JP7192353B2 - Urethane resin composition, film, and synthetic leather - Google Patents

Description

The present invention relates to a urethane resin composition.

Urethane resins are widely used in various fields such as synthetic leather and molding sheets. However, in particular, when it is used for members that are used for a long period of time, such as synthetic leather for vehicle interior materials, higher durability is required.

There are a wide variety of evaluation items for the durability, including heat resistance, heat and humidity resistance, light resistance, chemical resistance, and wear resistance. are required to have chemical resistance such as oleic acid resistance and sun oil resistance. As a material having excellent oleic acid resistance, for example, a resin composition composed of a polycarbonate-based polyurethane resin, a polyether-based polyurethane resin, and an acrylic resin has been disclosed (see, for example, Patent Document 1).

However, as a material for synthetic leather, not only the above-mentioned oleic acid resistance, but also the required level of flexibility at low temperature is increasing assuming use in cold regions, and furthermore, in order to obtain excellent abrasion resistance There is also a need for superior mechanical strength of However, a material having all these properties has not yet been found.

JP 2012-1693 A

The problem to be solved by the present invention is to provide a urethane resin composition that is excellent in oleic acid resistance, low-temperature flexibility, and mechanical strength.

The present invention provides a polyol (X) containing 1 to 50% by mass of a polycarbonate polyol (A) starting from a glycol having 8 to 11 carbon atoms, a chain extender (Y) having an amino group, and a polyisocyanate ( The present invention provides a urethane resin composition characterized by containing a urethane resin having Z) as an essential raw material.

The present invention also provides a film characterized by being formed from the urethane resin composition, and a synthetic leather characterized by having the film.

The urethane resin composition of the present invention is excellent in oleic acid resistance, low-temperature flexibility, and mechanical strength.

Therefore, the urethane resin composition of the present invention can be suitably used as a material for manufacturing synthetic leather, clothing, support pads, polishing pads, etc., and can be particularly suitably used as a material for synthetic leather. can.

The urethane resin composition of the present invention comprises a polyol (X) containing 1 to 50% by mass of a polycarbonate polyol (A) made from a glycol having 8 to 11 carbon atoms, a chain extender (Y) having an amino group, and a urethane resin containing polyisocyanate (Z) as an essential raw material.

The polycarbonate polyol (A) is an essential component for obtaining particularly excellent low-temperature flexibility. Moreover, the amount of the polycarbonate polyol (A) used must be 1 to 50% by mass in the polyol (X). When the amount of the polycarbonate polyol (A) used in the polyol (X) is less than 1% by mass, the desired low-temperature flexibility cannot be obtained, and when it exceeds 50% by mass, sufficient low-temperature flexibility is obtained. Therefore, oleic acid resistance cannot be obtained. The amount of the polycarbonate polyol (A) used is more preferably in the range of 3 to 40% by mass in the polyol (X) from the viewpoint of sufficiently obtaining even better low-temperature flexibility and resistance to oleic acid.

Examples of the glycol having 8 to 11 carbon atoms as a raw material of the polycarbonate polyol (A) include 2,4-dimethyl-1,5-pentanediol, 2,3-dimethyl-1,5-pentanediol, 2-ethyl-1,5-pentanediol, 2-methyl-1,6-hexanediol, 3-methyl-1,6-hexanediol, 1,7-nonanediol, 2-ethyl-1,6-hexanediol , 2-methyl-1,7-nonanediol, 3-methyl-1,7-nonanediol, 4-methyl-1,7-nonanediol, 1,8-octanediol, 2-methyl-1,8-octane Glycols having 8 to 9 carbon atoms such as diols and 1,9-nonanediol; 2-methyl-1,8-octanediol, 3-methyl-1,8-octanediol, 4-methyl-1,8- Octanediol, 1,10-decanediol, 2-methyl-1,10-decanediol, 3-methyl-1,10-decanediol, 4-methyl-1,10-decanediol, 1,11-undecanediol, etc. and a glycol having 10 to 11 carbon atoms. These glycols may be used alone or in combination of two or more.

As the raw material for the polycarbonate polyol (A), among the above-mentioned, a linear glycol and a glycol having a branched structure are used in combination from the viewpoint of obtaining even more excellent oleic acid resistance, low-temperature flexibility, and mechanical strength. preferably.

When the linear glycol and the glycol having a branched structure are used in combination, the molar ratio [(C8-11 linear chain)/(C8-11 branched chain)] of the two provides even better resistance to oleic acid and low temperature. It is preferably in the range of 10/90 to 90/10, more preferably in the range of 10/90 to 70/30, from the viewpoint of obtaining flexibility and mechanical strength.

Specifically, the polycarbonate diol (A) can be obtained by reacting the above-mentioned glycol having 8 to 11 carbon atoms with carbonate ester and/or phosgene by a known method. In addition, the glycol may be used in combination with a glycol having 2 to 7 carbon atoms, if necessary. The ratio of the glycol having 8 to 11 carbon atoms to be used is preferably 80% by mass or more, more preferably 90% by mass or more, in all the glycols.

As the carbonic acid ester, for example, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, propylene carbonate and the like can be used. These compounds may be used alone or in combination of two or more.

The number average molecular weight of the polycarbonate diol (A) is preferably in the range of 1,500 to 3,500 from the viewpoint of obtaining even better mechanical strength and low-temperature flexibility. In addition, the number average molecular weight of the polycarbonate polyol (A) indicates a value measured by a gel permeation chromatography (GPC) method.

The polyol (X) contains the polycarbonate polyol (A) as an essential component, but may further contain other polyols as necessary.

Examples of other polyols that can be used include polycarbonate polyols other than (A), polyether polyols, polyester polyols, polyacrylic polyols, polybutadiene polyols, and hydrogenated polybutadiene polyols. These polyols may be used alone or in combination of two or more. Among these, it is possible to use a polycarbonate polyol other than the above (A) from the viewpoint that even more excellent oleic acid resistance, low-temperature flexibility, and mechanical strength can be obtained by using it in combination with the polycarbonate polyol (A). preferable.

Polycarbonate polyols other than (A) are not particularly limited as long as they have a carbonate structure. Examples include propanediol, butanediol, pentanediol, hexanediol, 3-methyl-1,5-pentanediol, and neopentyl glycol. It is preferable to use a polycarbonate polyol starting from a glycol having 4 to 6 carbon atoms in order to obtain even more excellent oleic acid resistance, low-temperature flexibility, and mechanical strength. The polycarbonate polyol may be used in combination with other glycol as a glycol component, but the proportion of the glycol having 4 to 6 carbon atoms used is preferably 80% by mass or more in the glycol, and 90% by mass or more. is more preferred.

When a polycarbonate polyol other than the above (A) is used, the amount used is 30 to 95% by mass in the polyol (X) from the viewpoint of obtaining even better oleic acid resistance, low-temperature flexibility, and mechanical strength. A range is preferred, and a range of 55 to 90% by weight is more preferred.

The number average molecular weight of the other polyol is preferably in the range of 600 to 50,000 from the viewpoint of obtaining good mechanical strength of the film, and the other polyol is a polycarbonate polyol other than the above (A) is used, the number average molecular weight is preferably in the range of 1,500 to 3,500 from the viewpoint of obtaining even better oleic acid resistance, low-temperature flexibility, and mechanical strength. In addition, the number average molecular weight of said other polyol shows the value measured by the gel permeation chromatography (GPC) method.

The chain extender (Y) having an amino group is an essential component from the viewpoint of obtaining excellent mechanical strength and resistance to oleic acid.

The chain extender (Y) having an amino group has a number average molecular weight of 50 to 550, and examples thereof include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5- Dimethylpiperazine, isophoronediamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethane Diamines, hydrazines and the like can be used. These chain extenders may be used alone or in combination of two or more. Among these, it is preferable to use a chain extender having an alicyclic structure from the viewpoint of obtaining even more excellent mechanical strength and resistance to oleic acid.

The amount of the chain extender (Y) used is the total amount of the polyol (X), the chain extender (Y), and the polyisocyanate (Z) from the viewpoint of obtaining excellent mechanical strength and resistance to oleic acid. It is preferably in the range of 1 to 15% by mass, more preferably in the range of 3 to 10% by mass.

Examples of the polyisocyanate (Z) include 1,3- and 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2 ,5-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl- 3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1, 5-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2′-diisocyanate, biphenyl-2,4 '-diisocyanate, biphenyl-4,4'-diisocyanate, 3-3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, diphenylmethane-2,4- aromatic polyisocyanate such as diisocyanate; cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di(isocyanatomethyl)cyclohexane, 1,4-di(isocyanatomethyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4-dicyclohexylmethane diisocyanate, 2, 4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate Aliphatic or alicyclic polyisocyanates such as diisocyanate, 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate, and the like can be used. These polyisocyanates may be used alone or in combination of two or more.

The polyisocyanate (Z) preferably contains 10% by mass or more of an aliphatic polyisocyanate from the viewpoint of achieving both excellent low-temperature flexibility and coatability of the urethane resin composition, and 10 to 50% by mass. %, more preferably 13 to 40% by mass. Further, as the polyisocyanate (Z), an aliphatic polyisocyanate and an alicyclic polyisocyanate may be used in combination from the viewpoint of achieving both excellent low-temperature flexibility and coatability of the urethane resin composition. preferable.

The amount of the polyisocyanate (Z) used is 7 to 7 out of the total mass of the polyol (X), the chain extender (Y) and the polyisocyanate (Z), from the viewpoint of obtaining excellent mechanical strength and reactivity. It is preferably in the range of 60 mass %, more preferably in the range of 10 to 45 mass %.

Examples of the method for producing the urethane resin include a method for producing the polyol (X), the chain extender (Y), and the polyisocyanate (Z) at once and reacting them. For example, it is preferably carried out at a temperature of 30 to 100° C. for 3 to 10 hours. Moreover, the reaction may be carried out in a solvent to be described later.

The molar ratio of the hydroxyl group of the polyol (X) and the amino group of the chain extender (Y) to the isocyanate group of the polyisocyanate (Z) [(isocyanate group)/(hydroxyl group and amino group)] is preferably in the range of 0.6 to 2, more preferably in the range of 0.8 to 1.2.

The number average molecular weight of the urethane resin obtained by the above method is preferably in the range of 5,000 to 1,000,000 from the viewpoint of further improving the mechanical strength and flexibility of the film. A range of 000 to 500,000 is more preferred. The number average molecular weight of the urethane resin is the value measured by gel permeation chromatography (GPC).

The urethane resin composition contains the urethane resin as an essential component, but may contain other components as necessary.

Examples of the other components include solvents, pigments, flame retardants, plasticizers, softeners, stabilizers, waxes, antifoaming agents, dispersants, penetrants, surfactants, fillers, antifungal agents, antibacterial agents, Ultraviolet absorbers, antioxidants, weather stabilizers, fluorescent whitening agents, antioxidants, thickeners, and the like can be used. These components may be used alone or in combination of two or more.

Examples of the solvent include water, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, methyl ethyl ketone, methyl-n-propyl ketone, acetone, ketone solvents such as methyl isobutyl ketone; Ester solvents such as methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, isopropyl acetate, isobutyl acetate, isobutyl acetate and sec-butyl acetate; alcohol solvents such as methanol, ethanol, isopropyl alcohol and butanol can be used. . These solvents may be used alone or in combination of two or more.

The content of the solvent is preferably in the range of 30 to 90% by mass in the urethane resin composition from the viewpoint of workability and viscosity.

A film is obtained by applying the urethane resin composition of the present invention to a substrate and drying it.

As the substrate, for example, fibrous substrates such as nonwoven fabrics, woven fabrics, and knitted fabrics; resin films, and the like can be used. Materials constituting the fibrous base material include, for example, chemical fibers such as polyester fiber, nylon fiber, acrylic fiber, polyurethane fiber, acetate fiber, rayon fiber, and polylactic acid fiber; Blended fibers and the like can be used.

As the resin film, for example, a polyethylene terephthalate film, a polycarbonate film, an acrylic resin film, a COP (cycloolefin polymer) film, a TAC (triacetylcellulose) film, or the like can be used.

If necessary, the surface of the base material may be subjected to treatment such as antistatic treatment, mold release treatment, water repellency treatment, water absorption treatment, antibacterial deodorant treatment, antibacterial treatment, and ultraviolet shielding treatment. .

Examples of the method of applying the urethane resin composition of the present invention to the base material include coating methods using an applicator, bar coater, knife coater, T-die coater, roll coater, and the like.

Examples of the method for drying the applied urethane resin composition include a method of drying at a temperature of 50 to 140° C. for 30 seconds to 10 minutes.

The thickness of the obtained film is appropriately determined depending on the intended use, and is, for example, in the range of 0.001 to 10 mm.

When the film is used for a leather-like sheet, it has a 100% modulus of 9 MPa in a tensile test at a crosshead speed of 10 mm/sec, because it provides even better abrasion resistance. 11 to 20 MPa is more preferable. A method for measuring the 100% modulus value of the film will be described in Examples.

In order to obtain a synthetic leather using the film, it is preferable to use the film as a skin layer or a topcoat layer of the synthetic leather.

Examples of the method for producing the synthetic leather include a method in which a surface treatment layer formed on a release paper and the film are laminated by a known method. As a material for forming the surface treatment layer, for example, a solvent-based urethane resin, a water-based urethane resin, a water-based acrylic resin, or the like can be used. Moreover, you may use a well-known adhesive agent for the said bonding as needed.

As described above, the urethane resin composition of the present invention is excellent in oleic acid resistance, low-temperature flexibility, and mechanical strength. Therefore, the urethane resin composition of the present invention can be suitably used as a material for manufacturing synthetic leather, clothing, support pads, polishing pads, etc., and can be particularly suitably used as a material for synthetic leather. can.

The present invention will be described in more detail below using examples.

[Example 1]
Polycarbonate diols (1,9-nonanediol (C9 straight chain) and 2-methyl-1,8-octanediol (C9 branched) were added to a nitrogen-purged four-necked flask equipped with a stirrer, reflux condenser and thermometer. Raw materials, [C9 linear/C9 branch] (hereinafter, molar ratio) = 65/35, number average molecular weight: 2,000, hereinafter abbreviated as “PC1”) 10 parts by mass, polycarbonate diol ( ,4-butanediol (C4) and 1,6-hexanediol (C6) as raw materials, [C4/C6] (hereinafter, molar ratio) = 90/10, number average molecular weight: 2,000, hereinafter " 180 parts by mass of polytetramethylene glycol (number average molecular weight; 2,000, hereinafter abbreviated as “PTMG”). Dehydration was carried out at 130°C. After dehydration, while cooling to 50° C., 130 parts by mass of N,N-dimethylformamide (hereinafter abbreviated as “DMF”) was added and sufficiently stirred. After stirring, 33 parts by mass of 4,4′-dicyclohexylmethane diisocyanate (hereinafter abbreviated as “H12MDI”), 9 parts by mass of hexamethylene diisocyanate (hereinafter abbreviated as “HDI”) and 0 stannous octylate. 1 part by mass was added and reacted at 75° C. to obtain an organic solvent solution of a urethane prepolymer having an isocyanate group at the molecular end. Next, 328 parts by mass of DMF and 153 parts by mass of ethyl acetate are added to the organic solvent solution of the urethane pre-prepolymer, cooled to 35° C., and 12 parts by mass of isophoronediamine (hereinafter abbreviated as “IPDA”) are added. The polyurethane resin was extended by stirring and mixing. Next, 1 part by mass of N,N-dibutylamine and 153 parts by mass of isopropyl alcohol were added and mixed to obtain a urethane resin composition.

[Example 2]
Polycarbonate diols (1,9-nonanediol (C9 straight chain) and 2-methyl-1,8-octanediol (C9 branched) were added to a nitrogen-purged four-necked flask equipped with a stirrer, reflux condenser and thermometer. Raw materials, [C9 straight chain/C9 branched] (hereinafter, molar ratio) = 15/85, number average molecular weight: 2,000, abbreviated as “PC2” hereinafter) is 39 parts by mass, and PC1 is 156 parts. Parts by mass were added, and dehydration was carried out at 120 to 130° C. at a reduced pressure of 0.095 MPa. After dehydration, 128 parts by mass of DMF was added while cooling to 50°C, and the mixture was sufficiently stirred. After stirring, 37 parts by mass of H12MDI, 6 parts by mass of HDI and 0.1 part by mass of stannous octylate are added and reacted at 75°C to form an organic urethane prepolymer having an isocyanate group at the molecular end. A solvent solution was obtained. Next, 324 parts by mass of DMF and 151 parts by mass of ethyl acetate were added to the organic solvent solution of the urethane pre-prepolymer, cooled to 35° C., 12 parts by mass of IPDA were added, and mixed with stirring to extend the polyurethane resin. . Next, 1 part by mass of N,N-dibutylamine and 151 parts by mass of isopropyl alcohol were added and mixed to obtain a urethane resin composition.

[Example 3]
167 parts by mass of PC2 and 124 parts by mass of PC1 were added to a nitrogen-substituted four-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, and dehydration was performed at 120 to 130°C at a reduced pressure of 0.095 MPa. . After dehydration, 124 parts by mass of DMF was added while cooling to 50°C, and the mixture was sufficiently stirred. After stirring, 34 parts by mass of isophorone diisocyanate (hereinafter abbreviated as “IPDI”), 6 parts by mass of HDI and 0.1 part by mass of stannous octylate are added, and reacted at 75° C. to obtain An organic solvent solution of a urethane prepolymer having an isocyanate group at the molecular end was obtained. Next, 325 parts by mass of DMF and 150 parts by mass of ethyl acetate are added to the organic solvent solution of the urethane pre-prepolymer, cooled to 35° C., and 4,4′-dicyclohexylmethanediamine (hereinafter abbreviated as “H12MDA”). ) was added and mixed with stirring to extend the polyurethane resin. Next, 1 part by mass of N,N-dibutylamine and 150 parts by mass of isopropyl alcohol were added and mixed to obtain a urethane resin composition.

[Example 4]
30 parts by mass of PC1 (made from 1,6-hexanediol (C6), [C6] = 100, number average Molecular weight; After dehydration, 131 parts by mass of DMF was added and sufficiently stirred while cooling to 50°C. After stirring, 32 parts by mass of H12MDI, 13 parts by mass of HDI and 0.1 part by mass of stannous octylate are added and reacted at 75°C to obtain an organic solvent solution of a urethane prepolymer having an isocyanate group at the molecular end. got Next, 331 parts by mass of DMF and 154 parts by mass of ethyl acetate were added to the organic solvent solution of the urethane pre-prepolymer, cooled to 35° C., 13 parts by mass of IPDA were added, and mixed with stirring to extend the polyurethane resin. . Next, 1 part by mass of N,N-dibutylamine and 154 parts by mass of isopropyl alcohol were added and mixed to obtain a urethane resin composition.

[Example 5]
29 parts by mass of PC1 and polycarbonate diol (1,4-butanediol (C4) and 1,6-hexanediol (C6) as raw materials were placed in a nitrogen-purged four-necked flask equipped with a stirrer, a reflux condenser, and a thermometer. [C4 / C6] (hereinafter, molar ratio) = 70/30, number average molecular weight: 2,000, hereinafter abbreviated as "other PC3". Dehydration was carried out at 120-130°C. After dehydration, 125 parts by mass of DMF was added and sufficiently stirred while cooling to 50°C. After stirring, 30 parts by mass of IPDI, 10 parts by mass of HDI and 0.1 part by mass of stannous octylate are added and reacted at 75° C. to form an organic urethane prepolymer having an isocyanate group at the molecular end. A solvent solution was obtained. Next, 330 parts by mass of DMF and 152 parts by mass of ethyl acetate were added to the organic solvent solution of the urethane pre-prepolymer, cooled to 35° C., 19 parts by mass of H12MDA were added, and mixed with stirring to extend the polyurethane resin. . Next, 1 part by mass of N,N-dibutylamine and 152 parts by mass of isopropyl alcohol were added and mixed to obtain a urethane resin composition.

[Example 6]
28 parts by mass of PC2 and 159 parts by mass of PC3 were added to a nitrogen-substituted four-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, and dehydration was performed at 120 to 130°C at a reduced pressure of 0.095 MPa. . After dehydration, 122 parts by mass of DMF was added while cooling to 50°C, and the mixture was sufficiently stirred. After stirring, 31 parts by mass of IPDI, 8 parts by mass of HDI, and 0.1 part by mass of stannous octoate are added and reacted at 75° C. to form an organic urethane prepolymer having an isocyanate group at the molecular end. A solvent solution was obtained. Next, 320 parts by mass of DMF and 147 parts by mass of ethyl acetate were added to the organic solvent solution of the urethane pre-prepolymer, cooled to 35° C., 18 parts by mass of H12MDA were added, and mixed with stirring to extend the polyurethane resin. . Next, 1 part by mass of N,N-dibutylamine and 147 parts by mass of isopropyl alcohol were added and mixed to obtain a urethane resin composition.

[Comparative Example 1]
118 parts by mass of PC1 and 78 parts by mass of PC3 were added to a nitrogen-substituted four-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, and dehydration was performed at 120 to 130°C at a reduced pressure of 0.095 MPa. . After dehydration, 127 parts by mass of DMF was added while cooling to 50°C, and the mixture was sufficiently stirred. After stirring, 31 parts by mass of IPDI, 8 parts by mass of HDI, and 0.1 part by mass of stannous octoate are added and reacted at 75° C. to form an organic urethane prepolymer having an isocyanate group at the molecular end. A solvent solution was obtained. Next, 329 parts by mass of DMF and 152 parts by mass of ethyl acetate were added to the organic solvent solution of the urethane pre-prepolymer, cooled to 35° C., 17 parts by mass of H12MDA were added, and mixed with stirring to extend the polyurethane resin. . Next, 1 part by mass of N,N-dibutylamine and 152 parts by mass of isopropyl alcohol were added and mixed to obtain a urethane resin composition.

[Comparative Example 2]
190 parts by mass of other PC2 was placed in a four-necked flask equipped with a stirrer, a reflux condenser and a thermometer and dehydrated at 120 to 130° C. at a reduced pressure of 0.095 MPa. After dehydration, 127 parts by mass of DMF was added and sufficiently stirred while cooling to 50°C. After stirring, 40 parts by mass of H12MDI, 6 parts by mass of HDI and 0.1 part by mass of stannous octylate are added and reacted at 75°C to form an organic urethane prepolymer having an isocyanate group at the molecular end. A solvent solution was obtained. Next, 325 parts by mass of DMF and 151 parts by mass of ethyl acetate were added to the organic solvent solution of the urethane pre-prepolymer, cooled to 35° C., 14 parts by mass of IPDA were added, and mixed with stirring to extend the polyurethane resin. . Next, 1 part by mass of N,N-dibutylamine and 151 parts by mass of isopropyl alcohol were added and mixed to obtain a urethane resin composition.

[Comparative Example 3]
A urethane resin composition was obtained in the same manner as in Example 1, except that IPDA was not used.

[Method for measuring number average molecular weight]
The number average molecular weights of polyols and the like used in Examples and Comparative Examples are values measured under the following conditions by a gel permeation chromatography (GPC) method.

Measuring device: high-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.
"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 Book "TSKgel G2000" (7.8 mm I.D. x 30 cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40°C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL/min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: A calibration curve was created using the following standard polystyrene.

(standard polystyrene)
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-550" manufactured by Tosoh Corporation

[Method for measuring mechanical strength]
A liquid mixture obtained by blending 100 parts by mass of the urethane resin composition obtained in Examples and Comparative Examples with 40 parts by mass of DMF was dried on a flat release paper ("EK-100D" manufactured by Lintec Co., Ltd.). A film was prepared by coating to a thickness of 30 microns and drying at 90° C. for 2 minutes and then at 120° C. for 2 minutes. Next, the resulting film was cut into strips with a width of 5 mm and a length of 50 mm. The 100% modulus (MPa) of the test piece was measured under the conditions of a head speed of 10 mm/sec. The chuck-to-chuck distance at this time was set to 40 mm. Mechanical strength was evaluated as follows from the obtained 100% modulus value.
"A": 5 MPa or more "B": less than 5 MPa

[Method for measuring resistance to oleic acid]
A film was prepared in the same manner as in [Method for measuring mechanical strength]. Next, the film was cut into strips of 5 mm in width and 50 mm in length, immersed in oleic acid at room temperature for 24 hours, taken out, and oleic acid adhering to the surface was lightly wiped off with a paper cloth. Then, using a tensile tester "Autograph AG-I" (manufactured by Shimadzu Corporation), in an atmosphere at a temperature of 23 ° C., a crosshead speed of 10 mm / sec, a distance between chucks of 40 mm. The stress at 100% elongation was measured. The value obtained by dividing this stress by the 100% modulus value measured in the above [Method for measuring mechanical strength] was taken as the retention rate of the 100% modulus value, and the oleic acid resistance was evaluated as follows.
"A": Retention rate is 40% or more "B": Retention rate is 30% or more and less than 40% "C": Retention rate is less than 30%

[Method for measuring low-temperature flexibility]
A liquid mixture consisting of 100 parts by mass of the urethane resin composition obtained in Examples and Comparative Examples, 40 parts by mass of DMF, 30 parts by mass of methyl ethyl ketone, and 20 parts by mass of a colorant "Dylac L-1770S" manufactured by DIC Corporation. was coated on a release paper so that the film thickness after drying was 30 microns, and dried at 90°C for 2 minutes and further at 120°C for 2 minutes to form a film on the release paper. Next, on this film, 100 parts by mass of urethane resin "Crisbon TA-205FT" manufactured by DIC Corporation, 60 parts by mass of DMF, and 12 parts by mass of polyisocyanate cross-linking agent "Barnock DN-950" manufactured by DIC Corporation. A mixed solution of 1 part by mass of tin catalyst “Accel T-81E” manufactured by DIC Corporation was applied so that the film thickness after drying was 60 microns, and dried at 100° C. for 1 minute. Next, a polyester base fabric was put thereon and pressed with a laminator at 120° C., aged at 40° C. for 3 days, and the release paper was peeled off to obtain a synthetic leather.
This synthetic leather is subjected to a flexibility test (-30 ° C., 100 times / minute) with a flexometer (manufactured by Yasuda Seiki Seisakusho Co., Ltd. "Flexometer with low temperature chamber") until cracks occur on the surface of the synthetic leather. The number of times was measured and evaluated as follows.
"A": 20,000 times or more "B": 10,000 times or more and less than 20,000 times "C": Less than 10,000 times

Abbreviations in Tables 1 and 2 are explained.
"Mn"; number average molecular weight "NCO"; polyisocyanate

It was found that Examples 1 to 6, which are the urethane resin compositions of the present invention, are excellent in oleic acid resistance, low-temperature flexibility, and mechanical strength. In particular, the low-temperature flexibility is a very severe test at -30°C, but the synthetic leather having the coating of the urethane resin composition of the present invention was less likely to crack.

On the other hand, Comparative Example 1, in which the amount of polycarbonate polyol (A) used exceeds the range specified in the present invention, was poor in mechanical strength and resistance to oleic acid.

Comparative Example 2 is an embodiment in which the polycarbonate polyol (A) is not used, but the olein resistance and low-temperature flexibility were insufficient.

Comparative Example 3, in which the chain elongation agent (Y) having an amino group was not used, was poor in mechanical strength and oleic acid resistance.

Claims (6)

A polyol (X) containing 1 to 50% by mass of a polycarbonate polyol (A) made from a glycol having 8 to 11 carbon atoms, a chain extender (Y) having an amino group, and a polyisocyanate (Z) are essential. A urethane resin composition containing a urethane resin as a raw material,
The glycol in the polycarbonate polyol (A) contains a linear glycol and a glycol having a branched structure,
A urethane resin composition, wherein the polyol (X) further contains a polycarbonate polyol (B) made from a glycol having 4 to 6 carbon atoms . Claim 1, wherein the molar ratio [(C8-11 linear chain)/(C8-11 branched chain)] between the linear glycol and the branched glycol is in the range of 10/90 to 90/10. urethane resin composition. The urethane resin composition according to claim 1 or 2, wherein the polycarbonate polyol (A) has a number average molecular weight in the range of 1,500 to 3,500. The urethane resin composition according to any one of claims 1 to 3 , wherein the polyisocyanate (Z) contains 10 mass% or more of an aliphatic polyisocyanate. A film characterized by being formed from the urethane resin composition according to any one of claims 1 to 4 . A synthetic leather comprising the film according to claim 5 .