JP2018111760A - Composition for forming heat insulating layer and manufacturing method of heat insulating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for forming a heat insulating layer excellent in temporal stability during storage, and forming a heat insulating layer consisting of an expanded capsule-containing resin film formed by expanding a thermal expanding microcapsule by heating the film on a surface of a substrate at high efficiency and a manufacturing method of a heat insulating material.SOLUTION: A composition for forming a heat insulating layer contains 18 to 40 mass% of a resin for forming a film, 5 to 22 mass% of a thermal expanding microcapsule with expansion initiation temperature of 80°C to 150°C, 7 to 20 mass% of alcohol and 30 to 56 mass% of water based on 100 mass% of total thereof.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a composition for forming a heat insulating layer which forms a heat insulating layer on the surface of a base material to give a composite material (heat insulating material) excellent in heat insulating properties, and a method for manufacturing the heat insulating material.

  Conventionally, a composite material in which a resin-based heat insulating layer is formed on the surface of a base material is widely used as a heat insulating material in the fields of building materials, electrical products, food, clothing, automobiles, and the like. As a material for forming such a heat insulating layer, a liquid composition that is applied to a substrate and then dried, a resin composition that is used for injection molding, or the like is generally used.

The liquid composition which gives a heat insulation layer by application | coating to a base material, drying, etc. is disclosed by patent document 1 and 2, for example.
Patent Document 1 discloses a composition used for forming a decorative sheet or the like having heat insulation properties, and 10 to 120 parts by mass of hollow particles and 50 to 5000 parts by mass of a solvent or dispersant with respect to 100 parts by mass of the binder resin. A coating composition for forming a heat-insulating layer in which parts are blended is disclosed.
Patent Document 2 discloses a heat insulating paper used for forming a heat insulating paper container or the like, and this heat insulating paper is an aqueous solution containing an acrylic resin on at least one side of a paper base material mainly made of pulp. It is described that it was obtained using a coating composition in which hollow particles having cavities are dispersed.

JP 2001-220552 A JP 2006-233386 A

  An object of the present invention is excellent in stability over time during storage, and a heat insulating layer comprising an expanded capsule-containing resin film formed by expansion of thermally expandable microcapsules by heating of the coating film is efficiently applied to the surface of the substrate. It is providing the manufacturing method of the composition for heat insulation layer formation and heat insulating material to form.

The present invention is shown below.
1. The resin for forming a film, the thermally expandable microcapsule having an expansion start temperature of 80 ° C. to 150 ° C., alcohol, and water are 18 to 40% by mass and 5 to 22 respectively when the total of these is 100% by mass. A composition for forming a heat insulating layer, comprising: mass%, 7 to 20 mass%, and 30 to 56 mass%.
2. Item 2. The heat insulating layer forming composition according to Item 1, wherein the film forming resin includes a polyurethane resin having a glass transition temperature of -70 ° C to -50 ° C.
3. Item 3. The composition for forming a heat insulation layer according to Item 1 or 2, wherein the thermally expandable microcapsule is obtained by encapsulating a liquid compound in an outer shell made of a thermoplastic resin material.
4). Item 4. The composition for forming a heat insulation layer according to any one of Items 1 to 3, wherein the alcohol contains isopropyl alcohol.
5). A method of manufacturing a heat insulating material,
The step of applying the composition for forming a heat insulating layer according to any one of Items 1 to 4 to the surface of the substrate, heating the obtained coating film to evaporate alcohol and water, A method for producing a heat insulating material, comprising sequentially forming a film while expanding the thermally expandable microcapsules contained in the coating film.

After forming a coating film on the surface of the substrate using the composition for forming a heat insulating layer of the present invention, by heating the obtained coating film, the thermally expandable microcapsules are volume-expanded, and the coating film forming resin is used. A heat insulating material having a heat insulating layer made of an expanded capsule-containing resin film containing a dispersed phase consisting of expanded capsules in the matrix phase can be produced. It is possible to suppress a specific component, for example, a thermally expandable microcapsule from settling and lowering the uniformity, and it is excellent in storage stability. Therefore, since the dispersibility of the film-forming resin and the heat-expandable microcapsules is good, the film-forming resin and the heat-expandable microcapsules are uniformly distributed when applied to the substrate during the production of the heat insulating material. A distributed coating film is obtained, and a heat insulating material including a heat insulating layer with small variation in the size of the expanded capsule can be efficiently produced. Such a heat insulating material can be widely used in the fields of building materials, electrical products, food, clothing, automobiles and the like.

It is a schematic sectional drawing which shows one example of a heat insulating material. 2 is an image showing a cross section of the heat insulating paper obtained in Example 1. FIG. 2 is an image showing the surface of a heat insulating layer of heat insulating paper obtained in Example 1. FIG. 3 is a schematic cross-sectional view showing a resin cup before producing a heat retaining cup in Example 1. FIG. 2 is a schematic cross-sectional view showing a heat retaining cup obtained in Example 1. FIG.

In the present invention, a coating, spraying or the like is applied to the surface of an object to be coated (substrate) such as paper, a resin film, a resin molded body, an inorganic material molded body, and the like, and then the coating film is heat treated. A liquid composition suitable for forming a heat-insulating film by (heat drying), containing a film-forming resin, a thermally expandable microcapsule having an expansion start temperature of 80 ° C. to 150 ° C., alcohol and water It is a composition for heat insulation layer formation. By heat treatment (heat drying) of the coating film, the thermally expandable microcapsules are expanded in volume to become expanded capsules, and these expanded capsules exist as a dispersed phase inside the film, and a heat insulating effect is imparted.
The composition for forming a heat insulating layer of the present invention includes an adhesion improver, a filler, a viscosity modifier, an antioxidant, an ultraviolet absorber, a stabilizer, a flame retardant, an antistatic agent, an antifungal agent, a colorant and the like. The component of this can be contained.

  Hereinafter, the composition for heat insulation layer formation of this invention is demonstrated.

  The film-forming resin is not particularly limited as long as it forms a film by heating and drying a coating obtained using a liquid composition containing the resin. The film-forming resin according to the present invention may be either a film that forms a film by a single substance or a film that forms a film by reaction of two or more substances. The composition in the latter case It is assumed that the content ratio is calculated using the amount of resin formed by the reaction.

  Examples of the film-forming resin include urethane resin, acrylic resin, styrene resin, vinyl chloride resin, polyester resin, alkyd resin, polyamide resin, polyamideimide resin, polyimide resin, epoxy resin, phenoxy resin, and their silicone modified products or silanes. Examples include modified products. In the present invention, a urethane resin, an acrylic resin, a styrene resin, a chloride, etc. having water resistance or solvent resistance of a film formed by heating and drying a coating film comprising the heat insulating layer forming composition, adhesion to a substrate, and the like. A vinyl resin or a modified product thereof is preferable, and among these, a urethane resin which is dissolved in an alcohol aqueous solution or has good dispersibility in an alcohol aqueous solution or a modified product thereof is particularly preferable.

  As the urethane resin, for example, a urethane prepolymer raw material having a carboxyl group and having an isocyanate group at a molecular terminal is reacted with a compound having a hydroxyl group and a polymerizable unsaturated bond, and the isocyanate group and the hydroxyl group are reacted. After obtaining a urethane prepolymer containing a urethane bond due to a group, the urethane prepolymer is dispersed in a liquid containing alcohol, water, a neutralizing agent and a chain extender to have a polymerizable unsaturated bond at the molecular end. A resin obtained by generating a urethane resin raw material and then polymerizing a polymerizable unsaturated bond can be obtained.

The urethane prepolymer raw material can be obtained by reacting a diol having a carboxyl group, a polyol, and a polyisocyanate. Preferably, the equivalent of the isocyanate group is more than the total equivalent of the hydroxyl group. It was obtained.
Examples of the diol having a carboxyl group include α, α′-dimethylolalkanoic acid (glyceric acid, dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolpentanoic acid, etc.), dioxymaleic acid, dioxyfumaric acid, Examples include tartaric acid, 2,6-dioxybenzoic acid, 4,4-bis (hydroxyphenyl) valeric acid, 4,4-bis (hydroxyphenyl) butyric acid, and the like.
Polyols include polyether polyols such as polyethylene glycol, polypropylene glycol, and polyoxytetramethylene ether glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, etc .; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, Saturated or unsaturated low molecular weight glycols such as 1,4-butynediol, dipropylene glycol, bisphenol A, hydrogenated bisphenol A, and adipic acid, maleic acid, fumaric acid Dehydration condensation with dibasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, suberic acid or the corresponding acid anhydrides Polyester polyol obtained by reaction; polycarbonate polyol and the like.
Examples of polyisocyanates include diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, xylene diisocyanate, tetramethylxylylene diisocyanate, and tolidine diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, ricintri Aliphatic isocyanates such as isocyanates; Cycloaliphatic isocyanates such as isophorone diisocyanate, cyclohexyl diisocyanate, hydrogenated XDI, and hydrogenated MDI; Urethane modified products, dimers, trimers, carbodiimide modified products, and allophanates of the above isocyanate compounds Modified body, burette modified body, urea modified body, isocyanu Over preparative modified products, oxazolidone modified product, modified isocyanates such as isocyanate group-terminated prepolymer and the like.

  Then, as a compound having a hydroxyl group and a polymerizable unsaturated bond to be reacted with the urethane prepolymer raw material, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate , 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, glycerol di (meth) acrylate, glycerol (meth) acrylate, trimethylolpropane diallyl ether, glycerol mono ( (Meth) acrylate, glycidol / acrylic acid adduct, pentaerythritol tri (meth) acrylate, pentaerythritol triallyl ether, 2-hydroxyethyl monovinyl ether, 4- B carboxybutyl monovinyl ether, N- methylol acrylamide, polypropylene glycol (meth) acrylate, polyethylene glycol (meth) acrylates, polycaprolactone (meth) acrylate. These are used in such a ratio that some isocyanate groups remain in the resulting urethane prepolymer.

  Next, the urethane prepolymer is mixed with alcohol such as ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-pentanol, sec-amyl alcohol; water; water Alkali metal hydroxides such as sodium oxide and potassium hydroxide, tertiary amines such as trimethylamine, triethylamine, triisopropylamine and tributylamine, triethanolamine, triisopropanolamine, N-alkyldiethanolamine, N, N'-dialkyl Alkanolamines such as monoethanolamine, N-alkyldiisopropanolamine, N, N′-dialkylmonoisopropanolamine, neutralizing agents such as ammonia; and ethylenediamine Aliphatic diamines such as propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4′-diamine; 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxy Diamines having a hydroxyl group in the molecule such as ethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine; alkylene dimers such as methylenedihydrazine, ethylenedihydrazine, propylenedihydrazine Hydrazine, adipic acid dihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, phthalic acid dihydrazide, Saturated or unsaturated dihydrazine such as diacid dihydrazide; Urethane having a polymerizable unsaturated bond at the molecular end by dispersing in a solution containing a chain extender such as dimeramine converted from dimer acid carboxyl group to amino group A resin raw material is produced.

  Thereafter, a polymerizable unsaturated bond of the urethane resin raw material is polymerized using a radical polymerization method or the like to obtain a high molecular weight urethane resin dispersion.

  The glass transition temperature of the film-forming resin is preferably −70 ° C. to obtain a preferable volume expansion property of the heat-expandable microcapsule when the coating film made of the heat-insulating layer-forming composition is heat-dried. It is -50 degreeC, More preferably, it is -65 degreeC--55 degreeC.

  In the thermally expandable microcapsule, an encapsulated substance (a gas, or a solid or liquid that is vaporized by heating) that increases its occupied volume by heating is preferably enclosed in an outer shell made of a resin material. It is a particulate microcapsule, and the thermally expandable microcapsule according to the present invention is a microcapsule that expands in volume when heated at 80 ° C. to 150 ° C. The above temperature is an expansion start temperature, and when the thermally expandable microcapsule having such properties is heated to reach the expansion start temperature, the encapsulated substance expands in volume and the resin material constituting the outer shell softens. A capsule (expanded capsule) expanded by the internal pressure is obtained. In the present invention, the thermally expandable microcapsule is more preferably one in which a liquid compound is encapsulated inside an outer shell made of a thermoplastic resin material (resin composition).

The liquid compound that is the inclusion substance constituting the thermally expandable microcapsule preferably has a boiling point (atmospheric pressure condition) that is not higher than the softening temperature of the resin material that constitutes the outer shell of the thermally expandable microcapsule. n-butane, isobutane, cyclobutane, n-pentane, isopentane, cyclopentane, n-hexane, 2-methylpentane, 2,2-dimethylbutane, cyclohexane, n-heptane, cycloheptane, n-octane, cyclooctane, etc. Hydrocarbon: Hydrofluoroether compounds such as C ₃ F ₇ OCH ₃ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H _{5 and the} like. The liquid compound may be only one type or two or more types. As said liquid compound, a hydrocarbon is preferable and it is especially preferable that the C4-5 low boiling point hydrocarbon is included. In addition, the resin material constituting the outer shell is acrylonitrile, methacrylonitrile, alkyl acrylate ester, alkyl methacrylate ester, vinyl chloride, vinylidene chloride, vinyl acetate, aromatic vinyl compound, acrylic acid, methacrylic acid, maleic acid, Derived from at least one selected from fumaric acid, itaconic acid, citraconic acid, acrylamide, substituted acrylamide, methacrylamide, substituted methacrylamide, and a polyfunctional compound having two or more polymerizable carbon-carbon unsaturated bonds It is preferable to contain a thermoplastic resin containing a structural unit. Examples of this thermoplastic resin include polyvinylidene chloride; vinylidene chloride / acrylonitrile copolymer, polyacrylonitrile, acrylonitrile / methacrylic acid alkyl ester copolymer, and other acrylonitrile-based (co) polymers; polymethyl methacrylate, etc. Acrylic (co) polymers such as polyvinyl chloride. Of these, acrylonitrile-based (co) polymers are particularly preferred. The resin material (resin composition) can contain additives such as a stabilizer, an ultraviolet absorber, an antioxidant, an antistatic agent, and a flame retardant.

  The shape of the thermally expandable microcapsule is spherical or elliptical spherical, and the particle diameter measured by thermomechanical analysis (TMA) or the like preferably gives an appropriate expansion coefficient and preferably gives a good heat insulating layer. It is 2 μm or more, more preferably 3 to 40 μm, still more preferably 3 to 30 μm.

  The composition for forming a heat insulating layer of the present invention may contain only one kind of the above heat-expandable microcapsules, or may contain two or more kinds.

  The composition for forming a heat insulation layer of the present invention may further contain other thermally expandable microcapsules having an expansion start temperature of less than 80 ° C or more than 150 ° C. In this case, the upper limit of the content of the other thermally expandable microcapsules is preferably 15 parts by mass when the total of the film-forming resin and the thermally expandable microcapsules is 100 parts by mass.

  The alcohol may be any of aliphatic alcohol, alicyclic alcohol and aromatic alcohol, and may be any of monool and polyol. In the present invention, the alcohol is preferably an alcohol that dissolves in water, and more preferably an aliphatic alcohol having 1 to 4 carbon atoms. Particularly preferred is isopropyl alcohol.

  The film-forming resin, heat-expandable microcapsule, alcohol and water contents contained in the heat-insulating layer-forming composition of the present invention are excellent in storage stability and smooth the heat-insulating layer with small variations in the size of the expanded capsule. Since it can form, when these sum is made into 100 mass%, it is 18-40 mass%, 5-22 mass%, 7-20 mass%, and 30-56 mass%, respectively, Preferably it is 20 -35 wt%, 8-20 wt%, 8-15 wt% and 38-55 wt%, more preferably 25-30 wt%, 9.5-16 wt%, 8.5-13.5 wt% and It is 42-53 mass%.

  The heat insulating layer-forming composition of the present invention is conventionally produced by mixing raw material components using a known mixer / disperser, that is, a planetary mixer, attritor, glenmill, kneader, roll, dissolver, or the like. Can do.

The composition for heat insulation layer formation of this invention is suitable for heat insulation layer formation to the surface of a base material. That is, after the composition is applied to the surface of the substrate 11 to form a coating film, the resulting coating film is heated to expand the thermally expandable microcapsules and form a resin film, thereby forming the film. The heat insulating material 1 which has the heat insulation layer 13 which consists of an expansion capsule containing resin film which contains the dispersed phase which consists of expansion capsules in the mother phase which consists of resin for resin can be manufactured (refer FIG. 1).
Another method of use is to form a coating film on the surface of a peelable sheet or the like, and then heat the resulting coating film to expand the volume of the thermally expandable microcapsules, thereby forming a matrix made of a film-forming resin. A single unit of an expanded capsule-containing resin film containing a dispersed phase composed of expanded capsules in the phase can be produced.

  As a method for producing a heat insulating material using the heat insulating layer forming composition of the present invention, in the present invention, a step of applying the heat insulating layer forming composition to the surface of the substrate (hereinafter referred to as “first step”). And heating the obtained coating film to evaporate alcohol and water, and forming a film while expanding the thermally expandable microcapsules contained in the coating film (hereinafter referred to as “second process”); Are sequentially provided.

The 1st process concerning this invention is a process of apply | coating the composition for heat insulation layer formation to the predetermined part of the surface of a base material.
The base material may contain either an organic material or an inorganic material, or may be a combination thereof. In the present invention, paper, resin film, resin molded body, inorganic material molded body and the like are preferably used.

In the first step, the method for applying the composition to the substrate is not particularly limited. Usually, coating (dip coating, bar coating, roll coating, gravure coating, curtain coating, kiss coating, etc.), spray (airless spray, air spray, etc.) It is appropriately selected from printing (gravure printing, screen printing, etc.).
The thickness of the coating film suitable for forming a film having excellent surface appearance and excellent heat insulation is usually 20 μm or more, preferably 30 to 100 μm, more preferably 40 to 80 μm. As described above, the composition for forming a heat insulating layer of the present invention is excellent in storage stability, and is suppressed in problems such as precipitation of specific components such as thermally expandable microcapsules. The thermally expandable microcapsules to be distributed are uniformly distributed throughout.

The second step according to the present invention is a step of heating the coating film to evaporate alcohol and water and forming a film while thermally expanding the thermally expandable microcapsules contained in the coating film.
The method for heating the coating film is not particularly limited, and may be a method for exposing the coating film to a predetermined heating temperature condition, a method for heating the coating film from room temperature to a predetermined heating temperature, or the like. The predetermined heating temperature and the heating time are appropriately selected depending on the type of the film-forming resin, the expansion start temperature of the thermally expandable microcapsules, and the like. The heating temperature of a coating film is 100 degreeC or more normally, Preferably it is 120 to 150 degreeC. Moreover, the heating time of a coating film is 30 to 180 second normally, Preferably it is 45 to 120 second. By such heat treatment, the thermally expandable microcapsule is expanded, and an expanded capsule-containing resin film having a thickness of preferably 4 to 16 times, more preferably 7 to 14 times the thickness of the coating film is obtained. be able to. The thickness of the expanded capsule-containing resin film is preferably 200 to 1000 μm, more preferably 300 to 800 μm. The size (average diameter) of the expanded capsules contained in the expanded capsule-containing resin film is preferably 30 to 100 μm, more preferably 50 to 80 μm.

  Although the heat insulating material 1 having the structure shown in FIG. 1 can be manufactured by the second step, the thicker heat insulating layer may be formed by repeating the first step and the second step depending on the purpose and application. Moreover, it can be set as the heat insulating material which has various structures by providing another process. For example, a composite material (not shown) formed by forming a layer covering at least a part of the surface of the heat insulating layer 13 of the heat insulating material 1 shown in FIG.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples unless it exceeds the gist of the present invention.

1. The raw material of the composition for heat insulation layer formation The raw material used by the Example and the comparative example is as follows.

1-1. Film forming resin An alcohol aqueous solution, aqueous dispersion or aqueous solution containing the following resin components was used.
(1) Alcohol aqueous solution of polyurethane resin (A1)
A polyurethane resin “Yuriano W321” (trade name) manufactured by Arakawa Chemical Co., which contains 35% by mass of a polyurethane resin having a glass transition temperature of −60 ° C., 9% by mass of isopropyl alcohol and 56% by mass of water was used.
(2) Aqueous dispersion of polyurethane resin (A2)
A non-reactive polyurethane resin “Superflex E2000” (trade name) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. containing 50% by mass of a polyurethane resin having a glass transition temperature of −38 ° C. and 50% by mass of water was used.
(3) Acrylic resin aqueous solution (A3)
An aqueous solution containing 40% by mass of an acrylic resin having a glass transition temperature of 21 ° C. was used.

1-2. Thermally expandable microcapsule A thermally expandable microcapsule containing isobutane inside an outer shell made of acrylonitrile / methacrylate copolymer, having an expansion start temperature of 90 ° C. and a particle diameter of 3 to 30 μm (average diameter of 10 μm) Using.
1-3. Antifoaming agent A silicone compound was used.

2. Manufacture and evaluation of the composition for heat insulation layer formation According to Table 1, the composition for heat insulation layer formation was manufactured. And the heat insulation paper was manufactured using the composition for heat insulation layer formation, and a base paper.

Example 1
An alcohol aqueous solution (A1) of 78 parts by mass of polyurethane resin, 12 parts by mass of thermally expandable microcapsules, 0.05 parts by mass of an antifoaming agent, and 10 parts by mass of 20% isopropyl alcohol aqueous solution were mixed. The composition for heat insulation layer formation (S1) was obtained. This composition was allowed to stand at 25 ° C. for 24 hours, and the storage stability was evaluated. There is no separation, sedimentation or thickening, or there is separation or sedimentation, but if it is stirred, it becomes a good dispersion state `` ○ '', there is separation or sedimentation, and it does not return to the original state even when stirring, Or the thing which thickens or gelatinizes was made into "x".
Next, the composition is applied to a base paper having a thickness of 275 μm by a bar coating method (the thickness of the coating film: 50 μm), heated in the atmosphere at 140 ° C. for 60 to 90 seconds, and the coating film is dried. The thermally expandable microcapsule was expanded to obtain a heat insulating paper having a film (heat insulating layer) having a thickness of 445 to 505 μm (see FIG. 2). The obtained film was excellent in adhesion to the base paper.
Thereafter, the surface of the heat-insulating paper was observed with an electron microscope, and it was confirmed that the film contained expanded capsules having an average diameter calculated as n = 10 of 65 μm and had a good foamed state ( (See FIG. 3). And in order to evaluate heat insulation, the surface by the side of the heat insulation layer 23 of the said heat insulation paper 20 is bonded to the whole side surface of the polypropylene resin cup (commercially available product) 30 having an internal volume of 200 mL shown in FIG. A heat retaining cup 50 was produced (see FIG. 5). Next, hot water (93 ° C.) is poured into the heat retaining cup 50, and the temperature of the surface on the side of the base paper 21 at the moment when it reaches an amount corresponding to about 90% of the internal volume (about 180 mL) is measured with a radiation thermometer. As a result, it was 71.7 degreeC. In addition, when hot water (93 degreeC) was poured into the polypropylene resin cup 30 without sticking the heat insulating paper 20, and the temperature of the side surface was measured, it was 89.7 degreeC.

Examples 2-5 and Comparative Examples 1 and 2
The raw materials shown in Table 1 were mixed to produce the heat insulating layer forming compositions (S2) to (S7), and then heat insulating paper and a heat retaining cup were obtained in the same manner as in Example 1. Various evaluations were performed. The results are shown in Table 1.

  As is apparent from Table 1, the compositions of Examples 1 to 5 are excellent in storage stability. Moreover, sufficient heat insulation effect was able to be acquired. On the other hand, the compositions of Comparative Examples 1 and 2 were inferior in storage stability.

  In addition, in this invention, it can restrict to what is shown to said specific Example, It can be set as the Example variously changed within the range of this invention according to the objective and the use.

  According to the composition for forming a heat insulating layer of the present invention, a film excellent in heat insulating properties can be easily formed on the surface of a substrate. A heat insulating material made of a composite material obtained using the composition for forming a heat insulating layer of the present invention is excellent in a heat insulating effect with respect to a temperature in the range of −40 ° C. to 100 ° C., for example. It can be widely used in fields such as a heat insulation box, food (a heated beverage or a container for containing food), clothing, automobiles, and the like.

  1: heat insulating material, 11: base material, 13: heat insulating layer, 20: heat insulating paper, 21: base paper, 23: heat insulating layer, 30: resin cup, 31: resin container part, 50: heat retaining cup

Claims (5)

  The resin for forming a film, the thermally expandable microcapsule having an expansion start temperature of 80 ° C. to 150 ° C., alcohol, and water are 18 to 40% by mass and 5 to 22 respectively when the total of these is 100% by mass. A composition for forming a heat insulating layer, comprising: mass%, 7 to 20 mass%, and 30 to 56 mass%.   The composition for heat insulation layer formation according to claim 1 in which said resin for film formation contains polyurethane resin whose glass transition temperature is -70 ° C--50 ° C.   The composition for forming a heat insulation layer according to claim 1 or 2, wherein the thermally expandable microcapsules are obtained by encapsulating a liquid compound in an outer shell made of a thermoplastic resin material.   The composition for heat insulation layer formation as described in any one of Claims 1 thru | or 3 in which the said alcohol contains isopropyl alcohol. A method of manufacturing a heat insulating material,
A step of applying the heat insulating layer forming composition according to any one of claims 1 to 4 to the surface of the substrate, heating the obtained coating film to evaporate alcohol and water, A method for producing a heat insulating material, comprising sequentially forming a film while expanding the thermally expandable microcapsules contained in the coating film.