JPH0245644B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel polyester copolymers. Glycol components forming conventionally widely commercially available polyester resins are often glycols in which both hydroxyl groups are primary, such as ethylene glycol in polyethylene terephthalate resin and tetramethylene glycol in polybutylene terephthalate resin. This is because the primary hydroxyl group has high reactivity and easily forms an ester bond. The two hydroxyl groups of 2-methyl-1,3-propanediol used in the present invention are both primary hydroxyl groups, and have almost the same reactivity as tetramethylene glycol, and are similar to ethylene glycol, tetramethylene glycol, etc. , when reacted with terephthalic acid, poly2
- A polyester copolymer containing a methyl-1,3-propylene terephthalate component can be obtained. Moreover, 2-methyl-1,3-propanediol is a glycol with one methyl group in its side chain and has an asymmetric chemical structure, and the polyester copolymer containing this as one component has an irregular structure. Therefore, the degree of crystallinity is reduced, and effects such as improvement of mold shrinkage rate and discovery of flexibility can be expected. That is, in the present invention, terephthalic acid is used as an acid component, and 1 to 99 mol% of 2-methyl-1,3-propanediol and 99 to 1% of 2-methyl-1,3-propanediol are added as glycol components.
The present invention relates to a method for producing a polyester copolymer, which comprises subjecting a mixed diol consisting of mol% of tetramethylene glycol to a polycondensation reaction. The composition ratio in the glycol component is preferably 5 to 95 mol% of 2-methyl-1,3-propanediol;
Tetramethylene glycol is 95-5 mol%. 2-methyl-1,3-propanediol is 1
If the content of 2-methyl-1,3-propanediol approaches 100 mol%, effects such as improving the mold shrinkage rate and developing flexibility of the resulting copolymer cannot be expected; The melting point of the copolymer gradually decreases, and although it becomes amorphous and its transparency increases, its thermal and mechanical strength decreases, and its uses are limited. The polyester copolymer of the present invention has irregularly distributed repeating units represented by the following formulas A and B, where A is 1 to 99 mol% and B is 99 to 1 mol%.
It is a polyester copolymer composed of mol%. Conventional methods for producing polyester can be applied as they are to producing the above-mentioned polyester copolymer. That is, it can be produced by either a method of directly polycondensing a dicarboxylic acid compound and a diol compound, or a method of reacting a lower alkyl ester of a dicarboxylic acid or a halogen derivative with a diol compound. An example of a polycondensation method by the so-called transesterification method using a lower alkyl ester of dicarboxylic acid is dimethyl terephthalate and an excess number of moles, that is, a total of 1.1 to 2.0 times the amount of tetramethylene glycol and 2-methyl-1,3- A transesterification reaction is carried out on a mixed diol of propanediol using an ordinary esterification catalyst under a nitrogen atmosphere at a temperature of approximately 150 to 240°C under normal pressure, methanol is distilled out, and catalysts and color inhibitors are added as necessary. After adding etc., at about 200 to 280℃ under reduced pressure of 5 mmHg or less
Polycondensate with A wide range of catalysts can be used as the catalyst, including titanium compounds such as tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraiso-propoxytitanium, and tetrabutoxytitanium, di-n-butyl-tin-dilaurate, and di-n-butyl-tin-dilaurate. -n-Butyl-tin-oxide, tin compounds such as dibutyl-tin-diacetate, combinations of acetates such as magnesium, calcium, zinc, and ammonium oxide or the above-mentioned titanium compounds. These catalysts are preferably used in an amount of 0.002 to 0.8% by weight based on the total copolymer produced. In addition, phosphorus-containing compounds such as phosphorous acid, triphenyl phosphate, tridecyl phosphate, and triphenyl phosphate are effective as coloring inhibitors, and should be used in an amount of 0.001 to 0.3% by weight based on the total copolymer produced. It is preferable to use In addition to the coloring inhibitor, additives such as polymerization accelerators, brighteners, and light-fastening agents can be added depending on the purpose, and are effective. The polyester copolymer obtained by the present invention is produced using terephthalic acid, 2-methyl-1,3-propanediol, and tetramethylene glycol as starting materials, and other copolymer components such as adipic acid and azelaic acid. , polyvalent aliphatic carboxylic acids such as sebacic acid, isophthalic acid,
Polyvalent aromatic carboxylic acids such as trimellitic acid, pyromellitic acid, 2,6-naphthalene dicarboxylic acid, ethylene glycol, propylene glycol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanediol, cyclohexanedimethanol, trimethylol Polyhydric alcohols such as propane and pentaerythrite are used. The copolymer obtained by the present invention can be used as a molding material or an adhesive material. EXAMPLES The present invention will be explained in detail below with reference to Examples, but the present invention is not limited thereto. In addition, parts in the examples mean parts by weight, and the measured values in Table 1 were obtained by the following measurements. (1) Content of poly2-methyl-1,3-propylene terephthalate component This was determined by analyzing the NMR (nuclear magnetic resonance) spectrum of the obtained resin. (2) Intrinsic viscosity Measured in orthochlorophenol at 25°C. (3) Melting point (softening point) and relative crystallinity The thermal behavior of each resin was measured using a Perkin Elmer DSC-1B differential scanning calorimeter, and the peak area based on melting was calculated using polybutylene terephthalate resin (Table 1). Comparative example 1) peak area is 100%
It is expressed as a relative ratio when In addition, the softening point of the amorphous resin was measured using a micro melting point measuring device manufactured by Yanagimoto Shoji Co., Ltd. Example 1 194.0 parts of dimethyl terephthalate, 121.5 parts of tetramethylene glycol, 2-methyl-1,3-
13.5 parts of propanediol and 0.20 parts of titanium tetrabutoxide catalyst were charged into a reaction vessel equipped with a double helical ribbon stirring blade, and the mixture was placed under a nitrogen stream at normal pressure.
Heat at 180℃ for 1 hour, then at 230℃ for 2.5 hours,
94% of the theoretical amount of methanol was distilled out. After adding 0.02 parts of trimethyl phosphate to the reaction mixture, the temperature was raised to 250°C, and the pressure in the system was reduced to 0.2 parts over 40 minutes.
The pressure was reduced to mmHg, and the reaction was carried out under these conditions for 3.5 hours. Example 2 and Comparative Example 1 Polymerization was carried out under exactly the same polymerization conditions as in Example 1, with the amounts shown in Table 1. Table 1 shows the physical properties of each polymer obtained. 【table】

Claims (1)

[Claims] 1 Terephthalic acid is used as the acid component, and 1 to 99 mol% of 2-methyl-1,3 is added as the glycol component.
- A method for producing a polyester copolymer, which comprises subjecting a mixed diol consisting of propane diol and 99 to 1 mol % of tetramethylene glycol to a polycondensation reaction.