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JP-2026074628-A - Method for dismantling multilayer films, adhesive tapes, and laminates.

JP2026074628AJP 2026074628 AJP2026074628 AJP 2026074628AJP-2026074628-A

Abstract

[Problem] To provide a multilayer film that can be easily disassembled by leaving it in a high-temperature, high-humidity environment. Also, to provide an adhesive tape having the multilayer film. Furthermore, to provide a method for disassembling a laminate to which the adhesive tape is attached. [Solution] A multilayer film having an intermediate layer and an outermost layer on both sides of the intermediate layer, wherein the outermost layer contains a resin (A) with a biodegradability of less than 60%, the intermediate layer contains a resin (B) with a biodegradability of 60% or more, and the outermost layer (A) has a water vapor transmission rate (WVTR) of 15 g/( m² ·day) or more in an environment of 40°C and 90% RH. [Selection Diagram] None

Inventors

  • 吉田 妃那
  • 川原 良介
  • 森下原 卓

Assignees

  • 積水化学工業株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (14)

  1. An intermediate layer, and an outermost layer on both sides of the intermediate layer, The outermost layer contains resin (A) with a biodegradability of less than 60%, The aforementioned intermediate layer contains a resin (B) with a biodegradability of 60% or more. The outermost layer is a multilayer film characterized by having a water vapor transmission rate (WVTR) of 15 g/( m² ·day) or more under conditions of 40°C and 90% RH.
  2. The multilayer film according to claim 1, wherein the resin (A) comprises a resin with a melting point of 100°C or higher.
  3. The multilayer film according to claim 1 or 2, wherein the resin (A) comprises a polyester resin.
  4. The multilayer film according to claim 3, wherein the resin (A) comprises a resin having a polybutylene terephthalate skeleton.
  5. The multilayer film according to claim 1 or 2, wherein the outermost layer has a thickness of 50 μm or less.
  6. The multilayer film according to claim 1 or 2, wherein the resin (B) comprises a polyester resin.
  7. The multilayer film according to claim 6, wherein the resin (B) comprises at least one resin having a skeleton selected from the group consisting of polylactic acid, polybutylene succinate, polyglycolic acid, polycaprolactone, poly-3-hydroxybutyrate-co-hydroxyhexanoate, and polybutylene adipate terephthalate.
  8. The multilayer film according to claim 1 or 2, wherein the content ratio of resin (B) to the total resin contained in the intermediate layer is 50% by mass or more.
  9. The multilayer film according to claim 1 or 2, wherein the intermediate layer has a thickness of 30 μm or more and 200 μm or less.
  10. The multilayer film according to claim 1 or 2, wherein the total thickness of the multilayer film is 300 μm or less.
  11. A multilayer film according to claim 1 or 2, An adhesive tape having an adhesive layer on at least one surface of the multilayer film.
  12. The adhesive tape according to claim 11, wherein the adhesive layer contains at least one selected from the group consisting of urethane resin and (meth)acrylic copolymer.
  13. The adhesive tape according to claim 11, wherein the adhesive layer has a thickness of 75 μm or less.
  14. A laminate formed by attaching the adhesive tape described in claim 11 to a member, This process includes leaving the area standing for 6 hours or more in an environment with a temperature of 85°C or higher and a humidity of 85% or higher. Method for dismantling a laminated structure.

Description

This invention relates to multilayer films. Furthermore, it relates to adhesive tapes. Moreover, it relates to a method for dismantling laminates. Polyester film is used as a base material for adhesive tape, a release film to protect the adhesive layer of adhesive tape, and a release film to protect objects during the manufacturing process, among other applications. For example, Patent Document 1 discloses a release film in which a release layer is formed on at least one side of a polyester film. This release film, when used in the manufacture of electrical and electronic components, does not cause silicone transfer to the electrical and electronic component material, possesses release properties comparable to those of a silicone release layer, exhibits excellent processability, and has good release characteristics. Japanese Patent Publication No. 2003-148781 The embodiments of the present invention will be further described in detail below with reference to examples, but the present invention is not limited to these examples. (Preparation of acrylic adhesive) (1) Synthesis of (meth)acrylic copolymer: 52 parts by mass of ethyl acetate was placed in a reactor equipped with a thermometer, stirrer, and condenser, and after purging with nitrogen, the reactor was heated and reflux was started. 30 minutes after the ethyl acetate boiled, 0.08 parts by mass of azobisisobutyronitrile was added as a polymerization initiator. A monomer mixture consisting of 70 parts by mass of n-butyl acrylate, 27 parts by mass of 2-ethylhexyl acrylate, 3 parts by mass of acrylic acid, and 0.2 parts by mass of 2-hydroxyethyl acrylate was added dropwise and uniformly over 1 hour and 30 minutes to allow the reaction to proceed. 30 minutes after the end of the dropwise addition, 0.1 parts by mass of azobisisobutyronitrile was added, and the polymerization reaction was continued for a further 5 hours. By adding ethyl acetate to the reactor and cooling while diluting, a solution of (meth)acrylic copolymer with a solid content of 40% by mass was obtained. The weight-average molecular weight of the obtained (meth)acrylic copolymer was measured by GPC using a Waters "2690 Separations Module" column, and was found to be 710,000. (2) Preparation of the adhesive To 100 parts by mass of the solid content of the obtained (meth)acrylic copolymer, 15 parts by mass of polymerized rosin ester with a softening point of 150°C, 10 parts by mass of terpene phenol with a softening point of 145°C, and 10 parts by mass of rosin ester with a softening point of 70°C were added. Furthermore, 30 parts by mass of ethyl acetate and 1.8 parts by mass of a crosslinking agent (Desmodule L75, manufactured by Covestro) were added and stirred to obtain an adhesive solution. (Preparation of urethane-based adhesive) (1) In a four-necked flask equipped with a urethane resin synthesis stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, 112 g of polyoxypropylenediol polyol (hydroxyl value 56.1 mg KOH/g) produced by reacting propylene oxide with propylene oxide using propylene glycol as an initiator and a KOH catalyst, 14.5 g of 2,4-toluene diisocyanate (Mitsui Chemicals Fine, "Cosmonate T-100"), and dibutyltin dilaurate (DBTDL) as a urethane catalyst were added in an amount equivalent to 20 ppm relative to the total amount of polyoxypropylenediol polyol and 2,4-toluene diisocyanate. The temperature was then gradually raised to 80°C and the reaction was carried out for 2 hours to obtain a solution containing the prepolymer (NCO% was 1.80% by mass). The solution was then cooled to 60°C, and 85 g of ethyl acetate and 125 g of methyl ethyl ketone (MEK) were added to the solution containing the prepolymer. Subsequently, 1.52 g of N-(2-hydroxypropyl)ethanolamine and 1.14 g of 14-butanediol were added as chain extenders, and the reaction was carried out. The reaction was continued at 60°C, and when the NCO% fell to 0.10% by mass or less, 0.29 g of monoisopropanolamine (MIPA), a terminal termination agent, was added to terminate the reaction. The resulting polyurethane resin solution was colorless and transparent with a solid content of 42% by mass. Furthermore, the weight-average molecular weight (Mw) of the obtained polyurethane resin was measured by GPC using a Waters "2690 Separations Module" column, and it was found to be 80,000. (2) Preparation of adhesive The solids of the obtained urethane resin solution were mixed with 80 parts by mass, 20 parts by mass of terpene phenol resin (Yasuhara Chemical Co., Ltd., "YS Polystar T-145") as a tackifying resin, and 1.2 parts by mass of crosslinking agent (Covestro Co., Ltd., "Desmodule L75"), and stirred to obtain an adhesive solution. (Example 1) (1) Preparation of multilayer film 100 parts by mass of polybutylene terephthalate (PBT, Novaduran 5026 (manufactured by Mitsubishi Chemical Corporation)) was used as the outermost layer resin. 100 parts by mass of polybutylene succinate (PBS, BioPBS FZ91PB (manu