KR20040099834A - Polyethyleneterephthalate copolymer having an outstanding rate of crystallization and preparation thereof - Google Patents

Abstract

PURPOSE: A polyethylene terephthalate copolymer excellent in velocity of crystallization is provided, which improves the problem of separation to the outside at a high temperature and has a surface-improving effect. And a process is also provided to produce the polyethylene terephthalate copolymer. CONSTITUTION: The polyethylene terephthalate copolymer is produced by the process comprising the steps of: transesterifying dimethyl terephthalate or terephthalic acid and ethylene glycol with a metal catalyst at 130-230deg.C; adding 0.5-30pts.wt.(based on the dimethyl terephthalate or the terephthalic acid of 100pts.wt.) of a dimerized fatty acid(formula 1) to perform an additional esterification; polycondensing the resultant under a high temperature and high vacuum. The polyethylene terephthalate copolymer has a glass transition temperature of 20deg.C or higher and a crystallization range of 100-160deg.C. In the formula, X is a linear, aliphatic ring, or aromatic ring type hydrocarbon group and R1, R2, R3, and R4 are C5-C10 alkyl groups or alkylene groups or C5-C10 alkyl groups or alkylene groups of which the terminals are substituted by -COOH, wherein the total maximum carbon number of R1, R2, R3, and R4 is 16-52 and at least one of R1, R2, R3, and R4 has -COOH on the terminal.

Description

Polyethylene terephthalate having excellent crystallization rate and its preparation method {Polyethyleneterephthalate copolymer having an outstanding rate of crystallization and preparation}

The present invention relates to a copolymerized polyethylene terephthalate, and more particularly, to a copolymerized polyethylene terephthalate excellent in crystallization rate and a method for producing the same.

In the case of general thermoplastic polyester, for example, polyethylene terephthalate, it is widely used for films or fibers due to its excellent physical and chemical properties, but generally has a disadvantage of poor hygroscopicity, flame retardancy, and dyeability.

In particular, since the crystallization rate is low and the moldability is poor, the use value of plastic molding material is low.

The commercialization of such molding resin was developed in 1966 under the trade name FR-PET by reinforcing glass fibers at Teijin, Japan. Such polyethylene terephthalate has been widely used in electrical and electronic materials due to its excellent heat resistance, dimensional stability, electrical properties, and appearance gloss, but has a disadvantage of low impact strength due to low crystallization rate and a high temperature mold of 130 ° C or higher.

As such, the unmodified polyethylene terephthalate has a low crystallization rate, making it difficult to economically obtain a product having stable performance by injection molding. Therefore, in order to use polyethylene terephthalate as an injection molding material, it is necessary to improve the crystallization rate. In order to improve such crystallization, there are a method of adding crystal nuclei and a method of adding a plasticizer.

As such a technique, Japanese Patent Application Laid-open No. 44-7542 has suggested a role of a nucleating agent of a polymerization catalyst insoluble in polyethylene oxide, inorganic substance, organic acid salt, clay, and the like. In particular, in the study of a nuclear agent with a greater effect, Japanese Patent Application Laid-open No. 56-14137 also proposed a nucleating role of alkali metals or alkaline earth metals of organic sulfonic acid.

In addition, in order to speed up the crystallization at low temperature, a method of adding a plasticizer during compounding has also been studied. As a kind of plasticizer, neopentyl glycol dibenzoate as an ester compound, a sorbitan derivative, an epoxy compound, etc. are proposed as an ester compound in Japanese Patent Application Laid-Open No. 54-158452 etc.

In the prior art, the nucleating agent is ineffective, and the dispersibility is poor in manufacturing a molded article, and the improvement of the nucleating agent is required due to deterioration of physical properties due to aggregation, anxiety of numerical stability, and the like. In addition, the plasticizer addition technology could not achieve a substantial crystallization rate because the glass transition temperature was not only lowered but also lowered from the crystallization temperature. In addition, problems such as deterioration of mechanical properties due to a drop in melting point and external detachment due to high temperature during molding are problems requiring improvement.

Therefore, in view of the above problems of the prior art, the glass transition temperature is drastically increased in order to solve the problem of lowering the crystallization temperature of the same width as the glass transition temperature when the plasticizer is added without increasing the crystallization temperature by the nucleating agent. The goal was to develop a composition that minimizes the drop in the crystallization temperature, while specifically reducing the width of the crystallization temperature. Specifically, the width of the copolymerization polyethylene tere is expanded to 100 ° C or more, which is the level of the conventional polyethylene terephthalate. It can be called phthalate. Particularly, due to the participation of stable molecular structure due to copolymerization of the dimerized fatty acid (Dimerized Fatty Acid) component introduced into the composition of the present invention, it is possible to solve the problem of external escape even under high temperature conditions during molding. In addition, the technical task was to improve the surface effect by depressing during spinning or separating from the inner wall of the injection molding machine during molding.

Therefore, according to the present invention, in the copolymerized polyethylene terephthalate, dimethyl terephthalate or terephthalic acid and an acid component comprising 0.5-30 parts by weight of a dimerized fatty acid having a structure of the formula (1) compared to 100 parts by weight of dimethyl terephthalate or terephthalic acid and ethylene glycol Copolymerized polyethylene terephthalate is characterized in that the diol component is copolymerized.

[Formula 1]

(Wherein, X represents a linear, a hydrocarbon group of an aliphatic ring or an aromatic ring type, R1, R2, R3 and R4, or C ₅ ~ C ₁₀ alkyl or alkylene group or the terminal C ₅ ~ C ₁₀ substituted with -COOH Is an alkyl group or an alkylene group, the maximum total carbon number of R1, R2, R3 and R4 is 16 to 52, and at least one of R1, R2, R3 and R4 has -COOH at the terminal)

In addition, the present invention provides a method for producing copolymerized polyethylene terephthalate, comprising the following steps.

Adding dimethyl terephthalate or terephthalic acid and ethylene glycol to a transesterification reactor together with a metal catalyst, and then performing a transesterification reaction by heating to 130 to 230 ° C;

Adding a dimerized fatty acid of Formula 1 as a copolymerization component to the reactor where the transesterification reaction is completed, thereby further adding an esterification reaction; And

Transferring the material produced by the esterification reaction to a polycondensation reactor and polycondensing it under high temperature and high vacuum.

Hereinafter, the present invention will be described in detail.

The present invention is a technique for improving the crystallization rate through the copolymerization composition, specifically, by copolymerizing by adding dimerized fatty acid (Dimerized Fatty Acid) as a copolymerization component, the crystallization temperature with a glass transition temperature of 20 ℃ or more as a stable molecular structure participation The copolymerization polyethylene terephthalate whose crystallization interval which is a difference of 100-160 degreeC is manufactured.

Copolymerized polyethylene terephthalate according to the present invention is a metal catalyst first of the dimethyl terephthalate (hereinafter referred to as "DMT") or terephthalic acid (hereinafter referred to as "TPA") and ethylene glycol (hereinafter referred to as "EG") as the main raw material And then added to the transesterification reactor and heated to 130 ℃ to 230 ℃ to perform a transesterification reaction to prepare bishydroxyethylene terephthalate (hereinafter referred to as "BHET").

In the next step, the esterification reaction is further performed by adding a dimerized fatty acid as a copolymerization component to the reactor where the transesterification reaction is completed. At this time, the amount of the dimerized fatty acid is preferably added to 0.5 to 30.0 parts by weight based on 100 parts by weight of the DMT, if less than 0.5 parts by weight does not cause a change in the glass transition temperature and crystallization temperature can be obtained expected effect There is no problem, and when it exceeds 30.0 parts by weight, there is a concern that the physical property decreases due to excessive copolymerization components, and the glass transition temperature is lowered to 20 ° C or lower, resulting in poor chipping and inherent mechanical strength of polyethylene terephthalate. There is a problem.

In the next step, the material produced by the esterification reaction is transferred to a polycondensation reactor and polycondensed under high temperature and high vacuum to prepare a copolymerized polyethylene terephthalate.

The structure of the dimerized fatty acid (Dimerized Fatty Acid) used as the copolymerization component of the present invention is represented by the following Chemical Formula 1.

(Wherein, X represents a linear, a hydrocarbon group of an aliphatic ring or an aromatic ring type, R1, R2, R3 and R4, or C ₅ ~ C ₁₀ alkyl or alkylene group or the terminal C ₅ ~ C ₁₀ substituted with -COOH Is an alkyl group or an alkylene group, the maximum total carbon number of R1, R2, R3 and R4 is 16 to 52, and at least one of R1, R2, R3 and R4 has -COOH at the terminal)

Representative compounds of Formula 1 are as follows.

First, the X in Formula 1 has a linear structure.

Second, the X in Formula 1 is an aliphatic ring structure.

Fourth, X in the formula (1) is an aromatic ring structure.

Hereinafter, the present invention will be described in detail based on the preferred embodiments as follows, but the present invention is not limited to the examples.

Example 1

65 parts by weight of EG was added to a transesterification reactor based on 100 parts by weight of DMT, followed by a transesterification reaction in the presence of a divalent metal catalyst to prepare BHET, followed by further esterification by adding 0.5 parts by weight of dimerized fatty acid. It was. At this time, as the divalent metal catalyst, calcium acetate and magnesium acetate are used. The polymer was prepared in a pellet form after the polycondensation reaction of the BHET in the presence of antimony trioxide under high temperature and high vacuum in a conventional PET reaction condition. At this time, a catalyst containing titanium together with antimony trioxide may be used.

DSC was measured for the polymer prepared as described above under the measurement condition of Scan Rate 20 ° C./min, and the results are shown in Table 1.

Example 2

The conditions other than adding 1.0 parts by weight of dimerized fatty acid were carried out in the same manner as in Example 1.

Example 3

The conditions other than the addition of 10 parts by weight of dimerized fatty acid proceeded in the same manner as in Example 1.

Example 4

The conditions other than adding 20 parts by weight of dimerized fatty acid proceeded in the same manner as in Example 1.

Example 5

The conditions other than adding 30 parts by weight of dimerized fatty acid proceeded in the same manner as in Example 1.

Comparative Example 1

The same conditions as in Example 1 were carried out except that no dimerized fatty acid was added.

Comparative Example 2

The conditions other than adding 0.4 parts by weight of dimerized fatty acid proceeded in the same manner as in Example 1.

Comparative Example 3

The conditions other than adding 35 parts by weight of dimerized fatty acid were carried out in the same manner as in Example 1.

[Comparative Example 4]

The conditions other than adding 40 parts by weight of dimerized fatty acid proceeded in the same manner as in Example 1.

Glass Transition Temperature Tg (℃) Crystallization Temperature Tc (℃) Crystallization section △ (Tc-Tg) Example 1 71 175 104 Example 2 65 174 109 Example 3 54 172 118 Example 4 37 161 124 Example 5 22 158 156 Comparative Example 1 75 175 100 Comparative Example 2 75 175 100 Comparative Example 3 18 150 132 Comparative Example 4 16 143 127

※ Thermal analysis data measurement

① Device Model: PERKIN ELMER DSC Series 7

② Measuring condition: Glass transition temperature (Tg) is measured by heating at 25 ℃ to 280 ℃ with scan speed of 20 ℃ / min, waiting for 5 minutes at 280 ℃ and then scanning at 280 ℃ to 25 ℃ with 20 ℃ / min scan rate. Measure the crystallization temperature (Tc) while cooling to.

As described above, the copolymerized polyethylene terephthalate obtained by the present invention has a stable molecular structure participation due to copolymerization of the dimerized fatty acid component to be added, it is possible to solve the problem of external escape under high temperature conditions during molding, The dimerized fatty acid component acts as a conventional lubricant, and also has a surface improvement effect by separation from the spinneret during spinning or separation from the inner wall of the injection molding machine.

Claims (4)

In the copolymerized polyethylene terephthalate, dimethyl terephthalate or terephthalic acid and a diol component composed of ethylene glycol and an acid component consisting of 0.5 to 30 parts by weight of a dimerized fatty acid having a structure of the formula (1) relative to 100 parts by weight of the dimethyl terephthalate or terephthalic acid are copolymerized. Copolymerized polyethylene terephthalate, characterized in that: [Formula 1] (Wherein, X represents a linear, a hydrocarbon group of an aliphatic ring or an aromatic ring type, R1, R2, R3 and R4, or C ₅ ~ C ₁₀ alkyl or alkylene group or the terminal C ₅ ~ C ₁₀ substituted with -COOH Is an alkyl group or an alkylene group, the maximum total carbon number of R1, R2, R3 and R4 is 16 to 52, and at least one of R1, R2, R3 and R4 has -COOH at the terminal) The copolymerization polyethylene terephthalate according to claim 1, wherein the crystallization section, which is a difference in crystallization temperature with a glass transition temperature of 20 ° C or more, is 100 to 160 ° C. The copolymerized polyethylene terephthalate according to claim 1, wherein X in Chemical Formula 1 is any structure selected from the group consisting of linear structure, aliphatic ring structure and aromatic ring structure. Method for producing a copolymerized polyethylene terephthalate, characterized in that it comprises the following steps: Adding dimethyl terephthalate or terephthalic acid and ethylene glycol to a transesterification reactor together with a metal catalyst, and then performing a transesterification reaction by heating to 130 to 230 ° C; Adding a dimerized fatty acid of Formula 1 as a copolymerization component to the reactor where the transesterification reaction is completed, thereby further adding an esterification reaction; And Transferring the material produced by the esterification reaction to a polycondensation reactor and polycondensing it under high temperature and high vacuum.