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JP-2026075932-A - Curable composition, cured product, and method for manufacturing a curable composition

JP2026075932AJP 2026075932 AJP2026075932 AJP 2026075932AJP-2026075932-A

Abstract

[Problem] To provide a curable composition that yields a cured product with excellent weather resistance, a cured product of the curable composition, and a method for producing the curable composition. [Solution] A curable composition comprising polymer A and polymer B, wherein polymer A is an oxyalkylene polymer having two or more terminal groups in one molecule, the terminal groups not having a divalent organic group represented by -C(=O)NH-, and the terminal groups having at least one group selected from the group consisting of a reactive silicon group, an unsaturated group, and a hydroxyl group, and having a silylation rate of 85 to 100 mol%, and polymer B is an alkyl (meth)acrylate polymer having a reactive silicon group. [Selection Diagram] None

Inventors

  • 金丸 明樹
  • 伊藤 高
  • ホ イング フ サムエル
  • 砂山 佳孝

Assignees

  • ＡＧＣ株式会社

Dates

Publication Date
20260511
Application Date
20241023

Claims (9)

  1. A curable composition comprising polymer A and polymer B, The polymer A is an oxyalkylene polymer having two or more terminal groups in one molecule, the terminal groups not having a divalent organic group represented by -C(=O)NH-, and the terminal groups having at least one group selected from the group consisting of a reactive silicon group, an unsaturated group, and a hydroxyl group represented by the following formula 1, and having a silylation rate of 85 to 100 mol% calculated by the following formula f1. The polymer B is a curable composition in which the polymer has a reactive silicon group represented by formula 1 below (meth)acrylate alkyl ester polymer. -SiR a X 3-a formula 1 [In Formula 1 above, R represents a monovalent organic group having 1 to 20 carbon atoms, excluding hydrolyzable groups, and X represents a hydroxyl group or a hydrolyzable group. a is an integer from 0 to 2. When a is 2, R may be the same or different from each other, and when a is 0 or 1, X may be the same or different from each other. The reactive silicon groups of polymer A and the reactive silicon groups of polymer B may be the same or different from each other.]
  2. The curable composition according to claim 1, wherein the number-average molecular weight of polymer A is 5,000 to 100,000.
  3. The curable composition according to claim 1, wherein the reactive silicon group of polymer A is a reactive silicon group represented by the following formula 3. -O-R 11 -SiR 12 a2 X 2 3-a2 Formula 3 [In Formula 3, R 11 is a linear alkylene group having 1 to 20 carbon atoms, and R 12 , X 2 , and a2 are the same as R, X, and a in Formula 1, respectively. When a2 is 2, R 12 may be the same or different from each other, and when a2 is 0 or 1, X 2 may be the same or different from each other.]
  4. The curable composition according to claim 1, wherein the number-average molecular weight of polymer B is 10,000 to 100,000.
  5. The curable composition according to claim 1, wherein the molecular weight distribution of polymer B is 4.0 or less.
  6. The curable composition according to claim 1, wherein polymer B has an average of 1.0 to 4.0 reactive silicon groups per molecule.
  7. A cured product of the curable composition according to any one of claims 1 to 6.
  8. A method for producing a curable composition according to any one of claims 1 to 6, Polymer A is obtained by reacting an unsaturated group-containing oxyalkylene polymer with a silylating agent in the presence of a group 8 metal catalyst and a co-catalyst containing either or both of a carboxylic acid compound having a carbon-carbon triple bond and a carboxylic acid compound having a carbon-carbon double bond at the α-carbon position. A method for producing a curable composition, comprising mixing polymer A and polymer B.
  9. The method for producing a curable composition according to claim 8, wherein the amount of silylation agent added is 0.85 to 1.50 molar times the total amount of unsaturated groups in the unsaturated group-containing oxyalkylene polymer.

Description

This invention relates to a curable composition, a cured product, and a method for producing a curable composition. Polymers containing at least one reactive silicon group per molecule are known to exhibit the property of crosslinking even at room temperature through the formation of siloxane bonds accompanied by hydrolysis reactions of the reactive silicon group due to moisture, etc., resulting in a rubbery cured product. Among these polymers containing reactive silicon groups, polymers with a main chain skeleton consisting of oxyalkylene polymers, saturated hydrocarbon polymers, alkyl acrylate polymers, and alkyl methacrylate polymers are already produced industrially and are widely used in applications such as sealants, adhesives, and paints. When curable compositions containing these polymers containing reactive silicon groups are used in the above applications, the tensile strength of the cured product is required. Cured products with excellent tensile strength are less prone to fracture. Patent Document 1 discloses a curable composition comprising an oxyalkylene polymer having two or more reactive silicon groups per molecule and a (meth)acrylic acid ester polymer having an average of 0.5 or more reactive silicon groups per molecule. It is stated that the cured product of the above curable composition exhibits excellent weather resistance and elongation properties. For example, Example 2 of Patent Document 1 describes a curable composition comprising a (meth)acrylic acid ester polymer with an average number average molecular weight of 15,500 and an average number average silicon group of 1.4 per molecule, and an oxyalkylene polymer with an average number average molecular weight of 23,000, a silylation rate of 60%, and an average number average silicon group of 2.4 per molecule. Japanese Patent Publication No. 2024-2114 The meanings and definitions of terms used in this specification are as follows: A numerical range represented by "~" means a range of numbers whose lower and upper limits are the numbers before and after "~". (Meth)acrylate alkyl ester polymer refers to a polymer containing repeating units based on (meth)acrylate alkyl ester monomers. (Meth)acrylate alkyl ester monomer refers to either or both of alkyl acrylate and alkyl methacrylate. The "units" that make up oxyalkylene polymers refer to atomic groups directly formed by the polymerization of alkylene oxide monomers. Oxyalkylene polymers are polymers consisting of a main chain containing polyoxyalkylene chains and terminal groups. In oxyalkylene polymers, the "main chain" refers to the portion (polyoxyalkylene chain) that includes residues obtained by removing active hydrogen from the initiator and repeating units based on alkylene oxide. In oxyalkylene polymers, the "end group" refers to the group of oxygen atoms in the polyoxyalkylene chain that is closest to the end of the molecule. However, if the group of oxygen atoms includes an initiator residue, it is not considered an end group but rather part of the main chain. An "active hydrogen-containing group" is at least one group selected from the group consisting of a hydroxyl group, carboxyl group, amino group, monovalent functional group obtained by removing one hydrogen atom from a primary amine, hydrazide group, and sulfanyl group, all of which are bonded to a carbon atom. "Active hydrogen" refers to hydrogen atoms based on the active hydrogen-containing group described above, and hydrogen atoms based on the hydroxyl group of water. An "unsaturated group" refers to a carbon-carbon double bond or a carbon-carbon triple bond. Carbon-carbon double bonds and carbon-carbon triple bonds may be located at the ends of the molecule or elsewhere. The number of terminal groups in an oxyalkylene polymer is the same as the number of active hydrogen atoms in the initiator, as will be discussed later. The "degree of unsaturation" can be measured according to the unsaturation measurement method (Wijs method). The degree of unsaturation indicates the proportion of carbon-carbon double bonds or carbon-carbon triple bonds in the polymer. The number-average molecular weight (Mn) and weight-average molecular weight (Mw) are polystyrene-equivalent molecular weights measured using GPC with tetrahydrofuran as the eluent, with a calibration curve created using polystyrene polymers of known molecular weight. The molecular weight distribution (Mw/Mn) is the ratio of Mw to Mn. The silylation rate can be measured by NMR analysis. A "silylation agent" refers to a compound that has a functional group that reacts with an unsaturated group and a reactive silicon group. ≪Curable composition≫ The curable composition of this embodiment comprises polymer A and polymer B described below. Polymer A is an oxyalkylene polymer having two or more terminal groups in one molecule, the terminal groups not having a divalent organic group represented by -C(=O)NH-, but having at least one group selected from the group consisting