass fiber and (e) 0.01-5.0 pts.wt. of a transesterification inhibitor, wherein, the content of the flame retardant is <=40.0 wt %, based on the whole weight of this composition and the quantity of a gas evolved when the powder obtained by freeze-grinding of this composition to a particle size of <=200 μm is heated at 150 deg.C for 1 h is <=10 ppm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stable polyester composition which generates a small amount of gas when used at high temperature or for a long period of time and has a small amount of sublimate during melt processing.

[0002]

2. Description of the Related Art Polyethylene terephthalate (hereinafter, PE)
Thermoplastic aromatic polyester resins represented by T) and polybutylene terephthalate (hereinafter sometimes abbreviated as PBT) have excellent mechanical strength, chemical resistance and electrical insulation. Widely used for electric, electronic parts, automobile parts and other mechanical parts.

[0003]

However, as a problem in the molding process of these polyesters, when heated in a molten state, a decomposition gas or a sublimate of a resin is generated. Voids may form and adhere to the mold, causing contamination and corrosion.

Further, when a molded article using these polyesters is used at a high temperature of about 100 ° C. or higher, decomposition gas such as tetrahydrofuran is generated, and electricity or electric power of relays, switches, connectors and the like is generated. In electronic components, it also causes the metal contacts to become contaminated or corroded.

[0005] In order to solve this problem, a molding material (composition comprising PBT and an additive) free of generation of decomposition gas and sublimate is required.

Further, there is a demand for so-called light and thin electronic parts. In order to meet the demand, a molding material which exhibits high fluidity at the time of melting is required, and the molding material must be capable of meeting the demand for recycling.

[0007] In general, by reducing or eliminating volatile components derived from additives other than the main component of polybutylene terephthalate by carefully selecting the components (materials), it is possible to reduce the gasification of molded products during melt molding. This is possible to some extent, and previous considerations have been in this regard.

However, the most important matter is how to reduce the gas derived from polybutylene terephthalate. Few have mentioned this technology.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to provide a polyester resin composition for electric and electronic parts in which decomposition gas and sublimate which cause poor contact at the contact portion and mold corrosion are extremely small. To provide an electric and electronic component comprising the composition.

[0010]

Means for Solving the Problems In order to solve the above problems, the present inventors have made intensive studies. As a result, it has been found that the above problem can be solved by a composition using a specific halogenated acrylic resin as a flame retardant in a thermoplastic polyester resin.

An object of the present invention is to provide a flame-retardant polyester resin composition for electric and electronic parts, which has very little decomposition gas and sublimate which cause poor contact at the contact portion and mold corrosion, and an electric and electronic part comprising the same. The object is achieved by the following configurations.

That is, the present invention relates to (a) 100 parts by weight of a thermoplastic aromatic polyester, and (b) a flame retardant represented by the following general formula (1):

[0013]

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Wherein X is a halogen atom, n is an integer of 1 to 5, and Z is a hydrogen atom or a methyl group.
Or 2.0 to 50.0 parts by weight of a halogen-containing acrylic resin obtained by polymerizing benzyl methacrylate; (c) 1 to 20 parts by weight of a flame retardant aid; (d) 5 to 100 parts by weight of glass fiber; A flame retardant polyester resin composition comprising 0.01 to 5.0 parts by weight of a flame retardant, wherein the content of the flame retardant is 5 to 40 based on the whole composition.
% By weight, and has a low gas property of 10 ppm or less when heated at 150 ° C. for 1 hour to powder having a particle size of 200 μm or less by freeze-pulverization. It is a polyester resin composition.

Hereinafter, the present invention will be described in detail. The thermoplastic aromatic polyester used in the present invention is an aromatic polyester comprising terephthalic acid and / or isophthalic acid as an acid component and at least one aliphatic diol such as ethylene glycol, trimethylene glycol, tetramethylene glycol or the like as a diol component. Group polyester.

Of these, polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate are preferred.

The thermoplastic aromatic polyester may be one obtained by substituting a part of the above polyester with a copolymer component. Such copolymerization components include phthalic acid; alkyl-substituted phthalic acid such as methyl terephthalic acid and methyl isophthalic acid; naphthalene such as 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, and 1,5-naphthalene dicarboxylic acid Dicarboxylic acids; diphenyldicarboxylic acids such as 4,4'-diphenyldicarboxylic acid and 3,4'-diphenyldicarboxylic acid; aromatic dicarboxylic acids such as diphenoxyethanedicarboxylic acids such as 4,4'-diphenoxyethanedicarboxylic acid; Succinic acid, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, aliphatic or alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid,
Alicyclic diols such as 1,4-cyclohexanedimethanol, dihydroxybenzenes such as hydroquinone and resorcin; 2,2'-bis (4-hydroxyphenyl) propane, 2,2'-bis (4-hydroxyphenyl) sulfone Bisphenols such as ether diols obtained from bisphenols and glycols such as ethylene glycol; and oxycarboxylic acids such as ε-oxycaproic acid, hydroxybenzoic acid, and hydroxyethoxybenzoic acid.

Further, the aromatic polyester described above may have, as a branching component, an acid having a polyfunctional ester forming ability such as trimesic acid or trimellitic acid or a polyfunctional ester forming ability such as glycerin, trimethylolpropane or pentaerythritol. The alcohol may be copolymerized at a ratio of 1.0 mol% or less, preferably 0.5 mol% or less, more preferably 0.3 mol% or less.

The thermoplastic aromatic polyester used in the present invention has an intrinsic viscosity of 0.4 to 1.2. If it is less than 0.4, sufficient properties cannot be obtained, and if it is more than 1.2, the melt viscosity is high, the fluidity is reduced, and the moldability is impaired. Here, the intrinsic viscosity is measured at 35 ° C. using o-chlorophenol as a solvent.

The above-mentioned thermoplastic aromatic polyester can be produced by a usual production method, for example, a melt polycondensation reaction or a method combining this with a solid phase polymerization reaction. For example, an example of the production of polyethylene terephthalate will be described. Terephthalic acid or an ester-forming derivative thereof (for example, a lower alkyl ester such as dimethyl ester or monomethyl ester) and ethylene glycol or an ester-forming derivative thereof are heated in the presence of a catalyst. After the reaction, the resulting glycol ester of terephthalic acid is polymerized to a predetermined polymerization degree in the presence of a catalyst.

The halogen-containing acrylic resin of the component (b) is obtained by homopolymerizing benzyl acrylate and / or benzyl methacrylate containing halogen represented by the following formula (1), two or more copolymers, Is a copolymer with a vinyl monomer.

[0022]

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Examples of the benzyl acrylate containing a halogen include pentabromobenzyl acrylate, tetrabromobenzyl acrylate, tribromobenzyl acrylate, pentachlorobenzyl acrylate, tetrachlorobenzyl acrylate, and trichlorobenzyl acrylate. Examples of the halogen-containing benzyl methacrylate include methacrylates corresponding to the acrylates described above. These can be used as a mixture.

When the halogen-containing acrylic resin is a copolymer with another vinyl-based monomer, the vinyl-based monomer used for copolymerizing with the halogen-containing benzyl acrylate and / or benzyl methacrylate includes acrylic acid, Acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, methacrylic acid,
Examples include methacrylates such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and benzyl methacrylate; unsaturated carboxylic acids such as styrene, acrylonitrile, fumaric acid, and maleic acid or anhydrides thereof; vinyl acetate; and vinyl chloride. These can be used usually in an equimolar amount or less, preferably in an amount of 0.5 mol or less based on benzyl acrylate containing halogen.

When a crosslinkable vinyl monomer is used as the vinyl monomer, xylene diacrylate, xylene dimethacrylate, tetrabromoxylene diacrylate, tetrabromoxylene dimethacrylate, butadiene, isoprene, divinylbenzene and the like are used. These can be used in an amount of 0.5 times or less of benzyl acrylate or benzyl methacrylate which usually contains halogen.

The degree of polymerization of the halogen-containing acrylic resin is preferably about 10 to 60 from the viewpoint of extrudability and fluidity.

The halogen-containing acrylic resin desirably has a halogen content of 10% by weight or more, preferably 30% by weight or more, and more preferably about 50 to 70% by weight.

The blending amount of the halogen-containing acrylic resin with respect to 100 parts by weight of polybutylene terephthalate is from 0.5 to
50 parts by weight. The larger the amount of the inorganic filler in the entire composition, the smaller the amount of the inorganic filler. When a flame retardant auxiliary such as Sb ₂ O ₃ is used in combination, the amount of the inorganic filler can be reduced. Parts are necessary, and below that, the flame retardancy of the resulting composition is insufficient. Conversely, when the amount exceeds 50 parts by weight, the dispersibility of the flame retardant is poor, so that the extrudability and moldability are reduced, and the strength of the obtained molded product is also reduced.

As the flame retardant, the above-mentioned halogenated acrylic resin and another flame retardant can be used in combination. As these flame retardants, for example, general formula (2)

[0030]

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A bisphenol A-based epoxy resin containing a halogen represented by the formula: wherein X represents a halogen atom.

The total amount of the halogenated acrylic resin and the other flame retardant should be 5 to 40% by weight based on the whole composition. If the amount is less than 5% by weight, the flame retardancy of the obtained composition is insufficient. If the amount exceeds 40% by weight, the dispersibility of the flame retardant is poor. Will also be lower.

Further, a flame retardant aid can be added for the purpose of promoting the flame retardant effect. The (c) flame retardant aid functions to enhance the flame retardancy due to a synergistic effect with the (b) brominated flame retardant. Examples of suitable flame retardant agents, Sb ₂ O ₃ and / or _{x Na 2 O · Sb 2 O} 5 · y H 2 O (x = 0~1, y = 0~4) and the like. The particle size of the flame retardant aid is not particularly limited, but is preferably 0.02 to 5 µm. If desired, those surface-treated with an epoxy compound, a silane compound, an isocyanate compound, a titanate compound or the like can be used.

The compounding amount of the flame retardant is 0 to 70 parts by weight.
Preferably, it is 1 to 50 parts by weight. In order to effectively impart flame retardancy, it is preferable that the content is 20 to 70% by weight based on the flame retardant. If the compounding amount exceeds 70 parts by weight, decomposition of the resin and the compounding agent is promoted, and the characteristics of the molded product are undesirably deteriorated.

In the resin composition of the present invention, an inorganic filler, for example, a granular or amorphous filler such as calcium carbonate, titanium oxide, feldspar-based mineral, clay, white carbon, carbon black, glass beads, etc .; kaolin clay Flakes such as talc, talc, etc .; glass flakes,
A flaky filler such as mica and graphite; and a fibrous filler such as glass fiber, carbon fiber, wollastonite, potassium titanate and the like can be added.
From the viewpoint of mechanical strength and heat resistance, glass fiber is particularly preferable. The amount of the inorganic filler is 0 to 200 parts by weight based on 100 parts by weight of the thermoplastic aromatic polyester. Preferably, it is 5 to 150 parts by weight, more preferably 10 to 100 parts by weight.

As the (e) transesterification inhibitor used in the present invention, sodium dihydrogen phosphate, potassium acetate,
Trimethyl phosphate, phenylphosphonic acid and the like. From the viewpoint of low gas properties, sodium dihydrogen phosphate is particularly desirable. Sodium dihydrogen phosphate may be anhydrous or water of crystallization. The compounding amount of the transesterification inhibitor is based on 100 parts by weight of the thermoplastic aromatic polyester.
It is 0.01 to 5 parts by weight, preferably 0.05 to 1 part by weight.

The resin composition of the present invention contains additives such as a nucleating agent, a lubricant, an antioxidant, an ultraviolet absorber, a heat stabilizer, an antistatic agent, and a pigment as long as the object of the present invention is not impaired. I can do it.

The method for producing the resin composition of the present invention is not particularly limited, and a known method can be employed.
For example, 1) a method of mixing each component, kneading and extruding with an extruder to prepare pellets, and then forming the pellets, 2)
A method of once preparing pellets having different compositions, mixing the pellets in a predetermined amount and subjecting the mixture to molding to obtain a molded article having a desired composition after molding. 3) A method of directly charging one or more of each component to a molding machine. Any of the above can be applied. Mixing and adding a part of the resin component as a fine powder with other components is a preferable method for uniformly blending these components.

The flame-retardant PBT resin composition of the present invention is processed into various molded articles requiring flame retardancy.
In particular, when used for electric or electronic parts such as switches and relays having metal electric contacts, the effect is extremely large.

[0040]

The present invention will be described below in detail with reference to examples. still,
Parts in the examples mean parts by weight. The raw materials of the compositions used in the examples are as follows. The properties of the molded product were measured by the following methods.

1. Polymer: polybutylene terephthalate (PBT in the table) IV: 0.70 (Examples 1 and 2, Comparative Example 1) manufactured by Teijin Limited IV: 0.875 (Comparative Example 2) manufactured by Teijin Limited Br-based flame retardant: Brominated acrylic resin (Examples 1-2) FR-1025 manufactured by Bromchem Far East Co., Ltd. Brominated bisphenol A-based epoxy resin (Example 2, Comparative Example 1) Dainippon Ink and Chemicals, Inc. 2.) EP-100 brominated bisphenol A-based polycarbonate resin (Comparative Example 2) FG7100 manufactured by Teijin Chemicals Ltd. 3. Antimony flame retardant: PATOX-M (antimony trioxide in the table) manufactured by Nippon Seiko Co., Ltd. NA-1030 (sodium antimonate in the table) manufactured by Nissan Chemical Industries, Ltd. 4. Glass fiber: T-124 manufactured by Nippon Electric Glass Co., Ltd. Average fiber diameter 13 μm Transesterification inhibitor: sodium dihydrogen phosphate dihydrate (Examples 1 and 2) Potassium acetate manufactured by Wako Pure Chemical Industries, Ltd. (Comparative Example 1) Trimethyl phosphate manufactured by Wako Pure Chemical Industries, Ltd. (Comparative Example 2) ) Tokyo Chemical Industry Co., Ltd. Low gas evaluation: ASTM under certain conditions by injection molding
A tensile test piece was prepared, and this was freeze-ground to a particle size of 200 μm to obtain a sample. Take 0.6g sample, 22m
After leaving at 150 ° C. for 1 hour in a 1 headspace, the generated gas was measured by gas chromatography. The weight of the generated gas is expressed as p with respect to the weight of the sample.
pm.

The measurement conditions are shown below. Apparatus; Perkin Elmer HS-40XL, HP6890 column; TC1701, 60 mm, IP = 0.25 mm,
If = 0.25 μm Temperature rising condition; 50 ° C. (2 minutes) → 10 ° C./min. → 28
0 ° C (10 minutes) Detector; FID

[Examples 1 and 2 and Comparative Examples 1 and 2] Various components shown in Table 1 were added to polybutylene terephthalate and mixed, and then a pellet-shaped composition was prepared using an extruder. Next, the above-mentioned evaluation was performed using this pellet.
Table 2 shows the results.

Further, a molded product of a relay case was prepared from the pellet by injection molding, and the above evaluation was performed. Table 3 shows the results.

For comparison, a flame retardant which does not fall under the requirements of the present invention as a component (b); a brominated epoxy or brominated polycarbonate alone was tested and evaluated in the same manner as in the examples. The results are shown in Tables 1 to 3.

Table 2 shows that the flame-retardant polyester resin composition of the present invention has excellent low gas properties.
Table 3 shows that the molded article made of the flame-retardant polyester resin composition of the present invention also has excellent low gas properties.

[0047]

[Table 1]

[0048]

[Table 2]

[0049]

[Table 3]

[0050]

According to the present invention, there are provided a flame-retardant polyester resin composition and an electric / electronic component which generate less gas.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 33:16)

Claims (3)

[Claims] (A) a thermoplastic aromatic polyester 100
(B) As a flame retardant, a general formula (1) [Wherein, X is a halogen atom, n is an integer of 1 to 5, Z represents a hydrogen atom or a methyl group] Halogen-containing acrylic obtained by polymerizing a halogen-containing benzyl acrylate and / or benzyl methacrylate represented by the formula: 2.0 to 50.0 parts by weight of resin (c) 1 to 20 parts by weight of flame retardant aid (d) 5 to 100 parts by weight of glass fiber (e) 0.01 to 5.0 parts by weight of transesterification inhibitor A flame-retardant polyester resin composition having a flame retardant content of 5 to 40 based on the entire composition.
% By weight, and has a low gas property of 10 ppm or less when heated for 1 hour at a temperature of 150 ° C for a powder crushed to a particle size of 200 μm or less by freeze grinding. Polyester resin composition. 2. The flame-retardant polyester resin composition for contactable electric / electronic parts according to claim 1, wherein the transesterification inhibitor is sodium dihydrogen phosphate. 3. A flame-retardant polyester resin composition according to claim 1 or 2, which is obtained by molding by injection molding.
The temperature of the powder pulverized to a particle size of 200 μm or less
Gas generated when heated at 150 ° C for 1 hour is 60p
pm or less contacted electric and electronic parts.