Polyurethane viscoelastic material

Abstract

To provide a polyurethane viscoelastic body having excellent tensile characteristics and high viscosity.SOLUTION: A polyurethane viscoelastic body contains a product from the reaction between a polyisocyanate component containing a derivative of aliphatic polyisocyanate and a polyol component containing polycarbonate polyol and / or aromatic ring-containing polyester polyol. The polyol component has a hydroxyl value of 120 mgKOH / g or more and 300 mgKOH / g or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyurethane viscoelastic material. [Background technology]

[0002] Conventionally, polyurethane has been used in the fields of shock absorbing members and buffer members.

[0003] As such polyurethane, for example, a polyurethane gel comprising a gel layer and a coating layer that covers the gel layer has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 010422 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] However, the polyurethane gel of Patent Document 1 is an elastic body with low viscosity. Therefore, when a force is applied to such a polyurethane gel to deform it, and then the force is removed, the deformation returns to its original state immediately.

[0006] On the other hand, depending on the purpose and application, a highly viscous elastic material is required. When a highly viscous elastic material is deformed by applying a force and then the force is removed, the deformation returns slowly, improving impact resistance.

[0007] Furthermore, such elastic bodies are required to have improved tensile properties (tensile strength, tensile elongation).

[0008] The present invention provides a polyurethane viscoelastic material that has excellent tensile properties and high viscosity. [Means for solving the problem]

[0009] The present invention [1] is a polyurethane viscoelastic body comprising a reaction product of a polyisocyanate component containing a derivative of an aliphatic polyisocyanate and a polyol component containing a polycarbonate polyol and / or an aromatic ring-containing polyester polyol, wherein the hydroxyl value of the polyol component is 120 mgKOH / g or more and 300 mgKOH / g or less.

[0010] The present invention [2] includes the polyurethane viscoelastic material according to the above [1], in which the average number of functional groups of the aliphatic polyisocyanate derivative is more than 2 and less than 4.

[0011] The present invention [3] includes the polyurethane viscoelastic material according to the above [1] or [2], in which the derivative of the aliphatic polyisocyanate is an allophanate-isocyanurate derivative.

[0012] The present invention [4] includes the polyurethane viscoelastic material according to any one of the above [1] to [3], which has a plant-based content of 40% or more. [Effects of the Invention]

[0013] The polyurethane viscoelastic material of the present invention contains a reaction product of a polyisocyanate component containing an aliphatic polyisocyanate derivative and a polyol component containing a polycarbonate polyol and / or an aromatic ring-containing polyester polyol. The polyol component has a predetermined hydroxyl value. This improves tensile properties and increases viscosity. DETAILED DESCRIPTION OF THE INVENTION

[0014] The polyurethane viscoelastic comprises the reaction product of a polyisocyanate component and a polyol component.

[0015] <Polyisocyanate component> The polyisocyanate component includes derivatives of aliphatic polyisocyanates.

[0016] [Aliphatic polyisocyanate derivatives] In the derivatives of aliphatic polyisocyanates, examples of the aliphatic polyisocyanates (monomers of aliphatic polyisocyanates) include aliphatic diisocyanates.

[0017] Aliphatic diisocyanates include, for example, 1,6-hexamethylene diisocyanate (1,6-HDI), 1,5-pentamethylene diisocyanate (1,5-PDI), tetramethylene diisocyanate, trimethylene diisocyanate, 1,2-, 2,3-, or 1,3-butylene diisocyanate, and 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate.

[0018] Furthermore, examples of the aliphatic polyisocyanate include alicyclic polyisocyanates, and examples of the alicyclic polyisocyanates include alicyclic diisocyanates.

[0019] Examples of alicyclic diisocyanates include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'-, 2,4'-, or 2,2'-methylenebis(cyclohexyl isocyanate), or mixtures thereof (H 12 MDI), 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane or a mixture thereof (H6XDI), bis(isocyanatomethyl)norbornane (NBDI), 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, and methyl-2,6-cyclohexane diisocyanate.

[0020] The aliphatic polyisocyanate is preferably an aliphatic diisocyanate, more preferably 1,6-hexamethylene diisocyanate and 1,5-pentamethylene diisocyanate, and even more preferably 1,5-pentamethylene diisocyanate.

[0021] The 1,5-pentamethylene diisocyanate is preferably plant-derived 1,5-pentamethylene diisocyanate. Plant-derived 1,5-pentamethylene diisocyanate can be obtained by enzymatic decarboxylation of lysine. A method for producing such plant-derived 1,5-pentamethylene diisocyanate is described in the specification of International Publication WO2012 / 121291.

[0022] When the aliphatic diisocyanate is 1,5-pentamethylene diisocyanate, the plant-based content of the polyurethane viscoelastic material can be improved.

[0023] The plant-based content of the plant-derived 1,5-pentamethylene diisocyanate is, for example, 10% or more and, for example, 80% or less.

[0024] The plant-based content can be measured according to the ASTM D6866 test method.

[0025] Examples of the derivatives of aliphatic polyisocyanates include polymers of the above-mentioned aliphatic polyisocyanates (for example, dimers, trimers (for example, isocyanurate derivatives, iminooxadiazinedione derivatives), pentamers, heptamers, etc.), allophanate derivatives (for example, allophanate derivatives produced by reacting the above-mentioned aliphatic polyisocyanates with monohydric alcohols or dihydric alcohols), and polyol derivatives (for example, polyol derivatives (alcohol adducts) produced by reacting the above-mentioned aliphatic polyisocyanates with trihydric alcohols (for example, trimethylolpropane)). and the like), biuret derivatives (for example, biuret derivatives produced by the reaction of the above-mentioned aliphatic polyisocyanates with water or amines, etc.), urea derivatives (for example, urea derivatives produced by the reaction of the above-mentioned aliphatic polyisocyanates with diamines, etc.), oxadiazinetrione derivatives (for example, oxadiazinetrione produced by the reaction of the above-mentioned aliphatic polyisocyanates with carbon dioxide gas, etc.), carbodiimide derivatives (for example, carbodiimide derivatives produced by the decarboxylation condensation reaction of the above-mentioned aliphatic polyisocyanates, etc.), uretdione derivatives, and uretonimine derivatives are included.

[0026] As the derivative, preferably, an isocyanurate derivative is used from the viewpoint of heat resistance and viscosity.

[0027] Isocyanurate derivatives of aliphatic polyisocyanates can be obtained by known methods. Specifically, first, a small amount of monool (e.g., isobutanol, 1,3-butanediol) is added to an aliphatic polyisocyanate and heated. Next, a known isocyanuration catalyst is added to the mixture to cause an isocyanuration reaction. The small amount of monool is added to promote the isocyanuration reaction, and does not remain as an allophanate group.

[0028] Furthermore, the isocyanurate derivative of the aliphatic polyisocyanate may have an allophanate group in addition to the isocyanurate group. In the following description, an isocyanurate derivative having an allophanate group in addition to the isocyanurate group may be referred to as an allophanate-isocyanurate derivative.

[0029] The allophanate-isocyanurate derivative of an aliphatic polyisocyanate can be obtained by a known method. Specifically, in the above-described method for producing an isocyanurate derivative of an aliphatic polyisocyanate, an effective amount of monool for generating allophanate groups is added to produce the allophanate-isocyanurate derivative.

[0030] In the allophanate-isocyanurate derivative of aliphatic polyisocyanate, the molar ratio of allophanate groups to isocyanurate groups (allophanate groups / isocyanurate groups) is, for example, 0.05 or more and, for example, 1 or less.

[0031] The molar ratio, which will be described in detail in the Examples below, can be calculated from the molar ratio of allophanate groups to isocyanurate groups obtained from an NMR chart measured by H-NMR for an allophanate-isocyanurate derivative of an aliphatic polyisocyanate.

[0032] More preferably, the derivative is an allophanate-isocyanurate derivative, from the viewpoint of further reducing the viscosity.

[0033] The derivatives of aliphatic polyisocyanates are preferably isocyanurate derivatives of 1,5-pentamethylene diisocyanate and isocyanurate derivatives of 1,6-hexamethylene diisocyanate, more preferably allophanate-isocyanurate derivatives of 1,5-pentamethylene diisocyanate and allophanate-isocyanurate derivatives of 1,6-hexamethylene diisocyanate, and even more preferably allophanate-isocyanurate derivatives of 1,5-pentamethylene diisocyanate.

[0034] The average number of functional groups of the derivative of aliphatic polyisocyanate is, for example, more than 2, preferably 2.5 or more, from the viewpoint of heat resistance, and is, for example, less than 4, preferably 3.5 or less, from the viewpoint of tensile strength.

[0035] The method for calculating the average number of functional groups will be described in detail in the Examples below.

[0036] The aliphatic polyisocyanate derivatives can be used alone or in combination of two or more kinds.

[0037] The polyisocyanate component may also contain an aliphatic polyisocyanate (an aliphatic polyisocyanate monomer) together with a derivative of the aliphatic polyisocyanate.

[0038] [Other polyisocyanates and / or their derivatives] The polyisocyanate component may further include other polyisocyanates and / or derivatives thereof.

[0039] Other polyisocyanates include, for example, aromatic diisocyanates and araliphatic diisocyanates.

[0040] Examples of aromatic diisocyanates include 4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate or a mixture thereof (MDI), 2,4- or 2,6-tolylene diisocyanate or a mixture thereof (TDI), o-tolidine diisocyanate, 1,5-naphthalene diisocyanate (NDI), m- or p-phenylene diisocyanate or a mixture thereof, 4,4'-diphenyl diisocyanate, and 4,4'-diphenyl ether diisocyanate.

[0041] Araliphatic diisocyanates include xylylene diisocyanate (1,2-, 1,3-, or 1,4-xylylene diisocyanate or mixtures thereof) (XDI), 1,3-, or 1,4-tetramethylxylylene diisocyanate or mixtures thereof (TMXDI), and ω,ω′-diisocyanato-1,4-diethylbenzene.

[0042] Examples of the derivatives of other polyisocyanates include the derivatives listed above as the derivatives of aliphatic polyisocyanates.

[0043] The mixing ratio of the other polyisocyanate or derivative thereof relative to 100 parts by mass of the polyisocyanate component is, for example, 5 parts by mass or less, preferably 1 part by mass or less, and for example, 0.1 parts by mass or more.

[0044] The other polyisocyanates and derivatives thereof can be used alone or in combination of two or more kinds.

[0045] The polyisocyanate component preferably contains a derivative of an aliphatic polyisocyanate and does not contain a monomer of an aliphatic polyisocyanate and other polyisocyanates and / or their derivatives. In other words, the polyisocyanate component preferably consists of a derivative of an aliphatic polyisocyanate.

[0046] The average number of functional groups of the polyisocyanate component is, for example, more than 2, preferably 2.5 or more, from the viewpoint of heat resistance, and is, for example, less than 4, preferably 3.5 or less, from the viewpoint of tensile strength.

[0047] <Polyol component> The polyol component includes a polycarbonate polyol and / or an aromatic ring-containing polyester polyol. The polycarbonate polyol and the aromatic ring-containing polyester polyol are macropolyols. The macropolyol is a high-molecular-weight polyol having a number-average molecular weight of 300 or more, preferably 400 or more, more preferably 500 or more, and 2000 or less, preferably 1500 or less, more preferably 1000 or less.

[0048] [Polycarbonate polyol] Polycarbonate polyols can be obtained by reacting dihydric alcohols with carbonate esters.

[0049] Examples of dihydric alcohols include 2-methyl-1,3-propanediol, 1,6-hexanediol, and isosorbide, and isosorbide is preferred.

[0050] Examples of carbonate esters include dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate.

[0051] A preferred example of the polycarbonate polyol is a polycarbonate polyol (isosorbide-containing polycarbonate polyol) obtained by reacting isosorbide with a carbonate ester.

[0052] The isosorbide-containing polycarbonate polyol is a plant-derived polycarbonate polyol derived from isosorbide (a plant-derived raw material).

[0053] The plant-based content of the isosorbide-containing polycarbonate polyol is, for example, 10% or more, preferably 20% or more, more preferably 30% or more, and for example, 80% or less.

[0054] The plant-based content can be measured according to the ASTM D6866 test method.

[0055] When the polycarbonate polyol is an isosorbide-containing polycarbonate polyol, the plant-based content of the polyurethane viscoelastic material can be improved, the turbidity of the polyurethane viscoelastic material can be suppressed, and the tensile strength of the polyurethane viscoelastic material can be improved.

[0056] Such polycarbonate polyols are preferably liquid at 23°C.

[0057] Commercially available polycarbonate polyols can also be used, such as ETERNACOLL UP-50 (liquid polycarbonate diol, manufactured by Ube Industries, Ltd.), Benebiol HS0840H (isosorbide-containing polycarbonate diol, manufactured by Mitsubishi Chemical Corporation), and Kuraray Polyol C-590 (polycarbonate diol, manufactured by Kuraray Co., Ltd.).

[0058] The polycarbonate polyols can be used alone or in combination of two or more kinds.

[0059] [Aromatic ring-containing polyester polyol] The aromatic ring-containing polyester polyol has an aromatic ring. Specifically, the aromatic ring-containing polyester polyol has an aromatic ring derived from an aromatic ring-containing polyhydric alcohol (described later) and / or an aromatic ring-containing polybasic acid (described later).

[0060] The aromatic ring-containing polyester polyol can be obtained, for example, by reacting a polyhydric alcohol with a polybasic acid under known conditions. In other words, the aromatic ring-containing polyester polyol is a condensation polymer obtained by condensation polymerization, and is distinguished from a cyclic polymer (polycaprolactone).

[0061] Examples of polyhydric alcohols include aromatic ring-containing polyhydric alcohols and non-aromatic ring-containing polyhydric alcohols.

[0062] Examples of aromatic ring-containing polyhydric alcohols include aromatic ring-containing diols, such as bisphenol A, bisphenol S, and bisphenol F.

[0063] Examples of non-aromatic ring polyhydric alcohols include dihydric alcohols and trihydric alcohols.

[0064] Examples of dihydric alcohols include C2-C20 alkanediols, alicyclic diols, C4-C10 ether diols, and heterocyclic diols. Examples of C2-C20 alkanediols include 1,2-ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, 3,3-dimethylolheptane, and 2,6-dimethyl-1-octene-3,8-diol. Examples of alicyclic diols include 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, and hydrogenated bisphenol A. Examples of C4-10 ether diols include diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of heterocyclic diols include isosorbide (1,4:3,6-dianhydroglucitol). Examples of trihydric alcohols include glycerin, trimethylolpropane, and triisopropanolamine.

[0065] The polyhydric alcohols can be used alone or in combination of two or more kinds.

[0066] Examples of polybasic acids include aromatic ring-containing polybasic acids and non-aromatic ring-containing polybasic acids.

[0067] Examples of aromatic ring-containing polybasic acids include aromatic dicarboxylic acids, such as phthalic acid (orthophthalic acid, isophthalic acid, and terephthalic acid), toluene dicarboxylic acid, and naphthalenedicarboxylic acid.

[0068] Examples of non-aromatic ring-containing polybasic acids include saturated aliphatic dicarboxylic acids (C11-13), unsaturated aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, other carboxylic acids, and acid anhydrides derived from these carboxylic acids. Examples of saturated aliphatic dicarboxylic acids (C11-13) include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, 3-methyl-3-ethylglutaric acid, azelaic acid, and sebacic acid. Examples of unsaturated aliphatic dicarboxylic acids include maleic acid, fumaric acid, and itaconic acid. Examples of alicyclic dicarboxylic acids include hexahydrophthalic acid. Examples of other carboxylic acids include dimer acid, hydrogenated dimer acid, and HET acid. Examples of acid anhydrides include oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, 2-alkyl (C12 to C18) succinic anhydride, tetrahydrophthalic anhydride, and trimellitic anhydride.

[0069] The polybasic acids can be used alone or in combination of two or more kinds.

[0070] As described above, the aromatic ring-containing polyester polyol can be obtained by reacting a polyhydric alcohol with a polybasic acid, in which at least one of the polyhydric alcohol and the polybasic acid is selected to have an aromatic ring.

[0071] Specifically, if the polyhydric alcohol is an aromatic ring-containing polyhydric alcohol, the polybasic acid includes an aromatic ring-containing polybasic acid and / or a non-aromatic ring-containing polybasic acid. Furthermore, if the polyhydric alcohol is a non-aromatic ring-containing polyhydric alcohol, the polybasic acid includes at least an aromatic ring-containing polybasic acid. On the other hand, if the polybasic acid is an aromatic ring-containing polybasic acid, the polyhydric alcohol includes an aromatic ring-containing polyhydric alcohol and / or a non-aromatic ring-containing polyhydric alcohol. Furthermore, if the polybasic acid is a non-aromatic ring-containing polybasic acid, the polyhydric alcohol includes at least an aromatic ring-containing polyhydric alcohol.

[0072] The aromatic ring-containing polyester polyols can be used alone or in combination of two or more kinds.

[0073] As described above, the polyol component includes a polycarbonate polyol and / or an aromatic ring-containing polyester polyol.

[0074] When the polyol component contains a polycarbonate polyol and an aromatic ring-containing polyester polyol, the blending ratio of the polycarbonate polyol is, for example, 40 parts by mass or more and, for example, 60 parts by mass or less, per 100 parts by mass of the total of the polycarbonate polyol and the aromatic ring-containing polyester polyol. The blending ratio of the aromatic ring-containing polyester polyol is, for example, 40 parts by mass or more and, for example, 60 parts by mass or less, per 100 parts by mass of the total of the polycarbonate polyol and the aromatic ring-containing polyester polyol.

[0075] [Other polyols] The polyol component may also include other polyols.

[0076] The other polyols include, for example, other macropolyols and low molecular weight polyols.

[0077] The other macropolyols are macropolyols other than the above-mentioned polycarbonate polyols and aromatic ring-containing polyester polyols. Specific examples of the other macropolyols include aromatic ring-free polyester polyols, polyether polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols.

[0078] Low molecular weight polyols are compounds having a number average molecular weight of less than 300, preferably less than 200.

[0079] Examples of the low molecular weight polyol include the above-mentioned non-aromatic ring-containing polyhydric alcohols.

[0080] The mixing ratio of the other polyols relative to 100 parts by mass of the polyol component is, for example, 5 parts by mass or less, preferably 1 part by mass or less, and for example, 0.1 parts by mass or more.

[0081] The other polyols can be used alone or in combination of two or more kinds.

[0082] From the viewpoint of improving the tensile strength of the polyurethane viscoelastic body, the polyol component preferably does not contain other polyols but contains a polycarbonate polyol and / or an aromatic ring-containing polyester polyol, and more preferably consists of a polycarbonate polyol and / or an aromatic ring-containing polyester polyol.

[0083] In particular, the polyol component preferably does not contain a low-molecular-weight polyol, but contains a polycarbonate polyol and / or an aromatic ring-containing polyester polyol. That is, the polyol component preferably does not contain a low-molecular-weight polyol, but contains only a macropolyol. In such a case, the polyol component does not contain a low-molecular-weight polyol as a chain extender, and therefore does not have hard segments derived from the low-molecular-weight polyol. This allows the elasticity of the polyurethane viscoelastic body to be reduced. Furthermore, since the polyol component contains only a macropolyol, the viscosity of the polyurethane viscoelastic body can be increased.

[0084] The polyol component more preferably contains at least a polycarbonate polyol, further preferably does not contain an aromatic ring-containing polyester polyol but contains a polycarbonate polyol, and particularly preferably consists of a polycarbonate polyol.

[0085] The hydroxyl value of the polyol component is 120 mgKOH / g or more, preferably 130 mgKOH / g or more, and 300 mgKOH / g or less, preferably 250 mgKOH / g or less, more preferably 200 mgKOH / g or less, and even more preferably 150 mgKOH / g or less.

[0086] When the hydroxyl value of the polyol component is equal to or greater than the above lower limit, the viscosity of the polyurethane viscoelastic body can be increased.

[0087] On the other hand, if the hydroxyl value of the polyol component is less than the above lower limit, the viscosity of the polyurethane viscoelastic body cannot be increased.

[0088] Furthermore, when the hydroxyl value of the polyol component is equal to or less than the above upper limit, the tensile properties (tensile strength, tensile elongation) of the polyurethane viscoelastic material can be improved.

[0089] On the other hand, if the hydroxyl value of the polyol component exceeds the upper limit, the tensile properties (tensile strength, tensile elongation) of the polyurethane viscoelastic material will decrease.

[0090] The hydroxyl value can be determined by the acetylation method or the phthalation method in accordance with Method A or Method B of JIS K1557-1.

[0091] The average number of functional groups in the polyol component is, for example, 2 or more and, for example, 3 or less. The number of functional groups in the polyol is preferably 2.

[0092] <Method of manufacturing polyurethane viscoelastic body> The polyurethane viscoelastic material contains a reaction product of a polyisocyanate component and a polyol component. In other words, the polyurethane viscoelastic material is obtained by reacting the polyisocyanate component with the polyol component. The reaction product is the main component of the polyurethane viscoelastic material. Specifically, the content of the reaction product relative to the polyurethane viscoelastic material is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more, and for example, 99.9% by mass or less.

[0093] Specifically, the polyurethane viscoelastic body is obtained by a one-shot method, for example, a known cast molding method, that is, the polyurethane viscoelastic body is a cast polyurethane.

[0094] More specifically, the method for producing a polyurethane viscoelastic body includes a first step of preparing a premix (resin premix) from a polyol component, a second step of blending a polyisocyanate component with the premix (resin premix) to prepare a mixture containing a polyisocyanate component and a polyol component, and a third step of molding the mixture to obtain a polyurethane viscoelastic body.

[0095] [1st step] In the first step, a premix (resin premix) is prepared from the polyol component. Specifically, additives and catalysts are added to the polyol component as needed, and the mixture is stirred as needed to prepare the premix (resin premix). In other words, the polyurethane viscoelastic material contains additives and catalysts as needed.

[0096] Examples of the additives include antifoaming agents, stabilizers, crosslinking agents, interconnecting agents, pigments (coloring pigments), dyes, curing accelerators, matting agents, adhesion promoters, internal mold release agents, and silane coupling agents.

[0097] The antifoaming agent is not particularly limited, and known antifoaming agents can be used, such as silicone surfactants.

[0098] Examples of the stabilizer include an antioxidant, an ultraviolet absorber, a heat stabilizer, and a light stabilizer, and preferably, an antioxidant, an ultraviolet absorber, and a light stabilizer.

[0099] Examples of the antioxidant include hindered phenol-based antioxidants, phosphorus-based antioxidants, and thiophene-based antioxidants, and preferably, hindered phenol-based antioxidants are used.

[0100] Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and cyanoacrylate-based ultraviolet absorbers, and preferably, benzotriazole-based ultraviolet absorbers are used.

[0101] Examples of the light stabilizer include hindered amine-based light stabilizers and blend-based light stabilizers.

[0102] The blending ratio of the additive relative to the polyurethane viscoelastic material is, for example, 0.099% by mass or more, and, for example, 15% by mass or less, preferably 8% by mass or less, more preferably 4% by mass or less, and even more preferably 0.9% by mass or less.

[0103] The additives can be used alone or in combination of two or more kinds.

[0104] Furthermore, as will be described in detail later, the polyurethane viscoelastic material preferably does not contain a plasticizer. Even without containing a plasticizer, the polyurethane viscoelastic material has high viscosity and therefore excellent impact resistance.

[0105] Examples of the catalyst include known urethanization catalysts, such as amines and organometallic compounds (for example, dibutyltin(IV) dilaurate), and preferably organometallic compounds.

[0106] The catalyst content relative to the polyurethane viscoelastic material is, for example, 0.001% by mass or more, and for example, 5% by mass or less, preferably 2% by mass or less, more preferably 1% by mass or less, and even more preferably 0.1% by mass or less.

[0107] The catalysts can be used alone or in combination of two or more kinds.

[0108] This prepares a premix (resin premix). The content of the polyol component in the premix (resin premix) is, for example, 80 mass % or more, preferably 90 mass % or more, and more preferably 95 mass % or more.

[0109] [Second process] In the second step, the polyisocyanate component is blended with the premix (resin premix), and if necessary, stirred to prepare a mixture containing the polyisocyanate component and the polyol component.

[0110] Specifically, the polyisocyanate component is blended into the premix (resin premix) so that the equivalent ratio (NCO / OH) of the isocyanate groups in the polyisocyanate component to the hydroxyl groups in the polyol component is, for example, 0.5 or more, preferably 0.8 or more, and for example, 1.5 or less, preferably 1.2 or less, more preferably less than 1, and even more preferably 0.95 or less.

[0111] If the equivalent ratio is less than 1, the polyisocyanate component is not blended in excess relative to the polyol component, and as a result, thermal crosslinking due to the excess polyisocyanate component is suppressed, allowing the viscosity of the polyurethane viscoelastic body to be increased.

[0112] This prepares a mixture containing the polyisocyanate component and the polyol component.

[0113] [3rd step] In the third step, the mixture is molded to obtain a polyurethane viscoelastic body.

[0114] For molding, a known heat molding method is selected.

[0115] The conditions for thermoforming are appropriately set depending on the purpose and application. In thermoforming, the forming temperature is, for example, 40° C. or higher, preferably 60° C. or higher, and, for example, 120° C. or lower, preferably 100° C. or lower. The forming time is, for example, 10 minutes or higher, preferably 30 minutes or higher, and, for example, 240 minutes or lower, preferably 120 minutes or lower.

[0116] This allows the mixture to be shaped and cured (the polyisocyanate component and the polyol component react to give a reaction product (cured product)), thereby giving a polyurethane viscoelastic body.

[0117] The plant-based content of the polyurethane viscoelastic body is, for example, 20% or more, preferably 40% or more, and, for example, 80% or less. When the plant-based content is equal to or more than the above lower limit, the environmental load can be reduced.

[0118] The method for calculating the plant-based content will be described in detail in the Examples below.

[0119] The polyurethane viscoelastic body preferably has transparency. Specifically, the total light transmittance (JIS K 7136-1) of the polyurethane viscoelastic body is, for example, 80% or more, preferably 90% or more, and, for example, 99% or less.

[0120] Furthermore, although this will be described in detail later, the D hardness reduction rate, which is an index of viscosity of the polyurethane viscoelastic body, is, for example, 0.1 or more, preferably 0.15 or more, and for example, 0.7 or less.

[0121] The method for measuring the D hardness reduction rate will be described in detail in the examples below.

[0122] The tensile strength (JIS K 7312) of the polyurethane viscoelastic body is, for example, 3.7 MPa or more, preferably 4 MPa or more, more preferably 8 MPa or more, even more preferably 12 MPa or more, particularly preferably 20 MPa or more, and is, for example, 40 MPa or less.

[0123] The tensile elongation (JIS K 7312) of the polyurethane viscoelastic body is, for example, 180% or more, preferably 200% or more, and, for example, 300% or less.

[0124] <Action and effect> The polyurethane viscoelastic material contains a reaction product of a polyisocyanate component containing an aliphatic polyisocyanate derivative and a polyol component containing a polycarbonate polyol and / or an aromatic ring-containing polyester polyol. The polyol component has a predetermined hydroxyl value, which improves tensile properties and increases viscosity.

[0125] In particular, since the polyol component contains a polycarbonate polyol and / or an aromatic ring-containing polyester polyol, the tensile properties can be improved and the viscosity can be increased from the viewpoint of the interaction between molecular chains.

[0126] Such a polyurethane viscoelastic body has a higher viscosity than polyurethane gel.

[0127] Specifically, polyurethane gel is an elastic material with low viscosity, so when a force is applied to such polyurethane gel to cause it to deform, and then the force is removed, the deformation returns to its original state immediately.

[0128] On the other hand, since the polyurethane viscoelastic material is a highly viscous elastic material, when a force is applied to the polyurethane viscoelastic material to cause deformation and then the force is removed, the deformation returns slowly, thereby improving impact resistance.

[0129] The viscosity of a polyurethane viscoelastic body can be estimated by the rate of decrease in hardness, such as D hardness, over time (D hardness decrease rate). If the D hardness decrease rate is within the above range, it can be determined that the viscosity of the polyurethane viscoelastic body is high.

[0130] As described above, the polyurethane viscoelastic body is a highly viscous elastic body (viscoelastic body). As described above, the viscosity of the polyurethane viscoelastic body can be estimated by the D-hardness reduction rate. The elasticity of the polyurethane viscoelastic body can be estimated by the tensile strength and tensile elongation. In other words, a polyurethane viscoelastic body is one whose D-hardness reduction rate satisfies the above-mentioned ranges and whose tensile strength and tensile elongation also satisfy the above-mentioned ranges.

[0131] Furthermore, when such a polyurethane viscoelastic body is deformed by application of force and then the force is removed, the deformation slowly returns to its original shape and eventually returns to its original shape.

[0132] Furthermore, the polyurethane viscoelastic material preferably does not contain a plasticizer. If the polyurethane viscoelastic material contains a plasticizer, the plasticizer may bleed out, contaminating the surface of the polyurethane viscoelastic material. On the other hand, even if the polyurethane viscoelastic material does not contain a plasticizer, it has high viscosity and therefore excellent impact resistance. Furthermore, because the polyurethane viscoelastic material does not contain a plasticizer, the above-mentioned contamination can be suppressed.

[0133] Furthermore, polyurethane viscoelastic materials have excellent tensile properties and high viscosity, and therefore can be used in a wide range of industrial applications, and are particularly suitable for use as materials for components that require impact resistance.

[0134] <Modification> In the modified example, the same components and steps as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. Furthermore, the modified example can achieve the same effects as those in the first embodiment unless otherwise specified. Furthermore, the first embodiment and the modified example can be combined as appropriate.

[0135] In the above explanation, in the first step, additives and catalysts are blended with the polyol component to prepare a premix (resin premix), and then in the second step, the polyisocyanate component is blended with the premix (resin premix) to prepare a mixture; however, additives and catalysts can also be blended simultaneously with or after blending the polyol component and polyisocyanate component. [Example]

[0136] 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."

[0137] 1.Ingredient details The trade names and abbreviations of the components used in each Production Example, each Example, and each Comparative Example are described in detail below. HS0840H: Isosorbide-containing polycarbonate diol, average hydroxyl value 140 mg KOH / g, average functionality 2, plant-based content 37% according to ASTM D6866, product name "Benebiol HS0840H", manufactured by Mitsubishi Chemical Corporation UP-50: Liquid polycarbonate diol, average hydroxyl value 222 mg KOH / g, average functionality 2, product name "ETERNACOL UP-50", manufactured by Ube Industries, Ltd. T5651: Liquid polycarbonate diol, average hydroxyl value 110 mg KOH / g, average functionality 2, product name "Duranol T5651", manufactured by Asahi Kasei Corporation C-590: Liquid polycarbonate diol, average hydroxyl value 224 mg KOH / g, average functionality 2, product name "Kuraray Polyol C-590", manufactured by Kuraray Co., Ltd. Polyol A: Aromatic ring-containing polyester polyol, average hydroxyl value 222 mg KOH / g, average functionality 2 DPG: Dipropylene glycol, average hydroxyl value 836 mg KOH / g, average functionality 2, manufactured by ADEKA PTG650: Polytetramethylene ether polyol, average hydroxyl value 172 mg KOH / g, average functionality 2, trade name "PTG-650", manufactured by Hodogaya Chemical Co., Ltd. D-400: Propylene oxide polymer, hydroxyl value: 280 mg KOH / g, average functionality: 2, product name "Actocol D-400", manufactured by Mitsui Chemicals SKC U-550: Polyester polyol (polyester polyol not containing aromatic rings), hydroxyl value 202 mg KOH / g, average functionality 2, product name "Takelac U-550", manufactured by Mitsui Chemicals SKC Placcel 205U: Polycaprolactone diol (aromatic ring-free polyester polyol, cyclic polymer), hydroxyl value 212 mg KOH / g, average functionality 2, trade name "Placcel 205U", manufactured by Daicel Corporation Antifoaming agent: Silicone surfactant, product name "BYK-088", manufactured by BYK Japan Catalyst: dibutyltin(IV) dilaurate, manufactured by Tokyo Chemical Industry Co., Ltd. Antioxidant: Hindered phenol compound, product name "Irganox 245", manufactured by BASF Japan Ltd. UV absorber: Benzotriazole compound, trade name "Tinuvin 234", manufactured by BASF Japan Ltd. Light stabilizer: bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, trade name "ADEKA STAB LA-72", manufactured by ADEKA

[0138] 2. Synthesis of aliphatic polyisocyanate derivatives Synthesis Example 1 (Allophanate-Isocyanurate Derivative of 1,5-Pentamethylene Diisocyanate (1,5-PDI)) In a reactor equipped with a thermometer, a stirrer, a nitrogen inlet, and a condenser, 500 parts by mass of 1,5-pentamethylene diisocyanate (PDI, manufactured by Mitsui Chemicals, Inc., trade name: Stabio PDI), 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) were mixed under a nitrogen atmosphere. 6.5 parts by mass of isobutanol (an effective amount for generating allophanate groups) was then added to the mixture, and nitrogen was introduced into the liquid phase for 1 hour. The mixture was then heated to 80°C and reacted for 3 hours (partial reaction), after which it was cooled to 60°C. 0.2 parts by mass of trimethyl-N-2-hydroxypropylammonium 2-ethylhexanoate (an isocyanurate catalyst) was added and reacted for 1.5 hours. Next, 0.01 parts by mass of o-toluenesulfonamide was added to 100 parts by mass of PDI. The reaction mixture was then passed through a thin-film distillation apparatus (temperature: 150°C, vacuum: 93.3 Pa) and distilled until the amount of residual PDI monomer was 1.0% or less, yielding an aliphatic polyisocyanate derivative (an isocyanurate derivative of 1,5-pentamethylene diisocyanate). The resulting aliphatic polyisocyanate derivative had an isocyanate group content of 24.0% and an average number of isocyanate functional groups of 2.8.

[0139] Synthesis Example 2 (Allophanate-Isocyanurate Derivative of 1,6-Hexamethylene Diisocyanate (1,6-HDI)) In a reactor equipped with a thermometer, stirrer, nitrogen inlet, and condenser, 500 parts by weight of 1,6-hexamethylene diisocyanate (HDI, manufactured by Mitsui Chemicals, Inc., trade name: Takenate 700), 0.25 parts by weight of 2,6-di(tert-butyl)-4-methylphenol (also known as dibutylhydroxytoluene, BHT, a hindered phenol-based antioxidant), and 0.25 parts by weight of tetraphenyl dipropylene glycol diphosphite (an organic phosphite ester, a cocatalyst) were mixed under a nitrogen atmosphere. To this mixture, 10.7 parts by weight of 1,3-butanediol (an effective amount for generating allophanate groups) was added, and nitrogen was introduced into the liquid phase for 1 hour. The mixture was then heated to 80°C and reacted for 3 hours, after which the temperature was lowered to 60°C. Next, 0.2 parts by mass of trimethyl-N-2-hydroxypropylammonium 2-ethylhexanoate was added as an isocyanuration catalyst, and the mixture was allowed to react for 1.5 hours. Then, 0.01 parts by mass of o-toluenesulfonamide was added per 100 parts by mass of HDI. The reaction mixture was then passed through a thin-film distillation apparatus (temperature: 150°C, vacuum: 93.3 Pa) and distilled until the residual HDI monomer content was 1.0% or less, yielding an aliphatic polyisocyanate derivative (allophanate-isocyanurate derivative of 1,6-hexamethylene diisocyanate). The resulting aliphatic polyisocyanate derivative had an isocyanate group content of 20.7% and an average isocyanate functionality of 3.4.

[0140] 3. Production of polyurethane viscoelastic body Example 1 [1st step] 100 parts by mass of a polyol polyol component heated to 80°C was mixed with the following components (0.2 parts by mass of antifoaming agent, 0.01 parts by mass of catalyst, 0.1 parts by mass of antioxidant, 0.1 parts by mass of UV absorber, and 0.1 parts by mass of light stabilizer) according to the formulation below, and the mixture was stirred with a three-one motor to prepare a resin premix.

[0141] [Second process] The polyisocyanate component was blended with 100 parts by mass of the resin premix so that the equivalent ratio (NCO / OH) of the isocyanate groups in the polyisocyanate component to the hydroxyl groups in the polyol component was 0.9, and then the mixture was stirred for approximately 5 minutes using a vacuum planetary centrifugal mixer to prepare a mixture.

[0142] [3rd step] The mixture was poured into a mold, taking care to avoid the formation of bubbles, and cured in an oven at 80°C for 1 hour. The molded product was then demolded to obtain a polyurethane viscoelastic body. Two molds were used: a SUS mold (first mold) with inner dimensions of 300 mm x 100 mm x 2 mm, and a SUS mold (second mold) with a diameter of 275 mm x 125 mm, to obtain two polyurethane viscoelastic bodies.

[0143] Example 2 to Example 4 , and Comparative Example 1 to Comparative Example 7 Two polyurethane viscoelastic bodies were obtained according to the same procedure as in Example 1. However, the formulations of the polyisocyanate component and the polyol component were changed according to Table 1. The formulations of the polyisocyanate component and the polyol component in Table 1 are in parts by mass.

[0144] 4. Evaluation <Average number of isocyanate functional groups> The average number of isocyanate functional groups of the aliphatic polyisocyanate derivative in each synthesis example was calculated from the isocyanate group concentration A, solid content concentration B, and number average molecular weight C measured by gel permeation chromatography using the following apparatus and conditions, according to the following formula (1): Average number of isocyanate functional groups = A / B × C / 42.02 (1) (In the formula, A represents the isocyanate group concentration of the aliphatic polyisocyanate derivative, B represents the solid content concentration, and C represents the number average molecular weight.)

[0145] [Apparatus and conditions] Device: HLC-8220GPC (Tosoh) Columns: TSKgel G1000HXL, TSKgel G2000HXL, and TSKgel G3000HXL (manufactured by Tosoh) connected in series. Detector: differential refractometer Injection volume: 100μL Eluent: tetrahydrofuran Flow rate: 0.8mL / min Temperature: 40℃ Calibration curve: Standard polyethylene oxide in the range of 106 to 22450 (manufactured by Tosoh, product name: TSK Standard Polyethylene Oxide)

[0146] <Measurement of the molar ratio of allophanate groups to isocyanurate groups (allophanate groups / isocyanurate groups)> The aliphatic polyisocyanate derivatives of each synthesis example were subjected to 1H-NMR measurement (400 MHz, solvent: D6-DMSO (solute: 5% by mass), standard substance: tetramethylsilane).

[0147] The peaks at 8.3 to 8.7 ppm were assigned to the proton peaks of the allophanate groups (NH groups in the allophanate groups), and the peak at 3.8 ppm was assigned to the proton peak of the isocyanurate groups (methylene groups (CH groups) directly bonded to the isocyanurate groups). Next, the molar ratio of allophanate groups to isocyanurate groups (allophanate groups / isocyanurate groups) was calculated from the peak area ratio (integral ratio) using the following formula (2):

[0148] Molar ratio = integral value of the peak assigned to the protons of the allophanate group / (integral value of the peak assigned to the protons of the isocyanurate group / 6) (2)

[0149] The molar ratio of the aliphatic polyisocyanate derivative in Synthesis Example 1 was 0.5. The molar ratio of the aliphatic polyisocyanate derivative in Synthesis Example 2 was 0.4.

[0150] <Plant level> The biomass degree was calculated based on the following formula (3). Sum of (biomass fraction × carbon content × usage amount) of each biomass raw material / Sum of (carbon content × usage amount) of all raw materials (3)

[0151] In the above formula (3), the biomass fraction of each raw material was determined based on the American Society for Testing and Materials (ASTM D6866).

[0152] Regarding the carbon content, for monomers and oligomers with a clear structure, the carbon content was calculated from the calculated values of their molecular formulas, and for those with an unclear structure, the carbon content was calculated by elemental analysis.

[0153] Also, it was assumed that the organic solvent was not contained in all the raw materials. The results are shown in Table 1.

[0154] <D hardness> Regarding the polyurethane viscoelastic body of each example and each comparative example (the polyurethane viscoelastic body obtained using the second mold), the D hardness was measured in accordance with JIS K6253-3.

[0155] Specifically, the D hardness at the moment when the hardness tester was pressed against the polyurethane viscoelastic body (D hardness (moment)) and the D hardness 10 seconds after the hardness tester was pressed against the polyurethane viscoelastic body (D hardness (after 10 seconds)) were measured. The results are shown in Table 1.

[0156] Also, based on the following formula (4), the D hardness reduction rate was calculated. The results are shown in Table 1. The larger the D hardness reduction rate, the higher the viscosity, and it can be seen that after applying a force and causing deformation, the deformation slowly returns when the force is removed. {D hardness (moment) - D hardness (after 10 seconds)} / D hardness (moment) = D hardness reduction rate (4)

[0157] <Tensile properties> The tensile strength and tensile elongation of the polyurethane viscoelastic bodies (polyurethane viscoelastic bodies obtained using the first mold) of each Example and Comparative Example were measured in accordance with JIS K 7312. Specifically, measurements were made on a 2 mm thick No. 3 dumbbell specimen at a pulling speed of 500 mm / min. The results are shown in Table 1.

[0158] <Haze and total light transmittance> The polyurethane viscoelastic bodies (polyurethane viscoelastic bodies obtained using the first mold) of each Example and Comparative Example were measured for haze and total light transmittance according to JIS K 7136-1. Specifically, a Haze Meter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd. was used, and the light source was D65 / A. The results are shown in Table 1.

[0159] [Table 1]

Claims

1. a polyisocyanate component including a derivative of an aliphatic polyisocyanate; a reaction product with a polyol component including a polycarbonate polyol and / or an aromatic ring-containing polyester polyol; the hydroxyl value of the polyol component is 120 mgKOH / g or more and 300 mgKOH / g or less; The polyurethane viscoelastic material, wherein the aliphatic polyisocyanate in the derivative of the aliphatic polyisocyanate includes 1,5-pentamethylene diisocyanate.

2. 2. The polyurethane viscoelastic material according to claim 1, wherein the average number of functional groups of the derivative of the aliphatic polyisocyanate is more than 2 and less than 4.

3. 3. The polyurethane viscoelastic material according to claim 1, wherein the derivative of the aliphatic polyisocyanate is an allophanate-isocyanurate derivative.

4. The polyurethane viscoelastic material according to any one of claims 1 to 3, having a plant-based content of 40% or more.

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