JP-7855899-B2 - Polyalkylene ether glycol copolymer polyester, molded article

Inventors

• 岡部 未紗子
• 渡辺 美聡
• 中嶋 康子
• 伊藤 志成
• 近藤 晃
• 下川 隆一

Assignees

• 三菱ケミカル株式会社

Dates

Publication Date

20260511

Application Date

20220331

Claims (6)

1. It has structural units derived from dicarboxylic acids, structural units derived from diols, and structural units derived from polyalkylene ether glycol represented by the following formula (1), The structural unit derived from the polyalkylene ether glycol represented by the following formula (1) has a structural unit derived from a polyalkylene ether glycol component consisting of two or more diols, A polyalkylene ether glycol copolymer polyester having a number-average molecular weight of 500 to 5,000 for structural units derived from the polyalkylene ether glycol. HO-(R 1 -O) n -(R 2 -O) m -H (1) (In the formula, R1 is a hydrocarbon group of a dimeric diol containing 36 to 44 carbon atoms, which is normally present in alcohols obtained by reducing cyclic and acyclic dimeric acids obtained by dimerizing unsaturated fatty acids, or an alkylene group consisting of 2 to 6 carbon atoms; R2 represents an alkylene group having 6 to 18 carbon atoms. n and m are in the range of 500 to 5,000 number-average molecular weights of structural units derived from the polyalkylene ether glycol represented by formula (1), and n/(n+m) is between 0.1 and 0.7. )
2. The polyalkylene ether glycol copolymer polyester according to claim 1, wherein the content of structural units derived from the polyalkylene ether glycol in the polyalkylene ether glycol copolymer polyester is 10 to 80% by mass.
3. The polyalkylene ether glycol copolymer polyester according to claim 1 or 2, wherein the structural units derived from the dicarboxylic acid include structural units derived from aromatic dicarboxylic acids or alicyclic dicarboxylic acids.
4. The polyalkylene ether glycol copolymer polyester according to any one of claims 1 to 3, wherein the structural unit derived from the diol includes a structural unit derived from an aliphatic diol having 2 to 8 carbon atoms.
5. The polyalkylene ether glycol copolymer polyester according to any one of claims 1 to 4, wherein the polyalkylene ether glycol component comprising the two or more diols comprises a polyalkylene ether glycol having structural units derived from a diol component having 8 to 15 carbon atoms and structural units derived from a diol component having 36 to 44 carbon atoms.
6. A molded article comprising a polyalkylene ether glycol copolymer polyester according to any one of claims 1 to 5 .

Description

This invention relates to a polyalkylene ether glycol copolymerized polyester obtained by copolymerizing polyalkylene ether glycol, and a molded article containing the copolymerized polyester. Polyester resins occupy an important industrial position due to their excellent mechanical and chemical properties. For example, aromatic polyesters such as polyethylene terephthalate and polybutylene terephthalate (PBT) are resins with excellent heat and chemical resistance. Due to their ease of molding and cost-effectiveness, they are widely used in extrusion molding and injection molding applications for fibers, films, sheets, bottles, electrical and electronic components, automotive parts, and precision instrument parts. However, in recent years, there has been a demand for polyesters that maintain their basic properties while adding new functions such as flexibility, low-temperature properties, and impact resistance. Furthermore, there is a desire for the efficient production of such polyesters. For example, in the case of PBT, numerous copolymerization components have been investigated to improve its physical properties, but the number of cases that have reached practical application has been extremely limited. This is because copolymerization components tend to be randomly incorporated into the PBT chain, causing a decrease in the melting point and crystallization rate of PBT, thus counteracting the advantages of PBT, such as its high melting point and easy moldability. On the other hand, when copolymer components are incorporated into the PBT chain in a block-like manner, the effect of melting point depression corresponding to the introduction ratio is small, so various physical properties can be modified without lowering the melting point of PBT. Polytetramethylene glycol (hereinafter referred to as "PTMG") is known as a typical copolymer component (Patent Document 1). That is, a technique is known in which flexibility can be imparted to PBT by copolymerizing PTMG, which is a soft segment, with crystalline PBT as a hard segment, and this is now widely used in the film field and other areas. As an example, Patent Document 2 describes an example in which a PTMG copolymer with a PTMG content of 10% by weight is used as one layer of a laminated film (Patent Document 2). However, PTMG segments have a drawback: when subjected to temperatures exceeding the appropriate range, they generate volatile, flammable, and harmful tetrahydrofuran (THF) as a decomposition gas. This characteristic leads to negative consequences in terms of physical properties, such as a decrease in the thermal decomposition temperature of the resin and the generation of decomposition gases. Furthermore, in terms of processing, it causes problems during melt molding, as the generated THF bubbles become mixed into the resin. Patent Document 3 describes an example of a copolymerized polyalkylene ether glycol polyester that exhibits excellent thermal stability, meaning that no harmful gases are generated even at high temperatures, through copolymerization of polyalkylene ether glycol with long alkylene chains and polyester. However, it has been difficult to achieve both thermal stability and mechanical properties such as flexibility, and improvements for practical use have been needed. Japanese Unexamined Patent Publication No. 49-31795Japanese Patent Publication No. 2007-307708Japanese Patent Publication No. 2020-147744 The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is just one example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist of the invention. In this specification, a numerical range expressed using "~" means a range that includes the numbers written before and after "~" as the lower limit and upper limit. Furthermore, in this specification, "main component" means that it constitutes 70 mol% or more of the component. For example, "dicarboxylic acid component containing terephthalic acid as the main component" means that 70 mol% or more of the total acid components constituting the polyester are terephthalic acid components. Furthermore, the term "dicarboxylic acid component" is also used to mean "a structural unit derived from a dicarboxylic acid component that is incorporated into a polyalkylene ether glycol copolymer polyester." The same applies to "diol component" and "polyalkylene ether glycol component." Furthermore, the polyalkylene ether glycol copolymer ester of the present invention may be used as a composition mixed with a polyester that does not contain the polyalkylene ether glycol component. <Polyalkylene ether glycol copolymer polyester> The polyalkylene ether glycol copolymer polyester of the present invention has structural units derived from a dicarboxylic acid, structural units derived from a diol, and structural units derived