JPH06116485A - Polyester particle mixture - Google Patents

Abstract

PURPOSE:To obtain a polyester particle mixture which is suppressed in the regeneration of oligomers and can give a non-fogging molding by mixing polyester particles with particles prepared by partially hydrolyzing the above particles in a specified mixing ratio. CONSTITUTION:The mixture is prepared by mixing particles of a polyester comprising an aromatic dicarboxylic acid and an aliphatic glycol and having an intrinsic viscosity of 0.65-0.90dl/g and polyester particles prepared by hydrolyzing the above particles and having an intrinsic viscosity lower than that of the above particles by 0.01-0.25dl/g in a ratio of 95:5-10:90. The obtained molding material is suppressed in the regeneration of oligomers, can give a non-fogging molding having good transparency and properties and is reduced in the formation of mold deposit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester particle mixture, which has good physical properties and transparency of the molded product and has reduced cloudiness of the molded product.

[0002]

2. Description of the Related Art Polyester is widely used for fibers, films, bottles, industrial resins and the like because of its excellent mechanical, physical and chemical properties.

In the application of flat or three-dimensional molded products such as films and bottles, many products require transparency depending on the field of use.

Regarding the transparency, in addition to the internal structure of the material, that is, the material itself has a good light-transmitting property, the surface property of the molded article is such that the surface of the molded article has no irregularities and diffuse reflection of light does not occur on the surface. There are two factors that concern

With respect to the surface property of the molded product which controls the latter factor of transparency, a molded product having a considerably smooth surface is obtained depending on the finishing degree of the surface of the cooling drum during film formation and the surface of the mold during molding. . However, for a long time continuously,
As the molding continues, the oligomers precipitated from the polymer adhere to the cooling drum and the mold, which are transferred to the film and the molded product to form irregularities on the surface of the molded product, and irregular reflection of light causes transparency. Lowering results in similar negative results. As a method for preventing this, for example, Japanese Patent Application Laid-Open No. 56-118
420 and Japanese Unexamined Patent Publication No. 3-47830,
There has been proposed a method of suppressing the regeneration of an oligomer at the time of melt molding by partial hydrolysis of a polymer or deactivation of a catalyst by water treatment.

[0006]

In the above-mentioned method, although there is almost no regeneration of the oligomer, there is a problem that the crystallization rate of the polymer is increased and the molded article is slightly clouded due to the crystallization.

The present invention is intended to provide particles for suppressing the regeneration of an oligomer and for obtaining a polyester molded article without clouding.

[0008]

The present invention is a polyester particle composed of an aromatic dicarboxylic acid and an aliphatic glycol, wherein the following two kinds of particles have a weight ratio of A: B = 95:
The particle mixture is 5 to 10:90. However, particle A
Is a polyester composed of an aromatic dicarboxylic acid and an aliphatic glycol having an intrinsic viscosity of 0.65 to 0.90.
The polyester particles are dl / g, and the particles B hydrolyze the particles A and have an intrinsic viscosity of 0.
The polyester particles are in a state of being low by 01 to 0.25 dl / g. The present invention will be described.

In the present invention, the "polyester" means a polyester having an aromatic dicarboxylic acid as a main acid component and an aliphatic glycol as a main glycol component.
Here, "mainly" means that dicarboxylic acid and glycol are 8
It means that it accounts for 5 mol% or more. A technique containing 15 mol% or less of the third component is a technique to which the present invention can be applied.

Examples of the "aromatic dicarboxylic acid" constituting the polyester include terephthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl ketone dicarboxylic acid and diphenoxyethane dicarboxylic acid.

Examples of the "aliphatic glycol" constituting the polyester include ethylene glycol, trimethylene glycol, tetramethylene glycol and hexamethylene glycol.

The third component which can be copolymerized is an aromatic dicarboxylic acid constituting the polyester, a dicarboxylic acid other than an aliphatic glycol, a diol or an oxycarboxylic acid. Specifically, in addition to the above compounds, aromatic dicarboxylic acids such as isophthalic acid, diphenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid, sodium-sulfoisophthalic acid, dibromoterephthalic acid and the like;
Examples thereof include alicyclic dicarboxylic acids such as decalin dicarboxylic acid, tetralin dicarboxylic acid, hexahydroterephthalic acid and the like; aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid and sebacic acid. or,
Examples of the glycol component include aliphatic diols such as pentamethylene glycol, diethylene glycol and triethylene glycol; aromatic diols such as catechol, naphthalene diol, resorcinol and 4,4 ′.
-Dihydroxy-diphenyl-sulfone, bisphenol A ([2,2'-bis (4-hydroxyphenyl) propane]), tetrabromobisphenol A, bishydroxyethoxybisphenol A, etc .; aliphatic diols such as cyclohexanediol; aliphatic Oxycarboxylic acids such as bricolic acid, hydroacrylic acid, 3-oxypropionic acid and the like; alicyclic oxycarboxylic acids such as asiatic acid, quinobaic acid and the like; aromatic oxycarboxylic acids such as salicylic acid, m-oxybenzoic acid, p -Oxybenzoic acid, mandelic acid, atrolactic acid and the like can be mentioned.

Further, within the range where the polyester is substantially linear, a polyfunctional compound having a valence of 3 or more, such as glycerin, trimethylolpropane, pentaerythritol,
Trimellitic acid, trimesic acid, pyromellitic acid, tricarballylic acid, gallic acid, etc. may be copolymerized, and if necessary, a monofunctional compound such as o-benzoylbenzoic acid,
Naphthoic acid or the like may be added.

In the present invention, the "particles" are in the form of ordinary pellets or flakes. Pellet means a regular shape such as a square shape or a cylinder shape having an average particle diameter of 1 to 4 mm, or a crushed irregular shape.

In the present invention, the particles A are so-called "virgin pellets" and have an intrinsic viscosity of 0.65 to 0.90d.
The target is 1 / g. Particles B are obtained by hydrolyzing polyester A. Particles B due to hydrolysis
Indicates that the intrinsic viscosity is lower than that of the particle A by 0.01 to 0.25. When the lower limit of the lower limit of the intrinsic viscosity is less than 0.01, the effect of suppressing the regeneration of the oligomer alone is obtained, but when it is used in the mixture with the particle A, the effect is almost eliminated.
If the amount of decrease in intrinsic viscosity exceeds 0.25, the physical properties of the molded product deteriorate. The preferable range of the amount of decrease in the intrinsic viscosity of the B particles is 0.02 to 0.20.

In the mixture and the mixture of the particles A and the particles B, the weight ratio is 95: 5 to 10:90. When the proportion of the particles B is less than 5%, the physical properties of the bottle are good, but the effect of suppressing the oligomer regeneration is small and the mold stain is not improved. On the other hand, if it is more than 90%, clouding occurs due to the crystallization of the particles B, and the transparency of the product decreases. Therefore, the preferable mixing ratio of the particles of the mixture is 90:10 to 2 for A: B.
It is 0:80.

[0017]

EXAMPLES The present invention will be specifically described below with reference to examples. Each property used in the examples was measured by the following methods.

(A) Intrinsic viscosity: [η] phenol / tetrachloroethane (weight ratio 60/40)
It is calculated from the solution viscosity measured at 35 ° C using the mixed solvent of.

The intrinsic viscosity of the molded product was used as a measure of the physical properties of the molded product.

(B) Transparency of molded product: 160 polymer
After drying at ℃ for 5 hours, cylinder temperature 29 using injection molding machine Dynamelter M-1000M manufactured by Meiki Seisakusho
A preform weighing 50 g is molded at 5 ° C. and blow-stretched to obtain a bottle having an internal volume of 1.5 liters and a body thickness of 0.3 mm. The straight body is cut off, and the haze of the bottle body is measured with a haze meter to determine the transparency of the molded product.

(C) Oligomer (abbreviated as Cy-3) A polymer or a preform of a molded bottle was sampled, dissolved in a hexafluoroisopropanol / chloroform (50/50) mixed solvent, further diluted with chloroform, and then diluted with Millipore. The content of the cyclic trimer is quantified by using ALC / GPX744 manufactured by Waters Co., Ltd. for the filtrate filtered through a filter.

Regarding the haze caused by the unevenness of the bottle surface caused by the transfer of the deposit on the mold to the bottle, it cannot be evaluated without continuous molding for a long period of time. Therefore, this was substituted by the increased amount of oligomers before and after molding.

[0023]

[Reference example]

(Preparation of particles B) Teijin polyester resin TR-855
OT (particle A) was hydrothermally hydrolyzed in an autoclave under the conditions shown in Table 1 to prepare particles B ₁ , B ₂ and B ₃ . The polymer properties are shown in the right column of the table.

[0024]

[Table 1]

[0025]

[Examples 1 to 3 and Comparative Examples 1 to 5] Polyester resin TR-8550T (particles A) manufactured by Teijin Ltd. was used, and the particles B described above were mixed at a predetermined ratio to form bottles. The characteristics of the molded product are shown in Table 2.

When the amount of the particles B is too small (Comparative Example 2), the mold stains are the same as those in the normal case (Comparative Example 1). On the contrary, if the amount is too large, the transparency of the molded product deteriorates (Comparative Example 3). Particle B
If the hydrolysis of is promoted too much, in addition to the transparency of the molded product,
Physical properties also deteriorate (Comparative Example 4). On the contrary, the mold stain is not improved by blending the ones having a low degree of hydrolysis (Comparative Example 5).

[0027]

[Table 2]

Claims (1)

[Claims] 1. A polyester particle mixture comprising an aromatic dicarboxylic acid and an aliphatic glycol, wherein the following two kinds of particles have a weight ratio of A: B = 95: 5 to 10:90. [However, particle A: a polyester particle comprising an aromatic dicarboxylic acid and an aliphatic glycol and having an intrinsic viscosity of 0.65 to 0.90 dl / g. Particle B: Polyester particle in which the particle A is hydrolyzed and its intrinsic viscosity is lower than that of the particle A by 0.01 to 0.25 dl / g. ]