JP7653230B2 - Composition for forming heat insulating layer and heat insulating member - Google Patents

Description

The present invention relates to a composition for forming a heat insulating layer and a heat insulating member.

For example, JP 2001-240809 A discloses a composition for forming a heat insulating layer that contains a binder resin, hollow particles, and heat-fusible fibers as a composition for forming a heat insulating layer on building materials such as the interior and exterior walls of buildings and sashes.

JP 2001-240809 A

As DIY and other methods have become more widespread, people are now doing things like forming an insulating layer on aluminum sashes and the like at home. In these cases, it is not only necessary to be able to form the insulating layer with simple steps, but also to be able to peel the insulating layer off cleanly after use, for example, during the off-season.

The present invention was made based on the above-mentioned circumstances, and its purpose is to provide a composition for forming an insulating layer and an insulating member that can form an insulating layer that has excellent peelability, drying properties, and insulating properties.

The invention made to solve the above problem is a composition for forming a heat insulating layer, which contains a binder resin, hollow particles, and water, in which the hollow particle content is 30% by volume or more and 75% by volume or less, and the water content is 30% by volume or less.

Another invention made to solve the above problem is an insulating member comprising a substrate and an insulating layer laminated directly or indirectly on the substrate, the insulating layer being formed from the above-mentioned composition for forming the insulating layer.

The composition for forming a heat insulating layer and the heat insulating member of the present invention can form a heat insulating layer that has excellent peelability, drying properties, and heat insulating properties.

The composition for forming a heat insulating layer and the heat insulating member of the present invention are described in detail below.

<Composition for forming heat insulating layer>
The composition for forming a heat insulating layer contains a binder resin (hereinafter also referred to as "binder resin [A]"), hollow particles (hereinafter also referred to as "hollow particles [B]"), and water (hereinafter also referred to as "water [C]"). The composition for forming a heat insulating layer may contain other components (hereinafter also simply referred to as "other components") other than the binder resin [A], the hollow particles [B], and the water [C], as necessary, within a range that does not impair the effects of the present invention.

According to the composition for forming a heat insulating layer, a heat insulating layer having excellent peelability, drying property and heat insulating property can be formed. The reason why the composition for forming a heat insulating layer has the above-mentioned constitution and thereby exhibits the above-mentioned effect is not necessarily clear, but it can be presumed, for example, as follows.
In other words, by setting the content of hollow particles [B] in the composition for forming an insulating layer to 30 volume % or more and 75 volume % or less, an insulating layer having excellent peelability and insulating properties can be formed, and by setting the content of water [C] to 30 volume % or less, it is believed that the composition has excellent drying properties.

The components contained in the composition for forming the heat insulating layer are described below.

[[A] Binder resin]
[A] The binder resin is not particularly limited as long as it is a resin that dissolves or disperses in [C] water, and examples thereof include acrylic resins, polyvinyl acetate resins, ethylene/vinyl acetate resins, polyvinyl chloride resins, vinyl chloride/vinyl acetate resins, polyamide resins, cellulose acetate, cellulose butyrate, ethyl cellulose, polyvinyl alcohol, chlorinated polypropylene, urea resins, melamine resins, epoxy resins, phenolic resins, furan resins, alkyd resins, unsaturated polyester resins, silicon resins, fluorine resins, polyurethane resins, acrylic urethane resins, natural rubber, reclaimed rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, polysulfide rubber, silicone rubber, polyurethane rubber, stereo rubber (synthetic natural rubber), ethylene propylene rubber, block copolymer rubber (SBS, SIS, SEBS, etc.), etc. The heat insulation layer forming composition may contain one or more [A] binder resins.

[A] The binder resin is preferably a copolymer of at least one vinyl monomer selected from the group consisting of (meth)acrylic acid esters, styrene, vinyl acetate, diene compounds, and vinyl chloride, or a urethane resin.

The glass transition temperature (Tg) of the binder resin [A] is preferably -100°C or higher and 0°C or lower. In particular, if the Tg of the binder resin [A] exceeds the above upper limit, the peelability of the heat insulating layer formed from the heat insulating layer forming composition may deteriorate. The Tg of the binder resin [A] is a value measured using a differential scanning calorimeter ("DSC Q200" by TI Instruments Japan, Ltd.).

[A] Commercially available products may be used as the binder resin. Examples of commercially available products include "JSR SBLTX 0561" from JSR Corporation, "AE299", "AE887", and "AE872D" from E-Tech Co., Ltd., and "Superflex E-200" from Daiichi Kogyo Seiyaku Co., Ltd.

The binder resin [A] may be used in the form of an emulsion in which it has been dissolved or dispersed in water [C] beforehand.

[[B] Hollow particles]
The hollow particles (B) are particles having closed voids inside the particles. The term "closed voids" refers to voids that are completely closed by the particle shell or voids that are not completely closed but are closed by the particle shell to such an extent that other components such as the binder resin (A) cannot penetrate into the voids.

The composition for forming a heat insulating layer contains hollow particles [B], so that a heat insulating layer having closed bubbles can be formed.

The content of hollow particles [B] in the composition for forming the insulating layer is 30% by volume or more and 75% by volume or less. By setting the content of hollow particles [B] within the above range, it is possible to form an insulating layer that has excellent peelability and insulating properties.

The lower limit of the content of hollow particles [B] in the composition for forming a thermal insulation layer is preferably 35 vol%, more preferably 40 vol%, and even more preferably 45 vol%. By setting the lower limit of the content of hollow particles [B] within the above range, the thermal insulation of the thermal insulation layer formed by the composition for forming a thermal insulation layer can be further improved. The upper limit of the content of hollow particles [B] is preferably 70 vol%, more preferably 65 vol%, and even more preferably 60 vol%. By setting the upper limit of the content of hollow particles [B] within the above range, the peelability of the thermal insulation layer formed by the composition for forming a thermal insulation layer can be further improved.

The material of the hollow particles [B] may be an organic material or an inorganic material. Examples of organic materials include synthetic resins such as acrylic resins, acrylonitrile resins, styrene resins, polyesters, polyurethanes, epoxy resins, and polyvinyl chloride resins. Examples of inorganic materials include metal oxides such as silica, alumina, titania, and zirconia, and metal halides such as magnesium fluoride. Among these, the material of the hollow particles [B] is preferably a synthetic resin, and more preferably an acrylic resin, an acrylonitrile resin, a styrene resin, polyesters, polyurethanes, epoxy resins, or polyvinyl chloride resins. The composition for forming a heat insulating layer can contain one or more types of hollow particles [B].

The lower limit of the average particle diameter of the hollow particles [B] is preferably 0.1 μm, and more preferably 0.5 μm. The upper limit of the average particle diameter of the hollow particles [B] is preferably 100 μm, and more preferably 50 μm. By setting the average particle diameter of the hollow particles [B] within the above range, the dispersion stability during blending can be improved. The average particle diameter of the hollow particles [B] is the volume average particle diameter (D50) measured by a laser diffraction method.

The lower limit of the specific gravity of the hollow particles [B] is preferably 0.01, and more preferably 0.02. The upper limit of the specific gravity of the hollow particles [B] is preferably 0.5, and more preferably 0.1. By setting the specific gravity of the hollow particles [B] within the above range, the thermal insulation of the thermal insulation layer formed by the composition for forming a thermal insulation layer can be further improved. The specific gravity of the hollow particles [B] is a value measured in accordance with JIS-Z8807 (2012).

[B] As the hollow particles, commercially available products may be used. Examples of commercially available products include "Expancel 921WE40d24" from Nippon Fillite Co., Ltd. and "Microsphere F-65E" from Matsumoto Yushi Seiyaku Co., Ltd.

[C] Water
The water (C) is used to dissolve or disperse the binder resin (A), the hollow particles (B), and the like.

The content of water [C] in the composition for forming the insulating layer is 30% by volume or less. By setting the content of water [C] within the above range, an insulating layer with excellent drying properties can be formed.

[C] The lower limit of the water content is preferably 5% by volume, and more preferably 10% by volume. [C] The upper limit of the water content is preferably 25% by volume. By setting the upper limit of the water content in the above range, the drying property of the insulating layer formed by the insulating layer forming composition can be further improved.

(Other ingredients)
Examples of other components include thickeners, defoamers, wetting agents, dispersants, organic solvents, preservatives, antifreezing agents, pigments, dyes, UV absorbers, antioxidants, light stabilizers, and rust inhibitors. The heat insulating layer forming composition may contain one or more other components. The content of the other components in the heat insulating layer forming composition may be appropriately determined depending on the type of components used.

Examples of thickeners include alkali thickeners and association type thickeners. The content of the thickener in the composition for forming the heat insulating layer can be, for example, 0.01% by mass or more and 5% by mass or less.

The composition for forming a heat insulating layer can be prepared, for example, by preparing a dispersion of [C] water containing [A] binder resin, and mixing this dispersion with [B] hollow particles and other components as necessary. The lower limit of the solid content concentration of the composition for forming a heat insulating layer is preferably 10% by mass, and more preferably 20% by mass. The upper limit of the solid content concentration of the composition for forming a heat insulating layer is preferably 70% by mass, and more preferably 60% by mass. Note that "solid content" refers to components other than volatile components such as [C] water contained in the composition for forming a heat insulating layer.

The specific gravity of the composition for forming the heat insulating layer is preferably 0.2 or more and 0.6 or less. The specific gravity of the composition for forming the heat insulating layer is a value measured in accordance with JIS-Z8804 (2012).

The composition for forming a heat insulating layer is used to form a heat insulating layer. More specifically, the composition for forming a heat insulating layer is applied to a substrate and used to form a heat insulating layer on the substrate.

The substrate is not particularly limited, but examples include aluminum, stainless steel, iron, copper, galvanized iron, polypropylene (PP), polyethylene (PE), polycarbonate, acrylic, polyphenylene sulfide (PPS), acrylonitrile-styrene-butadiene (ABS), wood, concrete, asphalt, glass, tiles, bricks, paper, cardboard, and other building materials, automobiles, and packaging materials.

The method for applying the composition for forming a heat insulating layer to the substrate is not particularly limited, and examples of the method include a coating method using a spatula or roller, and a method in which the composition is extruded from a tubular container and applied to the substrate. After application to the substrate, the composition may be dried at room temperature, or may be dried by heating at, for example, 40°C to 120°C.

According to this composition for forming a heat insulating layer, a heat insulating layer can be formed by a simple operation of coating the substrate. Therefore, the work of forming a heat insulating layer on a building material such as an aluminum sash can be easily performed by an individual as part of a DIY project, rather than by a professional. In addition, since the formed heat insulating layer has excellent peelability, it can be easily peeled off by hand even when the heat insulating layer is no longer needed due to reasons such as the off-season or deterioration over time. This composition for forming a heat insulating layer is not only excellent in terms of convenience for workers, such as drying and peelability, but also has excellent heat insulating properties required for a heat insulating layer.

The heat insulating layer formed by the composition for forming a heat insulating layer can maintain high and low temperatures, and by maintaining these conditions, energy can be saved. In addition, it has the effect of suppressing the impact of high and low temperatures on the surrounding environment, and preventing burns and frostbite from direct contact with objects in these conditions. For example, it is useful in preventing condensation in aluminum sashes that separate the indoor and outdoor areas, which have a temperature difference, in winter. Specific applications include building materials to prevent condensation on aluminum sashes, insulation for automobiles, and also use as an insulating cushioning material for window glass, packaging materials, wrapping materials, etc.

<Thermal insulation materials>
The heat insulating member includes a base material and a heat insulating layer laminated directly or indirectly on the base material. The heat insulating layer is formed from the heat insulating layer forming composition described above. Therefore, the heat insulating member can be suitably used as a member that exhibits excellent heat insulating properties.

The substrate is not particularly limited, but examples include aluminum, stainless steel, iron, copper, galvanized iron, polypropylene (PP), polyethylene (PE), polycarbonate, acrylic, polyphenylene sulfide (PPS), acrylonitrile-styrene-butadiene (ABS), wood, concrete, asphalt, glass, tiles, bricks, paper, cardboard, and other building materials, automobiles, and packaging materials.

The insulating layer is a layer with a closed cell structure formed by the insulating layer forming composition described above. The average thickness of the insulating layer can be appropriately determined depending on the intended use of the insulating member, and can be, for example, 0.5 mm or more and 20 mm or less. The average thickness of the insulating layer can be appropriately adjusted by the amount of the insulating layer forming composition applied, etc. The average thickness of the insulating layer is the average thickness of any 10 points.

The lower limit of the specific gravity of the insulating layer is preferably 0.1, and more preferably 0.2. The upper limit of the specific gravity of the insulating layer is preferably 0.5, and more preferably 0.4. By setting the specific gravity of the insulating layer within the above range, the peelability and heat insulation of the insulating layer can be further improved.

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

<Preparation of composition for forming heat insulating layer>
The components used in the preparation of the composition for forming a heat insulating layer are shown below.

([A] Binder Resin)
(A-1): Styrene-butadiene rubber ("JSR SBLTX 0561" from JSR Corporation, Tg: -63°C)
(A-2): Acrylic resin ("AE299" by E-Tech Co., Ltd., Tg: -60°C)
(A-3): Urethane resin (Dai-ichi Kogyo Seiyaku Co., Ltd.'s "Superflex E-200", Tg: -38°C)
(A-4): Acrylic resin ("AE872D" by E-Tech Co., Ltd., Tg: 15°C)

([B] Hollow particles)
(B-1): Acrylic hollow particles ("Expancel 921WE40d24" by Nippon Phillite Co., Ltd., specific gravity: 0.024, average particle size: 45 μm)
(B-2): Acrylonitrile-based hollow particles ("F-65E" by Matsumoto Yushi Seiyaku Co., Ltd., specific gravity: 0.025, average particle size: 50 μm)

(Other ingredients)
Thickener: San Nopco Ltd.'s "SN Thickener A-812"

[Example 1] Preparation of a composition for forming a heat insulating layer (E-1) [A] While stirring 145 parts by mass of the aqueous dispersion of (A-1) as a binder resin (containing 69 parts by mass of (A-1)), 299 parts by mass of (B-1) as hollow particles [B] and 0.1 parts by mass of a thickener were added in this order to prepare a composition for forming a heat insulating layer (E-1). The solid content concentration of the composition for forming a heat insulating layer (E-1) was 30% by mass.

[Examples 2 to 7 and Comparative Examples 1 to 4] Preparation of compositions for forming a heat insulating layer (E-2) to (E-7) and (CE-1) to (CE-4) Compositions for forming a heat insulating layer (E-2) to (E-7) and (CE-1) to (CE-4) were prepared in the same manner as in Example 1, except that the types and amounts of each component shown in Table 1 below were used.

In Table 1 below, the values in the rows for [A] binder resin, [B] hollow particles, and [C] water and thickener represent parts by mass. In Table 1 below, "-" indicates that the corresponding component was not added. For example, in the column for Example 1 in Table 1 below, the row for "Water" is marked with "-". This does not mean that the heat insulating layer forming composition (E-1) does not contain water, but rather that no water was added other than the water contained in the aqueous dispersion of (A-1) when (E-1) was prepared.

(Measurement of specific gravity of composition for forming heat insulating layer)
The specific gravity of each of the compositions for forming a heat insulating layer prepared above was measured in an atmosphere of 23° C. and 50% Rh in accordance with JIS-Z8804 (2012).

(Measurement of specific gravity of binder resin, hollow particles and heat insulating layer)
The binder resin, hollow particles, and heat insulating layer were dried by heating at 40° C. for 72 hours, and after thorough drying, the specific gravity was measured in an atmosphere of 23° C. and 50% Rh in accordance with JIS-Z8807 (2012).

(Calculation of volume fraction of each component)
The volume fractions of the binder resin (A), the hollow particles (B) and the water (C) in the composition for forming a heat insulating layer were calculated using the following formulas (1) to (3). The calculation results are shown in Table 1 below.
[A] Volume fraction of binder resin=(Wr/Dr)/(Wf/Df) (1)
[B] Volume fraction of hollow particles = (Wp / Dp) / (Wf / Df) ... (2)
[C] Volume fraction of water = (Ww/Dw)/(Wf/Df) ... (3)

The abbreviations used in the above formulas (1) to (3) are as follows:
Wr: [A] Mass of binder resin Dr: [A] Specific gravity of binder resin Wf: Mass of composition for forming a heat insulating layer Df: Specific gravity of composition for forming a heat insulating layer Wp: [B] Mass of hollow particles Dp: [B] Specific gravity of hollow particles Ww: [C] Mass of water Dw: [C] Specific gravity of water (constant 1)

<Formation of heat insulating layer>
A 2.7 mm thick SUS plate was placed around an aluminum substrate (A6063 with anodized surface) of 70 mm x 150 mm. The heat insulating layer forming composition prepared above was poured into the substrate and leveled with a spatula to the same thickness as the SUS plate. After drying for 24 hours in a 23°C, 50% Rh environment, the SUS plate was removed and a heat insulating layer was formed on the aluminum substrate. The thickness of the obtained heat insulating layer was 2 mm.

<Evaluation>
The peelability, drying property and heat insulation property were evaluated according to the following methods, and the results are shown in Table 1 below.

[Removability]
The heat insulating layer formed above was checked for its ability to be peeled off from the aluminum substrate by pinching it with fingers. The peelability was evaluated as "A" (good) when the heat insulating layer was peeled off cleanly without remaining on the aluminum substrate surface, "B" (fairly good) when a small amount of the heat insulating layer remained on the aluminum substrate surface but could be wiped off, and "C" (poor) when a large amount of the heat insulating layer remained on the aluminum substrate surface.

[Drying property]
A 2 mm thick heat insulating layer was formed in the same manner as in the above "Formation of Heat Insulating Layer" except that the base material was release paper and the drying time was 12 hours. The heat insulating layer on the formed release paper was peeled off, and the surface of the heat insulating layer that had been in contact with the release paper (hereinafter also referred to as the "reverse side") was touched with a finger. If there was no moisture, it was rated as "A"(good); if the reverse side was slightly damp, it was rated as "B" (slightly good); and if water droplets remained on the reverse side or part of the heat insulating layer remained on the release paper, it was rated as "C" (bad).

[Thermal insulation]
A 2 mm insulating layer was formed in the same manner as in the above "Formation of an insulating layer" except that the base material was release paper and the drying time was 24 hours. The insulating layer formed on the release paper was peeled off and cut out to 20 mm x 40 mm. The cut insulating layer was attached to the outer side of a SUS container, ice water was placed in the container, and the container was left to stand for 2 hours under an atmosphere of 23 ° C. and 50 Rh%. If no condensation occurred on the surface of the insulating layer after 2 hours, it was evaluated as "A" (good), if a small amount of condensation occurred, it was evaluated as "B" (slightly good), and if condensation occurred, it was evaluated as "C" (bad).

As is clear from the results in Table 1, the insulating layer formed using the insulating layer forming composition of the Example had superior peelability, drying properties, and insulating properties compared to the insulating layer formed using the insulating layer forming composition of the Comparative Example.

Claims (6)

A binder resin;
Hollow particles;
Contains water and
The content of the hollow particles is 30% by volume or more and 75% by volume or less,
The water content is 30% by volume or less,
The glass transition temperature of the binder resin is −100° C. or higher and 0° C. or lower,
The composition for forming a heat insulating layer having peelability, wherein the hollow particles are synthetic resin particles. The composition for forming a heat insulating layer having peelability according to claim 1, wherein the binder resin is a copolymer obtained by polymerizing at least one vinyl monomer selected from the group consisting of (meth)acrylic acid esters, styrene, vinyl acetate, diene compounds and vinyl chloride, or a urethane-based resin. 3. The composition for forming a heat insulating layer having peelability according to claim 1 or 2, wherein the hollow particles have an average particle size of 0.1 μm or more and 200 μm or less. The composition for forming a heat insulating layer having peelability according to any one of claims 1 to 3, wherein the specific gravity of the hollow particles is 0.01 or more and 0.5 or less. A thermal insulation member comprising a substrate and a thermal insulation layer laminated directly or indirectly on the substrate,
A heat insulating member, wherein the heat insulating layer is formed from the composition for forming a heat insulating layer having peelability according to any one of claims 1 to 4. The heat insulating member according to claim 5, wherein the specific gravity of the heat insulating layer is 0.1 or more and 0.5 or less.