Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
  • C08G18/75—Polyisocyanates or polyisothiocyanates cyclic cycloaliphatic

Definitions

• the present invention relates to a polyurethane elastomer and a method for producing a polyurethane elastomer.
• Polyurethane elastomers have excellent mechanical strength and abrasion resistance, and are easy to process, so they are widely used in various industrial equipment.
• a polyurethane elastomer for example, a polyurethane elastomer obtained by reacting 1,4-bis(isocyanatomethyl)cyclohexane with polytetramethylene ether glycol to obtain an isocyanate-terminated prepolymer, and then reacting the obtained isocyanate-terminated prepolymer with 1,4-butanediol has been proposed (see, for example, Example 1 of Patent Document 1).
• polyurethane elastomers are required to have even greater transparency depending on the application.
• the present invention aims to provide a polyurethane elastomer with excellent transparency and a method for producing the polyurethane elastomer.
• the present invention is a polyurethane elastomer containing a reaction product of an isocyanate-terminated prepolymer and a curing agent, the isocyanate-terminated prepolymer containing a reaction product of a polyisocyanate component containing bis(isocyanatomethyl)cyclohexane and a polyol component containing a high molecular weight polyol and a low molecular weight polyol, and the low molecular weight polyol contains 1,4-butanediol.
• the present invention [2] includes the polyurethane elastomer described in [1] above, in which the number average molecular weight of the high molecular weight polyol is 400 or more, and the number average molecular weight of the low molecular weight polyol is less than 400.
• the present invention [3] includes the polyurethane elastomer described in [1] or [2] above, in which the number average molecular weight of the high molecular weight polyol is 1200 or more and 3200 or less.
• the present invention [4] contains the polyurethane elastomer described in any one of [1] to [3] above, in which the content of the low molecular weight polyol is 0.05 parts by mass or more and 1.50 parts by mass or less per 100 parts by mass of the high molecular weight polyol.
• the present invention [5] includes a polyurethane elastomer according to any one of [1] to [4] above, in which the urethane group concentration is 1.3 mmol/g or more and 2.5 mmol/g or less.
• the present invention [6] includes a polyurethane elastomer described in any one of [1] to [5] above, which has a haze of 80% or less.
• the present invention [7] includes the polyurethane elastomer described in any one of [1] to [6] above, in which the curing agent contains 1,4-butanediol and the content of 1,4-butanediol relative to the curing agent is 80 mass% or more.
• the present invention [8] is a method for producing a polyurethane elastomer, comprising a first step of reacting a polyisocyanate component and a polyol component to produce an isocyanate-terminated prepolymer, and a second step of reacting the isocyanate-terminated prepolymer and a curing agent to produce a polyurethane elastomer, the polyisocyanate component including bis(isocyanatomethyl)cyclohexane, the polyol component including a high molecular weight polyol and a low molecular weight polyol, and the low molecular weight polyol including 1,4-butanediol.
• the polyurethane elastomer of the present invention contains a reaction product of an isocyanate-terminated prepolymer and a curing agent.
• the polyol component of the isocyanate-terminated prepolymer contains a low molecular weight polyol, and the low molecular weight polyol contains 1,4-butanediol. This improves transparency.
• the method for producing a polyurethane elastomer of the present invention comprises a first step of reacting a polyisocyanate component with a polyol component to produce an isocyanate-terminated prepolymer, and a second step of reacting an isocyanate-terminated prepolymer with a curing agent to produce a polyurethane elastomer.
• the polyol component also contains a low molecular weight polyol that includes 1,4-butanediol. This improves transparency.
• Polyurethane elastomers are cured polyurethanes that contain the reaction product of an isocyanate-terminated prepolymer and a curing agent.
• the isocyanate-terminated prepolymer comprises a reaction product of a polyisocyanate component and a polyol component.
• the isocyanate-terminated prepolymer preferably comprises a reaction product of a polyisocyanate component and a polyol component.
• the polyisocyanate component contains bis(isocyanatomethyl)cyclohexane as an essential component.
• bis(isocyanatomethyl)cyclohexane examples include 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane.
• a preferred example of bis(isocyanatomethyl)cyclohexane is 1,4-bis(isocyanatomethyl)cyclohexane.
• 1,4-bis(isocyanatomethyl)cyclohexane has the stereoisomers cis-1,4-bis(isocyanatomethyl)cyclohexane and trans-1,4-bis(isocyanatomethyl)cyclohexane.
• the total amount of cis-1,4-bis(isocyanatomethyl)cyclohexane and trans-1,4-bis(isocyanatomethyl)cyclohexane is 100 mol%.
• the content of trans-1,4-bis(isocyanatomethyl)cyclohexane is, for example, 60 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 85 mol% or more, and for example, 99.8 mol% or less, preferably 99 mol% or less, more preferably 96 mol% or less, even more preferably 90 mol% or less.
• the content of cis-1,4-bis(isocyanatomethyl)cyclohexane is, for example, 0.2 mol% or more, preferably 1 mol% or more, more preferably 4 mol% or more, even more preferably 10 mol% or more, and, for example, 40 mol% or less, preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 15 mol% or less.
• Bis(isocyanatomethyl)cyclohexane can be used alone or in combination of two or more types.
• the content of bis(isocyanatomethyl)cyclohexane is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 99% by mass or more, and even more preferably 100% by mass, relative to the polyisocyanate component.
• the polyisocyanate component optionally contains other polyisocyanates.
• polyisocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates (excluding bis(isocyanatomethyl)cyclohexane), aromatic polyisocyanates, and araliphatic polyisocyanates.
• aliphatic polyisocyanates include aliphatic diisocyanates.
• aliphatic diisocyanates include 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.
• alicyclic polyisocyanates include alicyclic diisocyanates, such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,4'-, 2,4'-, or 2,2'-methylene bis(cyclohexyl isocyanate) or a mixture thereof (H 12 MDI), 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.
• alicyclic diisocyanates such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 4,
• aromatic polyisocyanates include aromatic diisocyanates.
• aromatic diisocyanates include 4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate or mixtures thereof (MDI), 2,4- or 2,6-tolylene diisocyanate or mixtures thereof (TDI), o-tolidine diisocyanate, 1,5-naphthalene diisocyanate (NDI), m- or p-phenylene diisocyanate or mixtures thereof, 4,4'-diphenyl diisocyanate, and 4,4'-diphenyl ether diisocyanate.
• MDI 4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate or mixtures thereof
• TDI 2,4- or 2,6-tolylene diisocyanate or mixtures thereof
• NDI 1,5-naphthalene diisocyanate
• araliphatic polyisocyanates examples include araliphatic diisocyanates.
• 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 ⁇ , ⁇ '-diisocyanato-1,4-diethylbenzene.
• the content of the other polyisocyanate is, for example, 20% by mass or less, preferably 10% by mass or less, and, for example, 1% by mass or more, relative to the polyisocyanate component.
• polyisocyanates can be used alone or in combination of two or more types.
• the polyisocyanate component preferably does not contain other polyisocyanates and consists of bis(isocyanatomethyl)cyclohexane.
• the polyol component includes a high molecular weight polyol and a low molecular weight polyol.
• the high molecular weight polyol is a macropolyol, which is a compound having two or more hydroxyl groups.
• the number average molecular weight of the high molecular weight polyol is, for example, 400 or more, preferably 500 or more, from the viewpoint of reducing the viscosity of the isocyanate-terminated prepolymer and improving the handleability, more preferably 1200 or more, even more preferably 1400 or more, particularly preferably 1800 or more, and, for example, 10000 or less, preferably 5000 or less, from the viewpoint of improving transparency, more preferably 3200 or less, even more preferably 2500 or less.
• the number average molecular weight can be determined as a polystyrene equivalent molecular weight by known gel permeation chromatography (hereinafter the same).
• high molecular weight polyols examples include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and polymer polyols.
• Preferred examples of high molecular weight polyols include polyether polyols and polyester polyols.
• polyether polyols examples include polyoxy (C2-3) alkylene polyols and polytetramethylene ether polyols.
• Polyoxy (C2-3) alkylene polyol is, for example, an addition polymer of alkylene oxide having 2-3 carbon atoms using a low molecular weight polyol described below or a known polyamine compound as an initiator.
• alkylene oxides examples include propylene oxide and ethylene oxide. These alkylene oxides can be used alone or in combination of two or more types.
• Polyoxyalkylene polyols include, for example, random and/or block copolymers of propylene oxide and ethylene oxide.
• polyoxy (C2-3) alkylene polyols include polyoxyethylene polyols, polyoxypropylene polyols, and polyoxyethylene polyoxypropylene copolymers.
• polytetramethylene ether polyol is polytetramethylene ether glycol.
• polytetramethylene ether glycol include ring-opening polymers (crystalline polytetramethylene ether glycol) obtained by cationic polymerization of tetrahydrofuran, and amorphous (non-crystalline) polytetramethylene ether glycols in which polymerization units such as tetrahydrofuran are copolymerized with alkyl-substituted tetrahydrofuran and a dihydric alcohol, which will be described later.
• amorphous (non-crystalline) refers to a liquid state at room temperature (25°C).
• polytetramethylene ether polyol preferably, polytetramethylene ether polyol is used.
• polyether polyol more preferably, polytetramethylene ether glycol is used.
• polyester polyols include condensed polyester polyols and ring-opened polyester polyols.
• condensed polyester polyols include adipate-based polyester polyols and phthalic acid-based polyester polyols.
• ring-opened polyester polyols include lactone-based polyester polyols, more specifically, polycaprolactone polyols.
• polyester polyol preferably, a ring-opened polyester polyol is used.
• polyester polyol more preferably, a polycaprolactone polyol is used.
• a polyether polyol is more preferred.
• the high molecular weight polyol is more preferably made of a polyether polyol.
• High molecular weight polyols can be used alone or in combination of two or more types.
• the hydroxyl value of the high molecular weight polyol is, for example, 30 mgKOH/g or more, preferably 50 mgKOH/g or more, and, for example, 200 mgKOH/g or less, preferably 150 mgKOH/g or less, more preferably 100 mgKOH/g or less, and even more preferably 80 mgKOH/g or less.
• the content of the high molecular weight polyol is, for example, 90.00% by mass or more, preferably 95.00% by mass or more, more preferably 98.00% by mass or more, even more preferably 99.00% by mass or more, and for example, 99.95% by mass or less, preferably 99.90% by mass or less, based on the polyol component.
• the low-molecular-weight polyol is a compound having two or more hydroxyl groups and has a number average molecular weight of, for example, less than 400, preferably 300 or less.
• Low molecular weight polyols contain 1,4-butanediol as an essential component.
• the content of 1,4-butanediol relative to the low molecular weight polyol is, for example, 80% by mass or more, preferably 90% by mass or more, more preferably 99% by mass or more, and even more preferably 100% by mass.
• the low molecular weight polyol optionally contains other low molecular weight polyols.
• low molecular weight polyols include, for example, dihydric alcohols (excluding 1,4-butanediol), trihydric alcohols, and tetrahydric or higher alcohols.
• Dihydric alcohols include linear dihydric alcohols and branched dihydric alcohols.
• linear dihydric alcohols examples include linear dihydric alcohols having 2 to 6 carbon atoms.
• linear dihydric alcohols having 2 to 6 carbon atoms include ethylene glycol, 1,3-propanediol, 1,5-pentanediol, and 1,6-hexanediol.
• branched dihydric alcohols include branched dihydric alcohols having 3 to 6 carbon atoms.
• branched dihydric alcohols having 3 to 6 carbon atoms include 1,2-propanediol, 1,3-butanediol, 1,2-butanediol, neopentyl glycol, and 3-methyl-1,5-pentanediol.
• Trihydric alcohols include, for example, glycerin and trimethylolpropane.
• tetrahydric or higher alcohols examples include pentaerythritol and diglycerin.
• the content of the other low molecular weight polyol is, for example, 20% by mass or less, preferably 10% by mass or less, and for example, 1% by mass or more, relative to the low molecular weight polyol.
• Low molecular weight polyols can be used alone or in combination of two or more types.
• the low molecular weight polyol preferably does not contain other low molecular weight polyols and consists of 1,4-butanediol.
• the content of the low molecular weight polyol is, for example, 0.05% by mass or more, preferably 0.10% by mass or more, and, for example, 10.00% by mass or less, preferably 5.00% by mass or less, more preferably 2.00% by mass or less, and even more preferably 1.00% by mass or less, relative to the polyol component.
• the content of the low molecular weight polyol is, for example, 0.05 parts by mass or more, more preferably 0.10 parts by mass or more, even more preferably 0.15 parts by mass or more, and for example, 1.50 parts by mass or less, preferably 1.00 parts by mass or less, more preferably 0.50 parts by mass or less, even more preferably 0.30 parts by mass or less, and particularly preferably 0.20 parts by mass or less, per 100 parts by mass of the high molecular weight polyol.
• the content of the low molecular weight polyol is equal to or less than the above upper limit, the viscosity of the isocyanate-terminated prepolymer can be reduced, improving the ease of handling.
• the isocyanate-terminated prepolymer is obtained by reacting a polyisocyanate component with a polyol component, as described in detail below.
• the curing agent is a compound containing two or more active hydrogen groups (e.g., a hydroxyl group and an amino group), and examples thereof include a hydroxyl group-containing compound and a polyamine.
• Hydroxyl-containing compounds include, for example, 1,4-butanediol and other low molecular weight polyols mentioned above.
• the other low molecular weight polyol is a trihydric alcohol. More preferably, the other low molecular weight polyol is trimethylolpropane.
• Polyamines include, for example, aliphatic diamines, alicyclic diamines, aromatic diamines and other diamines.
• Aliphatic diamines include, for example, ethylenediamine, 1,3-propanediamine, 1,3- or 1,4-butanediamine, and 1,6-hexamethylenediamine.
• alicyclic diamines examples include 1,4-cyclohexanediamine, 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine), 4,4'-dicyclohexylmethanediamine, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane, and 1,3-bis(aminomethyl)cyclohexane.
• Aromatic diamines include, for example, o-, m-, or p-tolylenediamine (TDA, OTD), 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), 3,5-bis(methylthio)-2,6-toluenediamine, and 3,5-bis(methylthio)-2,4-toluenediamine.
• TDA o-, m-, or p-tolylenediamine
• MOCA 3,3'-dichloro-4,4'-diaminodiphenylmethane
• 3,5-bis(methylthio)-2,6-toluenediamine 3,5-bis(methylthio)-2,4-toluenediamine.
• diamines include, for example, hydrazine.
• the hardener is preferably a hydroxyl group-containing compound.
• the curing agent more preferably contains 1,4-butanediol.
• the content of 1,4-butanediol relative to the curing agent 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 100% by mass.
• the curing agent may contain the other low molecular weight polyols listed above in addition to 1,4-butanediol.
• the curing agent contains other low molecular weight polyols, transparency can be improved.
• the content of the other low molecular weight polyol is, for example, 20% by mass or less, preferably 10% by mass or less, and, for example, 1% by mass or more, preferably 5% by mass or more, relative to the curing agent.
• the transparency can be improved, but when the curing agent contains other low molecular weight polyols, the mechanical strength tends to decrease.
• the curing agent contains 1,4-butanediol and other low molecular weight polyols, and from the viewpoint of mechanical strength, the curing agent does not contain other low molecular weight polyols and consists of 1,4-butanediol.
• the polyol component of the isocyanate-terminated prepolymer preferably contains 1,4-butanediol as the low molecular weight polyol, and the curing agent contains 1,4-butanediol.
• both the low molecular weight polyol as the polyol component of the isocyanate-terminated prepolymer and the curing agent contain 1,4-butanediol. This further improves transparency.
• the method for producing a polyurethane elastomer is a prepolymer method, and includes a first step of reacting a polyisocyanate component with a polyol component to produce an isocyanate-terminated prepolymer, and a second step of reacting the isocyanate-terminated prepolymer with a curing agent to produce a polyurethane elastomer.
• the mixing ratio of the polyisocyanate component and the polyol component is adjusted so that there is an excess of isocyanate groups relative to hydroxyl groups. More specifically, the equivalent ratio of the isocyanate groups in the polyisocyanate component to the hydroxyl groups in the polyol component (isocyanate groups/hydroxyl groups) is, for example, 1.5 or more, preferably 1.8 or more, more preferably 2 or more, even more preferably 2.5 or more, and for example, 10 or less.
• Polymerization methods include, for example, bulk polymerization and solution polymerization.
• the polymerization method is preferably bulk polymerization.
• the polyisocyanate component and the polyol component are reacted under a nitrogen stream.
• the reaction temperature is preferably lower than the reaction temperature in the second step described below (the reaction temperature in the reaction of the isocyanate-terminated prepolymer and the curing agent), and is, for example, 50°C or higher, preferably 70°C or higher, and, for example, 100°C or lower.
• the reaction time is, for example, 0.5 hours or more, preferably 1 hour or more, and, for example, 15 hours or less.
• a known urethane catalyst e.g., amines and organometallic compounds (dibutyltin dilaurate)
• a known urethane catalyst e.g., amines and organometallic compounds (dibutyltin dilaurate)
• a known urethane catalyst can be added in an appropriate ratio, if necessary.
• the ratio of the urethane catalyst added is set appropriately depending on the purpose and application.
• additives e.g., antioxidants, heat stabilizers, antifoaming agents
• additives can be added in appropriate proportions, if necessary.
• the isocyanate group concentration of the reaction mixture containing the isocyanate-terminated prepolymer is, for example, 1% by mass or more, preferably 3% by mass or more, and, for example, 30% by mass or less, preferably 10% by mass or less, more preferably 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.
• the reaction mixture may contain unreacted polyisocyanate components (isocyanate monomers) in addition to the isocyanate-terminated prepolymer.
• the unreacted polyisocyanate components are removed from the reaction mixture by a known removal method, as necessary. Examples of the removal method include distillation and extraction.
• the isocyanate-terminated prepolymer (the reaction mixture containing the isocyanate-terminated prepolymer) and a curing agent are reacted to produce a polyurethane elastomer.
• reaction mixture containing the isocyanate-terminated prepolymer reaction mixture containing the isocyanate-terminated prepolymer
• reaction mixture containing the isocyanate-terminated prepolymer reaction mixture containing the isocyanate-terminated prepolymer
• vacuum degas the mixture as necessary to prepare a mixture of the isocyanate-terminated prepolymer and the curing agent.
• the mixing ratio of the isocyanate-terminated prepolymer and the curing agent is, for example, an equivalent ratio (isocyanate group/hydroxyl group) of the isocyanate groups in the isocyanate-terminated prepolymer to the hydroxyl groups of the curing agent (low molecular weight polyol), which is, for example, 0.75 or more, preferably 0.9 or more, for example, 1.3 or less, preferably 1.2 or less.
• the mixing temperature is, for example, 50°C or higher, preferably 70°C or higher, and, for example, 100°C or lower.
• the mixture of isocyanate-terminated prepolymer and curing agent is then cured (reacted) in a preheated mold and demolded. This results in a polyurethane elastomer molded into the desired shape.
• the reaction temperature is preferably higher than the reaction temperature of the reaction of the polyisocyanate component and the polyol component in the first step described above, for example, more than 100°C, preferably 105°C or higher, and for example, 200°C or lower, preferably 150°C or lower, more preferably 120°C or lower.
• the reaction time is, for example, 0.5 hours or more, preferably 1 hour or more, and, for example, 15 hours or less.
• the polyurethane elastomer can be aged.
• the aging temperature is, for example, 10°C or more, preferably 20°C or more, and for example, 50°C or less, preferably 40°C or less.
• the aging time is, for example, 1 hour or more, preferably 10 hours or more, and for example, 20 days or less, preferably 10 days or less.
• the polyurethane elastomer may contain known additives in addition to the reaction product of the isocyanate-terminated prepolymer and the curing agent, if necessary.
• the polyurethane elastomer may be a polyurethane elastomer composition.
• Additives include, for example, antioxidants, heat stabilizers, UV absorbers, light stabilizers, antiblocking agents, release agents, pigments, dyes, lubricants, fillers, hydrolysis inhibitors, rust inhibitors, and bluing agents.
• antioxidants heat stabilizers, UV absorbers, light stabilizers, antiblocking agents, release agents, pigments, dyes, lubricants, fillers, hydrolysis inhibitors, rust inhibitors, and bluing agents.
• the amount and timing of additives to be added are appropriately determined depending on the purpose and application.
• the urethane group concentration of the polyurethane elastomer is, for example, 1.3 mmol/g or more, preferably 1.6 mmol/g or more, more preferably 1.8 mmol/g or more, and for example, 2.5 mmol/g or less, preferably 2.0 mmol/g or less.
• the mechanical strength can be improved.
• the urethane group concentration of the polyurethane elastomer is equal to or lower than the above upper limit, transparency can be improved.
• the urethane group concentration of a polyurethane elastomer is an index of the hard segments in the polyurethane elastomer, and as the urethane group concentration of a polyurethane elastomer increases, the mechanical strength tends to improve but the transparency tends to decrease. On the other hand, as the urethane group concentration of a polyurethane elastomer decreases, the transparency tends to improve but the mechanical strength tends to improve. In other words, there is a trade-off between transparency and mechanical strength.
• the urethane group concentration can be measured according to the examples described below.
• the haze of the polyurethane elastomer is, for example, 80% or less, preferably 60% or less, and more preferably 40% or less.
• the polyurethane elastomer is manufactured as a TPU (thermoplastic polyurethane resin) or a TSU (thermosetting polyurethane resin).
• the polyurethane elastomer is manufactured as a TSU (thermosetting polyurethane resin).
• the polyurethane elastomer is molded by a known molding method.
• molding methods include cast molding, thermocompression molding, injection molding, extrusion molding, and spinning molding.
• shapes after molding include plate-like, fiber-like, strand-like, film-like, sheet-like, pipe-like, bottle-like, hollow, box-like, and button-like shapes.
• the preferred molding method is cast molding. Therefore, the polyurethane elastomer is preferably a cast polyurethane elastomer.
• a cast polyurethane elastomer is a molded product (cast molded product) obtained by cast molding, and is an article that independently has a predetermined shape according to the purpose and use, and is distinguished from a coating agent that is applied to a substrate.
• an isocyanate-terminated prepolymer and a curing agent are preferably mixed together to prepare a mixture.
• the mixture is then degassed as necessary and fed into a preheated mold.
• the mixture is heated and cured within the mold. This results in a polyurethane elastomer (molded product) molded into the desired shape.
• molded products include, for example, transparent hard plastics, coating materials, adhesives, adhesives, waterproofing materials, potting agents, inks, binders, films, sheets, bands, belts, tubes, blades, speakers, sensors, outsoles, threads, fibers, nonwoven fabrics, cosmetics, footwear, heat insulation materials, sealing materials, tape materials, sealing materials, solar power generation materials, robot materials, android materials, wearable materials, clothing products, sanitary products, cosmetics, furniture products, food packaging materials, sporting goods, leisure goods, medical supplies, nursing care products, housing materials, acoustic materials, lighting materials, vibration-proofing materials, soundproofing materials, daily necessities, miscellaneous goods, cushions, bedding, stress absorbing materials, stress relaxation materials, automotive interior materials, automotive exterior materials, railway materials, aircraft materials, optical materials, office equipment materials, miscellaneous goods surface protection materials, semiconductor sealing materials, self-repairing materials, health equipment, eyeglass lenses, toys, packing, cable sheaths, wire harnesses, telecommunications cables, automotive wiring, computer wiring, industrial
• the polyurethane elastomer contains a reaction product of an isocyanate-terminated prepolymer and a curing agent.
• the polyol component of the isocyanate-terminated prepolymer contains a low molecular weight polyol, and the low molecular weight polyol contains 1,4-butanediol. Therefore, transparency can be improved.
• the method for producing a polyurethane elastomer comprises a first step of reacting a polyisocyanate component with a polyol component to produce an isocyanate-terminated prepolymer, and a second step of reacting an isocyanate-terminated prepolymer with a curing agent to produce a polyurethane elastomer.
• the polyol component also contains a low molecular weight polyol that includes 1,4-butanediol. This improves transparency.
• 1,4-H 6 XDI 1,4-bis(isocyanatomethyl)cyclohexane, trade name: Fortimo 1,4H 6 XD, content of trans-1,4-bis(isocyanatomethyl)cyclohexane: 86 mol %, content of cis-1,4-bis(isocyanatomethyl)cyclohexane: 14 mol %
• 4,4'-MDI 4,4'-diphenylmethane diisocyanate
• trade name: Cosmonate PH manufactured by Mitsui Chemicals, Inc.
• PTMEG#2000 number average molecular weight 2000
• polytetramethylene ether glycol trade name: PTMG2000
• hydroxyl value 56.1 mgKOH/g
• PTMEG#1400 number average molecular weight 1400
• polytetramethylene ether glycol trade name: PTG1400SN
• hydroxyl value 80.1 mg KOH/g, Hodogaya Chemical Co., Ltd.
• Example 1 [First step] According to the recipe shown in Table 1, the polyisocyanate component and the polyol component were charged into a four-neck flask equipped with a reflux condenser, a nitrogen inlet tube, a thermometer, and a stirrer. Then, 0.15 parts by mass of Irganox 245, 0.1 parts by mass of JPP100, and 0.2 parts by mass of BYK-088 were added. Then, dibutyltin dilaurate, which had been diluted to 2% by mass with diisononyl adipate in advance, was added so that the catalyst amount was 5 ppm. The polyisocyanate component and the polyol component were reacted at 80° C. under a nitrogen atmosphere to obtain a reaction mixture containing an isocyanate-terminated prepolymer.
• Examples 2 to 9 and Comparative Examples 1 to 4 A polyurethane elastomer in a sheet shape was produced in the same manner as in Example 1, except that the compounding recipe of each component was changed according to Table 1. In Table 1, the numerical values of each component are parts by mass.
• Viscosity of reaction mixture containing isocyanate-terminated prepolymer The viscosity of the reaction mixture containing the isocyanate-terminated prepolymer of each Example and Comparative Example was measured. Specifically, the viscosity was measured at a temperature of 80° C., a 40P plate, and a rotation speed of 188 rpm by a cone-plate viscometer method in accordance with JIS K 5600-2-3 (2014). The results are shown in Table 1.
• the polyurethane elastomer and the method for producing the polyurethane elastomer of the present invention can be suitably used for the production of, for example, transparent hard plastics, coating materials, pressure sensitive adhesives, adhesives, waterproof materials, potting agents, inks, binders, films, sheets, bands, belts, tubes, blades, speakers, sensors, outsoles, threads, fibers, nonwoven fabrics, cosmetics, shoe products, heat insulating materials, sealing materials, tape materials, sealing materials, solar power generation members, robot members, android members, wearable members, clothing products, sanitary products, cosmetic products, furniture products, food packaging members, sporting goods, leisure goods, medical supplies, nursing care products, housing members, acoustic members, lighting members, vibration-proof members, soundproofing members, daily necessities, miscellaneous goods, cushions, bedding, stress absorbing materials, stress relaxation materials, automobile interior materials, automobile exterior materials, railway members, aircraft members, optical members, office automation equipment members, miscellaneous surface protection members, semiconductor sealing materials, self-repairing materials

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• Polyurethanes Or Polyureas (AREA)

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• 2024
  • 2024-08-01 JP JP2025539350A patent/JPWO2025033312A1/ja active Pending
  • 2024-08-01 WO PCT/JP2024/027506 patent/WO2025033312A1/ja active Pending
  • 2024-08-01 CN CN202480024452.5A patent/CN120936645A/zh active Pending

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