Method for manufacturing a double-sided mounting substrate

Abstract

To provide a new double-sided mounting board manufacturing method.SOLUTION: A double-sided mounting board manufacturing method includes a first mounting step of mounting a first electronic component on a first main surface of a substrate having the first main surface and a second main surface, a holding step of arranging a holding member that holds the first electronic component on the first main surface, and a second mounting step of mounting a second electronic component on the second main surface, and a heat insulating material is disposed so as to surround the first electronic component mounted on the first main surface before the second mounting step.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a double-sided mounting substrate.

Background Art

[0002] Conventionally, various methods for manufacturing a double-sided mounting substrate by mounting components on both sides of a substrate have been studied (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a novel method for manufacturing a double-sided mounting substrate.

Means for Solving the Problems

[0005] One aspect of the present invention includes a first mounting step of mounting a first electronic component on the first main surface of a substrate having a first main surface and a second main surface, a holding step of disposing a holding member for holding the first electronic component on the first main surface, and a second mounting step of mounting a second electronic component on the second main surface, and before the second mounting step, a heat insulating material is disposed so as to surround the first electronic component mounted on the first main surface. The present invention relates to a method for manufacturing a double-sided mounting substrate.

[0006] The manufacturing method according to one aspect may further include a covering step of covering the first electronic component with a heat insulating material after the first mounting step, and the holding member may be a member that holds the first electronic component covered with the heat insulating material on the first main surface.

[0007] In one aspect, the holding step may be a step of arranging a holding member including a substrate and a heat insulating layer containing a heat insulating material disposed on the substrate.

[0008] In one aspect, the heat insulating material may contain aerogel particles and may further contain a water-soluble polymer having a hydrophobic group.

[0009] In one aspect, the heat insulating material may be a heat insulating material satisfying the following formula (A). F1>F2 …(A) [In the formula, F1 represents the adhesive force of the heat insulating material after heating the heat insulating material at 220°C for 120 seconds, and F2 represents the adhesive force of the heat insulating material after heating the heat insulating material at 260°C for 30 seconds.]

[0010] In one aspect, the heat insulating material may contain first hollow particles that are thermally expandable hollow particles, second hollow particles that are hollow particles other than the first hollow particles, and a matrix polymer.

[0011] Another aspect of the present invention relates to a holding member that holds a first electronic component mounted on the first main surface of a substrate having a first main surface and a second main surface on the first main surface when a second electronic component is mounted on the second main surface, the holding member including a substrate and a heat insulating layer containing a heat insulating material disposed on the substrate.

Advantages of the Invention

[0012] According to the present invention, a novel method for manufacturing a double-sided mounting substrate is provided.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0014] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0015] The method for manufacturing a double-sided mounting substrate according to this embodiment includes a first mounting step of mounting a first electronic component on a first main surface of a substrate having a first main surface and a second main surface, a holding step of disposing a holding member for holding the first electronic component on the first main surface, and a second mounting step of mounting a second electronic component on the second main surface. In the manufacturing method of this embodiment, before the second mounting step, a heat insulating material is disposed so as to surround the first electronic component mounted on the first main surface.

[0016] In the manufacturing method of this embodiment, during the second mounting step, the mounted first electronic component is protected by the heat insulating material. Therefore, even when a high-temperature treatment such as reflow is performed in the second mounting step, connection failures due to remelting of the connection portion between the first electronic component and the substrate, deterioration of the first electronic component due to repeated heating, etc. can be avoided, and it is considered that a double-sided mounting substrate with excellent reliability can be obtained.

[0017] In recent years, lead-free solder has been widely used for connecting electronic components and substrates, and the process temperature has been increasing. In such a high-temperature process, problems due to reheating of the mounted electronic components are more likely to occur. Therefore, it is considered that the effects of the manufacturing method according to this embodiment can be obtained more remarkably.

[0018] The first electronic component may include solder bumps, and the solder bumps may contain lead-free solder. The first mounting step may be, for example, a step of connecting the first electronic component and the substrate via the solder bumps.

[0019] The first implementation step may include a first reflow step of melting solder bumps by reflow to connect the substrate and the first electronic component. In the first reflow step, the substrate and the first electronic component are connected by a connection portion containing solder.

[0020] The reflow temperature may be, for example, a temperature equal to or higher than the melting point of the solder constituting the solder bumps. The reflow temperature may be, for example, 220°C or higher, may be 225°C or higher, may be, for example, 270°C or lower, and may be 260°C or lower. When the solder constituting the solder bumps is lead-free solder, the reflow temperature may be, for example, 240°C or higher, may be 245°C or higher, may be, for example, 260°C or lower, and may be 255°C or lower.

[0021] The first implementation step may further include a first sealing step of sealing the gap between the substrate and the first electronic component with an underfill material. In the first sealing step, the gap between the substrate and the first electronic component is filled with a sealing material made of an underfill material or a cured product thereof.

[0022] The underfill material is not particularly limited, and known underfill materials can be used without particular limitation.

[0023] The holding member is a member that holds the first electronic component on the first main surface in order to prevent the mounted first electronic component from falling off the substrate.

[0024] In the manufacturing method of the present embodiment, for example, after performing the first implementation step with the first main surface on the upper side, the substrate can be turned over and the second implementation step can be performed with the second main surface on the upper side. The holding member may be, for example, a member that supports the first electronic component on the side opposite to the substrate in order to prevent the first electronic component from falling off the first main surface in the second implementation step.

[0025] The second electronic component may be provided with solder bumps, and the solder bumps may contain lead-free solder. The second mounting step may be, for example, a step of connecting the second electronic component and the substrate via the solder bumps.

[0026] The second mounting step may include a second reflow step of melting the solder bumps by reflow to connect the substrate and the second electronic component. In the second reflow step, the substrate and the second electronic component are connected by a connection portion containing solder.

[0027] The reflow temperature may be, for example, a temperature equal to or higher than the melting point of the solder constituting the solder bumps. The reflow temperature may be, for example, 220°C or higher, may be 225°C or higher, may be, for example, 270°C or lower, or may be 260°C or lower. When the solder constituting the solder bumps is lead-free solder, the reflow temperature may be, for example, 240°C or higher, may be 245°C or higher, may be, for example, 260°C or lower, or may be 255°C or lower.

[0028] The second mounting step may further include a second sealing step of sealing the gap between the substrate and the second electronic component with an underfill material. In the second sealing step, the gap between the substrate and the second electronic component is filled with a sealing material made of an underfill material or a cured product thereof.

[0029] The underfill material is not particularly limited, and known underfill materials can be used without particular limitation.

[0030] In the manufacturing method of the present embodiment, before the second mounting step, a heat insulating material is disposed so as to surround the first electronic component mounted on the first main surface.

[0031] The arrangement of the heat insulating material may be carried out, for example, by covering the mounted first electronic component with the heat insulating material. That is, the manufacturing method of the present embodiment may further include a covering step of covering the mounted first electronic component with the heat insulating material.

[0032] Further, the arrangement of the heat insulating material may be carried out, for example, by using a holding member containing the heat insulating material. That is, in the manufacturing method of the present embodiment, the holding step may be a step of arranging a holding step containing the heat insulating material.

[0033] The holding member containing the heat insulating material may be, for example, a holding member including a substrate and a heat insulating layer containing the heat insulating material disposed on the substrate. Such a holding member may be, for example, a known holding member with a heat insulating layer containing the heat insulating material disposed on at least one surface thereof.

[0034] As the heat insulating material, a known heat insulating material can be used without particular limitation.

[0035] Examples of the heat insulating material suitable in the present embodiment include the following heat insulating materials.

[0036] [Heat insulating material (1)] The heat insulating material may be, for example, a heat insulating material containing aerogel particles (hereinafter, heat insulating material (1)). The heat insulating material (1) containing aerogel particles may be, for example, a coating film of a coating liquid containing aerogel particles.

[0037] The coating liquid containing aerogel particles includes aerogel particles and a liquid medium. The pores in the aerogel particles may be filled with the liquid medium.

[0038] [Aerogel] Narrowly defined, the dry gel obtained by using the supercritical drying method for a wet gel is called an aerogel, the dry gel obtained by drying under atmospheric pressure is called a xerogel, and the dry gel obtained by freeze-drying is called a cryogel. However, in this embodiment, regardless of these drying methods for the wet gel, the obtained low-density dry gel is referred to as an "aerogel". That is, in this embodiment, "aerogel" means a broadly defined aerogel, "Gelcomprised of amicroporous solid inwhich the dispersedphase is a gas (a gel composed of a microporous solid in which the dispersed phase is a gas)". Generally, the inside of an aerogel has a network-like fine structure and has a cluster structure in which particulate aerogel components of about 2 to 20 nm are bonded. There are pores of less than 100 nm between the skeletons formed by this cluster. As a result, the aerogel has a three-dimensionally fine porous structure. Note that the aerogel according to this embodiment is, for example, a silica aerogel mainly composed of silica. Examples of the silica aerogel include so-called organo-inorganic hybridized silica aerogels into which an organic group (such as a methyl group) or an organic chain is introduced.

[0039] Examples of the aerogel according to this embodiment include the following aspects. By adopting these aspects, it becomes easy to obtain an aerogel excellent in heat insulation, flame retardancy, heat resistance, and flexibility. By adopting each aspect, an aerogel having heat insulation, flame retardancy, heat resistance, and flexibility corresponding to each aspect can be obtained.

[0040] (First aspect) The aerogel according to this embodiment can have a structure represented by the following general formula (1). The aerogel according to this embodiment can have a structure represented by the following general formula (1a) as a structure including the structure represented by formula (1).

Chemical formula

Chemical formula

[0041] In Formula (1) and Formula (1a), R 1 and R 2 each independently represent an alkyl group or an aryl group, and R 3 and R 4 each independently represent an alkylene group. Here, examples of the aryl group include a phenyl group and a substituted phenyl group. Examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group. p represents an integer of 1 to 50. In Formula (1a), two or more R 1 may be the same or different from each other. Similarly, two or more R 2 may be the same or different from each other. In Formula (1a), two R 3 may be the same or different from each other. Similarly, two R 4 may be the same or different from each other.

[0042] By introducing the structure represented by the above Formula (1) or Formula (1a) into the skeleton of the aerogel as an aerogel component, an aerogel having a low thermal conductivity and flexibility can be obtained. From such a viewpoint, in Formula (1) and Formula (1a), R 1 and R 2 each independently include an alkyl group having 1 to 6 carbon atoms, a phenyl group, etc., and examples of the alkyl group include a methyl group, etc. Further, in Formula (1) and Formula (1a), R 3 and R 4 each independently include an alkylene group having 1 to 6 carbon atoms, etc., and examples of the alkylene group include an ethylene group, a propylene group, etc. In Formula (1a), p can be 2 to 30, and may be 5 to 20.

[0043] (Second Aspect) The aerogel according to this embodiment has a ladder-type structure including strut portions and bridging portions, and the bridging portions can have a structure represented by the following general formula (2). By introducing such a ladder-type structure as an aerogel component into the skeleton of the aerogel, heat resistance and mechanical strength can be improved. In this embodiment, the "ladder-type structure" means a structure having two strut portions and bridging portions connecting the strut portions (a structure having the form of a so-called "ladder"). In this aspect, the skeleton of the aerogel may be composed of a ladder-type structure, or the aerogel may partially have a ladder-type structure. [Chemical formula]

[0044] In formula (2), R 5 and R 6 each independently represent an alkyl group or an aryl group, and b represents an integer of 1 to 50. Here, examples of the aryl group include a phenyl group and a substituted phenyl group. Examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group. In formula (2), when b is an integer of 2 or more, two or more R 5 may be the same or different from each other, and similarly, two or more R 6 may also be the same or different from each other.

[0045] By introducing the above structure as an aerogel component into the skeleton of the aerogel, for example, an aerogel having flexibility superior to that of an aerogel having a structure derived from a conventional ladder-type silsesquioxane (that is, having a structure represented by the following general formula (X)) is obtained. Silsesquioxane has a compositional formula: (RSiO 1.5 ) nIt is a polysiloxane having, and can have various skeletal structures such as cage type, ladder type, random type, etc. As shown by the following general formula (X), in the aerogel having a structure derived from a conventional ladder type silsesquioxane, the structure of the bridging part is -O-, but in the aerogel according to the present embodiment, the structure of the bridging part is the structure represented by the above general formula (2) (polysiloxane structure). However, the aerogel of this aspect may have a structure derived from silsesquioxane in addition to the structure represented by the general formula (2). [Chemical formula]

[0046] In formula (X), R represents a hydroxy group, an alkyl group or an aryl group.

[0047] The structure of the column part, its chain length, and the interval of the structure of the bridging part are not particularly limited, but from the viewpoint of further improving heat resistance and mechanical strength, as the ladder type structure, it may have a ladder type structure represented by the following general formula (3). [Chemical formula]

[0048] In formula (3), R 5 , R 6 , R 7 and R 8 each independently represent an alkyl group or an aryl group, a and c each independently represent an integer of 1 to 3000, and b represents an integer of 1 to 50. Here, examples of the aryl group include a phenyl group, a substituted phenyl group, etc. Examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, a cyano group, etc. In formula (3), when b is an integer of 2 or more, two or more R 5 may be the same or different from each other, and similarly, two or more R 6 may also be the same or different from each other. In formula (3), when a is an integer of 2 or more, two or more R 7may be the same or different from each other. Similarly, when c is an integer of 2 or more, two or more Rs 8 may be the same or different from each other.

[0049] From the viewpoint of obtaining better flexibility, in formulas (2) and (3), R 5 , R 6 , R 7 and R 8 (however, R 7 and R 8 are only in formula (3)) may each independently be an alkyl group having 1 to 6 carbon atoms, a phenyl group, etc., and examples of the alkyl group include a methyl group. Further, in formula (3), a and c can each independently be 6 to 2000, but may be 10 to 1000. Further, in formulas (2) and (3), b can be 2 to 30, but may be 5 to 20.

[0050] (Third Aspect) The aerogel according to this embodiment may be a dried product of a wet gel (obtained by drying a wet gel generated from a sol) that is a condensate of a sol containing at least one selected from the group consisting of a silicon compound having a hydrolyzable functional group or a condensable functional group, and a hydrolysis product of a silicon compound having a hydrolyzable functional group. Note that the aerogels described so far may also be obtained by drying a wet gel generated from a sol containing a silicon compound or the like.

[0051] As the silicon compound having a hydrolyzable functional group or a condensable functional group, a polysiloxane compound can be used. That is, the above sol can contain at least one compound selected from the group consisting of a polysiloxane compound having a hydrolyzable functional group or a condensable functional group, and a hydrolysis product of a polysiloxane compound having a hydrolyzable functional group (hereinafter, sometimes referred to as the "polysiloxane compound group").

[0052] The functional groups in the polysiloxane compound are not particularly limited, but they can be groups that react with the same functional groups or groups that react with other functional groups. Examples of the hydrolyzable functional group include an alkoxy group. Examples of the condensable functional group include a hydroxyl group, a silanol group, a carboxyl group, a phenolic hydroxyl group, etc. The hydroxyl group may be contained in a hydroxyl group-containing group such as a hydroxyalkyl group. Note that the polysiloxane compound having a hydrolyzable functional group or a condensable functional group may further have a reactive group different from the hydrolyzable functional group and the condensable functional group (a functional group not corresponding to the hydrolyzable functional group and the condensable functional group). Examples of the reactive group include an epoxy group, a mercapto group, a glycidoxy group, a vinyl group, an acryloyl group, a methacryloyl group, an amino group, etc. The epoxy group may be contained in an epoxy group-containing group such as a glycidoxy group. The polysiloxane compounds having these functional groups and reactive groups may be used alone or in combination of two or more. Among these functional groups and reactive groups, for example, groups that improve the flexibility of the aerogel include an alkoxy group, a silanol group, a hydroxyalkyl group, etc. Among these, the alkoxy group and the hydroxyalkyl group can further improve the compatibility of the sol. Also, from the viewpoint of improving the reactivity of the polysiloxane compound and reducing the thermal conductivity of the aerogel, the carbon number of the alkoxy group and the hydroxyalkyl group can be 1 to 6, but may be 2 to 4 from the viewpoint of further improving the flexibility of the aerogel.

[0053] Examples of the polysiloxane compound having a hydroxyalkyl group in the molecule include those having a structure represented by the following general formula (A). By using the polysiloxane compound having a structure represented by the following general formula (A), the structures represented by the general formula (1) and the formula (1a) can be introduced into the skeleton of the aerogel.

Chemical formula

[0054] In formula (A), R 1a represents a hydroxyalkyl group, R 2arepresents an alkylene group, and R 3a and R 4a each independently represent an alkyl group or an aryl group, and n represents an integer from 1 to 50. Here, examples of the aryl group include a phenyl group and a substituted phenyl group. Examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, and a cyano group. In formula (A), the two R 1a may be the same or different from each other, and similarly, the two R 2a may be the same or different from each other. Also, in formula (A), two or more R 3a may be the same or different from each other, and similarly, two or more R 4a may be the same or different from each other.

[0055] By using a wet gel (formed from a sol) that is a condensate of a sol containing the polysiloxane compound having the above structure, it becomes easier to obtain an aerogel with low thermal conductivity and flexibility. From such a perspective, in formula (A), examples of R 1a include a hydroxyalkyl group having 1 to 6 carbon atoms, and examples of the hydroxyalkyl group include a hydroxyethyl group and a hydroxypropyl group. Also, in formula (A), examples of R 2a include an alkylene group having 1 to 6 carbon atoms, and examples of the alkylene group include an ethylene group and a propylene group. Also, in formula (A), examples of R 3a and R 4a each independently include an alkyl group having 1 to 6 carbon atoms, a phenyl group, etc., and examples of the alkyl group include a methyl group. Also, in formula (A), n can be from 2 to 30, but may also be from 5 to 20.

[0056] As the polysiloxane compound having the structure represented by the above general formula (A), commercially available products can be used, such as compounds such as X-22-160AS, KF-6001, KF-6002, KF-6003 (all manufactured by Shin-Etsu Chemical Co., Ltd.), compounds such as XF42-B0970, FluidOFOH 702-4% (all manufactured by Momentive Performance Materials Japan LLC), and the like.

[0057] As the polysiloxane compound having an alkoxy group in the molecule, those having the structure represented by the following general formula (B) can be mentioned. By using the polysiloxane compound having the structure represented by the following general formula (B), a ladder-type structure having a bridging portion represented by the general formula (2) or (3) can be introduced into the skeleton of the aerogel.

Chemical formula

[0058] In formula (B), R 1b represents an alkyl group, an alkoxy group or an aryl group, R 2b and R 3b each independently represents an alkoxy group, R 4b and R 5b each independently represents an alkyl group or an aryl group, and m represents an integer of 1 to 50. Here, examples of the aryl group include a phenyl group and a substituted phenyl group. Further, examples of the substituent of the substituted phenyl group include an alkyl group, a vinyl group, a mercapto group, an amino group, a nitro group, a cyano group, and the like. In formula (B), the two R 1b may be the same or different from each other, the two R 2b may be the same or different from each other, and similarly, the two R 3b may be the same or different from each other. Also, in formula (B), when m is an integer of 2 or more, two or more R 4b may be the same or different from each other, and similarly, two or more R 5b may also be the same or different from each other.

[0059] By using a wet gel (formed from a sol) that is a condensate of a sol containing the polysiloxane compound having the above structure or a hydrolysis product thereof, it becomes easier to further obtain an aerogel with low thermal conductivity and flexibility. From such a perspective, in formula (B), examples of R1b include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, etc., and examples of the alkyl group or alkoxy group include a methyl group, a methoxy group, an ethoxy group, etc. Further, in formula (B), examples of R2b and R3b each independently include an alkoxy group having 1 to 6 carbon atoms, etc., and examples of the alkoxy group include a methoxy group, an ethoxy group, etc. Further, in formula (B), examples of R4b and R5b each independently include an alkyl group having 1 to 6 carbon atoms, a phenyl group, etc., and examples of the alkyl group include a methyl group, etc. Further, in formula (B), m can be 2 to 30, but may also be 5 to 20.

[0060] The polysiloxane compound having the structure represented by the above general formula (B) can be obtained by appropriately referring to the production methods reported in JP-A-2000-26609, JP-A-2012-233110, etc. Further, XR31-B1410 (manufactured by Momentive) can also be used as the polysiloxane compound.

[0061] Note that since the alkoxy group undergoes hydrolysis, a polysiloxane compound having an alkoxy group may exist as a hydrolysis product in the sol, and the polysiloxane compound having an alkoxy group and its hydrolysis product may be mixed. Further, in a polysiloxane compound having an alkoxy group, all of the alkoxy groups in the molecule may be hydrolyzed, or may be partially hydrolyzed.

[0062] These polysiloxane compounds having a hydrolyzable functional group or a condensable functional group, and hydrolysis products of polysiloxane compounds having a hydrolyzable functional group may be used alone or in a mixture of two or more.

[0063] In preparing the aerogel according to this embodiment, as the silicon compound having a hydrolyzable functional group or a condensable functional group, a silicon compound other than the above-mentioned polysiloxane compound can be used. That is, the sol containing the above silicon compound can contain at least one selected from the group consisting of a silicon compound having a hydrolyzable functional group or a condensable functional group (excluding the polysiloxane compound), and a hydrolysis product of the silicon compound having a hydrolyzable functional group (hereinafter, sometimes referred to as the "silicon compound group") in addition to the above-mentioned polysiloxane compound group or instead of the above-mentioned polysiloxane compound group. The number of silicon atoms in the molecule of the silicon compound can be 1 or 2.

[0064] The silicon compound having a hydrolyzable functional group in the molecule is not particularly limited, and examples thereof include alkyl silicon alkoxides. From the viewpoint of improving water resistance, the number of hydrolyzable functional groups in the alkyl silicon alkoxide can be 3 or less. Examples of such alkyl silicon alkoxides include monoalkyltrialkoxysilane, monoalkyldialkoxysilane, dialkyldialkoxysilane, monoalkylmonoalkoxysilane, dialkylmonoalkoxysilane, trialkylmonoalkoxysilane, etc., and specifically, methyltrimethoxysilane, methyldimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, etc. Here, examples of the hydrolyzable functional group include alkoxy groups such as methoxy group and ethoxy group.

[0065] The silicon compound having a condensable functional group is not particularly limited, and examples thereof include silanetriol, methylsilanetriol, dimethylsilanediol, phenylsilanetriol, phenylmethylsilanediol, diphenylsilanediol, n-propylsilanetriol, hexylsilanetriol, octylsilanetriol, decylsilanetriol, trifluoropropylsilanetriol, etc.

[0066] A silicon compound having a hydrolyzable functional group or a condensable functional group may further have the above-described reactive group (a functional group not corresponding to the hydrolyzable functional group and the condensable functional group) different from the hydrolyzable functional group and the condensable functional group.

[0067] When the number of hydrolyzable functional groups is 3 or less, as the silicon compound having a reactive group, vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, etc. can also be used.

[0068] Also, as the silicon compound having a condensable functional group and a reactive group, vinylsilanetriol, 3-glycidoxypropylsilanetriol, 3-glycidoxypropylmethylsilanediol, 3-methacryloxypropylsilanetriol, 3-methacryloxypropylmethylsilanediol, 3-acryloxypropylsilanetriol, 3-mercaptopropylsilanetriol, 3-mercaptopropylmethylsilanediol, N-phenyl-3-aminopropylsilanetriol, N-2-(aminoethyl)-3-aminopropylmethylsilanediol, etc. can also be used.

[0069] Furthermore, bistrimethoxysilylmethane, bistrimethoxysilylethane, bistrimethoxysilylhexane, ethyltrimethoxysilane, vinyltrimethoxysilane, etc., which are silicon compounds having 3 or less hydrolyzable functional groups at the molecular terminals, can also be used.

[0070] A silicon compound (excluding polysiloxane compounds) having a hydrolyzable functional group or a condensable functional group, and a hydrolysis product of the silicon compound having a hydrolyzable functional group may be used alone or in combination of two or more.

[0071] By using the above silicon compound (excluding polysiloxane compounds), the structures represented by the following general formulas (4) to (6) can be introduced into the skeleton of the aerogel. The aerogel according to the present embodiment can have any one of these structures alone or two or more.

[0072]

Chemical formula

[0073] In formula (4), R 9 represents an alkyl group. Here, examples of the alkyl group include alkyl groups having 1 to 6 carbon atoms, and examples of the alkyl group include a methyl group.

[0074]

Chemical formula

[0075] In formula (5), R 10 and R 11 each independently represent an alkyl group. Here, examples of the alkyl group include alkyl groups having 1 to 6 carbon atoms, and examples of the alkyl group include a methyl group.

[0076]

Chemical formula

[0077] In formula (6), R 12 represents an alkylene group. Here, examples of the alkylene group include alkylene groups having 1 to 10 carbon atoms, and examples of the alkylene group include an ethylene group and a hexylene group.

[0078] (Fourth Aspect) From the perspective of further strengthening the aerogel according to this embodiment and achieving even better heat insulation and flexibility, in addition to the aerogel component, silica particles may further be contained. The aerogel containing the aerogel component and silica particles may also be referred to as an aerogel composite. The aerogel composite is considered to have a cluster structure that is a characteristic of the aerogel while the aerogel component and silica particles are not complexed, and to have a three-dimensionally fine porous structure.

[0079] The aerogel containing the aerogel component and silica particles can be said to be a dried product of a wet gel that is a condensate of a sol containing at least one selected from the group consisting of the above-described silicon compound having a hydrolyzable functional group or a condensable functional group and a hydrolysis product of a silicon compound having a hydrolyzable functional group, and silica particles. Therefore, the descriptions regarding the first to third aspects can be appropriately applied mutatis mutandis to the aerogel according to this embodiment.

[0080] The silica particles can be used without particular limitation, and examples include amorphous silica particles. Examples of the amorphous silica particles include fused silica particles, fumed silica particles, colloidal silica particles, and the like. Among these, the colloidal silica particles have a high degree of monodispersity and are easily suppressed from aggregating in the sol. Note that the silica particles may be silica particles having a hollow structure, a porous structure, or the like.

[0081] The shape of the silica particles is not particularly limited, and examples include spherical, cocoon-shaped, aggregated types, etc. Among these, by using spherical particles as the silica particles, it becomes easier to suppress aggregation in the sol. The average primary particle diameter of the silica particles may be 1 nm or more, may be 5 nm or more, or may be 20 nm or more from the viewpoint of easily imparting appropriate strength and flexibility to the aerogel and easily obtaining an aerogel excellent in shrinkage resistance during drying. The average primary particle diameter of the silica particles may be 500 nm or less, may be 300 nm or less, or may be 100 nm or less from the viewpoint of easily suppressing the solid heat conduction of the silica particles and easily obtaining an aerogel excellent in heat insulation. From these viewpoints, the average primary particle diameter of the silica particles may be 1 to 500 nm, may be 5 to 300 nm, or may be 20 to 100 nm.

[0082] In the present embodiment, the average particle diameter of the aerogel component and the average primary particle diameter of the silica particles can be obtained by directly observing the aerogel using a scanning electron microscope (hereinafter abbreviated as "SEM"). The "diameter" as used herein means the diameter when the cross-section of the particle exposed on the cross-section of the aerogel is regarded as a circle. Further, the "diameter when the cross-section is regarded as a circle" means the diameter of the perfect circle when the area of the cross-section is replaced with a perfect circle having the same area. In calculating the average particle diameter, the diameter of the circle is determined for 100 particles, and the average thereof is taken.

[0083] Incidentally, the average particle diameter of the silica particles can also be measured from the raw materials. For example, the biaxial average primary particle diameter is calculated as follows from the results of observing 20 arbitrary particles by SEM. That is, taking colloidal silica particles usually dispersed in water with a solid content concentration of about 5 to 40% by mass as an example, after immersing a chip obtained by cutting a wafer with a pattern wiring into a 2 cm square in the dispersion liquid of the colloidal silica particles for about 30 seconds, the chip is rinsed with pure water for about 30 seconds and dried by nitrogen blowing. Then, the chip is placed on a sample stage for SEM observation, a 10 kV accelerating voltage is applied, the silica particles are observed at a magnification of 100,000 times, and an image is taken. Twenty silica particles are arbitrarily selected from the obtained image, and the average of the particle diameters of those particles is taken as the average particle diameter.

[0084] From the viewpoint of easily obtaining an aerogel excellent in shrinkage resistance, the number of silanol groups per gram of the silica particles may be 10×10 18 groups / g or more, may be 50×10 18 groups / g or more, and may be 100×10 18 groups / g or more. From the viewpoint of easily obtaining a homogeneous aerogel, the number of silanol groups per gram of the silica particles may be 1000×10 18 groups / g or less, may be 800×10 18 groups / g or less, and may be 700×10 18 groups / g or less. From these viewpoints, the number of silanol groups per gram of the silica particles may be 10×10 18 ~1000×10 18 groups / g, may be 50×10 18 ~800×10 18 groups / g, and may be 100×10 18 ~700×10 18 groups / g.

[0085] The content of the polysiloxane compound group contained in the above sol (the sum of the content of the polysiloxane compound having a hydrolyzable functional group or a condensable functional group and the content of the hydrolysis product of the polysiloxane compound having a hydrolyzable functional group) may be 5 parts by mass or more, and may be 10 parts by mass or more, from the viewpoint of more easily obtaining good reactivity, based on 100 parts by mass of the total amount of the sol. The content of the polysiloxane compound group contained in the above sol may be 50 parts by mass or less, and may be 30 parts by mass or less, from the viewpoint of more easily obtaining good compatibility, based on 100 parts by mass of the total amount of the sol. From these viewpoints, the content of the polysiloxane compound group contained in the above sol may be 5 to 50 parts by mass, and may be 10 to 30 parts by mass, based on 100 parts by mass of the total amount of the sol.

[0086] When the above sol contains a silicon compound (excluding the polysiloxane compound), the silicon compound group (the sum of the content of the silicon compound having a hydrolyzable functional group or a condensable functional group and the content of the hydrolysis product of the silicon compound having a hydrolyzable functional group) may be 5 parts by mass or more, and may be 10 parts by mass or more, from the viewpoint of more easily obtaining good reactivity, based on 100 parts by mass of the total amount of the sol. The content of the silicon compound group contained in the above sol may be 50 parts by mass or less, and may be 30 parts by mass or less, from the viewpoint of more easily obtaining good compatibility, based on 100 parts by mass of the total amount of the sol. From these viewpoints, the content of the silicon compound group contained in the above sol may be 5 to 50 parts by mass, and may be 10 to 30 parts by mass.

[0087] When the sol contains both a polysiloxane compound group and a silicon compound group, the ratio of the content of the polysiloxane compound group to the content of the silicon compound group may be 1:0.5 or more, and may be 1:1 or more, from the viewpoint that good compatibility is more easily obtained. The ratio of the content of the polysiloxane compound group to the content of the silicon compound group may be 1:4 or less, and may be 1:2 or less, from the viewpoint that shrinkage of the gel is more easily suppressed. From these viewpoints, the ratio of the content of the polysiloxane compound group to the content of the silicon compound group may be 1:0.5 to 1:4, and may be 1:1 to 1:2.

[0088] When the above sol contains silica particles, the content of the silica particles may be 1 part by mass or more, and may be 4 parts by mass or more, based on 100 parts by mass of the total amount of the sol, from the viewpoint that it is easy to impart appropriate strength to the aerogel and it is easy to obtain an aerogel excellent in shrinkage resistance during drying. The content of the silica particles may be 20 parts by mass or less, and may be 15 parts by mass or less, based on 100 parts by mass of the total amount of the sol, from the viewpoint that it is easy to suppress the solid heat conduction of the silica particles and it is easy to obtain an aerogel excellent in heat insulation. From these viewpoints, the content of the silica particles may be 1 to 20 parts by mass, and may be 4 to 15 parts by mass, based on 100 parts by mass of the total amount of the sol.

[0089] <Aerogel particles> The aerogel particles in the present embodiment can be obtained, for example, by pulverizing a bulk aerogel as described later.

[0090] The specific surface area of the aerogel particles can be 350 m 2 / g or less, but may be 300 m 2 / g or less, may be 250 m 2 / g or less, and may be 150 m 2 / g or less. Thereby, it is easy to prepare a coating liquid excellent in film-forming properties. The lower limit of the specific surface area of the aerogel particles is not particularly limited, but from the viewpoints of suppressing aggregation and improving the filling rate in the coating liquid, 30 m 2It can be set to / g degree. Although various methods for adjusting the specific surface area of the aerogel particles can be considered, for example, adjusting the amount of the aerogel component having the bridging structure represented by the general formula (2), adjusting the amount of the silica particles, etc. can be mentioned.

[0091] The specific surface area can be measured by the BET method. As the measuring device, a gas adsorption amount measuring device (manufactured by Quantachrome Instruments Japan Co., Ltd., Autosorb-iQ (Autosorb is a registered trademark)) can be used.

[0092] The average particle diameter D50 of the aerogel particles can be 1 to 1000 μm, but it may be 3 to 700 μm, may be 5 to 500 μm, may be 10 to 100 μm, or may be 10 to 50 μm. When the average particle diameter D50 of the aerogel particles is 1 μm or more, it becomes easier to obtain aerogel particles excellent in dispersibility, handleability, etc. On the other hand, when the average particle diameter D50 is 1000 μm or less, it becomes easier to obtain aerogel particles excellent in dispersibility. The average particle diameter of the aerogel particles can be appropriately adjusted by the pulverization method and pulverization conditions, sieve, classification method, etc.

[0093] The average particle diameter D50 of the aerogel particles can be measured by the laser diffraction / scattering method. For example, the aerogel particles are added to a solvent (ethanol) so that the content of the aerogel particles is 0.05 to 5% by mass, and the aerogel particles are dispersed by vibrating with a 50 W ultrasonic homogenizer for 15 to 30 minutes. Then, about 10 mL of the dispersion liquid is injected into a laser diffraction / scattering type particle size distribution measuring device, and the particle size is measured at 25°C with a refractive index of 1.3 and absorption of 0. And the particle size at the integrated value of 50% (volume basis) in this particle size distribution is taken as the average particle diameter D50. As the measuring device, for example, Microtrac MT3000 (manufactured by Nikkiso Co., Ltd., product name) can be used.

[0094] In addition, commercially available products can also be used as the aerogel particles. Examples of commercially available products of aerogel particles include ENOVA IC3100 (manufactured by CABOT), AeroVa (manufactured by JIOS AEROGEL CORPORATION), and the like.

[0095] <Method for manufacturing aerogel particles> The method for manufacturing aerogel particles is not particularly limited, but for example, it can be manufactured by the following method.

[0096] The aerogel particles of the present embodiment can be manufactured by a manufacturing method mainly comprising a sol generation step, a wet gel generation step of gelling the sol obtained in the sol generation step and then aging to obtain a wet gel, a washing and solvent substitution step of washing and (if necessary) substituting the solvent of the wet gel obtained in the wet gel generation step, a drying step of drying the washed and solvent-substituted wet gel, and a pulverization step of pulverizing the aerogel obtained by drying.

[0097] Alternatively, it may be manufactured by a manufacturing method mainly comprising a sol generation step, a wet gel generation step, a wet gel pulverization step of pulverizing the wet gel obtained in the wet gel generation step, a washing and solvent substitution step, and a drying step.

[0098] The obtained aerogel particles can be further sized uniformly by sieving, classification, etc. The dispersibility can be improved by adjusting the particle size. Note that a "sol" is a state before the gelation reaction occurs, and in the present embodiment, it means a state in which the above silicon compound and optionally silica particles are dissolved or dispersed in a solvent. Also, a wet gel means a gel solid in a wet state that does not have fluidity while containing a liquid medium.

[0099] (Sol generation step) The sol generation step is a step of generating a sol by mixing a silicon compound and, optionally, silica particles (which may be a solvent containing silica particles) and performing a hydrolysis reaction. In this step, an acid catalyst may be further added to the solvent in order to accelerate the hydrolysis reaction. Also, as shown in Japanese Patent No. 5250900, a surfactant, a thermally hydrolyzable compound, etc. can be added to the solvent. Furthermore, for the purpose of suppressing heat ray radiation, etc., components such as carbon graphite, aluminum compounds, magnesium compounds, silver compounds, titanium compounds, etc. may be added to the solvent.

[0100] As the solvent, for example, water or a mixture of water and alcohol can be used. Examples of the alcohol include methanol, ethanol, n-propanol, 2-propanol, n-butanol, 2-butanol, t-butanol, etc. Among these, as alcohols having a low surface tension and a low boiling point in terms of reducing the interfacial tension with the gel wall, methanol, ethanol, 2-propanol, etc. can be mentioned. These may be used alone or in combination of two or more.

[0101] For example, when alcohol is used as the solvent, the amount of alcohol can be 4 to 8 moles with respect to 1 mole of the total amount of the silicon compound group and the polysiloxane compound group, but it may be 4 to 6.5, or may be 4.5 to 6 moles. By setting the amount of alcohol to 4 moles or more, it becomes easier to obtain better compatibility, and by setting it to 8 moles or less, it becomes easier to further suppress the shrinkage of the gel.

[0102] Examples of the acid catalyst include inorganic acids such as hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, hypophosphorous acid, bromic acid, chloric acid, chlorous acid, and hypochlorous acid; acid phosphates such as acidic aluminum phosphate, acidic magnesium phosphate, and acidic zinc phosphate; and organic carboxylic acids such as acetic acid, formic acid, propionic acid, oxalic acid, malonic acid, succinic acid, citric acid, malic acid, adipic acid, and azelaic acid. Among these, organic carboxylic acids are mentioned as acid catalysts that can further improve the water resistance of the resulting aerogel. Examples of the organic carboxylic acid include acetic acid, but formic acid, propionic acid, oxalic acid, malonic acid, etc. may also be used. These may be used alone or in combination of two or more.

[0103] By using an acid catalyst, the hydrolysis reaction of the silicon compound can be promoted, and a sol can be obtained in a shorter time.

[0104] The addition amount of the acid catalyst can be 0.001 to 0.1 parts by mass with respect to 100 parts by mass of the total amount of the polysiloxane compound group and the silicon compound group.

[0105] As the surfactant, a nonionic surfactant, an ionic surfactant, etc. can be used. These may be used alone or in combination of two or more.

[0106] Examples of the nonionic surfactant include compounds containing a hydrophilic part such as polyoxyethylene and a hydrophobic part mainly composed of an alkyl group, and compounds containing a hydrophilic part such as polyoxypropylene. Examples of the compounds containing a hydrophilic part such as polyoxyethylene and a hydrophobic part mainly composed of an alkyl group include polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene alkyl ether. Examples of the compounds containing a hydrophilic part such as polyoxypropylene include polyoxypropylene alkyl ether and block copolymers of polyoxyethylene and polyoxypropylene.

[0107] Examples of the ionic surfactant include cationic surfactants, anionic surfactants, amphoteric surfactants, etc. Examples of the cationic surfactant include cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, etc. Examples of the anionic surfactant include sodium dodecylsulfonate, etc. Examples of the amphoteric surfactant include amino acid-based surfactants, betaine-based surfactants, amine oxide-based surfactants, etc. Examples of the amino acid-based surfactant include acylglutamic acid, etc. Examples of the betaine-based surfactant include lauryldimethylaminoacetic acid betaine, stearyldimethylaminoacetic acid betaine, etc. Examples of the amine oxide-based surfactant include lauryldimethylamine oxide, etc.

[0108] These surfactants are considered to act to reduce the difference in chemical affinity between the solvent in the reaction system and the growing siloxane polymer and suppress phase separation in the wet gel formation step described later.

[0109] The addition amount of the surfactant depends on the type of the surfactant or the type and amount of the silicon compound. For example, it can be 1 to 100 parts by mass with respect to 100 parts by mass of the total amount of the polysiloxane compound group and the silicon compound group. Note that the addition amount may be 5 to 60 parts by mass.

[0110] The thermohydrolyzable compound is considered to generate a base catalyst by thermohydrolysis, make the reaction solution basic, and promote the sol-gel reaction in the wet gel formation step described later. Therefore, the thermohydrolyzable compound is not particularly limited as long as it can make the reaction solution basic after hydrolysis, and examples include urea; acid amides such as formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide; cyclic nitrogen compounds such as hexamethylenetetramine, etc. Among these, urea particularly easily obtains the above-mentioned promoting effect.

[0111] The addition amount of the thermally hydrolyzable compound is not particularly limited as long as it can sufficiently promote the sol-gel reaction in the wet gel formation process described later. For example, when urea is used as the thermally hydrolyzable compound, the addition amount can be 1 to 200 parts by mass with respect to 100 parts by mass of the total amount of the polysiloxane compound group and the silicon compound group. Note that the addition amount may also be 2 to 150 parts by mass. By setting the addition amount to 1 part by mass or more, it becomes easier to obtain better reactivity, and by setting it to 200 parts by mass or less, it becomes easier to further suppress the precipitation of crystals and the decrease in gel density.

[0112] The hydrolysis in the sol formation process depends on the types and amounts of the silicon compound, silica particles, acid catalyst, surfactant, etc. in the mixed solution. For example, it may be carried out for 10 minutes to 24 hours in a temperature environment of 20 to 60 °C, or for 5 minutes to 8 hours in a temperature environment of 50 to 60 °C. Thereby, the hydrolyzable functional groups in the silicon compound are sufficiently hydrolyzed, and the hydrolysis products of the silicon compound can be obtained more reliably.

[0113] However, when adding a thermally hydrolyzable compound to the solvent, the temperature environment of the sol formation process may be adjusted to a temperature that suppresses the hydrolysis of the thermally hydrolyzable compound and suppresses the gelation of the sol. The temperature at this time may be any temperature as long as it can suppress the hydrolysis of the thermally hydrolyzable compound. For example, when urea is used as the thermally hydrolyzable compound, the temperature environment of the sol formation process can be 0 to 40 °C, but it may also be 10 to 30 °C.

[0114] (Wet gel formation process) The wet gel formation process is a process of gelling the sol obtained in the sol formation process and then aging it to obtain a wet gel. In this process, a base catalyst can be used to promote gelation.

[0115] Examples of the base catalyst include carbonates such as calcium carbonate, potassium carbonate, sodium carbonate, barium carbonate, magnesium carbonate, lithium carbonate, ammonium carbonate, copper(II) carbonate, iron(II) carbonate, silver(I) carbonate; hydrogen carbonates such as calcium hydrogen carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, ammonium hydrogen carbonate; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide; ammonium compounds such as ammonium hydroxide, ammonium fluoride, ammonium chloride, ammonium bromide; basic sodium phosphate salts such as sodium metaphosphate, sodium pyrophosphate, sodium polyphosphate; aliphatic amines such as allylamine, diallylamine, triallylamine, isopropylamine, diisopropylamine, ethylamine, diethylamine, triethylamine, 2-ethylhexylamine, 3-ethoxypropylamine, diisobutylamine, 3-(diethylamino)propylamine, di-2-ethylhexylamine, 3-(dibutylamino)propylamine, tetramethylethylenediamine, t-butylamine, sec-butylamine, propylamine, 3-(methylamino)propylamine, 3-(dimethylamino)propylamine, 3-methoxyamine, dimethylethanolamine, methyldiethanolamine, diethanolamine, triethanolamine; nitrogen-containing heterocyclic compounds such as morpholine, N-methylmorpholine, 2-methylmorpholine, piperazine and its derivatives, piperidine and its derivatives, imidazole and its derivatives. Among these, ammonium hydroxide (aqueous ammonia) is highly volatile and hardly remains in the aerogel particles after drying, so it is difficult to impair the water resistance and is excellent in terms of economy. The above base catalysts may be used alone or in combination of two or more.

[0116] By using a base catalyst, the dehydration condensation reaction or dealcoholization condensation reaction of the silicon compound and silica particles in the sol can be promoted, and the gelation of the sol can be carried out in a shorter time. Further, a wet gel having higher strength (rigidity) can be obtained thereby. In particular, since ammonia has high volatility and is difficult to remain in the aerogel particles, by using ammonia as the base catalyst, aerogel particles having more excellent water resistance can be obtained.

[0117] The addition amount of the base catalyst can be 0.5 to 5 parts by mass, but may be 1 to 4 parts by mass with respect to 100 parts by mass of the total amount of the polysiloxane compound group and the silicon compound group. By setting it to 0.5 parts by mass or more, gelation can be carried out in a shorter time, and by setting it to 5 parts by mass or less, a decrease in water resistance can be more suppressed.

[0118] The gelation of the sol in the wet gel formation step may be carried out in a sealed container so that the solvent and the base catalyst do not volatilize. The gelation temperature can be 30 to 90°C, but may be 40 to 80°C. By setting the gelation temperature to 30°C or higher, gelation can be carried out in a shorter time, and a wet gel having higher strength (rigidity) can be obtained. Further, by setting the gelation temperature to 90°C or lower, it becomes easier to suppress the volatilization of the solvent (especially alcohol), so that gelation can be carried out while suppressing volume shrinkage.

[0119] The aging in the wet gel formation step may be carried out in a sealed container so that the solvent and the base catalyst do not volatilize. By aging, the bonds of the components constituting the wet gel are strengthened, and as a result, a wet gel having sufficient strength (rigidity) to suppress shrinkage during drying can be obtained. The aging temperature can be 30 to 90°C, but may be 40 to 80°C. By setting the aging temperature to 30°C or higher, a wet gel having higher strength (rigidity) can be obtained, and by setting the aging temperature to 90°C or lower, it becomes easier to suppress the volatilization of the solvent (especially alcohol), so that gelation can be carried out while suppressing volume shrinkage.

[0120] Since it is often difficult to determine the end point of sol gelation, the sol gelation and subsequent aging may be carried out continuously in a series of operations.

[0121] The gelation time and aging time can be appropriately set according to the gelation temperature and aging temperature. When silica particles are contained in the sol, the gelation time can be significantly shortened compared to the case where they are not contained. This is presumably because the silanol groups or reactive groups of the silicon compound in the sol form hydrogen bonds or chemical bonds with the silanol groups of the silica particles. The gelation time can be set to 10 to 120 minutes, but it may also be 20 to 90 minutes. By setting the gelation time to 10 minutes or more, it becomes easier to obtain a homogeneous wet gel, and by setting it to 120 minutes or less, it becomes possible to simplify the cleaning and solvent replacement steps and the subsequent drying step. As for the entire process of gelation and aging, the total time of the gelation time and the aging time can be set to 4 to 480 hours, but it may also be 6 to 120 hours. By setting the total of the gelation time and the aging time to 4 hours or more, a wet gel with higher strength (rigidity) can be obtained, and by setting it to 480 hours or less, it becomes easier to maintain the effect of aging.

[0122] In order to reduce the density of the obtained aerogel particles or increase the average pore diameter, the gelation temperature and aging temperature may be increased within the above range, or the total time of the gelation time and the aging time may be lengthened within the above range. Also, in order to increase the density of the obtained aerogel particles or decrease the average pore diameter, the gelation temperature and aging temperature may be decreased within the above range, or the total time of the gelation time and the aging time may be shortened within the above range.

[0123] (Wet gel pulverization step) When performing the wet gel pulverization step, the wet gel obtained in the wet gel formation step is pulverized. The pulverization can be carried out, for example, by putting the wet gel into a Henschel mixer, or performing the wet gel formation step in the mixer and operating the mixer under appropriate conditions (rotation speed and time). More simply, it can be carried out by putting the wet gel into a sealable container, or performing the wet gel formation step in a sealable container and shaking it for an appropriate time using a shaking device such as a shaker. In addition, if necessary, the particle size of the wet gel can also be adjusted using a jet mill, a roller mill, a bead mill, or the like.

[0124] (Washing and Solvent Replacement Step) The washing and solvent replacement step is a step having a step of washing the wet gel obtained by the wet gel formation step or the wet gel pulverization step (washing step) and a step of replacing the washing liquid in the wet gel with a solvent suitable for the drying conditions (drying step described later) (solvent replacement step). The washing and solvent replacement step can be carried out in a form in which only the solvent replacement step is performed without performing the step of washing the wet gel. However, from the viewpoint of reducing impurities such as unreacted substances and by-products in the wet gel and enabling the production of aerogel particles with higher purity, the wet gel may be washed.

[0125] In the washing step, the wet gel obtained by the wet gel formation step or the wet gel pulverization step is washed. The washing can be repeatedly performed using, for example, water or an organic solvent. At this time, the washing efficiency can be improved by heating.

[0126] As the organic solvent, various organic solvents such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, acetone, methyl ethyl ketone, 1,2-dimethoxyethane, acetonitrile, hexane, toluene, diethyl ether, chloroform, ethyl acetate, tetrahydrofuran, methylene chloride, N, N-dimethylformamide, dimethyl sulfoxide, acetic acid, and formic acid can be used. The above organic solvents can be used alone or in a mixture of two or more.

[0127] In the solvent replacement process described below, in order to suppress the shrinkage of the gel due to drying, a solvent with a low surface tension can be used. However, solvents with low surface tension generally have extremely low mutual solubility with water. Therefore, when a solvent with a low surface tension is used in the solvent replacement process, examples of the hydrophilic organic solvent used as the organic solvent in the washing process include those having high mutual solubility with both water and the solvent with a low surface tension. Note that the hydrophilic organic solvent used in the washing process can serve the role of preliminary replacement for the solvent replacement process. Among the above organic solvents, examples of the hydrophilic organic solvent include methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, and the like. Note that methanol, ethanol, methyl ethyl ketone, etc. are excellent in terms of economy.

[0128] The amount of water or organic solvent used in the washing process can be an amount sufficient to sufficiently replace the solvent in the wet gel and enable washing. This amount can be 3 to 10 times the volume of the wet gel. Washing can be repeated until the water content in the wet gel after washing is 10% by mass or less based on the silica mass.

[0129] The temperature environment in the washing process can be a temperature below the boiling point of the solvent used for washing. For example, when methanol is used, heating can be performed at about 30 to 60°C.

[0130] In the solvent replacement process, in order to suppress the shrinkage of the aerogel in the drying process, the solvent of the washed wet gel is replaced with a predetermined replacement solvent. At this time, the replacement efficiency can be improved by heating. Specifically, as the replacement solvent, in the drying process, when drying is performed at atmospheric pressure at a temperature below the critical point of the solvent used for drying, the low surface tension solvent described below can be mentioned. On the other hand, when performing supercritical drying, examples of the replacement solvent include ethanol, methanol, 2-propanol, dichlorodifluoromethane, carbon dioxide, etc., or a solvent obtained by mixing two or more of these.

[0131] Examples of the low surface tension solvent include solvents having a surface tension of 30 mN / m or less at 20°C. Note that the surface tension may be 25 mN / m or less, or may be 20 mN / m or less. Examples of the low surface tension solvent include aliphatic hydrocarbons such as pentane (15.5), hexane (18.4), heptane (20.2), octane (21.7), 2-methylpentane (17.4), 3-methylpentane (18.1), 2-methylhexane (19.3), cyclopentane (22.6), cyclohexane (25.2), 1-pentene (16.0); aromatic hydrocarbons such as benzene (28.9), toluene (28.5), m-xylene (28.7), p-xylene (28.3); halogenated hydrocarbons such as dichloromethane (27.9), chloroform (27.2), carbon tetrachloride (26.9), 1-chloropropane (21.8), 2-chloropropane (18.1); ethers such as ethyl ether (17.1), propyl ether (20.5), isopropyl ether (17.7), butyl ethyl ether (20.8), 1,2-dimethoxyethane (24.6); ketones such as acetone (23.3), methyl ethyl ketone (24.6), methyl propyl ketone (25.1), diethyl ketone (25.3); esters such as methyl acetate (24.8), ethyl acetate (23.8), propyl acetate (24.3), isopropyl acetate (21.2), isobutyl acetate (23.7), ethyl butyrate (24.6), etc. (the values in parentheses indicate the surface tension at 20°C, and the unit is [mN / m]). Among these, aliphatic hydrocarbons (such as hexane and heptane) have a low surface tension and excellent working environmental properties. Also, among these, by using hydrophilic organic solvents such as acetone, methyl ethyl ketone, and 1,2-dimethoxyethane, it can be used in combination with the organic solvent in the above washing step. Note that among these, a solvent having a boiling point of 100°C or less at normal pressure may be used in view of easy drying in the drying step described later. The above solvents may be used alone or in combination of two or more.

[0132] The amount of the solvent used in the solvent replacement step can be an amount sufficient to fully replace the solvent in the wet gel after washing. This amount can be 3 to 10 times the volume of the wet gel.

[0133] The temperature environment in the solvent replacement step can be a temperature below the boiling point of the solvent used for replacement. For example, when using heptane, heating can be performed at about 30 to 60 °C.

[0134] In addition, when silica particles are contained in the gel, the solvent replacement step is not essential. The presumed mechanism is as follows. That is, the silica particles function as a support for the three-dimensional network-like skeleton, so that the skeleton is supported and the shrinkage of the gel in the drying step is suppressed. Therefore, it is considered that the gel can be directly subjected to the drying step without replacing the solvent used for washing. Thus, by using silica particles, it is possible to simplify the steps from washing and solvent replacement to drying.

[0135] (Drying step) In the drying step, the wet gel washed and (optionally) solvent-replaced as described above is dried. Thereby, an aerogel (aerogel block or aerogel particles) can be obtained. That is, an aerogel obtained by drying the wet gel produced from the above sol can be obtained.

[0136] The drying method is not particularly limited, and known atmospheric pressure drying, supercritical drying, or freeze drying can be used. Among these, from the viewpoint of being easy to produce a low-density aerogel, atmospheric pressure drying or supercritical drying can be used. Also, from the viewpoint of being able to produce at low cost, atmospheric pressure drying can be used. In this embodiment, atmospheric pressure means 0.1 MPa (atmospheric pressure).

[0137] An aerogel can be obtained by drying a washed and (if necessary) solvent-exchanged wet gel under atmospheric pressure at a temperature below the critical point of the solvent used for drying. The drying temperature varies depending on the type of the replaced solvent (or the solvent used for washing if no solvent exchange is performed). In view of the fact that drying at a particularly high temperature may accelerate the evaporation rate of the solvent and cause large cracks in the gel, the drying temperature can be set to 20 to 150 °C. Incidentally, the drying temperature may be 60 to 120 °C. Also, the drying time varies depending on the volume of the wet gel and the drying temperature, but it can be set to 4 to 120 hours. Incidentally, applying a pressure below the critical point to accelerate drying within a range that does not inhibit productivity is also included in atmospheric pressure drying.

[0138] An aerogel can also be obtained by subjecting a washed and (if necessary) solvent-exchanged wet gel to supercritical drying. Supercritical drying can be performed by a known method. Examples of the method of supercritical drying include a method of removing the solvent at a temperature and pressure above the critical point of the solvent contained in the wet gel. Alternatively, as a method of supercritical drying, the wet gel is immersed in liquefied carbon dioxide under conditions such as 20 to 25 °C and about 5 to 20 MPa to replace all or part of the solvent contained in the wet gel with carbon dioxide having a critical point lower than that of the solvent, and then carbon dioxide is removed alone or a mixture of carbon dioxide and the solvent is removed.

[0139] The aerogel obtained by such atmospheric pressure drying or supercritical drying may be further dried at 105 to 200 °C for about 0.5 to 2 hours under atmospheric pressure. This makes it easier to further obtain an aerogel having a low density and small pores. The additional drying may be performed at 150 to 200 °C under atmospheric pressure.

[0140] (Grinding process) When the wet gel pulverization process is not performed, aerogel particles are obtained by pulverizing the aerogel (aerogel block) obtained by drying. For example, it can be carried out by putting the aerogel into a jet mill, a roller mill, a bead mill, a hammer mill, etc. and operating at an appropriate rotation speed and time.

[0141] <Coating liquid> More specifically, the coating liquids shown below, namely the first to fourth coating liquids, can be mentioned as the coating liquid. Among the coating liquids, those with a high viscosity (for example, 1000 mPa·s or more) can be referred to as pastes.

[0142] (First coating liquid) The first coating liquid contains the above-mentioned aerogel particles with a specific surface area of 350 m 2 / g or less, a binder resin, and a liquid medium. It can also be said that the first coating liquid is a mixture of the above-mentioned aerogel particles, binder resin, and liquid medium.

[0143] In the first coating liquid, the specific surface area of the aerogel particles is 350 m 2 / g or less. Thereby, a coating liquid excellent in film-forming properties can be prepared. The reason for this is not necessarily clear, but the inventors speculate as follows. The specific surface area of the aerogel particles is considered to affect the adsorption force (adsorption amount) with respect to the binder resin. Therefore, when the specific surface area is too large, the binder resin is taken into the aerogel particles having a porous structure together with the liquid medium, and it is difficult to have an appropriate amount of the binder resin present on the surface of the aerogel particles in the state of the coating liquid. As a result, when the coating liquid is dried, the aerogel particles cannot be sufficiently bound by the binder resin, and a coating film having good film quality cannot be obtained. On the other hand, when the specific surface area of the aerogel particles is within the above range, an appropriate amount of the binder resin can be present on the surface of the aerogel particles, so it is considered possible to form a coating film in which the aerogel particles are preferably bound by the binder resin.

[0144] The binder resin has a function of binding aerogel particles to each other after the coating film is formed. Examples of the binder resin include epoxy resin, silicone resin, phenol resin, urea resin, melamine resin, polyurethane resin, polyethylene resin, polypropylene resin, polystyrene resin, polyester resin, acrylic resin (a polymer containing acrylic ester or methacrylic ester as a main structural unit), polyvinyl chloride resin, polyvinyl acetate resin, polyamide resin, polyimide resin, cellulose-based resin, polyvinyl-based resin, etc. Further, as the binder resin, an acrylic acid-based resin (a polymer containing acrylic acid, acrylate, methacrylic acid, or methacrylate as a structural unit), polyvinyl alcohol, polyethylene oxide, polyethylene glycol, etc. can also be used. Among these, from the viewpoints of heat resistance and toughness, silicone resin, acrylic resin, phenol resin, and polyester resin can be preferably used.

[0145] Examples of the cellulose-based resin include hydroxypropyl methylcellulose, carboxymethylcellulose ammonium, hydroxyethyl methylcellulose, etc. Examples of the polyvinyl-based resin include polyvinyl alcohol, polyvinyl pyrrolidone, etc.

[0146] Examples of the acrylic acid-based resin include polyacrylic acid, acrylic acid copolymer polymer, polyacrylate, acrylate copolymer polymer, etc.

[0147] When the binder resin is a thermosetting resin, the coating liquid may further contain a curing agent. The curing agent is not particularly limited and may be appropriately changed according to the type of the thermosetting resin. For example, when the thermosetting resin is an epoxy resin, a known epoxy resin curing agent can be used as the curing agent. Examples of the epoxy resin curing agent include amine-based curing agents, acid anhydride-based curing agents, polyamide-based curing agents, etc., and from the viewpoint of reactivity, amine-based curing agents and polyamide-based curing agents can be preferably used.

[0148] Examples of the liquid medium include water and organic solvents. The organic solvent is not particularly limited as long as it can disperse the aerogel particles. For example, aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p - cymene; aliphatic hydrocarbons such as hexane, heptane, and pentane; ethers such as diethyl ether, tetrahydrofuran, and 1,4 - dioxane; alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, and propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4 - hydroxy - 4 - methyl - 2 - pentanone; esters such as methyl acetate, ethyl acetate, and butyl acetate; amides such as N,N - dimethylformamide, N,N - dimethylacetamide, and N - methylpyrrolidone, etc. Among these, from the viewpoints of volatility, boiling point, etc., alcohols and ketones can be used, and particularly alcohols can be preferably used. Alcohols and ketones are suitable even when used in combination with those components because they are easily mixed with water, aqueous resins, etc.

[0149] The coating liquid may contain, as other components, a thickening agent, fibrous substances, pigments, leveling agents, film - forming aids, etc.

[0150] The thickening agent can improve the viscosity of the coating liquid and make the coating property on the object better. Examples of the thickening agent include fine particles such as organic polymers, fumed silica, layered inorganic additives, and clay minerals.

[0151] The fibrous substance can exhibit an anchoring function between aerogel particles after the formation of the coating film, and can further improve the coating film strength. The fibrous substance is not particularly limited, and examples include organic fibers and inorganic fibers. Examples of the organic fibers include polyamide-based fibers, polyimide-based fibers, polyvinyl alcohol-based fibers, polyvinylidene chloride-based fibers, polyvinyl chloride-based fibers, polyester-based fibers, polyacrylonitrile-based fibers, polyethylene-based fibers, polypropylene-based fibers, polyurethane-based fibers, phenol-based fibers, polyether ester-based fibers, polylactic acid-based fibers, polycarbonate-based fibers, and the like. Examples of the inorganic fibers include glass fibers, carbon fibers, ceramic fibers, metal fibers, and the like.

[0152] The content of the aerogel particles in the coating liquid can be 0.1 to 30% by mass from the viewpoints of dispersibility, filling amount of the aerogel particles, viscosity of the coating liquid, etc., but may also be 1 to 25% by mass. Further, from the viewpoint of being suitable for coating using a trowel or the like, the content of the aerogel particles in the coating liquid may be 2% by mass or more, and may also be 3% by mass or more.

[0153] The content of the binder resin in the coating liquid can be 1 to 40% by mass from the viewpoints of binding property between aerogel particles, heat insulation property of the coating film, etc., but may also be 1 to 30% by mass.

[0154] The content of the binder resin in the coating liquid can be, for example, 5 parts by mass or more with respect to 100 parts by mass of the aerogel particles, but may also be 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more. Thereby, the aerogel particles are easily and firmly bound by the binder resin, and the strength of the coating film is further improved.

[0155] Further, the content of the binder resin can be, for example, 150 parts by mass or less with respect to 100 parts by mass of the aerogel particles, but may also be 130 parts by mass or less, 100 parts by mass or less, or 90 parts by mass or less. Thereby, the ratio of the aerogel particles in the coating film becomes high, and the heat insulation property of the coating film is further improved.

[0156] The content of the fibrous substance in the coating liquid can be 1 to 50% by mass, but may also be 1 to 30% by mass, from the viewpoints of dispersibility in the coating liquid and manifestation of a good anchor function.

[0157] The content of the fibrous substance in the coating liquid can be, for example, 5 parts by mass or more with respect to 100 parts by mass of the aerogel particles, but may also be 7 parts by mass or more, or may also be 9 parts by mass or more. Thereby, the anchor effect by the fibrous substance is easily obtained, and the coating film strength is further improved.

[0158] Also, the content of the fibrous substance can be, for example, 50 parts by mass or less with respect to 100 parts by mass of the aerogel particles, but may also be 35 parts by mass or less, may also be 25 parts by mass or less, may also be 20 parts by mass or less, or may also be 15 parts by mass or less. Thereby, the ratio of the aerogel particles in the coating film becomes high, and the heat insulation property of the coating film is further improved.

[0159] The content of the thickener can be appropriately adjusted so as to obtain a desired coating liquid viscosity (for example, 1000 mPa·s or more). Since the viscosity of the coating liquid can also be improved by blending a binder resin, it is not always necessary to blend a thickener in that case.

[0160] (Second coating liquid) The second coating liquid contains aerogel particles, a binder resin, a fibrous substance having a fiber length of 1.5 mm or more, and a liquid medium. It can also be said that the second coating liquid is a mixture of the above-mentioned aerogel particles, binder resin, fibrous substance having a fiber length of 1.5 mm or more, and liquid medium. Hereinafter, the second coating liquid will be described, but the content overlapping with the description of the first coating liquid will be omitted as appropriate.

[0161] The second coating liquid contains fibrous substances having a fiber length of 1.5 mm or more. Thereby, while improving the coating film strength, the heat insulation property of the coating film can be ensured. Although the reason for this is not necessarily clear, the inventors speculate as follows. Generally, when producing a press-molded body such as that in Patent Document 2, for ensuring further strength of the molded body, it is preferable that the fibers are randomly oriented within the molded body. It is considered that short fibers are used in Patent Document 2 because short fibers are more likely to be randomly oriented than long fibers. However, when producing a thin film-like molded body, randomly orienting the fibers is likely to cause a heat path by the fibers in the thickness direction (the direction in which heat insulation is desired), leading to a loss of heat insulation property in the thickness direction. On the other hand, the coating liquid of the present embodiment contains long fibers. When forming a thin coating film on the target surface using the coating liquid, it is presumed that by deliberately using long fibers (fibrous substances having a fiber length of 1.5 mm or more), the fibers are likely to be oriented in the plane. It is considered that this makes it possible to improve the strength in the plane direction while maintaining high heat insulation property in the thickness direction.

[0162] From this perspective, the fiber length can be 2 mm or more, may be 2.5 mm or more, or may be 3 mm or more. On the other hand, the upper limit of the fiber length is not particularly limited, but from the perspective of dispersibility in the coating liquid, it can be 20 mm.

[0163] The fiber diameter of the fibrous substance can be 0.01 to 100 μm from the perspectives of dispersibility in the coating liquid, good anchor function, etc.

[0164] The content of the fibrous substance in the coating liquid is as described above. Also, based on the total mass of the fibrous substance, the content of the fibers having a fiber length of 1.5 mm or more can be 30% by mass or more, and may be 50% by mass or more. The upper limit of the content can be 100% by mass (that is, substantially the fiber length of all the fibrous substances in the coating liquid is 1.5 mm or more).

[0165] (The third coating liquid) The third coating liquid contains aerogel particles, a liquid medium, a first binder resin, and a second binder resin. It can also be said that the third coating liquid is a mixture of aerogel particles, a liquid medium, a first binder resin, and a second binder resin. Hereinafter, the third coating liquid will be described, and the contents overlapping with the descriptions of the first and second coating liquids will be omitted as appropriate.

[0166] The first binder resin and the second binder resin have a function of binding aerogel particles to each other after the formation of the coating film. Both the first binder resin and the second binder resin are dissolved in the liquid medium, and the solubility of the first binder resin in the liquid medium is higher than the solubility of the second binder resin in the liquid medium.

[0167] By including such first and second binder resins in the coating liquid, a coating film excellent in coating film strength and adhesiveness can be obtained. The reason for this is not necessarily clear, but the inventors speculate as follows. Since the solubility of the first binder resin and the second binder resin in the liquid medium is different, in the drying process (the process of removing the liquid medium) during the formation of the coating film, the second binder resin becomes saturated with respect to the liquid medium earlier than the first binder resin, and the second binder resin is more likely to precipitate first. Due to such a difference in solubility, a characteristic binder structure is formed during the formation of the coating film, and it is considered that excellent coating film strength and adhesiveness are obtained.

[0168] Although the above-mentioned characteristic binder structure is not necessarily clear, for example, it is speculated that the second binder resin binds to the aerogel particles (and the fibrous substance described later) first, and the first binder resin binds between the aerogel particles (or between the aerogel particles and the fibrous substance or between the fibrous substances) via the second binder resin, thereby obtaining excellent coating film strength and adhesiveness. It is also considered that the second binder resin becomes granular and fills between the aerogel particles, and then is bound by the first binder resin, so that the aerogel particles are firmly bound to each other.

[0169] Examples of the binder resin include the above resins. The first binder resin and the second binder resin may be selected from these, and more specifically, may be selected from the resins described later.

[0170] In the present embodiment, it is preferable that the content of the second binder resin is larger than the content of the first binder resin. Thereby, the above-described effects are more significantly exhibited. The content of the second binder resin is preferably more than 100 parts by mass with respect to 100 parts by mass of the first binder resin, more preferably 150 parts by mass or more, may be 200 parts by mass or more, may be 300 parts by mass or more, may be 400 parts by mass or more, or may be 600 parts by mass or more.

[0171] Also, from the viewpoint of excellent heat insulation performance, the content of the second binder resin may be 800 parts by mass or less, preferably 700 parts by mass or less, may be 600 parts by mass or less, may be 500 parts by mass or less, or may be 400 parts by mass or less with respect to 100 parts by mass of the first binder resin.

[0172] The total content of the first binder resin and the second binder resin in the coating liquid can be 1 to 40% by mass, but may be 1 to 30% by mass, from the viewpoints of the binding property between aerogel particles, the heat insulation property of the coating film, and the like.

[0173] The total content of the first binder resin and the second binder resin may be, for example, 5 parts by mass or more, preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and still more preferably 20 parts by mass or more with respect to 100 parts by mass of the aerogel particles. Thereby, the aerogel particles are more likely to be firmly bound by the binder resin, and the strength of the coating film is further improved.

[0174] Further, the total content of the first binder resin and the second binder resin may be, for example, 150 parts by mass or less, preferably 130 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 90 parts by mass or less with respect to 100 parts by mass of the aerogel particles. Thereby, the ratio of the aerogel particles in the coating film becomes high, and the heat insulation property of the coating film is further improved.

[0175] The first binder resin has a function of binding aerogel particles to each other after the formation of the coating film, and may be any resin that can be dissolved in a liquid medium. For example, when the liquid medium is an aqueous solvent, examples of the first binder resin include cellulose-based resins, polyvinyl alcohol, polyvinyl pyrrolidone, acrylic acid-based resins, polyethylene oxide, polyethylene glycol, and the like. Among these, from the viewpoint of excellent thickening property, cellulose-based resins, polyvinyl pyrrolidone, and acrylic acid-based resins can be preferably used.

[0176] The second binder resin may be any resin that can be dissolved in a liquid medium and has a lower solubility in the liquid medium than the first binder resin. The second binder resin may be a thermoplastic resin or a thermosetting resin.

[0177] Examples of the thermoplastic resin include acrylic resins, polyvinyl alcohol, polypropylene, polyvinyl chloride, and the like. Among these, from the viewpoint of handleability, acrylic resins and polyvinyl alcohol can be preferably used.

[0178] Examples of the thermosetting resin include epoxy resins, silicone resins, polyurethanes, and the like. Among these, from the viewpoint of excellent heat resistance, epoxy resins and silicone resins can be preferably used.

[0179] When the second binder resin is a thermosetting resin, the coating film may further contain a curing agent. The curing agent is not particularly limited and may be appropriately changed according to the type of the thermosetting resin. For example, when the thermosetting resin is an epoxy resin, a known epoxy resin curing agent can be used as the curing agent. Examples of the epoxy resin curing agent include amine-based curing agents, acid anhydride-based curing agents, polyamide-based curing agents, etc., and from the viewpoint of reactivity, amine-based and polyamide-based can be preferably used.

[0180] Examples of the liquid medium include the above-mentioned water and organic solvents. In a preferred embodiment, the liquid medium is preferably an aqueous solvent containing water. The aqueous solvent may be water or a mixed solvent containing water and an organic solvent. According to such a liquid medium, the dispersibility of the aerogel particles is improved, and a uniform coating film is easily obtained.

[0181] (Fourth coating liquid) The fourth coating liquid contains aerogel particles, a water-soluble polymer having a hydrophobic group, and a liquid medium. Since the dispersibility of the aerogel particles in the fourth coating liquid is improved by the water-soluble polymer having a hydrophobic group, the uneven distribution of the aerogel particles is small, and a coating film having sufficient film strength can be formed. Hereinafter, the fourth coating liquid will be described, and the contents overlapping with the descriptions of the first to third coating liquids will be omitted as appropriate.

[0182] The content of the aerogel particles in the fourth coating liquid may be, for example, 70% by volume or more, preferably 72% by volume or more, more preferably 74% by volume or more, based on the total volume of the solid content in the coating liquid. Also, the content of the aerogel particles in the fourth coating liquid may be, for example, 99% by volume or less, preferably 97% by volume or less, based on the total volume of the solid content in the fourth coating liquid.

[0183] <Water-soluble polymer> In the present embodiment, the water-soluble polymer may have a hydrophobic group and water solubility.

[0184] Examples of the hydrophobic group include an alkyl group (preferably a long-chain alkyl group having 6 to 26 carbon atoms), an ester group, an alkoxy group, a halogen, and the like. Among these, an alkyl group is preferable as the hydrophobic group, a long-chain alkyl group having 8 to 26 carbon atoms is more preferable, a long-chain alkyl group having 10 to 26 carbon atoms is still more preferable, a long-chain alkyl group having 12 to 26 carbon atoms is even more preferable, and a long-chain alkyl group having 15 to 26 carbon atoms may also be used.

[0185] Examples of the water-soluble polymer include a modified carboxyvinyl polymer, a modified polyether urethane, a cellulose-based resin, polyethylene oxide, polyvinyl alcohol, a polyacrylate, polyvinyl pyrrolidone, a dextrin-based resin, a chitin-based resin, a chitosan-based resin, and the like.

[0186] As the water-soluble polymer, a cellulose-based resin can be preferably used. Examples of the cellulose-based resin include methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and modified products (e.g., hydrophobized products) obtained by further modifying these.

[0187] As the cellulose-based resin, a cellulose-based resin having an alkyl group is preferable, and a cellulose-based resin having a long-chain alkyl group having 6 to 26 carbon atoms is more preferable. According to such a cellulose-based resin, the effects of the present invention can be more remarkably achieved. The number of carbon atoms of the long-chain alkyl group is preferably 8 to 26, more preferably 10 to 26, still more preferably 12 to 26, and even more preferably 15 to 26.

[0188] As the cellulose-based resin, for example, a cellulose-based resin having a structural unit represented by the following formula (A-1) is preferable.

[0189]

Chemical formula

[0190] In formula (A-1), R Ais a hydrogen atom, an alkyl group, a hydroxyalkyl group, -R A1 -O-R A2 represents a group (R A1 represents an alkanediyl group or a hydroxyalkanediyl group, and R A2 represents an alkyl group.). Three Rs A may be the same as or different from each other. However, among the three Rs A , at least one is an alkyl group or a group represented by -R A1 -O-R A2 .

[0191] In formula (A-1), as the alkyl group in R A , an alkyl group having 1 to 26 carbon atoms is preferred. Also, the alkyl group in R A is more preferably a short-chain alkyl group having 1 to 3 carbon atoms or a long-chain alkyl group having 6 to 26 carbon atoms. The number of carbon atoms of the long-chain alkyl group is preferably 8 to 26, more preferably 10 to 26, still more preferably 12 to 26, and even more preferably 15 to 26.

[0192] In formula (A-1), as the hydroxyalkyl group in R A , a hydroxyalkyl group having 1 to 26 carbon atoms is preferred, a hydroxyalkyl group having 1 to 10 carbon atoms is more preferred, and a hydroxyalkyl group having 1 to 5 carbon atoms is still more preferred.

[0193] In formula (A-1), the alkanediyl group in R A1 is preferably an alkanediyl group having 1 to 26 carbon atoms, more preferably an alkanediyl group having 1 to 10 carbon atoms, and still more preferably an alkanediyl group having 1 to 5 carbon atoms. Also, the hydroxyalkanediyl group in R A1 is preferably a hydroxyalkanediyl group having 1 to 26 carbon atoms, more preferably a hydroxyalkanediyl group having 1 to 10 carbon atoms, and still more preferably a hydroxyalkanediyl group having 1 to 5 carbon atoms.

[0194] In formula (A-1), R A2As for this, an alkyl group having 1 to 26 carbon atoms is preferable. Also, R A2 The alkyl group in is more preferably a short-chain alkyl group having 1 to 3 carbon atoms or a long-chain alkyl group having 6 to 26 carbon atoms, and more preferably a long-chain alkyl group. The number of carbon atoms of the long-chain alkyl group is preferably 8 to 26, more preferably 10 to 26, still more preferably 12 to 26, and even more preferably 15 to 26.

[0195] In formula (A-1), at least one of the three Rs A is a long-chain alkyl group, or at least one of the three Rs A is a group represented by -R A1 -O-R A2 and R A2 is preferably a long-chain alkyl group.

[0196] In the cellulose-based resin, the content of the long-chain alkyl group having 6 to 26 carbon atoms is preferably 0.01 to 5% by mass based on the total amount of the cellulose-based resin, and more preferably 0.01 to 3% by mass.

[0197] In the fourth coating liquid, the content of the water-soluble polymer may be, for example, 0.01% by volume or more based on the total volume of the solid content in the coating liquid, preferably 0.1% by volume or more, and more preferably 0.3% by volume or more. Also, the content of the water-soluble polymer may be, for example, 10% by volume or less based on the total volume of the solid content in the coating liquid, preferably 5% by volume or less, and more preferably 3% by volume or less.

[0198] <Liquid medium> In the fourth coating liquid, as the liquid medium, an aqueous solvent containing water is preferable. The aqueous solvent may contain an organic solvent in addition to water. The organic solvent may be any one having compatibility with water, and examples thereof include alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, and propylene glycol; ethers such as diethyl ether, tetrahydrofuran, and 1,4-dioxane; ketones such as acetone and methyl ethyl ketone; carboxylic acids such as acetic acid and propionic acid; and nitrogen-containing compounds such as acetonitrile, dimethylformamide, and triethylamine.

[0199] In the fourth coating liquid, the content of the liquid medium is not particularly limited and may be appropriately changed according to the desired viscosity of the coating liquid or the like. For example, the content of the liquid medium may be an amount such that the solid content concentration of the coating liquid falls within a suitable range described later.

[0200] The solid content concentration of the fourth coating liquid may be, for example, 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more. Also, the solid content concentration of the fourth coating liquid may be, for example, 70% by mass or less, preferably 60% by mass or less, more preferably 50% by mass or less.

[0201] <Other components> The fourth coating liquid may further contain components other than the aerogel particles, the water-soluble polymer, and the liquid medium.

[0202] The fourth coating liquid may further contain, for example, a binder resin. Examples of the binder resin include epoxy resins, silicone resins, phenolic resins, urea resins, melamine resins, polyurethane resins, polyethylene resins, polypropylene resins, polystyrene resins, polyester resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, polyamide resins, polyimide resins, polyvinyl-based resins, and the like. Among these, from the viewpoints of heat resistance and toughness, silicone resins, acrylic resins, phenolic resins, polyester resins, and the like can be preferably used.

[0203] When the fourth coating liquid contains a binder resin, the content of the binder resin may be, for example, 30% by volume or less, preferably 28% by volume or less, more preferably 25% by volume or less, based on the total volume of the solid content. Also, the content of the binder resin may be, for example, 0.1% by volume or more, and may be 1% by volume or more, based on the total volume of the solid content.

[0204] <Method for manufacturing a coating film and coating film> The method for manufacturing a coating film (coating film forming method) includes a step of removing a liquid medium from a coating liquid containing aerogel particles and a liquid medium. More specifically, the method for manufacturing a coating film can include a step of applying the above-described coating liquid onto an object and a step of removing the liquid medium from the coating liquid applied onto the object.

[0205] The method of applying the coating liquid onto the object is not particularly limited, and examples thereof include dip coating, spray coating, spin coating, roll coating, etc. When forming the coating film, the applied coating liquid may be left in an environment of 0 to 40°C, or the applied coating liquid may be subjected to heating (for example, 40 to 150°C) treatment, reduced pressure (for example, 10,000 Pa or less) treatment, or both of these treatments.

[0206] In addition, since the coating liquid of the present embodiment may have a high viscosity (paste-like), as shown in FIG. 1, a trowel (metal spatula) or the like can be used to apply the coating liquid onto the object. In FIG. 1, the coating liquid is applied to the bent portion of the pipe using a trowel. With the coating liquid of the present embodiment, a coating film having a thickness that is difficult to achieve with conventional heat insulating paints can be formed in a short time. Specifically, with such a coating liquid, a coating film having a thickness of at least about 2 mm can be formed by a single application, and extremely high working efficiency can be achieved as compared with conventional paints that could only obtain a coating film having a thickness of about 0.5 mm. In addition, since the coating liquid contains aerogel particles, a coating film having better heat insulating performance than conventional heat insulating paints can be obtained.

[0207] When the first coating liquid is used, thereby, the specific surface area is 350 m 2A first coating film containing aerogel particles and a binder resin (or a cured product thereof) with a content of less than 100 μm can be obtained. The first coating film can contain 40 to 95% by mass of aerogel particles and 1 to 50% by mass of the binder resin (or a cured product thereof).

[0208] When using the second coating liquid, a second coating film containing aerogel particles, a binder resin (or a cured product thereof), and a fibrous substance with a fiber length of 1.5 mm or more can be obtained. The second coating film can contain 40 to 95% by mass of aerogel particles, 1 to 40% by mass of the binder resin (or a cured product thereof), and 1 to 50% by mass of a fibrous substance with a fiber length of 1.5 mm or more.

[0209] When using the third coating liquid, a third coating film containing aerogel particles, a first binder resin, and a second binder resin (or a cured product thereof) can be obtained.

[0210] When using the fourth coating liquid, a fourth coating film containing aerogel particles and a water-soluble polymer having a hydrophobic group can be obtained.

[0211] The content of aerogel particles in the coating film can be, for example, 40% by mass or more, but may be 50% by mass or more, 60% by mass or more, or 70% by mass or more. Thereby, the heat insulation property of the coating film is further improved. Also, the content of aerogel particles in the coating film can be, for example, 95% by mass or less, but may be 90% by mass or less. Thereby, the coating film tends to be easily formed.

[0212] Particularly for the third coating film, the content of the first binder resin in the coating film can be, for example, 2 parts by mass or more, preferably 5 parts by mass or more, and more preferably 8 parts by mass or more with respect to 100 parts by mass of the aerogel particles. Also, the content of the first binder resin in the coating film can be, for example, 20 parts by mass or less, preferably 17 parts by mass or less, and more preferably 15 parts by mass or less with respect to 100 parts by mass of the aerogel particles.

[0213] Particularly for the third coating film, the content of the second binder resin (or its cured product) in the coating film may be, for example, 10 parts by mass or more, preferably 15 parts by mass or more, and may be 20 parts by mass or more with respect to 100 parts by mass of the aerogel particles. Also, the content of the second binder resin (or its cured product) in the coating film may be, for example, 100 parts by mass or less, preferably 80 parts by mass or less, may be 60 parts by mass or less, and may be 40 parts by mass or less with respect to 100 parts by mass of the aerogel particles.

[0214] The thickness of the coating film is not particularly limited and may be, for example, 0.01 to 30 mm, 0.1 to 20 mm, or 0.01 to 5 mm.

[0215] [Heat insulation material (2)]

[0216] The heat insulation material may be, for example, a heat insulation material (hereinafter, heat insulation material (2)) that satisfies the following formula (A). F1>F2 …(A) In the formula, F1 represents the adhesive strength of the heat insulation material after heating the heat insulation material at 220°C for 120 seconds, and F2 represents the adhesive strength of the heat insulation material after heating the heat insulation material at 260°C for 30 seconds.

[0217] F1 means the adhesive strength measured under the conditions of 90° peel and a tensile speed of 50 mm / min using a tensile testing machine (for example, "EZ Test EZ-S" manufactured by Shimadzu Corporation) for the heat insulation material in a state where the unheated heat insulation material is attached to a slide glass and allowed to stand for 15 minutes, and then cooled to 25°C after heating at 220°C for 120 seconds. F2 means the adhesive strength measured in the same manner as above for the heat insulation material in a state where the unheated heat insulation material is attached to a slide glass and allowed to stand for 15 minutes, and then cooled to 25°C after heating at 260°C for 30 seconds.

[0218] In formula (A), F1 and F2 can be regarded as corresponding to the adhesive force of the heat insulating material during and after the reflow process, respectively. That is, when the heat insulating material satisfies formula (A), during the reflow process, since the adhesive force of the heat insulating material is relatively large, the heat insulating material is likely to adhere to the first electronic component and / or the holding member, and the first electronic component can be more suitably protected from heat. After the reflow process, since the adhesive force of the heat insulating material is relatively small, the heat insulating material can be easily peeled off from the first electronic component and / or the holding member.

[0219] The heat insulating material (2) is preferably a heat insulating material that satisfies the following formula (B). F0≦F1 …(B) In the formula, F0 represents the adhesive force of the heat insulating material at 25°C, and F1 represents the adhesive force of the heat insulating material after heating the heat insulating material at 220°C for 120 seconds.

[0220] F0 means the adhesive force measured in the same manner as above after attaching the unheated heat insulating material to a slide glass at 25°C and leaving it standing for 15 minutes. Note that the fact that the heat insulating material has adhesiveness means that this F0 is 10 N / m or more.

[0221] In formula (B), F0 and F1 can be regarded as corresponding to the adhesive force of the heat insulating material before the reflow process (for example, the process of arranging the heat insulating material on the first electronic component and / or the holding member) and during the reflow process, respectively. That is, when the heat insulating material satisfies formula (B), before the reflow process, since the adhesive force of the heat insulating material is relatively small, the heat insulating material is easy to handle. During the reflow process, since the adhesive force of the heat insulating material is relatively large, the heat insulating material is likely to adhere to the first electronic component and / or the holding member, and the first electronic component can be more suitably protected from heat.

[0222] From the same perspective as described above, the heat insulating material (2) is more preferably a heat insulating material that satisfies both of the above formula (A) and formula (B).

[0223] The heat insulating material having the adhesive properties as described above contains, for example, a matrix polymer and hollow particles. The heat insulating material may be a cured product obtained by curing a heat insulating material precursor containing, for example, a monomer component constituting the monomer unit of the matrix polymer and hollow particles (polymerizing the monomers in the precursor).

[0224] In one embodiment, the heat insulating material (2) may be a heat insulating material pre-formed into a sheet shape (the heat insulating material precursor is pre-cured). In another embodiment, the heat insulating material (2) may be formed by disposing a liquid heat insulating material precursor on the first electronic component and / or the holding member and then curing the heat insulating material precursor.

[0225] From the viewpoint that the heat insulating material has low elasticity, excellent elongation, and can enhance the followability, the monomer component may contain a compound represented by the following formula (1).

Chemical formula

[0226] In one embodiment, one of R 11 and R 12 may be a hydrogen atom and the other may be a methyl group. In another embodiment, both of R 11 and R 12 may be hydrogen atoms. In other embodiments, both of R 11 and R 12 may be methyl groups.

[0227] In one embodiment, the polyoxyalkylene chain contains a structural unit represented by the following formula (2). Thereby, while suppressing an excessive increase in the viscosity of the heat insulating material precursor, the strength of the heat insulating material can be increased.

Chemical formula

[0228] In this case, R 13 may be a divalent group having a polyoxyethylene chain, and the compound represented by the formula (1) is preferably a compound represented by the following formula (1-2) (polyethylene glycol di(meth)acrylate).

Chemical formula

[0229] In another embodiment, the polyoxyalkylene chain contains a structural unit represented by the following formula (3). Thereby, the handling of the heat insulating material precursor can be facilitated.

Chemical formula

[0230] In this case, R 13 may be a divalent group having a polyoxypropylene chain, and the compound represented by the formula (1) is preferably a compound represented by the following formula (1-3) (polypropylene glycol di(meth)acrylate).

Chemical formula

[0231] In another embodiment, from the viewpoint of facilitating the balance between the strength of the heat insulating material of the compound represented by the formula (1) and the handleability of the heat insulating material precursor, the polyoxyalkylene chain is preferably a copolymer chain containing the structural unit represented by the above-described formula (2) and the structural unit represented by the formula (3). The copolymer chain may be any of an alternating copolymer chain, a block copolymer chain, or a random copolymer chain. The copolymer chain is preferably a random copolymer chain from the viewpoint of further lowering the crystallinity of the compound represented by the formula (1) and further facilitating the handling of the heat insulating material precursor.

[0232] In each of the above-described embodiments, in addition to the structural unit represented by the formula (2) and the structural unit represented by the formula (3), the polyoxyalkylene chain may have an oxyalkylene group having 4 to 5 carbon atoms, such as an oxytetramethylene group, an oxybutylene group, or an oxypentylene group, as a structural unit.

[0233] R 13 In addition to the above-described polyoxyalkylene chain, R may be a divalent group further having another organic group. The other organic group may be a chain-like group other than the polyoxyalkylene chain, and for example, may be a methylene chain (a chain having -CH2- as a structural unit), a polyester chain (a chain containing -COO- in the structural unit), a polyurethane chain (a chain containing -OCON- in the structural unit), or the like.

[0234] For example, the compound represented by the formula (1) may be a compound represented by the following formula (1-4).

Chemical formula

[0235] Multiple Rs 14 and R 15 may be identical to each other or may be different from each other. Multiple Rs 14 and R 15 preferably contain an ethylene group and a propylene group respectively. That is, the polyoxyalkylene chain represented by (R 14 O) k1 and the polyoxyalkylene chain represented by (R 15 O) k3 are preferably copolymer chains containing an oxyethylene group (structural unit represented by the above formula (2)) and an oxypropylene group (structural unit represented by the above formula (3)) respectively.

[0236] In each of the above-described embodiments, the number of oxyalkylene groups in the polyoxyalkylene chain is preferably 100 or more. When the number of oxyalkylene groups in the polyoxyalkylene chain is 100 or more, the main chain of the compound represented by formula (1) becomes longer, so that the elongation of the heat insulating material is further excellent and the strength of the heat insulating material can also be increased. The number of oxyalkylene groups corresponds to each of m in formula (1-2), n in formula (1-3), k1 and k3 in formula (1-4).

[0237] The number of oxyalkylene groups in the polyoxyalkylene chain is more preferably 130 or more, 180 or more, 200 or more, 220 or more, 250 or more, 270 or more, 300 or more, or 320 or more. The number of oxyalkylene groups in the polyoxyalkylene chain may be 600 or less, 570 or less, or 530 or less.

[0238] The weight average molecular weight of the compound represented by the formula (1) is preferably 5000 or more, 6000 or more, 7000 or more, 8000 or more, 9000 or more, 10000 or more, 11000 or more, 12000 or more, 13000 or more, 14000 or more, or 15000 or more from the viewpoint that the heat insulating material has lower elasticity and excellent elongation. The weight average molecular weight of the compound represented by the formula (1) is preferably 100000 or less, 80000 or less, 60000 or less, 34000 or less, 31000 or less, or 28000 or less from the viewpoint of facilitating the adjustment of the viscosity of the heat insulating material precursor.

[0239] The compound represented by the formula (1) may be liquid at 25°C. In this case, the viscosity of the compound represented by the formula (1) at 25°C is preferably 1000 Pa·s or less, 800 Pa·s or less, 600 Pa·s or less, 500 Pa·s or less, 350 Pa·s or less, 300 Pa·s or less, or 200 Pa·s or less from the viewpoints of facilitating the application to the application surface and enhancing the adhesion of the heat insulating material to the application surface. The viscosity of the compound represented by the formula (1) at 25°C may be 0.1 Pa·s or more, 0.2 Pa·s or more, 0.3 Pa·s or more, 1 Pa·s or more, 2 Pa·s or more, or 3 Pa·s or more.

[0240] The compound represented by the formula (1) may be solid at 25°C. In this case, from the viewpoint of further improving the handleability of the heat insulating material precursor, the compound represented by the formula (1) is preferably liquid at 50°C. Also, in this case, the viscosity of the compound represented by the formula (1) at 50°C is preferably 100 Pa·s or less, more preferably 50 Pa·s or less, still more preferably 30 Pa·s or less, and particularly preferably 20 Pa·s or less from the viewpoint of further improving the handleability of the heat insulating material precursor. The viscosity of the compound represented by the formula (1) at 50°C may be 0.1 Pa·s or more, 0.2 Pa·s or more, or 0.3 Pa·s or more.

[0241] Viscosity means the value measured based on JIS Z 8803, specifically, the value measured by an E-type viscometer (for example, PE-80L manufactured by Toki Sangyo Co., Ltd.). Note that the calibration of the viscometer can be performed based on JIS Z 8809-JS14000. The viscosity of the compound represented by formula (1) can be adjusted by adjusting the weight average molecular weight of the said compound.

[0242] From the viewpoint that the heat insulating material has lower elasticity and excellent elongation, the content of the compound represented by formula (1) is preferably 10% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more based on the total amount of the heat insulating material precursor. The content of the compound represented by formula (1) may be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less based on the total amount of the heat insulating material precursor.

[0243] From the viewpoint that the heat insulating material has lower elasticity and excellent elongation, the content of the compound represented by formula (1) is preferably 20 parts by mass or more, 30 parts by mass or more, or 40 parts by mass or more with respect to 100 parts by mass in total of the monomer components. The content of the compound represented by formula (1) may be 80 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less with respect to 100 parts by mass in total of the monomer components.

[0244] The monomer component may further contain other monomers copolymerizable with the compound represented by formula (1) above for the purpose of adjusting the physical properties of the heat insulating material precursor and the like.

[0245] The other monomer may be, for example, a compound having one (meth)acryloyl group. The compound may be, for example, an alkyl (meth)acrylate. Other monomers may be compounds having, in addition to one (meth)acryloyl group, an aromatic hydrocarbon group, a group containing a polyoxyalkylene chain, a group containing a heterocyclic ring, an alkoxy group, a phenoxy group, a group containing a silane group, a group containing a siloxane bond, a halogen atom, a hydroxyl group, a carboxyl group, an amino group, or an epoxy group. In particular, by containing an alkyl (meth)acrylate in the heat insulating material precursor, the viscosity of the heat insulating material precursor can be adjusted. Further, by containing a compound having a hydroxyl group, a carboxyl group, an amino group, or an epoxy group in addition to the (meth)acryloyl group in the heat insulating material precursor, the adhesion to the heat insulating material precursor and the members of the heat insulating material can be further improved.

[0246] The alkyl group (the alkyl group portion other than the (meth)acryloyl group) in the alkyl (meth)acrylate may be linear, branched, or alicyclic. The number of carbon atoms of the alkyl group may be, for example, 1 to 30. The number of carbon atoms of the alkyl group may be 1 to 11, 1 to 8, 1 to 6, or 1 to 4, or may be 12 to 30, 12 to 28, 12 to 24, 12 to 22, 12 to 18, or 12 to 14.

[0247] Examples of alkyl (meth) acrylates having a linear alkyl group include alkyl (meth) acrylates having a linear alkyl group with 1 to 11 carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, or undecyl (meth) acrylate; and alkyl (meth) acrylates having a linear alkyl group with 12 to 30 carbon atoms, such as dodecyl (meth) acrylate (lauryl (meth) acrylate), tetradecyl (meth) acrylate, hexadecyl (meth) acrylate (cetyl (meth) acrylate), octadecyl (meth) acrylate (stearyl (meth) acrylate), docosyl (meth) acrylate (behenyl (meth) acrylate), tetracosyl (meth) acrylate, hexacosyl (meth) acrylate, octacosyl (meth) acrylate.

[0248] Examples of alkyl (meth) acrylates having a branched alkyl group include alkyl (meth) acrylates having a branched alkyl group with 1 to 11 carbon atoms, such as s-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, isopentyl (meth) acrylate, isoamyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate; and alkyl (meth) acrylates having a branched alkyl group with 12 to 30 carbon atoms, such as isomyristyl (meth) acrylate, 2-propylheptyl (meth) acrylate, isoundecyl (meth) acrylate, isododecyl (meth) acrylate, isotridecyl (meth) acrylate, isopentadecyl (meth) acrylate, isohexadecyl (meth) acrylate, isoheptadecyl (meth) acrylate, isostearyl (meth) acrylate, decyltetradecanyl (meth) acrylate.

[0249] Examples of alkyl (meth)acrylates having an alicyclic alkyl group (cycloalkyl group) include cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, terpene (meth)acrylate, dicyclopentanyl (meth)acrylate, and the like.

[0250] Examples of compounds having a (meth)acryloyl group and an aromatic hydrocarbon group include benzyl (meth)acrylate and the like.

[0251] Examples of compounds having a (meth)acryloyl group and a group containing a polyoxyalkylene chain include polyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, polybutylene glycol (meth)acrylate, methoxypolybutylene glycol (meth)acrylate, and the like.

[0252] Examples of compounds having a (meth)acryloyl group and a group containing a heterocyclic ring include tetrahydrofurfuryl (meth)acrylate and the like.

[0253] Examples of compounds having a (meth)acryloyl group and an alkoxy group include 2-methoxyethyl acrylate and the like.

[0254] Examples of compounds having a (meth)acryloyl group and a phenoxy group include phenoxyethyl (meth)acrylate and the like.

[0255] Examples of compounds having a (meth)acryloyl group and a group containing a silane group include 3-acryloxypropyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.

[0256] Examples of the compound having a (meth)acryloyl group and a group containing a siloxane bond include silicone (meth)acrylate and the like.

[0257] Examples of the compound having a (meth)acryloyl group and a halogen atom include (meth)acrylates having a fluorine atom such as trifluoromethyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 1,1,1,3,3,3-hexafluoro-2-propyl (meth)acrylate, perfluoroethyl methyl (meth)acrylate, perfluoropropyl methyl (meth)acrylate, perfluorobutyl methyl (meth)acrylate, perfluoropentyl methyl (meth)acrylate, perfluorohexyl methyl (meth)acrylate, perfluoroheptyl methyl (meth)acrylate, perfluorooctyl methyl (meth)acrylate, perfluorononyl methyl (meth)acrylate, perfluorodecyl methyl (meth)acrylate, perfluoroundecyl methyl (meth)acrylate, perfluorododecyl methyl (meth)acrylate, perfluorotridecyl methyl (meth)acrylate, perfluorotetradecyl methyl (meth)acrylate, 2-(trifluoromethyl)ethyl (meth)acrylate, 2-(perfluoroethyl)ethyl (meth)acrylate, 2-(perfluoropropyl)ethyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluoropentyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluoroheptyl)ethyl (meth)acrylate, 2-(perfluorooctyl)ethyl (meth)acrylate, 2-(perfluorononyl)ethyl (meth)acrylate, 2-(perfluorotridecyl)ethyl (meth)acrylate, 2-(perfluorotetradecyl)ethyl (meth)acrylate, and the like.

[0258] Examples of the compound having a (meth)acryloyl group and a hydroxyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate; and hydroxyalkyl cycloalkane (meth)acrylates such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc.

[0259] Examples of the compound having a (meth)acryloyl group and a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, phthalic acid mono-hydroxyethyl acrylate (for example, "Aronix M5400" manufactured by Toagosei Co., Ltd.), and 2-acryloyloxyethyl succinate (for example, "NK Ester A-SA" manufactured by Shin-Nakamura Chemical Co., Ltd.), etc.

[0260] Examples of the compound having a (meth)acryloyl group and an amino group include, for example, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N,N-diethylaminopropyl (meth)acrylate, etc.

[0261] Examples of the compound having a (meth)acryloyl group and an epoxy group include glycidyl (meth)acrylate, glycidyl α-ethyl(meth)acrylate, glycidyl α-n-propyl(meth)acrylate, glycidyl α-n-butyl(meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 4,5-epoxypentyl (meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, 6,7-epoxyheptyl α-ethyl(meth)acrylate, 3-methyl-3,4-epoxybutyl (meth)acrylate, 4-methyl-4,5-epoxypentyl (meth)acrylate, 5-methyl-5,6-epoxyhexyl (meth)acrylate, β-methylglycidyl (meth)acrylate, β-methylglycidyl α-ethyl(meth)acrylate, and the like.

[0262] The monomer component may contain one kind or two or more kinds of the other monomers described above.

[0263] The content of the other monomer may be, for example, 1% by mass or more, 5% by mass or more, 10% by mass or more, 20% by mass or more, or 30% by mass or more, and may be 60% by mass or less, 50% by mass or less, or 40% by mass or less based on the total amount of the heat insulating material precursor.

[0264] The heat insulating material and the heat insulating material precursor include, as hollow particles, preferably thermally expandable hollow particles (hereinafter also referred to as "first hollow particles"). The first hollow particles have an outer shell and a hollow portion. The thermally expandable hollow particles in the present specification are hollow particles having a maximum volume expansion ratio of 10 times or more with respect to the volume at 25°C. When the first hollow particles are used, in the reflow process, the first hollow particles expand by heat, so that the adhesion area at the interface between the heat insulating material and the first electronic component and / or the holding member is reduced, and the heat insulating material can be easily removed after the reflow process.

[0265] The maximum volume expansion ratio of the first hollow particle is measured by thermomechanical analysis (TMA) as the ratio of the maximum volume of the first hollow particle to the volume at 25°C (maximum volume / volume at 25°C) when the temperature is raised at a rate of 10°C / min. The maximum volume expansion ratio of the first hollow particle may be, for example, 20 times or more, 30 times or more, or 40 times or more, and may be 120 times or less.

[0266] The outer shell is preferably composed of a thermoplastic polymer. In this case, since the outer shell becomes soft by heating, even if the liquid encapsulated in the hollow part vaporizes and the internal pressure increases, the hollow particle is less likely to crack and easily expands. The thermoplastic polymer may be, for example, a polymer containing acrylonitrile, vinylidene chloride, etc. as monomer units. The thickness of the outer shell may be 2 μm or more and may be 15 μm or less.

[0267] For example, a liquid is encapsulated in the hollow part of the first hollow particle. The first hollow particle is in such a state under normal temperature and pressure (for example, at least under atmospheric pressure and 30°C). The liquid is appropriately selected according to, for example, the heating temperature in the reflow process. The liquid is, for example, a liquid that vaporizes at a temperature below the maximum heating temperature in the reflow process. The liquid may be, for example, a hydrocarbon having a boiling point (under atmospheric pressure) of 50°C or more, 100°C or more, 150°C or more, or 200°C or more. In addition to the above liquid, a gas may be further encapsulated in the hollow part of the first hollow particle.

[0268] Examples of the components encapsulated in the hollow part of the first hollow particle include hydrocarbons such as propane, propylene, butene, normal butane, isobutane, normal pentane, isopentane, neopentane, normal hexane, isohexane, heptane, isooctane, normal octane, isoalkane (carbon number: 10 - 13), petroleum ether; low-boiling compounds such as halides of methane, tetraalkylsilane; compounds that gasify by thermal decomposition such as azodicarboxamide.

[0269] The average particle diameter of the first hollow particles may be 5 μm or more, 10 μm or more, or 20 μm or more, and may be 50 μm or less, 40 μm or less, or 30 μm or less. The average particle diameter of the first hollow particles is measured by the laser diffraction / scattering method (for example, using "SALD-7500nano" manufactured by Shimadzu Corporation).

[0270] From the viewpoint that the composition is more preferably used as a heat insulating material in the reflow process (generally heated up to 260 °C), the expansion start temperature of the first hollow particles is preferably 70 °C or more, 100 °C or more, 130 °C or more, or 160 °C or more, and preferably 260 °C or less. The expansion start temperature of the first hollow particles means, in the profile of temperature (horizontal axis) - volume change (vertical axis) when the temperature is raised at a rate of 10 °C / min by thermomechanical analysis (TMA), the temperature at the intersection of the tangent line at the point where a volume change of 3 times or more / 5 °C occurs and the straight line (horizontal axis) with a volume change of zero (initial volume).

[0271] The maximum expansion temperature of the first hollow particles is preferably 100 °C or more, 150 °C or more, 200 °C or more, or 220 °C or more, and preferably 290 °C or less, 280 °C or less, or 270 °C or less. The maximum expansion temperature of the first hollow particles means the temperature when the first hollow particles exhibit the above-described maximum volume expansion ratio.

[0272] From the viewpoint that peeling in the peeling process becomes easier, the content of the first hollow particles is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 8% by mass or more, and may be 20% by mass or less, or 15% by mass or less, based on the total mass of the heat insulating material (heat insulating material precursor).

[0273] From the viewpoint that peeling in the peeling process becomes easier, the content of the first hollow particles is preferably 1% by volume or more, more preferably 2% by volume or more, still more preferably 3% by volume or more, particularly preferably 4% by volume or more, and may be, for example, 10% by volume or less, 7% by volume or less, or 5% by volume or less, based on the total volume of the heat insulating material (heat insulating material precursor).

[0274] The heat insulating material (heat insulating material precursor) may further contain hollow particles other than the first hollow particles (hereinafter also referred to as "second hollow particles") from the viewpoint of further improving heat insulation performance. The second hollow particles have an outer shell and a hollow portion. That is, the second hollow particles are hollow particles having a maximum volume expansion ratio of less than 10 times with respect to the volume at 25°C. The maximum volume expansion ratio of the second hollow particles is measured in the same manner as that of the first hollow particles.

[0275] The outer shell is preferably composed of a thermoplastic polymer. In this case, the hollow particles are less likely to crack even when pressurized, can maintain the hollow structure, and can maintain heat insulation performance. The thermoplastic polymer may be, for example, a polymer containing acrylonitrile, vinylidene chloride, etc. as monomer units. The thickness of the outer shell may be 0.005 μm or more and may be 15 μm or less.

[0276] For example, a gas is encapsulated in the hollow portion of the second hollow particles. The second hollow particles are in such a state under normal temperature and pressure (for example, at least under atmospheric pressure and 30°C). In addition to the gas, a liquid may be further encapsulated in the hollow portion of the second hollow particles.

[0277] Examples of the components encapsulated in the hollow portion of the second hollow particles include hydrocarbons such as propane, propylene, butene, normal butane, isobutane, normal pentane, isopentane, neopentane, normal hexane, isohexane, heptane, isooctane, normal octane, isoalkane (carbon number: 10 - 13), petroleum ether; low-boiling compounds such as halogenated methane and tetraalkylsilane; decomposition products of compounds that gasify by thermal decomposition such as azodicarbonamide.

[0278] From the perspective of enhancing heat insulation performance, the average particle diameter of the second hollow particles is preferably 150 μm or less, more preferably 120 μm or less, still more preferably 100 μm or less, and may be, for example, 10 μm or more, 20 μm or more, or 30 μm or more. The average particle diameter of the second hollow particles is measured by the laser diffraction / scattering method (for example, using "SALD-7500nano" manufactured by Shimadzu Corporation).

[0279] The density of the second hollow particles is preferably 50 kg / m 3 or less, or may be 40 kg / m 3 or less, and may be 10 kg / m 3 or more, or 20 kg / m 3 or more. The density of the second hollow particles in this specification means the density measured by the tap density method. That is, the second hollow particles (about 5 g) are put into a 10 mL graduated cylinder, tapped 50 times, and the volume when the top surface becomes stable is taken as the stable volume, and the density is obtained by the following formula. Density = initial input amount (kg) / stable volume (m 3 )

[0280] From the perspective of further enhancing heat insulation performance, the content of the second hollow particles is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and may be, for example, 20% by mass or less, based on the total mass of the heat insulating material (heat insulating material precursor).

[0281] From the perspective of further enhancing heat insulation performance, the content of the second hollow particles is preferably 50% by volume or more, more preferably 60% by volume or more, and may be, for example, 95% by volume or less, based on the total volume of the heat insulating material (heat insulating material precursor).

[0282] The total content of the hollow particles (the content including the first hollow particles and the second hollow particles) may be, for example, 5% by mass or more, 10% by mass or more, or 15% by mass or more, and may be 40% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total amount of the heat insulating material (heat insulating material precursor).

[0283] The total content of the hollow particles (the content including the first hollow particles and the second hollow particles) may be, for example, 50% by volume or more, 60% by volume or more, or 70% by volume or more, and may be 95% by volume or less, based on the total volume of the heat insulating material (heat insulating material precursor).

[0284] The heat insulating material precursor may further contain a polymerization initiator. The polymerization initiator may be, for example, a thermal polymerization initiator that generates radicals by heat, a photopolymerization initiator that generates radicals by light, etc. The polymerization initiator is preferably a thermal polymerization initiator.

[0285] When the heat insulating material precursor contains a thermal polymerization initiator, by applying heat to the heat insulating material precursor, the precursor can be cured to obtain a heat insulating material. In this case, the heat insulating material precursor may preferably be a heat insulating material precursor that is cured by heating at 105°C or higher, more preferably 110°C or higher, still more preferably 115°C or higher, and may be, for example, a heat insulating material precursor that is cured by heating at 200°C or lower, 190°C or lower, or 180°C or lower. The heating time when heating the heat insulating material precursor may be appropriately selected according to the composition of the heat insulating material precursor so that the heat insulating material precursor is preferably cured.

[0286] Examples of the thermal polymerization initiator include azo compounds such as azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitrile, and azodibenzoyl, and organic peroxides such as benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, di-t-butyl peroxyhexahydroterephthalate, t-butyl peroxy-2-ethylhexanoate, 1,1-t-butyl peroxy-3,3,5-trimethylcyclohexane, and t-butyl peroxyisopropyl carbonate. The thermal polymerization initiator may be used alone or in combination of two or more thereof.

[0287] When the heat insulating material precursor contains a photoinitiator, for example, by irradiating the heat insulating material precursor with light (for example, light (ultraviolet light) including at least a part of wavelengths of 200 to 400 nm), the precursor can be cured to obtain a heat insulating material. The conditions for light irradiation may be appropriately set according to the type of photoinitiator.

[0288] The photoinitiator may be, for example, a benzoin ether-based photoinitiator, an acetophenone-based photoinitiator, an α-ketol-based photoinitiator, an aromatic sulfonyl chloride-based photoinitiator, a photoactive oxime-based photoinitiator, a benzoin-based photoinitiator, a benzyl-based photoinitiator, a benzophenone-based photoinitiator, a ketal-based photoinitiator, a thioxanthone-based photoinitiator, an acylphosphine oxide-based photoinitiator, etc.

[0289] Examples of the benzoin ether-based photoinitiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one (for example, "Irgacure 651" manufactured by BASF), anisole methyl ether, etc. Examples of the acetophenone-based photoinitiator include 1-hydroxycyclohexyl phenyl ketone (for example, "Irgacure 184" manufactured by BASF), 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (for example, "Irgacure 2959" manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (for example, "Irgacure 1173" manufactured by BASF), methoxyacetophenone, etc.

[0290] Examples of α-ketol-based photoinitiators include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)-phenyl]-2-hydroxy-2-methylpropan-1-one, etc. Examples of aromatic sulfonyl chloride-based photoinitiators include 2-naphthalenesulfonyl chloride, etc. Examples of photoactive oxime-based photoinitiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime, etc.

[0291] Examples of benzoin-based photoinitiators include benzoin, etc. Examples of benzyl-based photoinitiators include benzyl, etc. Examples of benzophenone-based photoinitiators include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, etc. Examples of ketal-based photoinitiators include benzyldimethyl ketal, etc. Examples of thioxanthone-based photoinitiators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, etc.

[0292] Examples of acylphosphine-based photoinitiators include bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-n-butylphosphine oxide, bis(2,6-dimethoxybenzoyl)-(2-methylpropan-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-(1-methylpropan-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-t-butylphosphine oxide, bis(2,6-dimethoxybenzoyl)cyclohexylphosphine oxide, bis(2,6-dimethoxybenzoyl)octylphosphine oxide, bis(2-methoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2-methoxybenzoyl)(1-methylpropan-1-yl)phosphine oxide, bis(2,6-diethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,6-diethoxybenzoyl)(1-methylpropan-1-yl)phosphine oxide, bis(2,6-dibutoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4-dimethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)(2,4-dipentoxyphenyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)benzylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylpropylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoylbenzyloctylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diethylphenylphosphine oxide, bis(2,4,(6-trimethylbenzoyl)-2,3,5,6-tetramethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)isobutylphosphine oxide, 2,6-dimethoxybenzoyl-2,4,6-trimethylbenzoyl-n-butylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-dibutoxyphenylphosphine oxide, 1,10-bis[bis(2,4,6-trimethylbenzoyl)phosphine oxide]decane, tri(2-methylbenzoyl)phosphine oxide, and the like can be mentioned.,

[0293] The above-mentioned photoinitiators may be used alone or in combination of two or more kinds.,

[0294] From the viewpoint of allowing the polymerization to proceed suitably, the content of the polymerization initiator is preferably 0.01 part by mass or more, more preferably 0.02 part by mass or more, still more preferably 0.05 part by mass or more, with respect to 100 parts by mass in total of the monomer components. From the viewpoint of making the molecular weight of the polymer in the heat insulating material fall within a suitable range and suppressing decomposition products, the content of the polymerization initiator is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, and particularly preferably 1 part by mass or less, with respect to 100 parts by mass in total of the monomer components.,

[0295] The heat insulating material and the heat insulating material precursor can contain a plasticizer as an additive. By using the plasticizer, the adhesiveness of the heat insulating material precursor and the elongation of the heat insulating material can be further enhanced., Examples of the plasticizer include tackifiers such as butadiene rubber, isoprene rubber, silicone rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, ethylene-propylene rubber, urethane rubber, acrylic resin, rosin resin, terpene resin, or polyalkylene glycol. The content of the plasticizer may be 0.1 part by mass or more, 1 part by mass or more, or 3 part by mass or more, and may be 20 parts by mass or less, 15 parts by mass or less, 12 parts by mass or less, or 10 parts by mass or less with respect to 100 parts by mass in total of the monomer components.

[0296] The heat insulating material and the heat insulating material precursor may further contain other additives as necessary. Examples of the other additives include antioxidants, surface treatment agents (e.g., silane coupling agents), dispersants, colorants, crystal nucleating agents, heat stabilizers, foaming agents, flame retardants, vibration damping agents, dehydrating agents, flame retardant aids (e.g., metal oxides), and the like. The content of the other additives may be 0.1% by mass or more and may be 30% by mass or less based on the total amount of the heat insulating material (heat insulating material precursor).

[0297] The heat insulating material precursor is preferably liquid at 25°C. Thereby, it can be suitably applied to the surface of the first electronic component and / or the holding member, and the adhesion to the application surface can also be enhanced. The heat insulating material precursor may be solid at 25°C, and in that case, it is preferably liquefied by heating (e.g., at 50°C or higher). The heat insulating material precursor may be applied in a liquid state and then cured, whereby it is possible to suppress the heat insulating material precursor from causing dripping and pump-out phenomena.

[0298] [Heat Insulating Material (3)] The heat insulating material may be, for example, a heat insulating material (hereinafter, heat insulating material (3)) containing first hollow particles that are thermally expandable hollow particles, second hollow particles that are hollow particles other than the first hollow particles, and a matrix polymer.

[0299] The heat insulating material (3) may be, for example, a cured product of a composition containing first hollow particles, second hollow particles, and a polymerizable compound.

[0300] The heat insulating material (3) may be in the form of a sheet.

[0301] The types and contents of the first and second hollow particles contained in the heat insulating material (3) may be the same as those of the first and second hollow particles contained in the composition or composition set described later. Regarding the content, “based on the total mass of the composition” shall be read as “based on the total mass of the heat insulating material (3)”, and “based on the total volume of the composition” shall be read as “based on the total volume of the heat insulating material (3)”.

[0302] The matrix polymer contained in the heat insulating material (3) is a polymer (binder polymer) that serves as a matrix (forms a continuous phase) for holding other materials contained in the heat insulating material (3). The matrix polymer is a polymer of the polymerizable compound contained in the composition or composition set described later.

[0303] The content of the matrix polymer may be, for example, 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more, and may be 95% by mass or less, or 90% by mass or less, based on the total mass of the heat insulating material (3).

[0304] When the heat insulating material (3) is a sheet, the thickness of the sheet is not particularly limited and may be, for example, 200 μm or more and 2000 μm or less.

[0305] The heat insulating material (3) may further contain an additive that the composition or composition set described later may contain. In that case, the content of the additive contained in the sheet may be the same as the content of the additive contained in the composition or composition set described later (the reading of the content is the same as described above).

[0306] The composition is a composition containing a first hollow particle, a second hollow particle, and a polymerizable compound.

[0307] (First hollow particle) The first hollow particle has an outer shell and a hollow portion. The first hollow particle is a hollow particle that expands by heat (thermally expandable). The thermally expandable hollow particle in this specification is a hollow particle having a maximum volume expansion ratio of 10 times or more with respect to the volume at 25°C. When the first hollow particle is used, in the reflow process, as the first hollow particle expands by heat, the adhesion area at the interface between the heat insulating material and the device decreases, and the heat insulating material (3) can be easily removed after the reflow process.

[0308] The maximum volume expansion ratio of the first hollow particle is measured by thermomechanical analysis (TMA) as the ratio of the maximum volume of the first hollow particle to the volume at 25°C (maximum volume / volume at 25°C) when the temperature is raised at a rate of 10°C / min. The maximum volume expansion ratio of the first hollow particle may be, for example, 20 times or more, 30 times or more, or 40 times or more, and may be 120 times or less.

[0309] The outer shell is preferably composed of a thermoplastic polymer. In this case, since the outer shell becomes soft by heating, even if the liquid enclosed in the hollow portion vaporizes and the internal pressure rises, the hollow particle is less likely to crack and expands easily. The thermoplastic polymer may be, for example, a polymer containing acrylonitrile, vinylidene chloride, etc. as monomer units. The thickness of the outer shell may be 2 μm or more and may be 15 μm or less.

[0310] For example, a liquid is enclosed in the hollow portion of the first hollow particle. The first hollow particle is in such a state under normal temperature and pressure (for example, at least under atmospheric pressure and 30°C). The liquid is appropriately selected according to, for example, the heating temperature in the reflow process. The liquid is, for example, a liquid that vaporizes at a temperature below the maximum heating temperature in the reflow process. The liquid may be, for example, a hydrocarbon having a boiling point (under atmospheric pressure) of 50°C or more, 100°C or more, 150°C or more, or 200°C or more. In addition to the above liquid, a gas may be further enclosed in the hollow portion of the first hollow particle.

[0311] Examples of the components encapsulated in the hollow portion of the first hollow particles include hydrocarbons such as propane, propylene, butene, normal butane, isobutane, normal pentane, isopentane, neopentane, normal hexane, isohexane, heptane, isooctane, normal octane, isoalkane (carbon number: 10 to 13), and petroleum ether; low-boiling compounds such as methane halides and tetraalkylsilane; and compounds that gasify by thermal decomposition such as azodicarboxamide.

[0312] The average particle diameter of the first hollow particles may be 5 μm or more, 10 μm or more, or 20 μm or more, and may be 50 μm or less, 40 μm or less, or 30 μm or less. The average particle diameter of the first hollow particles is measured by the laser diffraction / scattering method (for example, using "SALD-7500nano" manufactured by Shimadzu Corporation).

[0313] From the viewpoint of being more preferably used as a heat insulating material in the reflow process (generally heated up to 260 °C), the expansion start temperature of the first hollow particles is preferably 70 °C or more, 100 °C or more, 130 °C or more, or 160 °C or more, and preferably 260 °C or less. The expansion start temperature of the first hollow particles means the temperature at the intersection of the tangent line of the profile of temperature (horizontal axis) - volume change (vertical axis) when the temperature is raised at a rate of 10 °C / min in a thermomechanical analysis (TMA) and the straight line (horizontal axis) with a volume change of zero (initial volume) at the point where a volume change of 3 times or more / 5 °C occurs.

[0314] From the viewpoint of being more preferably used as a heat insulating material in the reflow process, the maximum expansion temperature of the first hollow particles is preferably 100 °C or more, 150 °C or more, 200 °C or more, or 220 °C or more, and preferably 290 °C or less, 280 °C or less, or 270 °C or less. The maximum expansion temperature of the first hollow particles means the temperature when the first hollow particles exhibit the maximum volume expansion ratio described above.

[0315] From the viewpoint of facilitating the removal of the heat insulating material (3) after the reflow process, the content of the first hollow particles is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 8% by mass or more, based on the total mass of the composition, and may be 20% by mass or less, or 15% by mass or less.

[0316] From the viewpoint of facilitating the removal of the heat insulating material (3) after the reflow process, the content of the first hollow particles is preferably 1% by volume or more, more preferably 2% by volume or more, still more preferably 3% by volume or more, particularly preferably 4% by volume or more, based on the volume of the composition, and may be, for example, 10% by volume or less, 7% by volume or less, or 5% by volume or less.

[0317] (Second hollow particles) The second hollow particles have an outer shell and a hollow portion. The second hollow particles are hollow particles other than the first hollow particles. That is, the second hollow particles are hollow particles having a maximum volume expansion ratio of less than 10 times with respect to the volume at 25°C. By using the second hollow particles, the heat insulation property of the heat insulating material (3) is further improved. The maximum volume expansion ratio of the second hollow particles is measured in the same manner as that of the first hollow particles.

[0318] The outer shell is preferably composed of a thermoplastic polymer. In this case, the hollow particles are less likely to crack even when pressurized, can maintain the hollow structure, and can maintain the heat insulation property. The thermoplastic polymer may be, for example, a polymer containing acrylonitrile, vinylidene chloride, etc. as monomer units. The thickness of the outer shell may be 0.005 μm or more and may be 15 μm or less.

[0319] For example, a gas is encapsulated in the hollow portion of the second hollow particles. The second hollow particles are in such a state under normal temperature and pressure (for example, at least under atmospheric pressure and 30°C). In addition to the gas, a liquid may be further encapsulated in the hollow portion of the second hollow particles.

[0320] Examples of the component encapsulated in the hollow portion of the second hollow particle include hydrocarbons such as propane, propylene, butene, normal butane, isobutane, normal pentane, isopentane, neopentane, normal hexane, isohexane, heptane, isooctane, normal octane, isoalkane (carbon number: 10 to 13), and petroleum ether; low-boiling compounds such as methane halide and tetraalkylsilane; and decomposition products of compounds that gasify by thermal decomposition such as azodicarboxamide.

[0321] From the viewpoint of enhancing heat insulation performance, the average particle diameter of the second hollow particle is preferably 150 μm or less, more preferably 120 μm or less, still more preferably 100 μm or less, and may be, for example, 10 μm or more, 20 μm or more, or 30 μm or more. The average particle diameter of the second hollow particle is measured by the laser diffraction / scattering method (for example, using "SALD-7500nano" manufactured by Shimadzu Corporation).

[0322] The density of the second hollow particle may be 50 kg / m 3 or less, or 40 kg / m 3 or less, and may be 10 kg / m 3 or more, or 20 kg / m 3 or more. The density of the second hollow particle in this specification means the density measured by the tap density method. That is, the second hollow particle (about 5 g) is put into a 10 mL graduated cylinder, tapped 50 times, and the volume when the top surface becomes stable is defined as the stable volume, and the density is obtained by the following formula. Density = initial input amount (kg) / stable volume (m 3 )

[0323] From the viewpoint of enhancing the heat insulation performance of the heat insulating material (3), the content of the second hollow particle is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and may be, for example, 20% by mass or less, based on the total mass of the composition.

[0324] From the viewpoint of enhancing the heat insulation property of the heat insulating material (3), the content of the second hollow particles is preferably 50% by volume or more, more preferably 60% by volume or more, and may be, for example, 95% by volume or less, based on the total volume of the composition.

[0325] The total content of the hollow particles (the content including the first hollow particles and the second hollow particles) may be, for example, 5% by mass or more, 10% by mass or more, or 15% by mass or more, and may be 40% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total mass of the composition.

[0326] The total content of the hollow particles (the content including the first hollow particles and the second hollow particles) may be, for example, 50% by volume or more, 60% by volume or more, or 70% by volume or more, and may be 95% by volume or less, based on the total volume of the composition.

[0327] (Polymerizable compound) The polymerizable compound is not particularly limited, and may include, for example, a compound represented by the following formula (1).

Chemical formula

[0328] When the polymerizable compound is a compound represented by the above formula (1), the cured product of the composition has low elasticity and excellent elongation, and can enhance the followability to the adherend.

[0329] In one embodiment, one of R 11 and R 12 may be a hydrogen atom and the other may be a methyl group. In another embodiment, both of R 11 and R 12 may be hydrogen atoms. In another embodiment, both of R 11 and R 12 may be methyl groups.

[0330] In one embodiment, the polyoxyalkylene chain contains a structural unit represented by the following formula (2). Thereby, while suppressing an excessive increase in the viscosity of the composition, the strength of the cured product can be increased.

Chemical formula

[0331] In this case, R 13 may be a divalent group having a polyoxyethylene chain, and the compound represented by the formula (1) is preferably a compound represented by the following formula (1-2) (polyethylene glycol di(meth)acrylate).

Chemical formula

[0332] In another embodiment, the polyoxyalkylene chain contains a structural unit represented by the following formula (3). Thereby, the handling of the composition can be facilitated.

Chemical formula

[0333] In this case, R 13 may be a divalent group having a polyoxypropylene chain, and the compound represented by the formula (1) is preferably a compound represented by the following formula (1-3) (polypropylene glycol di(meth)acrylate).

Chemical formula

[0334] In another embodiment, from the viewpoint of facilitating both the strength of the cured product of the compound represented by the formula (1) and the handleability of the composition, the polyoxyalkylene chain is preferably a copolymer chain containing the structural unit represented by the above-described formula (2) and the structural unit represented by the formula (3). The copolymer chain may be any of an alternating copolymer chain, a block copolymer chain, or a random copolymer chain. The copolymer chain is preferably a random copolymer chain from the viewpoint of further lowering the crystallinity of the compound represented by the formula (1) and further facilitating the handling of the composition.

[0335] In each of the above-described embodiments, in addition to the structural unit represented by the formula (2) and the structural unit represented by the formula (3), the polyoxyalkylene chain may have an oxyalkylene group having 4 to 5 carbon atoms, such as an oxytetramethylene group, an oxybutylene group, or an oxypentylene group, as a structural unit.

[0336] R 13 In addition to the above-described polyoxyalkylene chain, may be a divalent group further having another organic group. The other organic group may be a chain-like group other than the polyoxyalkylene chain, and may be, for example, a methylene chain (a chain having -CH2- as a structural unit), a polyester chain (a chain containing -COO- in the structural unit), a polyurethane chain (a chain containing -OCON- in the structural unit), or the like.

[0337] For example, the compound represented by the formula (1) may be a compound represented by the following formula (1-4).

Chemical formula

[0338] A plurality of R 14 and R 15 may each be the same as or different from each other. A plurality of R 14 and R 15 each preferably contain an ethylene group and a propylene group. That is, the polyoxyalkylene chain represented by (R 14 O) k1 and the polyoxyalkylene chain represented by (R 15 O) k3 are each preferably a copolymer chain containing an oxyethylene group (structural unit represented by the above formula (2)) and an oxypropylene group (structural unit represented by the above formula (3)).

[0339] In each of the above-described embodiments, the number of oxyalkylene groups in the polyoxyalkylene chain is preferably 100 or more. When the number of oxyalkylene groups in the polyoxyalkylene chain is 100 or more, the main chain of the compound represented by the formula (1) becomes longer, so that the elongation of the cured product is further excellent and the strength of the cured product can also be increased. The number of oxyalkylene groups corresponds to each of m in the formula (1-2), n in the formula (1-3), k1, and k3 in the formula (1-4).

[0340] The number of oxyalkylene groups in the polyoxyalkylene chain is more preferably 130 or more, 180 or more, 200 or more, 220 or more, 250 or more, 270 or more, 300 or more, or 320 or more. The number of oxyalkylene groups in the polyoxyalkylene chain may be 600 or less, 570 or less, or 530 or less.

[0341] The weight-average molecular weight of the compound represented by the formula (1) is preferably 5000 or more, 6000 or more, 7000 or more, 8000 or more, 9000 or more, 10000 or more, 11000 or more, 12000 or more, 13000 or more, 14000 or more, or 15000 or more from the viewpoint that the cured product has lower elasticity and excellent elongation. The weight-average molecular weight of the compound represented by the formula (1) is preferably 100000 or less, 80000 or less, 60000 or less, 34000 or less, 31000 or less, or 28000 or less from the viewpoint of facilitating the adjustment of the viscosity of the composition.

[0342] The compound represented by the formula (1) may be liquid at 25°C. In this case, the viscosity of the compound represented by the formula (1) at 25°C is preferably 1000 Pa·s or less, 800 Pa·s or less, 600 Pa·s or less, 500 Pa·s or less, 350 Pa·s or less, 300 Pa·s or less, or 200 Pa·s or less from the viewpoints of facilitating application to the application surface and enhancing the adhesion of the cured product to the application surface. The viscosity of the compound represented by the formula (1) at 25°C may be 0.1 Pa·s or more, 0.2 Pa·s or more, 0.3 Pa·s or more, 1 Pa·s or more, 2 Pa·s or more, or 3 Pa·s or more.

[0343] The compound represented by the formula (1) may be solid at 25°C. In this case, from the viewpoint of further improving the handleability of the composition, the compound represented by the formula (1) is preferably liquid at 50°C. Also, in this case, the viscosity of the compound represented by the formula (1) at 50°C is preferably 100 Pa·s or less, more preferably 50 Pa·s or less, still more preferably 30 Pa·s or less, and particularly preferably 20 Pa·s or less from the viewpoint of further improving the handleability of the composition. The viscosity of the compound represented by the formula (1) at 50°C may be 0.1 Pa·s or more, 0.2 Pa·s or more, or 0.3 Pa·s or more.

[0344] The viscosity means the value measured based on JIS Z 8803, specifically, the value measured by an E-type viscometer (for example, PE-80L manufactured by Toki Sangyo Co., Ltd.). The calibration of the viscometer can be carried out based on JIS Z 8809-JS14000. The viscosity of the compound represented by formula (1) can be adjusted by adjusting the weight average molecular weight of the compound.

[0345] From the viewpoint that the cured product has lower elasticity and excellent elongation, the content of the compound represented by formula (1) is preferably 10% by mass or more, 20% by mass or more, 30% by mass or more, or 40% by mass or more based on the total mass of the composition. The content of the compound represented by formula (1) may be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less based on the total mass of the composition.

[0346] The composition may contain only the compound represented by formula (1) as the polymerizable compound. The composition may further contain other polymerizable compounds (details will be described later) other than the compound represented by formula (1). In this case, from the viewpoint that the cured product has lower elasticity and excellent elongation, the content of the compound represented by formula (1) is preferably 20 parts by mass or more, 30 parts by mass or more, or 40 parts by mass or more with respect to 100 parts by mass of the total of the compound represented by formula (1) and other polymerizable compounds (hereinafter referred to as "total content of polymerizable components"). The content of the compound represented by formula (1) may be 80 parts by mass or less, 70 parts by mass or less, or 60 parts by mass or less with respect to 100 parts by mass of the total content of polymerizable components.

[0347] The polymerizable compound may contain other polymerizable compounds other than the compound represented by formula (1).

[0348] Other polymerizable compounds may be, for example, compounds having one (meth)acryloyl group. The compound may be, for example, an alkyl (meth)acrylate. Other polymerizable compounds may be compounds having, in addition to one (meth)acryloyl group, an aromatic hydrocarbon group, a group containing a polyoxyalkylene chain, a group containing a heterocycle, an alkoxy group, a phenoxy group, a group containing a silane group, a group containing a siloxane bond, a halogen atom, a hydroxyl group, a carboxyl group, an amino group, or an epoxy group. In particular, by containing an alkyl (meth)acrylate in the composition, the viscosity of the composition can be adjusted. Further, by containing a compound having a hydroxyl group, a carboxyl group, an amino group, or an epoxy group in addition to the (meth)acryloyl group in the composition, the adhesion of the composition to the members of the heat insulating material can be further improved.

[0349] The alkyl group in the alkyl (meth)acrylate (the alkyl group portion other than the (meth)acryloyl group) may be linear, branched, or alicyclic. The number of carbon atoms of the alkyl group may be, for example, 1 to 30. The number of carbon atoms of the alkyl group may be 1 to 11, 1 to 8, 1 to 6, or 1 to 4, or may be 12 to 30, 12 to 28, 12 to 24, 12 to 22, 12 to 18, or 12 to 14.

[0350] Examples of the alkyl (meth)acrylate having a linear alkyl group include alkyl (meth)acrylates having a linear alkyl group with 1 to 11 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, or undecyl (meth)acrylate; and alkyl (meth)acrylates having a linear alkyl group with 12 to 30 carbon atoms, such as dodecyl (meth)acrylate (lauryl (meth)acrylate), tetradecyl (meth)acrylate, hexadecyl (meth)acrylate (cetyl (meth)acrylate), octadecyl (meth)acrylate (stearyl (meth)acrylate), docosyl (meth)acrylate (behenyl (meth)acrylate), tetracosyl (meth)acrylate, hexacosyl (meth)acrylate, or octacosyl (meth)acrylate.

[0351] Examples of the alkyl (meth)acrylate having a branched alkyl group include alkyl (meth)acrylates having a branched alkyl group with 1 to 11 carbon atoms, such as s-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, isopentyl (meth)acrylate, isoamyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, or isodecyl (meth)acrylate; and alkyl (meth)acrylates having a branched alkyl group with 12 to 30 carbon atoms, such as isomyristyl (meth)acrylate, 2-propylheptyl (meth)acrylate, isoundecyl (meth)acrylate, isododecyl (meth)acrylate, isotridecyl (meth)acrylate, isopentadecyl (meth)acrylate, isohexadecyl (meth)acrylate, isoheptadecyl (meth)acrylate, isostearyl (meth)acrylate, or decyltetradecanyl (meth)acrylate.

[0352] Examples of alkyl (meth)acrylates having an alicyclic alkyl group (cycloalkyl group) include cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, terpene (meth)acrylate, dicyclopentanyl (meth)acrylate, and the like.

[0353] Examples of compounds having a (meth)acryloyl group and an aromatic hydrocarbon group include benzyl (meth)acrylate and the like.

[0354] Examples of compounds having a (meth)acryloyl group and a group containing a polyoxyalkylene chain include polyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, polybutylene glycol (meth)acrylate, methoxypolybutylene glycol (meth)acrylate, and the like.

[0355] Examples of compounds having a (meth)acryloyl group and a group containing a heterocycle include tetrahydrofurfuryl (meth)acrylate and the like.

[0356] Examples of compounds having a (meth)acryloyl group and an alkoxy group include 2-methoxyethyl acrylate and the like.

[0357] Examples of compounds having a (meth)acryloyl group and a phenoxy group include phenoxyethyl (meth)acrylate and the like.

[0358] Examples of compounds having a (meth)acryloyl group and a group containing a silane group include 3-acryloxypropyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.

[0359] Examples of the compound having a (meth)acryloyl group and a group containing a siloxane bond include silicone (meth)acrylate and the like.

[0360] Examples of the compound having a (meth)acryloyl group and a halogen atom include (meth)acrylates having a fluorine atom such as trifluoromethyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 1,1,1,3,3,3-hexafluoro-2-propyl (meth)acrylate, perfluoroethyl methyl (meth)acrylate, perfluoropropyl methyl (meth)acrylate, perfluorobutyl methyl (meth)acrylate, perfluoropentyl methyl (meth)acrylate, perfluorohexyl methyl (meth)acrylate, perfluoroheptyl methyl (meth)acrylate, perfluorooctyl methyl (meth)acrylate, perfluorononyl methyl (meth)acrylate, perfluorodecyl methyl (meth)acrylate, perfluoroundecyl methyl (meth)acrylate, perfluorododecyl methyl (meth)acrylate, perfluorotridecyl methyl (meth)acrylate, perfluorotetradecyl methyl (meth)acrylate, 2-(trifluoromethyl)ethyl (meth)acrylate, 2-(perfluoroethyl)ethyl (meth)acrylate, 2-(perfluoropropyl)ethyl (meth)acrylate, 2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluoropentyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluoroheptyl)ethyl (meth)acrylate, 2-(perfluorooctyl)ethyl (meth)acrylate, 2-(perfluorononyl)ethyl (meth)acrylate, 2-(perfluorotridecyl)ethyl (meth)acrylate, 2-(perfluorotetradecyl)ethyl (meth)acrylate, etc.

[0361] Examples of the compound having a (meth)acryloyl group and a hydroxyl group include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate; and hydroxyalkyl cycloalkane (meth)acrylates such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate and the like.

[0362] Examples of the compound having a (meth)acryloyl group and a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, phthalic acid mono-hydroxyethyl acrylate (for example, "Aronix M5400" manufactured by Toagosei Co., Ltd.), and 2-acryloyloxyethyl succinate (for example, "NK Ester A-SA" manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like.

[0363] Examples of the compound having a (meth)acryloyl group and an amino group include, for example, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N,N-diethylaminopropyl (meth)acrylate and the like.

[0364] Examples of the compound having a (meth)acryloyl group and an epoxy group include glycidyl (meth)acrylate, glycidyl α-ethyl(meth)acrylate, glycidyl α-n-propyl(meth)acrylate, glycidyl α-n-butyl(meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 4,5-epoxypentyl (meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, 6,7-epoxyheptyl α-ethyl(meth)acrylate, 3-methyl-3,4-epoxybutyl (meth)acrylate, 4-methyl-4,5-epoxypentyl (meth)acrylate, 5-methyl-5,6-epoxyhexyl (meth)acrylate, β-methylglycidyl (meth)acrylate, β-methylglycidyl α-ethyl(meth)acrylate, and the like.

[0365] The composition may contain one or more of the other polymerizable compounds as the polymerizable compound. Further, the composition may or may not further contain the compound represented by formula (1).

[0366] The content of the polymerizable compound other than the compound represented by formula (1) may be, for example, 1% by mass or more, 5% by mass or more, 10% by mass or more, 20% by mass or more, or 30% by mass or more, and may be 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total mass of the composition.

[0367] The content of the polymerizable compound (total content of the compound represented by formula (1) and other polymerizable compounds) may be, for example, 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more, and may be 95% by mass or less, or 90% by mass or less, based on the total mass of the composition.

[0368] The composition may further contain a polymerization initiator. The polymerization initiator may be, for example, a thermal polymerization initiator that generates radicals by heat, a photopolymerization initiator that generates radicals by light, or the like. The polymerization initiator is preferably a thermal polymerization initiator.

[0369] When the composition contains a thermal polymerization initiator, a cured product of the composition can be obtained by heating the composition. In this case, the composition may be a composition that is cured by heating preferably at 105°C or higher, more preferably at 110°C or higher, still more preferably at 115°C or higher, and for example, may also be a composition that is cured by heating at 200°C or lower, 190°C or lower, or 180°C or lower. The heating time when heating the composition may be appropriately selected according to the composition of the composition so that the composition is suitably cured.

[0370] Examples of the thermal polymerization initiator include azo compounds such as azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitrile, and azodibenzoyl; organic peroxides such as benzoyl peroxide, lauroyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, di-t-butyl peroxyhexahydroterephthalate, t-butyl peroxy-2-ethylhexanoate, 1,1-t-butyl peroxy-3,3,5-trimethylcyclohexane, and t-butyl peroxyisopropyl carbonate. The thermal polymerization initiator may be used alone or in combination of two or more thereof.

[0371] When the composition contains a photopolymerization initiator, for example, a cured product of the composition can be obtained by irradiating the composition with light (for example, light (ultraviolet light) including at least a part of wavelengths of 200 to 400 nm). The conditions for light irradiation may be appropriately set according to the type of the photopolymerization initiator.

[0372] Examples of the photopolymerization initiator may include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, and the like.

[0373] Examples of benzoin ether-based photoinitiators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one (e.g., "Irgacure 651" manufactured by BASF), anisole methyl ether, and the like. Examples of acetophenone-based photoinitiators include 1-hydroxycyclohexyl phenyl ketone (e.g., "Irgacure 184" manufactured by BASF), 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one (e.g., "Irgacure 2959" manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (e.g., "Irgacure 1173" manufactured by BASF), methoxyacetophenone, and the like.

[0374] Examples of α-ketol-based photoinitiators include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)-phenyl]-2-hydroxy-2-methylpropan-1-one, and the like. Examples of aromatic sulfonyl chloride-based photoinitiators include 2-naphthalenesulfonyl chloride, and the like. Examples of photoactive oxime-based photoinitiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime, and the like.

[0375] Examples of benzoin-based photoinitiators include benzoin. Examples of benzyl-based photoinitiators include benzyl. Examples of benzophenone-based photoinitiators include benzophenone, benzoyl benzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexyl phenyl ketone, etc. Examples of ketal-based photoinitiators include benzyldimethyl ketal. Examples of thioxanthone-based photoinitiators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone, etc.

[0376] As acylphosphine-based photoinitiators, there are bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-n-butylphosphine oxide, bis(2,6-dimethoxybenzoyl)-(2-methylpropan-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-(1-methylpropan-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-t-butylphosphine oxide, bis(2,6-dimethoxybenzoyl)cyclohexylphosphine oxide, bis(2,6-dimethoxybenzoyl)octylphosphine oxide, bis(2-methoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2-methoxybenzoyl)(1-methylpropan-1-yl)phosphine oxide, bis(2,6-diethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,6-diethoxybenzoyl)(1-methylpropan-1-yl)phosphine oxide, bis(2,6-dibutoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4-dimethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)(2,4-dipentoxyphenyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)benzylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylpropylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoylbenzyloctylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diethylphenylphosphine oxide, bis(2,4,(6-trimethylbenzoyl)-2,3,5,6-tetramethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)isobutylphosphine oxide, 2,6-dimethoxybenzoyl-2,4,6-trimethylbenzoyl-n-butylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-dibutoxyphenylphosphine oxide, 1,10-bis[bis(2,4,6-trimethylbenzoyl)phosphine oxide]decane, tri(2-methylbenzoyl)phosphine oxide and the like can be mentioned.,

[0377] The above-mentioned photoinitiator may be used alone or in combination of two or more kinds.,

[0378] From the viewpoint of allowing the polymerization to proceed suitably, the content of the polymerization initiator is preferably 0.01 part by mass or more, more preferably 0.02 part by mass or more, still more preferably 0.05 part by mass or more, with respect to 100 parts by mass in total of the content of the polymerizable components. From the viewpoint that the molecular weight of the polymer in the cured product of the composition is in a suitable range and suppressing decomposition products, the content of the polymerization initiator is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, particularly preferably 1 part by mass or less, with respect to 100 parts by mass in total of the content of the polymerizable components.,

[0379] The composition can contain a plasticizer as an additive. By containing a plasticizer in the composition, the adhesion of the composition and the elongation of the cured product can be further enhanced. Examples of the plasticizer include tackifiers such as butadiene rubber, isoprene rubber, silicone rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, ethylene-propylene rubber, urethane rubber, acrylic resin, rosin-based resin, terpene-based resin, or polyalkylene glycol. The content of the plasticizer may be 0.1 part by mass or more, 1 part by mass or more, or 3 part by mass or more, and may be 20 parts by mass or less, 15 parts by mass or less, 12 parts by mass or less, or 10 parts by mass or less with respect to a total of 100 parts by mass of the content of the polymerizable components.

[0380] The composition can further contain other additives as needed. Examples of the other additives include, for example, antioxidants, surface treatment agents (such as silane coupling agents), dispersants, curing accelerators, colorants, crystal nucleating agents, heat stabilizers, foaming agents, flame retardants, vibration damping agents, dehydrating agents, flame retardant aids (such as metal oxides). The content of the other additives may be 0.1% by mass or more and may be 30% by mass or less based on the total mass of the composition.

[0381] The composition is preferably liquid at 25°C. Thereby, it can be suitably applied to the surface of the object, and the adhesion to the applied surface can also be enhanced. The composition may be solid at 25°C, and in that case, it is preferably liquefied by heating (for example, at 50°C or higher). The composition may be applied in a liquid state and then cured, whereby it can be suppressed that the composition causes dripping and pump-out phenomena.

[0382] The above-described composition may be in the state of a multi-liquid composition (composition set). The composition set according to one embodiment is a composition set including a first liquid containing an oxidizing agent and a second liquid containing a reducing agent. The above-described first hollow particles, second hollow particles, and polymerizable compound are each contained in at least one of the first liquid and the second liquid. By mixing the first liquid and the second liquid, the oxidizing agent and the reducing agent react to generate free radicals, and the polymerization of the polymerizable compound proceeds. According to the composition set of the present embodiment, by mixing the first liquid and the second liquid, a cured product of the mixture of the first liquid and the second liquid can be obtained immediately. That is, according to the composition set, a cured product of the composition can be obtained at a high speed.

[0383] In the composition set, preferably, the first liquid contains an oxidizing agent, a polymerizable compound, the first hollow particles, and the second hollow particles, and the second liquid contains a reducing agent, a polymerizable compound, the first hollow particles, and the second hollow particles. More preferably, the first liquid contains an oxidizing agent, the polymerizable compound represented by the formula (1), the first hollow particles, and the second hollow particles, and the second liquid contains a reducing agent, the polymerizable compound represented by the formula (1), the first hollow particles, and the second hollow particles.

[0384] The content of the compound represented by the formula (1) based on the total mass of the liquids constituting the composition set (for example, in the case of a two-liquid composition set, the total amount of the first liquid and the second liquid) may be the same as the range of the content of the compound represented by the formula (1) based on the total mass of the above-described composition. The same applies to the content of the hollow particles contained in the composition set.

[0385] The oxidizing agent contained in the first liquid has a role as a polymerization initiator (radical polymerization initiator). The oxidizing agent may be, for example, an organic peroxide or an azo compound. The organic peroxide may be, for example, a hydroperoxide, a peroxydicarbonate, a peroxyester, a peroxyketal, a dialkyl peroxide, a diacyl peroxide, etc. The azo compound may be AIBN (2,2'-azobisisobutyronitrile), V-65 (azobisdimethylvaleronitrile), etc. The oxidizing agent can be used alone or in combination of two or more kinds.

[0386] Examples of the hydroperoxide include diisopropylbenzene hydroperoxide, cumene hydroperoxide, etc.

[0387] Examples of the peroxydicarbonate include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxymethoxy peroxydicarbonate, di(2-ethylhexylperoxy) dicarbonate, dimethoxybutyl peroxydicarbonate, di(3-methyl-3methoxybutylperoxy) dicarbonate, etc.

[0388] Examples of the peroxyester include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 1-cyclohexyl-1-methylethyl peroxy-2-ethylhexanoate, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, 1,1-bis(t-butylperoxy)cyclohexane, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, 2,5-dimethyl-2,5-di(m-toluoylperoxy)hexane, t-hexyl peroxybenzoate, t-butyl peroxyacetate, and the like.

[0389] Examples of the peroxyketal include 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclododecane, 2,2-bis(t-butylperoxy)decane, and the like.

[0390] Examples of the dialkyl peroxide include α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butyl cumyl peroxide, and the like.

[0391] Examples of the diacyl peroxide include isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide, benzoyl peroxytoluene, benzoyl peroxide, and the like.

[0392] From the viewpoint of storage stability, the oxidizing agent is preferably a peroxide, more preferably a hydroperoxide, and still more preferably cumene hydroperoxide.

[0393] The content of the oxidizing agent may be 0.1% by mass or more, 0.5% by mass or more, or 1% by mass or more, and may be 10% by mass or less, 5% by mass or less, or 3% by mass or less based on the total mass of the liquids constituting the composition set.

[0394] The reducing agent contained in the second liquid may be, for example, a tertiary amine, a thiourea derivative, a transition metal salt, or the like. Examples of the tertiary amine include triethylamine, tripropylamine, tributylamine, N,N-dimethylparatoluidine, and the like. Examples of the thiourea derivative include 2-mercaptobenzimidazole, methylthiourea, dibutylthiourea, tetramethylthiourea, ethylene thiourea, and the like. Examples of the transition metal salt include cobalt naphthenate, copper naphthenate, vanadyl acetylacetonate, and the like. The reducing agent can be used alone or in combination of two or more.

[0395] From the viewpoint of excellent curing rate, the reducing agent is preferably a thiourea derivative or a transition metal salt. The thiourea derivative may be, for example, ethylene thiourea. From the same viewpoint, the transition metal salt is preferably vanadyl acetylacetonate.

[0396] The content of the reducing agent may be 0.05% by mass or more, 0.1% by mass or more, or 0.3% by mass or more, and may be 5% by mass or less, 3% by mass or less, or 1% by mass or less based on the total mass of the liquids constituting the composition set.

[0397] The composition set may further contain the above-described additive. The additive may be contained in one or both of the first liquid and the second liquid, or may be contained in a third liquid different from the first liquid and the second liquid. The content of the additive based on the total mass of the liquids constituting the composition set may be the same as the range of the content of the additive based on the total mass of the above-described composition.

[0398] Figs. 1 to 5 are diagrams for explaining an example of a method for manufacturing a double-sided mounting substrate (hereinafter, manufacturing method (1)).

[0399] In manufacturing method (1), as shown in Fig. 1, a substrate 10 having a first main surface 10A and a second main surface 10B, and a first electronic component 21 having solder bumps 22 disposed on the connection surface are prepared, and the first electronic component 21 is disposed on the first main surface 10A of the substrate 10.

[0400] Next, the first electronic component 21 is mounted on the substrate 10. Specifically, the solder bumps 22 are melted by reflow to connect the substrate 10 and the first electronic component 21. Next, the gap between the substrate 10 and the first electronic component 21 is sealed with an underfill material. As shown in Fig. 2, the mounted first electronic component 21 is connected to the substrate 10 by a connection portion 23 made of solder, and the gap between the first electronic component 21 and the substrate 10 is sealed with a sealing material 24 made of an underfill material or a cured product thereof.

[0401] Next, as shown in Fig. 3, the mounted first electronic component 21 is covered with a heat insulating material 30, held by a holding member 40, the whole is turned over, and a second electronic component 51 is disposed on the second main surface 10B.

[0402] Next, the second electronic component 51 is mounted on the substrate 10. Specifically, the solder bumps 52 are melted by reflow to connect the substrate 10 and the second electronic component 51. Next, the gap between the substrate 10 and the second electronic component 51 is sealed with an underfill material. As shown in FIG. 4, the mounted second electronic component 51 is connected to the substrate 10 by a connection portion 53 made of solder, and the gap between the second electronic component 51 and the substrate 10 is sealed with a sealing material 54 made of an underfill material or a cured product thereof.

[0403] Thereafter, by removing the holding member 40 and the heat insulating material 30, the double-sided mounting substrate shown in FIG. 5 is obtained.

[0404] In the manufacturing method (1), the heat insulating material 30 is arranged so as to directly contact the first electronic component 21, but in the present embodiment, the arrangement of the heat insulating material is not limited to this. For example, as shown in FIG. 6, the heat insulating material may be arranged on one surface of the holding member 40 to form a heat insulating layer 31. In other words, in the manufacturing method of the present embodiment, the holding step may be performed using a holding member including a base body 40 and a heat insulating layer 31 as the holding member.

Description of Reference Numerals

[0405] 10... Substrate, 21... First electronic component, 22, 52... Solder bumps, 23, 53... Connection portions, 24, 54... Sealing materials, 30... Heat insulating material, 31... Heat insulating layer, 40... Holding member, 51... Second electronic component.

Claims

1. A first mounting step of mounting a first electronic component on the first main surface of a substrate having a first main surface and a second main surface; A holding step of disposing a holding member for holding the first electronic component on the first main surface; A second mounting step of mounting a second electronic component on the second main surface; Comprising: A method for manufacturing a double-sided mounting substrate, wherein, before the second mounting step, a heat insulating material satisfying the following formula (A) is disposed so as to surround the first electronic component mounted on the first main surface. F1 > F2 … (A) [In the formula, F1 represents the adhesive force of the heat insulating material after heating the heat insulating material at 220°C for 120 seconds, and F2 represents the adhesive force of the heat insulating material after heating the heat insulating material at 260°C for 30 seconds.]

2. Further comprising a covering step of covering the first electronic component with a heat insulating material after the first mounting step, The manufacturing method according to claim 1, wherein the holding member is a member for holding the first electronic component covered with the heat insulating material on the first main surface.

3. The manufacturing method according to claim 1, wherein the holding step is a step of disposing a holding member including a base body and a heat insulating layer containing a heat insulating material disposed on the base body.

4. The manufacturing method according to any one of claims 1 to 3, wherein the heat insulating material contains aerogel particles.

5. The manufacturing method according to claim 4, wherein the heat insulating material further contains a water-soluble polymer having a hydrophobic group.

6. The manufacturing method according to any one of claims 1 to 3, wherein the heat insulating material contains first hollow particles which are thermally expandable hollow particles, second hollow particles which are hollow particles other than the first hollow particles, and a matrix polymer.

7. A holding member for holding a first electronic component mounted on the first main surface of a substrate having a first main surface and a second main surface on the first main surface when a second electronic component is mounted on the second main surface, Comprising a base body; A heat insulating layer containing a heat insulating material disposed on the base body; Comprising: The heat insulating material satisfies the following formula (A). F1 > F2 … (A) [In the formula, F1 represents the adhesive force of the heat insulating material after heating the heat insulating material at 220°C for 120 seconds, and F2 represents the adhesive force of the heat insulating material after heating the heat insulating material at 260°C for 30 seconds.]

Images