JP2007302734A - Resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester-based resin composition with improved heat resistance while keeping transparency of a polyethylene terephthalate, and excellent in extrusion molding property and thermoforming property from a sheet. <P>SOLUTION: The invention relates to the resin composition comprising a mixed resin obtained by compounding a polyester-based resin and a polycarbonate resin with a compounding ratio of 60-40/40-60, and a fatty acid ester as indispensable components, wherein the polyester-based resin is a mixture of the polyethylene terephthalate (A) and a polyester (B) composed of a dicarboxylic acid component composed of terephthalic acid and a diol components composed of a 50-60 mol% of 1, 4-cyclohexane dimethanol and 50-40 mol% of ethylene glycol, having the ratio (A)/(B) of 42-85/58-15. The fatty acid glycerin ester is preferable as the fatty acid ester. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin composition, particularly a polyester-based resin composition that has improved heat resistance while maintaining transparency of polyethylene terephthalate, and is excellent in extrusion moldability and thermoformability from a sheet shape.

  Polyethylene terephthalate has excellent transparency and surface gloss, and is widely used in drinking water bottles, food packaging materials, and the like. For this reason, the amount of polyethylene terephthalate discharged from households and the like is increasing, and this is recycled and used as a raw material for textiles, sheets and films.

  However, although polyethylene terephthalate is transparent, it has poor heat resistance and has a problem that it cannot be used in applications requiring heat resistance, such as carrier tapes and carrier trays for transporting electronic components.

  Therefore, it is conceivable to add a polycarbonate resin to polyethylene terephthalate in order to improve heat resistance.

  However, in a sheet / film obtained from a composition in which a polycarbonate resin is blended with polyethylene terephthalate, although improvement in heat resistance is observed, if the sheet is to be thermoformed into a desired shape for use in the carrier tape or the like, the sheet is formed. When heating, the whitening phenomenon due to crystallization of polyethylene terephthalate is observed, and another problem that a desired product cannot be obtained occurs.

  On the other hand, for example, a technique for mixing recycled polyethylene terephthalate and a specific polycarbonate resin has been proposed. (Patent Document 1)

  However, when the resin composition containing such polyethylene terephthalate is formed into a sheet by extrusion, the following problems occur. In the extrusion molding method, usually, a molten resin is extruded from a T-die and passed through a pair of metal rolls set in advance with a predetermined clearance to form a sheet, but polyethylene terephthalate has a heavy weight. There is a problem that oligomers from the condensation stage remain, and the remaining oligomers sublimate from the die of the T die, adhere to the metal roll, and are cooled and fixed.

  Such a metal roll to which the oligomer component is fixed reduces the roll releasability of the molten resin passing therethrough, and lowers the transparency and surface gloss of the sheet / film. In addition, in the sheet formed with the roll releasability deteriorated in particular, the contact portion and the non-contact portion of the roll appear alternately, and the traces caused by the thickness unevenness in the flow direction (depending on the roll) A trace is taken). When it is formed by a secondary forming method such as a vacuum forming method, which is a subsequent process, traces taken by the roll become more prominent, and the quality and appearance of the molded product are significantly reduced. .

  The present invention has been made in view of the above problems, and a polyester-based resin composition having improved heat resistance while maintaining the transparency of polyethylene terephthalate, and excellent in extrusion moldability and thermoformability from a sheet shape. The purpose is to provide.

JP 2005-324356

  The present inventor has found that the above problem can be solved by adding a polycarbonate resin, a specific polyester resin, and a specific compounding agent as a lubricant component to polyethylene terephthalate.

  That is, the invention according to claim 1 is an essential component comprising a mixed resin in which a polyester resin and a polycarbonate resin are blended, and a blending ratio of the polyester resin and the polycarbonate resin is 60 to 40/40 to 60, and a fatty acid ester. The polyester resin comprises polyethylene terephthalate (A) and a dicarboxylic acid component composed of terephthalic acid, 50 to 60 mol% of 1,4-cyclohexanedimethanol and 50 to 40. A resin composition comprising a polyester (B) composed of a diol component composed of mol% ethylene glycol, wherein (A) / (B) is 42 to 85/58 to 15 The gist is the thing.

  The invention according to claim 2 is summarized in the resin composition according to claim 1, wherein the fatty acid ester is a fatty acid glycerin ester in which an alcohol constituting the ester is glycerin.

  The invention according to claim 3 is characterized in that the blending ratio of the mixed resin and the fatty acid ester is 0.01 to 1.0 part by weight with respect to 100 parts by weight of the mixed resin. The gist is the resin composition according to claim 1 or 2.

  The resin composition of the present invention has improved heat resistance while maintaining the transparency of polyethylene terephthalate by blending a polycarbonate resin with a polyester resin comprising polyethylene terephthalate (A) and polyester (B). It becomes.

  Further, by mixing the mixed resin with a fatty acid ester, the oligomer remaining in the polyethylene terephthalate (A) is not fixed to the metal roll even by extrusion, and the sheet has excellent transparency and surface gloss. And the sheet is excellent in thermoformability.

  Thus, the resin composition of the present invention can effectively use polyethylene terephthalate collected from homes and the like, and has an effect that it can be used for a wider range of applications.

  The polyester-based resin of the present invention comprises polyethylene terephthalate (A), a dicarboxylic acid component composed of terephthalic acid, a diol component composed of 50 to 60 mol% of 1,4 cyclohexanedimethanol and 50 to 40 mol% of ethylene glycol. And (A) / (B) in the range of 42 to 85/58 to 15.

  Polyethylene terephthalate (A) is made from recycled materials such as drinking water bottles, food packaging materials, etc. once discarded as waste from households in addition to commercially available raw materials. So-called recycled raw materials used as raw materials can also be used.

  In this polyethylene terephthalate (A), if the ratio to the polyester resin exceeds 85%, the transparency is impaired. In addition, when thermoforming a sheet-shaped material, the crystallization of polyethylene terephthalate proceeds and the sheet solidifies or a whitening phenomenon is observed if it is preheated. It is not preferable. On the other hand, if it is less than 42%, during thermoforming, the drawdown of the sheet tends to increase during heating, and bridges are likely to occur in the thermoformed product, which is not preferable.

  The resin composition in the present invention is obtained by blending and mixing the polyester resin and the polycarbonate resin, and the blending ratio of the polyester resin and the polycarbonate resin is set at a ratio of 60 to 40/40 to 60. There is a need. If the ratio of the polycarbonate resin is less than 40%, the heat resistance is inferior, which is not preferable. On the other hand, if it exceeds 60%, when the sheet is thermoformed into a desired shape, the time required for heating becomes long, it is difficult to suppress crystallization and whitening, and it is difficult to obtain a thermoformed product, which is not preferable.

  Furthermore, in this invention, fatty acid ester needs to be mix | blended with this mixed resin as an essential component. By blending the fatty acid ester, when the sheet is formed by extrusion, the oligomer remaining in the polyethylene terephthalate (A) is not fixed to the metal roll, and the sheet is excellent in transparency and surface glossiness. No trace is taken by the roll, and the thermoformability is excellent.

  As the fatty acid ester, any ester obtained by reacting a fatty acid with an alcohol can be used without particular limitation. For example, examples of fatty acids include palmitic acid, stearic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, and montanic acid. As the alcohol, any known alcohol such as lauryl alcohol, 1,2-butanediol, 1,3-butanediol, and 2,3-butanediol can be used.

  Among them, the fatty acid ester of the present invention is preferably a fatty acid glycerin ester in which the alcohol constituting the ester is glycerin. For example, fatty acid glycerin esters include fatty acid monoglycerides, fatty acid diglycerides, fatty acid triglycerides, hydrogenated castor oil, and the like.

  As a compounding quantity of fatty acid ester, it is preferable to set it as 0.01-1.0 weight part with respect to 100 weight part of the said mixed resin. If it is less than 0.01 part by weight, it may be impossible to prevent the oligomer remaining in the polyethylene terephthalate from sticking to the metal roll during extrusion molding of the resin composition. That is, in that case, the transparency and surface gloss of the sheet / film are lowered, and the thickness unevenness is increased. If it exceeds 1.0 part by weight, the viscosity of the resin composition will be too low, and the stability in extrusion molding will be impaired, which is not preferable.

  As described above, the resin composition of the present invention can be made into a sheet-shaped product by ordinary extrusion molding, and a molded product having a desired shape can be obtained by thermoforming such as vacuum molding. .

  Specific examples and comparative examples of the present invention will be described. The raw materials used are as follows.

Polycarbonate resin: trade name “L-1250WQ”, polyethylene terephthalate (A) manufactured by Teijin Chemicals Ltd. (A): recycled polyethylene terephthalate polyester from recovered bottle (B): trade name “SKYGREEN J2003”, fatty acid ester (1 manufactured by SK Chemical Co., Ltd.) ): Hydrogenated castor oil, trade name “K-3 wax 500”, fatty acid ester manufactured by Kawaken Fine Chemical Co., Ltd. (2): fatty acid monoglyceride, trade name “Riquemar S 100A”, manufactured by Riken Vitamin Co., Ltd.

<Examples 1-5, Comparative Examples 1-9>
The above raw materials were mixed at the blending ratios shown in Tables 1 and 2, and extruded to obtain a sheet having a thickness of 0.5 mm. About the obtained sheet | seat, extrusion moldability was evaluated by confirming the surface external appearance visually, and transparency was evaluated by measuring a haze according to ASTMD1003. As the evaluation of the extrusion moldability, the case where no trace was observed by the roll on the sheet surface was evaluated as “◯”, and the case where the trace was observed was evaluated as “X”. As for transparency, those having a haze of 30 or less were evaluated as good, and those exceeding 30 were evaluated as having poor transparency. For the evaluation of thermoformability, the obtained sheet was vacuum-formed at a heater temperature of 400 to 420 ° C. using a male mold having a double expansion ratio, and the one that was kept transparent and vacuum-formed was evaluated as ○, vacuum. △ can be molded but has a bridge, or the surface of the molded product is traced by a roll, crystallization progresses and solidifies and cannot be vacuum formed, or crystallizes even if it can be vacuum formed to some extent Those with whitening due to were evaluated as x. Separately, a test piece for the deflection temperature under load (JIS K7191) was produced by injection molding the above-mentioned blended raw material, and the same temperature was measured. When the deflection temperature under load was 80 ° C. or lower, the heat resistance was good, and when it was lower than 80 ° C., the heat resistance was evaluated as poor. These results are shown in Tables 1 and 2.

  As is clear from Tables 1 and 2, in Examples 1 to 5 according to the present invention, the extruded sheet showed good extrudability without being traced by a roll. Further, the obtained sheet could be thermoformed by vacuum forming, and the appearance of the molded product was good. It was also excellent in transparency and heat resistance. On the other hand, in Comparative Examples 1 to 4 in which the ratio of the polyethylene terephthalate (A) and the polyester (B) deviates from the technical scope of the present invention, both thermoformability and transparency are inferior. Met. Moreover, in Comparative Examples 5-8 in which the blending ratio of the polyester resin and the polycarbonate resin is outside the technical scope of the present invention, the thermoformability or heat resistance was poor. Further, in Comparative Example 9, which is outside the technical scope of the present invention in which no fatty acid ester is added, both the sheet after extrusion molding and the molded product after vacuum molding show traces taken by rolls, and extrusion molding. The results were inferior in both heat resistance and thermoformability.

Claims (3)

  A polyester resin and a polycarbonate resin are blended, and a resin composition having a blending ratio of the polyester resin and the polycarbonate resin of 60 to 40/40 to 60 and a fatty acid ester as essential components, The polyester resin is a diol composed of polyethylene terephthalate (A) and a dicarboxylic acid component composed of terephthalic acid, 50 to 60 mol% 1,4-cyclohexanedimethanol and 50 to 40 mol% ethylene glycol. A resin composition comprising a polyester (B) composed of components, wherein (A) / (B) is 42 to 85/58 to 15.   The resin composition according to claim 1, wherein the fatty acid ester is a fatty acid glycerin ester in which an alcohol constituting the ester is glycerin.   The blending ratio of the mixed resin and the fatty acid ester is 0.01 to 1.0 part by weight of the fatty acid ester with respect to 100 parts by weight of the mixed resin. The resin composition in any one.