JPH0459344B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester resin composition, and more particularly to a polyester resin composition whose crystallization rate is improved by incorporating a metal salt of a cyclic organic phosphate. Polyesters such as polyethylene terephthalate and polybutylene phthalate are widely used as molded products such as fibers, films, and bottles because of their excellent physical properties. However, since polyester has a slow crystallization rate, the molding cycle is low and it is necessary to raise the mold temperature. In order to overcome these difficulties and further improve the physical properties, it has been proposed to use a crystal nucleating agent or a crystallization promoter. For example, Japanese Patent Publication No. 44-7542 discloses neutral clays, metal oxides, sulfates, phosphates, etc.
Metal salts of organic carboxylic acids are disclosed in Japanese Patent Publication No. 46-29977, Japanese Patent Publication No. 47-14502, Japanese Patent Publication No. 48-4097, and Japanese Patent Publication No. 48-4098, and Japanese Patent Publication No. 47-27140 The publication discloses alkali metal salts such as phosphonic acid and phosphinic acid,
Japanese Patent Publication No. 48-5258 discloses metal salts of phosphonic acid or phosphonic acid. However, these compounds have disadvantages such as insufficient effects and poor uniform dispersibility in polyester, and are not practically satisfactory. The present inventors have carried out extensive research in order to obtain a compound that can significantly improve the crystallization rate of polyester, has good affinity with polyester, and can be added homogeneously. As a result, the following general formula ()
The present invention has been achieved by discovering that the compound represented by is an excellent crystallization promoter that achieves the above object. That is, the present invention uses a compound represented by the following general formula () for 100 parts by weight of thermoplastic polyester.
The object of the present invention is to provide a polyester resin composition containing 0.001 to 10 parts by weight. (In the formula, R ₁ and R ₂ are a hydrogen atom, an alkyl group,
It represents an arylalkyl group, an aryl group, or an alkylaryl group, and X represents a direct bond, an alkylidene group, or a sulfur atom. M represents a metal atom, and n represents the valence of the metal. ) To explain in detail the metal salt of the cyclic organic phosphate represented by the above general formula, the alkylidene group represented by Examples include groups such as cyclooctylidene. The alkyl groups represented by R ₁ and R ₂ include methyl, ethyl, isopropyl, n-butyl, isobutyl, sec-butyl, tertiary-butyl, n-amyl,
Examples include groups such as tertiary amyl, hexyl, heptyl, n-octyl, 2-ethylhexyl, tertiary octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, cyclohexyl, cyclopentyl, Examples of the arylalkyl group include groups such as benzyl, phenylethyl, and phenylpropyl; examples of the aryl group include groups such as phenyl and naphthyl; and examples of the alkylaryl group include groups such as tolyl, xylyl, and isopropylphenyl. can give. In addition, the metal atoms represented by M include Li, Na,
K, Be, Mg, Ca, Sr, Ba, Zn, Cd, Al, Ge,
Sn, Pb, Ti, Zr, Sb, Cr, Bi, Mo, Mn, Fe,
Examples include Co, Ni, etc., and group a metals such as Li, Na, and K, and group a metals such as Mg, Ca, Sr, and Ba are particularly preferred. Specific examples of the compounds represented by the above general formula used in the present invention are shown in Table 1 below. Examples of the thermoplastic polyester used in the present invention include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyneopentylene terephthalate, polyhexylene terephthalate, polyethylene naphthalate, polyhexylene naphthalate, poly-p-ethylene Examples include homopolymers such as benzoate, and those in which part of the above acid component and/or alcohol component is replaced with another copolymer component. In addition to the above-mentioned terephthalic acid and naphthalenedicarboxylic acid, the copolymerization components include phthalic acid, isophthalic acid, 4,4'-phenoxyethanedicarboxylic acid, dicarboxylic acids such as adipic acid, and in addition to the above-mentioned glycol, 1, 10-decanediol,
Examples include glycols such as 1,4-cyclohexanedimethanol, diethylene glycol, and polyethylene glycol. The composition of the present invention may also contain conventionally known additives such as pigments, mica, talc, glass fibers, fillers such as calcium carbonate, heat stabilizers, light stabilizers, flame retardants, and the like. When carrying out the present invention, a conventionally well-known method can be applied as a method for adding the compound represented by the above general formula () to polyester, and it can be added at any stage before, during, or after polymerization of polyester. can do. The present invention will be explained in more detail with reference to Examples below. Example 1 Polyethylene terephthalate with an intrinsic viscosity of 0.66
Example: 1 part by weight of the pigment listed in Table 2 was mixed with 100 parts by weight. Pellets were prepared by melt-mixing using a single-screw extruder. The pellet was placed in a differential calorimeter and heated at a rate of 16°C/min, and the crystallization temperature was measured at 300°C.
The crystallization temperature was measured when the temperature was lowered at a rate of 16° C./min after melting for 5 minutes. In addition, the ratio H/W of the height H of the endothermic peak when the temperature was lowered to the width W at H/2 was determined. The lower the crystallization temperature when the temperature is raised, the higher the degree of crystallinity can be obtained when molded in a low-temperature mold, and the higher the crystallization temperature when the temperature is lowered and the larger the H/W, the higher the crystallization rate. The results are shown in Table-2.

【table】

[Table] Example 2 Polyethylene terephthalate 70 with intrinsic viscosity 0.64
Mix 30 parts by weight of glass fibers with an average length of 5 mm and a diameter of 10 μ and 0.5 parts by weight of the sample listed in Table 3,
Pellets were made by extrusion. Using this pellet, a differential calorific type was used to produce 64°C/
The crystallization temperature was measured when the temperature was raised and when the temperature was lowered for 20 minutes, and the difference (ΔT) was determined. If ΔT is 45°C or higher, molding is possible at a mold temperature of 100°C. The results are shown in Table-3.

[Table] Example 3 Polybutylene terephthalate with intrinsic viscosity 1.16
0.5 part by weight of the sample listed in Table 4 was added to 100 parts by weight and extruded to prepare pellets. This pellet was placed in an automatic scanning differential calorimeter, and after melting at 250°C for 4 minutes, the temperature was lowered at a rate of 10°C/min to measure the crystallization temperature. Further, using this pellet, a sheet with a thickness of 0.8 mm was produced by hot pressing at 250°C. A dumbbell-shaped tensile test piece was punched out from this sheet, and the tensile impact strength was measured at 25°C. The results are shown in Table-4.

[Table] Example 4 and Comparative Example 4 65 parts by weight of dimethyl terephthalate, 65 parts by weight of ethylene glycol, and 0.05 parts by weight of manganese acetate were taken and a transesterification reaction was carried out at 200°C for 2 hours.
Subsequently, 35 parts by weight of adipic acid was added and an esterification reaction was carried out at 220°C for 4 hours.
1) 4 parts by weight and 0.04 parts by weight of antimony trioxide were added, the temperature was raised to 280°C, and a polycondensation reaction was carried out at 0.5 mmHg for 4 hours. The reduced viscosity of the obtained polyethylene terephthalate adipate was 0.78. 16 using this copolymer using an automatic scanning calorimeter.
When we measured the crystallization temperature during cooling at °C/min,
It was 156℃. Furthermore, when polyethylene terephthalate adipate prepared by the same procedure except that No. 1 compound was not added was used, no crystallization temperature was observed when the temperature was lowered.

Claims (1)

[Scope of Claims] 1. A polyester resin composition prepared by blending 0.001 to 10 parts by weight of a compound represented by the following general formula () with 100 parts by weight of a thermoplastic polyester. (In the formula, R ₁ and R ₂ are a hydrogen atom, an alkyl group,
It represents an arylalkyl group, an aryl group, or an alkylaryl group, and X represents a direct bond, an alkylidene group, or a sulfur atom. M represents a metal atom, and n represents the valence of the metal. )