JPH0543749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to crystalline polyethylene terephthalate resin compositions with fast crystallization rates useful in injection molding applications. Polyethylene terephthalate takes advantage of its excellent properties to be used in fibers, films,
Although it is widely used in fields such as bottles, in the field of injection molding, it has the potential to become an extremely excellent molding material.
It's not used that much. This is because polyethylene terephthalate has a slow crystallization rate at low temperatures.
It is necessary to maintain the mold temperature at 160° C. or higher during injection molding, and such a high mold temperature significantly lengthens the molding cycle, which is unfavorable in terms of production. To shorten the molding cycle, reduce mold temperature.
If the temperature is set near 100°C, crystallization will hardly proceed, and the mechanical properties, dimensional stability, and surface appearance of the molded product will be extremely poor. Various methods have been proposed in the past to improve these drawbacks. For example, Japanese Patent Publication No. 44-7542 discloses that inorganic particles, typically talc, and organic acid salts, such as sodium stearate, increase the crystallization rate of polyethylene terephthalate. Although the mold temperature can be lowered by such a method, a high temperature of 150 to 130° C. is still required, which is not very practical. Furthermore, in Japanese Patent Publication No. 47-3027, inorganic particles such as talc are given the general formula R ₁ -O [-R ₂ -O] _o - R ₁ (where R ₁ is C ₁ to C ₁₀ Aromatic, aliphatic, hydrocarbon groups consisting of a combination thereof, or hydrocarbon organic groups containing nitrogen, sulfur, phosphorus, or oxygen as a part thereof,
R ₂ is a C ₂ to C ₂₂ aliphatic hydrocarbon or a chain [−
an aliphatic hydrocarbon organic group containing nitrogen, oxygen, phosphorus, or sulfur in part or all of R ₂ of R ₂ −O] _o --;
n is an integer from 1 to 200. ) molecular weight
A method of promoting crystallization of polyethylene terephthalate by blending more than 100 compounds is shown. This method is certainly a good method for lowering the mold temperature, but in order to lower it to 100℃ or less, a large amount of the compound represented by the general formula R ₁ -O [-R ₂ -O] - R ₁ is blended. This may cause the compound to bleed out or deteriorate the general mechanical properties of the composition. Furthermore, if the molecular weight of the compound is increased in order to eliminate bleed-out, the compatibility with polyethylene terephthalate deteriorates, resulting in a disadvantage that the general mechanical properties of the composition deteriorate. The inventors of the present invention have conducted intensive research to solve the above-mentioned drawbacks of the prior art, and as a result, have arrived at the composition of the present invention that solves these problems. That is, the present invention comprises (A) component: 100 parts by weight of polyethylene terephthalate, and (B) component: General formula 1 to 20 parts by weight of an organic polymer represented by [wherein R ¹ is an alkylene group having 2 to 5 carbon atoms,
R ² is an aliphatic, alicyclic, aromatic, or a combination thereof hydrocarbon group having 1 or more carbon atoms, or a hydrocarbon terminal group containing nitrogen, sulfur, phosphorus, oxygen, or halogen as a part thereof, R ³ is hydrogen or methyl group, n is an integer from 1 to 50, m is from 10 to
200 integers. ] This is a polyethylene terephthalate resin composition obtained by kneading the following. Next, the present invention will be explained in detail. The polyethylene terephthalate used as component (A) of the present invention is a polyester mainly composed of repeating units of ethylene terephthalate. Generally, it is produced using polyethylene glycol and terephthalate acid, and other acid components and glycol components may be copolymerized within a range that does not impair crystallinity. Acid components include dicarboxylic acids such as isophthalic acid, naphthalene dicarboxylic acid, adipic acid, sebacic acid, and cyclohexanedicarboxylic acid, and glycol components include trimethylene glycol, tetramethylene glycol, hexamethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene. Examples include glycol, a copolymer of polyethylene glycol and polypropylene glycol, and the like. Generally, at least 80 mol%, preferably 90 mol% or more of the acid component and glycol component are ethylene glycol and terephthalic acid, respectively, and preferably at least 80 mol% or more, more preferably 90 mol% or more of ethylene. Polyethylene terephthalate containing terephthalate repeat units is used. This (A) component polyethylene terephthalate is
Intrinsic viscosity measured at 30℃ in a 1:1 weight ratio mixed solvent of phenol and tetrachloroethane is 0.3 or more,
Preferably 0.5 or more, melt polycondensation reaction,
Alternatively, it can be produced by a method combining this and solid phase polymerization reaction. Component (B) has the general formula In the organic polymer represented by, R ¹ is an alkylene group having 2 to 5 carbon atoms, and R ² is an aliphatic, alicyclic, aromatic, or a combination thereof hydrocarbon group having 1 or more carbon atoms, or one thereof. Nitrogen, sulfur, phosphorus,
Hydrocarbon terminal group containing oxygen or halogen, R ³ is hydrogen or methyl group, n is 1 to 50, preferably 2
~30, m is an integer from 20 to 200. Such a polymer can be obtained by polymerizing the following monomers. These include polyethylene glycol monomethyl ale (meth)acrylate, polypropylene glycol monomethyl ether (meth)acrylate, polytetramethylene glycol monoethyl ether (meth)acrylate, and monomethyl ether (meth)acrylate, which is a copolymer of ethylene glycol and propylene glycol. There are (poly)alkylene glycol monoalkyl ether (meth)acrylates and phenoxypolyalkylene glycol (meth)acrylate. The organic polymer used here is a 10-200 mer. The organic polymer of component (B) can be polymerized by an appropriately selected method such as non-catalytic thermal polymerization, radical polymerization, cationic polymerization, anionic polymerization, coordination polymerization, etc. depending on the polymerization performance of the monomer. Its blending amount is polyethylene terephthalate 100
The amount is 1 to 20 parts by weight, and if it is less than 1 part by weight, the effect of the present invention is not achieved, and if it exceeds 20 parts by weight, mechanical properties and heat resistance will deteriorate, which is not preferable. The present invention solves the disadvantages of the prior art, that is, when the amount of the compound added is increased to lower the mold temperature, the compound bleeds out, and in order to suppress this, the molecular weight of the compound is increased. Increasing this will reduce the compatibility with polyethylene terephthalate, and as a result, the general mechanical properties of the composition will be improved. The reason for this is not clear, but by increasing the molecular weight while having a low-molecular alkylene glycol chain represented by the general formula [-R ¹ -O]-R ² in the side chain, the compatibility with polyethylene terephthalate is improved by the side chain. It is presumed that because it is polymerized while being maintained, even if it is blended in a large amount, it will not significantly deteriorate the bleed-out or general mechanical properties. The present invention can be expected to be even more effective by using the conventionally used core materials and crystallization promoters together. Examples of these nucleating agents and crystallization promoters include inorganic compounds such as talc, crew, mica, and silica, and alkali metal salts such as stearic acid, montanic acid, and ethylene and methacrylic acid copolymers. A reinforcing agent such as glass fiber, carbon fiber, wollastonite, whiskers, etc. can be added to the polyethylene terephthalate of the present invention. In particular, it is preferable to add glass fiber in an amount of 5 to 60% by weight based on the total composition, as this significantly improves mechanical properties. Furthermore, in the present invention, flame retardants, ultraviolet absorbers, antioxidants, colorants, and hydrolysis-resistant agents may be added.
Furthermore, other thermoplastic resins such as polyethylene, polypropylene, modified polyolefin, polystyrene, polycarbonate, polyamide, polybutylene terephthalate, etc. may be blended. The polyethylene terephthalate resin composition of the present invention is produced by a conventional method. For example, polyethylene terephthalate as the component (A), an organic polymer as the component (B), preferably the above-mentioned nucleating agent, a crystallization promoter, and optionally a reinforcing agent, a flame retardant, a coloring agent, an antioxidant, etc. are mixed appropriately. It is manufactured by dry blending in a machine and then melt-kneading in an extruder, kneader, Burberry mixer, etc. Next, Examples and Comparative Examples of the present invention will be described, but the present invention is not limited in any way by the following examples. Production Example 1 Production of polyethylene glycol monomethyl ether methacrylate polymers (a) and (b) Polyethylene glycol monomethyl ether methacrylate monomer (average molecular weight 400 and
1000) For each 10 parts by weight, 100 parts by weight of ethanol and 2 mol% of azobisisobutyronitrile for each monomer were charged into a glass reactor, and polymerized at 80°C for 3 hours with stirring under a nitrogen stream. . Ethanol was recovered by evaporation from the obtained polymer solution to obtain polymers (a) and (b) of the present invention, respectively. The molecular weight was determined by osmotic pressure method using the obtained polymer as an aqueous solution.
The number average molecular weight of (a) and (b) is 11000 (degree of polymerization 27.5),
It was 19000 (degree of polymerization 19). Examples 1 to 5, Comparative Examples 1 to 10 Polyethylene terephthalate (manufactured by Kuraray, 1:1 mixed solvent of phenol/tetrachloroethane, 30
°C intrinsic viscosity 0.68), polymers (a) and (b) of Production Example 1 and known nucleating agent talc (manufactured by Fuji Talc, LSM100),
Reinforcement glass fiber (manufactured by Asahi Fiberglass,
CS03JA429), for comparison, polyethylene glycol monomethyl ether methacrylate monomers and low polymers (average molecular weights 400, 1000, 4000;
Monomer, 1600; tetramer, 2800; 2.8mer) in Table 1
After dry blending at the ratio shown in 40mmφ,
The mixture was kneaded and granulated using a single screw extruder with L/D=28 (maximum cylinder temperature 280°C). After drying the obtained pellets with hot air at 130°C for 10 hours, the pellets were heated to 280°C and injection pressure using a Nippon Steel injection molding machine N-100B.
400-600Kg/cm ² , cooling time 20 seconds, molding cycle 40
molding at a mold temperature of 90°C. The degree of bleed-out is 180 mm for injection molded sheet (80 x 120 x 2 mm)
°C, after leaving the gear open for one day, observe the sheet surface. If oily or powdery substances are present on the surface, "Yes", and if these do not exist, "No".
I decided that. In addition, the crystallization promotion effect was confirmed for samples prepared by melting each pellet and then rapidly cooling it with ice water.
PerkinElmer differential calorimeter DSC type 60
The crystallization temperatures Tcc and Tc ²⁹⁰ observed when increasing and decreasing the temperature from ℃ to 290℃ at a rate of 10℃/min are as follows:
Judgment was made based on whether the temperature moved to the lower temperature side or higher temperature side. The lower the Tcc, the lower the mold temperature can be set.
The higher the Tc ²⁹⁰ , the faster the molding cycle. The tensile strength was measured in accordance with ASTM D-638. The results are shown in Table 1. From this table, polymers (a) and (b) of component (B) according to the present invention
Although the composition containing polyethylene glycol dimethyl ether has a significantly larger molecular weight than the comparative example containing polyethylene glycol dimethyl ether, it has good compatibility with polyethylene terephthalate, and no decrease in tensile strength is observed. 【table】

Claims (1)

[Claims] 1. Component (A): 100 parts by weight of polyethylene terephthalate; Component (B): General formula 1 to 20 parts by weight of an organic polymer represented by [wherein R ¹ is an alkylene group having 2 to 5 carbon atoms,
^R2 is an aliphatic, alicyclic, aromatic, or a combination thereof hydrocarbon group having 1 or more carbon atoms, or a hydrocarbon terminal group containing nitrogen, sulfur, phosphorus, oxygen, or halogen as a part thereof, R ³ is hydrogen or methyl group, n is an integer from 1 to 50, m is from 10 to
200 integers. ] A polyethylene terephthalate resin composition obtained by kneading.