Polyurethane resin, elastic molded product, and method for manufacturing polyurethane resin

Abstract

A polyurethane resin according to the present invention contains the reaction product of a polyisocyanate component and a chain elongation component. The polyisocyanate component comprises a prepolymer composition containing an isocyanate group-terminated prepolymer and a free polyisocyanate monomer. The isocyanate group-terminated prepolymer contains the reaction product of bis(isocyanatomethyl)cyclohexane and macropolyol having a number-average molecular weight of 800 to 1800. The isocyanate group concentration of the prepolymer composition is greater than 12 mass% and less than 20 mass%. The chain elongation component is an aromatic diamine compound.

Description

Technical Field

[0001] The present invention relates to a polyurethane resin, an elastic molded article, and a method for producing a polyurethane resin.

Background Art

[0002] In recent years, polyurethane resins have been used as members of various industrial equipment such as polishing pads.

[0003] As such a polyurethane resin, for example, an isocyanate group-terminated prepolymer (isocyanate group content: 6.06% by mass) obtained by the reaction of 1,4-bis(isocyanatomethyl)cyclohexane and a high molecular weight polyol (polytetramethylene ether glycol), and a chain extender containing an active hydrogen group (3,3'-dichloro-4,4'-diphenylmethanediamine) have been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the above polyurethane elastomer (polyurethane resin) described in Patent Document 1 is used as, for example, a polishing pad, the durability may not be sufficient.

[0006] The present invention is a polyurethane resin, an elastic molded article, and a method for producing a polyurethane resin capable of improving durability.

Means for Solving the Problems

[0007] The present invention [1] includes a reaction product of a polyisocyanate component and a chain extender component. The polyisocyanate component consists of a prepolymer composition containing an isocyanate group-terminated prepolymer and a free polyisocyanate monomer. The isocyanate group-terminated prepolymer contains a reaction product of bis(isocyanatomethyl)cyclohexane and a macro polyol having a number average molecular weight of 800 or more and 1800 or less. The isocyanate group concentration of the prepolymer composition is more than 12% by mass and less than 20% by mass. The chain extender component is an aromatic diamine compound, and it contains a polyurethane resin.

[0008] The present invention [2] includes the polyurethane resin described in [1] above, wherein the aromatic diamine compound contains at least one selected from the group consisting of 3,3'-dichloro-4,4'-diphenylmethanediamine, dimethylthiotoluenediamine, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and diethyltoluenediamine.

[0009] The present invention [3] includes the polyurethane resin described in [1] or [2] above, wherein the bis(isocyanatomethyl)cyclohexane contains 1,4-bis(isocyanatomethyl)cyclohexane.

[0010] The present invention [4] includes the polyurethane resin described in [1] or [2] above, wherein the macro polyol is a polyether polyol and / or a polyester polyol.

[0011] The present invention [5] includes an elastic molded article provided with the polyurethane resin described in [1] or [2] above.

[0012] The present invention [6] includes a step of obtaining a polyisocyanate component including a prepolymer composition containing an isocyanate group-terminated prepolymer and a free polyisocyanate monomer by reacting bis(isocyanatomethyl)cyclohexane with a macro polyol having a number average molecular weight of 800 or more and 1800 or less such that the isocyanate groups of the bis(isocyanatomethyl)cyclohexane are in excess with respect to the hydroxyl groups of the macro polyol, and a step of reacting the polyisocyanate component with a chain extender to obtain a polyurethane resin containing a reaction product thereof, wherein the isocyanate group concentration of the prepolymer composition is more than 12% by mass and less than 20% by mass, and the chain extender is an aromatic diamine compound, and includes a method for producing a polyurethane resin.

Effects of the Invention

[0013] The polyurethane resin of the present invention contains a reaction product of a polyisocyanate component and a chain extender. The polyisocyanate component is composed of a prepolymer composition containing an isocyanate group-terminated prepolymer and a free polyisocyanate monomer. The isocyanate group-terminated prepolymer contains a reaction product of bis(isocyanatomethyl)cyclohexane and a macro polyol having a number average molecular weight of 800 or more and 1800 or less. The isocyanate group concentration of the prepolymer composition is more than 12% by mass and less than 20% by mass, and the chain extender is an aromatic diamine compound, and includes a polyurethane resin.

[0014] Therefore, the polyurethane resin of the present invention can improve durability.

[0015] The elastic molded article of the present invention includes the above polyurethane resin. Therefore, the elastic molded article of the present invention can improve durability.

[0016] Further, according to the method for producing a polyurethane resin of the present invention, a polyurethane resin capable of improving durability can be obtained.

Modes for Carrying Out the Invention

[0017] The polyurethane resin of the present invention contains a reaction product of a polyisocyanate component and a chain extender component. Preferably, the polyurethane resin of the present invention consists of a reaction product of a polyisocyanate component and a chain extender component.

[0018] <Polyisocyanate component> The polyisocyanate component consists of a prepolymer composition containing an isocyanate group-terminated prepolymer and a free polyisocyanate monomer.

[0019] The isocyanate group-terminated prepolymer contains a reaction product of bis(isocyanatomethyl)cyclohexane and a macro polyol. Preferably, the isocyanate group-terminated prepolymer consists of a reaction product of bis(isocyanatomethyl)cyclohexane and a macro polyol.

[0020] (Bis(isocyanatomethyl)cyclohexane) Examples of bis(isocyanatomethyl)cyclohexane include 1,4-bis(isocyanatomethyl)cyclohexane and 1,3-bis(isocyanatomethyl)cyclohexane.

[0021] Bis(isocyanatomethyl)cyclohexane preferably contains 1,4-bis(isocyanatomethyl)cyclohexane. More preferably, bis(isocyanatomethyl)cyclohexane consists of 1,4-bis(isocyanatomethyl)cyclohexane.

[0022] 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI) has stereoisomers. Examples of the stereoisomers include cis-1,4-bis(isocyanatomethyl)cyclohexane (hereinafter referred to as cis 1,4 form) and trans-1,4-bis(isocyanatomethyl)cyclohexane (hereinafter referred to as trans 1,4 form).

[0023] The content ratio of the trans-1,4 isomer is, for example, 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, particularly preferably 85 mol% or more, based on the total amount of the cis-1,4 isomer and the trans-1,4 isomer. Also, for example, it is 100 mol% or less, preferably 95 mol% or less, more preferably 90 mol% or less, still more preferably 87.5 mol% or less.

[0024] 1,4-bis(isocyanatomethyl)cyclohexane is produced by a known method. Methods for producing 1,4-bis(isocyanatomethyl)cyclohexane are described, for example, in International Publication No. WO2009 / 051114 and International Publication No. WO2019 / 069802.

[0025] Bis(isocyanatomethyl)cyclohexane may be a modified product as long as the effects of the present invention are not inhibited. Examples of the modified product include uretdione-modified products, isocyanurate-modified products, iminooxadiazinedione, biuret-modified products, allophanate-modified products, polyol adducts, oxadiazinetrione-modified products, and carbodiimide-modified products. These can be used alone or in combination of two or more. Bis(isocyanatomethyl)cyclohexane is preferably unmodified.

[0026] (Macropolyol) Macropolyol is an organic compound having two or more hydroxyl groups in the molecule and a relatively high molecular weight. Relatively high molecular weight means that the number average molecular weight exceeds 300. That is, macropolyol is a high molecular weight polyol.

[0027] Examples of the macro polyol include polyether polyol, polyester polyol, polycarbonate polyol, polyurethane polyol, epoxy polyol, vegetable oil polyol, polyolefin polyol, acrylic polyol, and vinyl monomer-modified polyol. These can be used alone or in combination of two or more. Preferred examples of the macro polyol include polyether polyol and / or polyester polyol.

[0028] Examples of the polyether polyol include polyoxyalkylene polyol. Examples of the polyoxyalkylene polyol include polyoxyalkylene (C2-3) polyol and polytetramethylene ether polyol (PTMEG). These can be used alone or in combination of two or more. Preferred examples of the polyether polyol include polytetramethylene ether polyol.

[0029] Examples of the polyester polyol include condensation polyester polyol and ring-opening polyester polyol. Examples of the condensation polyester polyol include adipate-based polyester polyol and phthalate-based polyester polyol. Examples of the adipate-based polyester polyol include polybutylene adipate and polyethylene adipate. Examples of the ring-opening polyester polyol include lactone-based polyester polyol. Examples of the lactone-based polyester polyol include polycaprolactone polyol. These can be used alone or in combination of two or more. Preferred examples of the polyester polyol include polyethylene adipate and polycaprolactone polyol.

[0030] The number average molecular weight of the macro polyol is 800 or more, preferably 900 or more, more preferably 950 or more, still more preferably 975 or more. Further, the number average molecular weight of the macro polyol is, for example, 1800 or less, preferably 1500 or less, more preferably 1250 or less, still more preferably 1100 or less, particularly preferably 1050 or less. When the number average molecular weight of the macro polyol is less than the above lower limit or exceeds the above upper limit, the polyurethane resin cannot achieve improved durability.

[0031] The macro polyol has a single molecular weight distribution. That is, the macro polyol is preferably used alone. Further, the macro polyol can have a plurality of macro polyols having a single molecular weight distribution. In this case, the macro polyol has a plurality of macro polyols having a single molecular weight distribution within the range of the number average molecular weight of the above macro polyol. That is, when the macro polyol has a plurality of macro polyols having a single molecular weight distribution, even if the number average molecular weight obtained by summing up the plurality of macro polyols falls within the above range, a macro polyol having a number average molecular weight less than the above lower limit or exceeding the above upper limit of the number average molecular weight of the above macro polyol is not included.

[0032] When the macro polyol contains a polyether polyol, the content ratio of the polyether polyol is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, particularly preferably 100% by mass, based on the total amount of the macro polyol. In other words, the macro polyol particularly preferably consists of a polyether polyol.

[0033] When the macro polyol contains a polyester polyol, the content ratio of the polyester polyol is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, particularly preferably 100% by mass, based on the total amount of the macro polyol. In other words, the macro polyol particularly preferably consists of a polyester polyol.

[0034] When the macro polyol has both a polyether polyol and a polyester polyol, their contents are appropriately set according to the purpose and application.

[0035] (Method for Producing Isocyanate Group-Terminated Prepolymer (Prepolymer Composition)) The isocyanate group-terminated prepolymer is synthesized in the step of obtaining a polyisocyanate component, which includes reacting bis(isocyanatomethyl)cyclohexane with a macro polyol so that the isocyanate groups of bis(isocyanatomethyl)cyclohexane are in excess relative to the hydroxyl groups of the macro polyol, to obtain a prepolymer composition containing an isocyanate group-terminated prepolymer and a free polyisocyanate monomer.

[0036] In the step of obtaining the polyisocyanate component, bis(isocyanatomethyl)cyclohexane is reacted with a macro polyol to synthesize an isocyanate group-terminated prepolymer.

[0037] Specifically, the above-mentioned bis(isocyanatomethyl)cyclohexane and the above-mentioned macro polyol are mixed and reacted.

[0038] As a method for reacting bis(isocyanatomethyl)cyclohexane with a macro polyol, a known polymerization method (for example, bulk polymerization and solution polymerization) is selected. Preferably, bulk polymerization is mentioned.

[0039] In this reaction, the blending ratio of bis(isocyanatomethyl)cyclohexane and the macro polyol is adjusted so that the isocyanate groups of bis(isocyanatomethyl)cyclohexane are in excess relative to the hydroxyl groups of the macro polyol.

[0040] Specifically, the equivalent ratio R1 (isocyanate group / active hydrogen group) of the isocyanate groups in bis(isocyanatomethyl)cyclohexane to the hydroxyl groups in the macro polyol exceeds 1, for example, 2.0 or more, preferably 2.5 or more, more preferably 3.0 or more, still more preferably 3.5 or more, particularly preferably 4.0 or more, especially preferably 4.25 or more, and most preferably 4.5 or more. Also, for example, it is 11.0 or less, preferably 8.0 or less, more preferably 7.0 or less, still more preferably 6.0 or less, particularly preferably 5.5 or less. The terminal functional group of the reaction product obtained in such a case is an isocyanate group. That is, an isocyanate group-terminated prepolymer is obtained.

[0041] As reaction conditions, the reaction temperature is, for example, 20°C or more and, for example, 1500°C or less. Also, the reaction time is 1 hour or more and, for example, 20 hours or less.

[0042] In the reaction of bis(isocyanatomethyl)cyclohexane and the macro polyol, a known urethanization catalyst may be added as necessary. In the above reaction, preferably, a urethanization catalyst is added. Examples of the urethanization catalyst include amines, organometallic compounds, and potassium salts. These urethanization catalysts can be used alone or in combination of two or more. As the urethanization catalyst, preferably, an organometallic compound, more preferably an organotin compound, and still more preferably dibutyltin dilaurate (DBTDL) are mentioned.

[0043] Thereby, an isocyanate group-terminated prepolymer (specifically, the reaction solution of the isocyanate group-terminated prepolymer), which is a reaction product of bis(isocyanatomethyl)cyclohexane and the macro polyol, is obtained.

[0044] And the isocyanate group-terminated prepolymer is a polyurethane prepolymer having at least one (preferably a plurality, more preferably two) free isocyanate groups at its molecular terminals.

[0045] In the isocyanate group-terminated prepolymer, the average functionality of the isocyanate groups is, for example, 1.5 or more, preferably 1.9 or more, and is, for example, 3.0 or less, preferably 2.5 or less. In the isocyanate group-terminated prepolymer, the average functionality of the isocyanate groups is particularly preferably 2.

[0046] Also, in the reaction of bis(isocyanatomethyl)cyclohexane and a macro polyol, since the reaction is carried out such that the isocyanate groups of bis(isocyanatomethyl)cyclohexane are in excess with respect to the hydroxyl groups of the macro polyol, the reaction solution of the isocyanate group-terminated prepolymer contains a monomer of free bis(isocyanatomethyl)cyclohexane (that is, a free (unreacted) polyisocyanate monomer). That is, the reaction solution of the isocyanate group-terminated prepolymer is a prepolymer composition containing the isocyanate group-terminated prepolymer and a free polyisocyanate monomer.

[0047] The content of the isocyanate group-terminated prepolymer is, for example, 60% by mass or more, preferably 70% by mass or more, based on the polyisocyanate component.

[0048] Also, the content of the unreacted, free polyisocyanate monomer is, for example, 40% by mass or less, preferably 30% by mass or less, based on the polyisocyanate component. The content of the unreacted, free polyisocyanate monomer can be determined, for example, by HPLC measurement.

[0049] The content of isocyanate groups (i.e., isocyanate group concentration) in the prepolymer composition is, for example, more than 12% by mass, preferably 13% by mass or more, more preferably 14% by mass or more, still more preferably 15% by mass or more, particularly preferably 15.6% by mass or more, and also, for example, less than 20% by mass, preferably 19% by mass or less, more preferably 18.5% by mass or less, still more preferably 18% by mass or less. When the isocyanate group concentration is below the above lower limit or above the above upper limit, the polyurethane resin of the present invention cannot achieve improved durability. Incidentally, the content of isocyanate groups can be determined by known measurement methods. Examples of the measurement methods include titration with di-n-butylamine and FT-IR analysis.

[0050] Also, the isocyanate group equivalent of the prepolymer composition is, for example, 210 or more, preferably 233 or more, and also, for example, 351 or less, preferably 270 or less. Incidentally, the isocyanate group equivalent is synonymous with the amine equivalent and can be determined by Method A or Method B of JIS K 1603-1 (2007).

[0051] In the synthesis of the isocyanate group-terminated prepolymer, other polyisocyanates and / or low molecular weight polyols other than bis(isocyanatomethyl)cyclohexane (H6XDI) can also be reacted with H6XDI and the macro polyol as long as the effects of the present invention are not inhibited. In such a case, the prepolymer composition contains the reaction product of other polyisocyanates and low molecular weight polyols together with the reaction product of H6XDI and the macro polyol.

[0052] The other polyisocyanate is a polyisocyanate excluding bis(isocyanatomethyl)cyclohexane.

[0053] Examples of other polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates (excluding bis(isocyanatomethyl)cyclohexane), aromatic polyisocyanates, and araliphatic polyisocyanates.

[0054] Examples of aliphatic polyisocyanates include pentamethylene diisocyanate (PDI) and hexamethylene diisocyanate (HDI). Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), and methylene bis(cyclohexyl isocyanate) (H 12 MDI). Examples of aromatic polyisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), toluidine diisocyanate (TODI), and naphthalene diisocyanate (NDI). Examples of araliphatic polyisocyanates include xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI). Other polyisocyanates may be monomers or the above-described modified products. These can be used alone or in combination of two or more.

[0055] The content ratio of other polyisocyanates is, for example, 50 parts by mass or less, preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and particularly preferably 0 parts by mass, based on 100 parts by mass of bis(isocyanatomethyl)cyclohexane.

[0056] Low molecular weight polyols are organic compounds having two or more hydroxyl groups in the molecule and having a relatively low molecular weight. Relatively low molecular weight means that the number average molecular weight is 300 or less.

[0057] Low molecular weight polyols include, for example, low molecular weight diols having 2 to 6 carbon atoms.

[0058] Examples of the low molecular weight diols having 2 to 6 carbon atoms include alkane diols having 2 to 6 carbon atoms, ether diols having 2 to 6 carbon atoms, and alkene diols having 2 to 6 carbon atoms. Examples of the alkane diols having 2 to 6 carbon atoms include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol (1,4-BG), 1,3-butanediol (1,3-BG), 1,2-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 2,2-dimethyl-1,3-propanediol. Examples of the ether diols having 2 to 6 carbon atoms include diethylene glycol (DEG), triethylene glycol, and dipropylene glycol. Examples of the alkene diols having 2 to 6 carbon atoms include 1,4-dihydroxy-2-butene. These can be used alone or in combination of two or more.

[0059] For example, in the case of using the polyurethane resin for a polishing pad, the polyurethane resin may be used after being foamed. In this case, in order to facilitate foaming, preferably, a low molecular weight polyol such as diethylene glycol may be used in combination with the macro polyol.

[0060] The content ratio of the low molecular weight polyol is, for example, 50 parts by mass or less, preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and particularly preferably 0 parts by mass, based on 100 parts by mass of the macro polyol.

[0061] That is, in the prepolymer composition, the isocyanate group-terminated prepolymer is a reaction product of bis(isocyanatomethyl)cyclohexane (H6XDI) and a macro polyol, and the free polyisocyanate monomer is the H6XDI monomer.

[0062] <Chain extension component> The chain extension component is an aromatic diamine compound.

[0063] Examples of the aromatic diamine compound include 4,4'-diphenylmethanediamine, 3,3'-dichloro-4,4'-diphenylmethanediamine (hereinafter sometimes referred to as 4,4'-methylenebis(2-chloroaniline) (MOCA)), diethyltoluenediamine (DETDA), dimethylthiotoluenediamine, 4,4'-methylenebis(3-chloro-2,6-diethylaniline) (MCDEA), N,N'-di-secondary-butyl-p-phenylenediamine, 4,4'-bis(secondary-butylamino)diphenylmethane, 4,4'-bis(methylamino)diphenylmethane, trimethylene-bis(4-aminobenzoate), polytetramethylene oxide-di-p-aminobenzoate, N-phenyl-N'-isopropyl-p-phenylenediamine, and N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine. Examples of diethyltoluenediamine include 2,4-diethyltoluenediamine and 2,6-diethyltoluenediamine. Examples of dimethylthiotoluenediamine include 3,5-bis(methylthio)-2,6-toluenediamine and 3,5-bis(methylthio)-2,4-toluenediamine.

[0064] Examples of the aromatic diamine compound also include commercially available products, and more specifically, for example, Ethacure 100 (trade name, DETDA, manufactured by Albemarle Corporation) and Ethacure 300 (trade name, dimethylthiotoluenediamine, manufactured by Albemarle Corporation).

[0065] These aromatic diamine compounds can be used alone or in combination of two or more.

[0066] Preferred examples of the aromatic diamine compound include 3,3'-dichloro-4,4'-diphenylmethanediamine, dimethylthiotoluenediamine, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and diethyltoluenediamine, and more preferred examples include 3,3'-dichloro-4,4'-diphenylmethanediamine, dimethylthiotoluenediamine, and diethyltoluenediamine.

[0067] (Method for producing polyurethane resin) The polyurethane resin is obtained in the step of reacting a polyisocyanate component and a chain extender component to obtain a polyurethane resin containing their reaction product.

[0068] In the step of obtaining the polyurethane resin, the polyisocyanate component and the chain extender component are mixed, and the polyisocyanate component and the chain extender component are reacted (extension reaction) to obtain a polyurethane resin as their reaction product. That is, the polyurethane resin consists of their reaction product.

[0069] The blending ratio of the polyisocyanate component and the chain extender component is such that the equivalent ratio R2 (amino group / isocyanate group) of the isocyanate group of the isocyanate group-terminated prepolymer to the amino group in the chain extender component is, for example, 0.8 or more, preferably 0.9 or more, more preferably 0.925 or more, and, for example, 1.30 or less, preferably 1.20 or less, more preferably 1.10 or less, still more preferably 1 or less, particularly preferably 0.975 or less. The equivalent ratio R2 is particularly preferably 0.95.

[0070] Also, in the above reaction, the reaction temperature is, for example, 25°C or higher, preferably 50°C or higher, and, for example, 200°C or lower, preferably 150°C or lower. Also, the reaction time is, for example, 5 minutes or longer, preferably 1 hour or longer, more preferably 8 hours or longer, still more preferably 12 hours or longer, and, for example, 72 hours or shorter, preferably 48 hours or shorter, more preferably 24 hours or shorter.

[0071] Thereby, the polyisocyanate component and the chain extender component are reacted to produce a polyurethane resin.

[0072] Also, in this method, the polyurethane resin can be heat-treated as necessary. The heat treatment temperature is, for example, 50°C or higher, preferably 80°C or higher, more preferably 100°C or higher, and, for example, 200°C or lower, preferably 150°C or lower. Also, the heat treatment time is, for example, 30 minutes or longer, preferably 1 hour or longer, and, for example, 30 hours or shorter, preferably 20 hours or shorter.

[0073] Also, the polyurethane resin can be aged. The aging temperature is, for example, 10°C or higher, preferably 20°C or higher, and, for example, 50°C or lower, preferably 40°C or lower. Also, the aging time is, for example, 1 hour or longer, preferably 10 hours or longer, and, for example, 50 days or shorter, preferably 30 days or shorter.

[0074] The polyurethane resin can contain known additives as necessary. Examples of the additives include antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, anti-blocking agents, mold release agents, pigments, dyes, lubricants, fillers, hydrolysis inhibitors, rust preventives, and bluing agents. The addition amount of the additives is appropriately set according to the purpose and application.

[0075] Note that the timing of adding the additives is not particularly limited. For example, in the step of obtaining the polyisocyanate component, when synthesizing the isocyanate group-terminated prepolymer, and / or after synthesizing the isocyanate group-terminated prepolymer, the additives can also be added. Also, in the step of obtaining the polyurethane resin, the additives can be added to the polyisocyanate component and / or the chain extender component. And, in the step of obtaining the polyurethane resin, the additives can be added to the mixture of the polyisocyanate component and the chain extender component.

[0076] And, the above-described polyurethane resin can be suitably used for the production of elastic molded articles.

[0077] <Elastic Molded Article> The elastic molded article of the present invention comprises a polyurethane resin.

[0078] Examples of the elastic molded article include polyurethane elastomers. Examples of the polyurethane elastomer include TPU (thermoplastic polyurethane resin) and TSU (thermosetting polyurethane resin). Preferably, the elastic molded article is TSU (thermosetting polyurethane resin).

[0079] The elastic molded article is obtained by molding a polyurethane resin by a known molding method.

[0080] Examples of the molding method include casting. Examples of the shape after molding include plate-like, fibrous, strand-like, film-like, sheet-like, pipe-like, bottle-like, hollow-like, box-like, and button-like. The elastic molded article is preferably obtained by casting. Therefore, the elastic molded article is preferably a cast polyurethane elastomer.

[0081] Such a cast polyurethane elastomer is obtained, for example, in the production of the above-mentioned polyurethane resin by defoaming a mixture of a polyisocyanate component and a chain extender as necessary, injecting it into a preheated mold, then curing it, and demolding it.

[0082] The thickness of the elastic molded article is, for example, 1 cm or more, preferably 2 cm or more, and, for example, 20 cm or less, preferably 10 cm or less.

[0083] And the cast polyurethane elastomer is a molded article obtained by casting (cast molded article), an article having a predetermined shape according to the purpose and use, and is distinguished from a coating agent applied to an object to be coated.

[0084] The elastic molded product contains the above polyurethane resin. Therefore, the elastic molded product can improve durability. Here, durability refers to deflection suppression, low heat generation, softening suppression at 50°C to 100°C, and elongation (elongation at break).

[0085] <Function and Effect> The above polyurethane resin contains a reaction product of a polyisocyanate component and a chain extender. The polyisocyanate component consists of a prepolymer composition containing an isocyanate group-terminated prepolymer and a free polyisocyanate monomer. The isocyanate group-terminated prepolymer contains a reaction product of bis(isocyanatomethyl)cyclohexane and a macro polyol having a number average molecular weight of 800 or more and 1800 or less. The isocyanate group concentration of the prepolymer composition is more than 12% by mass and less than 20% by mass. The chain extender is an aromatic diamine compound, and it contains a polyurethane resin. Therefore, the polyurethane resin can improve durability (deflection suppression, low heat generation, softening suppression at 50°C to 100°C, and elongation (elongation at break)).

[0086] On the other hand, in the above polyurethane resin, when the number average molecular weight of the macro polyol is less than 800, the effect of softening suppression at 50°C to 100°C cannot be obtained.

[0087] Also, in the above polyurethane resin, when the number average molecular weight of the macro polyol exceeds 1800, the effect of deflection suppression cannot be obtained.

[0088] Also, in the above polyurethane resin, when the isocyanate group concentration of the prepolymer composition is 12% by mass or less, the effects of deflection suppression and softening suppression at 50°C to 100°C cannot be obtained.

[0089] Also, in the above polyurethane resin, when the isocyanate group concentration of the prepolymer composition is 20% by mass or more, the effect of elongation (elongation at break) cannot be obtained.

[0090] In addition, in the above polyurethane resin, when the chain extender component is not an aromatic diamine compound, the effect of suppressing deflection cannot be obtained.

[0091] In addition, in the above polyurethane resin, when the number average molecular weight of the macro polyol is less than 800 and the isocyanate group concentration of the prepolymer composition is 12% by mass or less, the effects of suppressing deflection, suppressing softening at 50°C to 100°C, and low heat generation cannot be obtained.

[0092] In the above polyurethane resin, when the number average molecular weight of the macro polyol is 800 or more and 1800 or less, and the isocyanate group concentration of the prepolymer composition exceeds 12% by mass and is less than 20% by mass, it is possible to suppress deflection, achieve low heat generation, suppress softening at 50°C to 100°C, and improve elongation (elongation at break).

[0093] The elastic molded product of the present invention includes the above polyurethane resin. Therefore, the elastic molded product of the present invention can improve durability.

[0094] Moreover, according to the method for producing the polyurethane resin of the present invention, a polyurethane resin capable of improving durability can be obtained.

[0095] <Use> The above polyurethane resin and the above elastic molded product are polyurethane resins capable of improving durability as described above. Therefore, they are suitably used in various industrial fields. Specifically, abrasive pads, transparent hard plastics, waterproof materials, potting agents, inks, binders, films, sheets, bands, belts, shoe press belts, tubes, rollers, mecanum rollers, blades, speakers, sensors, outsoles, threads, fibers, non-woven fabrics, cosmetics, footwear, heat insulating materials, sealing materials, tape materials, sealing materials, solar power generation members, robot members, android members, wearable members, clothing, sanitary products, cosmetic products, furniture products, food packaging members, sports products, leisure products, medical products, nursing care products, housing members, acoustic members, lighting members, vibration-proof members, sound-proof members, daily necessities, sundries, cushions, bedding, stress absorbing materials, stress relieving materials, automotive interior materials, automotive exterior materials, railway members, aircraft members, optical members, members for OA equipment, surface protection members for sundries, semiconductor encapsulants, self-healing materials, health appliances, spectacle lenses, toys, packings, cable sheaths, wire harnesses, telecommunication cables, automotive wiring, computer wiring, industrial products, impact absorbing materials, semiconductor products, various members for wet blasting machines, bump stopper materials, corrugated roll materials for water squeezing, blade materials for wind power generation, and bridge bearings. The above polyurethane resin and the above elastic molded product are preferably suitably used for abrasive pads.

Examples

[0096] Examples are shown below to explain the present invention more specifically, but the present invention is not limited thereto. Specific numerical values such as the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values (numerical values defined as "below" and "less than") or lower limit values (numerical values defined as "above" and "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Mode for Carrying Out the Invention". In addition, "parts" and "%" are based on mass unless otherwise specified.

[0097] <Synthesis of 1,4-bis(isocyanatomethyl)cyclohexane> Production Example 1 In accordance with the description of Production Example 3 in International Publication WO2019 / 069802, 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI) was obtained. As a result of measuring the purity of 1,4-H6XDI by gas chromatography, it was 99.9%. Also, the hue by APHA measurement was 5. Also, 13 The ratio of the trans form and the cis form measured by 13C-NMR measurement was 86 mol% of the trans form and 14 mol% of the cis form.

[0098] <Production of polyurethane resin and elastic molded article> Examples 1 to 10 and Comparative Examples 1 to 10 [Step of obtaining polyisocyanate component] The polyisocyanate and macro polyol described in each table and the urethanization catalyst (organometallic catalyst (DBTDL)) based on the formulation described in each table were reacted at 80 °C in a nitrogen atmosphere until the isocyanate group concentration reached the value described in each table. The blending ratio of the polyisocyanate and the macro polyol was adjusted so that the equivalent ratio R1 (isocyanate group / hydroxyl group) of the isocyanate group in the polyisocyanate component to the hydroxyl group in the polyol component became the value described in each table. Thereby, an isocyanate group-terminated prepolymer was synthesized, and a reaction solution containing the isocyanate group-terminated prepolymer was obtained. Next, 0.5% by mass of a hindered phenol-based antioxidant (trade name Irganox 1076, manufactured by BASF) and 0.3% by mass of a phosphite-based antioxidant (trade name JPP-100, manufactured by Johoku Chemical Industry Co., Ltd.) were added to this reaction solution. Thereby, a polyisocyanate component (prepolymer composition) was obtained.

[0099] Note that the content of the urethanization catalyst described in each table means the content of the organometallic catalyst with respect to the isocyanate group-terminated prepolymer.

[0100] [Step of obtaining polyurethane resin] The above-mentioned polyisocyanate component and the chain extender components described in each table were mixed at an equivalent ratio R2(NH2 / NCO) of the amino groups in the chain extender component to the isocyanate groups of the polyisocyanate component to obtain a mixture of the polyisocyanate component and the chain extender component. The mixture was poured into a preheated mold at 110°C, cured under the curing conditions described in each table, and then demolded to obtain a cured urethane resin. Thereby, an elastic molded product was manufactured.

[0101] <Evaluation> [D hardness (deflection suppression)] The D hardness of the elastic molded products of each example and each comparative example was measured in accordance with JIS K 7312 (1996). The results are shown in Tables 1 to 4.

[0102] [Tensile properties (tensile strength and elongation at break)] (Elongation (elongation at break)) The tensile properties of the elastic molded products of each example and each comparative example were measured using a universal tensile testing machine (205N manufactured by Intesco Co., Ltd.) in accordance with JIS K 7312 (1996). That is, the elastic molded product was cut to obtain a No. 3 dumbbell test piece. Then, under the condition of a tensile speed of 500 mm / min, the tensile strength (MPa) and the elongation at break (%) were measured. The results are shown in Tables 1 to 4.

[0103] [E´ (storage modulus)] (deflection suppression) The dynamic viscoelastic spectrum of the elastic molded product was measured using a dynamic viscoelastic measuring device (manufactured by IT Measurement & Control Co., Ltd., model: DVA-220) under the conditions of a measurement start temperature of -100°C, a heating rate of 5°C / min, a tensile mode, a gauge length of 20 mm, a static / dynamic stress ratio of 1.8, and a measurement frequency of 10 Hz. Then, E´ (E´@50°C) at 50°C and E´ (E´@100°C) at 100°C were calculated. In addition, the ratio of E´@100°C / E´@50°C was calculated as an index for softening suppression from 50°C to 100°C. The results are shown in Tables 1 to 4.

[0104] [tanδ (loss factor)] (low heat generation) As an index of low heat generation, the loss factor (tanδ) of the elastic molded products of each example and each comparative example was calculated. More specifically, in the dynamic viscoelastic spectrum described above, the loss factors (tanδ) at 50°C and 100°C were calculated (tanδ@50°C and tanδ@100°C, respectively). In addition, as an index of softening suppression from 50°C to 100°C, the ratio of tanδ@100°C / tanδ@50°C was calculated. The results are shown in Tables 1 to 4.

[0105] Note that for Comparative Example 9, since the value of elongation at break was low and it was judged to be inappropriate, the measurement of E´ (storage elastic modulus) and tanδ@100°C could not be performed.

[0106]

Table 1

[0107]

Table 2

[0108]

Table 3

[0109]

Table 4

[0110] The details of the abbreviations in the table are as follows. 1,4-H6XDI: 1,4-bis(isocyanatomethyl)cyclohexane T-80: Cosmonate T-80 (trade name, tolylene diisocyanate) T-100: Cosmonate T-100 (trade name, toluene-2,4-diisocyanate) PTMEG: polytetramethylene ether glycol DEG: diethylene glycol PCL: polycaprolactone diol, number average molecular weight (Mn) 1000 1,4-BG: 1,4-butanediol 1,3-BG: 1,3-butanediol MOCA: 4,4'-methylenebis(2-chloroaniline) E-100: Ethacure 100 (trade name, diethyltoluenediamine) E300: Ethacure 300 (trade name, dimethylthiotoluenediamine) MCDEA: 4,4'-methylenebis(3-chloro-2,6-diethylaniline) DBTDL: Dibutyltin dilaurate

[0111] Note that the above invention is provided as an exemplary embodiment of the present invention, but this is merely an example and should not be construed in a limiting manner. Modifications of the present invention that are obvious to those skilled in the art are included in the scope of the claims described below.

Industrial Applicability

[0112] The polyurethane resin, elastic molded article, and method for producing a polyurethane resin of the present invention are suitably used in various industrial fields.

Claims

1. A polyurethane resin comprising a reaction product of a polyisocyanate component and a chain extender component, wherein the polyisocyanate component consists of a prepolymer composition containing an isocyanate group-terminated prepolymer and a free polyisocyanate monomer, the isocyanate group-terminated prepolymer contains a reaction product of bis(isocyanatomethyl)cyclohexane and a macro polyol having a number average molecular weight of 800 or more and 1800 or less, the bis(isocyanatomethyl)cyclohexane contains 1,4-bis(isocyanatomethyl)cyclohexane, the isocyanate group concentration of the prepolymer composition is more than 12% by mass and less than 20% by mass, and the chain extender component is an aromatic diamine compound.

2. The polyurethane resin according to claim 1, wherein the aromatic diamine compound contains at least one selected from the group consisting of 3,3'-dichloro-4,4'-diphenylmethanediamine, dimethylthiotoluenediamine, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and diethyltoluenediamine.

3. The polyurethane resin according to claim 1, wherein the macro polyol is a polyether polyol and / or a polyester polyol.

4. An elastic molded article comprising the polyurethane resin according to claim 1.

5. A process for producing a polyurethane resin, comprising reacting bis(isocyanatomethyl)cyclohexane and a macro polyol having a number average molecular weight of 800 or more and 1800 or less so that the isocyanate groups of the bis(isocyanatomethyl)cyclohexane are in excess with respect to the hydroxyl groups of the macro polyol, to obtain a polyisocyanate component containing a prepolymer composition containing an isocyanate group-terminated prepolymer and a free polyisocyanate monomer, and reacting the polyisocyanate component with a chain extender component to obtain a polyurethane resin containing their reaction product, wherein the bis(isocyanatomethyl)cyclohexane contains 1,4-bis(isocyanatomethyl)cyclohexane, the isocyanate group concentration of the prepolymer composition is more than 12% by mass and less than 20% by mass, and the chain extender component is an aromatic diamine compound.

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