JP2851965B2 - Flame retardant polyester resin composition with improved heat discoloration resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant polyester resin composition having improved heat discoloration resistance.

[0002]

2. Description of the Related Art Polyester resins represented by polyethylene terephthalate, polybutylene terephthalate and the like are widely used in electric and electronic equipment parts, automobile parts and the like because of their excellent properties. Particularly in the field of electric and electronic devices, in many cases, they are used by imparting flame retardancy in order to ensure safety against fire.

[0003] In order to impart flame retardancy to a polyester resin, an organic halogen compound and antimony trioxide are generally used in combination. However, in this combination, in addition to problems such as poor molding stability, exposure to high temperatures. However, there is a problem that the color is changed and the appearance is remarkably deteriorated.

Conventionally, in order to solve such a problem,
Numerous studies have been made, and specific compounding agents and oxygen blocking during compounding and kneading have been proposed, but no fundamental improvement has yet been made.

For example, JP-A-48-60141 proposes the use of an organic halogen compound of the following general formula (I) alone or in combination with antimony trioxide.
When used alone, it is difficult to pass the flame retardancy standards in the electric and electronic fields, and when used together, the molding stability deteriorates.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a flame-retardant polyester resin composition having improved heat discoloration resistance, good molding stability and excellent flame retardancy. The purpose is to do.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, by blending an organic halogen compound having a specific structure and an antimonate with a polyester resin, the heat resistance has been improved. The present inventors have found that a resin composition having improved discoloration, good molding stability, and excellent flame retardancy can be obtained, and the present invention has been achieved.

That is, the present invention provides the following components (A) to
A flame-retardant polyester resin composition having improved heat discoloration resistance, characterized by comprising (C) and a composition.

(A) 100 parts by weight of a polyester resin having an intrinsic viscosity of 0.3 to 1.5 dl / g (B) General formula (I)

Embedded image (Wherein X represents a halogen atom, R represents a lower alkyl group, n and n ′ each represent 1 to 5, and m and m ′ represent 0 or 1 to 4). 5 to 50 parts by weight (C) Antimonate 5 to 50 parts by weight

Hereinafter, the present invention will be described in detail. The polyester resin as the component (A) of the present invention is preferably obtained by condensation polymerization of a dicarboxylic acid component in which at least 40 mol% of the dicarboxylic acid component is terephthalic acid and a diol component.

The dicarboxylic acid components other than terephthalic acid include aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as azelaic acid, sebacic acid, adipic acid and dodecanedicarboxylic acid; isophthalic acid, naphthalenedicarboxylic acid, diphenyl-4, Examples thereof include aromatic dicarboxylic acids such as 4'-dicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and these may be used alone or in a mixture thereof.

On the other hand, the diol component has 2 to 2 carbon atoms.
20 aliphatic glycols, namely ethylene glycol, propylene glycol, 1,4-butanediol,
Examples thereof include aliphatic diols such as neopentylene glycol, 1,5-pentanediol, and decamethylene glycol; alicyclic diols such as cyclohexanedimethanol; and long-chain glycols having a molecular weight of 400 to 6000, ie, polyethylene glycol.

Typical polyester resins (A) used in the present invention include polyethylene terephthalate, polybutylene terephthalate and polycyclohexane dimethylene terephthalate.

The degree of polymerization of these polyester resins (A) is such that the intrinsic viscosity measured at 30 ° C. in a mixed solvent of phenol and tetrachloroethane at a weight ratio of 1: 1 is 0.3 to 1.5.
dl / g, preferably 0.4 to 1.2 dl / g.
If it is less than 0.3 dl / g, the physical properties expected as a resin will not be achieved, and if it exceeds 1.5 dl / g, the fluidity will be extremely poor, and injection molding will be practically difficult.

The structure of the organic halogen compound as the component (B) is shown by the general formula (I).

Embedded image Here, X represents a halogen atom, and its type is preferably bromine and chlorine, and particularly preferably bromine. R represents a lower alkyl group such as a methyl group, an ethyl group or a butyl group, and a methyl group is particularly preferable.

The organic halogen compound has a halogen content of 30 to 75% by weight, preferably 40 to 73% by weight.
Particularly preferably, it is 50 to 70% by weight.

The compounding amount of the organic halogen compound having the specific structure is 5 to 50 parts by weight, preferably 7 to 40 parts by weight, based on 100 parts by weight of the polyester resin. If it is less than 5 parts by weight, the flame retardancy may not be sufficient, and if it exceeds 50 parts by weight, the mechanical strength may not be able to maintain a practical level.

The component (C) used in the present invention is an antimonate, such as sodium hexahydrooxoantimonate (V), Na [Sb (OH) ₆ ].

The compounding amount of the antimonate is 5 to 50 parts by weight, preferably 7 to 100 parts by weight of the polyester resin.
４０40 parts by weight. If it is less than 5 parts by weight, the flame retardancy may not be sufficient, and if it exceeds 50 parts by weight, the mechanical strength may not be able to maintain a practical level.

In the composition of the present invention, it is preferable to incorporate a reinforcing filler as the component (D). The reinforcing filler is a fibrous, whisker-like, granular or powdery organic or inorganic substance. Examples of the fibrous reinforcing filler include glass fiber, alumina fiber, silicon carbide fiber,
Ceramic fibers, asbestos fibers, stainless steel fibers, boron fibers, carbon fibers, Kevlar (trade name: manufactured by DuPont, polyparaphenylene terephthalamide) fibers and the like.

Examples of whiskers include potassium titanate whiskers, aluminum borate whiskers,
Zinc oxide whiskers and the like can be mentioned.

Examples of granular or powdery reinforcing fillers include wollastonite, sericite, kaolin, mica,
Silicates such as clay, bentonite, asbestos, talc and alumina silicate; metal oxides such as alumina, silicon oxide, magnesium oxide, zirconium oxide and titanium oxide; carbonates such as calcium carbonate, magnesium carbonate and dolomite; calcium sulfate; Sulfates such as barium sulfate; and other examples include glass beads, glass flakes, boron nitride, and silicon carbide.

One or more of these reinforcing fillers are used, and if necessary, may be pretreated with a silane-based or titanium-based coupling agent.

The amount of these reinforcing fillers is from 0 to 250 parts by weight, preferably from 0 to 200 parts by weight, based on 100 parts by weight of the polyester resin. If it exceeds 250 parts by weight, the fluidity at the time of molding is poor, and it is not practical.

The composition of the present invention contains an antioxidant, a heat stabilizer, an ultraviolet absorber, and the like as long as the object of the present invention is not impaired.
A plasticizer, a crystal nucleating agent, a crystallization accelerator, a pigment, a colorant, an antistatic agent and the like can be blended.

The flame-retardant resin composition of the present invention can be easily produced by a usual melt-kneading method.

The present invention will be specifically described below with reference to examples.

Examples 1 to 6 and Comparative Examples 1 to 4 Polyester resin (A), organic halogen compound (B) and sodium antimonate (C), reinforcing filler (D), and brominated polystyrene and trioxide for comparison. Antimony was blended in the ratio shown in Table 1, melt-kneaded with a 40 mm diameter single screw extruder, and pelletized to obtain flame-retardant resin compositions of Examples 1 to 6 and Comparative Examples 1 to 4, respectively.

After the obtained pellets were dried at 130 ° C. for 5 hours, test pieces were molded at a mold temperature of 80 ° C. using a 5-ounce (142 g) injection molding machine.

The flame retardancy was tested at a thickness of 1/32 inch (0.794 mm) based on the UL-94 standard.

Regarding the heat discoloration resistance, the temperature was kept constant at 170 ° C. in a geared oven, the test piece was put in, taken out after 100 hours, and the hue change was measured with a color machine.

Regarding the molding stability, JIS K 72
Based on the melt flow rate measurement method specified in 10,
The residence time of the resin in the cylinder is 0 minutes (untreated), 10
And the melt flow rate was measured for 20 minutes.

The results are shown in Table 1.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

As described above, the flame-retardant polyester resin composition of the present invention has extremely excellent flame retardancy.
In addition, as compared with conventional products, the heat discoloration resistance is improved, and good molding stability is obtained.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiromi Kawachi 92 Minooki-machi, Fukuyama-shi, Hiroshima Manac Co., Ltd. Inside the Minoki Plant (72) Inventor Kiyoshi Mishima 92-Minoki-cho, Fukuyama-shi, Hiroshima Manac Co., Ltd. (56) References JP-A-48-60141 (JP, A) JP-A-64-38466 (JP, A) JP-A-50-91641 (JP, A) (58) Fields investigated (Int. ⁶ , DB name) C08L 67/02-67/04

Claims (1)

(57) [Claims] 1. A flame-retardant polyester resin composition having improved heat discoloration resistance, comprising the following components (A) to (C) and a composition. (A) 100 parts by weight of a polyester resin having an intrinsic viscosity of 0.3 to 1.5 dl / g (B) General formula (I) (Wherein, X represents a halogen atom, R represents a lower alkyl group, n and n ′ each represent 1 to 5, and m and m ′ represent 0 or 1 to 4). 5 to 50 parts by weight (C) Antimonate 5 to 50 parts by weight