JPH059275A - High-speed crystalline copolymerized polyethylene terephthalate resin for molding material and method for producing the same - Google Patents

Abstract

(57) [Summary] [Objective] The object is to provide a copolymerized polyethylene terephthalate resin which has a high crystallization rate and does not cause any trouble during the molding operation without special crystallization treatment. . [Structure] 70 to 90% by weight of ethylene terephthalate component, an intrinsic viscosity [η] of 0.5 or more, and a glass state measured with a differential scanning calorimeter at a temperature rising rate of 10 ° C./min. Crystallization exothermic peak is clearly expressed and its calorific value is 1
High-speed crystalline copolymerized polyethylene terephthalate resin for molding materials, which is 0 mJ / mg or more. This resin is produced by casting or reprecipitating a solvent solution of copolymerized polyethylene terephthalate in a non-solvent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymerized polyethylene terephthalate resin for a molding material, which is suitable for molding a transparent thick container, a shrinkable film and the like, and can be smoothly dried during molding. .

[0002]

2. Description of the Related Art A crystalline polyester resin containing ethylene terephthalate as a main constituent is a gas barrier,
It is used in soy sauce bottles, bottles for carbonated drinks, alcohol beverage containers, etc., by utilizing its solvent resistance. Recently, due to its high melting point, it has been used for high temperature molded products such as openable trays, exteriors of heat appliances as engineering plastics, and electric parts. Furthermore, the field of application is expanding as a container for cosmetics and a container for detergents by taking advantage of the aroma-retaining property and luster.

By the way, the polyethylene terephthalate resin, which is a raw material of the shrink film used for the label of the packaging container, has a glass transition point or a melting point lowered as necessary. Most of the means adopted are copolymerization to the extent that the characteristics of polyester are not impaired. On the other hand, when polyethylene terephthalate-based resin is used as a molding material by an extrusion molding method to mold a film or the like, the hopper-type should be adjusted so that the pellets are stably moved from the hopper to the cylinder of the extruder. It is generally practiced to reduce the water content of the resin to 100 ppm or less and further crystallize it while sending dry air at about 150 ° C. with a dryer.

Copolymerized polyethylene terephthalate
-The resin has a significantly lower crystallization rate than the homopolymer, and even if the above heating means is adopted during extrusion molding,
-Dryer-It solidifies into a "wrinkle" before crystallizing in it. Therefore, a problem occurs in which pellets do not move in the extruder. In order to eliminate such troubles, a resin maker uses a Banbury mixer or solid-state polymerization equipment to gradually heat the resin pellets while stirring to crystallize the pellets so that they do not stick together, and then dry them. ,
At present, the crystallized and dried pellets are shipped in a moisture-proof package and shipped to a resin molding company, which raises the cost and hinders the market expansion.

On the other hand, many nucleating agents are known for increasing the crystallization rate of polyethylene terephthalate (European Patent No. 0025573, US Pat. No. 37).
61450, U.S. Pat. No. 3,624,041, U.S. Pat. No. 3,595,818, U.S. Pat. No. 3,516,957, British Patent No. 1,505,599, U.S. Pat. No. 3,962,368.
U.S. Pat. No. 3,575,931 and U.S. Pat. No. 3553.
No. 157, JP-A-46-29917, etc.) leads to drawbacks such as a decrease in the molecular weight of polyethylene terephthalate, unusability in food packaging applications, and poor low temperature impact resistance. Often.

[0006]

The present invention provides a nucleating agent,
An object of the present invention is to provide a copolymerized polyethylene terephthalate resin which has a high crystallization rate without the addition of a plasticizer and does not cause any trouble during the molding operation without special crystallization treatment. .

[0007]

Means for Solving the Problems That is, the present invention is a copolymerized polyethylene terephthalate having an ethylene terephthalate component of 70 to 90% and an intrinsic viscosity [η] of 0.5 or more, A molding material characterized in that a crystallization exothermic peak from a glass state, which is measured by a differential scanning calorimeter at a temperature rising rate of 10 ° C./min, clearly appears, and the calorific value is 10 mJ / mg or more. High-speed crystalline copolymerized polyethylene terephthalate resin for use.

Copolyethylene terephthalate of the present invention
Since the resin has a high crystallization rate, the above trouble does not occur at the time of molding without adding a crystal nucleating agent or a plasticizer. The copolymerized polyethylene terephthalate resin of the present invention is prepared by dissolving a polymer composed of copolymerized polyethylene terephthalate in a solvent to form a solvent solution,
It can be produced by casting this solution or by adding a non-solvent to this solution to cause precipitation. At this time, the polymer does not cause a decrease in molecular weight or a glass transition point, and a high crystallization rate can be achieved.

The copolymerizable component used in the present invention includes isophthalic acid, adipic acid, sebacic acid, naphthalene-1,4- or -2,6-dicarboxylic acid, diphenylether-4,4'-dicarboxylic acid. Acid components such as propylene glycol, butylene glycol, neopentyl glycol, cyclohexane dimethanol, 2,2-bis (4-hydroxyphenyl) propane, and other glycol components; P-oxybenzoic acid Examples thereof include acids and oxy acids such as P-hydroxybenzoic acid.

The content of the ethylene terephthalate component in the copolymerized polyethylene terephthalate is preferably 70 to 90%, and when it is 90% or more, the glass transition point or the melting point is high, and crystallization is easily performed, and the shrink film It becomes difficult to obtain a high shrinkage ratio, which is a characteristic of On the other hand, if it is less than 70%, the melting point or glass transition point becomes too low, and the crystallinity is suppressed so that the required heat resistance cannot be obtained. Polyethylene terephthalate in the present invention
The resin having an intrinsic viscosity [η] of 0.5 or more is preferable. When the intrinsic viscosity [η] is 0.5 or less, practical physical properties as a polymer cannot be exhibited.

In the present invention, the solvent used for the casting operation and the reprecipitation operation may be any solvent that dissolves polyethylene terephthalate, for example, phenol.
/ Tetrachloroethane (1: 1 by volume) mixture, m-
Cresol, phenol / 2,4,6-trichlorophenol (10: 7 by volume) mixture, 0-chlorophenol, dichloroacetic acid, hexafluoroisopropanol
And a mixed solution of phenol / dichloroethane, trifluoroacetic acid, a mixed solution of hexafluoroisopropanol / chloroform, a mixed solution of hexafluoroisopropanol / tetrachloroethane, and the like.

The casting operation is carried out by casting a polymer solution and removing the solvent by heating. The reprecipitation operation is performed by adding a non-solvent to the polymer solution. The polymer concentration of the solution in that case may be appropriate, but [η] 1.
About 0% is about 3%, and about [η] 0.7 is about 5%.
About 6% is a standard for efficient reprecipitation. Non-solvents include alcohols, ethers, ketones, hydrocarbons, chlorinated hydrocarbons, esters, etc.
Specifically, for example, methanol, acetone, chloroform, diethyl ether or the like is used. Non-solvent is a solution
The volume is preferably about 10 times.

The casting and reprecipitate obtained as described above are crushed and used as a molding material. The polyethylene terephthalate resin of the present invention can be molded by any processing method applied to plastics. For example, injection molding, extrusion molding, vacuum molding, pressure molding, biaxial stretching blow molding and the like can be mentioned. When the copolymerized polyethylene terephthalate of the present invention is put to practical use, an antioxidant can be added, if necessary, in order to prevent oxidative deterioration at high temperatures.

[0014]

The present invention will be described in the following examples. The intrinsic viscosity and the differential scanning calorie (DSC) were measured by the following methods. The intrinsic viscosity [η] was measured by using a polymer in a mixed solvent of phenol / tetrachloroethane (50:50 by weight).
Was dissolved in 1% and measured at 25 ° C. The DSC measurement is
Enclose approximately 10 mg of polymer in a sample container and
After vacuum drying at night, in a DSC cell, in a nitrogen stream, 2
Melt at 90 ° C for 3 minutes, then quench on dry ice,
Remove moisture by vacuum drying at room temperature, then from room temperature to 280 ℃
The temperature was raised and lowered at 10 ° C./min, and a crystallization peak temperature Tc + and Tc ⁻ was measured by inserting a hold at 280 ° C. for 5 minutes. The measurement was performed in nitrogen.

A copolymerized polyethylene terephthalate consisting of 90% ethylene terephthalate and 10% ethylene isophthalate was polymerized by the DMT method. Manganese acetate was used as the transesterification catalyst, germanium dioxide was used as the polymerization catalyst, and trimethyl phosphate was used as the oxidation stabilizer.
Was used. The [η] of the obtained polymer was 0.8. About this copolymer polyethylene terephthalate,
The DSC curves before and after reprecipitation were examined.

FIG. 1 is a DSC curve of the above melt-cooled copolymerized polyethylene terephthalate before reprecipitation. T
c + and Tc ^- corresponding to peak - it can be seen that click is hardly recognized. FIG. 2 shows that the above-mentioned copolymerized polyethylene terephthalate is mixed with phenol / ethane tetrachloride (volume ratio of 50: 5).
0) to a concentration of 6%, reprecipitated with 10 volumes of ethanol, and then extracted with ethanol under reflux,
Then, the DSC curve of the copolymerized polyethylene terephthalate which was vacuum dried overnight at 130 ° C. and melt-quenched was shown. Tc + peak - click and Tc ^- peak - click are clearly observed, Tc + Pi - calorific value of click it can be seen that faster significantly crystallization speed by reprecipitation be 26 mJ / mg . As a result, the coprecipitated polyethylene terephthalate after reprecipitation solidifies into a "wrinkle" before being crystallized in the hopper-dryer during extrusion molding, causing a problem that pellets do not move to the extruder. I didn't.

[0017]

The copolymerized polyethylene terephthale of the present invention
-The resin has a property that the crystallization rate is fast, and even when a crystal nucleating agent or a plasticizer is not added, it does not impair the shrinkage property when forming a shrinkable film for packaging, and the hopper-dryer -It is possible to prevent the trouble of moving from the extruder to the extruder.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] August 15, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Added

[Correction content]

[Brief description of drawings]

FIG. 1 shows a DSC curve of copolymerized polyethylene terephthalate before reprecipitation in the method of the present invention.

FIG. 2 shows a DSC curve of copolymerized polyethylene terephthalate after reprecipitation in the method of the present invention.

Claims (2)

[Claims] 1. An ethylene terephthalate component is 70 to 90.
% Of copolymerized polyethylene terephthalate,
Intrinsic viscosity [η] is 0.5 or more, and the crystallization exothermic peak from the glass state, which is measured by a differential scanning calorimeter at a temperature rising rate of 10 ° C./min, clearly appears, and the exothermic amount is 10m
High-speed crystalline copolymerized polyethylene terephthalate resin for molding materials, characterized by J / mg or more. 2. The ethylene terephthalate component is 70 to 90.
% Of copolymerized polyethylene terephthalate,
Casting a solvent solution of copolymerized polyethylene terephthalate having an intrinsic viscosity [η] of 0.5 or more, or
A method for producing a high-speed crystalline polyethylene terephthalate resin for a molding material, which comprises reprecipitation with a non-solvent.