JPH11170329A - Method for extrusion molding of polyethylene terephthalate resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a crystallization speed by lowering crystallization temp. without lowering transparency in a method for the extrusion molding of a polyethylene terephthalate resin. SOLUTION: When a particulate polyethylene terephthalate resin is supplied to an extrusion molding machine and melted and kneaded to be subjected to extrusion molding in a method for the extrusion molding of the polyethylene terephthalate resin, the particulate resin is brought into contact with a member comprising a crystallizable thermoplastic resin different from this resin at the time of adding a very small amt. of the crystallizable thermoplastic resin to the particulate resin. This crystalline thermoplastic resin is pref. a polyolefinic resin such as a polythylenic resin, a polypropylene resin or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extruding a polyethylene terephthalate resin,
The present invention relates to a method for extruding a polyethylene terephthalate resin which is useful for molding a magnetic storage film or the like, in which the crystallization temperature is lowered without lowering the transparency.

[0002]

2. Description of the Related Art Conventionally, polyethylene terephthalate resin has attracted attention due to its excellent mechanical properties and chemical properties, as well as its excellent transparency, gas barrier properties, safety and health, and the like. It has shown remarkable growth for various packaging, magnetic storage, refrigerator inner boxes, etc.

[0003] These polyethylene terephthalate resin films and sheets are usually extruded, quenched and then reheated, then re-heated, biaxially stretched, and heat-treated to impart heat resistance to crystallization. Promoting is being done. However, since polyethylene terephthalate resin has a low crystallization rate, there is a problem that such heat treatment and the like require time, and improvement thereof has been strongly desired.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present invention provides a method for extruding a polyethylene terephthalate resin in which the crystallization speed is improved by lowering the crystallization temperature without lowering the transparency. The purpose is to do.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object. That is, the present invention provides a method for supplying granules of polyethylene terephthalate resin to an extruder, melt-kneading and extruding the granules. The gist of the present invention is a method of extruding a polyethylene terephthalate resin in which a small amount of the crystalline thermoplastic resin is contained by contacting a member made of a crystalline thermoplastic resin different from the resin when the resin is supplied.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the polyethylene terephthalate resin includes a dicarboxylic acid unit mainly composed of terephthalic acid or its alkyl (about 1 to 4 carbon atoms) ester and a glycol unit mainly composed of ethylene glycol. The oxyethylene oxyterephthaloyl unit preferably accounts for at least 80 equivalent% of all the constituent units. Further, the content of diethylene glycol units is 1 to 4 mol% based on all glycol units.
Is preferably within the range.

The dicarboxylic acid units other than terephthalic acid and its alkyl ester include, for example, phthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenoxyethanedicarboxylic acid,
Aromatic dicarboxylic acids such as 4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid, and malonic acid , Succinic acid, adipic acid, azelaic acid, aliphatic dicarboxylic acids such as sebacic acid, and as a glycol unit other than ethylene glycol, for example, propylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, Aliphatic glycols such as decamethylene glycol, neopentyl glycol and diethylene glycol, 1,1-cyclohexane dimethylol,
Alicyclic glycols such as 4-cyclohexane dimethylol, 4,4'-dihydroxybiphenyl, 2,2-bis (4'-hydroxyphenyl) propane, 2,2-bis (4'-β-hydroxyethoxyphenyl) propane ,
Bis (4-hydroxyphenyl) sulfone, bis (4-
aromatic glycols such as (β-hydroxyethoxyphenyl) sulfonic acid, and further one or more kinds of, for example, hydroxycarboxylic acids and alkoxycarboxylic acids such as p-hydroxybenzoic acid and p-β-hydroxyethoxybenzoic acid; Used as a copolymer component.

The raw materials containing these dicarboxylic acid units containing terephthalic acid or its alkyl ester as a main component, and glycol units containing ethylene glycol as a main component,
According to a conventional method, an esterification reaction or a transesterification reaction is carried out at a temperature of about 240 to 280 ° C. and a pressure of about 1 to 3 kg / cm ^{2 in} the presence of an esterification catalyst or a transesterification catalyst such as a metal compound such as manganese. After being converted to bis (β-hydroxyethyl) terephthalate and / or an oligomer thereof, the reaction is carried out in the presence of a polycondensation catalyst such as a metal compound such as germanium and a stabilizer such as a phosphorous compound such as phosphoric acid.
Melt polycondensation is performed at a temperature of about 00 ° C. and a pressure of about 500 to 0.1 mmHg to form a polymer, which is drawn out in a strand shape from a draw-out port provided at the bottom of the melt polymerization tank, and then cut by a cutter. Into a chip, pellet, or spherical particle, and the granular polymer obtained by melt polycondensation is usually 120 to 20 particles.
After pre-crystallization by heating at a temperature of about 0 ° C. for 1 minute or more, 190 to 230 ° C. under a flow of an inert gas such as nitrogen.
Solid-state polymerization is performed at a temperature of about 1 kg / cm ² to a pressure of about ¹⁰ mmHg for 1 to 50 hours to obtain a granular polyethylene terephthalate resin.

In the present invention, a crystalline thermoplastic resin different from the resin constituting the member for bringing the granular material of the polyethylene terephthalate resin into contact at the time of supply to an extruder is typically a polyolefin. Resin,
Polyamide-based resins and the like can be mentioned.

As the polyolefin resin, for example, ethylene, propylene, butene-1, etc.
About 8 α-olefin homopolymers, those α-olefins, and ethylene, propylene, butene-1,3-
Other α-olefins having about 2 to 20 carbon atoms such as methylbutene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, decene-1 and the like, vinyl acetate, vinyl chloride, acrylic acid , Methacrylic acid, acrylic acid ester, methacrylic acid ester, copolymers with vinyl compounds such as styrene, and the like. Specifically, for example, low-, medium-, and high-density polyethylene (branched or linear) Ethylene homopolymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-4-
Methylpentene-1 copolymer, ethylene-hexene-1
Ethylene resins such as copolymer, ethylene-octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-ethyl acrylate copolymer Propylene resins such as propylene homopolymer, propylene-ethylene copolymer, propylene-ethylene-butene-1 copolymer, and butene-1 homopolymer, butene-1-ethylene copolymer, butene-1 Butene-1 resin such as propylene copolymer;

Examples of the polyamide resin include lactam polymers such as butyrolactam, δ-valerolactam, ε-caprolactam, enantholactam, ω-laurolactam, 6-aminocaproic acid, 11-aminoundecanoic acid, and the like. Polymers of aminocarboxylic acids such as 12-aminododecanoic acid, hexamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, undecamethylenediamine, 2,2,4- or 2,4,4-trimethylhexa Aliphatic diamines such as aliphatic diamines such as methylene diamine, 1,3- or 1,4-bis (aminomethyl) cyclohexane and bis (p-aminocyclohexylmethane), and aromatic compounds such as m- or p-xylylenediamine Diamine units such as aromatic diamines, glutaric acid and adipine , Suberic acid, polycondensates of aliphatic dicarboxylic acids such as sebacic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, terephthalic acid, and dicarboxylic acid units and aromatic dicarboxylic acids such as isophthalic acid,
And copolymers thereof. Specific examples thereof include nylon 4, nylon 6, nylon 7, nylon 8, nylon 9, nylon 11, nylon 12, nylon 66, nylon 69, nylon 610, and nylon 61.
1, nylon 612, nylon 6T, nylon 6I, nylon MXD6, nylon 6/66, nylon 6/61
0, nylon 6/12, nylon 6 / 6T, nylon 6
I / 6T and the like.

In the present invention, when the polyethylene terephthalate resin granules are supplied to an extruder, melt-kneaded and extruded, the particles are brought into contact with the member made of the crystalline thermoplastic resin during the supply. A polyethylene terephthalate resin is extruded by adding a small amount of a thermoplastic resin.

As the members and the contact method at this time, it is preferable that particles of the polyethylene terephthalate resin are brought into collision with the members in a space where the members made of the crystalline thermoplastic resin are present. For example, a part of the pipe for feeding the polyethylene terephthalate resin granules to the extruder hopper is made of a crystalline thermoplastic resin, or the crystalline thermoplastic resin is lined, or a rod-like or A method of supplying a granular material of polyethylene terephthalate resin, for example, by installing a member made of a crystalline thermoplastic resin such as a net-like material. The contact time of the polyethylene terephthalate resin particles with the above-mentioned member is usually very short, about 0.01 to 1 second, but the polyethylene terephthalate resin can contain a trace amount of a crystalline thermoplastic resin.

In the present invention, the content of the crystalline thermoplastic resin in the polyethylene terephthalate resin is preferably 0.1 to 100 ppb with respect to the total amount of the polyethylene terephthalate resin and 1 to 5 ppb.
Particularly preferred is 0 ppb. When the content is less than the above range, the effect of lowering the temperature of crystallization as a resin becomes insufficient, and when the content exceeds the above range, the transparency of the resin tends to be impaired. The intrinsic viscosity of the polyethylene terephthalate resin containing the crystalline thermoplastic resin is 0.6 to 1.0 dl / as a value measured at 30 ° C. in a mixed solvent of phenol / tetrachloroethane (weight ratio 1/1). g is preferred.

The polyethylene terephthalate resin supplied by the above method is extruded, for example, formed into a sheet, reheated, and then biaxially stretched into a film. Extrusion molding conditions at that time are in a range usually employed, for example, a cylinder temperature of 240 to
300 ° C., screw rotation speed 40-300 rpm, discharge pressure 40-140 kg / cm ² , cooling drum temperature 5-4
Molding can be performed at a temperature of 0 ° C. or the like.

The polyethylene terephthalate resin produced by the extrusion molding method of the present invention can lower the crystallization temperature during molding. Specifically, the temperature of the molded resin is increased by differential scanning calorimetry. The temperature is preferably from 145 to 170 ° C, particularly preferably from 150 to 165 ° C. Here, the elevated crystallization temperature refers to the top temperature of the crystallization peak observed during the course of heating from room temperature to 285 ° C. at a rate of 20 ° C./min with a differential scanning calorimeter. .

[0017] Among the molded articles obtained by the above extrusion molding method,
In the present invention, the unstretched sheet that has been extruded and quenched is reheated, then biaxially stretched, and is suitable for forming a film by further heat treatment, and is particularly useful for forming a magnetic memory film and the like. .

[0018]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. Example 1 13.0 kg of terephthalic acid and 5.8 of ethylene glycol
2 kg of a slurry is prepared, and 0.30 kg of bis (2-hydroxyethyl) terephthalate is added in advance to prepare a slurry.
The mixture was sequentially supplied to the esterification tank maintained at a temperature of 50 ° C. over 4 hours. After completion of the supply, the esterification reaction was allowed to proceed for 1 hour, and then half of the mixture was transferred to a polycondensation tank, and phosphoric acid was added at 0.9%.
1 g and 0.92 g of germanium dioxide,
The temperature was gradually increased from 278 ° C. to 278 ° C., the pressure was gradually reduced from normal pressure, and the polycondensation reaction was carried out for 3 hours while maintaining the pressure at 0.5 mmHg. The strand was drawn out into a strand, cooled with water, and cut with a cutter to obtain an elliptic cylindrical polyethylene terephthalate resin chip.

When the obtained polyethylene terephthalate resin chips are supplied to an extruder (a single screw extruder having a diameter of 40 mm, manufactured by Mitsubishi Heavy Industries, Ltd.), a SUS having a diameter of 50 mm between the attached hopper and the extruder body is used. A part of the pipe made of low-density polyethylene ("UE320" manufactured by Nippon Polychem Co., Ltd.) was supplied over a length of 0.3 m, and the temperature of each part of the cylinder and the nozzle head was 260
℃, screw rotation speed 200rpm, thickness 500μm
Was extruded. In this case, the polyethylene terephthalate resin sampled from the lower part of the pipe contains 3 ppb of low-density polyethylene, and its intrinsic viscosity is
0.70 dl / g. About the obtained sheet,
The crystallization temperature and transparency of the resin were measured, and the results are shown in Table 1. In addition, the measuring method of each physical property is as follows.

Crystallization temperature Differential scanning calorimeter (manufactured by Seiko Denshi Co., Ltd., “DSC220
C)), the temperature was raised from room temperature to 285 ° C. at a rate of 20 ° C./min, and the top temperature of the crystallization peak observed during the heating (temperature-up crystallization temperature: TC ₁ ) was measured. Transparency haze meter (NDH-300A, manufactured by Nippon Denshoku)
, The haze was measured.

COMPARATIVE EXAMPLE 1 Except that the supply pipe was supplied as it was made of SUS, extrusion was carried out in the same manner as in Example 1 to measure the properties, and the results are shown in Table 1.

[0022]

[Table 1]

[0023]

According to the present invention, it is possible to provide a method for extruding a polyethylene terephthalate resin having an improved crystallization rate by lowering the crystallization temperature without lowering the transparency.

Claims (7)

[Claims] 1. A method for supplying a granular material of polyethylene terephthalate resin to an extruder, melt-kneading and extruding the granular material, wherein at the time of supply, the granular material is brought into contact with a member made of a crystalline thermoplastic resin different from the resin. A method for extruding a polyethylene terephthalate resin, comprising a trace amount of a crystalline thermoplastic resin. 2. The method for extruding a polyethylene terephthalate resin according to claim 1, wherein the member made of the crystalline thermoplastic resin is a pipe for supplying polyethylene terephthalate resin granules. 3. The method for extruding a polyethylene terephthalate resin according to claim 1, wherein the member made of the crystalline thermoplastic resin is a rod or a net placed in a supply path of the polyethylene terephthalate resin granules. 4. The extrusion molding method for a polyethylene terephthalate resin according to claim 1, wherein the crystalline thermoplastic resin is a polyolefin resin. 5. The method for extruding a polyethylene terephthalate resin according to claim 4, wherein the polyolefin resin is a polyethylene resin. 6. The method for extruding a polyethylene terephthalate resin according to claim 4, wherein the polyolefin resin is a polypropylene resin. 7. The method for extruding a polyethylene terephthalate resin according to claim 1, wherein the extruded resin composition has a heated crystallization temperature in a range of 145 to 170 ° C.