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JP-7855908-B2 - Adhesive composition, adhesive, adhesive layer, adhesive sheet, laminate and adhesive composition

JP7855908B2JP 7855908 B2JP7855908 B2JP 7855908B2JP-7855908-B2

Inventors

  • 鈴木 秀昭
  • 中根 宇之

Assignees

  • 三菱ケミカル株式会社

Dates

Publication Date
20260511
Application Date
20220420
Priority Date
20210421

Claims (14)

  1. An adhesive composition containing a polyester resin (A) having structural sites derived from polycarboxylic acids (a1) and structural sites derived from polyhydric alcohols (a2), In the structural site derived from the above polycarboxylic acid (a1), the content of the structural site derived from aromatic polycarboxylic acid (a1-1) is 20 mol% or more. In the structural site derived from the above polyhydric alcohols (a2), the content of the structural site derived from polydienediol and/or hydrogenated polydienediol (a2-1) is 20 mol% or more. An adhesive composition characterized in that the total amount of structural sites derived from the above aromatic polycarboxylic acids (a1-1) and structural sites derived from polydienediol and/or hydrogenated polydienediol (a2-1) in the polyester resin (A) is 90% by weight or more.
  2. An adhesive composition containing a polyester resin (A) having structural sites derived from polycarboxylic acids (a1) and structural sites derived from polyhydric alcohols (a2), In the structural site derived from the above polycarboxylic acid (a1), the content of the structural site derived from aromatic polycarboxylic acid (a1-1) is 20 mol% or more. An adhesive composition characterized in that, in the structural site derived from the above polyhydric alcohol (a2), the content of the structural site derived from polydienediol and/or hydrogenated polydienediol (a2-1) is 70 mol% or more.
  3. The adhesive composition according to claim 2, characterized in that the total amount of structural sites derived from the above aromatic polycarboxylic acids (a1-1) and structural sites derived from polydienediol and/or hydrogenated polydienediol ( a2-1 ) in the polyester resin (A) is 90% by weight or more.
  4. The adhesive composition according to claim 1 or 2, characterized in that the total amount of structural sites derived from the above aromatic polycarboxylic acids (a1-1) and structural sites derived from polydienediol and/ or hydrogenated polydienediol (a2-1) in the polyester resin (A) is 95% by weight or more.
  5. The adhesive composition according to claim 1 or 2 , characterized in that the number average molecular weight of the polydienediol and/or hydrogenated polydienediol (a2-1) is 500 to 10000.
  6. The adhesive composition according to claim 1 or 2, characterized in that the polydienediol and/or hydrogenated polydienediol (a2-1) is a polydienediol formed from a conjugated diene having 4 to 9 carbon atoms and/or a hydrogenated polydienediol formed from a conjugated diene having 4 to 9 carbon atoms.
  7. The adhesive composition according to claim 1 or 2 , characterized in that the dielectric loss tangent of the polyester resin (A) at a frequency of 10 GHz under a temperature of 23°C and a relative humidity of 50% RH is 0.01 or less.
  8. The adhesive composition according to claim 1 or 2 , characterized in that the acid value of the polyester resin (A) is 10 mg KOH/g or less.
  9. The adhesive composition according to claim 1 or 2, further characterized by containing a crosslinking agent (B).
  10. An adhesive characterized by being a crosslinked adhesive composition according to claim 1 or 2 .
  11. An adhesive sheet comprising an adhesive layer in which an adhesive composition containing a polyester resin (A) having structural sites derived from polycarboxylic acids (a1) and structural sites derived from polyhydric alcohols (a2) and a crosslinking agent (B) is crosslinked, and an adhesive sheet having a release sheet on one side of the adhesive layer and a substrate on the other side, In the structural site derived from the above polycarboxylic acid (a1), the content of the structural site derived from aromatic polycarboxylic acid (a1-1) is 20 mol% or more. In the structural site derived from the above polyhydric alcohols (a2), the content of the structural site derived from polydienediol and/or hydrogenated polydienediol (a2-1) is 20 mol% or more. The dielectric loss tangent of the above adhesive layer at a frequency of 10 GHz under conditions of 23°C and 50% relative humidity is 0.01 or less. An adhesive sheet characterized in that the dielectric loss tangent at a frequency of 10 GHz under the above substrate conditions of a temperature of 23°C and a relative humidity of 50% RH is 0.01 or less.
  12. A laminate comprising a crosslinked adhesive layer containing a polyester resin (A) having structural sites derived from polycarboxylic acids (a1) and structural sites derived from polyhydric alcohols (a2), and a crosslinking agent (B), and a substrate on at least one surface of the adhesive layer, In the structural site derived from the above polycarboxylic acid (a1), the content of the structural site derived from aromatic polycarboxylic acid (a1-1) is 20 mol% or more. In the structural site derived from the above polyhydric alcohols (a2), the content of the structural site derived from polydienediol and/or hydrogenated polydienediol (a2-1) is 20 mol% or more. The dielectric loss tangent of the above adhesive layer at a frequency of 10 GHz under conditions of 23°C and 50% relative humidity is 0.01 or less. A laminate characterized in that the dielectric loss tangent at a frequency of 10 GHz under conditions of a temperature of 23°C and a relative humidity of 50% RH of the above-mentioned substrate is 0.01 or less.
  13. An adhesive composition containing a polyester resin (A) having structural sites derived from polycarboxylic acids (a1) and structural sites derived from polyhydric alcohols (a2), In the structural site derived from the above polycarboxylic acid (a1), the content of the structural site derived from aromatic polycarboxylic acid (a1-1) is 20 mol% or more. In the structural site derived from the above polyhydric alcohols (a2), the content of the structural site derived from polydienediol and/or hydrogenated polydienediol (a2-1) is 20 mol% or more. An adhesive composition characterized in that the total amount of structural sites derived from the above aromatic polycarboxylic acids (a1-1) and structural sites derived from polydienediol and/or hydrogenated polydienediol (a2-1) in the polyester resin (A) is 90% by weight or more.
  14. The adhesive composition according to claim 13, characterized in that the total amount of structural sites derived from the above aromatic polycarboxylic acids (a1-1) and structural sites derived from polydienediol and/or hydrogenated polydienediol ( a2-1 ) in the polyester resin (A) is 95% by weight or more.

Description

This invention relates to an adhesive composition, an adhesive obtained by crosslinking the adhesive composition, an adhesive layer, an adhesive sheet comprising the adhesive layer, a laminate, and an adhesive composition. More specifically, it relates to an adhesive composition having a low dielectric constant and low dielectric loss tangent, and excellent adhesive properties, and to an adhesive obtained by crosslinking this adhesive composition, an adhesive layer, an adhesive sheet comprising the adhesive layer, a laminate, and an adhesive composition. Traditionally, polyester resins have been used in a wide range of applications, including films, PET bottles, textiles, toners, electrical components, adhesives, and sealants, due to their excellent heat resistance, chemical resistance, durability, and mechanical strength. Furthermore, due to their high polarity inherent in their polymer structure, polyester resins are known to exhibit excellent adhesion to polar polymers such as polyester, polyvinyl chloride, polyimide, and epoxy resins, as well as to metallic materials such as copper and aluminum. For example, Patent Document 1 proposes a thermosetting composition containing a resin (e.g., a polyester resin), an organometallic compound, and a trifunctional or more epoxy group-containing compound, with a total amount of reactive functional groups that can react with at least one of an organometallic compound or an epoxy group-containing compound, and functional groups having heteroatoms other than halogens, ranging from 0.01 mmol/g to 9 mmol/g, for the purpose of obtaining a thermosetting adhesive sheet with excellent dimensional stability during curing and excellent adhesion, heat resistance, flexibility, electrical insulation, low dielectric constant, and low dielectric loss tangent after curing. Japanese Patent Publication No. 2017-031301 The configuration of the present invention will be described in detail below, but these are merely examples of preferred embodiments. In this invention, the term "class" appended to a compound name encompasses not only the compound itself but also its derivatives. For example, the term "carboxylic acids" includes not only carboxylic acids but also carboxylic acid derivatives such as carboxylic acid salts, carboxylic acid anhydrides, carboxylic acid halides, and carboxylic acid esters having approximately 1 to 8 carbon atoms. Furthermore, in this invention, "y and/or z (where y and z are any configuration or component)" means one of three combinations: y only, z only, or y and z. In this specification, an adhesive sheet refers to one in which a release film is laminated on at least one side of an adhesive, and a release film or a base film is laminated on the other side, and which is applied to an object by peeling off the release film. Such a release film may be a base film whose back surface has been treated for release. Furthermore, in this specification, an adhesive sheet refers to one in which an adhesive composition is coated onto a base film and the adhesive composition is directly attached to the adherend without laminating a release film. The adhesive composition of the present invention (hereinafter referred to as "the Composition") contains a polyester resin (A) comprising structural sites derived from polycarboxylic acids (a1) and structural sites derived from polyhydric alcohols (a2). First, let's explain polyester resin (A). <Polyester resin (A)> The polyester resin (A) contains structural sites derived from polycarboxylic acids (a1) and polyhydric alcohols (a2) in its molecule, wherein the content of structural sites derived from aromatic polycarboxylic acids (a1-1) in the polycarboxylic acid-derived structural sites is 20 mol% or more, and the content of structural sites derived from polydienediols and/or hydrogenated polydienediols (a2-1) [hereinafter sometimes referred to as "polydienediols (a2-1)"] in the polyhydric alcohol-derived structural sites is 20 mol% or more. Furthermore, it is preferable that the polyester resin (A) is obtained by esterifying polycarboxylic acids (a1) and polyhydric alcohols (a2). Polyester resins containing polybutadiene-derived structural components are generally known to be usable as adhesives, and the inclusion of polybutadiene structures improves their adhesion to polyolefins such as polypropylene. On the other hand, in the present invention, it has been found that by using a polyester resin (A) containing a specific amount or more of structural sites derived from aromatic polycarboxylic acids (a1-1) and a specific amount or more of structural sites derived from polydienediols (a2-1), the dielectric properties are uniquely improved (dielectric constant and dielectric loss tangent are reduced). Normally, making a resin hydrophobic improves its dielectric properties. However, in this invention, we have found that, surprisingly, by introducing a specific amount or more of structural sites derived from aromatic polycarboxyl