Curable composition and cured product

Abstract

To provide a curable composition that can be cured by two types of external stimuli, that is, can undergo dual curing.SOLUTION: A curable composition contains (A) an organic polymer having a (meth)acryloyl group, (B) a compound X represented by a specific formula, and (C) a radical polymerization initiator, where, relative to 100 pts.wt. of (A), a content of (B) is 0.01 pt.wt. to 100.00 pts.wt., and a content of (C) is 0.001 pt.wt. to 20.000 pts.wt.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable composition and a cured product. [Background technology]

[0002] In recent years, attention has been focused on techniques for curing curable compositions by irradiation with light.

[0003] Known base polymers for such curable compositions include (meth)acryloyl group-containing polyisobutylene, polyacrylate, polyurethane, and epoxy resins. These resins have excellent gas barrier properties, tackiness, adhesiveness, and ease of handling, and can be instantaneously cured by UV irradiation.

[0004] For example, Patent Document 1 discloses a curable composition containing a vinyl polymer having at least one specific (meth)acryloyl group per molecule and having a main chain produced by living radical polymerization.

[0005] Furthermore, Patent Document 2 discloses a curable resin composition containing a vinyl ether group-containing acrylic acid ester polymer in which only acryloyl groups are polymerized. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-188550 [Patent Document 2] Japanese Patent Application Publication No. 2023-148665 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the above-mentioned conventional techniques are not sufficient from the viewpoint of curing by two types of external stimuli, i.e., dual cure, and there is room for further improvement.

[0008] One embodiment of the present invention has been made in consideration of the above-mentioned problems, and its object is to provide a novel curable composition that can be cured by two types of external stimuli, i.e., that is capable of dual curing. [Means for solving the problem]

[0009] The present inventors have conducted extensive research to solve the above problems and have completed the present invention.

[0010] That is, one embodiment of the present invention includes the following configuration. [1] A (meth)acryloyl group-containing organic polymer as component (A), a compound X represented by the following formula (1) as component (B),

[0011] [ka]

[0012] (In the formula (1), R 1 ~R 3 each independently represents hydrogen or a monovalent organic group; and a radical polymerization initiator as component (C), wherein the content of component (B) is 0.010 to 100,000 parts by weight and the content of component (C) is 0.001 to 20,000 parts by weight relative to 100 parts by weight of component (A). [2] The curable composition according to [1], wherein the component (A) comprises at least one selected from the group consisting of (meth)acryloyl group-containing hydrocarbon polymers, (meth)acryloyl group-containing (meth)acrylic polymers, (meth)acryloyl group-containing polyether polymers, (meth)acryloyl group-containing silicone polymers, (meth)acryloyl group-containing polyurethane polymers, and (meth)acryloyl group-containing epoxy resins. [3] The curable composition according to [1] or [2], wherein the component (A) has the (meth)acryloyl group at least at one or more ends of the organic polymer. [4] The curable composition according to any one of [1] to [3], wherein the (meth)acryloyl group in the component (A) includes a group represented by the following formula (2):

[0013] [ka]

[0014] (In formula (2), R 4 represents a hydrogen atom or a methyl group, and R 5 represents a divalent saturated hydrocarbon group having 2 to 6 carbon atoms and containing no heteroatoms, and R 6 ~R 9 each independently represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent alkoxy group having 1 to 20 carbon atoms, and the wavy line represents a bonding site to an organic polymer. [5] The curable composition according to any one of [1] to [4], wherein the component (A) contains an average of 1.0 to 10.0 (meth)acryloyl groups per molecule. [6] The curable composition according to any one of [1] to [5], wherein the component (C) contains a photoradical polymerization initiator. [7] A cured product obtained by curing the curable composition according to any one of [1] to [6]. [Effects of the Invention]

[0015] According to one embodiment of the present invention, it is possible to provide a curable composition that can be cured by two types of external stimuli, ie, that is capable of dual curing. DETAILED DESCRIPTION OF THE INVENTION

[0016] One embodiment of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to the respective configurations described below, and various modifications are possible within the scope of the claims. Furthermore, embodiments or examples obtained by combining the technical means disclosed in different embodiments or examples are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. All academic literature and patent documents described in this specification are incorporated herein by reference. Furthermore, unless otherwise specified in this specification, the term "A to B" representing a numerical range means "greater than or equal to A (including and greater than A) and less than or equal to B (including and less than B)."

[0017] 1. Technical Concept of the Present Invention Conventionally, as curable compositions that can be cured by irradiation with light (active energy rays), curable compositions containing, as main components, hydrocarbon polymers containing (meth)acryloyl groups, polyacrylates, polyurethanes, epoxy resins, etc. have been known.

[0018] When such curable compositions are actually used, there are cases where the cumulative light intensity of light irradiation is low or there are areas where light (e.g., UV light) does not reach, and in such cases, there is a problem that the curing of the curable composition does not proceed completely. That is, conventional curable compositions have a problem that curing is sometimes insufficient with light irradiation (e.g., UV irradiation) alone, resulting in unintended remaining uncured areas (also known as incomplete curing). In particular, since areas where light (e.g., UV light) does not reach can also be areas that are shielded from light, a mechanism for curing using external stimuli other than light, such as heat, was needed.

[0019] In view of these circumstances, the present inventors have conducted extensive research with the aim of providing a curable composition that can be cured by two types of external stimuli (e.g., light (active energy rays) and heat), i.e., that is capable of dual curing.

[0020] As a result, the present inventors independently discovered a novel finding that, surprisingly, dual cure is possible with a curable composition containing a (meth)acryloyl group-containing organic polymer and a compound having a specific structure, and have completed the present invention.

[0021] [2. Curable composition] A curable composition according to one embodiment of the present invention comprises a (meth)acryloyl group-containing organic polymer as component (A), a compound X represented by the following formula (1) as component (B), and

[0022] [ka]

[0023] (In the formula (1), R 1 ~R 3 each independently represents hydrogen or a monovalent organic group; and a radical polymerization initiator (C) as component (A), wherein the content of the component (B) is 0.010 to 100,000 parts by weight and the content of the component (C) is 0.001 to 20,000 parts by weight relative to 100 parts by weight of the component (A).

[0024] In this specification, the "curable composition according to one embodiment of the present invention" may be referred to as the "curable composition of the present invention."

[0025] The present curable composition has the above-described structure, and therefore has the advantage that it can be cured by two types of external stimuli (e.g., light (active energy rays) and heat), i.e., dual cure is possible. Furthermore, the present curable composition contains a (meth)acryloyl group-containing organic polymer as component (A), and therefore has the advantage that it can provide a cured product that has good gas barrier properties, tackiness, adhesiveness, ease of handling, etc.

[0026] In this specification, the phrase "capable of being cured by two types of external stimuli" or "capable of dual curing" means the following: (1) First, the curable composition is cured by a first type (first stage) of external stimulus (for example, light) to obtain a cured product. (2) Thereafter, a second type (second stage) of external stimulus (for example, heat) is applied to the obtained cured product to obtain a cured product. (3) For the cured product obtained by the first type of external stimulus and the cured product obtained by the second type of external stimulus, at least three physical properties (e.g., modulus, tensile strength at break, tensile elongation at break, and hardness) are measured, and the results are compared. (4) A curable composition is considered to be "capable of being cured by two types of external stimuli" or "capable of dual cure" if it satisfies the following conditions for at least three physical properties: The physical property value of the cured product obtained by the second kind of external stimulus is greater than the value obtained by multiplying the physical property value of the cured product obtained by the first kind of external stimulus by 0.95.

[0027] In the curable composition according to one embodiment of the present invention, it is more preferable that the physical property values ​​of the cured product obtained by the second external stimulus are the same as the physical property values ​​of the cured product obtained by the first external stimulus, and it is even more preferable that the physical property values ​​are greater than the physical property values ​​of the cured product obtained by the first external stimulus.

[0028] <Component (A): (Meth)acryloyl Group-Containing Organic Polymer> The present curable composition contains a (meth)acryloyl group-containing organic polymer as component (A). The (meth)acryloyl group-containing organic polymer can be a curable resin. It can also be said that the present curable composition contains the (meth)acryloyl group-containing organic polymer, which is component (A), as the curable resin.

[0029] In this specification, the term "(meth)acryloyl group-containing organic polymer" refers to an organic polymer having an average of 1.0 or more (meth)acryloyl groups per molecule. Furthermore, in this specification, the term "(meth)acryloyl group-containing organic polymer," i.e., an organic polymer having an average of 1.0 or more (meth)acryloyl groups per molecule, refers to an aggregate of organic polymer molecules having different numbers of (meth)acryloyl groups per molecule, where the average number of (meth)acryloyl groups per molecule is 1.0 or more. The aggregate may be composed solely of organic polymer molecules (hereinafter sometimes referred to as "monofunctionalized polymer molecules") having one (meth)acryloyl group per molecule (e.g., at only one end of the main chain (organic polymer)). Furthermore, the aggregate may contain, in addition to organic polymer molecules having one (meth)acryloyl group per molecule, organic polymer molecules having no (meth)acryloyl group (hereinafter sometimes referred to as "non-functionalized polymer molecules") and organic polymer molecules having two or more (meth)acryloyl groups per molecule (e.g., at both ends of the main chain (organic polymer)). Alternatively, the aggregate may be composed only of organic polymer molecules having no (meth)acryloyl groups and organic polymer molecules having two or more (meth)acryloyl groups per molecule. Note that the "number of (meth)acryloyl groups contained per molecule of the (meth)acryloyl group-containing organic polymer" can also be referred to as the "number of (meth)acryloyl groups introduced (or functionalization rate) per molecule of the (meth)acryloyl group-containing organic polymer."

[0030] As used herein, the term "(meth)acryloyl group" refers to an acryloyl group and / or a methacryloyl group (either an acryloyl group or a methacryloyl group, or both). Additionally, as used herein, the remainder of component (A) excluding the (meth)acryloyl group, i.e., the organic polymer itself that does not contain the (meth)acryloyl group, may be referred to as the "main chain" of component (A).

[0031] The (meth)acryloyl group-containing organic polymer has an average of 1.0 or more (meth)acryloyl groups per molecule. This provides the following advantages: (i) easy handling of the curable composition, (ii) easy availability of raw materials, (iii) excellent rapid curing properties, and (iv) ease of obtaining the dual cure effect. From these viewpoints, the (meth)acryloyl group-containing organic polymer of component (A) preferably has an average of 1.0 to 10.0 (meth)acryloyl groups per molecule, more preferably 1.0 to 8.0, even more preferably 1.0 to 5.0, and particularly preferably 1.0 to 3.0. Among the above-mentioned advantages, when rapid curing (fast takt time), high hardness, high strength, and high dual cure effects are particularly desired, the (meth)acryloyl group-containing organic polymer preferably contains an average of 2.0 to 10.0 (meth)acryloyl groups per molecule. Furthermore, when flexibility, elongation, and conformability to laminated members of the cured product are desired, the (meth)acryloyl group-containing organic polymer preferably contains an average of 1.0 to 3.0 (meth)acryloyl groups per molecule.

[0032] An example of a method for calculating the number of (meth)acryloyl groups contained in one molecule of a (meth)acryloyl group-containing organic polymer is shown below: (i) (meth)acryloyl group-containing organic polymer 1 H NMR measurement is performed; (ii) from the results obtained, (ii-1) the relative number (A) of organic polymer molecules present in the (meth)acryloyl group-containing organic polymer is calculated from the peak area (peak integral value) of protons attributed to groups derived from the polymerization initiator, and (ii-2) the relative number (B) of (meth)acryloyl groups present in the (meth)acryloyl group-containing organic polymer is calculated from the peak area (peak integral value) of protons attributed to the (meth)acryloyl group; (iii) by calculating the ratio (B / A) of the relative number (B) of (meth)acryloyl groups to the relative number (A) of organic polymer molecules, the number (introduction number) of (meth)acryloyl groups contained in one molecule of the (meth)acryloyl group-containing organic polymer can be determined.

[0033] The peak area of ​​the protons attributed to the groups derived from the polymerization initiator is 1 When the number of (meth)acryloyl groups (introduced number) contained per molecule of the (meth)acryloyl group-containing organic polymer cannot be determined from H NMR measurement, it can be determined as follows. That is, the number average molecular weight of the (meth)acryloyl group-containing organic polymer is determined by SEC (size exclusion chromatography) measurement, and then divided by the molecular weight of the monomer (repeating unit) that forms the (meth)acryloyl group-containing organic polymer, thereby determining the number of repeating units contained per molecule of the (meth)acryloyl group-containing organic polymer. The number of repeating units thus determined is multiplied by the number of protons characteristic of the monomer (not overlapping with other peaks), and the result is: 1 By adopting this as a reference value in H NMR measurement, the number of (meth)acryloyl groups (introduced number) contained per molecule of the (meth)acryloyl group-containing organic polymer can be determined in the same manner as above.

[0034] The manner in which the (meth)acryloyl group of component (A) is bonded to the organic polymer is not particularly limited, but examples include an ester bond, an ether bond, an amide bond, a urethane bond, a thioether bond, a carbonate bond, a urea bond, a bond consisting of a divalent or higher hydrocarbon group not containing a hetero atom, etc. Among these, ester bonds, ether bonds, amide bonds, and urethane bonds are preferred from the standpoint of ease of synthesis.

[0035] The bonding position of the (meth)acryloyl group of component (A) is not particularly limited, and it may be at the terminal or side chain of the organic polymer. For reasons of (a) ease of synthesis, (b) favorable physical properties as an elastomer material of the resulting cured product, (c) ease of control of the number of functional groups per polymer molecule, and (d) ease of industrially obtaining the raw materials, it is preferable that the (meth)acryloyl group of component (A) be bonded to the terminal of the organic polymer.

[0036] In a particularly preferred embodiment, the number of (meth)acryloyl groups contained (present) at the terminals of component (A) is preferably 1.0 to 2.0 on average per molecule, more preferably 1.5 to 2.0, and even more preferably 1.7 to 2.0. This configuration has the advantages of enhancing the dual cure effect and improving the properties of the cured product as an elastomer material (for example, properties such as hardness, strength, elongation, compression set, and gas barrier properties).

[0037] When focusing on one (meth)acryloyl group-containing organic polymer molecule rather than on an aggregate of (meth)acryloyl group-containing organic polymer molecules, (i) a (meth)acryloyl group-containing organic polymer molecule having one (meth)acryloyl group at its terminal means that the organic polymer molecule has a (meth)acryloyl group at only one of its two terminals, and (ii) a (meth)acryloyl group-containing organic polymer molecule having two (meth)acryloyl groups at its terminal means that the organic polymer molecule has a (meth)acryloyl group at both of its two terminals.

[0038] Component (A) preferably has a (meth)acryloyl group at at least one end of the organic polymer, and more preferably has a (meth)acryloyl group at both ends. This configuration has the advantages of enhancing the dual cure effect and improving the properties of the cured product as an elastomer material (for example, hardness, strength, elongation, compression set, gas barrier properties, etc.).

[0039] The (meth)acryloyl group of component (A) is not particularly limited, but it preferably contains a group represented by formula (2) below, and more preferably is a group represented by formula (2) below (consisting only of groups represented by formula (2) below), in order to achieve excellent physical properties of the cured product, easy availability of raw materials, and ease of production. Component (A) may be a mixture (aggregate) of (meth)acryloyl group-containing organic polymer molecules that contain a group represented by formula (2) below as a (meth)acryloyl group, and (meth)acryloyl group-containing organic polymer molecules that do not contain a group represented by formula (2) below as a (meth)acryloyl group.

[0040] [ka]

[0041] (In formula (2), R 4 represents a hydrogen atom or a methyl group, and R 5 represents a divalent saturated hydrocarbon group having 2 to 6 carbon atoms and containing no heteroatoms, and R 6 ~R 9 are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent alkoxy group having 1 to 20 carbon atoms, and the wavy line represents a bonding site to an organic polymer.

[0042] R 4 When R is a hydrogen atom, formula (2) is an acryloyl group, and R 4 When is a methyl group, formula (2) becomes a methacryloyl group.

[0043] Depending on the combination with other components to be blended in the present curable composition, either an acryloyl group or a methacryloyl group can be selected as the (meth)acryloyl group of component (A).

[0044] For example, when priority is placed on good fast curing properties, easy availability of raw materials, and cost-effectiveness, the (meth)acryloyl group of component (A) should be R 4On the other hand, when the heat resistance and durability of the cured product are important, it is preferable to select an acryloyl group in which R is a hydrogen atom as the (meth)acryloyl group in component (A). 4 In some cases, it may be preferable to select a methacryloyl group in which R is a methyl group. If it is found during research that mixing the two is preferable, the two may be used in combination. In the present curable composition, component (A) is 4 an acryloyl group-containing organic polymer molecule having an acryloyl group in which R is a hydrogen atom; 4 In the present curable composition, component (A) may be a mixture (aggregate) of methacryloyl group-containing organic polymer molecules having a methacryloyl group in which R is a methyl group. 4 is a hydrogen atom, and R is an acryloyl group. 4 The organic polymer molecule may contain an acryloyl group and a methacryloyl group, the acryloyl group being a methyl group.

[0045] R in Equation (1) 5 is a divalent saturated hydrocarbon group having 2 to 6 carbon atoms and containing no heteroatoms. 5 Specific examples include -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, and -CH2CH2CH2CH2CH2CH2-, etc. Among these, -CH2CH2-, -CH2CH2CH2-, and -CH2CH2CH2CH2- are preferred from the viewpoints of availability of raw materials and reactivity.

[0046] R in Equation (1) 6 ~R 9are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or an alkoxy group. Specific examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a 2-ethylhexyl group, a nonyl group, and a decanyl group. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group. R in formula (1) 6 ~R 9 are each independently (i) preferably at least one selected from the group consisting of a hydrogen atom, a methyl group, and a methoxy group from the viewpoint of reactivity, and (ii) more preferably a hydrogen atom in consideration of the availability of raw materials.

[0047] The number of groups represented by formula (2) contained (present) at the terminals of component (A) is preferably 1.0 to 2.0 on average per molecule, more preferably 1.5 to 2.0, and even more preferably 1.7 to 2.0. This configuration has the advantages of enhancing the dual cure effect and improving the properties of the cured product as an elastomer material (for example, hardness, strength, elongation, compression set, gas barrier properties, etc.).

[0048] When focusing on one (meth)acryloyl group-containing organic polymer molecule rather than an aggregate of (meth)acryloyl group-containing organic polymer molecules, (i) a (meth)acryloyl group-containing organic polymer molecule having one group represented by formula (2) at its terminal means that the organic polymer molecule has a group represented by formula (2) at only one of its two terminals, and (ii) a (meth)acryloyl group-containing organic polymer molecule having two groups represented by formula (2) at its terminal means that the organic polymer molecule has a group represented by formula (2) at both of its two terminals.

[0049] Component (A) preferably contains a group represented by formula (2) at at least one terminal of the organic polymer, and more preferably contains a group represented by formula (2) at both terminals. This configuration has the advantages of (i) fast curing, (ii) high strength, high hardness, high elongation, and good compression set, and (iii) high reactivity in dual cure.

[0050] The organic polymer in component (A) is not particularly limited, and examples thereof include hydrocarbon polymers, (meth)acrylic polymers, vinyl polymers, polyether polymers, silicone polymers, polyurethane polymers, epoxy resins, phenolic resins, benzoxazine resins, melamine resins, urea resins, and unsaturated polyester resins.

[0051] Component (A) is (i) a (meth)acryloyl group-containing hydrocarbon polymer, a (meth)acryloyl group-containing (meth)acrylic polymer, a (meth)acryloyl group-containing vinyl polymer, a (meth)acryloyl group-containing polyether polymer, a (meth)acryloyl group-containing silicone polymer, a (meth)acryloyl group-containing polyurethane polymer, a (meth)acryloyl group-containing epoxy resin, a (meth)acryloyl group-containing phenolic resin, a (meth)acryloyl group-containing benzoxazine resin, a (meth)acryloyl group-containing melamine ... (i) the resin composition preferably contains one or more resins selected from the group consisting of (meth)acryloyl group-containing urea resins and (meth)acryloyl group-containing unsaturated polyester resins, and more preferably consists of one or more resins selected from the group consisting of (i) (meth)acryloyl group-containing hydrocarbon polymers, (meth)acryloyl group-containing (meth)acrylic polymers, (meth)acryloyl group-containing vinyl polymers, (meth)acryloyl group-containing polyether polymers, (meth)acryloyl group-containing silicone polymers, (meth)acryloyl group-containing polyurethane polymers, (iii) a polymer selected from the group consisting of a (meth)acryloyl group-containing hydrocarbon polymer, a (meth)acryloyl group-containing (meth)acrylic polymer, a (meth)acryloyl group-containing polyether polymer, a (meth)acryloyl group-containing silicone polymer, a (meth)acryloyl group-containing polyurethane polymer, and a (meth)acryloyl group-containing epoxy resin; (iv) more preferably comprises one or more selected from the group consisting of (meth)acryloyl group-containing hydrocarbon polymers, (meth)acryloyl group-containing (meth)acrylic polymers, (meth)acryloyl group-containing polyurethane polymers, and (meth)acryloyl group-containing epoxy resins, and more preferably comprises one or more selected from the group consisting of (meth)acryloyl group-containing polyisobutylene polymers,It is more preferable that the composition contains one or more polymers selected from the group consisting of (meth)acryloyl group-containing polybutene polymers and (meth)acryloyl group-containing acrylic polymers, and it is particularly preferable that the composition is composed of only one or more polymers selected from this group. This composition has the advantages of (i) easy availability of raw materials, (ii) good handleability, (iii) excellent curability, (iv) good physical properties of the cured product, (v) excellent gas barrier properties of the cured product, and (vi) a high dual cure effect.

[0052] In particular, when a low-viscosity curable composition is desired, component (A) preferably comprises one or more selected from the group consisting of (meth)acryloyl group-containing polybutene polymers, (meth)acryloyl group-containing polyisobutylene polymers, (meth)acryloyl group-containing acrylic polymers, (meth)acryloyl group-containing polyether polymers, (meth)acryloyl group-containing silicone polymers, and (meth)acryloyl group-containing epoxy resins, and more preferably consists of only one selected from this group. Furthermore, in particular, when high durability and excellent gas barrier properties of the cured product are desired, component (A) preferably comprises one or more selected from the group consisting of (meth)acryloyl group-containing polyisobutylene polymers, (meth)acryloyl group-containing polybutene polymers, (meth)acryloyl group-containing acrylic polymers, and (meth)acryloyl group-containing epoxy resins, and more preferably consists of only one selected from this group.

[0053] In 100% by weight of component (A), the total content of one or more selected from the group consisting of (meth)acryloyl group-containing hydrocarbon polymers, (meth)acryloyl group-containing (meth)acrylic polymers, (meth)acryloyl group-containing vinyl polymers, (meth)acryloyl group-containing polyether polymers, (meth)acryloyl group-containing silicone polymers, (meth)acryloyl group-containing polyurethane polymers, and (meth)acryloyl group-containing epoxy resins is preferably 50% by weight or more, more preferably 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, even more preferably 90% by weight or more, and particularly preferably 100% by weight. In other words, it is particularly preferred that component (A) is one or more selected from the group consisting of (meth)acryloyl group-containing hydrocarbon polymers, (meth)acryloyl group-containing (meth)acrylic polymers, (meth)acryloyl group-containing vinyl polymers, (meth)acryloyl group-containing polyether polymers, (meth)acryloyl group-containing silicone polymers, (meth)acryloyl group-containing polyurethane polymers, and (meth)acryloyl group-containing epoxy resins. This configuration offers the following advantages: (i) easy availability of raw materials, (ii) good handleability, (iii) excellent curability, (iv) good physical properties of the cured product, (v) excellent gas barrier properties of the cured product, and (vi) a high dual cure effect.

[0054] ((Meth)acryloyl group-containing polyisobutylene polymer) In this section, a case where the component (A) contains a (meth)acryloyl group-containing polyisobutylene polymer, which is one type of (meth)acryloyl group-containing hydrocarbon polymer, will be described.

[0055] The polyisobutylene polymer in the (meth)acryloyl group-containing polyisobutylene polymer may be (a) a homopolymer of isobutylene, (b) a block copolymer, alternating copolymer, random copolymer, or graft copolymer of isobutylene and a monomer other than isobutylene, or (c) a mixture of two or more of these.

[0056] When the polyisobutylene polymer is a copolymer containing structural units derived from a monomer other than isobutylene, the ratio of the structural units derived from isobutylene to the structural units derived from the monomer other than isobutylene is not particularly limited as long as it does not impair the effects of the present invention. When the polyisobutylene polymer is a copolymer, the content of structural units derived from isobutylene in 100% by weight of the polyisobutylene polymer is preferably 50% by weight or more, and more preferably 60% by weight or more, in order to achieve excellent gas barrier properties and flexibility. When the content of structural units derived from isobutylene in 100% by weight of the polyisobutylene polymer is 50% by weight or more, the polyisobutylene polymer has the advantages of (i) easily exhibiting good gas barrier properties and flexibility, and (ii) easily obtaining good vibration damping properties, adhesiveness, and mechanical properties.

[0057] The monomer other than isobutylene used in the production of polyisobutylene polymers is not particularly limited as long as it is a monomer capable of cationic polymerization with isobutylene. Examples of the monomer other than isobutylene include aliphatic olefins such as 1-butene, aromatic vinyls such as styrene, methylstyrene, and α-methylstyrene, dienes such as 1,3-butadiene and isoprene, vinyl ethers such as butyl vinyl ether, silanes such as vinyltrimethylsilane and allyltrimethylsilane, terpenes such as α-pinene, β-pinene, and limonene, vinylcarbazole, and acenaphthylene. These may be used alone or in combination of two or more. Among these, from the viewpoints of copolymerizability with isobutylene and the physical properties of the resulting copolymer, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, α-pinene, β-pinene, limonene, isoprene, 1-butene, and 1,3-butadiene are particularly preferred as monomers other than isobutylene.

[0058] The molecular weight of the (meth)acryloyl group-containing polyisobutylene polymer is not particularly limited. From the viewpoint of ease of handling of the curable composition and physical properties of the cured product, the molecular weight of the (meth)acryloyl group-containing polyisobutylene polymer is preferably 500 to 300,000 in number average molecular weight, more preferably 1,000 to 300,000, more preferably 2,000 to 200,000, and even more preferably 3,000 to 100,000. When the number average molecular weight of the (meth)acryloyl group-containing polyisobutylene polymer is 500 or more, advantages include (a) sufficient strength of the cured product is easily obtained, (b) the curable composition is likely to exhibit a suitable range of surface tackiness and is easy to handle, and (c) physical properties characteristic of polyisobutylene polymers (good gas barrier properties, flexibility, etc.) are easily exhibited. Furthermore, when the number average molecular weight of the (meth)acryloyl group-containing polyisobutylene polymer is 300,000 or less, there is an advantage that good fluidity and processability are easily obtained.

[0059] The molecular weight distribution (represented by the ratio (Mw / Mn) of the weight-average molecular weight Mw to the number-average molecular weight Mn) of the (meth)acryloyl group-containing polyisobutylene polymer is preferably 1.00 to 2.00, more preferably 1.10 to 1.80. When the molecular weight distribution of the (meth)acryloyl group-containing polyisobutylene polymer is within the above-mentioned range, it has the advantages of (a) being able to reduce the melt viscosity of the resin, which tends to improve the handleability during molding and processing, and (b) tending to provide good physical properties of the cured product.

[0060] In this specification, the number average molecular weight and weight average molecular weight of the (meth)acryloyl group-containing polyisobutylene polymer are values ​​calculated in terms of polystyrene using size exclusion chromatography (SEC, also referred to as gel permeation chromatography (GPC)).

[0061] The method for producing a (meth)acryloyl group-containing polyisobutylene polymer is not particularly limited, and known methods can be used. For example, the production methods described in WO 2013 / 047314, JP 2013-216782 A, and WO 2017 / 099043 A are suitable because they offer high availability of raw materials, high productivity, and industrial suitability. These production methods include, for example, (i) a step of producing a polyisobutylene polymer by living cationic polymerization of isobutylene using a bifunctional polymerization initiator (e.g., dicumyl chloride) and a Lewis acid catalyst (e.g., TiCl4) in the presence of an electron donor component such as a nitrogen-containing compound (e.g., 2-methylpyridine, 2,6-dimethylpyridine, triethylamine, etc.), and (ii) a step of functionalizing the terminals of the polyisobutylene polymer using a (meth)acrylate phenoxyalkyl compound or the like. This method allows the production of polyisobutylene polymers having (meth)acryloyl groups at their terminals. In this method, it is particularly preferable to use solvents such as methyl chloride, butyl chloride, hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, and toluene, in terms of availability, solubility of raw materials and polymers, and economy. Furthermore, it is preferable to carry out the reaction at a low temperature (e.g., −70° C.). In step (ii) of this method, the functionalization rate can be controlled by adjusting the amount of the phenoxyalkyl (meth)acrylate compound used.

[0062] Furthermore, by changing the polymerization initiator, the number of (meth)acrylic groups introduced per molecule can be adjusted. That is, by using a monofunctional polymerization initiator or a trifunctional or higher functional polymerization initiator, a (meth)acrylic group-containing organic polymer containing the desired number of (meth)acrylic groups per molecule can be obtained.

[0063] Another example of such a method includes (i) a step of producing a monomer having both a functional group capable of cationically polymerizing with isobutylene (cationically polymerizable functional group) and a (meth)acryloyl group, and (ii) a step of randomly copolymerizing isobutylene with the monomer obtained in (i) by cationic polymerization. This method makes it possible to produce a polyisobutylene polymer having a (meth)acryloyl group in its side chain.

[0064] ((Meth)acrylic polymer containing (meth)acryloyl group) In this section, the case where the component (A) contains a (meth)acryloyl group-containing (meth)acrylic polymer will be described.

[0065] The number-average molecular weight of the (meth)acryloyl group-containing (meth)acrylic polymer, as measured by gel permeation chromatography (GPC), is preferably 3,000 to 100,000, more preferably 10,000 to 90,000, and even more preferably 30,000 to 80,000. When the number-average molecular weight of the (meth)acryloyl group-containing (meth)acrylic polymer is 3,000 or more, sufficient flexibility and rubber elasticity can be obtained in the cured product. When the number-average molecular weight of the (meth)acryloyl group-containing (meth)acrylic polymer is 100,000 or less, the viscosity of the polymer can be reduced, which has the advantage of making it easier to handle. Herein, GPC measurement of the (meth)acryloyl group-containing (meth)acrylic polymer is performed using chloroform as the mobile phase and a polystyrene gel (e.g., styrene / divinylbenzene copolymer gel) column, and the number-average molecular weight and other values ​​can be determined in terms of polystyrene.

[0066] The (meth)acrylic monomer from which the structural units constituting the (meth)acrylic polymer in the (meth)acryloyl group-containing (meth)acrylic polymer are derived is not particularly limited. Examples of the (meth)acrylic monomer include (meth)acrylic acid and (meth)acrylic acid esters. Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate. , stearyl (meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl (meth)acrylate, γ-(methacryloyloxypropyl)trimethoxysilane, ethylene oxide adduct of (meth)acrylic acid, trifluoromethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate, etc. These may be used alone or in combination of two or more.

[0067] The (meth)acrylic polymer preferably has structural units derived from a (meth)acrylic ester having an alkoxy group having 1 to 3 carbon atoms. Examples of (meth)acrylic ester monomers having an alkoxy group having 1 to 3 carbon atoms include 2-methoxyethyl (meth)acrylate and 3-methoxybutyl (meth)acrylate. The (meth)acrylic polymer preferably has 1 to 35% by weight of structural units derived from a (meth)acrylic ester having an alkoxy group having 1 to 3 carbon atoms, relative to 100% by weight of all structural units.

[0068] The (meth)acrylic polymer is preferably a polymer (A1) of a (meth)acrylic acid ester having an alkyl group having 3 to 5 carbon atoms, a (meth)acrylic acid ester having an alkyl group having 1 to 2 carbon atoms, and a (meth)acrylic acid ester having an alkoxy group having 1 to 3 carbon atoms. The monomer from which the structural units constituting the (meth)acrylic polymer (A1) are derived is not particularly limited, but examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, and 3-methoxybutyl (meth)acrylate.

[0069] The (meth)acrylic polymer (A1) preferably contains structural units derived from an acrylate ester having an alkyl group of 3 to 5 carbon atoms, structural units derived from an acrylate ester having an alkyl group of 1 to 2 carbon atoms, and structural units derived from an acrylate ester having an alkoxy group of 1 to 3 carbon atoms in a total amount of 80% by weight or more, more preferably 90% by weight or more, and even more preferably 95% by weight or more, of all structural units constituting the (meth)acrylic polymer (A1), with the upper limit being preferably 100% by weight or less.

[0070] The weight ratio of the structural units derived from a (meth)acrylic acid ester having an alkyl group of 3 to 5 carbon atoms, the structural units derived from a (meth)acrylic acid ester having an alkyl group of 1 to 2 carbon atoms, and the structural units derived from a (meth)acrylic acid ester having an alkoxy group of 1 to 3 carbon atoms that constitute the (meth)acrylic polymer (A1) (weight of structural units derived from a (meth)acrylic acid ester having an alkyl group of 3 to 5 carbon atoms / weight of structural units derived from a (meth)acrylic acid ester having an alkyl group of 1 to 2 carbon atoms / weight of structural units derived from a (meth)acrylic acid ester having an alkoxy group of 1 to 3 carbon atoms) is preferably 80 to 15 / 19 to 50 / 1 to 35.

[0071] The molecular weight distribution of the (meth)acryloyl group-containing (meth)acrylic polymer is preferably 1.8 or less, more preferably 1.7 or less, even more preferably 1.6 or less, still more preferably 1.5 or less, particularly preferably 1.4 or less, and most preferably 1.3 or less. The theoretical lower limit of the molecular weight distribution of the (meth)acryloyl group-containing (meth)acrylic polymer is 1. The molecular weight distribution is the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by GPC. When the molecular weight distribution of the (meth)acryloyl group-containing (meth)acrylic polymer is 1.8 or less, it has the advantage of being easy to control the mechanical properties of the resulting cured product.

[0072] The Tg of the (meth)acryloyl group-containing (meth)acrylic polymer may be −130° C. to 0° C., or −80° C. to −20° C. According to one embodiment of the present invention, the effect of dual cure can be obtained even when a (meth)acryloyl group-containing (meth)acrylic polymer having a low Tg and a high molecular weight is used.

[0073] The polymerization method for the (meth)acrylic polymer is not particularly limited, and examples thereof include the polymerization methods described in JP 2005-232419 A, JP 2006-291073 A, and JP 2016-88944 A. Examples of a method for introducing a group represented by formula (1) into the terminal of a (meth)acrylic polymer include the method described in paragraphs

[0081] to

[0087] of JP 2016-88944 A.

[0074] (Meth)acryloyl group-containing polyurethane polymers can be obtained by (i) reacting a polyhydric polyol with a polyfunctional isocyanate and a compound having a (meth)acryloyl group and a hydroxyl group. The polyhydric polyol may have a variety of skeletons. For example, polyhydric polyols having an ethylene oxide skeleton, a propylene oxide skeleton, a polyester polyol skeleton, other polyether skeletons, an OH group-containing polybutadiene skeleton, an OH group-containing hydrogenated polybutadiene skeleton, or an OH group-containing polyisobutylene skeleton can be used. (Meth)acryloyl group-containing polyurethane polymers can also be obtained by (ii) reacting a polyhydric polyol with a compound having a (meth)acryloyl group and an isocyanate group.

[0075] (Meth)acryloyl group-containing epoxy resins can be obtained by reacting a polyhydric polyol with (meth)acrylic acid, (meth)acrylic acid anhydride, (meth)acrylic acid chloride, or the like. The main skeleton of the polyhydric polyol may be the above-mentioned polymer, or a low-molecular-weight compound such as ethylene glycol, propylene glycol, pentaerythritol, glycerin, tartaric acid, or a monosaccharide. Alternatively, a polymer obtained by introducing a (meth)acryloyl group into a polyhydric polyol obtained by pre-copolymerizing these with a polyfunctional isocyanate may be used. For example, a (meth)acryloyl group-containing epoxy resin can be obtained by condensing (meth)acrylic acid with a bisphenol A epoxy resin, a bisphenol F epoxy resin, or a phenol novolac resin.

[0076] The organic polymer in the (meth)acryloyl group-containing organic polymer may be, for example, a polymer (copolymer) obtained by polymerizing one or more of the following monomers: aromatic vinyl monomers such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid and salts thereof; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, vinylidene fluoride; silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid; fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid; maleimide monomers such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, and cyclohexylmaleimide; Nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; alkenes such as ethylene and propylene; conjugated dienes such as butadiene and isoprene; vinyl chloride; vinylidene chloride; allyl chloride; allyl alcohol; and the like.

[0077] <(B) component; compound X> Component (B) is a compound X represented by the following formula (1):

[0078] [ka]

[0079] (In the formula (1), R 1 ~R 3 each independently represents hydrogen or a monovalent organic group.

[0080] The inclusion of component (B) in the curable composition enables the curing composition to be cured by two types of external stimuli (e.g., light (active energy rays) and heat), i.e., dual curing. The mechanism by which the inclusion of component (B) enables the curable composition to be dual cured is not completely clear, but is presumed to be as follows: First, a first-stage external stimulus (e.g., light irradiation such as UV) generates radical species from the radical polymerization initiator (component (C) described below). After the generated radical species initiates polymerization of component (A), component (B) also participates in the polymerization. It is presumed that component (B) thereby stabilizes the radical terminals of the resulting polymer (cured product) and prevents the radical terminals from being deactivated. It is presumed that a second-stage external stimulus (e.g., heating) then reactivates the radical terminals of the polymer, causing further polymerization. However, one embodiment of the present invention is in no way limited to this presumption.

[0081] R 1 ~R 3 The monovalent organic group in is not particularly limited, but examples thereof include an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aryl group, a hydroxy group, an acetyl group, an amino group, and a mercapto group.

[0082] Examples of the monovalent alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a 2-ethylhexyl group, a nonyl group, and a decanyl group.

[0083] Examples of the monovalent alkenyl group include a vinyl group and a β-methylvinyl group (either E- or Z-form).

[0084] Examples of the monovalent alkynyl group include an ethynyl group and a trimethylsilylethynyl group.

[0085] Examples of the monovalent alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, and a decanyloxy group.

[0086] Examples of the monovalent aryl group include a phenyl group, a 2-biphenyl group, a 3-biphenyl group, a 4-biphenyl group, a 1-naphthyl group, and a 2-naphthyl group.

[0087] R 1 is preferably one or more selected from the group consisting of hydrogen, an alkyl group, an aryl group, and an alkoxy group, more preferably one or more selected from the group consisting of hydrogen, an alkyl group, and an alkoxy group, and even more preferably one or more selected from the group consisting of hydrogen, a methyl group, and a methoxy group. This configuration has the advantages of (i) easy availability of raw materials, (ii) high solubility of component (B) in other components, and (iii) high reactivity.

[0088] R 2 is preferably one or more selected from the group consisting of hydrogen, an alkyl group, an aryl group, and an alkoxy group, more preferably one or more selected from the group consisting of hydrogen, an alkyl group, and an aryl group, further preferably an alkyl group, and particularly preferably a methyl group. This configuration has the advantages of (i) easy availability of raw materials, and (ii) high reactivity.

[0089] R 3 is preferably one or more selected from the group consisting of hydrogen, an alkyl group, an aryl group, and an alkoxy group, more preferably one or more selected from the group consisting of hydrogen, an alkyl group, and an aryl group, and even more preferably hydrogen. This configuration has the advantages of (i) easy availability of raw materials, and (ii) high reactivity.

[0090] R1 is hydrogen and R 2 is a methyl group, and R 3 is preferably hydrogen, that is, compound X is preferably α-methylstyrene dimer. This configuration has the advantages of (i) easy availability of raw materials, (ii) high solubility of component (B) in other components, and (iii) high reactivity.

[0091] In addition, because of its high stabilization effect on radical species, R 1 is a methoxy group or a dimethylamino group, R 2 is a methyl group, and R 3 is preferably hydrogen.

[0092] As the component (B), one type of compound may be used alone, or two or more types of compounds with different chemical formulas may be used in combination.

[0093] The content of component (B) in the curable composition is 0.010 to 100,000 parts by weight per 100 parts by weight of component (A). Having a content of component (B) of 0.010 parts by weight or more per 100 parts by weight of component (A) enables the curable composition to be cured by two types of external stimuli, i.e., dual cure. Having a content of component (B) of 100,000 parts by weight or less per 100 parts by weight of component (A) offers the following advantages: (i) excellent cost-effectiveness, (ii) reduced outgassing, (iii) excellent rapid curing properties, and (iv) low odor. From these viewpoints, the content of the (B) component in the present curable composition is preferably 0.010 parts by weight to 50,000 parts by weight, more preferably 0.010 parts by weight to 30,000 parts by weight, more preferably 0.010 parts by weight to 20,000 parts by weight, more preferably 0.010 parts by weight to 10,000 parts by weight, preferably 0.020 parts by weight to 7,000 parts by weight, more preferably 0.040 parts by weight to 5,000 parts by weight, more preferably 0.060 parts by weight to 3,000 parts by weight, even more preferably 0.080 parts by weight to 1,000 parts by weight, and particularly preferably 0.100 parts by weight to 0.750 parts by weight, relative to 100 parts by weight of the (A) component.

[0094] <Component (C) (radical polymerization initiator)> In this specification, the radical polymerization initiator (C) is a compound that generates radical species as active species capable of initiating polymerization of monomers upon exposure to external stimuli such as light (active energy rays) or heat. Component (C) is not particularly limited, but examples include known photoradical polymerization initiators and thermal radical polymerization initiators. Examples of component (C) include compounds described in International Publication WO 2013 / 047314 and JP 2013-216782 A.

[0095] As the photoradical polymerization initiator, (a) a compound having a hydroxyl group and a phenyl ketone structure, (b) a compound having a benzophenone structure, and (c) a compound having an acylphosphine oxide structure can be preferably used. As the thermal radical polymerization initiator, (d) an azo-based initiator, (e) a peroxide, (f) a persulfate, and (g) a redox initiator can be preferably used.

[0096] (a) Examples of compounds having a hydroxyl group and a phenyl ketone structure include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanon-1-one, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

[0097] (b) Examples of compounds having a benzophenone structure include benzophenone, 3-methoxybenzophenone, 4-methylbenzophenone, 4,4'-bis(diethylamino)benzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, and 4-chloro-4'-benzylbenzophenone.

[0098] (c) Examples of compounds having an acylphosphine oxide structure include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

[0099] (d) Azo initiators include 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (VAZO 33), 2,2'-azobis(2-amidinopropane) dihydrochloride (VAZO 50), 2,2'-azobis(2,4-dimethylvaleronitrile) (VAZO 52), 2,2'-azobis(isobutyronitrile) (VAZO 64), 2,2'-azobis-2-methylbutyronitrile (VAZO 67), 1,1-azobis(1-cyclohexanecarbonitrile) (VAZO 88), 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(methylisobutyrate) (V-601).

[0100] (e) Examples of peroxides include benzoyl peroxide, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, dicumyl peroxide, dicetyl peroxydicarbonate, t-butylperoxyisopropyl monocarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, t-butylperoxypivalate, and t-butylperoxy-2-ethylhexanoate.

[0101] (f) Examples of persulfates include potassium persulfate, sodium persulfate, and ammonium persulfate.

[0102] (g) Redox initiators include combinations of the above-mentioned persulfates with reducing agents (sodium metabisulfite, sodium bisulfite, etc.); systems based on organic peroxides and tertiary amines, such as a system based on benzoyl peroxide and dimethylaniline; and systems based on organic hydroperoxides and transition metals, such as a system based on cumene hydroperoxide and cobalt naphthate.

[0103] Component (C) preferably contains a photoradical polymerization initiator that generates radical species upon irradiation with active energy rays. This configuration offers the advantage of providing a curable composition with excellent curability and storage stability. More specifically, component (C) preferably contains or is at least one selected from the group consisting of benzophenone, 4,4'-bis(diethylamino)benzophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

[0104] When the curable composition can be heated for curing, a thermal radical polymerization initiator that generates radical species upon heating can be used as component (C). Alternatively, a photoradical polymerization initiator and a thermal radical polymerization initiator may be used in combination as component (C). When light irradiation is difficult or heat curing is preferred, component (C) is preferably an azo-based initiator or a peroxide. More specifically, component (C) preferably contains one or more compounds selected from the group consisting of 2,2'-azobis(methyl isobutylate), t-butyl peroxypivalate, di(4-t-butylcyclohexyl) peroxydicarbonate, t-butylperoxyisopropyl monocarbonate, dicumyl peroxide, benzoyl peroxide, and mixtures thereof, or may be one or more compounds selected from this group.

[0105] Component (C) may be used singly or in combination of two or more. One or more components of component (C) may also be used in combination with other compounds. When component (C) is used in combination with other compounds, suitable examples of such other compounds include amines such as diethanolmethylamine, dimethylethanolamine, and triethanolamine. Component (C) may be used in combination with the above-mentioned amines and an iodonium salt such as phenyliodonium chloride. Component (C) may be used in combination with the above-mentioned amines and a dye such as methylene blue.

[0106] The curable composition may further contain a polymerization inhibitor. The use of component (C) and a polymerization inhibitor in the curable composition reduces unintended curing of the curable composition, making it easier to handle. Examples of polymerization inhibitors include hydroquinone, hydroquinone monomethyl ether, benzoquinone, and p-tert-butylcatechol.

[0107] The component (C) preferably contains 70% by weight or more of the photoradical polymerization initiator, more preferably 80% by weight or more, even more preferably 90% by weight or more, and particularly preferably 100% by weight, of the 100% by weight of the component (C). In other words, it is particularly preferable that the component (C) is composed solely of the photoradical polymerization initiator. This configuration has the advantage of providing the curable composition with better curability and storage stability.

[0108] The content of component (C) in the curable composition is 0.001 to 20,000 parts by weight per 100 parts by weight of component (A). When the content of component (C) is 0.001 part by weight or more per 100 parts by weight of component (A), the effect of component (C) is exerted and good curability is obtained. Furthermore, when the content of component (C) is 20,000 parts by weight or less per 100 parts by weight of component (A), there is an advantage in that problems such as unintended heat generation, side reactions, and foaming during curing can be avoided. From these viewpoints, the content of component (C) in the present curable composition is preferably 0.010 parts by weight to 15,000 parts by weight, more preferably 0.030 parts by weight to 10,000 parts by weight, still more preferably 0.050 parts by weight to 5,000 parts by weight, even more preferably 0.080 parts by weight to 3,000 parts by weight, and particularly preferably 0.100 parts by weight to 1,000 parts by weight, per 100 parts by weight of component (A).

[0109] <Other ingredients> The curable composition may contain components other than the above-described components (A), (B), and (C) (hereinafter sometimes referred to as "other components") as needed, provided that the effects of the present invention are not impaired. Examples of other components include monomers, additives (e.g., fillers, hollow microparticles, plasticizers, storage stabilizers, antioxidants, UV absorbers, flame retardants, antistatic agents, pigments, thixotropy-imparting agents (anti-sagging agents), compatibilizers, curability modifiers, radical inhibitors, metal deactivators, antiozonants, phosphorus-based peroxide decomposers, lubricants, antifoaming agents, foaming agents, anti-termite agents, anti-fungal agents, and light stabilizers), elastomers (e.g., styrene-based block copolymers) that adjust the rubber properties of the cured product, thiol compounds, tertiary amine compounds, adhesion promoters, and solvents.

[0110] Specific examples of the other components are described in JP 2006-291073 A, paragraphs

[0134] to

[0151] , JP 2007-308692 A, paragraphs

[0232] to

[0235] , WO 2005 / 116134 A, paragraphs

[0089] to

[0093] , JP 4-69659 A, JP 7-108928 A, JP 63-254149 A, JP 64-22904 A, JP 2001-72854 A, etc.

[0111] The monomers in the other components are described below. The monomers can be blended into the curable composition to adjust the viscosity of the curable composition and / or the physical properties of the resulting cured product. The monomers contained in the curable composition can copolymerize with the above-mentioned component (A) and be incorporated as structural units into the resulting cured product. Suitable examples of the monomer include dicyclopentanyl (meth)acrylate, butyl (meth)acrylate, isononyl (meth)acrylate, isostearyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

[0112] <Method for producing the present curable composition> A curable composition can be obtained by mixing the above-mentioned components (A), (B), and (C), and, if necessary, other components.

[0113] The method for mixing the multiple components is not particularly limited, and examples include methods of mixing the multiple components using a hand mixer, static mixer, planetary mixer, disper, roll, kneader, single-screw extruder, twin-screw extruder, Banbury mixer, Brabender mixer, high-shear mixer, etc. Mixing may be performed in a dark environment, if necessary.

[0114] The present curable composition may be a one-component type, a two-component type, or a multi-component type having three or more components.

[0115] <Method for applying or filling the curable composition of the present invention> The method for applying or filling the curable composition onto an adherend is not particularly limited, and any known method for applying or filling a sealant, pressure-sensitive adhesive, or adhesive can be used. Examples of such methods include dispensing using an automatic coater, spraying, inkjet printing, screen printing, gravure printing, dipping, spin coating, die coating, and filling using a caulking gun or spray gun.

[0116] If the viscosity of the curable composition at room temperature is high and difficult to handle, the curable composition may be heated to the desired viscosity. The temperature of the curable composition after heating is preferably 100°C or lower, more preferably 80°C or lower. Heating the curable composition at 100°C or lower has the advantage that component (C) is less likely to volatilize. This provides safety benefits and prevents changes in the compounding ratio of each component in the curable composition.

[0117] [3. Cured product] A cured product according to one embodiment of the present invention is obtained by curing the present curable composition described in the section [2. Curable Composition]. The cured product according to one embodiment of the present invention is also simply referred to as the present cured product.

[0118] The cured product can have good gas barrier properties, tackiness, adhesiveness, ease of handling, and the like.

[0119] <Physical properties of the cured product> The present cured product can be used in a variety of applications, and can be suitably used, for example, in applications where rubber-like properties and / or relatively hard properties are required.

[0120] When the present cured product is used in applications requiring rubber-like properties and / or relatively hard properties, the hardness (Type A) of the present cured product is preferably 1 to 90 degrees, and more preferably 5 to 85 degrees. When the present cured product has a hardness (Type A) of (a) 1 degree or more, it has the advantage of not being too soft and easily achieving good surface tackiness and easy handling, and (b) when it is 90 degrees or less, it has the advantage of being less likely to crack. The method for measuring the hardness (Type A) of a cured product will be described in detail in the Examples below.

[0121] The tensile strength (MPa) of a cured product when elongated by X% is sometimes referred to as the "modulus at X% elongation." The "modulus at X% elongation" of a cured product is sometimes referred to as "MX." For example, "M30" refers to the "modulus at 30% elongation," which is the tensile strength (MPa) of a cured product when elongated by 30%.

[0122] The M30 of the present cured product is preferably 0.01 MPa to 5.00 MPa, more preferably 0.05 MPa to 3.00 MPa, and even more preferably 0.10 MPa to 2.00 MPa. This configuration has the advantage of providing a cured product that is well-balanced in terms of curability, flexibility, hardness, strength, etc., and is easy to handle.

[0123] The M50 of the present cured product is preferably 0.01 MPa to 10.00 MPa, more preferably 0.10 MPa to 5.00 MPa, and even more preferably 0.10 MPa to 3.00 MPa. This configuration has the advantage of providing a cured product that is well-balanced in terms of curability, flexibility, hardness, strength, etc., and is easy to handle.

[0124] The "tensile strength at break" of a cured product is sometimes referred to as "Tb." Also, the "tensile elongation at break" of a cured product is sometimes referred to as "Eb."

[0125] The Tb of the present cured product is preferably 0.01 MPa to 50.00 MPa, more preferably 0.10 MPa to 40.00 MPa, and even more preferably 0.50 MPa to 30.00 MPa. When the Tb of the present cured product is (a) 0.01 MPa or higher, the cured product has the advantage of having good strength and being easy to handle, and (b) when it is 50.00 MPa or lower, the cured product has the advantage of retaining rubber-like properties. Furthermore, when the Tb of the present cured product is within the above range, it has the advantage of being easily applicable to a variety of applications, such as sealing agents, moisture-proofing agents, potting agents, and gasket materials.

[0126] The cured product preferably has an Eb of 10% to 1000%, more preferably 30% to 500%, and even more preferably 100% to 500%. This configuration has the advantage of providing a cured product that can follow the movement of the adherend without peeling or breaking.

[0127] The methods for measuring M30, M50, Tb and Eb of the cured product will be described in detail in the Examples below.

[0128] <Curing method> The method for curing the curable composition of the present invention can also be said to be a method for producing a cured product. A method for producing a cured product according to one embodiment of the present invention includes a step of curing the curable composition according to one embodiment of the present invention described above. The cured product of the present invention is obtained by curing the curable composition of the present invention by applying an external stimulus (light (active energy rays) or heat). The curable composition may be placed in a mold and then cured. In other words, the cured product may be a molded product.

[0129] When component (C) contains a photoradical polymerization initiator, the external stimulus is irradiation with light (active energy rays). In this specification, active energy rays encompass all light in a broad sense, including, for example, radiation such as α-rays and β-rays, electromagnetic waves such as γ-rays and X-rays, electron beams (EB), ultraviolet rays (wavelengths of 100 to 400 nm), and visible light (wavelengths of 400 to 800 nm). The active energy rays are preferably ultraviolet rays. Examples of light sources for active energy rays include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, sodium lamps, halogen lamps, xenon lamps, LEDs, fluorescent lamps, sunlight, electron beam irradiation devices, and lasers.

[0130] The amount of irradiation of the active energy rays is not particularly limited, but the illuminance is 1 mW / cm 2 ~1000mW / cm 2 The illuminance is preferably 10 mW / cm 2 ~500mW / cm 2 It is more preferable that the illuminance is 100 mW / cm 2 ~500mW / cm 2 This configuration has the advantage of maintaining fast curing properties while contributing to the reduction of greenhouse gas emissions through energy savings.

[0131] The irradiation time of the active energy rays is not particularly limited, but is preferably 0.01 seconds to 1 hour, more preferably 0.10 seconds to 30 minutes, and even more preferably 0.50 seconds to 10 minutes. This configuration has the advantage of improving the takt time.

[0132] The irradiation dose of the active energy rays is not particularly limited, but the cumulative light dose is 1 mJ / cm 2 ~100,000mJ / cm 2 It is preferable that the integrated light amount is 50 mJ / cm 2 ~50,000mJ / cm 2 It is more preferable that the cumulative light amount is 100 mJ / cm 2 ~10,000mJ / cm 2This configuration has the advantages of (i) excellent rapid curing properties and improved takt time, (ii) preventing the cured product from heating, thereby enabling the use of heat-sensitive raw materials, and (iii) suppressing the volatilization of low-boiling-point components, thereby reducing the environmental impact.

[0133] Efficient curing can be achieved by matching the wavelength of the active energy rays emitted from the light source as closely as possible to the absorption wavelength (and / or maximum absorption wavelength) of component (C).

[0134] When component (C) contains a thermal radical polymerization initiator, the external stimulus is heat (heating).

[0135] The heating temperature is not particularly limited and may be appropriately set depending on the type of thermal radical polymerization initiator used, etc. The heating temperature is usually preferably 50°C to 250°C, more preferably 70°C to 200°C.

[0136] The heating time (curing time) is not particularly limited and may be set appropriately depending on the type of thermal radical polymerization initiator used, additives, heating temperature (reaction temperature), etc. The heating time (curing time) is usually in the range of 1 minute to 5 hours.

[0137] Furthermore, the present curable composition is capable of being cured by two types of external stimuli, i.e., dual curing. Therefore, for example, after the present curable composition is cured by irradiation with light (active energy rays), the obtained cured product can be further cured by applying heat. When the cured product obtained by curing by irradiation with light (active energy rays) is further heated, the heating temperature and heating time are not particularly limited, and the heating temperature and heating time described above can be preferably applied.

[0138] The curable composition can be cured under various atmospheres, such as air, nitrogen, and argon. Curing the curable composition under air is preferred because it does not require special equipment and can be easily performed. Furthermore, when there is a concern that oxygen in the air may inhibit curing, curing is preferably performed under an inert gas, such as nitrogen or argon.

[0139] In one embodiment of the present invention, even if the curable composition contains a photoradical polymerization initiator as component (C) but does not contain a thermal radical polymerization initiator, the polymerization system can be reactivated by simply heating in the second stage after the first stage of curing by irradiation with light (active energy rays), making dual curing possible. As described above, the mechanism by which dual curing is possible is unclear, but is presumed to be as follows. That is, it is presumed that the terminals of the polymer (cured product) obtained by irradiation with light (active energy rays) are stabilized by component (B) and are not deactivated, so that subsequent heating reactivates the radical terminals, causing further polymerization. However, one embodiment of the present invention is in no way limited to this presumption.

[0140] [4.Applications] The present curable composition can be suitably used in a variety of applications. Examples of such applications include sealing materials, pressure-sensitive adhesives, sealants, gasket materials, adhesives, coating materials, covering materials, resist materials, vibration-proofing materials, vibration-damping materials, shock-absorbing materials, buffer materials, electrical insulating materials, foams, paints, inks, casting agents, potting agents, molding materials, underfill materials, die-bonding materials, and fillers in electrical and electronic components (LEDs, batteries, sensors, semiconductors, circuit boards, displays, home appliances, optical communications and optical circuits, optical recording, magnetic recording, etc.), pharmaceuticals and medical products, automotive and marine parts, building components, and acoustic components. The present curable composition can also be used in various forms, such as sheets (films), tapes, and molded articles (packing, O-rings, belts, tubes, valves, hoses, etc.).

[0141] The present curable composition is capable of being cured by two types of external stimuli, i.e., dual curing. For example, after the present curable composition is cured by irradiation with light (active energy rays), the resulting cured product can be further cured by applying heat. Therefore, even when the present curable composition is applied to a substrate (substrate) that receives varying amounts of light from one direction, after curing by light irradiation, the curable composition present in areas that are insufficiently irradiated with light can be further cured by heating. Therefore, the present curable composition can be suitably used in areas with complex structures that block UV light, and is particularly suitable for use in electrical and electronic applications. [Example]

[0142] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0143] Measurements and evaluations in the examples and comparative examples were carried out by the following methods.

[0144] [Measurement and evaluation methods] <Surface tack> The stickiness of the surface of a 0.5 mm thick sheet-like cured product was evaluated by touching with a finger. The evaluation was on a scale of 1 to 5, with 1 being the least sticky surface and 5 being the most sticky uncured product. In other words, the smaller the number, the less sticky the surface, i.e., the better the surface tackiness.

[0145] <Tensile properties> The tensile properties of the 0.5 mm thick sheet-like cured product were measured in accordance with JIS K 6251:2017. First, the sheet-like cured product was punched into a No. 7 dumbbell shape, and the resulting dumbbell-shaped cured product was used as a test specimen. Next, a tensile test was performed using the resulting test specimen at a temperature of 23°C and a tensile speed of 200 mm / min to measure the modulus, tensile strength at break, and tensile elongation at break. The results are shown in Table 1.

[0146] <Hardness (A type)> Three 2 mm thick sheets of the cured product were stacked together to form a sample. The hardness (Type A) of the sample was measured using a Type A durometer in accordance with JIS K 6253:2012.

[0147] Furthermore, the tensile properties and hardness of the cured product obtained by UV light irradiation (pre-heating cured product) were compared with those of the cured product obtained by heating after photocuring (post-heating cured product). If the post-heating cured product's property value was greater than the value obtained by multiplying the pre-heating cured product by 0.95, it was evaluated as "1" (good), and if it was less than this value, it was evaluated as "0" (poor). The results are shown in Table 1.

[0148] <Gel fraction> Approximately 1 g of the 0.5 mm thick sheet-like cured product was used as a sample, and the weight of the sample (cured product) was measured and designated W1 (g). The sample was then immersed in toluene (toluene of approximately 200 times the weight of the sample was used) and left to stand at 70°C for 24 hours. The sample and toluene were then cooled to room temperature, and the precipitate was collected by filtration. The precipitate was then dried at 80°C under reduced pressure for 24 hours. The weight of the dried precipitate was measured and designated W2 (g). The gel fraction was calculated using the following formula: Gel fraction (%) = (W2 / W1) × 100.

[0149] 〔material〕 The materials used in the following examples and comparative examples are as follows. <Component (A)> Polyisobutylene containing acryloyl groups at both ends (Kaneka Corporation, "EP400V") <(B) component> α-methylstyrene dimer (in formula (1), R 1 is hydrogen and R 2 is a methyl group, and R 3 is hydrogen) <Compounds other than component (B)> 4-Hydroxy-TEMPO free radical <(C) component> 2-Hydroxy-2-methyl-1-phenyl-propan-1-one (IGM Resins, "Omnirad1173") Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (IGM Resins, "Omnirad819") <Other ingredients> Dicyclopentanyl acrylate (Resonac Corporation, "FA-513AS") Examples and Comparative Examples (Production of Curable Composition) The components were weighed in the proportions shown in Table 1 and mixed uniformly to obtain a curable composition.

[0150] (Production of cured product) The obtained curable composition was applied to a polyethylene terephthalate sheet coated with a release agent to a thickness of 0.5 mm. Next, the curable composition was irradiated with UV light using a UV irradiation device (manufactured by Fusion UV Systems Japan, model: LH6) (irradiation conditions: illuminance 500 mW / cm 2 , light intensity 5,000mJ / cm 2 ), a 0.5 mm-thick sheet-like cured product was obtained. The obtained curable composition was then applied to a polyethylene terephthalate sheet coated with a release agent to a thickness of 2 mm. Next, UV light was irradiated using the same UV irradiation device and under the same conditions as when the 0.5 mm-thick sheet-like cured product was obtained, thereby obtaining a 2 mm-thick sheet-like cured product.

[0151] The resulting 0.5 mm thick and 2 mm thick cured sheets were used to evaluate various physical properties. The results are shown in the "Cured product before heating" column in Table 1.

[0152] Next, a 0.5 mm thick sheet of cured material and a 2 mm thick sheet of cured material were each heated at 130°C for 1 hour to obtain a cured product. The obtained cured products were evaluated for the same physical properties. The results are shown in the "Cured product after heating" column in Table 1.

[0153] [Table 1]

[0154] As can be seen from Table 1, the curable compositions of Comparative Examples 1 to 3, which used 4-hydroxy-TEMPO free radical, produced cured products after heating that were inferior in many physical properties to those of the cured products before heating. On the other hand, the curable compositions of Examples 1 to 3, which used α-methylstyrene dimer, produced cured products after heating that were equivalent to or superior to those of the cured products before heating in all evaluated physical properties. These results demonstrate that the curable composition according to one embodiment of the present invention can be cured by heating even in areas where curing by light irradiation is insufficient, and can be cured by two types of external stimuli, i.e., dual curing is possible. [Industrial Applicability]

[0155] The curable composition of the present invention can be used for applications such as sealing materials, pressure-sensitive adhesives, sealing materials, gasket materials, adhesives, coating materials, covering materials, resist materials, vibration-proofing materials, vibration-damping materials, shock-absorbing materials, buffer materials, electrical insulating materials, foams, paints, inks, casting agents, potting agents, molding materials, underfill materials, die-bonding materials, and fillers in, for example, electric and electronic components (LEDs, batteries, sensors, semiconductors, circuit boards, displays, home appliances, optical communications and optical circuits, optical recording, magnetic recording, etc.), pharmaceuticals and medical products, automobile and ship parts, building components, and acoustic components, and is particularly suitable for use in electric and electronic applications.

Claims

1. a (meth)acryloyl group-containing organic polymer as component (A); A compound X represented by the following formula (1) as component (B), 【Chemistry 1】 (In the formula (1), R １ ~R ３ each independently represents hydrogen or a monovalent organic group. and a radical polymerization initiator as component (C), For 100 parts by weight of the component (A), The content of the (B) component is 0.010 parts by weight to 100,000 parts by weight, The content of the component (C) is 0.001 to 20,000 parts by weight.

2. 2. The curable composition according to claim 1, wherein the component (A) comprises at least one selected from the group consisting of a (meth)acryloyl group-containing hydrocarbon polymer, a (meth)acryloyl group-containing (meth)acrylic polymer, a (meth)acryloyl group-containing polyether polymer, a (meth)acryloyl group-containing silicone polymer, a (meth)acryloyl group-containing polyurethane polymer, and a (meth)acryloyl group-containing epoxy resin.

3. The curable composition according to claim 1 , wherein the component (A) has the (meth)acryloyl group at at least one terminal of an organic polymer.

4. The curable composition according to claim 1 , wherein the (meth)acryloyl group in the component (A) includes a group represented by the following formula (2): 【Chemistry 2】 (In formula (2), R ４ represents a hydrogen atom or a methyl group, R ５ represents a divalent saturated hydrocarbon group having 2 to 6 carbon atoms and containing no heteroatoms, R ６ ~R ９ each independently represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent alkoxy group having 1 to 20 carbon atoms; The wavy lines represent the bond to the organic polymer.)

5. 2. The curable composition according to claim 1, wherein the component (A) contains an average of 1.0 to 10.0 (meth)acryloyl groups per molecule.

6. The curable composition according to claim 1 , wherein the component (C) comprises a photoradical polymerization initiator.

7. A cured product obtained by curing the curable composition according to any one of claims 1 to 6.

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