JPH02199120A - Polyester composition - Google Patents

Abstract

PURPOSE:To obtain the title composition having excellent UV absorptivity and being useful for obtaining containers for foods, detergents, etc., by copolymerizing a specified UV absorber in the course of the production of a polyester comprising terephthalic acid and an alkylene glycol component. CONSTITUTION:The title composition having a max. absorption wavelength in the range of 320-380nm is obtained by adding 1-10 pts.wt. per 1000 pts.wt. polyester, UV absorber of the formula [wherein R1 is H, a (substituted) alkyl, a (substituted) aryl, a (substituted) cycloalkyl or an alkenyl; R2 is H or a (substituted) alkyl; and n is 1-5] to the reaction system in any arbitrary stage before completing the reaction in the production of a polyester comprising terephthalic acid alone or together with a lower alkyl ester thereof and at least one alkylene glycol component (e.g. ethylene glycol) and copolymerizing it with the polyester.

Description

Detailed Description of the Invention [Industrial Application Field] Standard products such as soft drinks, sake, wine, foods, cosmetics, detergents, and shampoos include plastic containers and films that transmit light in the wavelength range of 250 nm to 400 nm. The present invention uses a copolymerized ultraviolet absorber that allows the packaging container itself to absorb ultraviolet rays without causing the product to become brittle due to these harmful wavelengths. This invention relates to polyester compositions.

[Prior Art and Problems to be Solved by the Invention] Polyester, particularly polyethylene terephthalate, is widely used in the fields of fibers, films, plastic molding, etc. due to its excellent physical and chemical properties. The field of bottle molding using polyethylene terephthalate has shown remarkable development and demand growth over the past few years. Among these, currently commercially available ultraviolet filter PET (polyethylene terephthalate) bottles generally use a non-reactive triazole ultraviolet absorber used for sake as a master chip. This maximum absorption wavelength has sufficient performance to prevent sake from deteriorating. However, since the ultraviolet absorber is a non-reactive type, there is a problem that sublimation adheres to the mold during the molding stage, especially during injection molding, causing a great deal of trouble in the work. As a result of intensive studies to solve this problem, it was possible to obtain a polyester composition copolymerized with an ultraviolet absorber as disclosed in, for example, JP-A-62-501856 and JP-A-62-501857. It was discovered that mold staining can be significantly prevented by producing this birch polyester composition, leading to the present invention.

The purpose of the present invention is to have excellent ultraviolet absorbing ability and to copolymerize an ultraviolet absorber with polyester, so that when forming packaging materials such as bottles or films, no sublimation of the ultraviolet absorber is generated. It is an object of the present invention to provide a polyester composition that can improve workability by extremely reducing mold stains.

[Means for solving problems]

The present invention has the following configuration to solve the above object. That is, 1) In producing a polyester consisting of terephthalic acid or its lower alkyl ester and at least one alkylene glycol component, at any stage until the production reaction is completed, the following structural formula [however, n-1 to 5] preferably 2 to 10 parts by weight per 1000 parts by weight of polyester.
A polyester composition copolymerized with the polyester in an amount of 5 parts by weight and having a maximum absorption wavelength in the range of 320 nm to 380 nm.

(However, in the above structural formula, R1 is hydrogen or an alkyl group.

A substituted alkyl group, an aryl group, an IF-substituted aryl group, a cycloalkyl group, a substituted cycloalkyl group, or an alkenyl group, and R3 is hydrogen, an alkyl group, or a substituted alkyl group. ) 2) A polyester composition in which R+ and Rt are hydrogen.

3) It has an intrinsic viscosity of 0,650 to 1.20, and the acid component is a terephthalic acid residue of 85 to 85! 00 mole%.

Glycol component is ethylene glycol residue 85-100
A polyester composition in which a heat stabilizer, a coloring agent, an antioxidant, etc. can be used as an additive in addition to a copolymerized ultraviolet absorber as an additive.

4) A molded article made of the polyester composition according to any one of 1) to 3).

The copolymerization component of the polyester composition in the present invention is based on 1000 parts by weight of the produced polymer! The concentration is between 10 and 10 parts by weight, preferably between 2 and 5 parts by weight. If the amount added is less than 1 part by weight, the ultraviolet absorbing ability of the resulting polymer will be weak and sufficient effects cannot be obtained, and if the amount is more than 10 parts by weight, the intrinsic viscosity during polymerization will be 0.50%. The above cannot be obtained and unreacted ultraviolet absorber remains.

The polyester composition according to the invention has an intrinsic viscosity of 0.50
~1.20 and the acid component is terephthalic acid residue 85~10
0 mol% and the glycol component consists of ethylene glycol fi & 85 to 100 mol%, other acid components include isophthalic acid, adipic acid, trimellitic acid, etc. and derivatives thereof, and other glycol components include:
Examples include propylene glycol, 1,4-butanediol, neopentyl glycol, and pentaerythritol. In addition to the ultraviolet absorber in the copolymerization component, a heat stabilizer, a coloring agent, and an antioxidant may be added as additives.According to the present invention, a benzophenone ultraviolet absorber is reacted with the polymer. Seshime 320nm to 380nm
It has the ability to absorb ultraviolet rays with a maximum absorption wavelength within the range of .

The structure of the benzophenone compound having ultraviolet absorbing properties in the present invention undergoes a condensation reaction on a polymer chain and has a glycol functional group as a terminator. These compounds preferably have a molecular weight of 200 to 600.

The benzophenone compound according to the present invention cannot be extracted from the following structural formula, and is added at a concentration of 1 to 10 parts by weight per 1000 parts by weight of the produced polymer. however,
In the above formula, R6 is hydrogen, a furkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a cycloalkyl group, a substituted cycloalkyl group, an alkenyl group, etc., and Rt is hydrogen, an alkyl group, or a substituted alkyl group.

When producing a copolymerized polyester using the above ultraviolet absorber 111 or more, the ultraviolet absorber can be added at any time before the end of the polycondensation reaction, but before the esterification reaction or before the transesterification reaction. There are no particular restrictions on the method of addition, but it is preferable from the viewpoint of workability to disperse the mixture in an ethylene glycol solution. An ultraviolet absorber may be added beforehand, but in this case there is a risk that the copolymerization may not be carried out sufficiently.When obtaining the polyester composition of the present invention, any known polycondensation catalyst may be used as a catalyst for the polycondensation reaction. For example, G a 7 S b ) T i
/ S n etc. can be mentioned.

As an example of specific reaction conditions, the esterification or transesterification reaction is carried out at 180°C to 260°C for 2 to 4 hours,
The polycondensation reaction is carried out at 250°C to 300°C under reduced pressure of 1 Torr or less.
C. for 2 to 6 hours. Also, if necessary,
Below the melting point in an inert gas atmosphere or vacuum 10-50℃
It is also possible to carry out solid phase polymerization under heating.

In this way, according to the present invention, it is possible to obtain a molded article of a copolymer composition that suppresses sublimation of the ultraviolet absorber during molding and suppresses deterioration of the filler due to ultraviolet rays.

The present invention will be explained in more detail below with reference to Examples.

(Example) Bishydroxyethyl terephthalate (254g, 1
．． 0 mol), terephthalic acid (83 g, 0.5 mol), and UV absorber 258, mp 93.5-94.1) in 1.01 g (0
, 35%/polymer) and esterification at 255°C.
After completing the esterification, 3.6 ml (100 ppm/polymer) of 0.8% aqueous solution of Ge01 was added, and 0.76 ml of 5% ethylene glycol solution of trimethyl phosphoric acid was added.
mj (30 ppm in terms of p/polymer) was added, and the degree of vacuum was increased from 760 mm 1 g to 1 mmHg or less in about 1 hour, and the polymerization temperature was raised from 255°C to 285°C. Thereafter, a reaction was carried out for about 3 hours at 285° C. under high vacuum of 1 mmHg or less. The intrinsic viscosity (η) of the obtained polymer was 0.
It was 70. The thus obtained polymer was subjected to solid phase polymerization at 225° C. under high vacuum of 1 mmHg or more for about 8 hours. The viscosity of the chip thus obtained was 0.80.

[Evaluation method]

l) Evaluation of ultraviolet absorption ability: 20 mg of the chips are accurately weighed, dissolved in 0.2 ml of a mixed solvent of phenol/tetrachloroethane (60/40 weight ratio) while heating, and further diluted with a chloroform solution. 355 of this adjustment liquid
The transmittance in nm is measured and used as a measure of ultraviolet absorption ability.

2) Evaluation of the sublimation property of the ultraviolet absorber: Perform solid phase polymerization in the same manner as in the example, and compare the difference in ultraviolet absorption ability using evaluation method 1) for the chips before and after the same phase polymerization, and evaluate the degree of sublimation of the ultraviolet absorber. Estimate. Furthermore, actual bottle molding will be carried out and the degree of contamination of the mold will be observed. The molding conditions were a cylinder temperature of 275°C and a mold temperature of 15°C, and the presence or absence of mold staining was observed after 800 continuous moldings were completed.

These two measurement methods are used as a measure of the sublimability of the ultraviolet absorbent.

[Comparative Examples 1 to 5] Addition of low and high concentrations of ultraviolet absorbers shown in Examples,
Constituent formula (JP-A-62-501857) copolymer products, ultraviolet absorber Tinuvin 326 additives used in commercial products, and evaluation of ultraviolet absorber-free world [Effects of the invention] From the above, in the present invention, The polyester composition, which is mainly composed of terephthalic acid and ethylene glycol and copolymerized with a benzophenone UV absorber, has excellent UV absorbing ability and can be used without mold staining due to sublimation of the UV absorber during molding. It was found to be advantageous for sex.

Therefore, it is clear that the polyester composition of the present invention can promote polyester moldings suitable for packaging containers for soft drinks, sake, wine, etc.

Claims (1)

[Claims] 1) In producing a polyester consisting of terephthalic acid or its lower alkyl ester and at least one alkylene glycol component, the following structural formula ▲ Numerical formula, There are chemical formulas, tables, etc. ▼ Polyester in which 1 to 10 parts by weight of an ultraviolet absorber shown by [where n = 1 to 5] is copolymerized with the polyester and has a maximum absorption wavelength in the range of 320 nm to 380 nm. Composition. (However, in the above structural formula, R_1 is hydrogen, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a cycloalkyl group, a substituted cycloalkyl group, an alkenyl group,
_2 is hydrogen, an alkyl group, or a substituted alkyl group. 2) The polyester composition according to claim 1, wherein R_1 and R_2 are hydrogen. 3) It has an intrinsic viscosity of 0.50 to 1.20, the acid component is 85 to 100 mol% of terephthalic acid residues, the glycol component is 85 to 100 mol% of ethylene glycol residues, and a copolymer component is used as an additive. The polyester composition according to claim 1, in which in addition to the ultraviolet absorber, a heat stabilizer, a coloring agent, an antioxidant, etc. can be used as necessary. 4) A molded article made of the polyester composition according to any one of claims 1 to 3.