Cushioning materials, exterior materials and robot parts

Abstract

A buffer material 1 is provided with a gel layer 3 and a skin layer 4. The gel layer 3 contains polyurethane gel. The gel layer 3 has a storage modulus (E'gel) of 0.01 MPa or more and 10 MPa or less at 23°C. The skin layer 4 is disposed on one surface of the gel layer 3. The 100% modulus of the skin layer 4 is 5.0 MPa or less, and / or the skin layer 4 has a fine concavo-convex structure on a surface thereof. The arithmetic average roughness Ra of the surface of the skin layer 4 measured according to the following conditions is more than 0 μm and 10 μm or less.　Measurement conditions of arithmetic average roughness Ra: a spherical contact having a diameter φ of 1.6 mm, a specification load of 0.4 gf, a measurement length of 40 mm, a cutoff wavelength of 0.8 mm, a measurement speed of 0.15 mm / sec

Description

[Technical Field]

[0001] The present invention relates to a cushioning material, an exterior material, and a robot part. [Background technology]

[0002] Gels have been known as buffer materials. It is also known to dispose a coating layer on the surface of a gel. More specifically, for example, the following polyurethane gels are known. That is, the polyurethane gel comprises a gel layer and a coating layer that covers the gel layer. The gel layer is obtained by at least reacting an aliphatic polyisocyanate having an average functionality of more than 2.0 with a polyol having an average functionality of 3.0 or less. The coating layer is obtained by at least reacting an aliphatic diisocyanate and / or an alicyclic diisocyanate with a bifunctional active hydrogen compound (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 010422 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, as a cushioning material, depending on the application, an improved feel to the touch is required. More specifically, smoothness against sliding is required. Furthermore, there are cases where a high level of smoothness against sliding is required.

[0005] The present invention relates to a cushioning material, an exterior material, and a robot part that have an excellent feel to the touch. [Means for solving the problem]

[0006] The present invention [1] is a buffer material comprising a gel layer and a surface layer, wherein the gel layer contains polyurethane gel, and the storage modulus (E') of the gel layer at 23°C is gel ) is 0.01 MPa or more and 10 MPa or less, the skin layer is disposed on one side of the gel layer, the 100% modulus of the skin layer is 5.0 MPa or less, and / or the skin layer includes a buffer material having a fine uneven structure on the surface, and the arithmetic mean roughness Ra of the surface of the skin layer measured under the following conditions is more than 0 μm and 10 μm or less.

[0007] Arithmetic mean roughness Ra measurement conditions: spherical φ1.6 mm contact, specified load 0.4 gf, measurement length 40 mm, cutoff wavelength 0.8 mm, measurement speed 0.15 mm / sec

[0008] The present invention [2] includes the cushioning material according to the above [1], wherein the average thickness of the surface layer is 10 μm or more and 1000 μm or less.

[0009] The present invention [3] includes the cushioning material according to the above [1] or [2], further comprising a foam layer, the foam layer being disposed on the other side of the gel layer opposite the one side, the foam layer having an average thickness of 1000 μm or more and 50000 μm or less, and the gel layer having an average thickness of 500 μm or more and 10000 μm or less.

[0010] The present invention [4] is characterized in that the density of the foamed layer is 80 kg / m 3 More than 200kg / m 3 and the density of the gel layer is 500 kg / m or less. 3 More than 1200kg / m 3 The cushioning material includes the cushioning material described in [3] above.

[0011] The present invention [5] includes a cushioning material comprising the cushioning material according to any one of the above [1] to [4].

[0012] The present invention [6] includes a robot part including the cushioning material according to any one of the above [1] to [4]. [Effects of the Invention]

[0013] The cushioning material, exterior packaging material, and robot component of the present invention comprise a gel layer having a predetermined storage modulus and a skin layer disposed on one side of the gel layer. The 100% modulus of the skin layer is below a predetermined value, and / or the skin layer has a micro-convexo-concave structure on its surface, and the arithmetic mean roughness Ra of the surface of the skin layer is below a predetermined value. Therefore, the cushioning material, exterior packaging material, and robot component of the present invention have an excellent tactile feel. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram of an embodiment of the cushioning material of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] In Fig. 1, the cushioning material 1 includes a polyurethane gel with a skin 2. The polyurethane gel with a skin 2 includes a gel layer 3 and a skin layer 4 disposed on one side of the gel layer 3. In Fig. 1, the one side is the upper side of the paper, and the other side relative to the one side is the lower side of the paper.

[0016] The gel layer 3 includes a polyurethane gel. The gel layer 3 is preferably made of a polyurethane gel. The polyurethane gel has excellent elasticity. Therefore, when the gel layer 3 is made of a polyurethane gel, the cushioning material 1 has excellent elasticity and excellent cushioning performance.

[0017] The polyurethane gel is a polyurethane elastomer with ultra-low hardness. The polyurethane gel is defined by its storage modulus. The storage modulus (E') of the polyurethane gel at 23°C is 0.01 MPa or more and 10 MPa or less. The storage modulus (E') of the polyurethane gel is preferably within the range of the storage modulus of the gel layer 3 described below.

[0018] The storage modulus is a value measured at 23° C. when the temperature dependency (10 Hz) of dynamic viscoelasticity is measured. The storage modulus is measured in accordance with the examples described later (the same applies hereinafter).

[0019] The polyurethane gel includes a reaction product of a gel isocyanate component and a gel active hydrogen group-containing component. More specifically, the polyurethane gel is obtained by reacting the gel isocyanate component with the gel active hydrogen group-containing component.

[0020] The isocyanate component for the gel includes, for example, a polyisocyanate monomer and a polyisocyanate derivative.

[0021] Examples of the polyisocyanate monomer include aromatic polyisocyanate monomers, araliphatic polyisocyanate monomers, and aliphatic polyisocyanate monomers.

[0022] Examples of aromatic polyisocyanate monomers include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), toluidine diisocyanate (TODI), paraphenylene diisocyanate, and naphthalene diisocyanate (NDI). Examples of diphenylmethane diisocyanates include 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 4,4'-diphenylmethane diisocyanate. These can be used alone or in combination of two or more types.

[0023] Examples of aromatic aliphatic polyisocyanate monomers include xylylene diisocyanate (XDI) and tetramethyl xylylene diisocyanate (TMXDI). Examples of xylylene diisocyanate include 1,3-xylylene diisocyanate and 1,4-xylylene diisocyanate. These can be used alone or in combination of two or more types.

[0024] Examples of aliphatic polyisocyanate monomers include trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), 1,2-propane diisocyanate, 1,2-butane diisocyanate, 2,3-butane diisocyanate, 1,3-butane diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methyl caproate. These can be used alone or in combination of two or more.

[0025] The aliphatic polyisocyanate monomer also includes an alicyclic polyisocyanate monomer. Examples of the alicyclic polyisocyanate monomer include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), and methylenebis(cyclohexyl isocyanate) (H 12 MDI) and bis(isocyanatomethyl)cyclohexane (H6XDI). These can be used alone or in combination of two or more.

[0026] Examples of polyisocyanate derivatives include modified products of the above-mentioned polyisocyanate monomers. Examples of modified products include uretdione modified products, isocyanurate modified products, allophanate modified products, polyol modified products, biuret modified products, urea modified products, oxadiazinetrione modified products, and carbodiimide modified products. Further examples of polyisocyanate derivatives include polymethylene polyphenylene polyisocyanate (crude MDI, polymeric MDI). These can be used alone or in combination of two or more types.

[0027] From the viewpoints of mechanical properties and tactile feel, the isocyanate component for the gel is preferably a polyisocyanate derivative, more preferably a derivative of an aliphatic polyisocyanate monomer, still more preferably an isocyanurate derivative of an aliphatic polyisocyanate monomer, and particularly preferably an isocyanurate derivative of pentamethylene diisocyanate. Furthermore, a biomass-derived raw material may be blended as the isocyanate component for the gel.

[0028] The average number of isocyanate groups in the isocyanate component for gel is, for example, 1.8 or more, preferably 2.0 or more. The average number of isocyanate groups in the isocyanate component for gel is, for example, 4.0 or less, preferably 3.5 or less. When the average number of isocyanate groups in the isocyanate component for gel is within the above range, a gel-like polyurethane resin can be efficiently obtained. In other words, the polyurethane gel can be produced with excellent production efficiency. The average number of isocyanate groups in the isocyanate component for gel is calculated based on the formulation using a known method.

[0029] The active hydrogen group-containing gel component is a component having two or more active hydrogen groups (hydroxyl groups, amino groups, etc.) in one molecule. Examples of the active hydrogen group-containing gel component include polyol components for gels. Examples of the polyol components for gels include macropolyols and low molecular weight polyols.

[0030] Macropolyols are organic compounds with relatively high molecular weights, each molecule having two or more hydroxyl groups. The number-average molecular weight of macropolyols is, for example, 400 or more and, for example, 20,000 or less. The number-average molecular weight can be calculated by a known method from the hydroxyl group equivalent weight and the average number of hydroxyl groups. The number-average molecular weight can also be measured as a polystyrene-equivalent molecular weight by gel permeation chromatography (the same applies below).

[0031] Examples of macropolyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These macropolyols can be used alone or in combination of two or more. Preferred examples of macropolyols include polyether polyols.

[0032] Examples of polyether polyols include polyoxyalkylene polyols, such as polyoxyalkylene (C2-3) polyols and polytetramethylene ether polyols.

[0033] Examples of polyoxyalkylene (C2-3) polyols include polyoxyethylene polyols, polyoxypropylene polyols, polyoxytriethylene polyols, and polyoxyethylene-polyoxypropylene polyols (random or block copolymers).

[0034] Examples of polytetramethylene ether polyols include ring-opening polymers (crystalline polytetramethylene ether glycols) obtained by cationic polymerization of tetrahydrofuran. Examples of polytetramethylene ether polyols also include amorphous polytetramethylene ether glycols. Amorphous polytetramethylene ether glycols are copolymerized with tetrahydrofuran and alkyl-substituted tetrahydrofuran and / or dihydric alcohols. Crystalline refers to a property of being solid at 25°C. Amorphous refers to a property of being liquid at 25°C.

[0035] The macropolyol can be used alone or in combination of two or more kinds. As the macropolyol, preferably, polyether polyol is used, more preferably, polytetramethylene ether polyol is used, more preferably, polytetramethylene ether glycol is used, and even more preferably, amorphous polytetramethylene ether glycol is used.

[0036] In the active hydrogen group-containing component for gel, the number average molecular weight of the macropolyol is, for example, 400 or more, preferably 500 or more, and more preferably 1000 or more. The number average molecular weight of the macropolyol is, for example, 15000 or less, preferably 13000 or less, more preferably 12000 or less, even more preferably 10000 or less, still more preferably 5000 or less, and particularly preferably 3000 or less.

[0037] The low-molecular-weight polyol is an organic compound having two or more hydroxyl groups in one molecule and a relatively low molecular weight. The molecular weight of the low-molecular-weight polyol is, for example, 40 or more and less than 400, preferably 300 or less.

[0038] Examples of low-molecular-weight polyols include dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols. Examples of dihydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of trihydric alcohols include glycerin and trimethylolpropane. Examples of tetrahydric or higher alcohols include pentaerythritol and diglycerin. Examples of low-molecular-weight polyols include polymers obtained by addition polymerization of alkylene (C2-C3) oxide with dihydric to tetrahydric alcohols to give a number-average molecular weight of less than 400. These may be used alone or in combination.

[0039] As the low molecular weight polyol, preferably, dihydric alcohols and trihydric alcohols are used, and more preferably, dihydric alcohols are used.

[0040] The active hydrogen group-containing gel component preferably does not contain a low-molecular-weight polyol and contains only a macropolyol. That is, the active hydrogen group-containing gel component is composed of a macropolyol. Furthermore, a biomass-derived raw material may be blended as the active hydrogen group-containing gel component.

[0041] The average number of hydroxyl groups in the active hydrogen group-containing gel component (total amount) is, for example, 2.0 or more. The average number of hydroxyl groups in the active hydrogen group-containing gel component (total amount) is, for example, 3.0 or less, preferably 2.5 or less. The average number of hydroxyl groups in the active hydrogen group-containing gel component is particularly preferably 2.0.

[0042] The average hydroxyl value (OH value) of the active hydrogen group-containing gel component (total amount) is, for example, 10 mg KOH / g or more, preferably 20 mg KOH / g or more, more preferably 30 mg KOH / g or more, and more preferably 50 mg KOH / g or more. The average hydroxyl value (OH value) of the active hydrogen group-containing gel component (total amount) is, for example, 150 mg KOH / g or less, preferably 120 mg KOH / g or less, and more preferably 100 mg KOH / g or less. The hydroxyl value is measured in accordance with the description of JIS K 1557-1 (2007).

[0043] To obtain the gel layer 3, the gel isocyanate component and the gel active hydrogen group-containing component are subjected to a urethane reaction in a predetermined mold. The urethane reaction may be a solvent-free reaction or a reaction in the presence of a solvent. A solvent-free reaction is preferred.

[0044] In the urethanization reaction, a known method is used. Examples of the reaction method include the one-shot method and the prepolymer method. The one-shot method is preferred. In the urethane reaction, the equivalent ratio of the isocyanate groups in the isocyanate component for gel to the active hydrogen groups in the isocyanate component for gel (NCO / active hydrogen groups) is, for example, 0.2 or more, preferably 0.4 or more, and for example, 0.8 or less, preferably 0.7 or less. The reaction temperature is, for example, room temperature to 120°C. The reaction time is, for example, 5 minutes to 72 hours. The reaction temperature may be constant, or may be increased or decreased in stages.

[0045] Then, the isocyanate component for gel and the active hydrogen group-containing component for gel react to obtain the gel layer 3. The gel layer 3 is cured as necessary and then released from the mold.

[0046] Alternatively, to obtain the gel layer 3, the isocyanate component for gel and the active hydrogen group-containing component for gel can be reacted in the presence of a plasticizer.

[0047] The plasticizer is not particularly limited, but examples thereof include phthalic acid plasticizers, hydrogenated phthalic acid plasticizers, and adipic acid plasticizers. Examples of phthalic acid plasticizers include diundecyl phthalate, dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, and dibutyl phthalate. Examples of hydrogenated phthalic acid plasticizers include hydrogenated diisononyl phthalate. Examples of adipic acid plasticizers include dioctyl adipate. These may be used alone or in combination of two or more.

[0048] The proportion of the plasticizer relative to 100 parts by mass of the active hydrogen group-containing gel component is, for example, 10 parts by mass or more, preferably 50 parts by mass or more, more preferably 100 parts by mass or more, and the proportion of the plasticizer relative to 100 parts by mass of the active hydrogen group-containing gel component is, for example, 1000 parts by mass or less, preferably 500 parts by mass or less, more preferably 200 parts by mass or less.

[0049] In the above reaction, known additives can be added as needed. Examples of additives include urethane catalysts, fillers, storage stabilizers, antiblocking agents, heat stabilizers, light stabilizers, UV absorbers, antioxidants, antifoaming agents, mold release agents, pigments, dyes, lubricants, and hydrolysis inhibitors. The blending ratio of the additives is appropriately set.

[0050] The timing of adding the additive is not particularly limited. For example, the additive may be added to the isocyanate component for gel formation. Alternatively, the additive may be added to the active hydrogen group-containing component for gel formation. Alternatively, the additive may be added to both the isocyanate component for gel formation and the active hydrogen group-containing component for gel formation. Furthermore, the additive may be added when the isocyanate component for gel formation and the active hydrogen group-containing component for gel formation are mixed.

[0051] The storage modulus (E') of gel layer 3 at 23°C gel ) is 0.01 MPa or more, preferably 0.03 MPa or more, more preferably 0.05 MPa or more, even more preferably 0.07 MPa or more, and particularly preferably 0.1 MPa or more. In addition, the storage modulus (E') of the gel layer 3 at 23°C is gel The storage modulus (E') of the gel layer 3 at 23°C is 10 MPa or less, preferably 5 MPa or less, more preferably 1 MPa or less, even more preferably 0.5 MPa or less, and particularly preferably 0.3 MPa or less. gel ) is within the above range, a cushioning material with excellent tactile feel can be obtained.

[0052] The average thickness of the gel layer 3 is set depending on the type of mold, etc. From the viewpoint of obtaining a better feel, the average thickness of the gel layer 3 is, for example, 300 μm or more, preferably 500 μm or more, and more preferably 1000 μm or more. From the viewpoint of obtaining a better feel, the average thickness of the gel layer 3 is, for example, 20000 μm or less, preferably 10000 μm or less, and more preferably 5000 μm or less.

[0053] The density of the gel layer 3 is set to, for example, 100 kg / m from the viewpoint of obtaining a better feel. 3 More than 500 kg / m 3 More preferably, 800 kg / m 3 The density of the gel layer 3 is set to, for example, 3000 kg / m from the viewpoint of obtaining a better feel. 3 Preferably, 2000 kg / m or less 3 or less, more preferably 1200 kg / m 3 More preferably, 1000 kg / m or less 3 The following is the result.

[0054] The skin layer 4 is disposed in contact with one surface of the gel layer 3. In other words, the skin layer 4 is laminated on the surface side (upper side of the paper) of the gel layer 3. The skin layer 4 has a predetermined modulus, which will be described later, and / or a predetermined surface roughness, which will be described later.

[0055] An example of the skin layer 4 is a polyurethane resin layer. More specifically, an example of the skin layer 4 is a cured polyurethane resin film. The cured polyurethane resin film is formed, for example, by curing a solution and / or dispersion (coating liquid) containing the polyurethane resin. For example, when the skin layer 4 has a predetermined modulus as described below, the polyurethane resin is designed so that the 100% modulus of the skin layer 4 falls within the range as described below.

[0056] More specifically, examples of coating liquids containing polyurethane resins include one-component curing polyurethane compositions and two-component curing polyurethane compositions. The two-component curing polyurethane composition is preferred as the coating liquid.

[0057] A two-component curing polyurethane composition is, for example, a resin kit including an isocyanate component (curing agent) for the surface layer and an active hydrogen group-containing component (main component) for the surface layer. The main component and curing agent are mixed at the time of use, and the mixture is cured. This forms a polyurethane resin layer.

[0058] Examples of the isocyanate component (curing agent) for the surface include the polyisocyanate monomer, the polyisocyanate derivative, and the isocyanate-terminated prepolymer. These can be used alone or in combination of two or more. A preferred isocyanate component for the surface is the isocyanate-terminated prepolymer.

[0059] The isocyanate-terminated prepolymer is, for example, a reaction product of a first raw material polyisocyanate and a first raw material polyol. Examples of the first raw material polyisocyanate include the polyisocyanate monomers and / or polyisocyanate derivatives described above. These can be used alone or in combination of two or more types.

[0060] The first raw material polyisocyanate is preferably a polyisocyanate derivative, more preferably a derivative of an aliphatic polyisocyanate monomer, even more preferably an isocyanurate-modified product of an aliphatic polyisocyanate monomer, and even more preferably an isocyanurate derivative of hexamethylene diisocyanate.

[0061] Examples of the first raw material polyol include the macropolyols and the low molecular weight polyols described above. These can be used alone or in combination of two or more kinds.

[0062] The macropolyol in the first raw material polyol is preferably a polyester polyol. Examples of polyester polyols include condensation polyester polyols and ring-opening polyester polyols. Examples of condensation polyester polyols include adipate-based polyester polyols and phthalic acid-based polyester polyols. Examples of ring-opening polyester polyols include lactone-based polyester polyols, more specifically polycaprolactone polyols. These can be used alone or in combination of two or more. Examples of polyester polyols include ring-opening polyester polyols, more preferably caprolactone polyols.

[0063] As the low molecular weight polyol in the first raw material polyol, preferably, the above-mentioned dihydric alcohols are used, more preferably, 1,4-butanediol, 1,5-pentanediol and 1,6-hexanediol are used, and even more preferably, 1,6-hexanediol is used.

[0064] In the first raw material polyol, the ratio of the macropolyol to the low molecular weight polyol is not particularly limited and is set appropriately depending on the purpose and application.

[0065] In the isocyanate component for skin, the isocyanate group-terminated prepolymer is obtained by subjecting a first raw material polyisocyanate and a first raw material macropolyol to a urethane reaction (first urethane reaction) at a predetermined equivalent ratio.

[0066] More specifically, the equivalent ratio (NCO / OH) of the isocyanate groups in the first raw material polyisocyanate to the hydroxyl groups in the first raw material macropolyol is, for example, 1.1 or more, preferably 1.4 or more, and more preferably 1.5 or more. Also, the equivalent ratio (NCO / OH) of the isocyanate groups in the first raw material polyisocyanate to the hydroxyl groups in the first raw material macropolyol is, for example, 15.0 or less, preferably 5.0 or less, and more preferably 3.0 or less.

[0067] The reaction temperature is, for example, 20°C or higher, preferably 50°C or higher. The reaction temperature is, for example, 150°C or lower, preferably 120°C or lower. The reaction time is, for example, 0.5 hours or longer, preferably 1 hour or longer. The reaction time is, for example, 18 hours or shorter, preferably 10 hours or shorter.

[0068] As a result, an isocyanate group-terminated prepolymer is obtained as a reaction product liquid in the first urethane-forming reaction.

[0069] In the first urethanization reaction, a known organic solvent can be blended in an appropriate ratio, if necessary. In the first urethanization reaction, a known first urethanization catalyst can be blended in an appropriate ratio, if necessary. Furthermore, after the first urethanization reaction, the organic solvent and / or the urethanization catalyst can be removed by a known method, if necessary. In addition, after the first urethanization reaction, a known organic solvent can be blended in an appropriate ratio, if necessary, to adjust the solids concentration appropriately.

[0070] The isocyanate group content of the isocyanate component for the surface (curing agent) is, for example, 5.0% by mass or more, more preferably 10.0% by mass or more, and more preferably 15.0% by mass or more. The isocyanate group content of the isocyanate component for the surface is, for example, 30.0% by mass or less, preferably 25.0% by mass or less.

[0071] Examples of the active hydrogen group-containing component (main component) for the surface include the macropolyols described above. These can be used alone or in combination of two or more. Preferred examples of the macropolyol include polyurethane polyols.

[0072] The polyurethane polyol is, for example, a reaction product of a second raw material polyisocyanate and a second raw material polyol. Examples of the second raw material polyisocyanate include the polyisocyanate monomers and / or polyisocyanate derivatives described above. These can be used alone or in combination of two or more types.

[0073] As the second raw material polyisocyanate, preferably, a polyisocyanate monomer is used, more preferably, an alicyclic polyisocyanate monomer is used, and even more preferably, isophorone diisocyanate is used.

[0074] Examples of the second raw material polyol include the macropolyols and the low molecular weight polyols described above. These can be used alone or in combination of two or more kinds.

[0075] As the macropolyol in the second raw material polyol, the above-mentioned polyester polyol and polycarbonate polyol are preferred, and polycarbonate polyol is more preferred.

[0076] Examples of polyester polyols include the above-mentioned condensed polyester polyols and the above-mentioned ring-opened polyester polyols.

[0077] Examples of polycarbonate polyols include ring-opening polymers of ethylene carbonate using the above-mentioned low-molecular-weight polyols as initiators. Examples of ring-opening polymers include crystalline polycarbonate polyols. Examples of polycarbonate polyols also include copolymers of the above-mentioned ring-opening polymers with dihydric alcohols having 4 to 6 carbon atoms. Examples of copolymers include amorphous polycarbonate polyols. These can be used alone or in combination of two or more. Examples of polycarbonate polyols include amorphous polycarbonate polyols.

[0078] As the low-molecular-weight polyol in the second raw material polyol, the above-mentioned dihydric alcohols and trihydric alcohols are preferred, and ethylene glycol, 1,4-butanediol and trimethylolpropane are more preferred.

[0079] In the second raw material polyol, the ratio of the macropolyol to the low molecular weight polyol is not particularly limited and is set appropriately depending on the purpose and application.

[0080] In the polyol component for the skin, the polyurethane polyol is obtained by subjecting a second raw material polyisocyanate and a second raw material macropolyol to a urethane reaction (second urethane reaction) at a predetermined equivalent ratio.

[0081] More specifically, the equivalent ratio (OH / NCO) of the hydroxyl groups in the second raw material macro-polyol to the isocyanate groups in the second raw material polyisocyanate is, for example, 1.1 or more, preferably 1.4 or more, and more preferably 1.5 or more. Also, the equivalent ratio (OH / NCO) of the hydroxyl groups in the second raw material macro-polyol to the isocyanate groups in the second raw material polyisocyanate is, for example, 15.0 or less, preferably 10.0 or less, and more preferably 5.0 or less.

[0082] The reaction temperature is, for example, 20°C or higher, preferably 50°C or higher. The reaction temperature is, for example, 150°C or lower, preferably 120°C or lower. The reaction time is, for example, 0.5 hours or longer, preferably 1 hour or longer. The reaction time is, for example, 18 hours or shorter, preferably 10 hours or shorter.

[0083] As a result, a polyurethane polyol is obtained as a reaction product liquid in the second urethanization reaction.

[0084] In the second urethanization reaction, a known organic solvent can be blended in an appropriate ratio, if necessary. In the second urethanization reaction, a known urethanization catalyst can be blended in an appropriate ratio, if necessary. Furthermore, after the second urethanization reaction, the organic solvent and / or the urethanization catalyst can be removed by a known method, if necessary. In addition, after the second urethanization reaction, a known organic solvent can be blended in an appropriate ratio, if necessary, to appropriately adjust the solids concentration.

[0085] The hydroxyl value of the active hydrogen group-containing component for skin (main component) is, for example, 10 mgKOH / g or more, preferably 50 mgKOH / g or more, and, for example, 7000 mgKOH / g or less, preferably 2000 mgKOH / g or less.

[0086] The average number of hydroxyl groups in the active hydrogen group-containing component for epidermis (main component) is, for example, 1.8 or more, preferably 2.0 or more, and the average number of hydroxyl groups in the active hydrogen group-containing component for epidermis (main component) is, for example, 4.0 or less, preferably 3.0 or less.

[0087] In the two-component curing polyurethane composition, the isocyanate component for the surface (curing agent) and the active hydrogen group-containing component for the surface (main component) are appropriately selected and blended in a predetermined ratio so that the 100% modulus of the surface layer 4 (polyurethane resin layer) falls within the range described below.

[0088] As a result, a coating liquid (coating liquid containing polyurethane resin) for forming the surface layer 4 (polyurethane resin layer) is obtained.

[0089] Furthermore, when the surface layer 4 does not have the modulus described below and has the surface roughness described below, the coating liquid containing the polyurethane resin is not limited to the above. For example, the coating liquid containing the polyurethane resin can be obtained as a commercially available product. Furthermore, the coating liquid containing the polyurethane resin can also be obtained as a polyurethane composition containing a known isocyanate component for the surface layer and a known active hydrogen group-containing component for the surface layer.

[0090] The coating liquid may contain additives as needed. Examples of additives include known additives used in coating liquids containing polyurethane resins. More specific examples of additives include antioxidants, UV absorbers, light stabilizers, antifoaming agents, flame retardants, and colorants. The content ratio of the additives is appropriately determined depending on the purpose and application. The additives may be premixed with the isocyanate component for the surface layer and / or the active hydrogen group-containing component for the surface layer. Alternatively, the additives may be blended during blending of the isocyanate component for the surface layer and the active hydrogen group-containing component for the surface layer. Furthermore, the additives may be blended with a mixture of the isocyanate component for the surface layer and the active hydrogen group-containing component for the surface layer.

[0091] The method for forming the skin layer 4 on the surface of the gel layer 3 is not particularly limited, and a known method can be used. For example, first, a coating liquid containing a polyurethane resin is applied to one side of the inner surface of a mold for forming the gel layer 3 (the surface side of the gel layer 3) and cured. This forms the skin layer 4 on the inner surface of the mold. Next, the gel layer 3 is formed using the mold having the skin layer 4 on its inner surface. Thereafter, the gel layer 3 and the skin layer 4 are demolded. This results in the gel layer 3 having the skin layer 4 on its surface. In this case, the gel layer 3 is bonded to the skin layer 4 by the tack of the gel layer 3.

[0092] When the surface layer 4 has a fine uneven structure, the fine uneven structure is made up of a plurality of fine unevennesses. There are no particular limitations on the fine uneven structure, and it can be formed by a known method.

[0093] For example, in the above-described method, a fine concave-convex structure (inverted concave-convex structure) having an inverted pattern to the fine concave-convex structure of the skin layer 4 is formed on the inner surface of a mold in advance. Then, a coating liquid containing a polyurethane resin is applied to the mold having the inverted concave-convex structure and cured. This forms the skin layer 4. At the same time, the inverted concave-convex structure of the mold is transferred to the skin layer 4. As a result, a fine uneven structure is formed on the skin layer 4.

[0094] The method for forming the fine concave-convex structure is not limited to the above. For example, first, a gel layer 3 is formed using a mold that does not have a skin layer 4. Then, a coating liquid containing a polyurethane resin is applied to the surface of the gel layer 3. Then, the film having the inverted concave-convex structure is pressed against a coating of a polyurethane resin solution and / or dispersion. In this state, the coating of the coating liquid is cured. This forms the skin layer 4, and the inverted concave-convex structure of the film is transferred to the skin layer 4. As a result, a fine concave-convex structure is formed on the skin layer 4.

[0095] When the surface of the skin layer 4 does not have a fine uneven structure, the skin layer 4 is formed using, for example, a mold that does not have an inverted uneven structure.

[0096] The skin layer 4 has a predetermined modulus (A) and / or a predetermined surface roughness (B).

[0097] For example, when the skin layer 4 has a predetermined modulus (A), the 100% modulus of the skin layer 4 is 5.0 MPa or less, preferably 4.5 MPa or less, more preferably 4.0 MPa or less, even more preferably 3.5 MPa or less, and particularly preferably 3.4 MPa or less. The 100% modulus of the skin layer 4 is, for example, 0.1 MPa or more, preferably 0.5 MPa or more, more preferably 1.0 MPa or more, even more preferably 1.5 MPa or more, and particularly preferably 2.0 MPa or more. The 100% modulus is the stress value at an elongation rate of 100%. The 100% modulus is measured according to the examples described later. When the 100% modulus of the skin layer 4 is below the upper limit, a particularly excellent feel can be obtained.

[0098] When the skin layer 4 has the above-mentioned predetermined modulus (A), the surface of the skin layer 4 does not necessarily have a microrelief structure. Preferably, the surface of the skin layer 4 has a microrelief structure. In such a case, the surface roughness of the skin layer 4 is not particularly limited and is appropriately set depending on the purpose and application. For example, the arithmetic mean roughness Ra of the surface of the skin layer 4 is, for example, 10 μm or less, preferably 8.0 μm or less, more preferably 6.0 μm or less, even more preferably 5.0 μm or less, and particularly preferably 4.0 μm or less. The arithmetic mean roughness Ra of the surface of the skin layer 4 is, for example, greater than 0 μm, preferably 0.10 μm or more, preferably 0.5 μm or more, more preferably 1.0 μm or more, and even more preferably 1.5 μm or more. The arithmetic mean roughness Ra is measured according to the examples described below. The measurement conditions described below are also employed.

[0099] On the other hand, for example, when the skin layer 4 has a predetermined surface roughness (B), the arithmetic mean roughness Ra of the surface of the skin layer 4 is 10 μm or less, preferably 8.0 μm or less, more preferably 6.0 μm or less, even more preferably 5.0 μm or less, and particularly preferably 4.0 μm or less. The arithmetic mean roughness Ra of the surface of the skin layer 4 exceeds 0 μm, preferably 0.10 μm or more, preferably 0.5 μm or more, more preferably 1.0 μm or more, and even more preferably 1.5 μm or more. The arithmetic mean roughness Ra is measured in accordance with the examples described later. The following measurement conditions are adopted.

[0100] Arithmetic mean roughness Ra measurement conditions: spherical φ1.6 mm contact, specified load 0.4 gf, measurement length 40 mm, cutoff wavelength 0.8 mm, measurement speed 0.15 mm / sec

[0101] When the skin layer 4 has the predetermined surface roughness (B), the modulus of the skin layer 4 is not particularly limited and may be appropriately set depending on the purpose and application. For example, the 100% modulus of the skin layer 4 is, for example, 15.0 MPa or less, preferably 10.0 MPa or less, and more preferably 7.0 MPa or less. The 100% modulus of the skin layer 4 is, for example, 0.1 MPa or more, preferably 0.5 MPa or more, more preferably 1.0 MPa or more, even more preferably 1.5 MPa or more, and particularly preferably 2.0 MPa or more. The 100% modulus is the stress value at an elongation rate of 100%. In particular, even if the 100% modulus of the skin layer 4 is relatively high (for example, exceeding 5.0 MPa), an excellent tactile feel can be obtained as long as the modulus of the surface of the skin layer 4 is within the above range.

[0102] Storage modulus (E') of the epidermis layer 4 at 23°C coat The storage modulus (E') of the skin layer 4 at 23°C is, for example, 1 MPa or more, preferably 3 MPa or more, more preferably 5 MPa or more, and even more preferably 10 MPa or more. coat) is, for example, 100 MPa or less, preferably 70 MPa or less, more preferably 50 MPa or less, even more preferably 30 MPa or less, and particularly preferably 20 MPa or less.

[0103] The storage modulus (E') of the gel layer 3 at 23°C gel ) to the storage modulus (E') of the skin layer 4 at 23°C coat ) ratio (E' coat / E' gel ) is, for example, 0.1 or more, preferably 1 or more, more preferably 10 or more, and even more preferably 50 or more. In addition, the storage modulus (E' gel ) to the storage modulus (E') of the skin layer 4 at 23°C coat ) ratio (E' coat / E' gel ) is, for example, 2000 or less, preferably 1000 or less, more preferably 500 or less, and even more preferably 300 or less.

[0104] The storage modulus (E') of gel layer 3 at 23°C gel ) to the storage modulus (E') of the skin layer 4 at 23°C coat ) ratio (E' coat / E' gel ) is within the above range, a cushioning material 1 with a more excellent feel can be obtained.

[0105] From the viewpoint of obtaining a better feel, the average thickness of the skin layer 4 is, for example, 1 μm or more, preferably 10 μm or more, more preferably 20 μm or more, even more preferably 50 μm or more, and particularly preferably 70 μm or more. From the viewpoint of obtaining a better feel, the average thickness of the skin layer 4 is, for example, 2000 μm or less, preferably 1000 μm or less, more preferably 700 μm or less, even more preferably 300 μm or less, and particularly preferably 150 μm or less.

[0106] The ratio of the average thickness of the skin layer 4 to the average thickness of the gel layer 3 (average thickness of the skin layer 4 / average thickness of the gel layer 3) is, for example, 0.0001 or more, preferably 0.001 or more. The ratio of the average thickness of the skin layer 4 to the average thickness of the gel layer 3 (average thickness of the skin layer 4 / average thickness of the gel layer 3) is, for example, 1 or less, preferably 0.1 or less. When the average thickness ratio is within the above range, a cushioning material 1 with an even more excellent feel can be obtained.

[0107] The cushioning material 1 can further include a foam layer 5. The foam layer 5 is disposed in contact with the gel layer 3, for example, on the other side of the gel layer 3. In other words, the foam layer 5 is laminated on the opposite side of the gel layer 3 from the skin layer 4. That is, the foam layer 5 is laminated on the gel layer 3 on the back side of the gel layer 3 (the lower side of the paper).

[0108] The foam layer 5 may be made of, for example, a known foam, preferably a polyurethane foam. The foam layer 5 is more preferably made of a polyurethane foam. The polyurethane foam provides excellent elasticity.

[0109] More specifically, the polyurethane foam includes polyurethane foam and foamed elastomer. The polyurethane foam preferably includes polyurethane foam. The polyurethane foam includes flexible foam and rigid foam.

[0110] Flexible foams and rigid foams are distinguished by their hardness. The Asker F hardness of flexible foams is, for example, 1 or more, preferably 10 or more. The Asker F hardness of flexible foams is, for example, 90 or less, preferably 70 or less. The Asker F hardness of rigid foams is, for example, more than 90. Preferred examples of polyurethane foams include flexible foams.

[0111] The polyurethane foam can be obtained, for example, as a commercially available product.

[0112] The storage modulus (E') of the foam layer 5 at 23°C foam The storage modulus (E') of the foam layer 5 at 23°C is, for example, 0.01 MPa or more, preferably 0.03 MPa or more, more preferably 0.05 MPa or more, and even more preferably 0.10 MPa or more. foam ) is, for example, 5.0 MPa or less, preferably 1.0 MPa or less, more preferably 0.8 MPa or less, even more preferably 0.5 MPa or less, and particularly preferably 0.3 MPa or less.

[0113] The storage modulus (E') of the foam layer 5 at 23°C foam ) to the storage modulus (E') of the skin layer 4 at 23°C coat ) ratio (E' coat / E' foam ) is, for example, 0.1 or more, preferably 1.0 or more, more preferably 10 or more, and even more preferably 50 or more. In addition, the storage modulus (E') of the foam layer 5 at 23°C foam ) to the storage modulus (E') of the skin layer 4 at 23°C coat ) ratio (E' coat / E' foam ) is, for example, 2000 or less, preferably 1000 or less, more preferably 500 or less, even more preferably 300 or less, and particularly preferably 200 or less.

[0114] The storage modulus (E') of the foam layer 5 at 23°C foam ) to the storage modulus (E') of the gel layer 3 at 23 ° C. gel ) ratio (E' gel / E' foam The storage modulus (E') of the foam layer 5 at 23°C is 0.1 or more, preferably 0.2 or more, more preferably 0.4 or more, and even more preferably 0.8 or more. foam ) to the storage modulus (E') of the gel layer 3 at 23 ° C. gel ) ratio (E' gel / E' foam ) is less than 10, preferably 5 or less, more preferably 3 or less, and even more preferably 2 or less.

[0115] The average thickness of the foam layer 5 is set depending on the type of mold, etc. From the viewpoint of obtaining a better feel, the average thickness of the foam layer 5 is, for example, 500 μm or more, preferably 1000 μm or more, more preferably 5000 μm or more. From the viewpoint of obtaining a better feel, the average thickness of the foam layer 5 is, for example, 50000 μm or less, preferably 20000 μm or less, more preferably 15000 μm or less.

[0116] The ratio of the average thickness of the foam layer 5 to the average thickness of the gel layer 3 (average thickness of the foam layer 5 / average thickness of the gel layer 3) is, for example, 0.1 or more, or preferably 1 or more. The ratio of the average thickness of the foam layer 5 to the average thickness of the gel layer 3 (average thickness of the foam layer 5 / average thickness of the gel layer 3) is, for example, 40 or less, or preferably 10 or less.

[0117] In addition, the density of the foam layer 5 is set to, for example, 10 kg / m from the viewpoint of obtaining a better feel. 3 More than 50 kg / m 3 More preferably, 80 kg / m 3 The density of the foam layer 5 is set to, for example, 500 kg / m from the viewpoint of obtaining a better feel. 3 Preferably, 200 kg / m or less 3 or less, more preferably 150 kg / m 3 The following is the result.

[0118] The foam layer 5 is bonded to the gel layer 3, for example, by a known method. For example, the gel layer 3 is bonded to the foam layer 5 by tack of the gel layer 3. Alternatively, for example, the gel layer 3 is bonded to the foam layer 5 via a known adhesive. Preferably, the gel layer 3 is bonded to the foam layer 5 by tack of the gel layer 3.

[0119] The cushioning material includes a gel layer having a predetermined storage modulus and a skin layer disposed on one side of the gel layer. The 100% modulus of the skin layer is below a predetermined value, and / or the skin layer has a micro-convexo-concave structure on its surface, and the arithmetic mean roughness Ra of the surface of the skin layer is below a predetermined value. Therefore, the cushioning material, exterior material, and robot component of the present invention have an excellent tactile feel.

[0120] Therefore, the cushioning material 1 is suitably used in, for example, various industrial fields. Examples of industrial fields include the exterior material field. Exterior materials are components attached to the exterior of various living organisms and / or products. More specifically, the exterior material field includes the furniture field, the automated exercise equipment field (robot field), and the sports field. Applications of the cushioning material 1 in the furniture field include, for example, furniture corner guards, cushioned carpets, and anti-collision cushions. Applications of the cushioning material 1 in the robot field include, for example, cushioning for factory robots, cushioning for building maintenance robots, cushioning for personal guidance robots, cushioning for communication robots, and cushioning for nursing care robots. Applications of the cushioning material 1 in the sports field include, for example, protectors for ball games and martial arts. Because the cushioning material 1 has an excellent tactile feel, it is particularly preferably used in the automated exercise equipment field (robot field). That is, the cushioning material is particularly preferably used as a cushioning for robots.

[0121] That is, the above-mentioned cushioning material is preferably included in an exterior material, and more preferably included in a robot part. The robot part includes, for example, a mechanical part of the robot (e.g., a robot arm) and the above-mentioned cushioning material covering the mechanical part. Such a robot part includes a gel layer having a predetermined storage modulus and a skin layer disposed on one side of the gel layer. The 100% modulus of the skin layer is below a predetermined value. Therefore, the above-mentioned exterior material and robot part have an excellent tactile feel.

[0122] As a result, the above robot parts are particularly suitable for use as parts for robots that work collaboratively with humans (collaborative robots).

[0123] In FIG. 1, the gel layer 3 is formed only on the surface of the foam layer 5. In FIG. 1, the skin layer 4 is formed only on the surface of the gel layer 3. However, for example, the gel layer 3 may be formed on the front, back, and side surfaces of the foam layer 5. In addition, for example, the skin layer 4 may be formed on the front and side surfaces of the gel layer 3. In addition, the gel layer 3 and the skin layer 4 may be formed on the front and back surfaces of the foam layer 5, but not on the side surfaces of the foam layer 5. [Example]

[0124] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Note that "parts" and "%" are by mass unless otherwise specified. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, and parameters used in the following description can be substituted with the corresponding upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or more than" or "exceeding") of the blending ratios (content ratios), physical property values, parameters, etc. described in the above "Form for Carrying Out the Invention."

[0125] [First embodiment (modulus)] Synthesis Example 1 Isocyanate component for surface (isocyanate group-terminated prepolymer (A1)) A reactor equipped with a thermometer, stirrer, nitrogen inlet, and condenser was charged with 500 parts by mass of hexamethylene diisocyanate (HDI, manufactured by Mitsui Chemicals, Inc., product name: Takenate 700), 0.25 parts by mass of 2,6-di(tert-butyl)-4-methylphenol (also known as dibutylhydroxytoluene, BHT, a hindered phenol-based antioxidant), and 0.25 parts by mass of tetraphenyl dipropylene glycol diphosphite (an organic phosphite ester, a cocatalyst) under a nitrogen atmosphere and mixed. To the resulting mixture, 10.7 parts by mass of 1,3-butanediol was added, and nitrogen was introduced for 1 hour. The mixture was then heated to 80°C and reacted for 3 hours. The mixture was then cooled to 60°C. Next, 0.2 parts by mass of trimethyl-N-2-hydroxypropylammonium 2-ethylhexanoate (isocyanurate catalyst) was added to the mixture, and the mixture was allowed to react for 1.5 hours. Furthermore, 0.05 parts by mass of o-toluenesulfonamide was added to the mixture. The mixture was then distilled using a thin-film distillation apparatus (temperature 150°C, vacuum degree 93.3 Pa) to adjust the amount of residual HDI monomer to 1.0% or less.

[0126] As a result, an isocyanurate derivative of hexamethylene diisocyanate was obtained as the first raw material polyisocyanate. The isocyanurate derivative had an isocyanate group content of 20.7 mass % and an average isocyanate number of 3.4.

[0127] In addition, 1000 parts by mass of caprolactone diol (manufactured by Daicel Corporation, trade name: Placcel 210) and 33 parts by mass of 1,6-hexanediol were added to a reactor equipped with a thermometer, a stirrer, a nitrogen inlet pipe, and a cooling pipe under a nitrogen atmosphere, and then mixed to obtain a first raw material polyol.

[0128] The first raw material polyol was maintained at 80°C in the reactor. Next, 914 parts by mass of the first raw material polyisocyanate was added little by little to the reactor. The temperature in the reactor was maintained at 85°C or lower. After the addition, the temperature in the reactor was maintained at 80±5°C, and the first raw material polyisocyanate and the first raw material polyol were reacted for 5 hours. The equivalent ratio (NCO / OH) of the isocyanate groups in the first raw material polyisocyanate to the hydroxyl groups in the first raw material macropolyol was 1.76.

[0129] This gave an isocyanate group-terminated prepolymer (A1) as an isocyanate component for the surface layer.

[0130] Synthesis Example 2 Polyol component for skin (polyurethane polyol (B1)) Into a reactor equipped with a thermometer, a stirrer, a nitrogen inlet pipe, and a cooling pipe, 266 parts by mass of 1,6-hexamethylene carbonate diol (second raw material polyol, polycarbonate polyol using 1,6-hexanediol as an initiator, manufactured by Asahi Kasei Corporation, product name Duranol T6001) was added under a nitrogen atmosphere, and the temperature inside the reactor was maintained at 80°C.

[0131] Next, 13.8 parts by mass of isophorone diisocyanate (second raw material polyisocyanate) was added little by little to the reactor. The temperature inside the reactor was maintained at 85°C or less. After the addition, the temperature inside the reactor was maintained at 80±5°C, and the second raw material polyisocyanate and the second raw material polyol were reacted for 5 hours. The equivalent ratio (OH / NCO) of the hydroxyl groups in the second raw material macropolyol to the isocyanate groups in the second raw material polyisocyanate was 4.3.

[0132] Next, the temperature of the reaction product liquid was lowered to 50° C. Thereafter, 594 parts by mass of methyl isobutyl ketone, 81 parts by mass of methyl ethyl ketone, and 45 parts by mass of toluene were added to the reaction product liquid.

[0133] This gave polyurethane polyol (B1) as a polyol component for the skin.

[0134] Synthesis Example 3 Polyol component for skin (polyurethane polyol (B2)) In a reactor equipped with a thermometer, a stirrer, a nitrogen inlet pipe, and a cooling pipe, 246 parts by mass of caprolactone diol (second raw material polyol, product of Daicel Corporation, trade name Placcel 210), 0.6 parts by mass of ethylene glycol, 9 parts by mass of 1,4-butanediol, and 3.7 parts by mass of trimethylolpropane were mixed under a nitrogen atmosphere, and the temperature inside the reactor was maintained at 80°C.

[0135] Next, 20.4 parts by mass of isophorone diisocyanate (second raw material polyisocyanate) was added little by little to the reactor. The temperature inside the reactor was maintained at 85°C or lower. After the addition, the temperature inside the reactor was maintained at 80±5°C, and the second raw material polyisocyanate and the second raw material polyol were reacted for 5 hours. The equivalent ratio (OH / NCO) of hydroxyl groups in the second raw material macropolyol to isocyanate groups in the second raw material polyisocyanate was 4.2.

[0136] Next, the temperature of the reaction product liquid was lowered to 50° C. Thereafter, 205 parts by mass of methyl isobutyl ketone, 185 parts by mass of methyl ethyl ketone, and 330 parts by mass of toluene were added to the reaction product liquid.

[0137] This gave polyurethane polyol (B2) as a polyol component for the skin.

[0138] Example 1 (1) Mold concave / convex processing A mold with inner dimensions of 120 mm x 120 mm x 2 mm was prepared. One side of the inner surface of the mold was subjected to a matte finish. In other words, a fine uneven structure was formed on one side of the inner surface of the mold. The arithmetic mean roughness Ra of one side of the inner surface of the mold was measured in accordance with JIS B 0601 (2001) using the method and conditions described below. The arithmetic mean roughness Ra of one side of the inner surface of the mold was 10 μm.

[0139] (2) Epidermal layer A coating liquid was obtained by mixing 100 parts by mass of polyurethane polyol (B1) as a polyol component (main component) for the surface layer, 5 parts by mass of isocyanate group-terminated prepolymer (A1) as an isocyanate component (curing agent) for the surface layer, and 150 parts by mass of a mixed solvent (50 parts by mass of methyl ethyl ketone, 50 parts by mass of ethyl acetate).

[0140] The coating liquid was applied to one side of the inner surface of the mold and dried. This resulted in a surface layer made of polyurethane resin. The film thickness was adjusted by the number of times the coating was applied. The fine uneven structure of the mold was transferred to the surface layer. In other words, a fine uneven structure was formed on the surface layer. The average thickness of the surface layer was 100 μm. The arithmetic mean roughness Ra of the surface layer was measured using the method and conditions described below. The arithmetic mean roughness Ra of the surface layer was 3.6 μm.

[0141] (3) Gel layer The following components were mixed using a three-one motor to obtain a resin premix. PTXG-1800 (polytetramethylene ether polyol, copolymer of tetrahydrofuran and neopentyl glycol, amorphous polytetramethylene ether glycol, number average molecular weight 1800, average hydroxyl value 60 mgKOH / g, average functionality 2, manufactured by Asahi Kasei) 100 parts by mass Hexamol DINCH (plasticizer, hydrogenated diisononyl phthalate, manufactured by BASF Japan) 127.15 parts by mass Dibutyltin dilaurate (urethane catalyst, dibutyltin(IV) dilaurate, Tokyo Chemical Industry Co., Ltd.) 0.024 parts by mass BYK-088 (antifoaming agent, silicone surfactant, manufactured by BYK Japan) 0.24 parts by mass

[0142] Next, the following components were stirred with a three-one motor and degassed under vacuum to obtain a mixture. 100 parts by mass of the above resin premix 4.66 parts by mass of Stabio D-370N (an isocyanurate derivative of pentamethylene diisocyanate, manufactured by Mitsui Chemicals) Equivalent ratio (NCO / active hydrogen group): 0.583

[0143] 28.8 g of the mixture was poured into the mold with the skin layer formed thereon, taking care to avoid bubbles, and cured in an oven at 80°C for 1 hour. The molded product was then demolded to obtain a polyurethane gel with a skin. The average thickness of the gel layer was 2000 μm.

[0144] (4) Foam layer Tera Venus WS (trade name, manufactured by Yukigaya Chemical Industry Co., Ltd., average thickness 10 mm (10000 μm)) was prepared as a polyurethane foam. This was used as a foam layer.

[0145] (5) Cushioning material The polyurethane gel with skin and the foam layer were bonded together by tack of the gel layer, thereby obtaining a cushioning material comprising a foam layer, a gel layer, and a skin layer.

[0146] Example 2 Polyurethane polyol (B2) was used instead of polyurethane polyol (B1). A cushioning material was obtained in the same manner as in Example 1 except for this. The average thickness of the skin layer was 100 μm. The arithmetic mean roughness Ra of the skin layer was measured by the method and conditions described below. The arithmetic mean roughness Ra of the skin layer was 5.91 μm.

[0147] Comparative Example 1 The coating liquid used was commercially available FORTIMO XSP-659 (bis(isocyanatomethyl)cyclohexane solution, solids concentration 16%, manufactured by Mitsui Chemicals). Aside from this, a buffer material was obtained in the same manner as in Example 1. The average thickness of the skin layer was 100 μm. The arithmetic mean roughness Ra of the skin layer was measured using the method and conditions described below. The arithmetic mean roughness Ra of the skin layer was 5.3 μm.

[0148] <Physical properties> (1) Storage modulus Storage modulus (E') of the gel layer of the buffer material gel ) and the storage modulus of the foam layer (E' foam) was calculated in the following way.

[0149] That is, the temperature dependence of the dynamic viscoelasticity of the gel layer was measured using a dynamic viscoelasticity device (IT Measurement and Control Co., Ltd., Model: DVA-200) under the conditions of tension mode, frequency of 10 Hz, and temperature rise rate of 5°C / min, and the storage modulus at 23°C was defined as the storage modulus of the gel layer (E' gel ) was decided.

[0150] In addition, the temperature dependence of the dynamic viscoelasticity of a sample cut out to 20 mm x 20 mm x 10 mm from the core of the foam layer was measured using a dynamic viscoelasticity device (IT Measurement & Control Co., Ltd., Model: DVA-220) under conditions of compression mode, frequency of 10 Hz, and temperature rise rate of 5 °C / min. The storage modulus at 23 °C was calculated as the storage modulus of the gel layer (E' gel ) was decided.

[0151] In addition, the storage modulus of the epidermis (E' coat ) was determined in the same manner as for the gel layer.

[0152] (2) 100% modulus The coating liquid containing the polyurethane resin was dried to obtain a skin sample having an average thickness of 0.04 mm. Note that the skin sample did not have a microrelief structure formed on it.

[0153] Next, the stress value (tensile strength) of the skin sample at 100% elongation was measured in accordance with the tensile test method described in JIS K 7312 (1996). This tensile strength was defined as the 100% modulus of the skin layer. The tensile tester used was an RTG-1310 (manufactured by A&D Co., Ltd.). A No. 3 dumbbell was used as the test specimen. The tensile speed was 100 mm / min.

[0154] (3) Arithmetic mean roughness Ra of the surface The arithmetic mean roughness Ra of the surface of the skin layer of the cushioning material was determined by the following method: The arithmetic mean roughness Ra of the inner surface of the mold was determined by the following method.

[0155] That is, the arithmetic mean roughness Ra was measured using a surface roughness measuring instrument (surface roughness and shape measuring instrument Surfcom 1400D, manufactured by Tokyo Seimitsu Co., Ltd.) The measurement conditions were set as follows:

[0156] Measurement conditions for the arithmetic mean roughness Ra of the surface layer: spherical φ1.6 mm contact, specified load 0.4 gf, measurement length 40 mm, cutoff wavelength 0.8 mm, measurement speed 0.15 mm / sec

[0157] Measurement conditions for the arithmetic mean roughness Ra of the inner surface of the mold: spherical φ1.6 mm contact, specified load 0.4 gf, measurement length 40 mm, cutoff wavelength 8 mm, measurement speed 0.15 mm / sec

[0158] <Evaluation> (1) Friction test The coefficient of dynamic friction of the surface of the skin layer of the cushioning material was measured using a touch meter equipped with a handy probe (TripoGear Type 33, manufactured by Shinto Scientific Co., Ltd.) under the following measurement conditions:

[0159] Handy probe tip size: φ12mm, measurement load: 20gf, no sliding speed setting

[0160] (2) Touch test The index finger was slid across the surface of the surface layer of the cushioning material, and the smoothness of the sliding was evaluated according to the following criteria.

[0161] ○: No unevenness is felt. Fingers slide easily. △: Feels a little uneven. Fingers slip easily. ×: Feels uneven. Fingers do not slide easily.

[0162] [Table 1]

[0163] [Second embodiment (surface roughness)] Example 3 (1) Mold concave / convex processing A mold with inner dimensions of 120 mm x 120 mm x 2 mm was prepared. One side of the inner surface of the mold was subjected to a matte finish. In other words, a fine uneven structure was formed on one side of the inner surface of the mold. The arithmetic mean roughness Ra of one side of the inner surface of the mold was measured in accordance with JIS B 0601 (2001) using the method and conditions described below. The arithmetic mean roughness Ra of one side of the inner surface of the mold was 3.5 μm.

[0164] (2) Epidermal layer Fortimo XSP-659 (bis(isocyanatomethyl)cyclohexane solution, solid content concentration 16%, manufactured by Mitsui Chemicals) was prepared as a coating liquid containing a polyurethane resin.

[0165] The coating solution was applied to one side of the inner surface of the mold and dried. This resulted in a surface layer made of polyurethane resin. The fine unevenness of the mold was also transferred to the surface layer. That is, a fine uneven structure was formed on the surface layer. The average thickness of the surface layer was 100 μm. The arithmetic mean roughness Ra of the surface layer was measured by the method and conditions described below. The arithmetic mean roughness Ra of the surface layer was 1.5 μm.

[0166] (3) Gel layer The following components were mixed using a three-one motor to obtain a resin premix. PTXG-1800 (polytetramethylene ether polyol, copolymer of tetrahydrofuran and neopentyl glycol, amorphous polytetramethylene ether glycol, number average molecular weight 1800, average hydroxyl value 60 mgKOH / g, average functionality 2, manufactured by Asahi Kasei) 100 parts by mass Hexamol DINCH (plasticizer, hydrogenated diisononyl phthalate, manufactured by BASF Japan) 127.15 parts by mass Dibutyltin dilaurate (urethane catalyst, dibutyltin(IV) dilaurate, Tokyo Chemical Industry Co., Ltd.) 0.024 parts by mass BYK-088 (antifoaming agent, silicone surfactant, manufactured by BYK Japan) 0.24 parts by mass

[0167] Next, the following components were stirred with a three-one motor and degassed under vacuum to obtain a mixture. 100 parts by mass of the above resin premix 4.66 parts by mass of Stabio D-370N (an isocyanurate derivative of pentamethylene diisocyanate, manufactured by Mitsui Chemicals) Equivalent ratio (NCO / active hydrogen group): 0.583

[0168] 28.8 g of the mixture was poured into the mold with the skin layer formed thereon, taking care to avoid bubbles, and cured in an oven at 80°C for 1 hour. The molded product was then demolded to obtain a polyurethane gel with a skin. The average thickness of the gel layer was 2000 μm.

[0169] (4) Foam layer Tera Venus WS (trade name, manufactured by Yukigaya Chemical Industry Co., Ltd., average thickness 10 mm (10000 μm)) was prepared as a polyurethane foam. This was used as a foam layer.

[0170] (5) Cushioning material The polyurethane gel with skin and the foam layer were bonded together by tack of the gel layer, thereby obtaining a cushioning material comprising a foam layer, a gel layer, and a skin layer.

[0171] Example 4 In the uneven processing of the mold, the arithmetic mean roughness Ra of the inner surface of the mold was adjusted to 7.0 μm. Except for this, a cushioning material was obtained in the same manner as in Example 3. The arithmetic mean roughness Ra of the skin layer was measured using the method and conditions described below. The arithmetic mean roughness Ra of the skin layer was 3.6 μm.

[0172] Example 5 In the uneven processing of the mold, the arithmetic mean roughness Ra of the inner surface of the mold was adjusted to 10.0 μm. Except for this, the cushioning material was obtained in the same manner as in Example 3. The arithmetic mean roughness Ra of the skin layer was measured using the method and conditions described below. The arithmetic mean roughness Ra of the skin layer was 5.3 μm.

[0173] Comparative Example 2 The inner surface of the mold was not textured, and other than this, a cushioning material was obtained in the same manner as in Example 3.

[0174] <Physical properties> (1) Storage modulus Storage modulus of the gel layer of the buffer material (E' gel ) and the storage modulus of the foam layer (E' foam ) was calculated in the following way.

[0175] That is, the temperature dependence of the dynamic viscoelasticity of the gel layer was measured using a dynamic viscoelasticity device (IT Measurement and Control Co., Ltd., Model: DVA-200) under the conditions of tension mode, frequency of 10 Hz, and temperature rise rate of 5°C / min, and the storage modulus at 23°C was defined as the storage modulus of the gel layer (E' gel ) was decided.

[0176] In addition, the temperature dependence of the dynamic viscoelasticity of a sample cut out to 20 mm x 20 mm x 10 mm from the core of the foam layer was measured using a dynamic viscoelasticity device (IT Measurement & Control Co., Ltd., Model: DVA-220) under conditions of compression mode, frequency of 10 Hz, and temperature rise rate of 5 °C / min. The storage modulus at 23 °C was calculated as the storage modulus of the gel layer (E' gel ) was decided.

[0177] In addition, the storage modulus of the epidermis (E' coat ) was determined in the same manner as for the gel layer.

[0178] (2) Arithmetic mean roughness Ra of the surface The arithmetic mean roughness Ra of the surface of the skin layer of the cushioning material was determined by the following method: The arithmetic mean roughness Ra of the inner surface of the mold was determined by the following method.

[0179] That is, the arithmetic mean roughness Ra was measured using a surface roughness measuring instrument (surface roughness and shape measuring instrument Surfcom 1400D, manufactured by Tokyo Seimitsu Co., Ltd.) The measurement conditions were set as follows:

[0180] Measurement conditions for the arithmetic mean roughness Ra of the surface layer: spherical φ1.6 mm contact, specified load 0.4 gf, measurement length 40 mm, cutoff wavelength 0.8 mm, measurement speed 0.15 mm / sec

[0181] Measurement conditions for the arithmetic mean roughness Ra of the inner surface of the mold: spherical φ1.6 mm contact, specified load 0.4 gf, measurement length 40 mm, cutoff wavelength 8 mm, measurement speed 0.15 mm / sec

[0182] <Evaluation> (1) Friction test The coefficient of dynamic friction of the surface of the skin layer of the cushioning material was measured using a touch meter equipped with a handy probe (TripoGear Type 33, manufactured by Shinto Scientific Co., Ltd.) under the following measurement conditions:

[0183] Handy probe tip size: φ12mm, measurement load: 20gf, no sliding speed setting

[0184] (2) Touch test The index finger was slid across the surface of the surface layer of the cushioning material, and the smoothness of the sliding was evaluated according to the following criteria.

[0185] ○: No unevenness is felt. Fingers slide easily. △: Feels uneven. Fingers do not slide easily. ×: I feel unevenness. My fingers barely slip.

[0186] [Table 2] [Explanation of symbols]

[0187] 1 Cushioning material 2 Polyurethane gel with skin 3 Gel layer 4 Epidermal layer 5 Foam layer

Claims

1. A cushioning material comprising a gel layer and a surface layer, the gel layer comprises a polyurethane gel; The storage modulus (E') of the gel layer at 23°C ｇｅｌ ) is 0.01 MPa or more and 10 MPa or less, the epidermis layer is disposed on one side of the gel layer; The 100% modulus of the skin layer is 5.0 MPa or less. and / or the surface of the skin layer has a fine uneven structure, and the arithmetic mean roughness Ra of the surface of the skin layer, measured under the following conditions, is greater than 0 μm and 10 μm or less; The cushioning material further comprises a foam layer, the foam layer is disposed on the other side of the gel layer, the other side being opposite the one side; The average thickness of the foam layer is 1,000 μm or more and 50,000 μm or less, The buffer material, wherein the average thickness of the gel layer is 500 μm or more and 10,000 μm or less. Arithmetic mean roughness Ra measurement conditions: spherical φ1.6 mm contact, specified load 0.4 gf, measurement length 40 mm, cutoff wavelength 0.8 mm, measurement speed 0.15 mm / sec

2. 2. The cushioning material according to claim 1, wherein the average thickness of the surface layer is 10 μm or more and 1000 μm or less.

3. The density of the foam layer is 80 kg / m ３ More than 200kg / m ３ is as follows: The density of the gel layer is 500 kg / m ３ More than 1200kg / m ３ 2. The cushioning material according to claim 1, wherein:

4. An exterior material comprising the cushioning material according to claim 1.

5. A robot component comprising the cushioning material of claim 1.

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