JPH07133407A - Wholly aromatic polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain a composition having high flame retardance without impairing characteristics of polyester itself and excellent in mechanical strength, heat resistance and chemical resistance by blending a wholly aromatic polyester with red phosphorus. CONSTITUTION:This composition is obtained by blending 100 pts.wt. of a wholly aromatic polyester with 0.05-5 pts.wt. of red phosphorus. As the red phosphorus to be blended, e.g. red phosphorus treated with aluminum hydroxide to suppress its oxidation or coated with paraffin, etc., or red phosphorus mixed with trioxane to stabilize the red phosphorus is used. Polypropylene, rubber, etc., may be added to the composition.

Description

Detailed Description of the Invention

[0001]

The present invention has a high degree of flame retardancy,
The present invention relates to a wholly aromatic polyester resin composition having excellent mechanical strength, heat resistance, chemical resistance and the like.

[0002]

2. Description of the Related Art Wholly aromatic polyester has excellent mechanical strength, heat resistance, and chemical resistance. For example, it is used as an injection-molded product in automobiles, electric / electronic devices, machinery, and all other fields of industry. Is used for.

Specific examples of wholly aromatic polyesters include:
Non-liquid crystalline compounds (for example, those consisting of 2,2-bis (4'-hydroxyphenyl) propane residue, terephthalic acid residue and isophthalic acid residue disclosed in JP-B-55-4771) There is a so-called liquid crystalline one that exhibits optical anisotropy in the molten state, but since the liquid crystalline wholly aromatic polyester exhibits particularly excellent mechanical strength, heat resistance, and chemical resistance, it has been particularly noted in recent years. Are gathering. Specific examples of such a liquid crystalline wholly aromatic polyester include those disclosed in JP-A-54-7.
A compound comprising a residue of p-hydroxybenzoic acid and a residue of 6-hydroxy-2-naphthoic acid disclosed in Japanese Patent No. 7691, and a residue of phenylhydroquinone disclosed in Japanese Patent Laid-Open No. 53-65421. A residue of terephthalic acid, a residue of p-hydroxybenzoic acid, a residue of 4,4'-diphenyldicarboxylic acid, a residue of terephthalic acid and hydroquinone disclosed in JP-A-58-91721. And the residue disclosed in JP-A-1-294732.
-Residue of hydroxybenzoic acid, residue of 4,4'-dihydroxydiphenyl, residue of terephthalic acid and residue of 2,6-naphthalenedicarboxylic acid, JP-A-3-1521
A residue of p-hydroxybenzoic acid disclosed in Japanese Patent No. 23,
Examples thereof include those comprising a residue of 4,4'-dihydroxydiphenyl and a residue of terephthalic acid.

The wholly aromatic polyester has excellent mechanical strength, heat resistance and chemical resistance, and is also flame retardant in general engineering plastics (for example, polycarbonate,
It is superior to polybutylene terephthalate, polyacetal, nylon, etc.). However, in recent years, there have been extremely strict requirements for flame retardancy of molded products in the field of electric and electronic devices, and wholly aromatic polyesters have not always been able to satisfy such requirements. In the electrical and electronic equipment field, various parts are becoming smaller and smaller, and for example, the thickness of molded products forming connectors and coil bobbins is about 0.4 mm. In such an extremely thin-walled molded product, even if it is a wholly aromatic polyester, the flame-retardant property is insufficient such that the burning time becomes long in the burning test.

Little attempts have been made to improve the flame retardancy of such wholly aromatic polyesters. The reason is that the wholly aromatic polyester requires high molding processing temperature because of its high heat resistance, and even if a conventional general halogen-based flame retardant is blended, due to decomposition of the flame retardant during molding, The deterioration may occur and the original excellent properties of the wholly aromatic polyester may be impaired.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to provide a resin composition in which flame retardancy is imparted to a wholly aromatic polyester without impairing its excellent properties.

[0007]

The present invention is intended to solve the above-mentioned problems, and its gist is to provide a wholly aromatic polyester 100
A wholly aromatic polyester resin composition is characterized in that 0.05 to 5 parts by weight of red phosphorus is blended with respect to parts by weight.

The present invention will be described in detail below. The wholly aromatic polyester of the present invention is composed of a unit composed of a residue of an aromatic hydroxycarboxylic acid and / or a residue of an aromatic diol and a residue of an aromatic dicarboxylic acid.

Aromatic hydroxycarboxylic acids have a hydroxyl group and a carboxyl group bonded to an aromatic ring, and specific examples thereof include p-hydroxybenzoic acid, m-hydroxybenzoic acid, 6-hydroxy-carboxylic acid. 2-
Examples thereof include naphthoic acid, 6-hydroxy-1-naphthoic acid, 3-methyl-4-hydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid and 3-methoxy-4-hydroxybenzoic acid. Among them, p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are the most common.

The aromatic diol has two hydroxyl groups bonded to the aromatic ring, and specific examples thereof include hydroquinone, resorcin and 4,4'-.
Dihydroxydiphenyl, 2,6-naphthalenediol,
4,4'-dihydroxydiphenyl ether, bis (4-
Hydroxyphenoxy) ethane, 3,3'-dihydroxydiphenyl, 3,3'-dihydroxydiphenyl ether, 1,6-naphthalenediol, 2,2-bis (4'-hydroxyphenyl) propane, 2,2-bis (4 ' -Hydroxyphenyl) methane, chlorohydroquinone, methylhydroquinone, t-butylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4-chlororesorcin, 4-methylresorcin and the like. Among them, hydroquinone and its nuclear substitution product, 4,4'-dihydroxydiphenyl and
2,6-naphthalene diol is the most common.

Further, the aromatic dicarboxylic acid has two carboxyl groups bonded to the aromatic ring,
Specific examples include terephthalic acid, isophthalic acid, 4,
4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, diphenylether-4,4'-dicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenoxybutane-4 , 4 '
-Dicarboxylic acid, diphenylethane-4,4'-dicarboxylic acid, diphenylether-3,3'-dicarboxylic acid, diphenoxyether-3,3'-dicarboxylic acid, diphenylethane-3,3'-dicarboxylic acid, chlorterephthalate Acid, dichloroterephthalic acid, bromterephthalic acid, methylterephthalic acid, dimethylterephthalic acid, ethylterephthalic acid, methoxyterephthalic acid, ethoxyterephthalic acid and the like can be mentioned. Of these, terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid and 2,6-naphthalenedicarboxylic acid are the most common.

The wholly aromatic polyester in the present invention is
It can be produced from an aromatic hydroxycarboxylic acid, an aromatic diol, an aromatic dicarboxylic acid or their derivatives, which are the constituent units, by a known polycondensation reaction. For example, (1) stir acetylated aromatic hydroxycarboxylic acid and / or acetylated aromatic diol and aromatic dicarboxylic acid at high temperature, preferably under reduced pressure to increase the degree of polymerization while removing acetic acid. , A method for obtaining a wholly aromatic polyester, (2) phenyl ester of aromatic hydroxycarboxylic acid and / or phenyl ester of aromatic diol and aromatic dicarboxylic acid are stirred at high temperature, preferably under reduced pressure to remove phenol. However, there is a method of increasing the degree of polymerization to obtain a wholly aromatic polyester. It is also possible to use an unacetylated starting material, add an acetylating agent such as acetic anhydride during the reaction to acetylate the hydroxyl group, and then carry out the production according to the method (1). It is also possible to add an inert heat-resistant plasticizer such as diphenyl ether or diphenyl sulfone to the reaction system in order to reduce the melt viscosity during production and accelerate the reaction.

The polycondensation reaction is usually carried out at a temperature of 150 to 400 ° C. and a pressure of atmospheric pressure to 0.01 torr. In the polycondensation, it is possible to use a general polymerization condensation catalyst. Examples of the polymerization condensation catalyst include tin compounds such as stannous acetate, zinc compounds such as zinc acetate, and antimony compounds such as antimony trioxide.

The degree of polymerization of the wholly aromatic polyester in the present invention is not particularly limited, and the degree of polymerization can be appropriately selected according to the purpose.

In the present invention, red phosphorus can be blended with the wholly aromatic polyester without any treatment, but red phosphorus may be ignited during storage or gradually dissolved in water. However, since the pH of water may be lowered, it is desirable to use treated red phosphorus in order to solve these problems. As a specific example of such treatment, a method of catalytically suppressing the oxidation of red phosphorus by adding a small amount of aluminum hydroxide or magnesium hydroxide to red phosphorus, coating red phosphorus with paraffin or wax,
Method of suppressing contact with water, method of stabilizing by mixing with ε-caprolactam or trioxane, stabilization by coating with a thermosetting resin such as phenol-based, melamine-based, epoxy-based, unsaturated polyester-based A method of treating red phosphorus with an aqueous solution of a metal salt such as copper, nickel, silver and iron to precipitate the metal phosphide on the surface of red phosphorus and stabilizing it with aluminum hydroxide or zinc hydroxide. There is a coating method or a combination of these methods.

The compounding amount of red phosphorus is a wholly aromatic polyester.
It is necessary to add 0.05 to 5 parts by weight to 100 parts by weight. If the blending amount of red phosphorus is small, the flame retarding effect is insufficient. Conversely, if it is too large, the flame retarding effect is remarkable, but various mechanical properties such as strength and elastic modulus of the resin composition and thermal A decrease in stability is observed, which is not preferable.

The method of adding red phosphorus to the wholly aromatic polyester is arbitrary. For example, red phosphorus may be directly blended, or red phosphorus is previously blended with another polymer containing a wholly aromatic polyester in a high concentration to produce a red phosphorus-containing master pellet, which is blended with the wholly aromatic polyester. May be.

In the resin composition of the present invention, other polymers may be further blended, if necessary, as long as the characteristics are not significantly impaired. In this case, the blending amount is preferably 30 parts by weight or less with respect to 100 parts by weight of wholly aromatic polyester. Such other polymers include p-
Semi-aromatic liquid crystal polyester composed of a hydroxybenzoic acid residue unit and ethylene terephthalate unit, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polycaprolactone, nylon 6, nylon 66, nylon 46, amorphous nylon, polysulfone , Polyethersulfone, polyetherketone, polyetheretherketone, polyetherimide, polyphenylene oxide, polyphenylene sulfide, ABS, PMMA, polypropylene, polyethylene, phenoxy resin, rubber and the like.

Furthermore, in the resin composition of the present invention, if necessary, a pigment, a heat stabilizer, an antioxidant, a weathering agent, a reinforcing material,
It is possible to add a release agent or the like. As the reinforcing material, glass fiber, metal fiber, potassium titanate whiskers,
There are fibrous reinforcements such as carbon fibers, filler-based reinforcements such as talc, calcium carbonate, mica, glass flakes, metal flakes. In particular, glass fibers having a diameter of 3 to 20 μm are preferable because they stabilize the melt viscosity of the resin composition and further improve its strength, elastic modulus and heat resistance.

The resin composition of the present invention has excellent flame retardancy, mechanical strength, heat resistance, chemical resistance, etc.
It is expected to find applications in all fields of industry, including electrical and electronic equipment and machinery.

[0021]

In the present invention, by using red phosphorus as the flame retardant, a high degree of flame retardation can be realized with a remarkably small blending amount as compared with the conventional halogen-based flame retardant. Although the reason why such a remarkable effect is exerted is not clear, it is presumed to be related to the structural characteristic of the wholly aromatic polyester, that is, the inclusion of the aromatic ring in a high concentration. It is presumed that the wholly aromatic polyester having such a structure is carbonized in an extremely short time due to the interaction with red phosphorus at a high temperature, and as a result, such a remarkable flame retardant effect is exhibited.

[0022]

EXAMPLES The present invention will be specifically described below with reference to examples. The measuring methods in Examples and Comparative Examples are as follows. (1) Flexural strength and flexural modulus Based on ASTM D790, a test piece having a thickness of 1.6 mm was measured. (2) Izod impact strength Based on ASTM D256, it was measured with a notched test piece having a thickness of 3.2 mm. (3) Heat distortion temperature Based on ASTM D648, the load was measured at 1.8 MPa. (4) Flame retardance Underwriters Laboratories flame retardancy test method, UL
Based on 94, the combustion test was performed by changing the dimensions of the test piece only to 0.4 mm in thickness, 12 mm in width and 30 mm in length. That is,
The test piece was exposed to the flame for 10 seconds, and the burning time after removing the flame was measured.

Example 1 A polymerization vessel equipped with a stirrer, a nitrogen inlet tube and a condenser was connected with p-
Charge 675 g (3.75 mol) of acetoxybenzoic acid and 287 g (1.25 mol) of 6-acetoxy-2-naphthoic acid, and evacuate the system with nitrogen three times to purge the internal temperature to 250 ° C. Dissolved. Acetic acid was distilled off from the polymerization vessel while stirring the contents at this temperature for 3 hours. Then, set the internal temperature to 280
The temperature was raised to ℃ and kept at this temperature for 1.5 hours, and further the final polymerization temperature was raised to 320 ℃ and kept for 30 minutes. Then, gradually reduce the pressure while maintaining the final polymerization temperature, finally to 0.1 torr,
The reaction was further performed for 1 hour. After that, the contents were discharged from a nozzle below the polymerization can and finely cut to obtain pellets. The resulting wholly aromatic polyester (PAR-1
Has a melting point of 300 ° C. by DSC measurement. To 100 parts by weight of the obtained pellets, 0.5 parts by weight of "NOVARED" (manufactured by Rin Kagaku Co., surface treated red phosphorus, content of red phosphorus of 90% by weight or more) and chopped glass fibers (T277, manufactured by Denki Kagaku Co., Ltd.) 43 parts by weight was mixed with each other and compounded at 320 ° C. using a small kneading device (Labo Plastomill, manufactured by Toyo Seiki Co., Ltd.). The pellets thus obtained were molded at 320 ° C. using a small injection molding machine (HI-TECH 10/60, manufactured by Butler Co.) to obtain various test pieces. Table 1 shows the results of various performance evaluations using the obtained test pieces.

Example 2 Various performance evaluations were performed in the same manner as in Example 1 except that the compounding amount of "Novared" was 2 parts by weight. The results are shown in Table 1.

Comparative Example 1 Various performance evaluations were performed in the same manner as in Example 1 except that "Novarred" was not added. The results are shown in Table 1.

Comparative Example 2 5 parts by weight of "Pyrocheck 68PB" (manufactured by Nissan Fellow, brominated polystyrene, bromine content 68% by weight) was used in place of 0.5 part by weight of "NOVARED", and the amount of chopped glass fiber was changed. Various performances were evaluated in the same manner as in Example 1 except that the amount was 45 parts by weight, and the results are shown in Table 1.

[0027]

[Table 1]

Example 3 p-acetoxybenzoic acid 675 g (3.75 mol), hydroquinone diacetate 161 g (0.83 mol), 2,6-naphthalenedicarboxylic acid 174 g (0.81 mol), 6-acetoxy-2-naphthoic acid 25 g (0.11 mol) Mol) as a raw material,
Pellets of wholly aromatic polyester were obtained in the same manner as in Example 1 except that the final polymerization temperature was 350 ° C. The obtained wholly aromatic polyester (referred to as PAR-2) has a temperature of 325 ° C.
Has a melting point of. PAR-2 pellets were used, the compounding temperature and molding temperature were 350 ° C, and the red phosphorus "Hishiguard CP-A15" (manufactured by Nippon Kagaku Kogyo Co., Ltd., surface treated red phosphorus,
Various performance evaluations were performed in the same manner as in Example 1 except that the red phosphorus content was 90% by weight or more). The results are shown in Table 2.

Comparative Example 3 Various performance evaluations were performed in the same manner as in Example 3 except that "Hishigad CP-A15" was not added. The results are shown in Table 2.

Example 4 p-acetoxybenzoic acid 432 g (2.4 mol), m-acetoxybenzoic acid 72 g (0.4 mol), hydroquinone diacetate 233 g (1.2 mol), 4,4'-diphenyldicarboxylic acid 261 g (1.08 mol) Using 19.9 g (0.12 mol) of terephthalic acid as a raw material, pellets of wholly aromatic polyester were obtained in the same manner as in Example 1. The wholly aromatic polyester obtained (designated PAR-3) had a melting point of 303 ° C. Various performance evaluations were performed in the same manner as in Example 1 except that PAR-3 pellets were used and the amount of "Novared" was 1 part by weight. The results are shown in Table 2.

Example 5 p-acetoxybenzoic acid 361 g (2.0 mol), 4,4'-diacetoxydiphenyl 233 g (0.86 mol), 2,6-naphthalenedicarboxylic acid 99 g (0.43 mol), terephthalic acid 71
Using g (0.43 mol) as a raw material, pellets of wholly aromatic polyester were obtained in the same manner as in Example 1. The obtained wholly aromatic polyester (referred to as PAR-4) has a temperature of 304 ° C.
Has a melting point of. Various performance evaluations were performed in the same manner as in Example 1 except that PAR-4 pellets were used and the amount of "Novared" was 1.5 parts by weight. The results are shown in Table 2.

[0032]

[Table 2]

From the results of the above Examples and Comparative Examples, it can be seen that according to the present invention, a composition in which the flame retardancy is remarkably improved while maintaining the excellent characteristics as an aromatic polyester is obtained. In Comparative Example 2 in which the halogen-based flame retardant was used, the performance deterioration due to thermal deterioration during molding was remarkable.

[0034]

Industrial Applicability According to the present invention, there is provided a resin composition in which flame retardancy is remarkably improved without impairing the excellent properties of wholly aromatic polyester.

Claims (1)

[Claims] 1. A wholly aromatic polyester resin composition, wherein 0.05 to 5 parts by weight of red phosphorus is blended with 100 parts by weight of the wholly aromatic polyester.