Search

EP-4741457-A1 - POLYESTER RESIN COMPOSITION AND MOLDED ARTICLE THEREOF

EP4741457A1EP 4741457 A1EP4741457 A1EP 4741457A1EP-4741457-A1

Abstract

According to the present invention, there can be provided a polyester resin composition comprising a polyester resin (A) and a dye (B), wherein the polyester resin (A) has a dicarboxylic acid constituent unit and a diol constituent unit, the dicarboxylic acid constituent unit is a terephthalic acid unit and/or a 2,6-naphthalenedicarboxylic acid unit, 5% to 90% by mole of the diol constituent unit is a unit represented by the following general formula (1) or general formula (2), and 5% to 90% by mole of the diol constituent unit is a unit derived from an alicyclic diol, and the dye (B) is a combination of two or more types of dyes each having a structure containing at least two secondary amino groups and at least one benzene ring:

Inventors

  • TAGUWA, KEN
  • MORISHITA, Takami

Assignees

  • MITSUBISHI GAS CHEMICAL COMPANY, INC.

Dates

Publication Date
20260513
Application Date
20240626

Claims (10)

  1. A polyester resin composition comprising a polyester resin (A) and a dye (B), which is characterized in that the polyester resin (A) has a dicarboxylic acid constituent unit and a diol constituent unit, the dicarboxylic acid constituent unit is a terephthalic acid unit and/or a 2,6-naphthalenedicarboxylic acid unit, 5% to 90% by mole of the diol constituent unit is a unit derived from a diol having a cyclic acetal skeleton represented by the following general formula (1) or general formula (2), and 5% to 90% by mole of the diol constituent unit is a unit derived from an alicyclic diol, and the dye (B) is a combination of two or more types of dyes each having a structure containing at least two secondary amino groups and at least one benzene ring: wherein, in the formula (1), R 1 and R 2 each independently represent an aliphatic group containing 1 to 10 carbon atoms, an alicyclic group containing 3 to 10 carbon atoms, or an aromatic group containing 6 to 10 carbon atoms, wherein, in the formula (2), R 1 is the same as that described above, R 3 represents an aliphatic group containing 1 to 10 carbon atoms, an alicyclic group containing 3 to 10 carbon atoms, or an aromatic group containing 6 to 10 carbon atoms.
  2. The polyester resin composition according to claim 1, wherein the dye (B) is a dye of two or more colors selected from the group consisting of C.I. (Color Index) Solvent Blue RR, Solvent Blue 97, Solvent Blue 104, Solvent Violet 36, and Reactive Red 2.
  3. The polyester resin composition according to claim 1, wherein the dye (B) is a dye of two or more types selected from the group consisting of compounds represented by the following formulae (3) to (6):
  4. The polyester resin composition according to any one of claims 1 to 3, which contains the dye (B) in an amount of 3.0 ppm or more and 10 ppm or less.
  5. The polyester resin composition according to any one of claims 1 to 4, wherein the diol having a cyclic acetal skeleton is 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, and the alicyclic diol is 1,4-cyclohexanedimethanol.
  6. The polyester resin composition according to any one of claims 1 to 5, wherein the dicarboxylic acid constituent unit is a 2,6-naphthalenedicarboxylic acid unit.
  7. The polyester resin composition according to any one of claims 1 to 6, wherein the content of polycarbodiimide in the polyester resin composition is less than 0.1% by mass.
  8. A molded product, which uses the polyester resin composition according to any one of claims 1 to 7.
  9. A container, which uses the polyester resin composition according to any one of claims 1 to 8.
  10. A baby bottle, which uses the polyester resin composition according to any one of claims 1 to 9.

Description

Technical Field The present invention relates to a polyester resin composition, and a molded product such as a baby bottle that uses the aforementioned polyester resin composition. Background Art Aromatic saturated polyester resin, in particular, polyethylene terephthalate (hereinafter referred to as "PET" at times), is a resin that provides a well-balanced combination of mechanical performance, solvent resistance, fragrance retention, weather resistance, recyclability, and the like, and it has been widely used mainly for intended uses such as bottles and films. However, PET has drawbacks in terms of crystallinity and heat resistance. That is to say, regarding crystallinity, since PET has high crystallinity, PET whitens due to crystallization and loses its transparency when it is used to produce thick molded bodies or sheets. Moreover, regarding heat resistance, since the glass transition temperature of PET is approximately 80°C, it can be said that PET is unsuitable for intended uses requiring high heat resistance and high transparency, such as products used inside automobiles, packaging materials for imports and exports, food packaging materials for retort treatment or microwave heating, and baby bottles, tableware, etc. for heat sterilization treatment. For this reason, low-crystallinity polyester resins, such as modified PET partially copolymerized with 1,4-cyclohexanedimethanol or modified PET partially modified with isophthalic acid, have been conventionally used for intended uses requiring transparency. However, although such modified PET partially copolymerized with 1,4-cyclohexanedimethanol and modified PET partially modified with isophthalic acid are improved in terms of transparency, compared to PET, the glass transition temperature of these resins is around 80°C, making them poor in heat resistance. Moreover, regarding areas requiring heat resistance, polyester resins such as polyethylene 2,6-naphthalate (hereinafter referred to as "PEN" at times) and poly(1,4-cyclohexanedimethylene terephthalate), which have a high glass transition temperature, have been used. However, although PEN and poly(1,4-cyclohexanedimethylene terephthalate) have improved in terms of heat resistance, they have high crystallinity and poor transparency. Furthermore, as a polyester resin that has improved the heat resistance of PET and PEN while having high transparency, a polyester resin containing a diol having a cyclic acetal skeleton has been proposed (Patent Literatures 1 and 2). Such a polyester resin can be utilized for intended uses, in which transparency and heat resistance are required. However, in the field of baby bottles, etc., in which boiling sterilization had been conventionally used, the use of home UV sterilizers has become widespread in recent years, and UV sterilization has become a common sterilization method. Further, in response to growing societal needs such as ESG and SDGs, the packaging of baby bottles and other items is increasingly becoming simpler (from paper boxes to simple shrink film only). Citation List Patent Literature Patent Literature 1: JP Patent Publication (Kokai) No. 2017-105873 APatent Literature 2: International Publication WO2020/218324 Summary of Invention Technical Problem For this reason, it is required to impart UV resistance to polyester resins, so as to suppress deterioration such as a decrease in strength and deterioration such as color change due to UV irradiation by UV sterilizers, etc., or exposure to fluorescent lights and sunlight when displayed in stores. Furthermore, when UV resistance is imparted, it is also required not to impair (or even to improve) the color tone of thermoplastic polyester resins. Solution to Problem As a result of intensive studies, the present inventors have found that, by combining two or more types of dyes each having a specific structure with a polyester resin having a predetermined composition, it is possible to impart UV resistance to the polyester resin without deteriorating its color tone, thereby completing the present invention. Specifically, the present invention includes the following aspects. [1] A polyester resin composition comprising a polyester resin (A) and a dye (B), which is characterized in that the polyester resin (A) has a dicarboxylic acid constituent unit and a diol constituent unit,the dicarboxylic acid constituent unit is a terephthalic acid unit and/or a 2,6-naphthalenedicarboxylic acid unit,5% to 90% by mole of the diol constituent unit is a unit derived from a diol having a cyclic acetal skeleton represented by the following general formula (1) or general formula (2), and 5% to 90% by mole of the diol constituent unit is a unit derived from an alicyclic diol, andthe dye (B) is a combination of two or more types of dyes each having a structure containing at least two secondary amino groups and at least one benzene ring: wherein, in the formula (1), R1 and R2 each independently represent an aliphatic group containing