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EP-4427909-B1 - METHOD OF PRODUCING BLOW-MOLDED PRODUCT, RESIN COMPOSITION, AND PELLETS

EP4427909B1EP 4427909 B1EP4427909 B1EP 4427909B1EP-4427909-B1

Inventors

  • DOI, YOHEI
  • ASHIBE, TSUNENORI

Dates

Publication Date
20260506
Application Date
20240305

Claims (10)

  1. A method for producing a blow-molded article, the method comprising: a step of producing a preform from a resin mixture comprising at least a wax, a thermoplastic polyester and a carbodiimide compound; and a step of blow-molding the preform to produce a blow-molded article, wherein the thermoplastic polyester is at least one selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate, characterized in that the carbodiimide compound is a polycarbodiimide having 2 or more carbodiimide groups in the molecule, and wherein a content of the carbodiimide compound in the resin mixture is 227 to 9,096 parts by mass with respect to 100 parts by mass of the wax.
  2. The method for producing a blow-molded article according to claim 1, wherein the wax is an ester wax.
  3. The method for producing a blow-molded article according to claim 1 or 2, wherein the blow-molded article is a toner bottle.
  4. The method for producing a blow-molded article according to any one of claims 1 to 3, wherein the blow-molded article is a stretch-blow-molded article.
  5. The method for producing a blow-molded article according to claim 4, wherein the preform has a test tube shape, and a step of producing the blow-molded article includes: a step of stretching the preform in a longitudinal direction of the preform by using a stretching rod; and a step of introducing a gas into the preform stretched in the longitudinal direction and stretching the preform in a circumferential direction.
  6. The method for producing a blow-molded article according to any one of claims 1 to 5, wherein the step of producing a preform includes: a step of melt-kneading the resin mixture to form pellets; and a preform molding process of molding the pellets into the preform.
  7. The method for producing a blow-molded article according to claim 6, wherein the preform molding process includes a step of injection molding a melt of the pellets.
  8. The method for producing a blow-molded article according to any one of claims 1 to 5, wherein the step of producing a preform includes: a step of melt-kneading the wax and the thermoplastic polyester to form first pellets; a step of melt-kneading the carbodiimide compound and other thermoplastic polyesters to form second pellets; and a preform molding process to mold a pellet mixture of the first pellets and the second pellets into the preform.
  9. The method for producing a blow-molded article according to claim 8, wherein the preform molding process includes a step of injection molding the melt of the pellet mixture.
  10. The method for producing a blow-molded article according to claim 8, wherein a content of the carbodiimide compound in the second pellets is 1,364 to 9,096 parts by mass with respect to 100 parts by mass of the wax comprised in the first pellets.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present disclosure relates to a method of producing a blow-molded article. Description of the Related Art In electrophotographic image forming apparatuses, toner bottles that supply, for instance, toner have to be strong enough so as not to break even when dropped; accordingly, molded articles resulting from injection stretch blow molding of polyethylene terephthalate (hereafter also referred to as "PET"), which is a polyester resin, are often used in such toner bottles. Japanese Patent Laid-Open No. 2001-042626 discloses a toner bottle obtained through stretch blow molding. Recycling of beverage PET bottles as new PET bottles has become widespread in recent years, for the sake of environment protection. Chemical recycling and material recycling are known PET recycling methods, as described in Japanese Patent Laid-Open No. 2014-198422 (paragraphs [0008] and [0009]). US 2009/258982 A1 relates to a biodegradable resin composition comprising 100 parts by mass of a biodegradable polyester resin such as polylactic acid and 0.1-15 parts by mass of a jojoba oil and/or a polar wax. EP 2 799 488 A1 relates to a 4-methyl-1-pentene/olefin (co) polymer composition comprising a specific 4-methyl-1-pentene (co)polymer (A) and a specific 4-methyl-1-pentene/α-olefin copolymer (B) in a specific ratio. US 2009/258175 A1 relates to a foam sheet made of a biodegradable resin composition containing a wax and/or a polyolefin resin, wherein the biodegradable resin is mainly composed of polylactic acid. WO2007/040243 A1 relates to a biodegradable resin composition comprising a biodegradable polyester resin, a layered silicate, and at least one component selected from a polyether phosphate ester compound, a polar wax and jojoba oil. JP 2009-155378 A relates to a biodegradable polyester resin composition obtained by melt-kneading 100 pts.mass of biodegradable polyester resin A containing 50 mol.% or more of α- and/or β-hydroxy carboxylic acid unit, 0.01-20 pts.mass of (meth)acrylate compound B having two or more of (meth)acryl group in a molecule, or one or more of (meth)acryl group and one or more of glycidyl group or a vinyl group, and 0.01-20 pts.mass of peroxide C, and contains further 0.1-20 pts.mass of a crystallization retarder D in the resin composition. JP 4 771204 B2 relates to a polyester resin composition obtained by melt-mixing two or more polyester resins comprising a thermoplastic polyester elastomer resin as an essential component of the component and having 10/90 to 99/1 mass ratio of Ge/Sb contained in the whole composition as the catalyst. SUMMARY OF THE INVENTION Chemical recycling requires a multi-step process as disclosed in Japanese Patent Laid-Open No. 2000-169623, and requires decomposition facilities and polymerization facilities, resulting in high recycling costs. In addition, the environmental burden arising from the chemical recycling is large. On the other hand, in material recycling, a process of washing bottles is generally performed. However, bottles may be washed a plurality of times using water, acids, alkalis and the like, and a drying process is also required. Therefore, washing bottles can also increase the environmental burden. Therefore, in order to reduce the environmental burden, the inventors simplified or omitted a process of washing of toner bottles to be recycled, and reproduced toner bottles using PET (hereinafter abbreviated as "MR-PET" for material recycled PET) obtained from toner bottles having toner still attached to the inside thereof. Thus, the inventors found that, when toners were stored in the toner bottles obtained in this manner, the surface of toner particles are sometimes deformed. The deformed toner particles may cause development defects, and development defects may cause density unevenness in electrophotographic images. At least one aspect of the present disclosure is to provide a method for producing a blow-molded article through which it is possible to prevent wax-derived components from being transferred to a surface of a blow-molded article. At least one aspect of the present disclosure is to provide a resin composition that contributes to preventing wax-derived components from being transferred to a surface of a blow-molded article. At least one aspect of the present disclosure is to provide pellets that contribute to preventing wax-derived components from being transferred to a surface of a blow-molded article. The present invention provides a method for producing a blow-molded article as specified in claims 1 to 10. According to at least one aspect of the present disclosure, it is possible to obtain a method for producing a blow-molded article through which it is possible to prevent wax-derived components from being transferred to a surface of a blow-molded article. In addition, according to at least one aspect of the present disclosure, it is possible to obtain a resin composition that contributes to prevent