Cast Polyurethane Elastomer

Abstract

To provide a polyurethane elastomer capable of improving compression set, acid resistance, alkali resistance, and hot water resistance.SOLUTION: A polyurethane elastomer includes: a reaction product of a polyisocyanate constituent including m-xylylene diisocyanate, a macropolyol constituent including polycarbonate polyol, and a chain-elongating constituent including 3,3'-dichloro-4,4'-diphenyl methanediamine, where the number average molecular weight of the macropolyol constituent is more than 500 and less than 2,000.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Polyurethane elastomers have a soft segment formed by the reaction of polyisocyanate with a macropolyol, and a hard segment formed by the reaction of polyisocyanate with a chain extender. Polyurethane elastomers are rubber elastic bodies and are widely used in various industrial fields such as industrial rolls that require abrasion resistance.

[0003] More specifically, a polyurethane elastomer is known that can be obtained by the following method: First, p-xylylene diisocyanate is reacted with polytetramethylene ether glycol to obtain a prepolymer, and then the prepolymer is reacted with 3,3'-dichloro-4,4-diaminodiphenylmethane (MOCA) to obtain a polyurethane elastomer (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2-166113 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the polyurethane elastomer described in Patent Document 1 has problems such as insufficient compression set, acid resistance, alkali resistance, and hot water resistance.

[0006] The present invention provides a polyurethane elastomer that can improve compression set, acid resistance, alkali resistance, and hot water resistance. [Means for solving the problem]

[0007] The present invention [1] comprises a polyisocyanate component containing m-xylylene diisocyanate, The polyurethane elastomer comprises a reaction product of a macropolyol component including a polycarbonate polyol and a chain extender component including 3,3'-dichloro-4,4'-diphenylmethanediamine, the number average molecular weight of the macropolyol component being greater than 500 and less than 2,000.

[0008] The present invention [2] includes the polyurethane elastomer described in [1] above, which includes a secondary reaction product between an isocyanate-terminated prepolymer component containing a primary reaction product of the polyisocyanate component and the macropolyol component, and the chain extension component.

[0009] The present invention [3] includes the polyurethane elastomer described in [2] above, in which the equivalent ratio (NCO / OH) of the isocyanate groups in the polyisocyanate component to the hydroxyl groups in the macropolyol component is greater than 1.5 and less than 3.0. Effect of the Invention

[0010] The polyurethane elastomer of the present invention comprises a polyisocyanate component including m-xylylene diisocyanate, a macropolyol component including a polycarbonate polyol, and a chain extender component including 3,3'-dichloro-4,4'-diphenylmethanediamine (MOCA). The number average molecular weight of the macropolyol component is more than 500 and less than 2000. Therefore, the polyurethane elastomer of the present invention can achieve improvements in compression set, acid resistance, alkali resistance, and hot water resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The polyurethane elastomer is a TPU (thermoplastic polyurethane resin) or a TSU (thermosetting polyurethane resin). Preferably, the polyurethane elastomer is a TSU (thermosetting polyurethane resin). The polyurethane elastomer comprises a reaction product of a polyisocyanate component, a macropolyol component, and a chain extending component.

[0012] The polyisocyanate component contains m-xylylene diisocyanate as an essential component. The ratio of m-xylylene diisocyanate in the polyisocyanate component is, for example, 50% by mass or more, preferably 90% by mass or more, and more preferably 95% by mass or more. More preferably, the polyisocyanate component consists of m-xylylene diisocyanate.

[0013] Furthermore, the polyisocyanate component may contain, as an optional component, a polyisocyanate other than m-xylylene diisocyanate (hereinafter referred to as other polyisocyanate).

[0014] Other polyisocyanates include polyisocyanate monomers (excluding m-xylylene diisocyanate) and modified polyisocyanates. Examples of polyisocyanate monomers include aromatic polyisocyanates, aliphatic polyisocyanates, and araliphatic polyisocyanates (excluding m-xylylene diisocyanate). Examples of aromatic polyisocyanates include diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), toluidine diisocyanate (TODI), paraphenylene diisocyanate, and naphthalene diisocyanate (NDI). Examples of aliphatic polyisocyanates include linear aliphatic polyisocyanates and alicyclic polyisocyanates. Examples of linear aliphatic polyisocyanates include pentamethylene diisocyanate (PDI) and hexamethylene diisocyanate (HDI). Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), methylene bis(cyclohexyl isocyanate) (H 12 MDI), and bis(isocyanatomethyl)cyclohexane (H 6 Examples of aromatic aliphatic polyisocyanates include p-xylylene diisocyanate (p-XDI) and tetramethylxylylene diisocyanate (TMXDI). These can be used alone or in combination of two or more kinds.

[0015] The polyisocyanate modified product includes a modified product obtained by modifying m-xylylene diisocyanate or a polyisocyanate monomer by a known method. The polyisocyanate modified product includes, for example, a uretdione modified product, an isocyanurate modified product, an allophanate modified product, a polyol modified product, a biuret modified product, a urea modified product, an oxadiazinetrione modified product, and a carbodiimide modified product. These may be used alone or in combination of two or more types.

[0016] The content of other polyisocyanates in the polyisocyanate component is, for example, 50% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably, the polyisocyanate component does not contain other polyisocyanates.

[0017] The macropolyol component is an organic compound having two or more hydroxyl groups in the molecule and a relatively high molecular weight (number average molecular weight (Mn) is, for example, 500 or more, more preferably 800 or more, and for example, 3000 or less, more preferably 2000 or less). The macropolyol component contains polycarbonate polyol as an essential component. The proportion of polycarbonate polyol in the macropolyol component is, for example, 50% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more. More preferably, the macropolyol component is composed of polycarbonate polyol.

[0018] Examples of polycarbonate polyols include ring-opening polymers of ethylene carbonate using a low molecular weight polyol (preferably a dihydric alcohol) as an initiator, such as copolymers of a dihydric alcohol, such as 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, or 1,6-hexanediol, with a ring-opening polymer. Polycarbonate polyols are classified into crystalline polycarbonate polyols (crystalline means a wax-like solid at 25°C) and amorphous polycarbonate polyols (amorphous means a highly viscous liquid at 25°C). Preferably, crystalline polycarbonate polyols are used. These can be used alone or in combination of two or more types.

[0019] The number average molecular weight (Mn) of the polycarbonate polyol is, for example, 500 or more, preferably 800 or more, more preferably 1000 or more. The number average molecular weight of the polycarbonate polyol is, for example, 5000 or less, preferably 2000 or less, more preferably 1800 or less, and even more preferably 1500 or less. Within the above range, a polyurethane elastomer can be obtained that can improve compression set, acid resistance, alkali resistance, and hot water resistance. The number average molecular weight can be measured as a polystyrene-equivalent molecular weight by gel permeation chromatography (hereinafter the same).

[0020] The average number of hydroxyl groups of the polycarbonate polyol is, for example, 2.0 or more. The average number of hydroxyl groups of the polycarbonate polyol is, for example, 3.0 or less. The average number of hydroxyl groups of the polycarbonate polyol is preferably 2.0.

[0021] The average number of hydroxyl groups of the polycarbonate polyol can be calculated by a known method from the type of initiator, or the number average molecular weight (Mn) and the average hydroxyl equivalent.

[0022] The macropolyol component may contain a macropolyol other than the polycarbonate polyol (hereinafter, referred to as other macropolyol) as an optional component.

[0023] Other macropolyols include, for example, polyether polyols, polyester polyols, vegetable oil polyols, polyolefin polyols, and acrylic polyols.

[0024] The other macropolyols can be used alone or in combination of two or more kinds.

[0025] The content of other macro-polyols in the macro-polyol component is, for example, 50% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less. More preferably, the macro-polyol component does not contain other macro-polyols.

[0026] The number average molecular weight (Mn) of the macropolyol component is, for example, 500 or more, preferably 800 or more, and more preferably 1000 or more. The number average molecular weight of the macropolyol component is, for example, 5000 or less, preferably 2000 or less, more preferably 1800 or less, and even more preferably 1500 or less. If the number average molecular weight (Mn) of the macropolyol component is within the above range, a polyurethane elastomer can be obtained that can improve compression set, acid resistance, alkali resistance, and hot water resistance.

[0027] The number average molecular weight (Mn) can be calculated from the hydroxyl equivalent and the average number of hydroxyl groups by a known method. The number average molecular weight can also be measured as a polystyrene-equivalent molecular weight by gel permeation chromatography (hereinafter the same).

[0028] The average number of hydroxyl groups of the macro-polyol component is, for example, 2.0 or more. The average number of hydroxyl groups of the macro-polyol component is, for example, 3.0 or less. The average number of hydroxyl groups of the macro-polyol component is preferably 2.0. The average number of hydroxyl groups can be calculated by a known method from the type of initiator, or the number average molecular weight (Mn) and the average hydroxyl equivalent.

[0029] The chain extension component contains 3,3'-dichloro-4,4'-diphenylmethanediamine (MOCA) as an essential component. The proportion of 3,3'-dichloro-4,4'-diphenylmethanediamine (MOCA) in the chain extension component is, for example, 50% by mass or more, preferably 90% by mass or more, and more preferably 95% by mass or more. More preferably, the chain extension component consists of 3,3'-dichloro-4,4'-diphenylmethanediamine (MOCA).

[0030] The chain extending component may contain, as an optional component, a chain extender other than 3,3'-dichloro-4,4'-diphenylmethanediamine (MOCA) (hereinafter, referred to as other chain extender). In order to improve hardness, the chain extending component preferably does not contain a low molecular weight polyol as an optional component.

[0031] Other chain extenders include, for example, aromatic polyamines (excluding 3,3'-dichloro-4,4'-diphenylmethanediamine (MOCA)).

[0032] Examples of aromatic polyamines include aromatic diamines (excluding MOCA). Examples of aromatic diamines include 2,4-diethyltoluenediamine, 2,6-diethyltoluenediamine, dimethylthiotoluenediamine, 4,4'-diphenylmethanediamine, 4,4'-methylenebis(n-sec-butylaniline), 4,4'-methylenebis(2,6-diethylaniline), 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, and tetrachloro-4,4'-diaminodiphenylmethane. Examples of aromatic polyamines include commercially available products. Examples of commercially available products include Ethacure 100 (a mixture of 2,4-diethyltoluenediamine and 2,6-diethyltoluenediamine, manufactured by Albemarle), Ethacure 300 (dimethylthiotoluenediamine, manufactured by Albemarle), Ethacure 420 (4,4'-methylenebis(n-sec-butylaniline), manufactured by Albemarle), LonzaCure M-DEA (4,4'-methylenebis(2,6-diethylaniline), manufactured by Lonza), Curehard MED-J (4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane), and TCDAM (tetrachloro-4,4'-diaminodiphenylmethane, manufactured by Ihara Chemical Co.). These can be used alone or in combination of two or more types.

[0033] The content of the other chain extender in the chain extender component is, for example, 50 mass % or less, preferably 10 mass % or less, more preferably 5 mass % or less, and further preferably, the chain extender component does not contain any other chain extender.

[0034] The content of the polyisocyanate component is, for example, 20% by mass or more, preferably 25% by mass or more, based on the total amount of the polyisocyanate component and the macropolyol component. The content of the polyisocyanate component is, for example, 50% by mass or less, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 32% by mass or less. If the content of the polyisocyanate component is within the above range, the polyurethane elastomer of the present invention can improve the compression set, acid resistance, alkali resistance, and hot water resistance.

[0035] The content of the macro-polyol component is, for example, 60% by mass or more, preferably 65% ​​by mass or more, more preferably 70% by mass or more, based on the total amount of the polyisocyanate component and the macro-polyol component. The content of the macro-polyol component is, for example, 85% by mass or less, preferably 80% by mass or less, more preferably 75% by mass or less. If the content of the macro-polyol component is within the above range, the polyurethane elastomer of the present invention can improve the compression set, acid resistance, alkali resistance, and hot water resistance.

[0036] The content of the chain extension component is, for example, 10 parts by mass or more, preferably 13 parts by mass or more, and more preferably 16 parts by mass or more, based on 100 parts by mass of the total amount of the polyisocyanate component and the macropolyol component. The content of the chain extension component is, for example, 30 parts by mass or less, preferably 23 parts by mass or less, and more preferably 20 parts by mass or less. If the content of the chain extension component is within the above range, the polyurethane elastomer of the present invention can achieve improved compression set, acid resistance, alkali resistance, and hot water resistance.

[0037] The content of the polyisocyanate component relative to the total amount of the polyurethane elastomer (the total amount of the polyisocyanate component, the macropolyol component, and the chain extension component, the same applies below) is, for example, 15% by mass or more, preferably 20% by mass or more, and more preferably 22% by mass or more. The content of the polyisocyanate component is, for example, 40% by mass or less, preferably 30% by mass or less, and more preferably 25% by mass or less. If the content of the polyisocyanate component is within the above range, the polyurethane elastomer of the present invention can achieve improved compression set, acid resistance, alkali resistance, and hot water resistance.

[0038] The content ratio of the macro-polyol component relative to the total amount of the polyurethane elastomer is, for example, 50% by mass or more, preferably 55% by mass or more, more preferably 60% by mass or more. The content ratio of the macro-polyol component is, for example, 70% by mass or less, preferably 65% ​​by mass or less, more preferably 62% by mass or less. If the content ratio of the macro-polyol component is within the above range, the polyurethane elastomer of the present invention can improve the compression set, acid resistance, alkali resistance, and hot water resistance.

[0039] The content of the chain extension component relative to the total amount of the polyurethane elastomer is, for example, 10% by mass or more, preferably 12% by mass or more, and more preferably 14% by mass or more. The content of the chain extension component is, for example, 30% by mass or less, preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 15% by mass or less. When the content of the chain extension component is within the above range, the polyurethane elastomer of the present invention can achieve improved compression set, acid resistance, alkali resistance, and hot water resistance.

[0040] Examples of methods for producing polyurethane elastomers include known methods such as a one-shot method and a prepolymer method, and preferably the prepolymer method. In the one-shot method, for example, a polyisocyanate component, a macropolyol component, and a chain extension component are reacted at once. In the prepolymer method, for example, a polyisocyanate component and a macropolyol component are reacted first to synthesize an isocyanate-terminated prepolymer component having an isocyanate group at the molecular end. Then, the obtained isocyanate-terminated prepolymer component is reacted with a chain extension component.

[0041] That is, the polyurethane elastomer preferably contains a secondary reaction product between an isocyanate-terminated prepolymer component containing a primary reaction product and a chain extension component. The primary reaction product is a reaction product between a polyisocyanate component and a macropolyol component. The secondary reaction product is a reaction product between an isocyanate-terminated prepolymer component and a chain extension component.

[0042] The isocyanate-terminated prepolymer component contains a primary reaction product of a polyisocyanate component and a macropolyol component.

[0043] In the prepolymer method, first, a polyisocyanate component and a macropolyol component are reacted to obtain an isocyanate-terminated prepolymer component containing a primary reaction product.

[0044] The isocyanate group-terminated prepolymer component can be obtained, for example, by reacting a polyisocyanate component with a macropolyol component in a predetermined ratio (prepolymer process).

[0045] The blending ratio of the polyisocyanate component and the macro polyol component is adjusted so that the isocyanate group of the polyisocyanate component is in excess relative to the hydroxyl group of the macro polyol component. More specifically, the equivalent ratio (NCO / OH) of the isocyanate group (NCO) in the polyisocyanate component to the hydroxyl group (OH) in the macro polyol component is, for example, more than 1.5, preferably 1.7 or more, more preferably 1.8 or more. In addition, the equivalent ratio (isocyanate group / hydroxyl group) of the isocyanate group in the polyisocyanate component to the hydroxyl group in the macro polyol component is, for example, less than 3.0, preferably 2.5 or less, more preferably 2.2 or less. If the equivalent ratio (NCO / OH) is within the above range, a polyurethane elastomer that can improve compression set, acid resistance, alkali resistance, and hot water resistance can be obtained.

[0046] Examples of the polymerization method include bulk polymerization and solution polymerization. In bulk polymerization, for example, a polyisocyanate component and a macropolyol component are reacted under a nitrogen gas flow. The reaction temperature is, for example, 50° C. or higher. The reaction temperature is, for example, 250° C. or lower, preferably 200° C. or lower. The reaction time is, for example, 0.5 hours or more, preferably 1 hour or more. The reaction time is, for example, 15 hours or less. In solution polymerization, a polyisocyanate component and a macropolyol component are reacted in the presence of a known organic solvent. The reaction temperature is, for example, 50° C. or higher. The reaction temperature is, for example, 120° C. or lower, preferably 100° C. or lower. The reaction time is, for example, 0.5 hours or more, preferably 1 hour or more. The reaction time is, for example, 15 hours or less.

[0047] If necessary, a known urethanization catalyst can be added. Examples of the urethanization catalyst include amines and organometallic compounds. The ratio of the urethanization catalyst to be added is appropriately set depending on the purpose and application.

[0048] This results in the production of an isocyanate-terminated prepolymer component (prepolymer reaction liquid) containing the primary reaction product. The isocyanate-terminated prepolymer component obtained by the above reaction can contain unreacted polyisocyanate (polyisocyanate component) in addition to the isocyanate-terminated prepolymer (primary reaction product). The unreacted polyisocyanate is removed from the reaction mixture by a known removal method, as necessary. Examples of the removal method include a distillation method and an extraction method.

[0049] From the viewpoint of improving the cohesiveness of the hard segment, the isocyanate-terminated prepolymer preferably contains a primary reaction product and an unreacted polyisocyanate.

[0050] The isocyanate group concentration of the isocyanate group-terminated prepolymer component is, for example, 4.0% by mass or more, preferably 5.0% by mass or more, and more preferably 5.5% by mass or more. The isocyanate group concentration of the isocyanate group-terminated prepolymer is 9.0% by mass or less, preferably 8.0% by mass or less, more preferably 7.0% by mass or less, and even more preferably 6.5% by mass or less. The isocyanate group concentration (isocyanate group content) can be determined by known methods such as titration with di-n-butylamine or FT-IR analysis.

[0051] The polyurethane elastomer is obtained by reacting the above-mentioned isocyanate group-terminated prepolymer component with a chain extension component (chain extension step).

[0052] The blending ratio of the isocyanate-terminated prepolymer component and the chain extension component is adjusted as the equivalent ratio of the amino groups of the chain extension component to the isocyanate groups of the isocyanate-terminated prepolymer component.

[0053] More specifically, for example, the equivalent ratio of the amino group of the chain extension component to the isocyanate group in the isocyanate group-terminated prepolymer component (amino group / isocyanate group) is, for example, 0.80 or more, preferably 0.85 or more, and for example, 1.1 or less, preferably less than 1.0, more preferably 0.95 or less. From the viewpoint of obtaining a desired hardness, it is preferably less than 1.0.

[0054] In addition, for example, bulk polymerization and / or solution polymerization is adopted in the reaction between the isocyanate group-terminated prepolymer component and the chain extension component. The reaction temperature is, for example, room temperature (25°C) or higher, preferably 50°C or higher. The reaction temperature is, for example, 200°C or lower, preferably 150°C or lower. The reaction time is, for example, 5 minutes or longer, preferably 1 hour or longer. The reaction time is, for example, 72 hours or shorter, preferably 48 hours or shorter. When mixing the isocyanate group-terminated prepolymer component and the chain extension component, a urethane catalyst can be added at an appropriate ratio as necessary.

[0055] This results in a polyurethane elastomer comprising the reaction product of the isocyanate-terminated prepolymer component and the chain-extending component.

[0056] In the reaction between the isocyanate-terminated prepolymer component and the chain extension component, more specifically, the mixture of the isocyanate-terminated prepolymer component and the chain extension component is degassed as necessary, cured in a preheated mold, and then demolded to obtain a polyurethane elastomer molded into a desired shape.

[0057] That is, the polyurethane elastomer is preferably obtained by cast molding. Therefore, the polyurethane elastomer is preferably a cast polyurethane elastomer. The polyurethane elastomer is a polyurethane elastomer molded product, and the cast polyurethane elastomer is a molded product (cast molded product) obtained by cast molding, which is an article having a predetermined shape according to the purpose and use, and is distinguished from a coating agent applied to a substrate.

[0058] The polyurethane elastomer can be heat-treated. The heat treatment temperature is, for example, 50° C. or higher, and preferably 80° C. or higher. The heat treatment temperature is, for example, 200° C. or lower, and preferably 150° C. or lower. The heat treatment time is, for example, 30 minutes or longer, and preferably 1 hour or longer. The heat treatment time is, for example, 30 hours or shorter, and preferably 20 hours or shorter.

[0059] The polyurethane elastomer can be cured. The curing temperature is, for example, 10° C. or more, preferably 20° C. or more. The curing temperature is, for example, 50° C. or less, preferably 40° C. or less. The curing time is, for example, 1 hour or more, preferably 10 hours or more. The curing time is, for example, 20 days or less, preferably 10 days or less.

[0060] The Asker A hardness (based on JIS K6253-3 (2012)) of the polyurethane elastomer thus obtained is, for example, 80A or more, preferably 90A or more, and more preferably 95A or more.

[0061] The polyurethane elastomer may contain known additives in addition to the reaction product of the isocyanate group-terminated prepolymer component and the chain extension component, if necessary. That is, the polyurethane elastomer may be a polyurethane elastomer composition.

[0062] Examples of additives include antioxidants, heat stabilizers, UV absorbers, light stabilizers, antiblocking agents, release agents, pigments, dyes, lubricants, fillers, hydrolysis inhibitors, rust inhibitors, and bluing agents. The amount of additives added is appropriately set depending on the purpose and application. In addition, additives can be appropriately added during synthesis of the isocyanate-terminated prepolymer and during the chain extension reaction depending on the purpose and application.

[0063] In the polyurethane elastomer, the primary reaction product contained in the isocyanate-terminated prepolymer component contains a reaction product of a polyisocyanate component and a macropolyol component containing a polycarbonate polyol, and the chain extension component contains 3,3'-dichloro-4,4'-diphenylmethanediamine (MOCA).

[0064] In this regard, as described in Patent Document 1, when p-xylylene diisocyanate (p-XDI) is reacted with polytetramethylene ether glycol (PTMEG) to synthesize a prepolymer, and then the prepolymer is reacted with 3,3'-dichloro-4,4-diaminodiphenylmethane (MOCA) to obtain a polyurethane elastomer, the chemical resistance (acid resistance, alkali resistance, etc.) is poor. Therefore, in order to improve the chemical resistance, it has been proposed to use polycarbonate diol (PCD) instead of PTMEG. However, the reaction between p-XDI and PCD causes the obtained prepolymer to solidify. On the other hand, the polyurethane elastomer of the present invention contains a reaction product of a polyisocyanate component containing m-xylylene diisocyanate (m-XDI), a macropolyol component containing a polycarbonate polyol, and a chain extension component containing MOCA. And, m-xylylene diisocyanate (m-XDI) has lower crystallinity than p-XDI, while MOCA improves the cohesion of the hard segments. As a result, the resulting polyurethane elastomer can have improved compression set, acid resistance, alkali resistance, and hot water resistance.

[0065] Polyurethane elastomers can be molded into any shape. In the case of thermosetting elastomers, they are molded into a desired shape during cast molding. In the case of thermoplastic elastomers, they can be molded into pellets or the like first, and then molded into a desired shape. Examples of molding methods include thermal compression molding, injection molding, extrusion molding, and melt spinning molding. Examples of shapes after molding include plate-like, fiber-like, strand-like, film-like, sheet-like, pipe-like, bottle-like, hollow, box-like, and button-like.

[0066] The uses of the molded products are not particularly limited, but include, for example, transparent hard plastics, films, sheets, bands, belts, tubes, blades, speakers, sensors, outsoles, threads, fibers, nonwoven fabrics, cosmetics, shoe products, heat insulation materials, seal materials, tape materials, solar power generation materials, robot materials, android materials, wearable materials, clothing products, sanitary products, cosmetics, furniture products, food packaging materials, sports products, leisure products, medical products, nursing care products, housing materials, acoustic materials, lighting materials, vibration-proof materials, soundproof materials, daily necessities, miscellaneous goods, cushions, bedding, stress absorbing materials, stress relaxation materials, automobile interior materials, automobile exterior materials, railway materials, aircraft materials, optical materials, OA equipment materials, miscellaneous surface protection materials, semiconductor encapsulants, health equipment, eyeglass lenses, toys, packing, cable sheaths, wire harnesses, telecommunication cables, automobile wiring, computer wiring, industrial products, shock absorbing materials and semiconductor products. The uses of the molded products are preferably industrial rolls that require wear resistance. EXAMPLES

[0067] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited thereto. Note that "parts" and "%" are based on mass unless otherwise specified. In addition, the specific numerical values ​​of the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit value (numerical value defined as "less than or equal to" or "less than") or lower limit value (numerical value defined as "more than or equal to" or "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Form for carrying out the invention".

[0068] <Synthesis Example (Synthesis of Isocyanate-Terminated Prepolymer Component)> Synthesis Example 1 In a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, 27.9 parts by mass of m-XDI (1,3-xylylene diisocyanate, trade name "Takenate 500", manufactured by Mitsui Chemicals, Inc.) and 72.1 parts by mass of PCD1000 (polycarbonate diol, trade name: UH-100W, manufactured by Ube Industries, Ltd.) having a number average molecular weight of 1000 were charged, and reacted at 80°C under a nitrogen atmosphere until the isocyanate group content reached 6.0% by mass, thereby obtaining an isocyanate group-terminated prepolymer component. The equivalent ratio (NCO / OH) of the isocyanate group in m-XDI to the hydroxyl group (OH) in PCD1000 was 2.0.

[0069] Synthesis Example 2 In a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, 33.2 parts by mass of m-XDI, 40.1 parts by mass of PCD1000 having a number average molecular weight of 1000, and 26.7 parts by mass of PCD500 (polycarbonate diol, product name: UH-50, manufactured by Ube Industries, Ltd.) having a number average molecular weight of 500 were charged, and reacted at 80°C under a nitrogen atmosphere until the isocyanate group content reached 7.0% by mass, to obtain an isocyanate group-terminated prepolymer component. The equivalent ratio (NCO / OH) of the isocyanate group in m-XDI to the hydroxyl groups (OH) in PCD1000 and PCD500 was 2.0.

[0070] Synthesis Example 3 In a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, 20.1 parts by mass of m-XDI, 14.4 parts by mass of PCD1000 having a number average molecular weight of 1000, and 65.5 parts by mass of PCD2000 (polycarbonate diol, product name: UH-200W, manufactured by Ube Industries, Ltd.) having a number average molecular weight of 2000 were charged, and reacted at 80°C under a nitrogen atmosphere until the isocyanate group content reached 5.0% by mass, to obtain an isocyanate group-terminated prepolymer component. The equivalent ratio (NCO / OH) of the isocyanate group in m-XDI to the hydroxyl groups (OH) in PCD1000 and PCD2000 was 2.3.

[0071] Synthesis Example 4 In a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, 24.8 parts by mass of m-XDI and 75.2 parts by mass of PCD1000 having a number average molecular weight of 1000 were charged, and reacted at 80°C under a nitrogen atmosphere until the isocyanate group content reached 4.8% by mass, to obtain an isocyanate-terminated prepolymer component. The equivalent ratio (NCO / OH) of the isocyanate group in m-XDI to the hydroxyl group (OH) in PCD1000 was 1.75.

[0072] Synthesis Example 5 In a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, 32.2 parts by mass of m-XDI and 67.8 parts by mass of PCD1000 having a number average molecular weight of 1000 were charged, and reacted at 80°C under a nitrogen atmosphere until the isocyanate group content reached 8.7% by mass, to obtain an isocyanate-terminated prepolymer component. The equivalent ratio (NCO / OH) of the isocyanate group in m-XDI to the hydroxyl group (OH) in PCD1000 was 2.5.

[0073] Synthesis Example 6 In a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, 27.7 parts by mass of p-XDI (1,4-xylylene diisocyanate, manufactured by Mitsui Chemicals) and 72.3 parts by mass of PTMEG1000 (polytetramethylene ether glycol, product name: PTMG1000, manufactured by Mitsubishi Chemical) having a number average molecular weight of 1000 were charged, and reacted at 80°C under a nitrogen atmosphere until the isocyanate group content reached 5.7% by mass, thereby obtaining an isocyanate group-terminated prepolymer component. The equivalent ratio (NCO / OH) of the isocyanate group in p-XDI to the hydroxyl group (OH) in PTMEG1000 was 2.0.

[0074] Synthesis Example 7 27.7 parts by mass of p-XDI and 72.1 parts by mass of PCD1000 with a number average molecular weight of 1000 were charged into a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, and reacted at 80°C under a nitrogen atmosphere until the isocyanate group content reached 6.0% by mass, but solidification occurred and no isocyanate-terminated prepolymer component was obtained. The equivalent ratio (NCO / OH) of the isocyanate group in p-XDI to the hydroxyl group (OH) in PCD1000 was 2.0.

[0075] Synthesis Example 8 27.7 parts by mass of m-XDI and 72.3 parts by mass of PTMEG1000 having a number average molecular weight of 1000 were charged into a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, and reacted at 80°C under a nitrogen atmosphere until the isocyanate group content reached 5.7% by mass, to obtain an isocyanate-terminated prepolymer component. The equivalent ratio (NCO / OH) of the isocyanate group in m-XDI to the hydroxyl group (OH) in PTMEG1000 was 2.0.

[0076] Synthesis Example 9 In a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, 42.3 parts by mass of m-XDI and 57.7 parts by mass of PCD500 with a number average molecular weight of 500 were charged and reacted at 80°C under a nitrogen atmosphere until the isocyanate group content reached 9.4% by mass, but solidification occurred and no isocyanate-terminated prepolymer component was obtained. The equivalent ratio (NCO / OH) of the isocyanate group in m-XDI to the hydroxyl group (OH) in PCD500 was 2.0.

[0077] Synthesis Example 10 In a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, 18.1 parts by mass of m-XDI and 81.9 parts by mass of PCD2000 with a number average molecular weight of 2000 were charged, and reacted under a nitrogen atmosphere at 80°C until the isocyanate group content reached 4.6% by mass, to obtain an isocyanate-terminated prepolymer component. The equivalent ratio (NCO / OH) of the isocyanate group in m-XDI to the hydroxyl group (OH) in PCD2000 was 2.4.

[0078] Examples and Comparative Examples The isocyanate group-terminated prepolymer component (prepolymer) of each synthesis example shown in Table 1 was heated to 80°C. The chain extender shown in Table 2 was heated to 120°C. The prepolymer and the chain extender were mixed in a ratio such that the equivalent ratio (active hydrogen group / NCO) was 0.90. Next, these mixtures were poured into a mold whose temperature had been adjusted to 110°C in advance, and cured in an oven at 110°C for 2 hours to obtain a polyurethane elastomer. The polyurethane elastomer was also demolded from the mold. Thereafter, the polyurethane elastomer was heat-treated in an oven at 110°C for 16 hours. As a result, a sheet-shaped polyurethane elastomer was obtained. At this time, in Comparative Example 4 and Comparative Example 6, the viscosity increased immediately after mixing the prepolymer and the chain extender, and it was not possible to pour the mixture into a mold, so molding was not possible.

[0079] The molds used were a sheet-shaped mold with a thickness of 2 mm and a button-shaped mold (cylindrical mold) with a diameter of 29 mm and a thickness of 12 mm.

[0080] <Evaluation> (1) Compression set The polyurethane elastomer prepared in a cylindrical mold was used as a measurement sample, which was set in a 25% compression tool and subjected to a certain compression strain. After 22 hours at 70°C, it was removed from the compression tool and left at 23°C for 30 minutes, after which the permanent strain was measured. The results are shown in Table 2.

[0081] (2) Acid resistance The polyurethane elastomer prepared in a 2 mm sheet mold was punched out into strips of 8 mm width x 20-35 mm length to prepare the measurement samples, and the weight before the test (W1) and the weight after immersion test in 10% hydrochloric acid at 23°C for one week (W2) were measured. The acid resistance was evaluated based on the weight change before and after the test (W = (W1 - W2) / W1 x 100 (unit: %)). The evaluation method was as follows: less than 0.5% was marked as "○", and 0.5% or more was marked as "×". The results are shown in Table 2.

[0082] (3) Alkali resistance The polyurethane elastomer prepared in a 2 mm sheet mold was punched out into strips of 8 mm width x 20-35 mm length to prepare the measurement samples, and the weight (W1) before the test and the weight (W2) after immersion test in 10% sodium hydroxide solution at 23°C for one week were measured. The alkali resistance was evaluated based on the weight change before and after the test (W = (W1 - W2) / W1 x 100 (unit: %)). The evaluation method was as follows: less than 0.5% was marked as "○", and 0.5% or more was marked as "×". The results are shown in Table 2.

[0083] (4) Hot water resistance The polyurethane elastomer made in a 2mm sheet mold was punched into a No. 3 test piece shape to prepare the measurement specimen. The measurement specimens were immersed in 80°C hot water for 9 days as the post-test sample (T1), and the one that was not immersed was the pre-test sample (T2). Using a tension and compression tester, a tensile test was performed according to JIS K-6400 (2012) to measure the breaking strength at the time of break. Hot water resistance was evaluated based on the change in breaking strength before and after the test (T = (T1 - T2) / T1 x 100 (unit: %)). The evaluation method was as follows: less than 20% was marked as "○", and 20% or more was marked as "×". The results are shown in Table 2.

[0084] [Table 1]

[0085] [Table 2]

Claims

1. a polyisocyanate component including m-xylylene diisocyanate; a macropolyol component comprising a polycarbonate polyol; a chain extending component comprising 3,3'-dichloro-4,4'-diphenylmethanediamine; comprising the reaction product of The number average molecular weight of the macropolyol component is more than 500 and less than 2000, The proportion of the m-xylylene diisocyanate in the polyisocyanate component is 50% by mass or more, The proportion of the polycarbonate polyol in the macropolyol component is 50% by mass or more, The proportion of the 3,3'-dichloro-4,4'-diphenylmethanediamine in the chain extending component is 50% by mass or more. Cast polyurethane elastomer.

2. 2. The cast polyurethane elastomer of claim 1, comprising a secondary reaction product of an isocyanate-terminated prepolymer component comprising a primary reaction product of said polyisocyanate component and said macropolyol component, and said chain extension component.

3. 3. The cast polyurethane elastomer according to claim 2, wherein the equivalent ratio (NCO / OH) of the isocyanate groups in the polyisocyanate component to the hydroxyl groups in the macropolyol component is greater than 1.5 and less than 3.0.

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