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
  • C08G18/08—Processes
• • 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
  • C08G18/08—Processes
  • C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• • 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
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/30—Low-molecular-weight compounds
• • 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
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/48—Polyethers
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06N—WALL, FLOOR, OR LIKE COVERING MATERIALS, e.g. LINOLEUM, OILCLOTH, ARTIFICIAL LEATHER, ROOFING FELT, CONSISTING OF A FIBROUS WEB COATED WITH A LAYER OF MACROMOLECULAR MATERIAL; FLEXIBLE SHEET MATERIAL NOT OTHERWISE PROVIDED FOR
  • D06N3/00—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof
  • D06N3/12—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins
  • D06N3/14—Artificial leather, oilcloth or other material obtained by covering fibrous webs with macromolecular material, e.g. resins, rubber or derivatives thereof with macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. gelatine proteins with polyurethanes

Definitions

• the present invention relates to a moisture-curable polyurethane hot melt resin composition, an adhesive, and synthetic leather.
• Synthetic leather uses polyurethane (PU), polyvinyl chloride (PVC), olefin-based thermoplastic elastomer (TPO), etc. as the surface material, and these surface materials are generally bonded to a base fabric such as cloth or nonwoven fabric with an adhesive (see, for example, Patent Document 1).
• solvent-based adhesives have been the most widespread and commonly used up until now, but as part of environmental efforts, regions, countries, and companies are calling for a reduction in VOCs, and it is becoming necessary to replace solvent-based with water-based or solvent-free adhesives.
• the problem that the present invention aims to solve is to provide a moisture-curable polyurethane hot melt resin composition that has excellent adhesion, low-temperature flexibility, and flame retardancy.
• the present invention provides a moisture-curable polyurethane hot-melt resin composition containing a hot-melt urethane prepolymer (A) having an isocyanate group and a flame retardant (B), characterized in that the hot-melt prepolymer (A) is made from a polyol (a) containing 50 mass% or more of a polyether polyol (a1), and the content of the flame retardant (B) is more than 15 mass parts per 100 mass parts of the hot-melt urethane prepolymer (A).
• the present invention also provides an adhesive that contains the moisture-curable polyurethane hot melt resin composition.
• the present invention also provides synthetic leather that has at least a thermoplastic resin layer and the adhesive layer.
• the moisture-curable polyurethane hot melt resin composition of the present invention has excellent adhesion, low-temperature flexibility, and flame retardancy. Therefore, the moisture-curable polyurethane hot melt resin composition of the present invention can be particularly suitably used in the manufacture of synthetic leather that uses a thermoplastic resin as the skin material.
• the moisture-curable polyurethane hot melt resin composition of the present invention contains a hot melt urethane prepolymer (A) having an isocyanate group, which is made from a specific polyol (a), and a specific amount of a flame retardant (B).
• A hot melt urethane prepolymer having an isocyanate group, which is made from a specific polyol (a), and a specific amount of a flame retardant (B).
• the hot melt urethane prepolymer (A) having isocyanate groups is made from polyol (a) containing 50% by mass or more of polyether polyol (a1).
• the amount of polyether polyol (a1) used is preferably 50 to 90% by mass, and more preferably 55 to 70% by mass, of the polyol (a) in order to obtain even better low-temperature flexibility.
• polyether polyol (a1) for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxyethylene polyoxypropylene glycol, polyoxyethylene polyoxytetramethylene glycol, polyoxypropylene polyoxytetramethylene glycol, etc. can be used. These polyols may be used alone or in combination of two or more. Among these, polypropylene glycol and/or polytetramethylene glycol are preferred because they provide even better low-temperature flexibility, and polytetramethylene glycol is more preferred because they provide even better heat resistance and wet heat resistance.
• the polyether polyol may be derived from a plant.
• plant-derived polyether polyol for example, "Bio PTMG” manufactured by Mitsubishi Chemical Corporation, “Bio PTG” manufactured by Hodogaya Chemical Co., Ltd., biomass polypropylene glycol manufactured by Vithal Castor Polyols, etc. can be obtained as commercially available products.
• polyol (a) other polyols can be used in combination with the polyether polyol (a).
• other polyols for example, commercially available polyols such as polyester polyols, polycarbonate polyols, polybutadiene polyols, silicone diols, and acrylic diols can be used. These polyols may be used alone or in combination of two or more, and may be derived from petroleum or plants.
• polyester polyols are preferred because they provide even better adhesion.
• the number average molecular weight of the polyol (a) is preferably 500 to 10,000, and more preferably 1,000 to 6,000, in order to obtain even better adhesion, low-temperature flexibility, and mechanical strength.
• the number average molecular weight of the polyol (a) is a value measured by gel permeation chromatography (GPC).
• the hot melt urethane prepolymer (A) having an isocyanate group can be, for example, a reaction product of the polyol (a) and the polyisocyanate (b).
• polyisocyanate (b) for example, aromatic polyisocyanates such as polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate isocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate; aliphatic or alicyclic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate can be used.
• aromatic polyisocyanates such as polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphen
• polyisocyanates may be used alone or in combination of two or more, and may be derived from petroleum or plants.
• aromatic polyisocyanates are preferred, and diphenylmethane diisocyanate is more preferred, in that they provide even better reactivity and adhesion.
• the hot melt urethane prepolymer (A) has isocyanate groups at the polymer terminals or within the molecule that can react with moisture present in the air or in the substrate or adherend to which the urethane prepolymer is applied to form a crosslinked structure.
• the hot melt urethane prepolymer (A) can be produced, for example, by dropping the polyol (a) into a reaction vessel containing the polyisocyanate (b), heating the vessel, and reacting the polyisocyanate (b) under conditions in which the isocyanate groups of the polyisocyanate (b) are in excess of the hydroxyl groups of the polyol (a).
• the molar ratio [NCO/OH] of the hydroxyl groups in the polyol (a) to the isocyanate groups in the polyisocyanate (b) is preferably 1.3 to 2.5, and more preferably 1.5 to 2.0, in order to obtain even better hot melt properties, adhesive properties, and low-temperature flexibility.
• the isocyanate group content (hereinafter abbreviated as "NCO%) of the hot melt urethane prepolymer (A) is preferably 1.2 to 5.0 mass%, more preferably 1.7 to 3.5 mass%, in order to obtain even better hot melt properties, adhesion, and low-temperature flexibility.
• the NCO% of the hot melt urethane prepolymer (A) is a value measured by potentiometric titration in accordance with JIS K1603-1:2007.
• the flame retardant (B) is an essential component for obtaining excellent flame retardancy, and its content must exceed 15 parts by mass per 100 parts by mass of the hot-melt urethane prepolymer (A).
• the content of the flame retardant (B) is preferably 17.5 to 55 parts by mass per 100 parts by mass of the hot-melt urethane prepolymer (A) in order to maintain a high level of low-temperature flexibility and adhesion and obtain even better flame retardancy.
• the flame retardant (B) may be, for example, a phosphate ester, a phosphate-containing flame retardant, red phosphorus, a bromine-containing flame retardant, a boron-containing flame retardant, an antimony-containing flame retardant, a metal hydroxide, graphite, a phosphorus-boron compound, a vinyl polymer, or the like.
• These flame retardants may be used alone or in combination of two or more.
• a phosphate ester having three or more aromatic rings is preferred, and a phosphate ester having four or more aromatic rings is more preferred, in that it maintains a high level of low-temperature flexibility and adhesion, and provides even more excellent flame retardancy.
• the moisture-curable polyurethane hot-melt resin composition of the present invention contains the hot-melt urethane prepolymer (A) and the flame retardant (B) as essential components, but may contain other additives as necessary.
• additives examples include urethane catalysts, neutralizing agents, crosslinking agents, silane coupling agents, thickeners, fillers, thixotropic agents, tackifiers, waxes, heat stabilizers, light resistance stabilizers, fluorescent whitening agents, foaming agents, pigments, dyes, conductivity agents, antistatic agents, moisture permeability enhancers, water repellents, oil repellents, hollow foams, water absorbents, moisture absorbents, deodorizers, foam stabilizers, plasticizers, antiblocking agents, hydrolysis inhibitors, etc. These additives may be used alone or in combination of two or more.
• the moisture-curable polyurethane hot melt resin composition of the present invention has excellent adhesion, low-temperature flexibility, and flame retardancy. Therefore, the moisture-curable polyurethane hot melt resin composition of the present invention can be particularly suitably used in the manufacture of synthetic leather that uses a thermoplastic resin as the skin material.
• the synthetic leather has at least a thermoplastic resin layer and an adhesive layer containing the moisture-curable polyurethane hot melt resin composition, and may be, for example, a layer of a substrate, the adhesive layer, and a thermoplastic resin layer laminated in that order.
• the substrate may be, for example, a nonwoven fabric, woven fabric, or knitted fabric made of polyester fiber, polyethylene fiber, nylon fiber, acrylic fiber, polyurethane fiber, acetate fiber, rayon fiber, polylactic acid fiber, cotton, hemp, silk, wool, glass fiber, carbon fiber, or a blend of these fibers.
• the thermoplastic resin layer may be formed from, for example, known polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride, polystyrene, TPO (thermoplastic olefinic elastomer), thermoplastic ester elastomer, thermoplastic polyurethane, etc.
• TPO thermoplastic olefinic elastomer
• thermoplastic ester elastomer thermoplastic polyurethane
• thermoplastic polyurethane etc.
• it has excellent adhesion and low-temperature flexibility, and in particular, for polyvinyl chloride, which is difficult to adhere to, it has excellent adhesion and low-temperature flexibility whether it is foamed or unfoamed.
• the adhesive layer is formed from the moisture-curable polyurethane hot melt resin composition of the present invention, and examples of the method for forming the adhesive layer include a method in which the moisture-curable polyurethane hot melt resin composition is melted at 100 to 140°C, and then coated onto the thermoplastic resin layer or the substrate using a coater method such as a roll coater, spray coater, T-die coater, knife coater, or comma coater; a precision method such as a dispenser, inkjet printing, screen printing, or offset printing; or a nozzle coater, and then the layers are bonded together.
• a coater method such as a roll coater, spray coater, T-die coater, knife coater, or comma coater
• a precision method such as a dispenser, inkjet printing, screen printing, or offset printing
• a nozzle coater a method in which the moisture-curable polyurethane hot melt resin composition is melted at 100 to 140°C, and then coated onto the thermoplastic resin
• the adhesive can be dried and cured as necessary using known methods.
• the synthetic leather may further have a surface treatment layer on top of the thermoplastic resin layer.
• the surface treatment layer may be formed from, for example, a known solvent-based urethane resin, water-based urethane resin, solvent-based acrylic resin, water-based acrylic resin, etc.
• Example 1 A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 171 parts by mass of polytetramethylene glycol (number average molecular weight: 2,000, hereinafter abbreviated as "PEt-1”), 78 parts by mass of polyester polyol (residued by reacting 1,6-hexanediol and orthophthalic acid, number average molecular weight: 2,000, hereinafter abbreviated as "PEs-1”), and 62 parts by mass of polyester polyol (residued by reacting 1,6-hexanediol and sebacic acid, number average molecular weight: 3,500, hereinafter abbreviated as "PEs-2”), mixed, and heated at 100°C under reduced pressure to dehydrate the water in the flask until the water content was 0.05% by mass or less.
• PEt-1 polytetramethylene glycol
• PET
• MDI 4,4'-diphenylmethane diisocyanate
• Example 2 In a four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser, 74 parts by mass of PEt-1, 31 parts by mass of PEs-1, and 18 parts by mass of PEs-2 were added, mixed, and heated under reduced pressure at 100 ° C., and the moisture in the flask was dehydrated until it was 0.05% by mass or less. Next, the flask was cooled to 90 ° C., 27 parts by mass of MDI melted at 70 ° C. was added, and the mixture was reacted at 110 ° C.
• Example 3 In a four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser, 48 parts by mass of polypropylene glycol (number average molecular weight: 2,000, hereinafter abbreviated as "PEt-2”), 17 parts by mass of PEs-1, and 22 parts by mass of polyester polyol (ethylene glycol, neopentyl glycol, 16-hexanediol, and adipic acid reacted, number average molecular weight: 5,500, hereinafter abbreviated as "PEs-3”) were placed, mixed, and heated under reduced pressure at 100 ° C.
• PEt-2 polypropylene glycol
• polyester polyol ethylene glycol, neopentyl glycol, 16-hexanediol, and adipic acid reacted, number average molecular weight: 5,500
• Example 4 A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 133 parts by mass of PEt-1, 56 parts by mass of PEs-1, and 33 parts by mass of PEs-2, mixed, and heated under reduced pressure at 100 ° C. to dehydrate the water content in the flask to 0.05% by mass or less. Next, the flask was cooled to 90 ° C., 49 parts by mass of MDI melted at 70 ° C. was added, and the mixture was reacted at 110 ° C. for about 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, to obtain a hot melt urethane prepolymer. 30 parts by mass of flame retardant (B1) was blended with 100 parts by mass of this hot melt urethane prepolymer to obtain a moisture-curable polyurethane hot melt resin composition (4).
• B1 flame retardant
• Example 5 A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 139 parts by mass of PEt-2, 32 parts by mass of PEs-1, and 43 parts by mass of PEs-3, mixed, and heated under reduced pressure at 100 ° C. to dehydrate the water content in the flask to 0.05% by mass or less. Next, the flask was cooled to 90 ° C., 47 parts by mass of MDI melted at 70 ° C. was added, and the mixture was reacted at 110 ° C. for about 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, to obtain a hot melt urethane prepolymer. 35 parts by mass of flame retardant (B1) was blended with 100 parts by mass of this hot melt urethane prepolymer to obtain a moisture-curable polyurethane hot melt resin composition (5).
• Example 6 In a four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser, 83 parts by mass of PEt-1, 19 parts by mass of PEs-1, and 26 parts by mass of PEs-3 were added, mixed, and heated under reduced pressure at 100 ° C. to dehydrate the water content in the flask to 0.05% by mass or less. Next, the flask was cooled to 90 ° C., 26 parts by mass of MDI melted at 70 ° C. was added, and the mixture was reacted at 110 ° C. for about 3 hours under a nitrogen atmosphere until the isocyanate group content became constant, to obtain a hot melt urethane prepolymer. 40 parts by mass of flame retardant (B1) was blended with 100 parts by mass of this hot melt urethane prepolymer to obtain a moisture-curable polyurethane hot melt resin composition (6).
• B1 flame retardant
• Example 7 A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet and a reflux condenser was charged with 121 parts by mass of PEt-1, 121 parts by mass of PEt-2, 81 parts by mass of PEs-1, and 81 parts by mass of PEs-2, mixed, and heated under reduced pressure at 100 ° C. to dehydrate the water content in the flask to 0.05% by mass or less. Next, the flask was cooled to 90 ° C., 87 parts by mass of MDI melted at 70 ° C. was added, and the mixture was reacted at 110 ° C.
• Example 8 A moisture-curable polyurethane hot melt resin composition (8) was obtained in the same manner as in Example 1, except that PEt-1 was replaced with biomass polytetramethylene glycol ("Bio PTMG” manufactured by Mitsubishi Chemical Corporation, number average molecular weight: 2,000).
• the number average molecular weights of the polyols used in the examples and comparative examples are values measured by gel permeation column chromatography (GPC) under the following conditions.
• Measurement device High-speed GPC device ("HLC-8220GPC” manufactured by Tosoh Corporation) Column: The following columns manufactured by Tosoh Corporation were used, connected in series. "TSKgel G5000” (7.8mm I.D. x 30cm) x 1 "TSKgel G4000” (7.8mm I.D. x 30cm) x 1 "TSKgel G3000” (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mm I.D.
• Test pieces that did not ignite or self-extinguished before the A-marked line, those that self-extinguished within a burning distance of 51 mm (and within 60 seconds), and those with a burning rate of 102 mm/min or less were marked as " ⁇ ", and those that did not were marked as " ⁇ ".
• Examples 1 to 8 which are moisture-curable polyurethane hot melt resin compositions of the present invention, have excellent adhesion, low-temperature flexibility, and flame retardancy.
• Comparative Example 2 is an embodiment in which flame retardant (B) is not used, but the flame retardancy was poor.
• Comparative examples 3 and 4 are examples in which the amount of polyether polyol (a1) used is below the range specified in the present invention, but the low-temperature flexibility and other properties were poor.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Polyurethanes Or Polyureas (AREA)

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• 2023
  • 2023-05-25 CN CN202380061768.7A patent/CN119677791A/zh active Pending
  • 2023-05-25 WO PCT/JP2023/019460 patent/WO2024084729A1/ja not_active Ceased
  • 2023-05-25 JP JP2024536474A patent/JP7718596B2/ja active Active

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