阅读说明：本技术 树脂组合物、蓄热材和物品 (Resin composition, heat storage material, and article ) 是由 古川直树 永井晃 森本刚 木泽桂子 松原望 于 2018-05-10 设计创作，主要内容包括：本发明的一个方面为一种树脂组合物,其含有丙烯酸树脂和固化剂,丙烯酸树脂是使包含第一单体和第二单体的单体成分聚合而成的树脂,所述第一单体由下述式(1)表示,所述第二单体能够与第一单体共聚,且具有能够与固化剂反应的反应性基团。[式中,R<Sup>1</Sup>表示氢原子或甲基,R<Sup>2</Sup>表示碳原子数12～30的烷基。][化1]<Image he="428" wi="700" file="DDA0002267743170000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(One aspect of the invention is a treeA resin composition comprising an acrylic resin and a curing agent, wherein the acrylic resin is a resin obtained by polymerizing monomer components including a first monomer represented by the following formula (1) and a second monomer which is copolymerizable with the first monomer and has a reactive group capable of reacting with the curing agent. [ in the formula, R 1 Represents a hydrogen atom or a methyl group, R 2 Represents an alkyl group having 12 to 30 carbon atoms.][ formula 1])

1. A resin composition comprising an acrylic resin and a curing agent,

the acrylic resin is a resin obtained by polymerizing a monomer component including a first monomer represented by the following formula (1) and a second monomer which is copolymerizable with the first monomer and has a reactive group capable of reacting with the curing agent,

[ solution 1]

In the formula, R¹Represents a hydrogen atom or a methyl group, R²Represents an alkyl group having 12 to 30 carbon atoms.

2. A resin composition comprising an acrylic resin and a curing agent,

the acrylic resin comprises a first structural unit represented by the following formula (2) and a second structural unit having a reactive group capable of reacting with the curing agent,

[ solution 2]

In the formula, R³Represents a hydrogen atom or a methyl group, R⁴Represents an alkyl group having 12 to 30 carbon atoms.

3. The resin composition according to claim 1 or 2, wherein the curing agent is at least one curing agent selected from the group consisting of an isocyanate-based curing agent, a phenol-based curing agent, an amine-based curing agent, an imidazole-based curing agent, and an acid anhydride-based curing agent.

4. The resin composition according to any one of claims 1 to 3, wherein the reactive group is at least one group selected from the group consisting of a carboxyl group, a hydroxyl group, an isocyanate group, an amino group and an epoxy group.

5. The resin composition according to claim 1, wherein a content of the first monomer is 60 parts by mass or more with respect to 100 parts by mass of the monomer component.

6. The resin composition according to claim 1 or 5, wherein a content of the second monomer is less than or equal to 25 parts by mass with respect to 100 parts by mass of the monomer component.

7. The resin composition according to claim 2, wherein the content of the first structural unit is 60 parts by mass or more with respect to 100 parts by mass of all structural units constituting the acrylic resin.

8. The resin composition according to claim 2 or 7, wherein a content of the second structural unit is less than or equal to 25 parts by mass with respect to 100 parts by mass of all structural units constituting the acrylic resin.

9. The resin composition according to any one of claims 1 to 8, wherein the acrylic resin is contained in an amount of 50 parts by mass or more per 100 parts by mass of the resin composition.

10. The resin composition according to any one of claims 1 to 9, wherein the reactive group is an epoxy group.

11. The resin composition according to any one of claims 1 to 10, which is liquid at 90 ℃.

12. The resin composition of claim 11, the acrylic resin having a weight average molecular weight of 100000 or less.

13. The resin composition of claim 11 or 12, having a viscosity at 90 ℃ of less than or equal to 100 Pa-s.

14. The resin composition according to any one of claims 1 to 10, wherein the weight average molecular weight of the acrylic resin is 200000 or more.

15. The resin composition according to any one of claims 1 to 14, which is used for forming a heat storage material.

16. The resin composition according to any one of claims 1 to 14, which is used for forming a water repellent material, an anti-frost material, a refractive index adjuster, a lubricant, an adsorbent, a thermosetting stress relaxation material, or a low dielectric material.

17. A heat-accumulative material comprising a cured product of the resin composition according to any one of claims 1 to 16.

18. An article, comprising: a heat source; and a cured product of the resin composition according to any one of claims 1 to 16, which is provided in thermal contact with the heat source.

Technical Field

The present invention relates to a resin composition, a heat-accumulative material and an article.

Background

The heat storage material is a material that can take out stored energy as heat as needed. The heat-accumulating material is used for electronic parts such as air conditioners, floor heating equipment, refrigerators, and IC chips, automobile parts such as automobile interior and exterior materials and carbon tanks (cans), heat-insulating containers, and the like.

As a method of storing heat, latent heat storage using a phase change of a substance is widely used in terms of the magnitude of heat. As the latent heat-storing substance, water-ice is well known. Water-ice is a thermally massive substance, but the phase transition temperature is limited to 0 ℃ in the atmosphere, and thus the applicable range is also limited. Therefore, paraffin is used as the latent heat storage substance having a phase transition temperature higher than 0 ℃ and less than or equal to 100 ℃. However, since paraffin becomes liquid when phase-changed by heating and there is a risk of ignition or firing, in order to use paraffin for a heat storage material, it is necessary to store paraffin in a closed container such as a bag or the like to prevent paraffin from leaking from the heat storage material, and there is a limitation in the field of application.

Therefore, as a method for improving a heat-accumulative material containing paraffin, for example, patent document 1 discloses a method using a gelling agent. The gel produced by this method can retain a gel-like molded body even after paraffin phase transition. However, in this method, when used as a heat storage material, there is a possibility that liquid leakage, volatilization of the heat storage material, or the like occurs.

As another improvement method, for example, patent document 2 discloses a method of using a hydrogenated conjugated diene copolymer. In this method, the shape can be maintained at a temperature near the melting or solidification temperature of the hydrocarbon compound, but if the temperature is raised to a higher temperature, the compatibility is low, and therefore phase separation occurs, resulting in liquid leakage of the hydrocarbon compound.

As another improvement method, for example, patent document 3 discloses a method of microencapsulating a heat-accumulative material. In this method, the heat storage material is encapsulated, and therefore, the handling property is good regardless of the phase change, but the heat storage material may leak out of the capsule in a high temperature region.

Disclosure of Invention

Problems to be solved by the invention

An object of one aspect of the present invention is to provide a resin composition that can be suitably used for a heat storage material. Another object of the present invention is to provide a heat storage material having an excellent heat storage amount.

Means for solving the problems

The present inventors have conducted intensive studies and as a result, have found that a resin composition containing a specific component can be suitably used for a heat storage material, that is, a heat storage material formed of the resin composition is excellent in heat storage amount, and have completed the present invention. The present invention provides the following [1] to [18] in several aspects.

[1] A resin composition comprising an acrylic resin and a curing agent, wherein the acrylic resin is a resin obtained by polymerizing monomer components comprising a first monomer represented by the following formula (1) and a second monomer which is copolymerizable with the first monomer and has a reactive group capable of reacting with the curing agent.

[ solution 1]

[ in the formula, R¹Represents a hydrogen atom or a methyl group, R²Represents an alkyl group having 12 to 30 carbon atoms]。

[2] A resin composition contains an acrylic resin and a curing agent, wherein the acrylic resin contains a first structural unit represented by the following formula (2) and a second structural unit having a reactive group capable of reacting with the curing agent.

[ solution 2]

[ in the formula, R³Represents a hydrogen atom or a methyl group, R⁴Represents an alkyl group having 12 to 30 carbon atoms]。

[3] The resin composition according to [1] or [2], wherein the curing agent is at least one curing agent selected from the group consisting of isocyanate-based curing agents, phenol-based curing agents, amine-based curing agents, imidazole-based curing agents and acid anhydride-based curing agents.

[4] The resin composition according to any one of [1] to [3], wherein the reactive group is at least one group selected from the group consisting of a carboxyl group, a hydroxyl group, an isocyanate group, an amino group and an epoxy group.

[5] The resin composition according to [1], wherein the content of the first monomer is 60 parts by mass or more per 100 parts by mass of the monomer component.

[6] The resin composition according to [1] or [5], wherein the content of the second monomer is 25 parts by mass or less with respect to 100 parts by mass of the monomer component.

[7] The resin composition according to [2], wherein the content of the first structural unit is 60 parts by mass or more per 100 parts by mass of all structural units constituting the acrylic resin.

[8] The resin composition according to [2] or [7], wherein the content of the second structural unit is 25 parts by mass or less with respect to 100 parts by mass of all structural units constituting the acrylic resin.

[9] The resin composition according to any one of [1] to [8], wherein the content of the acrylic resin is 50 parts by mass or more per 100 parts by mass of the resin composition.

[10] The resin composition according to any one of [1] to [9], wherein the reactive group is an epoxy group.

[11] The resin composition according to any one of [1] to [10], which is liquid at 90 ℃.

[12] The resin composition according to [11], wherein the weight average molecular weight of the acrylic resin is 100000 or less.

[13] The resin composition according to [11] or [12], having a viscosity of 100 Pa-s or less at 90 ℃.

[14] The resin composition according to any one of [1] to [10], wherein the weight average molecular weight of the acrylic resin is 200000 or more.

[15] The resin composition according to any one of [1] to [14] used for forming a heat storage material.

[16] The resin composition according to any one of [1] to [14] for use in forming a water repellent material, an anti-frost material, a refractive index adjuster, a lubricant, an adsorbent, a thermosetting stress relaxation material, or a low dielectric material.

[17] A heat storage material comprising a cured product of the resin composition according to any one of [1] to [16 ].

[18] An article, comprising: a heat source; and a cured product of the resin composition according to any one of [1] to [16] which is provided in thermal contact with a heat source.

Effects of the invention

According to one aspect of the present invention, a resin composition that can be suitably used for a heat storage material can be provided. According to another aspect of the present invention, a heat storage material having an excellent heat storage amount can be provided. In addition, the heat storage material according to one aspect of the present invention can suppress liquid leakage at a temperature equal to or higher than the phase transition temperature of the heat storage material, and is excellent in heat resistance.

Drawings

Fig. 1 is a schematic cross-sectional view illustrating a heat storage material according to an embodiment.

Fig. 2 is a schematic cross-sectional view showing a heat control sheet according to an embodiment.

Fig. 3 is a schematic cross-sectional view showing a thermal control material according to an embodiment.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments.

In the present specification, "(meth) acrylate" means "acrylate" and "methacrylate" corresponding thereto, and "(meth) acryloyl" means "acryloyl" and "methacryloyl" corresponding thereto.

The weight average molecular weight (Mw) and the number average molecular weight (Mn) in the present specification refer to values determined using Gel Permeation Chromatography (GPC) under the following conditions and polystyrene as a standard substance.

The measurement device: HLC-8320GPC (manufactured by Tosoh corporation, product name)

Analytical column: TSKgel SuperMultipore HZ-H (3-linked) (product name, manufactured by Tosoh corporation)

Protection column: TSKguardcolumn SuperMP (HZ) -H (manufactured by Tosoh corporation)

Eluent: THF (tetrahydrofuran)

Measurement temperature: 25 deg.C

In the present specification, "excellent heat resistance" means a 1% weight loss temperature of 280 ℃ or higher in the TG-DTA measurement.

One embodiment relates to a resin composition containing an acrylic resin. The acrylic resin is a polymer obtained by polymerizing monomer components including a first monomer and a second monomer.

The first monomer is represented by the following formula (1).

[ solution 3]

In the formula, R¹Represents a hydrogen atom or a methyl group, R²Represents an alkyl group having 12 to 30 carbon atoms.

R²The alkyl group represented by the formula (I) may be linear or branched. R²The number of carbon atoms of the alkyl group is preferably 12 to 28, more preferably 12 to 26, further preferably 12 to 24, and particularly preferably 12 to 22.

In other words, the first monomer is an alkyl (meth) acrylate having a linear or branched alkyl group having 12 to 30 carbon atoms at the end of the ester group. Examples of the first monomer include: dodecyl (meth) acrylate (lauryl (meth) acrylate), tetradecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate), behenyl (meth) acrylate, ditetradecyl (meth) acrylate, hexacosanyl (meth) acrylate, and dioctadecyl (meth) acrylate. These first monomers may be used singly or in combination of two or more. The first monomer is preferably at least one selected from the group consisting of dodecyl (meth) acrylate (lauryl (meth) acrylate), hexadecyl (meth) acrylate, octadecyl (meth) acrylate (stearyl (meth) acrylate), and behenyl (meth) acrylate).

From the viewpoint of obtaining a sufficient heat storage amount when forming the heat storage material, the content of the first monomer is preferably not less than 60 parts by mass, more preferably not less than 80 parts by mass, and for example, may be not more than 98 parts by mass with respect to 100 parts by mass of the monomer component.

The second monomer is a monomer (reactive monomer) that is copolymerizable with the first monomer and has a reactive group. The second monomer contains a group having an ethylenically unsaturated bond (ethylenically unsaturated group) so as to be copolymerizable with the first monomer. Examples of the ethylenically unsaturated group include a (meth) acryloyl group, a vinyl group, and an allyl group. The second monomer is preferably a monomer having a reactive group and a (meth) acryloyl group (a (meth) acrylic monomer having a reactive group).

The reactive group in the second monomer is a group capable of reacting with a curing agent described later, and is, for example, at least one group selected from the group consisting of a carboxyl group, a hydroxyl group, an isocyanate group, an amino group, and an epoxy group. That is, the second monomer is, for example, a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an isocyanate group-containing monomer, an amino group-containing monomer, or an epoxy group-containing monomer.

Examples of the carboxyl group-containing monomer include: (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and the like.

Examples of the hydroxyl group-containing monomer include: hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, and 12-hydroxylauryl (meth) acrylate; hydroxyalkyl cycloalkane (meth) acrylates such as (4-hydroxymethylcyclohexyl) methyl (meth) acrylate, and the like. The hydroxyl group-containing monomer may be hydroxyethyl (meth) acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, or the like.

Examples of the isocyanate group-containing monomer include 2-methacryloyloxyethyl isocyanate, 2-acryloxyethyl isocyanate and the like.

Examples of the amino group-containing monomer include N, N-dimethylaminoethyl (meth) acrylate, N-diethylaminoethyl (meth) acrylate, N-dimethylaminopropyl (meth) acrylate, and N, N-diethylaminopropyl (meth) acrylate.

Examples of the epoxy group-containing monomer include: glycidyl (meth) acrylate, α -ethyl (meth) acrylate, glycidyl (meth) acrylate, α -n-butyl (meth) acrylate, 3, 4-epoxybutyl (meth) acrylate, 4, 5-epoxypentyl (meth) acrylate, 6, 7-epoxyheptyl (meth) acrylate, 3-methyl-3, 4-epoxybutyl (meth) acrylate, 4-methyl-4, 5-epoxypentyl (meth) acrylate, 5-methyl-5, 6-epoxyhexyl (meth) acrylate, glycidyl (, Beta-methylglycidyl (meth) acrylate, beta-methylglycidyl alpha-ethyl (meth) acrylate, and the like.

These second monomers may be used singly or in combination of two or more. From the viewpoint of increasing the options of the curing agent, the second monomer is preferably an epoxy group-containing monomer having an epoxy group as a reactive group, more preferably an epoxy group-containing (meth) acrylic monomer, still more preferably glycidyl (meth) acrylate, and particularly preferably glycidyl methacrylate.

When the weight average molecular weight (described in detail later) of the acrylic resin is not less than 200000, the content of the second monomer is preferably not less than 2 parts by mass, more preferably not less than 3 parts by mass, still more preferably not less than 5 parts by mass, and particularly preferably not less than 8 parts by mass with respect to 100 parts by mass of the monomer component, from the viewpoint of more excellent heat resistance of the heat-accumulative material.

When the weight average molecular weight (details will be described later) of the acrylic resin is 100000 or less, the content of the second monomer is preferably 6 parts by mass or more, more preferably 7 parts by mass or more, and still more preferably 8 parts by mass or more with respect to 100 parts by mass of the monomer component, from the viewpoint of excellent curability of the resin composition.

The content of the second monomer may be 2 parts by mass or more, 25 parts by mass or less, preferably 20 parts by mass or less, more preferably 15 parts by mass or less, further preferably 13 parts by mass or less, and particularly preferably 10 parts by mass or less with respect to 100 parts by mass of the monomer component, regardless of the weight average molecular weight of the acrylic resin (described later in detail), from the viewpoint of excellent heat storage amount of the heat storage material.

The monomer component may further contain other monomers as needed in addition to the first monomer and the second monomer. Examples of other monomers include: alkyl (meth) acrylates having an alkyl group having less than 12 carbon atoms (carbon atoms 1 to 11) at the end of an ester group, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, or butyl (meth) acrylate; and cycloalkyl (meth) acrylates having a cyclic hydrocarbon group at the end of an ester group, such as isobornyl (meth) acrylate and dicyclopentanyl (meth) acrylate. The other monomers may be used singly or in combination of two or more.

In one embodiment, the monomer component contains only a first monomer, a second monomer, and, if necessary, a third monomer, the third monomer being at least one selected from the group consisting of an alkyl (meth) acrylate having an alkyl group with 1 to 11 carbon atoms at the end of an ester group and a cycloalkyl (meth) acrylate having a cyclic hydrocarbon group at the end of an ester group. In other words, in one embodiment, the monomer component does not contain a monomer other than the first monomer, the second monomer, and the third monomer (e.g., a (meth) acrylic monomer having a siloxane skeleton). In one embodiment, the monomer component may contain only the first monomer and the second monomer, and in another embodiment, may contain only the first monomer, the second monomer, and the third monomer.

The acrylic resin can be obtained by polymerizing monomer components including a first monomer, a second monomer, and other monomers used as needed. The polymerization method may be suitably selected from known polymerization methods such as various radical polymerization, and examples thereof include suspension polymerization, solution polymerization, and bulk polymerization. As the polymerization method, in the case where the weight average molecular weight of the acrylic resin is made large (for example, 200000 or more), it is preferable to use a suspension polymerization method, and in the case where the weight average molecular weight of the acrylic resin is made small (for example, 100000 or less), it is preferable to use a solution polymerization method.

In the case of using the suspension polymerization method, a monomer component as a raw material, a polymerization initiator, a chain transfer agent added as needed, water and a suspending agent are mixed to prepare a dispersion.

Examples of the suspending agent include: water-soluble polymers such as polyvinyl alcohol, methyl cellulose, and polyacrylamide; and insoluble inorganic substances such as calcium phosphate and magnesium pyrophosphate. Among these, a water-soluble polymer such as polyvinyl alcohol is preferably used.

The amount of the suspending agent is preferably 0.005 to 1 part by mass, more preferably 0.01 to 0.07 part by mass, based on 100 parts by mass of the total amount of the monomer components as raw materials. When the suspension polymerization method is used, a molecular weight modifier such as a thiol compound, thioglycol, carbon tetrachloride or α -methylstyrene dimer may be further added as necessary. The polymerization temperature is preferably 0 to 200 ℃, more preferably 40 to 120 ℃.

In the case of using the solution polymerization method, examples of the solvent used include: aromatic solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, chlorine solvents such as carbon tetrachloride, and alcohol solvents such as 2-propanol and 2-butanol. The solid content concentration in the solution at the start of the solution polymerization is preferably 40 to 70% by mass, more preferably 50 to 60% by mass, from the viewpoint of polymerizability of the resulting acrylic resin. The polymerization temperature is preferably 0 to 200 ℃, more preferably 40 to 120 ℃.

The polymerization initiator that can be used in each polymerization method is not particularly limited as long as it is a radical polymerization initiator. Examples of the radical polymerization initiator include: organic peroxides such as benzoyl peroxide, lauroyl peroxide, di-t-butyl hydroperoxide terephthalate, t-butyl peroxy-2-ethylhexanoate, 1-t-butylperoxy-3, 3, 5-trimethylcyclohexane, and t-butyl peroxyisopropylcarbonate, and azo compounds such as azobisisobutyronitrile, azobis-4-methoxy-2, 4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitrile, and azobisbenzoyl.

From the viewpoint of sufficiently polymerizing the monomers, the amount of the polymerization initiator to be added is preferably not less than 0.01 part by mass, more preferably not less than 0.05 part by mass, and still more preferably not less than 0.1 part by mass, relative to 100 parts by mass of the total amount of the monomers. The amount of the polymerization initiator to be blended is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 3 parts by mass or less, per 100 parts by mass of the total amount of the monomers, from the viewpoints that the molecular weight of the acrylic resin falls within an appropriate range, the decomposition products can be suppressed, and an appropriate adhesive strength can be obtained when used as a heat storage material.

The acrylic resin obtained as above has a structural unit derived from the first monomer and a structural unit derived from the second monomer. That is, the resin composition according to one embodiment contains an acrylic resin containing a first structural unit (structural unit derived from a first monomer) and a second structural unit (structural unit derived from a second monomer).

The first structural unit is represented by the following formula (2).

[ solution 4]

In the formula, R³Represents a hydrogen atom or a methyl group, R⁴Represents an alkyl group having 12 to 30 carbon atoms.

R⁴The alkyl group represented by the formula (I) may be linear or branched. R⁴The number of carbon atoms of the alkyl group is preferably 12 to 28, more preferably 12 to 26, further preferably 12 to 24, and particularly preferably 12 to 22. As R⁴Examples of the alkyl group include: dodecyl (lauryl), tetradecyl, hexadecyl, octadecyl (stearyl), docosyl (behenyl), tetracosyl, hexacosyl, octacosyl, and the like. R⁴The alkyl group represented is preferably at least one selected from the group consisting of dodecyl (lauryl), hexadecyl, octadecyl (stearyl), and docosyl (behenyl). The acrylic resin contains one or more of these first structural units.

From the viewpoint of excellent heat storage capacity of the heat storage material, the content of the first structural unit is preferably not less than 60 parts by mass, more preferably not less than 80 parts by mass, and for example, may be not more than 98 parts by mass with respect to 100 parts by mass of all the structural units constituting the acrylic resin.

The second structural unit has a reactive group. The reactive group is a group capable of reacting with a curing agent described later, and is, for example, at least one group selected from the group consisting of a carboxyl group, a hydroxyl group, an isocyanate group, an amino group, and an epoxy group. The second structural unit is, for example, a structural unit derived from the above-mentioned carboxyl group-containing monomer, hydroxyl group-containing monomer, isocyanate group-containing monomer, amino group-containing monomer or epoxy group-containing monomer. From the viewpoint of a wide variety of options for the curing agent, the second structural unit preferably has an epoxy group as a reactive group, and more preferably has a glycidyl group. The acrylic resin contains one or two or more of these second structural units.

The second structural unit is preferably a structural unit represented by the following formula (3).

[ solution 5]

In the formula, R⁵Represents a hydrogen atom or a methyl group, R⁶Represents a hydrogen atom or an organic group having a reactive group. R⁶The reactive group represented may be the above-mentioned reactive group, and is preferably an organic group having an epoxy group, and more preferably a glycidyl group.

When the weight average molecular weight (described in detail later) of the acrylic resin is not less than 200000, the content of the second structural unit is preferably not less than 2 parts by mass, more preferably not less than 3 parts by mass, still more preferably not less than 5 parts by mass, and particularly preferably not less than 8 parts by mass, based on 100 parts by mass of all the structural units constituting the acrylic resin, from the viewpoint of more excellent heat resistance of the heat-accumulative material.

When the weight average molecular weight (described in detail later) of the acrylic resin is 100000 or less, the content of the second structural unit is preferably 6 parts by mass or more, more preferably 7 parts by mass or more, and further preferably 8 parts by mass or more with respect to 100 parts by mass of all the structural units constituting the acrylic resin, from the viewpoint of excellent curability of the resin composition.

The content of the second structural unit may be 2 parts by mass or more, preferably 20 parts by mass or less, more preferably 15 parts by mass or less, further preferably 13 parts by mass or less, and particularly preferably 10 parts by mass or less with respect to 100 parts by mass of all the structural units constituting the acrylic resin, from the viewpoint of obtaining a sufficient heat storage amount when forming the heat storage material, regardless of the weight average molecular weight (details will be described later) of the acrylic resin.

The acrylic resin may further contain other structural units as necessary in addition to the first structural unit and the second structural unit. The other structural unit may be a structural unit derived from the above-mentioned other monomer.

In one embodiment, the acrylic resin contains only a first structural unit, a second structural unit, and, if necessary, a third structural unit derived from at least one monomer selected from the group consisting of an alkyl (meth) acrylate having an alkyl group with 1 to 11 carbon atoms at the end of an ester group and a cycloalkyl (meth) acrylate having a cyclic hydrocarbon group at the end of an ester group. In other words, in one embodiment, the acrylic resin does not contain a structural unit (for example, a structural unit derived from a (meth) acrylic monomer having a siloxane skeleton) other than the first structural unit, the second structural unit, and the third structural unit. In one embodiment, the acrylic resin may contain only the first structural unit and the second structural unit, and in another embodiment, may contain only the first structural unit, the second structural unit, and the third structural unit.

The acrylic resin may be any of a random copolymer, a block copolymer, or a graft copolymer.

In one embodiment, the weight average molecular weight of the acrylic resin is preferably 200000 or more, more preferably 250000 or more, and still more preferably 300000 or more, from the viewpoint of excellent strength of the heat-accumulative material. From the viewpoint of ease of handling of the resin composition, the weight average molecular weight of the acrylic resin is preferably not more than 2000000, more preferably not more than 1500000, and still more preferably not more than 1000000.

In another embodiment, the weight average molecular weight of the acrylic resin is preferably 100000 or less, more preferably 70000 or less, and further preferably 40000 or less, from the viewpoint of reducing the viscosity of the resin composition. In this case, the weight average molecular weight of the acrylic resin may be, for example, 5000 or more.

The content of the acrylic resin is preferably not less than 50 parts by mass, more preferably not less than 70 parts by mass, and still more preferably not less than 80 parts by mass, per 100 parts by mass of the resin composition, from the viewpoint of excellent heat storage capacity of the heat storage material. The content of the acrylic resin may be 100 parts by mass or less, 99.5 parts by mass or less, or 99.3 parts by mass or less with respect to 100 parts by mass of the resin composition.

When the resin composition is used for forming a heat storage material, the resin composition further contains a curing agent from the viewpoint of suppressing liquid leakage and volatilization of the heat storage material and improving heat resistance. The curing agent is a curing agent capable of reacting with a reactive group contained in the second monomer (second structural unit). Examples of the curing agent include isocyanate-based curing agents, phenol-based curing agents, amine-based curing agents, imidazole-based curing agents, acid anhydride-based curing agents, and carboxylic acid-based curing agents. These curing agents may be used singly or in combination of two or more. When the reactive group is an epoxy group, the curing agent is preferably a phenol curing agent or an imidazole curing agent.

Examples of the isocyanate curing agent include: toluene diisocyanate (2, 4-toluene diisocyanate or 2, 6-toluene diisocyanate or a mixture Thereof) (TDI), phenylene diisocyanate (m-phenylene diisocyanate or p-phenylene diisocyanate or a mixture thereof), 4 '-diphenyl diisocyanate, 1, 5-Naphthalene Diisocyanate (NDI), diphenylmethane diisocyanate (4,4' -diphenylmethane diisocyanate, 2,4 '-diphenylmethane diisocyanate or 2,2' -diphenylmethane diisocyanate or a mixture thereof) (MDI), 4 '-toluidine diisocyanate (TODI), 4' -diphenyl ether diisocyanate or other aromatic diisocyanates, xylylene diisocyanate (1, 3-xylylene diisocyanate or 1, 4-xylylene diisocyanate or a mixture thereof) (XDI), Tetramethylxylylene diisocyanate (tetramethyl 1, 3-xylylene diisocyanate or tetramethyl 1, 4-xylylene diisocyanate or a mixture Thereof) (TMXDI), omega' -diisocyanate-1, 4-diethylbenzene, and the like. As the isocyanate-based curing agent, there may be mentioned: aliphatic diisocyanates such as trimethylene diisocyanate, 1, 2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1, 2-butylene diisocyanate, 2, 3-butylene diisocyanate, 1, 3-butylene diisocyanate), 1, 5-Pentamethylene Diisocyanate (PDI), 1, 6-Hexamethylene Diisocyanate (HDI), 2,4, 4-trimethylhexamethylene diisocyanate or 2,2, 4-trimethylhexamethylene diisocyanate, methyl 2, 6-diisocyanatohexanoate, 1, 3-cyclopentane diisocyanate, 1, 3-cyclopentene diisocyanate, cyclohexane diisocyanate (1, 4-cyclohexane diisocyanate, 1, 3-cyclohexane diisocyanate), 3-isocyanatomethyl-3, 5, 5-trimethylcyclohexyl isocyanate (isophorone diisocyanate) (IPDI), methylene bis (cyclohexyl isocyanate) (4,4' -methylene bis (cyclohexyl isocyanate), 2,4' -methylene bis (cyclohexyl isocyanate) or 2,2' -methylene bis (cyclohexyl isocyanate), their trans-trans, trans-cis, cis-cis, or mixtures thereof) (H12MDI), methylcyclohexane diisocyanate (methyl-2, 4-cyclohexane diisocyanate, methyl-2, 6-cyclohexane diisocyanate), norbornane diisocyanate (various isomers or mixtures thereof) (NBDI), bis (isocyanatomethyl) cyclohexane (1, alicyclic diisocyanates such as 3-bis (isocyanatomethyl) cyclohexane, 1, 4-bis (isocyanatomethyl) cyclohexane or a mixture thereof) (H6XDI), and the like.

Examples of the phenol-based curing agent include: bisphenol A, bisphenol F, bisphenol S, 4' -biphenol, tetramethylbisphenol A, dimethylbisphenol A, tetramethylbisphenol F, dimethylbisphenol F, tetramethylbisphenol S, dimethylbisphenol S, tetramethyl-4, 4 '-biphenol, dimethyl-4, 4' -biphenol, 1- (4-hydroxyphenyl) -2- [4- (1, 1-bis- (4-hydroxyphenyl) ethyl) phenyl ] propane, 2 '-methylene-bis (4-methyl-6-tert-butylphenol), 4' -butylidene-bis (3-methyl-6-tert-butylphenol), trihydroxyphenylmethane, resorcinol, hydroquinone, pyrogallol, phenols having a diisopropylidene skeleton; phenols having a fluorene skeleton such as 1, 1-bis-4-hydroxyphenylfluorene; cresols; ethyl phenols; butyl phenols; octyl phenols; and various novolac resins such as a novolac resin using various phenols such as bisphenol a, bisphenol F, bisphenol S, and naphthols as raw materials, a phenol novolac resin containing a xylylene skeleton, a phenol novolac resin containing a dicyclopentadiene skeleton, a phenol novolac resin containing a biphenyl skeleton, a phenol novolac resin containing a fluorene skeleton, and a phenol novolac resin containing a furan skeleton.

Examples of the amine-based curing agent include: aromatic amines such as diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenyl ether, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 1, 5-diaminonaphthalene, and m-xylylenediamine; aliphatic amines such as ethylenediamine, diethylenediamine, isophoronediamine, bis (4-amino-3-methyldicyclohexyl) methane, and polyetherdiamine; guanidines such as dicyandiamide and 1- (o-tolyl) biguanide.

Examples of the imidazole-based curing agent include: 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2, 3-dihydro-1H-pyrrole- [1,2-a ] benzimidazole, 2, 4-diamino-6 (2 '-methylimidazole (1')) ethyl-s-triazine, 2, 4-diamino-6 (2 '-undecylimidazole (1')) ethyl-s-triazine, 2, 4-diamino-6 (2 '-ethyl, 4-methylimidazole (1')) ethyl-s-triazine, 2, 4-diamino-6 (2 '-methylimidazole (1')) ethyl-s-triazine-isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3, 5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-cyanoethyl-2-phenyl-3, 5-dicyanoethoxymethylimidazole and the like.

Examples of the acid anhydride curing agent include: aromatic carboxylic acid anhydrides such as phthalic anhydride, trimellitic anhydride, pyromellitic dianhydride, benzophenone tetracarboxylic acid anhydride, ethylene glycol anhydrous trimellitic anhydride, and biphenyl tetracarboxylic acid anhydride; anhydrides of aliphatic carboxylic acids such as azelaic acid, sebacic acid, and dodecanedioic acid; and alicyclic carboxylic acid anhydrides such as tetrahydrophthalic anhydride, hexahydrophthalic anhydride, nadic anhydride, chlorendic anhydride, and bicycloheptenedicarboxylic anhydride.

Examples of the carboxylic acid-based curing agent include succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, and terephthalic acid.

The content of the curing agent is preferably not less than 0.01 part by mass, more preferably not more than 10 parts by mass, still more preferably not more than 5 parts by mass, and still more preferably not more than 1 part by mass, per 100 parts by mass of the resin composition.

The resin composition may further contain other additives as needed. Examples of other additives include: curing accelerators, antioxidants, colorants, fillers, crystallization nucleating agents, heat stabilizers, heat conductive materials, plasticizers, foaming agents, flame retardants, vibration dampers, and the like. The other additives may be used singly or in combination of two or more.

From the viewpoint of promoting the reaction between the acrylic resin and the curing agent, the resin composition preferably further contains a curing accelerator. Examples of the curing accelerator include an organophosphorus curing accelerator, a quaternary ammonium salt curing accelerator, and a tin catalyst. These curing accelerators may be used singly or in combination of two or more.

The content of the curing accelerator is preferably not less than 0.005 part by mass, more preferably not less than 0.01 part by mass, still more preferably not less than 0.02 part by mass, and furthermore preferably not more than 1 part by mass, more preferably not more than 0.5 part by mass, and still more preferably not more than 0.2 part by mass, relative to 100 parts by mass of the resin composition.

The resin composition may be in a solid state or a liquid state at 90 ℃, and is preferably in a liquid state from the viewpoints of ease of filling into a member having a complicated shape and a wide range of applications of the heat storage material.

From the viewpoint of excellent fluidity and workability, the viscosity of the resin composition at 90 ℃ is preferably not more than 100 pas, more preferably not more than 50 pas, and still more preferably not more than 20 pas. From the same viewpoint, the viscosity of the resin composition has a viscosity of preferably 100Pa · s or less, more preferably 50Pa · s or less, and further preferably 20Pa · s or less at the melting point of the acrylic resin +20 ℃. The viscosity of the resin composition at 90 ℃ or the viscosity at the melting point of the acrylic resin +20 ℃ may be, for example, 0.5 pas or more.

The viscosity of the resin composition is a value measured in accordance with JIS Z8803, specifically an E-type viscometer (manufactured by Toyobo industries, PE-80L). The viscometer can be calibrated in accordance with JIS Z8809-JS 14000. The melting point of the acrylic resin is a value measured by the method described in examples.

The resin composition described above can be suitably used as a heat storage material (suitably used as a resin composition for a heat storage material) by curing the resin composition. That is, a heat storage material according to one embodiment includes a cured product of the resin composition. In this heat storage material, since the cured product of the acrylic resin functions as a component having heat storage properties, in one embodiment, the heat storage material (resin composition) may not include, for example, a heat storage capsule containing a latent heat storage material used in a conventional heat storage material.

The heat-accumulative material (cured product of the resin composition) can be effectively used in various fields. The heat storage material is used for, for example, air conditioners for automobiles, buildings, public facilities, underground streets, etc. (to improve the efficiency of air conditioners), pipes for factories, etc. (to store heat in pipes), engines for automobiles (to keep the temperature around the engines), electronic components (to prevent the temperature of the electronic components from rising), fibers of underwear, and the like.

In these various applications, the heat storage material (cured product of the resin composition) is disposed in thermal contact with a heat source that generates heat in the various applications, and thus can store the heat of the heat source. That is, one embodiment of the present invention is an article including: a heat source; and a heat storage material (cured product of the resin composition) provided in thermal contact with a heat source.

For example, when the heat storage material (cured product of the resin composition) is used together with an electronic component, the heat storage material is arranged in thermal contact with the electronic component (in direct contact with the electronic component or in contact with the electronic component via a member having thermal conductivity), and thus can store heat generated by the electronic component. In this case, for example, if the heat storage material is disposed in further thermal contact with the heat dissipation member, the heat stored in the heat storage material can be slowly released, and the heat generated by the electronic component can be prevented from being rapidly released to the outside (the local vicinity of the electronic component becomes high temperature).

Fig. 1 is a schematic cross-sectional view illustrating a heat storage material according to an embodiment. As shown in fig. 1, the heat storage material 1 contains a cured product of the resin composition, and may be, for example, a sheet (film) shape.

When the resin composition is solid at 90 ℃, the heat storage material 1 can be obtained by, for example, heating and melting the resin composition and molding the resin composition. That is, in one embodiment, the method for producing the heat storage material 1 includes a step (molding step) of heating and melting the resin composition and molding the resin composition. The molding in the molding process may be injection molding, compression molding or transfer molding. In this case, the heat storage material 1 does not need an outer package, and the heat storage material 1 may be attached to an object to be attached alone, wound, or attached in various states.

In one embodiment, the heat storage material in the case where the resin composition is solid at 90 ℃ can be suitably used for the heat control sheet. Fig. 2 is a schematic cross-sectional view showing a heat control sheet according to an embodiment. As shown in fig. 2, the heat control sheet 2 includes a metal layer 3 and a heat storage layer 4 provided on the metal layer 3.

The metal layer 3 is made of, for example, aluminum, copper, or the like. The thickness of the metal layer 3 is, for example, less than or equal to 100 μm.

The heat storage layer 4 contains the heat storage material 1. The thickness of the heat storage layer 4 is, for example, 1 to 30mm, 2 to 20mm, or 5 to 10 mm.

The heat control sheet 2 can be obtained by, for example, laminating the heat storage material 1 and the metal layer 3 under pressure. In this case, the heat storage material 1 may be heated at a temperature equal to or lower than a temperature at which the shape can be maintained, if necessary.

When the resin composition is liquid at 90 ℃, the heat-accumulative material can be obtained, for example, by filling the resin composition into the voids of the member and then curing the resin composition. That is, in another embodiment, the heat storage material may be obtained by filling a resin composition in the void portion of the member and curing the filled resin composition. In this case, the heat-accumulative material can be formed by filling a liquid resin composition and curing the composition, and thus can be applied to each site, for example, the irregular shape can be suitably applied between members.

In one embodiment, the heat storage material in the case where the resin composition is in a liquid state at 90 ℃ can be suitably used for the heat control material. Fig. 3 is a schematic cross-sectional view for explaining a thermal control material according to an embodiment. As shown in fig. 3(b), the thermal control material 15 includes a plurality of metal layers (metal members) 13 and a heat storage layer 14 filled (provided) between the plurality of metal layers 13. The metal layer 13 and the heat storage layer 14 may have the same structure as the metal layer 3 and the heat storage layer 4 in the heat control sheet. The metal layer 13 may have a concavo-convex shape. The thermal control material 15 may further include a void 11 between some of the metal layers 13 and 13. The gap 11 functions as an air cooling passage through which air for air cooling passes, for example.

As shown in fig. 3(a), the thermal control material 15 can be obtained, for example, by: in a metal member 10 having a plurality of metal layers 13 and a plurality of voids 11 provided between some of the metal layers 13, a liquid resin composition 12 is filled in a part of the voids 11, and then the resin composition 12 is cured.

In the thermal control sheet 2 and the thermal control material 15, the reflectance of sunlight becomes high at a high temperature (for example, 20 ℃ C. or higher) and the reflectance of sunlight becomes low at a low temperature (for example, 15 ℃ C. or lower). The heat control sheet 2 and the heat control material 15 can be used for, for example, a roof, a road, or the like. By laying the heat control sheet 2 or the heat control material 15 on a roof, a road, or the like, the heat storage layers 4 and 14 become transparent at high temperatures (e.g., summer), and the metal layers 3 and 13 reflect solar heat, whereby the heat control sheet 2 or the heat control material 15 can suppress temperature increase of the roof, the road, or the like. On the other hand, in the case where the heat storage layers 4 and 14 become opaque at low temperatures (e.g., in winter), the metal layers 3 and 13 do not reflect solar heat, and the heat storage layers 4 and 14 absorb heat, thereby suppressing a temperature drop in a roof, a road, or the like. That is, the thermal control sheet 2 and the thermal control material 15 can achieve suppression of temperature rise at high temperatures and suppression of temperature drop at low temperatures, and can be effectively used as an auxiliary function of an air conditioner.

In another embodiment, the resin composition may be used for other applications than heat-accumulative materials. The resin composition can be suitably used for forming, for example, a water repellent material, an anti-frost material, a refractive index adjuster, a lubricant material, an adsorbent material, a thermosetting stress relaxation material, or a low dielectric material. The water repellent material, the frost-proof material, the refractive index adjuster, the lubricant material, the adsorbent material, the thermosetting stress relaxation material, and the low dielectric material may each contain, for example, a cured product of the above resin composition.