JP6212326B2 - Laminated structure and method for forming the same - Google Patents

Description

  The present invention relates to a novel laminated structure. The laminated structure of the present invention can protect the base material when the temperature rises due to a fire or the like.

  Conventionally, in a building structure, in order to protect the building from a fire, it is required to make a main part such as a pillar, a beam, a floor, and a wall a heat resistant structure. As one method for applying a heat resistant structure, there is a method in which a thermally foamable sheet is attached to a base material such as a main part via an adhesive (for example, Patent Document 1).

  The heat-foamable sheet is normally thin and light, and has the effect of exhibiting heat-resistant protection by foaming and carbonizing to form a heat-insulating layer when the temperature rises due to a fire or the like. Such a heat-foamable sheet can be usually constructed by sticking with an adhesive or the like, and does not require an extra space and has a feature that the thickness can be made uniform.

JP-A-8-60763

  However, in the structure obtained by the above method, there are cases where it is difficult to efficiently obtain sufficient adhesiveness, or where it is difficult to hold the heat insulating layer formed during heating. In such a case, there is a possibility that the desired heat-resistant protection performance due to the thermally foamable sheet may not be sufficiently exhibited.

  The present invention has been made in view of the above problems, and aims to efficiently obtain a laminated structure having a stable adhesive force, and to exhibit excellent heat protection properties by the laminated structure. .

  As a result of intensive studies to solve the above problems, the present inventors have conceived that the adhesive layer is made into a specific configuration when the heat-foamable sheet is attached to the substrate, and the present invention is completed. I reached.

That is, the present invention has the following characteristics.
1. A laminated structure in which an adhesive layer and a heat-foamable sheet are laminated to a base material surface,
The adhesive layer has a first adhesive layer in contact with the substrate surface and a second adhesive layer in contact with the thermally foamable sheet,
The total thickness of the adhesive layer is 10 to 1000 μm,
The ratio of the thickness of the first adhesive layer to the adhesive layer total thickness, Ri 0.1 / 1 to 0.7 / 1 der,
The adhesive layer includes a synthetic resin;
The synthetic resin has an acid value of 30 KOH mg / g or more and 100 KOH mg / g or less and a hydroxyl value of 20 KOH mg / g or more and less than 70 KOH mg / g, or
An acid value of 10 KOH mg / g or more and less than 30 KOH mg / g and a hydroxyl value of 70 KOH mg / g or more and 150 KOH mg / g or less,
A laminated structure satisfying any of the following conditions:
2. The thermally foamable sheet contains a synthetic resin, a flame retardant, a foaming agent, and a carbonizing agent. The laminated structure described.
3.1. Or 2. A method of forming a laminated structure according to,
A first adhesive layer is provided on the substrate surface, and a second adhesive layer is provided on the back surface of the thermally foamable sheet.
A method for forming a laminated structure, comprising: pressing a first adhesive layer on the substrate surface and a second adhesive layer on the back surface of the thermally foamable sheet.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated structure which has the stable adhesive force can be obtained efficiently. The laminated structure of the present invention has excellent adhesiveness during normal times, and exhibits excellent anti-drop-off and anti-slip-off properties when the temperature rises, thereby achieving heat-resistant protection of the substrate.

It is sectional drawing which shows an example of this invention laminated structure. It is a schematic diagram which shows an example of the formation method of a laminated structure. It is sectional drawing which shows an example of a lamination sheet.

1: Base material 2: First adhesive layer 3: Thermally foamable sheet 4: Second adhesive layer 5: Laminated sheet 6: Release sheet

  Hereinafter, modes for carrying out the present invention will be described.

  The laminated structure of the present invention is obtained by laminating an adhesive layer and a thermally foamable sheet on a substrate surface.

  As the base material, materials mainly constituting columns, beams, floors, walls, etc. of building structures can be mentioned. For example, H steel, steel round column, steel square column, mortar, concrete, silica Examples include calcium acid plates, gypsum boards, calcium carbonate foam plates, incombustible volcanic glassy multilayer plates, fiber reinforced cement plates, lightweight cement plates, and the like. The surface of such a substrate may be treated with a rust inhibitor, a rust preventive paint or the like.

  The adhesive layer of the present invention is used for adhering and fixing the heat-foamable sheet to the substrate, and includes a first adhesive layer in contact with the substrate surface and a second in contact with the heat-foamable sheet. It has an adhesive layer (FIG. 1). Such an adhesive layer is provided with a first adhesive layer on the substrate surface and a second adhesive layer on the back surface of the thermally foamable sheet, and the first adhesive layer on the substrate surface and the thermally foamable sheet. It can form by crimping | bonding with the 2nd adhesive material layer of the back surface of (FIG. 2).

  Specifically, a thermally foamable sheet (hereinafter also referred to as “laminated sheet”) having a second adhesive layer provided on the back surface is prepared. On the other hand, an adhesive is applied to the substrate to form a first adhesive layer on the substrate surface. What is necessary is just to affix the back surface (2nd adhesive material side) of a lamination sheet with respect to such a base material.

  In the present invention, the thickness of the entire adhesive layer is set to 10 to 1000 μm (preferably 30 to 800 μm, more preferably 40 to 600 μm), and the ratio of the thickness of the first adhesive layer to the total thickness of the adhesive layer {( The thickness of the first adhesive layer) / (the thickness of the entire adhesive layer); hereinafter also simply referred to as “thickness ratio”} is 0.1 / 1 to 0.7 / 1 (preferably 0.15 / 1 to 0.00). 5/1, more preferably 0.2 / 1 to 0.45 / 1). In the present invention, excellent adhesiveness can be obtained efficiently by making the adhesive layer have such a configuration. Such an effect is achieved by setting the first adhesive layer to the above thickness ratio, thereby suppressing the influence of environmental conditions (air temperature, humidity, etc.) during work, unevenness on the substrate surface, unevenness. Even when there is dirt or the like, it is presumed that the above-described thickness ratio is achieved by the fact that sufficient adhesiveness is obtained by the action of the first adhesive layer. In addition, the thickness of the whole adhesive material layer in this invention, the thickness of a 1st adhesive material layer, and the thickness of a 2nd adhesive material layer are all the thickness of the layer at the time of drying.

  If the thickness of the entire adhesive layer is too small, the adhesion may be insufficient. If the thickness of the entire adhesive layer is too large, the sheet is likely to be displaced or dropped when the temperature rises. On the other hand, if the thickness ratio is too smaller than the above value, the adhesion may be insufficient. If the thickness ratio is too larger than the above value, it may take time to develop adhesiveness depending on the environmental conditions during work, and it is difficult to obtain a stable adhesive force efficiently.

  Various adhesives can be used as the adhesive forming the adhesive layer. Examples of adhesives include rubber adhesives, acrylic adhesives, vinyl chloride adhesives, vinyl acetate adhesives, epoxy adhesives, urethane adhesives, alkyd adhesives, melamine adhesives, and silicones. System adhesives and the like. The adhesive material in the present invention includes an adhesive material.

  As the adhesive in the present invention, either the following adhesive (a) or adhesive (b) is particularly suitable. By using such an adhesive, it is possible to further enhance the effects such as adhesion at normal times, drop-off prevention at temperature rise, and slip-off prevention.

  The adhesive (a) has an acid value of 30 KOH mg / g to 100 KOH mg / g (preferably 35 KOH mg / g to 90 KOH mg / g), and a hydroxyl value of 20 KOH mg / g to 70 KOH mg / g (preferably 25 KOH mg / g to 60 KOH mg). / G or less).

  The adhesive (b) has an acid value of 10 KOH mg / g or more and less than 30 KOH mg / g (preferably 15 KOH mg / g or more and 25 KOH mg / g or less), and a hydroxyl value of 70 KOH mg / g or more and 150 KOH mg / g or less (preferably 80 KOH mg / g or more and 130 KOH mg or less). / G or less).

  In addition, the acid value said here is a value (KOHmg / g) represented by the number of mg of potassium hydroxide equimolar to the acid group contained in 1 g of solid content, and the hydroxyl value is 1 g of solid content. It is a value (KOHmg / g) represented by the number of mg of potassium hydroxide equimolar to the hydroxyl group contained.

  The glass transition temperature of the synthetic resin is not particularly limited, but is preferably about −60 ° C. or higher and 30 ° C. or lower, more preferably −40 ° C. or higher and 0 ° C. or lower, and further preferably −35 ° C. or higher and −5 ° C. or lower. . When the glass transition temperature is in such a region, the effect of the present invention can be stably obtained. In addition, a glass transition temperature is a value calculated | required from the calculation formula of FOX.

  The synthetic resin in the adhesives (a) and (b) is not particularly limited as long as it has the above acid value and hydroxyl value, and examples thereof include acrylic resins, vinyl chloride resins, and vinyl acetate resins. , Epoxy resin, urethane resin, alkyd resin, melamine resin, silicone resin and the like. Examples of the form of these synthetic resins include a water dispersion type, a water soluble type, a solvent type, and a solventless type. In the present invention, a water-dispersed acrylic resin (acrylic resin emulsion) is particularly suitable.

  The synthetic resin having such specific acid value and specific hydroxyl value is, for example, one or more monomers selected from carboxyl group-containing monomers and one or more single monomers selected from hydroxyl group-containing monomers. And a monomer mixture containing other monomers as required can be obtained by copolymerization by a known method. As the polymerization method, a known method may be employed, and soap-free emulsion polymerization, feed emulsion polymerization, seed emulsion polymerization, etc. may be employed in addition to ordinary emulsion polymerization. Moreover, an emulsifier, an initiator, a dispersant, a polymerization inhibitor, a polymerization inhibitor, a buffering agent, a chain transfer agent and the like can also be used during polymerization. A reactive emulsifier can also be used as an emulsifier.

  Examples of the carboxyl group-containing monomer include (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, etc. Among them, (meth) acrylic acid is particularly preferable.

  The ratio of the carboxyl group-containing monomer in the synthetic resin of the adhesive (a) is preferably 5% by weight or more and 18% by weight or less, more preferably 5.5% by weight or more and 15% by weight or less with respect to the total amount of monomers. is there. The ratio of the carboxyl group-containing monomer in the synthetic resin of the adhesive (b) is preferably 1% by weight or more and less than 5% by weight, more preferably 2% by weight or more and 4% by weight or less based on the total amount of the monomers.

  Examples of the hydroxyl group-containing monomer include primary hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2- Secondary hydroxyl group-containing monomers such as hydroxypropyl (meth) acrylate and 2-hydroxybutyl (meth) acrylate, tertiary hydroxyl group-containing monomers such as 2-hydroxy-2-methylpropyl (meth) acrylate, Glycerol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol (meth) acrylate, caprolactone-modified (meth) acrylic acid ester, N-hydroxyethylacrylamide and the like. In the present invention, it is preferable to include a primary hydroxyl group-containing monomer and / or a tertiary hydroxyl group-containing monomer as the hydroxyl group-containing monomer in terms of improving adhesion and the like. More preferably, it contains a containing monomer and a tertiary hydroxyl group-containing monomer.

  The ratio of the hydroxyl group-containing monomer in the synthetic resin of the adhesive (a) is preferably 5% by weight or more and less than 16% by weight, more preferably 5.5% by weight or more and 15% by weight or less with respect to the total amount of monomers. is there. The ratio of the hydroxyl group-containing monomer in the synthetic resin of the adhesive (b) is preferably 16% by weight or more and 35% by weight or less, more preferably 17% by weight or more and 32% by weight or less with respect to the total amount of monomers.

Other monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl ( Alkyl group-containing (meth) acrylic monomers such as (meth) acrylate,
Amino group-containing (meth) acrylic monomers such as dimethylaminoethyl (meth) acrylate and dimethylaminopropyl (meth) acrylate,
Amide-containing (meth) acrylic monomers such as (meth) acrylamide and ethyl (meth) acrylamide,
Nitrile group-containing (meth) acrylic monomers such as acrylonitrile,
Epoxy group-containing (meth) acrylic monomers such as glycidyl (meth) acrylate,
γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, etc. Hydrolyzable silyl group-containing vinyl monomers,
Fluorine-containing (meth) acrylic monomers such as trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate,
Fluoroolefins such as vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, pentafluoroethylene, hexafluoropropylene,
Aromatic hydrocarbon vinyl monomers such as styrene, methylstyrene, chlorostyrene, vinyltoluene,
Sulfonic acid-containing vinyl monomers such as styrene sulfonic acid and vinyl sulfonic acid,
Chlorine-containing monomers such as vinyl chloride, vinylidene chloride, chloroprene,
Α-olefins such as ethylene, propylene and isobutylene,
Vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate,
Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether,
Allyl ethers such as ethyl allyl ether and butyl allyl ether,
These can be used alone or in combination of two or more.

  The adhesive used in the present invention may contain known additives in addition to the synthetic resin. Additives include, for example, fillers, colorants, diluents, tackifiers, thickeners, dispersants, antifoaming agents, antiseptics, antifungal agents, antialgae agents, UV absorbers, and light stabilizers. Agents and the like.

  As the thermally foamable sheet in the present invention, a sheet that foams and carbonizes when the temperature rises to form a heat insulating layer can be used. Suitable thermal foamable sheets include, for example, those containing synthetic resins, flame retardants, foaming agents, carbonizing agents, and the like.

  As the synthetic resin in the thermally foamable sheet, a thermoplastic resin is preferably used. Examples of such thermoplastic resins include polyethylene resins, polypropylene resins, polybutene resins, polypentene resins, polystyrene resins, polycarbonate resins, acrylic resins, polyphenylene ether resins, polyamide resins, polyvinyl chloride resins, phenol resins, polyurethane resins, Chloroprene resin, polybutadiene, polyisobutylene, nitrile rubber, butyl rubber, vinyl toluene-butadiene copolymer, vinyl toluene-acrylic acid ester copolymer, vinyl toluene-methacrylic acid ester copolymer, styrene-butadiene copolymer, ethylene- Examples thereof include a methacrylic acid ester copolymer and an ethylene-vinyl acetate copolymer.

  In general, a flame retardant exhibits at least one effect such as a dehydration cooling effect, an incombustible gas generation effect, and a binder carbonization promoting effect in a fire, and has an action of preventing or suppressing combustion of a resin component. Examples of the flame retardant include tricresyl phosphate, diphenyl cresyl phosphate, diphenyl octyl phosphate, tri (β-chloroethyl) phosphate, tributyl phosphate, tri (dichloropropyl) phosphate, triphenyl phosphate, triphenyl Organic phosphorus such as (dibromopropyl) phosphate, chlorophosphonate, bromophosphonate, diethyl-N, N-bis (2-hydroxyethyl) aminomethyl phosphate, di (polyoxyethylene) hydroxymethyl phosphonate Compounds: Chlorinated polyphenyl, chlorinated polyethylene, diphenyl chloride, triphenyl chloride, pentachloride fatty acid ester, perchloropentacyclodecane, chlorinated naphthalene, tetrachlorophthalic anhydride, etc. Compounds; antimony compounds such as antimony trioxide and antimony pentachloride; phosphorus compounds such as phosphorus trichloride, phosphorus pentachloride, ammonium phosphate and ammonium polyphosphate; and other inorganic compounds such as zinc borate and sodium borate . These can be used alone or in combination of two or more. In the present invention, ammonium polyphosphate is particularly preferable. In the case of using ammonium polyphosphate, the dehydration cooling effect and the incombustible gas generation effect can be more effectively exhibited, so that the flame retardancy effect is high and the content of the foaming agent can be reduced.

  In general, the blowing agent generates a non-flammable gas in the event of a fire, foams the carbonized resin component and the carbonizing agent, and forms a carbonized heat insulation layer having pores. Examples of the foaming agent include nitrogen-containing compounds such as melamine and derivatives thereof, dicyandiamide and derivatives thereof, azodicarbonamide, urea and thiourea. Moreover, these can be used individually or in mixture of 2 or more types. Among these, melamine, dicyandiamide, azodicarbonamide and the like are preferable because they are excellent in generating efficiency of nonflammable gas.

  The carbonizing agent generally has a function of forming a carbonized heat insulating layer having a thickness superior in heat insulating properties by dehydrating and carbonizing itself with the carbonization of the resin component due to a fire. Examples of the carbonizing agent include starch, casein and the like, in addition to polyhydric alcohols such as dipentaerythritol, pentaerythritol, and trimethylolpropane. These can be used alone or in combination of two or more.

  The composition ratio of each component in the thermally foamable sheet is 200 parts by weight or more and 600 parts by weight or less (preferably 250 parts by weight or more and 500 parts by weight or less) of the flame retardant with respect to 100 parts by weight of the solid content of the resin component. It is preferable that they are 10 parts by weight or more and 200 parts by weight or less (preferably 20 parts by weight or more and 150 parts by weight or less), and 10 parts by weight or more and 200 parts by weight or less (preferably 30 parts by weight or more and 150 parts by weight or less).

  In addition to the above-mentioned components, the heat-foamable sheet is also a filler, pigment, fiber, wetting agent, plasticizer, lubricant, antiseptic, antifungal agent, antialgae, antibacterial agent, thickener, leveling agent, dispersant. Further, it may contain an antifoaming agent, a crosslinking agent, an ultraviolet absorber, an antioxidant, a catalyst and the like.

  Among these, the filler generally has an effect of improving the strength of the carbonized heat insulating layer and increasing the heat resistance protection. The filler is not particularly limited as long as it has such an action, and the same filler as that in a known thermally foamable sheet can be used. Examples thereof include silicates such as talc; carbonates such as calcium carbonate and sodium carbonate; metal oxides such as aluminum oxide, titanium dioxide and zinc oxide; natural minerals such as clay, clay, shirasu and mica. These can be used alone or in combination of two or more. Of these fillers, titanium dioxide is more preferred.

  As the pigment, general color pigments (organic pigments / inorganic pigments) can be used. In the present invention, inorganic pigments such as bengara, yellow lead, yellow iron oxide, titanium yellow, chrome green, ultramarine blue, cobalt blue and cadmium red are particularly preferable. Further, in order to further improve the heat resistance protection, expandable graphite, unexpanded vermiculite, etc. may be blended.

  The thermally foamable sheet used in the present invention can be produced by a known method. For example, a method in which an appropriate solvent is added to a composition containing an appropriate amount of the above-described synthetic resin, flame retardant, foaming agent, carbonizing agent, etc., if necessary, poured into a mold, and demolded after drying; A method of winding the composition after being applied to a release paper by a warming coater; a method of processing the composition kneaded by a kneader into a sheet shape by an extrusion molding machine; and the composition kneaded by a kneader between a pair of rolls A method of supplying and processing into a sheet; a method of forming the composition into a pellet and then processing into a sheet with an extrusion molding machine; a calendar comprising a plurality of heat rolls of the composition kneaded by a Banbury mixer, a mixing roll, or the like And a method of rolling and processing into a sheet.

  A reinforcing sheet can be laminated on the thermally foamable sheet. Examples of the reinforcing sheet include woven fabric, non-woven fabric, mesh, and composites thereof. The reinforcing sheet is desirably laminated at least on the back side of the thermally foamable sheet. A heat-foamable sheet having such a reinforcing sheet is suitable in terms of improving effects such as adhesion, drop-off prevention, and slip-off prevention.

  The thickness of the thermally foamable sheet is not particularly limited, but is preferably 0.2 mm or more and 10 mm or less, more preferably 0.5 mm or more and 6 mm or less.

  In the present invention, a laminated sheet having a thermally foamable sheet and a second adhesive layer can be used. Such a laminated sheet can be obtained by forming the second adhesive layer on the back surface of the thermally foamable sheet with the adhesive. Furthermore, the surface of the second adhesive layer can be covered with a release sheet. FIG. 3 shows an example of a laminated sheet having a second adhesive layer and a releasable sheet on the back surface of the thermally foamable sheet. By using such a laminated sheet, work efficiency can be improved.

  The releasable sheet protects the second adhesive layer during storage or transportation of the thermally foamable sheet, and can be easily peeled from the second adhesive layer when using the thermally foamable sheet. . As such a release sheet, a known sheet can be used, for example, a paper or film coated or impregnated with a release agent such as silicon, wax, fluorine resin, or the like, or does not contain the release agent. Examples thereof include synthetic resin films such as polypropylene and polyethylene having releasability.

  The method for producing the laminated sheet is not particularly limited, but for the laminated sheet in FIG. 3, for example, a method of applying an adhesive on one surface of the thermally foamable sheet and laminating a release sheet thereon, or a separating sheet. Examples thereof include a method of applying an adhesive on the mold sheet and laminating a thermally foamable sheet thereon. In such a laminated sheet, it is desirable that the adhesive is dried after application. When the adhesive is dried, it can be heated. What is necessary is just to set suitably the application amount of an adhesive material so that a 2nd adhesive material layer may become predetermined | prescribed thickness.

  In the present invention, an adhesive may be applied to the substrate, a first adhesive layer may be formed on the substrate surface, and a laminated sheet may be attached to the substrate. When the laminated sheet has a releasable sheet, the releasable sheet may be peeled off and the second adhesive layer may be exposed and attached.

  When applying the adhesive to the substrate, for example, a tool such as a brush, a roller, a trowel, a spatula, or a spray can be used. What is necessary is just to set suitably the application amount of an adhesive material so that a 1st adhesive material layer may become predetermined | prescribed thickness.

  In the present invention, after the adhesive (first adhesive layer) on the surface of the base material is dried, it is desirable that the laminated sheet is attached and pressure-bonded to the first adhesive layer so that the second adhesive layer is in contact therewith. . When pressing, a pressing tool such as a roller or a trowel can be used as necessary.

  In the present invention, a decorative layer can be formed on the surface of the thermally foamable sheet. The decorative layer may be formed by a known method. For example, various paints can be applied, or a decorative film, a decorative sheet, or the like can be laminated. The decorative layer may be a laminate of a plurality of materials.

  Hereinafter, an Example is shown and the characteristic of this invention is clarified more.

(Manufacture of adhesives)
The following synthetic resin emulsions 1 to 18 were used as adhesives 1 to 18, respectively.

(Production of synthetic resin emulsion 1)
A reaction vessel was charged with 104.4 parts by weight of deionized water, and the temperature was raised to 80 ° C. while stirring and purging with nitrogen. To this, separately prepared emulsion monomer (89.6 parts by weight of butyl acrylate, 5.2 parts by weight of methacrylic acid, 2 parts by weight of an aqueous solution in which 3.1 parts by weight of sodium dodecyl sulfate was dissolved in 42.2 parts by weight of deionized water) -Emulsified and dispersed with 5.2 parts by weight of hydroxyethyl methacrylate) and an aqueous initiator solution (aqueous solution in which 0.4 parts by weight of ammonium persulfate was dissolved in 7.6 parts by weight of deionized water), each over 3 hours. (See Table 1).
After completion of dropping, the mixture was aged for 3 hours, cooled to 30 ° C., and then added with aqueous ammonia to adjust the pH to 8 to obtain a synthetic resin emulsion 1. The resin solid content of the synthetic resin emulsion 1 was 40% by weight, Tg was −36 ° C., the acid value was 33 KOH mg / g, and the hydroxyl value was 22 KOH mg / g.

(Production of synthetic resin emulsions 2 to 18)
Synthetic resin emulsions 2 to 18 were produced by the same production method as synthetic resin emulsion 1 except that the monomer composition shown in Table 1 was followed.

(Manufacture of thermally foamable sheet 1)
A raw material mixture containing 100 parts by weight of an acrylic resin, 75 parts by weight of melamine, 75 parts by weight of dipentaerythritol, 370 parts by weight of ammonium polyphosphate and 105 parts by weight of titanium oxide is sufficiently kneaded using a kneader, and then sheeted by an extruder. To form a thermally foamable sheet 1 having a thickness of 1 mm.

(Manufacture of thermally foamable sheet 2)
A raw material mixture containing 100 parts by weight of ethylene-vinyl acetate resin, 75 parts by weight of melamine, 75 parts by weight of dipentaerythritol, 370 parts by weight of ammonium polyphosphate and 105 parts by weight of titanium oxide is sufficiently kneaded using a kneader, and then extruded. It processed into the sheet form with the machine, and produced the heat foamable sheet 2 with a film thickness of 1 mm.

Example 1
1. Adhesion test 1
Adhesive 1 was applied to one half (25 mm × 25 mm) of thermal foamable sheet 1 (25 mm × 50 mm) and dried at 23 ° C. for 3 hours to form a second adhesive layer having a dry thickness of 70 μm. On the other hand, the adhesive 1 was applied to one side of a steel plate (150 mm × 70 mm × 1.6 mm) and dried at 23 ° C. for 3 hours to form a first adhesive layer having a dry thickness of 30 μm.
Next, the adhesive-coated surface (second adhesive layer) of the heat-foamable sheet 1 and the adhesive-coated surface (first adhesive layer) of the steel plate were bonded together by pressure bonding to obtain a test specimen. (In addition, this test body is the aspect which the half surface of the thermally foamable sheet 1 is not adhere | attached on a steel plate (it has a non-adhesion part)). In the test body of Example 1, the thickness of the entire adhesive layer is 100 μm, and the thickness ratio is 0.3 / 1.
In the adhesion test 1, the test specimen is placed horizontally so that the heat-foamable sheet 1 is on the lower side, the non-adhesive portion of the heat-foamable sheet 1 is bent at 90 °, and the heat-foamable sheet 1 is bent. A weight of 200 g was suspended from the tip of the steel sheet, and the time until the thermally foamable sheet 1 was peeled off from the steel plate was measured. Evaluation was performed in the following five stages. The results are shown in Table 2.
A: 2 hours or more B: 1 hour or more and less than 2 hours C: 30 minutes or more and less than 1 hour D: 15 minutes or more and less than 30 minutes E: Less than 15 minutes

2. Adhesion test 2
Adhesive 1 was applied to one half (25 mm × 25 mm) of thermal foamable sheet 1 (25 mm × 50 mm) and dried at 23 ° C. for 3 hours to form a second adhesive layer having a dry thickness of 70 μm. On the other hand, the adhesive 1 was applied to one side of a steel plate (150 mm × 70 mm × 1.6 mm) and dried at 5 ° C. for 1 hour to form a first adhesive layer having a dry thickness of 30 μm. Thereafter, test specimens were produced in the same manner as in the above-mentioned adhesion test 1, and the adhesion test was performed. The results are shown in Table 2.

3. Dropout test 1
The adhesive 1 was applied to the entire surface of one side of the thermally foamable sheet 1 (70 mm × 70 mm), and dried at 23 ° C. for 3 hours to form a second adhesive layer having a dry thickness of 70 μm. On the other hand, the adhesive 1 was applied to one side of a steel plate (150 mm × 70 mm × 1.6 mm) and dried at 5 ° C. for 1 hour to form a first adhesive layer having a dry thickness of 30 μm.
Next, the adhesive-coated surface of the thermally foamable sheet 1 and the adhesive-coated surface of the steel plate were bonded together by pressure bonding to obtain a test body.
In the drop-off test 1, the heat-foamable sheet 1 is installed horizontally so that it is on the lower side, a heater (heater temperature 680 ° C.) is installed at a position 25 mm above the test body, and the test body is heated with the heater. The interface temperature between the steel plate and the heat-foamable sheet 1 when the heat-foamable sheet 1 dropped from the steel plate was measured. Evaluation was performed in the following four stages. The results are shown in Table 2.
◎: Drop-off temperature 320 ° C or higher ○: Drop-off temperature 300 ° C or higher and lower than 320 ° C △: Drop-off temperature 280 or higher and lower than 300 ° C ×: Drop-off temperature 280 ° C or lower

4). Dropout test 2
A specimen was obtained in the same manner as in the drop test 1.
In the drop-off test 2, the test body was installed vertically, and a propane gas burner was installed at a position 50 cm laterally from the test body (one surface side of the thermally foamable sheet).
In the drop-off test 2, the specimen was heated for 1 minute with a propane gas burner, and the state of the thermally foamable sheet 1 was evaluated. Evaluation was performed in the following three stages. The results are shown in Table 2.
○: Not dropped △: Partially dropped ×: Dropped

(Examples 2 to 24, Comparative Examples 1 to 4)
In Examples 2 to 24 and Comparative Examples 1 to 4, the type of adhesive used, the overall thickness and the thickness ratio, and the type of thermally foamable sheet used were as shown in Table 2. Other than that, by the same method as Example 1, the test body was produced and each test was done. The results are shown in Table 2.

Claims (3)

A laminated structure in which an adhesive layer and a heat-foamable sheet are laminated to a base material surface,
The adhesive layer has a first adhesive layer in contact with the substrate surface and a second adhesive layer in contact with the thermally foamable sheet,
The total thickness of the adhesive layer is 10 to 1000 μm,
The ratio of the thickness of the first adhesive layer to the adhesive layer total thickness, Ri 0.1 / 1 to 0.7 / 1 der,
The adhesive layer includes a synthetic resin;
The synthetic resin has an acid value of 30 KOH mg / g or more and 100 KOH mg / g or less and a hydroxyl value of 20 KOH mg / g or more and less than 70 KOH mg / g, or
An acid value of 10 KOH mg / g or more and less than 30 KOH mg / g and a hydroxyl value of 70 KOH mg / g or more and 150 KOH mg / g or less,
A laminated structure satisfying any of the following conditions:   The laminated structure according to claim 1, wherein the thermally foamable sheet contains a synthetic resin, a flame retardant, a foaming agent, and a carbonizing agent. A method for forming the laminated structure according to claim 1, comprising:
A first adhesive layer is provided on the substrate surface, and a second adhesive layer is provided on the back surface of the thermally foamable sheet.
A method for forming a laminated structure, comprising: pressing a first adhesive layer on the substrate surface and a second adhesive layer on the back surface of the thermally foamable sheet.

Images