Laminate and head-mounted article

Abstract

Provided is a laminate having good shock absorption, air permeability, and detachability of a hook-and-loop fastener. This laminate (1) is obtained by adhering a first polyurethane foam layer (3) and a second polyurethane foam layer (5). The number of cells of the first polyurethane foam layer (3) as based on JIS K 6400-1:2004, Appendix A, is 6-40 cells / 25 mm; the resilience of the second polyurethane foam layer (5) as based on JIS K 6400-3:2011 is 15% or less; and when a measurement test piece of the laminate (1), which is obtained by adhering the first polyurethane foam layer (3) having a thickness of 3.0±1.0 mm and the second polyurethane foam layer (5) having a thickness of 9.5±1.0 mm, is measured in accordance with the A method of JIS K 6400-7:2012, the degree of air flow is 25 cm3 / cm2·s or more.

Description

Laminated body and head-mounted device

[0001] This disclosure relates to laminates and head-mounted devices.

[0002] A laminate is disclosed in which urethane foams with different functions are bonded together (see, for example, Patent Document 1).

[0003] Japanese Patent Publication No. 2000-041794

[0004] However, this laminate is a mattress, and cushioning, breathability, and ease of attaching and detaching the hook-and-loop fasteners have not been considered.

[0005] This disclosure is made in view of the above circumstances and aims to provide a laminate with good cushioning, breathability, and ease of attachment and detachment of hook-and-loop fasteners. This disclosure can be realized in the following forms.

[0006] [1] A laminate in which a first polyurethane foam layer and a second polyurethane foam layer are bonded together, wherein the number of cells in the first polyurethane foam layer according to JIS K6400-1:2004 Annex A is 6 cells / 25 mm or more and 40 cells / 25 mm or less, and the rebound elasticity of the second polyurethane foam layer according to JIS K 6400-3:2011 is 15% or less, and when a test specimen of this laminate, which is bonded together with the first polyurethane foam layer having a thickness of 3.0 ± 1.0 mm and the second polyurethane foam layer having a thickness of 9.5 ± 1.0 mm, is measured according to JIS K6400-7 Method A:2012, the air permeability is 25 cm ３ / cm ２ - A laminate that is s or greater.

[0007] According to this disclosure, a laminate with good cushioning, breathability, and ease of attachment and detachment of hook-and-loop fasteners can be obtained.

[0008] This is a cross-sectional view of a laminate according to one embodiment. This is an explanatory diagram showing an example of a head-mounted device. This is a cross-sectional view of Figure 2. This is a graph showing the results of a wash-drying test.

[0009] Herein are preferred examples of the present disclosure. [2] The laminate according to [1], wherein the first polyurethane foam layer is defilmed. [3] The laminate according to [1] or [2], wherein the adhesion between the first polyurethane foam layer and the second polyurethane foam layer is performed using a compound having an NCO terminus. [4] The laminate according to any one of [1] to [3], wherein the surface of the first polyurethane foam layer is an attachment portion for a hook-and-loop fastener, and the hook-and-loop fastener is detachably attached to the surface by hooking onto the polyurethane foam skeleton exposed on the surface. [5] A head attachment comprising the laminate according to any one of [1] to [4].

[0010] The disclosure is described in detail below. In this specification, when a numerical range is indicated using "-", it includes both the lower and upper limits unless otherwise specified. For example, "10-20" includes both the lower limit "10" and the upper limit "20". That is, "10-20" means the same as "10 or more and 20 or less". Furthermore, in this specification, the upper and lower limits of each numerical range can be combined in any way. ３ / cm ２ ・s" ml / cm ２ / s" "cm ３ / cm ２ The unit " / s" is the same in all cases, only the notation differs.

[0011] 1. Laminate 1 The laminate 1 of this embodiment is formed by bonding a first polyurethane foam layer 3 and a second polyurethane foam layer 5 (see Figure 1). The number of cells in the first polyurethane foam layer 3, according to JIS K6400-1:2004 Annex A, is 6 cells / 25 mm or more and 40 cells / 25 mm or less. The rebound elasticity of the second polyurethane foam layer 5, according to JIS K 6400-3:2011, is 15% or less. When a test piece of this laminate 1, formed by bonding a first polyurethane foam layer 3 with a thickness of 3.0 ± 1.0 mm and a second polyurethane foam layer 5 with a thickness of 9.5 ± 1.0 mm, was measured according to JIS K6400-7 Method A:2012, the air permeability was 25 cm３ / cm ２ ・s or more.

[0012] 2. Physical properties of the first polyurethane foam layer 3 (1) Cell count The cell count of the first polyurethane foam layer 3 is such that the number of cells measured based on the procedure described in the cell counting procedure of Annex A of JIS K6400-1:2004 is 6 cells / 25 mm or more from the viewpoints of ensuring good air permeability and adhesion retention of the surface fastener, preferably 10 cells / 25 mm or more, and more preferably 13 cells / 25 mm or more. From the viewpoint of good detachable property of the surface fastener 11, the above cell count is 40 cells / 25 mm or less, preferably 35 cells / 25 mm or less, and more preferably 30 cells / 25 mm or less. From these viewpoints, the above cell count is 6 cells / 25 mm or more and 40 cells / 25 mm or less, preferably 10 cells / 25 mm or more and 35 cells / 25 mm or less, and more preferably 13 cells / 25 mm or more and 30 cells / 25 mm or less. In the present disclosure, a cell means a pore portion in the foam. The cell count is the number of cells per 25 mm of the sample piece counted based on the above JIS K6400-1:2004. Here, the control of the cell count of the first polyurethane foam layer 3 will be described. The cell count can be controlled by the type and blending ratio of the polyol, the type and blending amount of the foam stabilizer, the addition amount of the foaming agent, etc. (2) Air permeability (air permeability degree) The air permeability (JIS K6400-7 Method A: 2012) of the first polyurethane foam layer 3 is preferably 25 cm ３ / cm ２ ・s or more from the viewpoint of obtaining a laminate 1 with good air permeability, more preferably 50 cm ３ / cm ２ ・s or more, and still more preferably 100 cm ３ / cm ２ ・s or more. Incidentally, the air permeability is usually 700 cm ３ / cm ２ ・s or less. Here, the control of the air permeability will be described. The air permeability can be controlled by the blending ratio of each polyol, the type and blending amount of the catalyst, the type and blending amount of the foam stabilizer, the film-forming treatment, etc.

[0013] (3) Apparent density The apparent density (JIS K7222:2005) of the first polyurethane foam layer 3 is preferably 15 kg / m ３ or more and 60 kg / m ３ or less from the viewpoint of reducing the weight of the laminate, more preferably 20 kg / m ３ or more and 50 kg / m ３ or less, and still more preferably 25 kg / m ３ or more and 40 kg / m ３ or less. Here, the control of the apparent density will be described. The apparent density can be controlled by the addition amount of the foaming agent.

[0014] 3. Physical properties of the second polyurethane foam layer 5 (1) Resilience The resilience (conforming to JIS K 6400-3:2011) of the second polyurethane foam layer 5 is preferably 15% or less, more preferably 12% or less, and still more preferably 10% or less from the viewpoint of ensuring sufficient cushioning properties of the laminate 1. The lower limit value of the resilience of the second polyurethane foam layer 5 is not particularly limited, but is usually 1% or more. Here, the control of the resilience will be described. The resilience can be controlled by the molecular weight between crosslinking points of the resin (polyurethane foam) (the magnitude of the spring component of the resin).

[0015] (2) Air permeability The air permeability (JIS K6400-7 Method A:2012) of the second polyurethane foam layer 5 is preferably 10 cm ３ / cm ２ ·s or more, more preferably 20 cm ３ / cm ２ ·s or more, and still more preferably 25 cm ３ / cm ２ ·s or more from the viewpoint of obtaining a laminate 1 with good air permeability. In addition, the air permeability is usually 700 cm ３ / cm ２ ·s or less. Here, the control of the air permeability will be described. The air permeability can be controlled by the blending ratio of each polyol, the type and blending amount of the catalyst, the type and blending amount of the foam stabilizer, the surface treatment, etc.

[0016] (3) Apparent density The apparent density (JIS K7222:2005) of the second polyurethane foam layer 5 is 30 kg / m３ 200 kg / m or less is preferable, ３ and 40 kg / m or more is more preferable, ３ 150 kg / m or less is more preferable, ３ and 60 kg / m or more is even more preferable, ３ 110 kg / m or less is even more preferable. Here, the control of apparent density will be described. The apparent density can be controlled by the addition amount of the foaming agent. ３

[0017] 4. Physical properties of the laminate 1 and thickness of each layer (1) When a test piece for measurement of the present laminate 1 formed by bonding a first polyurethane foam layer 3 having a thickness of 3.0 ± 1.0 mm and a second polyurethane foam layer 5 having a thickness of 9.5 ± 1.0 mm is measured according to JIS K6400-7 A method: 2012, from the viewpoint of obtaining a laminate 1 with good air permeability, the air permeability is 25 cm ３ / cm ２ ·s or more, and 40 cm ３ / cm ２ ·s or more is preferable, and 50 cm ３ / cm ２ ·s or more is more preferable. Incidentally, the air permeability is usually 700 cm ３ / cm ２ ·s or less.

[0018] ​(2) Thickness of each layer The thickness of the first polyurethane foam layer 3 in the laminate 1 is not particularly limited. From the viewpoint of ensuring good attachment and detachment of the hook and loop fastener 11, the thickness of the first polyurethane foam layer 3 is preferably 1 mm or more, more preferably 1.5 mm or more, and even more preferably 2 mm or more. From the viewpoint of reducing the weight of the laminate, the thickness of the first polyurethane foam layer 3 is preferably 10 mm or less, more preferably 6 mm or less, and even more preferably 4 mm or less. From these viewpoints, the thickness of the first polyurethane foam layer 3 is preferably 1 mm or more and 10 mm or less, more preferably 1.5 mm or more and 6 mm or less, and even more preferably 2 mm or more and 4 mm or less. The thickness of the second polyurethane foam layer 5 in the laminate 1 is not particularly limited. From the viewpoint of ensuring sufficient cushioning of the laminate 1, the thickness of the second polyurethane foam layer 5 is preferably 2 mm or more, more preferably 2.5 mm or more, and even more preferably 3 mm or more. From the viewpoint of ensuring sufficient breathability of the laminate 1, the thickness of the second polyurethane foam layer 5 is preferably 20 mm or less, more preferably 15 mm or less, and even more preferably 13 mm or less. From these viewpoints, the thickness of the second polyurethane foam layer 5 is preferably 2 mm or more and 20 mm or less, more preferably 2.5 mm or more and 15 mm or less, and even more preferably 3 mm or more and 13 mm or less.

[0019] 5. Formation of the First Polyurethane Foam Layer 3 and the Second Polyurethane Foam Layer 5 The first polyurethane foam layer 3 is obtained from a first polyurethane foam composition containing a polyol component, polyisocyanate, and a blowing agent. The first polyurethane foam composition is foamed by mixing and stirring, causing the polyol component and polyisocyanate to react and form the first polyurethane foam. The second polyurethane foam layer 5 is obtained from a second polyurethane foam composition containing a polyol component, polyisocyanate, and a blowing agent. The second polyurethane foam composition is foamed by mixing and stirring, causing the polyol component and polyisocyanate to react and form the second polyurethane foam. The raw materials used for the first polyurethane foam layer 3 and the second polyurethane foam layer 5 will be described below. The raw materials for the first polyurethane foam layer 3 are appropriately selected to match the physical properties of the first polyurethane foam layer 3 as described above. The raw materials for the second polyurethane foam layer 5 are appropriately selected to match the physical properties of the second polyurethane foam layer 5 as described above.

[0020] (1) Polyol component The polyol component includes polyols, which are compounds having two or more hydroxyl groups in a single molecule. The polyol is not particularly limited. Various polyols may be used individually or in combination of two or more.

[0021] The number of functional groups in a polyol is not particularly limited. The hydroxyl value of a polyol is not particularly limited. The weight-average molecular weight of a polyol is not particularly limited. The weight-average molecular weight of a polyol can be measured by gel permeation chromatography (GPC).

[0022] Examples of polyols include polyether polyols, polyester polyols, polyether ester polyols, polycarbonate diols, and polyols with a carbon-carbon bonded main chain. Examples of polyether polyols include polyoxypropylene / polyoxyethylene polyols, polymer polyols, and polyoxytetramethylene glycol. Examples of polyester polyols include aliphatic or aromatic polycondensation polyester polyols and polycaprolactone polyols. Examples of polyols with a carbon-carbon bonded main chain include polybutadiene polyols, polyolefin polyols such as isoprene polyols, and acrylic polyols.

[0023] (1.1) Polyether polyols Examples of polyether polyols include polyether polyols obtained by adding one or more of the following initiators (compounds) to one or more of the following: ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, epichlorohydrin, styrene oxide, etc., or polytetramethylene ether glycol.

[0024] (1.1.1) Initiators (1.1.1.1) Polyhydric alcohols and alkylene oxide adducts of polyhydric alcohols Examples of polyhydric alcohols: [Difunctional alcohols] Ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, trimethylene glycol [Trifunctional alcohols] Glycerin, trimethylolpropane [Quadrophenifunctional alcohols] Pentaerythritol [Hexafunctional alcohols] Sorbitol [Octahedral alcohols] Sucrose (1.1.1.2) Alkylene oxide adducts of polyhydric phenols Examples of alkylene oxide adducts of polyhydric phenols: Alkylene oxide adduct of bisphenol A (1.1.1.3) Polyhydric hydroxy compounds Examples of polyhydric hydroxy compounds: Phosphate, benzenephosphate, polyphosphate (e.g., tripolyphosphate and tetrapolyphosphate), etc. (1.1.1.4) Phenol-aniline-formaldehyde ternary condensation products (1.1.1.5) Aniline-formaldehyde condensation products (1.1.1.6) Polyamines Examples of polyamines: ethylenediamine, diethylenetriamine, triethylenetetramine, methylenebisorthochloroaniline, 4,4- and 2,4'-diphenylmethanediamine, 2,4-tolylenediamine, 2,6-tolylenediamine, etc. (1.1.1.7) Alkanolamines Examples of alkanolamines: triethanolamine, diethanolamine, etc.

[0025] (1.1.2) Polymer Polyols Polymer polyols are polyols obtained by graft polymerization of ethylenically unsaturated compounds such as acrylonitrile, styrene, and alkyl methacrylate onto the polyether polyols described above.

[0026] (1.2) Polyester polyols Polyester polyols are obtained by condensation of one or more compounds having at least two hydroxyl groups with one or more compounds having at least two carboxyl groups, or are ring-opening polymers of cyclic esters such as caprolactone and methylvalerolactone.

[0027] (1.2.1) Examples of compounds having at least two hydroxyl groups: ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,3- and 1,4-butanediol, tetramethylene glycol, neopentyl glycol, methylpentanediol, butylethylpropanediol, hexamethylene glycol, decamethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol

[0028] (1.2.2) Examples of compounds having at least two carboxyl groups: malonic acid, maleic acid, succinic acid, adipic acid, tartaric acid, pimelic acid, azelaic acid, sebacic acid, oxalic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, hemeltic acid

[0029] (1.3) Polycarbonate diols Examples of polycarbonate polyols include those obtained by transesterification reactions of low molecular weight polyols such as butanediol and hexanediol with low molecular weight carbonates such as propylene carbonate and diethyl carbonate.

[0030] (1.4) Polyolefin-based polyols Examples of polyolefin-based polyols include polybutadiene polyols, polyisoprene polyols, hydrogenated polybutadiene polyols, and hydrogenated polyisoprene polyols.

[0031] (1.5) Plant-derived polyols In addition to the polyols mentioned above, plant-derived polyols may also be included as polyols. Examples of plant-derived polyols include castor oil polyols, soybean oil polyols, palm oil polyols, palm kernel oil polyols, coconut oil polyols, cashew oil polyols, olive oil polyols, cottonseed oil polyols, safflower oil polyols, sesame oil polyols, sunflower oil polyols, linseed oil polyols, etc. Plant-derived polyols typically have 2 to 3 hydroxyl functional groups per molecule. Examples of castor oil polyols include castor oil, reaction products of castor oil and polyols, and esterification reaction products of castor oil fatty acids and polyols. Examples of polyols to be reacted with castor oil or castor oil fatty acids include divalent polyols such as ethylene glycol, diethylene glycol, and propylene glycol, or trivalent or higher polyols such as glycerin, trimethylolpropane, hexanetriol, and sorbitol. Examples of soybean oil-based polyols include polyols derived from soybean oil, such as reaction products of soybean oil and polyols, and esterification reaction products of soybean oil fatty acids and polyols. The same polyols as in the case of castor oil can be used to react with soybean oil or soybean oil fatty acids. The same applies to palm oil-based polyols, cashew oil-based polyols, etc., as in the case of soybean oil-based polyols. The various polyols exemplified as plant-derived polyols may be used individually or in combination of two or more.

[0032] (2) Polyisocyanates The polyisocyanates are not particularly limited. Various polyisocyanates may be used alone or in combination of two or more. The polyisocyanates are not particularly limited and may be aromatic, alicyclic, or aliphatic. The polyisocyanates may be difunctional isocyanates having two isocyanate groups in one molecule. The polyisocyanates may be trifunctional or more isocyanates having three or more isocyanate groups in one molecule.

[0033] Examples of bifunctional polyisocyanates include 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), m-phenylenediisocyanate, p-phenylenediisocyanate, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethanediisocyanate (2,4'-MDI), 2,2'-diphenylmethane diisocyanate (2,2'-MDI), xylylene diisocyanate, and 3,3'-dimethyl-4,4'-biphenylenedi. Examples of aromatic diisocyanates include isonates, 3,3'-dimethoxy-4,4'-biphenylenediisocyanate, alicyclic diisocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexane diisocyanate, and aromatic diisocyanates such as butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropyl diisocyanate, methylene diisocyanate, and lysine diisocyanate. Diphenylmethane diisocyanate (MDI) may be used in combination with polymeric MDI and multiple types of polymeric MDI prepolymers.

[0034] Examples of polyisocyanates with three or more functions include 1-methylbenzol-2,4,6-triisocyanate, 1,3,5-trimethylbenzol-2,4,6-triisocyanate, biphenyl-2,4,4'-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate, and triphenylmethane-4,4',4"-triisocyanate.

[0035] The isocyanate index (INDEX) is preferably 80 to 120, more preferably 90 to 118, and even more preferably 100 to 115, from the viewpoint of reaction stability and suppression of heat generation during foaming. The isocyanate index is calculated by dividing the number of moles of isocyanate groups in the polyisocyanate by the total number of moles of hydroxyl groups in the poly-O component and active hydrogen groups such as water as a foaming agent, and multiplying the result by 100. It is calculated as [NCO equivalent of polyisocyanate / active hydrogen equivalent × 100].

[0036] (3) Foaming agent The foaming agent is not particularly limited. Various foaming agents may be used alone or in combination of two or more. Examples of foaming agents include water, hydrocarbons, halogenated compounds, etc. Examples of hydrocarbons include cyclopentane, isopentane, n-pentane, etc. Examples of halogenated compounds include methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, pentafluoroethyl methyl ether, heptafluoroisopropyl methyl ether, etc. Among these, water is particularly preferred as a foaming agent. The water may be deionized water, tap water, distilled water, etc.

[0037] (4) Other Components The first polyurethane foam composition and the second polyurethane foam composition may contain catalysts and auxiliary agents as appropriate. The catalyst may be one known for use in polyurethane foams and is not particularly limited. Examples of usable catalysts include amine catalysts such as triethylamine, triethylenediamine, and tetramethylguanidine; tin catalysts such as dibutyltin dilaurate and stanus octoate; and metal catalysts (also called organometallic catalysts) such as phenylmercury propionate or lead octenoate. The total amount of catalyst to be added may be appropriately determined depending on the type of catalyst.

[0038] Examples of auxiliary agents include foam stabilizers, crosslinking agents, colorants, flame retardants, antibacterial agents, stabilizers, and plasticizers.

[0039] Foam stabilizers known for use with polyurethane foam can be used. Examples of foam stabilizers include silicone-based foam stabilizers, fluorine-containing compound-based foam stabilizers, and surfactants. Silicone-based foam stabilizers are particularly suitable. Examples of silicone-based foam stabilizers include foam stabilizers mainly composed of siloxane chains, foam stabilizers having a linear structure of siloxane chains and polyether chains, branched foam stabilizers, and foam stabilizers in which polyether chains are modified into pendant-like structures of siloxane chains. These foam stabilizers can be used individually or in combination of two or more types.

[0040] Examples of crosslinking agents include polyhydric alcohols such as ethylene glycol, diethylene glycol, glycerin, butanetetraol, and polyoxypropylene glycol, as well as diethanolamine and polyamines. These crosslinking agents can be used individually or in combination of two or more types.

[0041] Polyurethane foam can be either slab foam or mold foam, and the first polyurethane foam layer 3 may be either. The second polyurethane foam layer 5 may also be either slab foam or mold foam. Slab foam is produced by mixing and stirring the polyurethane foam composition, extruding it onto a conveyor, foaming it on the conveyor to continuously form polyurethane foam, and then cutting it to a predetermined size. On the other hand, mold foam is produced by injecting the polyurethane foam composition into a mold and foaming it, and has an external shape corresponding to the internal shape of the mold.

[0042] From the viewpoint of attaching and detaching hook-and-loop fasteners, it is preferable that the first polyurethane foam layer 3 is subjected to a process that forms through holes in the cell membranes of the cells. An example of this process is a defilm removal process that removes the cell membranes. From the viewpoint of ensuring good breathability of the laminate 1, it is preferable that the second polyurethane foam layer 5 is subjected to a process that forms through holes in the cell membranes of the cells. An example of this process is a defilm removal process that removes the cell membranes. For example, known processes for removing the cell membranes of polyurethane foam can be used to form through holes in the cell membranes. For example, a method of dissolving the cell membranes by immersing the polyurethane foam in an alkaline solution, or a method of destroying the cell membranes by causing an explosion by placing the polyurethane foam in a sealed container, filling the sealed container with a flammable gas such as oxygen, and then igniting it.

[0043] 6. The method for bonding the first polyurethane foam layer 3 and the second polyurethane foam layer 5 is not particularly limited, as long as the physical properties of the laminate 1 can be ensured. For bonding, for example, a compound having an NCO terminator can be used as a binder. As a compound having an NCO terminator, a prepolymer having an NCO terminator is preferably used from the viewpoint of ensuring breathability after bonding. The prepolymer is preferably melted into a fluid at a temperature of 60°C to 80°C. The prepolymer is preferably one that rapidly develops thermosetting properties when heated to a predetermined temperature, from the viewpoint of suppressing seepage into the first polyurethane foam layer 3 and the second polyurethane foam layer 5 during bonding. The prepolymer is preferably one whose viscosity when melted is 0.1 Pa·s or more and Pa·s or less, from the viewpoint of suppressing seepage into the first polyurethane foam layer 3 and the second polyurethane foam layer 5 during bonding.

[0044] Suitable polyol components used as raw materials for prepolymers are compounds having two or more hydroxyl groups, generally referred to as polyols, such as polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, ethylene glycol, or glycerin, either alone or in mixtures. In addition, compounds having active hydrogen such as carboxylic acids or amines instead of hydroxyl groups can also be used. Suitable isocyanate components include tolylene diisocyanate, diphenylmethane diisocyanate, or naphthalene diisocyanate. Diphenylmethane diisocyanate (MDI) is particularly preferred from the standpoint of manufacturing cost.

[0045] The melting temperature of a prepolymer is basically determined by its molecular weight; the smaller the molecular weight, the lower the melting temperature. When the melting temperature is set to be between 60°C and 80°C, a molecular weight of approximately 400-10,000 is preferable for the prepolymer. The molecular weight of the prepolymer is determined by the molecular weights of the polyol and isocyanate components, and the stirring time, i.e., the reaction (polymerization) time. For example, to obtain a prepolymer with a molecular weight of approximately 500, a polyol with a molecular weight of approximately 200 and an isocyanate with a molecular weight of approximately 330 should be mixed and stirred for approximately 24 hours. Note that all molecular weights here refer to number-average molecular weights.

[0046] The prepolymer obtained in this way undergoes instantaneous polymerization and resinification reactions when heated to 110-130°C in the presence of moisture and a catalyst, becoming a thermosetting resin. Therefore, the prepolymer is a substance that behaves as follows: it is a solid state with good handling properties at room temperature, a reversible fluid state with a predetermined viscosity when heated to 60-80°C, and exhibits thermosetting properties when further heated to around 110-130°C, becoming a passive material at higher temperatures thereafter.

[0047] Furthermore, compared to binders containing only isocyanates, which are commonly used, the prepolymer has already undergone some degree of polymerization and resinification reactions, which has the advantage of allowing the reaction to proceed to thermosetting resin in a shorter time. Consequently, the hot pressing time required to form the laminate 1 from the first polyurethane foam layer 3 and the second polyurethane foam layer 5 in the lamination integration process described later can be shortened, meaning that the total amount of heat supplied can also be reduced. This effect significantly suppresses the seepage of the binder into the first polyurethane foam layer 3 and the second polyurethane foam layer 5 due to the instantaneous melting of the binder during this hot pressing. By suppressing the seepage of the binder, the formation of a non-permeable adhesive layer between the first polyurethane foam layer 3 and the second polyurethane foam layer 5 can be prevented.

[0048] The mixing ratio of the polyol component and the isocyanate component is set so that the isocyanate index at the time of mixing is 250 or higher, so that the resulting prepolymer contains unreacted NCO groups that exhibit adhesive properties as a binder. The unreacted NCO groups form urea bonds when heated in the presence of moisture and a catalyst during the process of laminating and integrating the first polyurethane foam layer 3 and the second polyurethane foam layer 5. The urea bonds result in strong adhesion between the first polyurethane foam layer 3 and the second polyurethane foam layer 5.

[0049] The prepolymer is applied by heating the prepolymer to a melted state and applying the required amount to one of the bonding surfaces (surfaces) of the first polyurethane foam layer 3 and the second polyurethane foam layer 5.

[0050] The prepolymer melts and becomes fluid when heated to 60°C or higher. This allows the prepolymer to be applied in a predetermined amount using a coating device. The application method is not particularly limited and may be, for example, dot application or linear application. Examples of coating devices include various coating devices such as spray devices and roll coaters. By employing dot application, linear application, or spray application, the breathability of the laminate 1 is improved. The amount applied is not particularly limited. From the viewpoint of sufficiently bonding the first polyurethane foam layer 3 and the second polyurethane foam layer 5, the amount applied is 10 g / m². ２ The above is preferable, and 25 g / m ２ The above is more preferable: 30 g / m ２ The above is even more preferable. The above coating amount is 150 g / m², from the viewpoint of ensuring sufficient breathability of the laminate 1. ２ The following is preferable: 100 g / m ２ The following is more preferable: 80 g / m ２ The following is even more preferable. From these viewpoints, the above coating amount is 10 g / m². ２ 150g / m or more ２ The following is preferable: 25 g / m ２ More than 100g / m ２ The following is more preferable: 30 g / m ２ 80g / m or more ２ The following is even more preferable.

[0051] Moisture and a catalyst are applied to the other adhesive surface (surface) of the first polyurethane foam layer 3 and the second polyurethane foam layer 5. A pre-laminate is formed by stacking the first polyurethane foam layer 3 and the second polyurethane foam layer 5 with their adhesive surfaces facing each other. The pre-laminate is hot-pressed as needed. When the pre-laminate is heated in the presence of moisture and a catalyst, a portion of the prepolymer polymerizes and resinifies to become polyurethane resin, exhibiting an adhesive effect through a physical anchoring effect. At the same time, unreacted NCO groups resinify and exhibit a chemical adhesive effect, thus fulfilling their role as an adhesive material. The method of further heating after applying a binder (adhesive) to accelerate the curing speed is called the elastoquilt method.

[0052] 7. Applications of Laminate 1 The applications of the laminate 1 of this disclosure are not particularly limited. In the laminate 1, the surface 3A of the first polyurethane foam layer 3 can serve as an attachment point for hook-and-loop fasteners 11. The hook-and-loop fasteners 11 are detachably attached to the surface 3A by hooking onto the polyurethane foam skeleton exposed on the surface 3A. The laminate 1 can be used in head accessories 9. Examples of head accessories 9 include helmets, headgear, and hats. Figures 2 and 3 disclose a helmet as an example of a head accessory 9. The head accessory 9 is used, for example, for head protection and for correcting the shape of the skull. The hooks of the hook-and-loop fasteners 11 hook onto the polyurethane foam skeleton on the surface 3A of the first polyurethane foam layer 3, thereby detachably attaching the laminate 1 to the head accessory 9.

[0053] 8. Effects of Laminate 1 The laminate 1 of this disclosure has good cushioning, breathability, and ease of attachment and detachment of the hook-and-loop fastener 11. The number of cells in the first polyurethane foam layer 3, based on JIS K6400-1:2004 Annex A, is 6 cells / 25 mm or more and 40 cells / 25 mm or less, so that the hook-and-loop fastener 11 can be easily attached and detached to the first polyurethane foam layer 3. The rebound elasticity of the second polyurethane foam layer 5, based on JIS K 6400-3:2011, is 15% or less, so that the cushioning function of the laminate 1 can be ensured. The laminate 1 of this disclosure has excellent cushioning properties because the second polyurethane foam layer 5 ensures low rebound and rebound elasticity. The laminate 1 of this disclosure can ensure breathability by removing the film from the first polyurethane foam layer 3. The laminate 1 of this disclosure can ensure breathability while maintaining cushioning properties by removing the film from the second polyurethane foam layer 5. It is preferable to use a compound having NCO terminators for bonding the first polyurethane foam layer 3 and the second polyurethane foam layer 5. By using this compound, bonding can be performed without blocking any cells in either the first polyurethane foam layer 3 or the second polyurethane foam layer 5, thus ensuring breathability of the laminate 1. For example, if the first polyurethane foam layer 3 and the second polyurethane foam layer 5 are bonded using double-sided tape, the breathability of the laminate 1 may be impaired by the resin film that is a component of the double-sided tape. However, by using a compound having NCO terminators for bonding, the resin film is not used, thus suppressing a decrease in the breathability of the laminate 1. Because breathability is ensured by using a compound having NCO terminators for bonding, the laminate 1 dries well after washing. Because breathability is ensured by using a compound having NCO terminators for bonding, it is less prone to stuffiness and more comfortable when used as a cushioning material in applications that come into contact with the human body. By using a compound having NCO terminators for bonding, a decrease in the flexibility of the laminate 1 due to bonding can be suppressed. For example, if the first polyurethane foam layer 3 and the second polyurethane foam layer 5 are bonded together using double-sided tape or the like, the flexibility of the laminate 1 may be impaired by the resin film that is a component of the double-sided tape.However, by using a compound with NCO terminology for bonding, a resin film is not used, thus suppressing a decrease in the flexibility of the laminate 1. By using a compound with NCO terminology for bonding, the adhesion between the first polyurethane foam layer 3 and the second polyurethane foam layer 5 becomes stronger, making them less likely to peel apart. By using a compound with NCO terminology for bonding, it is possible to achieve both flexibility and adhesive strength while ensuring breathability. The laminate 1, which has an attachment portion for the hook-and-loop fastener 11, can be easily attached to an article because it can be detachably attached.

[0054] 9. Effects of the head-mounted device 9 The head-mounted device 9, equipped with a laminate 1, has excellent cushioning and breathability. If hook-and-loop fasteners 11 are used to secure the laminate 1, the securing of the laminate 1 becomes easy, and the replacement of the laminate 1 becomes easy.

[0055] 1. First Polyurethane Foam Layer 3 and Second Polyurethane Foam Layer 5 (1) The prepared polyurethane foam composition was stirred and mixed, and foamed to produce foams 1-1 to 1-5 (first polyurethane foam layer 3) and foams 2-1 to 2-3 (second polyurethane foam layer 5). All polyurethane foams are slab foam products. Foams 1-1, 1-2, 1-4, 1-5, 2-1, and 2-3 were subjected to defilm removal treatment by explosion to remove the cell membrane. On the other hand, foams 1-3 and 2-2 were not subjected to defilm removal treatment. Foam 1-2 is a defilm removed product of foam 1-3. Foam 2-1 is a defilm removed product of foam 2-2.

[0056] (2) Physical properties of the first polyurethane foam layer 3 and the second polyurethane foam layer 5 The physical properties of the first polyurethane foam layer 3 and the second polyurethane foam layer 5 were measured using the following measurement methods: Air permeability: JIS K6400-7 Method A: 2012 Apparent density: JIS K7222: 2005 Number of cells: JIS K6400-1: 2004 Annex A Rebound elasticity: JIS K 6400-3: 2011

[0057]

[0058] 2. Laminate 1 (1) The first polyurethane foam layer 3 and the second polyurethane foam layer 5 in the manufactured laminate 1 were manufactured in the combinations shown in Table 1. For example, in Example 1, the combination was foam 1-1 and foam 2-1. Laminate 1 was manufactured by bonding a first polyurethane foam layer 3 with a thickness of 3.0 mm and a second polyurethane foam layer 5 with a thickness of 9.5 mm.

[0059] (1.1) Preparation of Examples 1, 2, 3 and Comparative Examples 1, 2, 3, and 4 Examples 1, 2, 3 and Comparative Examples 1, 2, 3, and 4 were bonded using a compound having an NCO terminus. Specifically, the following compound (prepolymer) was used as the compound having an NCO terminus. <Compound having an NCO terminus> Foamlite 0135B (manufactured by BASF INOAC Polyurethanes)

[0060] To prepare laminate 1, a prepolymer was first applied to the bonding surface of the second polyurethane foam layer 5. The compound with NCO terminology was applied by heating the compound to a molten state and then applying the required amount to the bonding surface (surface) of the second polyurethane foam layer 5. The amount of prepolymer applied was 50 g / m². ２ Next, moisture and a catalyst were applied to the adhesive surface (surface) of the first polyurethane foam layer 3. A preliminary laminate was created by stacking the adhesive surfaces of the first polyurethane foam layer 3 and the second polyurethane foam layer 5 together. The preliminary laminate was subjected to hot pressing (140°C). Laminate 1 was thus manufactured.

[0061] (1.2) The material for Comparative Example 5 was bonded using adhesive tape (manufactured by Nitto Denko, model number No. 501L).

[0062] (2) Characteristics of Laminate 1 (2.1) Evaluation Method for Characteristics of Laminate 1 The characteristics of laminate 1 were evaluated as follows: <Air permeability> A test specimen of laminate 1, which is made by bonding a first polyurethane foam layer 3 with a thickness of 3.0 mm and a second polyurethane foam layer 5 with a thickness of 9.5 mm, was measured in accordance with JIS K6400-7 Method A:2012. The air permeability was evaluated as follows: Evaluation A: Air permeability 25 cm ３ / cm ２- S or higher. Rating B: Air permeability 25 cm ３ / cm ２ It is less than s.

[0063] <Cushioning> The cushioning was evaluated as follows: Evaluation A: The rebound elasticity of the second polyurethane foam layer 5 is 15% or less. Evaluation B: The rebound elasticity of the second polyurethane foam layer 5 is greater than 15%.

[0064] <Adhesion of hook-and-loop fastener> An attempt was made to attach the hook (side A, male) of the hook-and-loop fastener 11 to the surface of the first polyurethane foam layer 3 of the laminate 1. The adhesion of the hook-and-loop fastener was evaluated as follows: Evaluation A: The adhesion of the hook-and-loop fastener 11 is good. Evaluation B: The hook-and-loop fastener 11 sticks. However, it peels off a little easily. Evaluation C: The hook-and-loop fastener 11 does not stick well.

[0065] <Washability and Drying Properties> The washability and drying properties of laminate 1 were evaluated as follows, referring to the air permeability of laminate 1. Evaluation A: The air permeability of laminate 1 is evaluated as A. Evaluation B: The air permeability of laminate 1 is evaluated as B.

[0066] (2.2) Evaluation results of the properties of the laminate 1 In Examples 1, 2, and 3, the evaluations for breathability, cushioning, and wash-dryability were all "A". In Examples 1, 2, and 3, the evaluation for hook-and-loop fastener adhesion was "A" or "B". Therefore, Examples 1, 2, and 3 had good cushioning, breathability, and ease of attachment and detachment of the hook-and-loop fastener 11. In Comparative Example 1, the evaluation for hook-and-loop fastener adhesion was "C". Specifically, in Comparative Example 1, the cell membrane of the first polyurethane foam layer 3 interfered, making it difficult for the hook-and-loop fastener 11 to adhere. In Comparative Example 1, the evaluation for breathability was "B". Specifically, in Comparative Example 1, the cell membrane of the first polyurethane foam layer 3 interfered, resulting in low breathability. In Comparative Example 1, due to the low breathability, the evaluation for wash-dryability was also low at "B". In Comparative Example 2, the evaluation for hook-and-loop fastener 11 adhesion was "C". Specifically, in Comparative Example 2, the hooks of the hook-and-loop fastener 11 had difficulty getting between the fine cells of the first polyurethane foam layer 3, resulting in a low evaluation of adhesion. In Comparative Example 3, the evaluation of breathability was "B". Specifically, in Comparative Example 3, the cell membrane of the second polyurethane foam layer 5 interfered, resulting in low breathability. In Comparative Example 3, due to the low breathability, the evaluation of washability and drying performance was also low, at "B". In Comparative Example 4, the rebound elasticity of the second polyurethane foam layer 5 was greater than 15%, resulting in a low evaluation of cushioning performance, at "B". In Comparative Example 5, the evaluation of breathability was "B". Specifically, in Comparative Example 5, the adhesive tape (resin film of the adhesive tape) interfered, resulting in low breathability. In Comparative Example 5, due to the low breathability, the evaluation of washability and drying performance was also low, at "B".

[0067] 3. Drying speed test regarding wash-drying properties (1) Test method (1.1) The test specimens for Example 1 were prepared as follows. For the laminate 1 of Example 1, a blade was made perpendicular to the surface of the first polyurethane foam layer 3 to cut out a rectangular parallelepiped measuring 50 mm × 50 mm × 10 mm (length × width × thickness) to serve as the test specimen. For each of foams 2-1 and 2-2, a rectangular parallelepiped measuring 50 mm × 50 mm × 10 mm (length × width × thickness) was cut out to serve as the test specimen. Each test specimen for foams 2-1 and 2-2 is a single layer. (1.2) The weight of each test specimen was measured. (1.3) 3.5 mL of tap water was impregnated into each test specimen using a syringe. (1.4) The weight of each test specimen after impregnation (weight of the test specimen immediately after water absorption) was measured. (1.5) Each test specimen was left to dry in a test chamber at 23°C. (1.6) For each test specimen, the weight (weight of the test specimen after drying for a predetermined time) was measured between 10 minutes and 24 hours after the test. The drying rate (%) was calculated using the following formula: Drying rate (%) = (Amount of water evaporated (g) / Amount of water absorbed (g)) × 100 Amount of water evaporated (g) = Weight of the test specimen immediately after water absorption (g) - Weight of the test specimen after drying for a predetermined time (g) Amount of water absorbed (g) = Weight of the test specimen immediately after water absorption (g) - Weight of the test specimen before water absorption (g)

[0068] (2) Test Results The test results are shown in Table 2 and Figure 4. It was confirmed that Example 1 had a faster drying speed compared to Forms 2-1 and 2-2.

[0069]

[0070] This disclosure is not limited to the embodiments detailed above, and various modifications or alterations are possible.

[0071] 1...Laminate 3...First polyurethane foam layer 3A...Surface 5...Second polyurethane foam layer 9...Head attachment 11...Velcro fastener

Claims

1. A laminate in which a first polyurethane foam layer and a second polyurethane foam layer are bonded together, wherein the number of cells in the first polyurethane foam layer according to JIS K6400-1:2004 Annex A is 6 cells / 25 mm or more and 40 cells / 25 mm or less, and the rebound elasticity of the second polyurethane foam layer according to JIS K 6400-3:2011 is 15% or less, and when a test specimen of this laminate, which is bonded together with the first polyurethane foam layer having a thickness of 3.0 ± 1.0 mm and the second polyurethane foam layer having a thickness of 9.5 ± 1.0 mm, is measured according to JIS K6400-7 Method A:2012, the air permeability is 25 cm ３ / cm ２ - A laminate that is s or greater.

2. The laminate according to claim 1, wherein the first polyurethane foam layer is defilmed.

3. The laminate according to claim 1 or claim 2, wherein the adhesion between the first polyurethane foam layer and the second polyurethane foam layer is performed using a compound having an NCO terminus.

4. The laminate according to claim 1 or claim 2, wherein the surface of the first polyurethane foam layer is an attachment portion for a hook-and-loop fastener, and the hook-and-loop fastener is detachably attached to the surface by hooking onto the polyurethane foam skeleton exposed on the surface.

5. A head-mounted device comprising the laminate described in claim 1 or claim 2.

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