Curable composition and synthetic leather

Abstract

Provided are: a curable composition which is capable of providing a synthetic leather having good low-temperature characteristics and an excellent balance of physical properties such as softness (texture), chemical resistance, and heat resistance; and a synthetic leather. A curable composition containing component (a): a polycarbonate polyol having a hydroxyl value of 40-75 mgKOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100-280 mgKOH / g, component (c): a polyether polyol, component (d): a polyester polyol, and component (e): a polyisocyanate having an average number of functional groups per molecule of 2-6, the total amount of the component (a) and the component (b) is 30-70 mass% with respect to the total amount of all polyol components in the composition.

Description

Technical Field

[0001] The present invention relates to a curable composition and synthetic leather. Background Art

[0002] As conventional synthetic leather, there is synthetic leather obtained by applying a polyurethane resin solution obtained by polymerizing a polyether polyol such as polypropylene glycol or polytetramethylene glycol to a fibrous substrate or a film-forming plate and coagulating it in water. Although these synthetic leathers are excellent in flexibility and texture, they are easily decomposed by components such as sweat, and there are problems with durability. In addition, there is synthetic leather obtained by using a polyurethane resin solution and coagulating it, and the polyurethane resin solution is polymerized using a polyester polyol obtained by reacting a hydroxy compound with a dibasic acid. This synthetic leather has problems with hydrolysis resistance.

[0003] As synthetic leather for solving these problems, for example, Patent Document 1 discloses synthetic leather obtained from a polyurethane resin polymerized using a polycarbonate diol. Specifically, Patent Document 1 discloses a porous sheet-like material containing or joined with a urethane composition in and / or on a fiber substrate, and the urethane composition includes a polyurethane formed from a polycarbonate diol, an organic isocyanate, and a low molecular weight diol, and a polyurethane formed from a polyester-based diol, an organic diisocyanate, and a low molecular weight diol.

[0004] Patent Document 2 discloses a porous sheet material obtained by applying a solution of a polyurethane resin formed from a high molecular weight diol, an organic isocyanate, and an extender as needed to a substrate by a wet film-forming method. The porous sheet material is characterized in that the high molecular weight diol is a mixed diol of a polycarbonate diol and a polyester diol, and the polycarbonate diol is a copolymerized polycarbonate diol formed from 1,4-butanediol and one or more other alkane diols having 4 to 6 carbon atoms, and based on the total molar amount of the diol, the diol contains 50 to 90 mol% of 1,4-butanediol, the number average molecular weight of the copolymerized polycarbonate diol is 500 to 5000, and the coagulation value of the polyurethane resin is 7 to 14.

[0005] Patent Document 3 discloses a synthetic leather surface coating layer using a polyurethane resin formed from a polyester polycarbonate diol obtained by transesterification of an aliphatic oligocarbonate diol and a polyester polyol, a polyisocyanate, and an extender, and the aliphatic oligocarbonate diol is obtained by transesterification of an aliphatic diol and a dialkyl carbonate, and the polyester polyol is obtained by ring-opening polyaddition of a cyclic ester compound using a compound having an active hydrogen group as an initiator.

[0006] Patent Document 4 discloses a porous sheet material obtained by wet coagulation, which is characterized in that it is obtained by reacting a high molecular diol, an organic isocyanate, and a chain extender. The high molecular diol includes a polycarbonate diol (a1) formed from an alkane diol having 4 to 6 carbon atoms and a polycarbonate diol (a2) formed from an alkane diol having 7 to 12 carbon atoms. Both of the aforementioned polycarbonate diols are copolymer polycarbonate diols, and the mass percentage % of (a1) with respect to the total mass of (a1) and (a2) is 10% or more and 80% or less.

[0007] Patent Document 5 discloses a synthetic leather, which includes a fiber fabric and a surface layer formed from a surface layer material forming composition for a fiber laminate. The synthetic leather is characterized in that in the surface layer material forming composition for a fiber laminate composed of a main agent and a curing agent, the main agent is a polycarbonate diol obtained from 1,6 - hexanediol and a low molecular carbonate, and the curing agent includes a modified polyisocyanate (B1) of hexamethylene diisocyanate having a number average molecular weight of 350 to 500 and an average functional group number (f) of 2 ≤ f < 3 and an isocyanurate - modified polyisocyanate (B2) of hexamethylene diisocyanate with f ≥ 3, (B1):(B2) = 50:50 to 95:5 (mass ratio), and neither the main agent nor the curing agent contains an organic solvent.

[0008] However, although the synthetic leathers disclosed in Patent Documents 1 to 5 have hydrolysis resistance, in applications that require high durability such as automotive seats, the sweat resistance is insufficient.

[0009] Therefore, Patent Document 6 proposes a synthetic leather that uses a specific polycarbonate diol (a copolymer polycarbonate diol derived from 1,5 - pentanediol and 1,6 - hexanediol) in order to provide a synthetic leather with excellent balance of physical properties such as sweat resistance and softness, and that does not generate cracks or wrinkles even during storage. However, the polycarbonate diol described in Patent Document 6 requires the use of a large amount of organic solvents during polyurethane polymerization, and further improvement is desired from the perspective of environmental burden.

[0010] In Patent Document 7, a polyurethane for synthetic leather with excellent physical property balance in terms of flexibility, chemical resistance, low-temperature characteristics, heat resistance, and touch is proposed. Here, a polyurethane for synthetic leather is proposed, which is characterized in that it is a polyurethane for synthetic leather obtained by reacting at least (a) a compound having two or more isocyanate groups in one molecule, (b) a chain extender, and (c) a polycarbonate diol. The (c) polycarbonate diol has a hydroxyl value of 20 mg-KOH / g or more and 45 mg-KOH / g or less, a glass transition temperature measured by a differential scanning calorimeter of -30°C or less, and an average carbon atom number of the dihydroxy compound obtained by hydrolyzing the polycarbonate diol of 3 or more and 5.5 or less. However, the polyurethane for synthetic leather disclosed in Patent Document 7 also requires the use of a large amount of organic solvents during polyurethane polymerization, which is not ideal from the perspective of environmental burden.

[0011] In recent years, environmentally friendly polyurethanes have been proposed. For example, Patent Document 8 proposes a two-component and solvent-free polyurethane for synthetic leather, which is characterized in that it contains a urethane prepolymer composition and a polyisocyanate crosslinking agent having an NCO content of 5 to 35% by mass and an average hydroxyl value of 90 to 150 equivalent% relative to the urethane prepolymer composition. The urethane prepolymer composition is characterized in that it is a urethane prepolymer composition used by reacting a crosslinking agent with active hydrogen in its components and polymerizing to a high molecular weight, and contains at least 20 to 80% by mass of a hydroxyl-terminated urethane prepolymer having a hydroxyl value of 10 to 100 mgKOH / g. Further, as a medium for the polymer, it contains 20 to 80% by mass of an oligomer having a hydroxyl value of 20 to 400 mgKOH / g and not having a urethane bond and capable of crosslinking with the above crosslinking agent, and the non-volatile component is substantially 100%, and the urethane prepolymer composition is liquid at least at a temperature of 30°C.

[0012] However, the urethane prepolymer composition for synthetic leather disclosed in Patent Document 8 uses ether-based polyols such as poly-THF and THF-neopentyl glycol copolymer polyols having a hydroxyl value of 20 to 400 mgKOH / g as oligomers not having a urethane bond in order to achieve solvent-free, and thus has problems of reduced heat resistance and limited uses.

[0013] Prior Art Documents

[0014] Patent Documents

[0015] Patent Document 1: Japanese Patent No. 3142102

[0016] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2003-119314

[0017] Patent Document 3: Japanese Patent Application Laid-Open No. 2004-346094

[0018] Patent Document 4: Japanese Patent No. 4177318

[0019] Patent Document 5: Japanese Patent Application Laid-Open No. 2009-185260

[0020] Patent Document 6: Japanese Patent Application Laid-Open No. 2013-108196

[0021] Patent Document 7: Japanese Patent Application Laid-Open No. 2016-8234

[0022] Patent Document 8: Japanese Patent Application Laid-Open No. 2014-105250 Summary of the Invention

[0023] Problems to be Solved by the Invention

[0024] In order to solve the above problems, an object of the present invention is to provide a curable composition for synthetic leather that can provide excellent physical property balance of low-temperature characteristics, flexibility (touch feeling), chemical resistance, and heat resistance, and a synthetic leather obtained by using the same.

[0025] Solutions to the Problems

[0026] As a result of intensive studies by the present inventors, it has been found that a curable composition containing a polycarbonate diol having a specific structure, a polyether polyol, and a polyester polyol, or a specific isocyanate group-terminated prepolymer composition or a hydroxyl group-terminated prepolymer derived from these polyols and containing a specific polyisocyanate can provide excellent physical property balance of flexibility (touch feeling), chemical resistance, low-temperature flexibility, and heat resistance, and further can suppress the use of solvents for manufacturing an environmentally friendly synthetic leather. Thus, the present invention has been completed.

[0027] That is, the present invention includes the following aspects.

[0028] <1> A curable composition comprising:

[0029] Component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g,

[0030] Component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g,

[0031] Component (c): a polyether polyol,

[0032] Component (d): a polyester polyol, and

[0033] Component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6,

[0034] The total amount of the aforementioned component (a) and the aforementioned component (b) is 30% by mass to 70% by mass relative to the total amount of all polyol components in the composition.

[0035] <2>The curable composition according to the aforementioned <1>, which contains component (f): an isocyanate group-terminated prepolymer containing units derived from one or more polyols selected from the group consisting of component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, component (c): a polyether polyol, and component (d): a polyester polyol, and units derived from component (e): a polyisocyanate having an average number of functional groups of 2 to 6 per molecule.

[0036] <3>A curable composition, which contains:

[0037] Component (f): an isocyanate group-terminated prepolymer having, as structural units, units derived from one or more polyols selected from the group consisting of component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, component (c): a polyether polyol, and component (d): a polyester polyol, and units derived from component (e): a polyisocyanate having an average number of functional groups of 2 to 6 per molecule; and

[0038] All components among the aforementioned component (a), the aforementioned component (b), the aforementioned component (c), and the aforementioned component (d) that are not included in the structural units of the aforementioned component (f)

[0039] The total amount of the units derived from component (a) and the units derived from component (b) in the structural units of the aforementioned component (f) and the total amount of the aforementioned component (a) and the aforementioned component (b) are 30% by mass to 70% by mass relative to the total amount of all polyol components in the composition.

[0040] <4>A curable composition, which contains:

[0041] Component (h): a hydroxyl group-terminated prepolymer containing units derived from one or more polyols selected from the group consisting of component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, component (c): a polyether polyol, and component (d): a polyester polyol, and units derived from component (e): a polyisocyanate having an average number of functional groups of 2 to 6 per molecule;

[0042] All components among the aforementioned component (a), the aforementioned component (b), the aforementioned component (c), and the aforementioned component (d) that are not included in the structural units of the aforementioned component (h); and

[0043] the aforementioned component (e),

[0044] The total amount of the units derived from component (a) and the units derived from component (b) in the structural units of the aforementioned component (h) and the total amount of the aforementioned component (a) and the aforementioned component (b) are 30% to 70% by mass relative to the total amount of all polyol components in the composition.

[0045] <5>A curable composition comprising:

[0046] Component (f): an isocyanate-terminated prepolymer having units derived from at least one polyol selected from the group consisting of component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, component (c): a polyether polyol, and component (d): a polyester polyol, and units derived from component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6 as structural units;

[0047] Component (h): a hydroxyl-terminated prepolymer containing units derived from at least one polyol selected from the group consisting of component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, component (c): a polyether polyol, and component (d): a polyester polyol, and units derived from component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6; and

[0048] All components among the aforementioned component (a), the aforementioned component (b), the aforementioned component (c), and the aforementioned component (d) that are not included in the structural units of the aforementioned component (f) and the aforementioned component (h); and

[0049] Optionally containing the aforementioned component (e),

[0050] The total amount of the units derived from component (a) and the units derived from component (b) in the structural units of the aforementioned component (f) and the total amount of the units derived from component (a) and the units derived from component (b) in the structural units of the aforementioned component (h) and the total amount of the aforementioned component (a) and the aforementioned component (b) are 30% to 70% by mass relative to the total amount of all polyol components in the composition.

[0051] <6>The curable composition according to any one of <1> to <5> above, wherein the polycarbonate polyol of the above component (a) and the above component (b) contains a repeating unit represented by the following formula (1) and a terminal hydroxyl group.

[0052]

[0053] (In formula (1), R1 is a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group having 2 to 15 carbon atoms.)

[0054] <7>The curable composition according to the above <6>, wherein at least 50 mol% of the repeating units in the repeating unit represented by the above formula (1) contains at least two repeating units selected from formula (2), formula (3), and formula (4).

[0055]

[0056] <8>The curable composition according to any one of <1> to <7> above, which contains component (g): a chain extender.

[0057] <9>The curable composition according to any one of <1> to <8> above, wherein the hydroxyl value of the above component (c): polyether polyol and the hydroxyl value of the above component (d): polyester polyol are each 40 to 75 mgKOH / g.

[0058] <10>The curable composition according to any one of <1> to <9> above, which contains an inactive organic solvent in an amount of 40% by mass or less based on the total amount of the composition.

[0059] <11>The curable composition according to any one of <1> to <10> above, which is used for an adhesive layer for synthetic leather.

[0060] <12>A synthetic leather made of the curable composition according to any one of <1> to <11> above.

[0061] Effects of the Invention

[0062] The curable composition according to the present invention can provide a curable composition capable of providing a synthetic leather having an excellent balance of physical properties such as good low-temperature characteristics, softness (touch), chemical resistance, and heat resistance, and a synthetic leather obtained by using the same. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 is a cross-sectional view of an example of a synthetic leather manufactured using the curable composition of the present invention.

[0064] Figure 2 is a view showing an example of a manufacturing process diagram of a synthetic leather obtained by using the curable composition of the present invention.

[0065] Description of the Reference Numerals

[0066] 1 Release paper

[0067] 2 Epidermal layer

[0068] 3 Adhesive layer

[0069] 4 Substrate (woven fabric)

[0070] 5 Coater (epidermal layer)

[0071] 6 Mixing head (adhesive layer)

[0072] 7 Sheet structure (dry synthetic leather product)

[0073] 8 Coating roll

[0074] 9 Crimping roll

[0075] 10 Take-up roll

[0076] 11 Dryer Detailed Embodiment

[0077] Hereinafter, the method for implementing the present invention (hereinafter abbreviated as "the present embodiment") will be described in detail. It should be noted that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of its gist for implementation.

[0078] The curable composition of the present embodiment contains:

[0079] Component (a): A polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g,

[0080] Component (b): A polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g,

[0081] Component (c): A polyether polyol,

[0082] Component (d): A polyester polyol,

[0083] Component (e): A polyisocyanate having an average number of functional groups of 2 to 6 per molecule,

[0084] The total amount of the aforementioned component (a) and the aforementioned component (b) is 30% to 70% by mass relative to the total amount of all polyol components in the composition. The curable composition of the present embodiment forms polyurethane by curing, that is, by reacting component (a) and components (b), (c), (d), and, if necessary, a chain extender (component (g)) with component (e). The polyurethane obtained by this reaction can be used as synthetic leather. Here, the concept of "synthetic leather" in this specification includes not only synthetic leather using woven / knitted fabrics as the base fabric but also artificial leather using non-woven fabrics as the base fabric.

[0085] The synthetic leather obtained from the curable composition of the present embodiment has good low-temperature characteristics and excellent physical property balance of softness (touch), chemical resistance, and heat resistance. Furthermore, the curable composition of the present embodiment can be made into an environmentally friendly curable composition that reduces the solvent usage or does not require the use of solvents at all when producing such excellent synthetic leather.

[0086] In the curable composition of the present embodiment, component (a), component (b), component (c), component (d), component (e), and, if necessary, component (g) are used.

[0087] Regarding the curable composition of the present embodiment, a mixture obtained by compounding components (a), (b), (c), (d), (e), and, if necessary, component (g) that constitute it can be used as the curable composition. Alternatively, an isocyanate-terminated prepolymer composition obtained by selecting one or more from components (a), (b), (c), (d), and, if necessary, component (g) and reacting them can be prepared, and a mixture obtained by compounding this isocyanate-terminated prepolymer composition with one or more selected from components (a), (b), (c), (d), and, if necessary, component (g) can be used as the curable composition. At this time, two or more kinds of isocyanate-terminated prepolymers can be prepared and compounded separately.

[0088] In addition, regarding the curable composition of the present embodiment, a hydroxyl-terminated prepolymer composition obtained by selecting one or more from components (a), (b), (c), (d), and, if necessary, component (g) and reacting them can be prepared, and a mixture obtained by compounding this hydroxyl-terminated prepolymer composition with one or more selected from components (a), (b), (c), (d), and, if necessary, component (g) can be used as the curable composition. At this time, two or more kinds of hydroxyl-terminated prepolymers can be prepared and compounded separately.

[0089] The composition of the present embodiment includes a curable composition in the following manner. It should be noted that the following manner can be obtained, for example, by the prepolymer method described later.

[0090] As one of the compositions of the present embodiment obtained using an isocyanate group-terminated prepolymer, a curable composition containing the following isocyanate group-terminated prepolymer can be cited.

[0091] Specifically, a curable composition containing component (f): an isocyanate group-terminated prepolymer containing "units derived from one or more polyols selected from the group consisting of component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, component (c): a polyether polyol, and component (d): a polyester polyol", and "units derived from component (e): a polyisocyanate having an average number of functional groups of 2 to 6 per molecule".

[0092] The isocyanate group-terminated prepolymer is obtained by, for example, pre-reacting one or more polyols selected from the group consisting of components (a) to (d) with the polyisocyanate of component (e).

[0093] As an example of such a curable composition containing an isocyanate group-terminated prepolymer, a curable composition containing the isocyanate group-terminated prepolymer of component (f) and all components among the aforementioned components (a), (b), (c), and (d) that are not included in the structural units of the aforementioned component (f) can be prepared. Here, "all components among the aforementioned components (a), (b), (c), and (d) that are not included in the structural units of the aforementioned component (f)" means all of the remaining components not selected from the group consisting of the four components (a) to (d) with respect to the units derived from one or more polyols selected from the group consisting of the four components (a) to (d) that are included as the structural units of component (f). For example, when component (f) has units derived from components (a) and (b), "all components among the aforementioned components (a), (b), (c), and (d) that are not included in the structural units of the aforementioned component (f)" are components (c) and (d).

[0094] The isocyanate group-terminated prepolymer composition of component (f) may contain unreacted components (a), (b), (c), and (d).

[0095] As one of the compositions of the present embodiment obtained using a hydroxyl group-terminated prepolymer, the following curable composition containing a hydroxyl group-terminated prepolymer can be cited.

[0096] Specifically, a curable composition containing:

[0097] Component (h): a hydroxyl-terminated prepolymer containing "units derived from one or more polyols selected from the group consisting of component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mg KOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mg KOH / g, component (c): a polyether polyol, and component (d): a polyester polyol", and "units derived from component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6";

[0098] The isocyanate group-terminated prepolymer of the aforementioned component (f) and / or the aforementioned component (e); and

[0099] All components among the aforementioned component (a), the aforementioned component (b), the aforementioned component (c), and the aforementioned component (d) that are not included in the structural units of the aforementioned component (h) (when the aforementioned component (f) is included, it is all components that are not included in the structural units of the aforementioned (f) and the aforementioned component (h)).

[0100] The aforementioned hydroxyl-terminated prepolymer is obtained, for example, by previously reacting one or more polyols selected from the group consisting of component (a) to component (d) with the polyisocyanate of component (e). The hydroxyl-terminated prepolymer composition of component (h) may contain unreacted components (a), (b), (c), and (d).

[0101] It should be noted that "all components among the aforementioned component (a), the aforementioned component (b), the aforementioned component (c), and the aforementioned component (d) that are not included in the structural units of the aforementioned component (h)" and "all components among the aforementioned component (a), the aforementioned component (b), the aforementioned component (c), and the aforementioned component (d) that are not included in the structural units of the aforementioned component (f) and (h)" mean, in the same manner as above: with respect to the units of one or more polyols selected from the group consisting of the four components of component (a) to component (d) that are included as the structural units of component (h) (or component (f) and component (h)), all of the remaining components not selected from the group consisting of the four components of component (a) to component (d). For example, when component (h) (or component (f) and component (h)) has units derived from component (a) and component (b), "all components among the aforementioned component (a), the aforementioned component (b), component (c), and component (d) that are not included in the structural units of the aforementioned component (h) (or component (f) and component (h))" are components (c) and (d).

[0102] The synthetic leather obtained from the curable composition of this embodiment has good low-temperature characteristics, and excellent physical property balance of softness (touch), chemical resistance, and heat resistance. In addition, the synthetic leather obtained from the curable composition of this embodiment is an environment-friendly synthetic leather that can suppress the use of solvents in manufacturing.

[0103] <Component (a) and component (b)>

[0104] In the curable composition of the present embodiment, at least two polycarbonate polyols (component (a) and component (b)) having different hydroxyl values are used. It is considered that: regardless of the amount of hydroxyl groups, the solubility of two polycarbonate diols having different hydroxyl values in a solvent becomes high. Therefore, compared with other polycarbonate polyols, the production of synthetic leather using a solvent can be suppressed. In addition, it is considered that the advantages of a polycarbonate polyol having a low hydroxyl value (large molecular weight) and a polycarbonate diol having a high hydroxyl value (small molecular weight) are combined in a good balance, and the physical property balance of flexibility (touch), chemical resistance, low-temperature characteristics, and heat resistance is excellent.

[0105] One of the polycarbonate polyols used in the curable composition of the present embodiment is a polycarbonate polyol (component (a)) having a hydroxyl value of 40 to 75 mgKOH / g. The hydroxyl value of component (a) is preferably 45 to 70 mgKOH / g, and more preferably 50 to 65 mgKOH / g.

[0106] By making the hydroxyl value of component (a) 40 mgKOH / g or more, the viscosity of the resulting curable composition is suppressed to be low, and the amount of organic solvent used can be reduced. In addition, by making the hydroxyl value of component (a) 75 mgKOH / g or less, there is a tendency for the flexibility (touch) and low-temperature characteristics of the resulting synthetic leather to be improved.

[0107] In addition, the melt viscosity of component (a) at 50°C is preferably 3000 to 25000 mPa·s, more preferably 5000 to 18000 mPa·s, and further preferably 7000 to 16000 mPa·s. By making the melt viscosity of component (a) at 50°C 3000 mPa·s or more, there is a tendency for the flexibility and low-temperature characteristics of the resulting synthetic leather to be improved. In addition, by making the melt viscosity of component (a) at 50°C 25000 mPa·s or less, the viscosity of the resulting curable composition is suppressed to be low, and the amount of organic solvent used can be reduced.

[0108] One of the polycarbonate polyols used in the curable composition of the present embodiment is a polycarbonate polyol (component (b)) having a hydroxyl value of 100 to 280 mgKOH / g. The hydroxyl value of component (b) is preferably 130 to 250 mgKOH / g, and more preferably 160 to 240 mgKOH / g.

[0109] By making the hydroxyl value of component (b) 100 mgKOH / g or more, the viscosity of the resulting curable composition can be suppressed to a low level, and the amount of organic solvent used can be reduced. In addition, by making the hydroxyl value of component (b) 280 mgKOH / g or less, the softness (touch) and low-temperature properties of the resulting synthetic leather are excellent.

[0110] The melt viscosity of component (b) at 50°C is preferably 150 to 600 mPa·s, more preferably 180 to 500 mPa·s, and further preferably 200 to 400 mPa·s. By making the melt viscosity of component (b) at 50°C 150 mPa·s or more, there is a tendency for the softness (touch) and low-temperature properties of the resulting synthetic leather to be excellent. In addition, by making the melt viscosity of component (b) at 50°C 600 mPa·s or less, the viscosity of the resulting curable composition can be suppressed to a low level, and the amount of organic solvent used can be reduced.

[0111] The average number of hydroxyl groups per molecule of component (a) and component (b) is preferably 1.7 to 3.5, more preferably 1.8 to 3.0, and further preferably 2.0 to 2.5.

[0112] Component (a) and component (b) are each preferably a polycarbonate polyol having a repeating unit represented by formula (1) and a terminal hydroxyl group. In the present embodiment, the structure of the polycarbonate polyol of component (a) and the structure of the polycarbonate polyol of component (b) may be the same structure or different structures.

[0113]

[0114] (In formula (1), R1 represents a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group having 2 to 15 carbon atoms.)

[0115] In component (a) and component (b), in addition to the polycarbonate polyol structure, an ether structure and an ester structure may also be included. When component (a) and component (b) have other structures such as an ether structure or an ester structure, the content of the repeating unit represented by formula (1) in each of component (a) or component (b) is preferably 50 mol% or more, and further preferably 70 mol% or more.

[0116] Component (a) and component (b) are not particularly limited, and for example, a difunctional diol compound, a polyol having three or more functions as needed, and a carbonate can be used as raw materials, and they can be synthesized by, for example, a transesterification reaction described in "Polymer Reviews, Volume 9, Pages 9 to 20", etc.

[0117] The difunctional diol compound used in the transesterification reaction is not particularly limited, and examples thereof include diols having a divalent aliphatic hydrocarbon skeleton or a divalent alicyclic hydrocarbon skeleton with 2 to 15 carbon atoms. Specifically, as the above difunctional diol compound, ethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2-methyl-1,8-octanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 2-isopropyl-1,4-butanediol, 2-ethyl-1,6-hexanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc. can be mentioned.

[0118] These difunctional diol compounds can be used alone or in combination of two or more.

[0119] Among these, from the viewpoint of obtaining a curable composition having excellent softness (feel), chemical resistance, low-temperature properties, and heat resistance, an alkylene glycol having 3 to 10 carbon atoms is preferred, and an alkylene glycol having 4 to 6 carbon atoms is more preferred. In addition, it is preferred to use two or more alkylene glycols in combination.

[0120] By making the number of carbon atoms of the difunctional diol compound 2 or more, the viscosity of the curable composition can be suppressed to be low, the amount of the organic solvent can be reduced, and the softness and low-temperature properties of the obtained synthetic leather tend to be improved. By making the number of carbon atoms of the difunctional diol compound 15 or less, the chemical resistance of the obtained synthetic leather tends to be excellent.

[0121] By using two or more difunctional diol compounds in combination, the regularity of the structural units of the obtained polycarbonate diol is reduced and the crystallinity is reduced, and thus there is a tendency to obtain a polycarbonate diol that is liquid at room temperature (25°C). As a result, there is a tendency to be able to suppress the amount of the organic solvent used.

[0122] In addition, in the present embodiment, as the raw materials of component (a) and component (b), in addition to using difunctional diols, polyol compounds having three or more functional groups can be used as needed.

[0123] As the polyol compound, there is no particular limitation, and examples thereof include trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, glycerin, etc. By using the polyol, there is a tendency that the average number of hydroxyl groups in one molecule of the component (a) and the component (b) can be easily adjusted to the range of 1.7 to 3.5.

[0124] In the present embodiment, preferably, 50 mol% or more of the repeating units represented by the formula (1) contain at least two repeating units selected from the formula (2), the formula (3), and the formula (4). The content of the repeating units of the formula (2), the formula (3), and the formula (4) is preferably 70 mol% or more, and more preferably 80 mol% or more.

[0125]

[0126] By making at least two repeating units selected from the formula (2), the formula (3), and the formula (4) among the repeating units represented by the formula (1) be 50 mol% or more, there is a tendency that on the basis of excellent softness (feeling), chemical resistance, low-temperature characteristics, and heat resistance of the obtained synthetic leather, the amount of the inactive organic solvent can be reduced. The upper limit of the proportion (mol%) of at least two repeating units selected from the formula (2), the formula (3), and the formula (4) among the repeating units represented by the formula (1) is not particularly limited, and is usually 100 mol% or less.

[0127] In the present embodiment, when two repeating units are selected from the formula (2), the formula (3), and the formula (4), the proportion of the two repeating units (hereinafter also referred to as "copolymerization ratio") is 90:10 to 10:90 in terms of molar ratio, preferably 70:30 to 30:70, and more preferably 60:40 to 40:60. By making the copolymerization ratio within the above range, there is a tendency that the crystallinity of the polycarbonate diol is reduced, and a synthetic leather having high softness, good low-temperature characteristics, and touch can be obtained. Furthermore, if the copolymerization ratio is within this range, there is a tendency that the amount of the inactive organic solvent can be reduced.

[0128] In this embodiment, when three types of repeating units of formula (2), formula (3), and formula (4) are selected, when the total of the three types of repeating units of formula (2), formula (3), and formula (4) is set to 100 mol%, the proportions of the structural units of formula (2), formula (3), and formula (4) are preferably 5 mol% or more, more preferably 10 mol% or more, and still more preferably 20 mol% or more, respectively. By making the proportion of each of the three types of repeating units of formula (2), formula (3), and formula (4) in the total of the three types of repeating units of formula (2), formula (3), and formula (4) within the above range, there is a tendency for the crystallinity of the polycarbonate diol to decrease, and a synthetic leather having high flexibility, good low-temperature characteristics, and touch can be obtained. Furthermore, by making the proportion of each of the three types of repeating units of formula (2), formula (3), and formula (4) within the above range, there is a tendency for the amount of the non-active organic solvent to be reduced.

[0129] Examples of the carbonate that can be used for components (a) and (b) include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and dibutyl carbonate; diaryl carbonates such as diphenyl carbonate; and alkylene carbonates such as ethylene carbonate, 1,3-propylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, and 1,2-pentylene carbonate. From the viewpoints of ease of acquisition and ease of setting the polymerization reaction conditions, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate are preferably used as the carbonate.

[0130] When manufacturing components (a) and (b), a catalyst may or may not be added. When a catalyst is added, it can be freely selected from the catalysts used in ordinary transesterification reactions. As the catalyst, for example, metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic, and cerium, their metal salts, their metal alkoxides, and organic compounds containing the metal can be used. Among the above catalysts, organic compounds containing titanium, tin, and lead are preferred. In addition, the amount of the catalyst is usually 0.00001 to 0.1% of the mass of the bifunctional diol compound as the raw material and the polyol having three or more functional groups that may be included as required.

[0131] As described above, the manufacturing method of components (a) and (b) in this embodiment can use a bifunctional diol compound, a polyol having three or more functional groups as required, and a carbonate as raw materials, and synthesize them by transesterification reaction.

[0132] More specifically, the transesterification reaction is carried out according to the following steps.

[0133] First, one or more difunctional diol compounds at a specified ratio, one or more polyols with three or more functional groups at a specified ratio as required, and one or more carbonates at a specified ratio are mixed, and a transesterification reaction is carried out at a temperature of 100 to 200 °C, preferably 140 to 180 °C, under normal pressure or reduced pressure, in the presence or absence of a transesterification catalyst.

[0134] Next, the alcohol derived from the carbonate generated in the reaction is removed by distillation to obtain a polycarbonate diol with a molecular weight of about 300 to 500 g / mol.

[0135] Next, unreacted carbonate, difunctional diol, and optionally polyols with three or more functional groups can be distilled off under reduced pressure at 130 to 230 °C, preferably 150 to 200 °C, and components (a) and (b) with a desired hydroxyl value can be obtained through a condensation reaction.

[0136] The composition of components (a) and (b) and the average number of hydroxyl groups per molecule can be adjusted by controlling the feeding ratio of each initial component, the amount of each raw material distilled off during production, and the amount of the reaction product.

[0137] As components (a) and (b) used in the present embodiment, commercially available products can be used. There is no particular limitation, and examples include the product name "DURANOL" series manufactured by Asahi Kasei Corporation, the product name "ETERNACOLL" series manufactured by Ube Industries, Ltd., the product name "Kuraray Polyol C" series, "Kuraray PolyolF" series manufactured by Kuraray Co., Ltd., the product name "PLACCEL" series manufactured by Daicel Corporation, the product name "NIPPOLLAN" series manufactured by Tosoh Corporation, the "Oxymer" series manufactured by Perstorp, the product name "BENEBiOL" series manufactured by Mitsubishi Chemical Corporation, etc. They can be used alone or in any combination of two or more.

[0138] <Component (c)>

[0139] In the curable composition of the present embodiment, component (c): polyether polyol is used. By using polyether polyol, it can not only contribute to the softness and low-temperature properties of synthetic leather but also help improve the heat and humidity resistance.

[0140] The polyether polyol used in the curable composition of the present embodiment is not particularly limited, and a polyether polyol with a hydroxyl value of 40 to 75 mgKOH / g is ideal. The hydroxyl value of component (c) is preferably 45 to 70 mgKOH / g, more preferably 50 to 65 mgKOH / g.

[0141] By making the hydroxyl value of component (c) 40 mgKOH / g or more, the viscosity of the resulting curable composition is suppressed to be relatively low, and the amount of the organic solvent used can be reduced. In addition, by making the hydroxyl value of component (c) 75 mgKOH / g or less, there is a tendency that the softness (touch) and low-temperature properties of the resulting synthetic leather are further improved.

[0142] The melt viscosity of component (c) at 50°C is preferably 200 to 2000 mPa·s, more preferably 300 to 1500 mPa·s, and still more preferably 500 to 1000 mPa·s. By making the melt viscosity of component (c) at 50°C 200 mPa·s or more, there is a tendency that the softness and low-temperature properties of the resulting synthetic leather are improved. In addition, by making the melt viscosity of component (c) at 50°C 2000 mPa·s or less, the viscosity of the resulting curable composition can be suppressed to be relatively low, and the amount of the organic solvent used can be reduced.

[0143] The average number of hydroxyl groups in one molecule of component (c) is preferably 1.7 to 3.5, more preferably 1.8 to 3.0, and still more preferably 2.0 to 2.5, respectively.

[0144] The number of main-chain carbon atoms of component (c) is not particularly limited. From the viewpoint of ease of acquisition, the number of main-chain carbon atoms is preferably 2 to 4. Further, from the viewpoint of suppressing the decrease in water resistance caused by the absorption of water by the polyurethane, it is preferable that the content of oxygen atoms is small, and the number of main-chain carbon atoms is more preferably 3 to 4. A single polyether polyol may be used alone, or two or more thereof may be used in combination.

[0145] Specific examples of the polyether polyol are not particularly limited, and examples thereof include polytetramethylene ether glycol, polytetramethylene ether glycol having an alkyl side chain, polytrimethylene ether glycol, polypropylene glycol, polyethylene glycol, and copolymers of two or more of them; random copolymers and block copolymers of ethylene oxide and propylene oxide, or random copolymers and block copolymers of ethylene oxide and butylene oxide. Among them, polytetramethylene ether glycol, polytrimethylene ether glycol, etc. are preferred.

[0146] As the component (c) used in the present embodiment, commercially available products can be used. The commercially available products are not particularly limited, and they can be obtained in the form of, for example, the product names "polytetramethylene ether glycol (PTMG)", "BIO PTMG (BioPTMG)" manufactured by Mitsubishi Chemical, the product name "Terathane" series manufactured by Invista, the "PolyTHF" series manufactured by BASF, the "PTG" series manufactured by Hodogaya Chemical, the "Polymeg" series manufactured by Lyondell Basel, the "Arcol" series manufactured by Bayer, the "EcoTrion" series manufactured by SK Chemical, the "PLONON" series manufactured by NOF Corporation, the "SANNIX" series manufactured by Sanyo Chemical Industries, the "ADEKA POLYETHER" series manufactured by ADEKA, the "POLYLITE" series manufactured by DIC, etc.

[0147] As the component (c), components obtained by any of the following methods (1) to (2) can be mentioned, for example.

[0148] (1) Polyether polyols or polytetramethylene ether glycols obtained by adding a single substance or a mixture of alkylene oxides to a single substance or a mixture of polyols;

[0149] (2) Polyether polyols obtained by reacting polyfunctional compounds with alkylene oxides.

[0150] As the aforementioned polyols, glycerin, propylene glycol, etc. can be mentioned, for example. As the aforementioned alkylene oxides, ethylene oxide, propylene oxide, etc. can be mentioned, for example.

[0151] In the present embodiment, as the starting material of the component (c), in addition to using bifunctional diols, polyol compounds having three or more functions can be used as needed. The polyol compounds are not particularly limited, and examples thereof include trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, glycerin, etc. By using polyols, there is a tendency to easily adjust the average number of hydroxyl groups in one molecule of the component (c) to the range of 1.7 to 3.5.

[0152] <Component (d)>

[0153] In the curable composition of the present embodiment, the component (d): polyester polyol is used. By using the polyester polyol, there is a tendency to not only help improve the adhesion between the layers of the synthetic leather, but also improve the adhesion to polyester fibers, which are representative base fabrics. In addition, it is possible to maintain the physical property balance of softness (touch), chemical resistance, low-temperature characteristics, and heat resistance.

[0154] The component (d) used in the curable composition of the present embodiment is not particularly limited, and a polyester polyol having a hydroxyl value of 40 to 75 mgKOH / g is preferably used. The hydroxyl value of the component (d) is preferably 45 to 70 mgKOH / g, more preferably 50 to 65 mgKOH / g.

[0155] By making the hydroxyl value of the component (d) 40 mgKOH / g or more, the viscosity of the resulting curable composition is suppressed to be low, and the amount of the organic solvent used can be reduced. In addition, by making the hydroxyl value of the component (d) 75 mgKOH / g or less, the softness (touch) and low-temperature characteristics of the resulting synthetic leather tend to be improved.

[0156] Furthermore, the hydroxyl value of the component (c): polyether polyol and the hydroxyl value of the aforementioned component (d): polyester polyol are each preferably 40 to 75 mgKOH / g.

[0157] The melt viscosity of the component (d) at 50 °C is preferably 500 to 7000 mPa·s, more preferably 800 to 5000 mPa·s, and further preferably 1000 to 4000 mPa·s. By making the melt viscosity of the component (d) at 50 °C 500 mPa·s or more, the softness and low-temperature characteristics of the resulting synthetic leather tend to be improved. In addition, by making the melt viscosity of the component (d) at 50 °C 7000 mPa·s or less, the viscosity of the resulting curable composition can be suppressed to be low, and the amount of the organic solvent used can be reduced.

[0158] The average number of hydroxyl groups in one molecule of the component (d) is each preferably 1.7 to 3.5, more preferably 1.8 to 3.0, and further preferably 2.0 to 2.5.

[0159] The component (d) is not particularly limited, and examples thereof include any polyester polyol in the following (1) or (2).

[0160] (1) A polyester polyol resin obtained by a condensation reaction of a single substance or a mixture of two or more dibasic acids with a single substance or a mixture of two or more bifunctional diol compounds and / or polyols;

[0161] (2) A polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone using a bifunctional diol compound and / or polyol.

[0162] The aforementioned dibasic acid is not particularly limited, and examples thereof include carboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, etc.

[0163] As the aforementioned bifunctional diol compound, there is no particular limitation, and examples thereof include ethylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2-methyl-1,8-octanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 2-isopropyl-1,4-butanediol, 2-ethyl-1,6-hexanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc. As the polyol compound, there is no particular limitation, and examples thereof include trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, glycerol, etc.

[0164] The number of main-chain carbon atoms of component (d) is not particularly limited. From the viewpoint of ease of acquisition, the number of main-chain carbon atoms derived from the bifunctional diol compound and the polyol is preferably 2 to 9, and the number of main-chain carbon atoms derived from the dibasic acid is preferably 4 to 10. Further, from the viewpoint of suppressing the decrease in water resistance caused by water absorption of the polyurethane, it is preferable that the content of carbon atoms is large, and the number of main-chain carbon atoms derived from the bifunctional diol compound and the polyol is more preferably 4 to 6, and the number of main-chain carbon atoms derived from the dibasic acid is more preferably 4 to 10. The polyester polyol may be used alone or in combination of two or more.

[0165] As a specific example of component (d), there is no particular limitation, and examples thereof include polyethylene adipate glycol, polypropylene adipate glycol, polybutylene adipate glycol, poly(pentylene adipate) glycol, poly(hexylene adipate) glycol, poly(ethylene glycol butylene adipate) glycol, poly(hexanediol isophthalate adipate) glycol, polyethylene succinate glycol, polybutylene succinate glycol, poly(ethylene glycol sebacate) glycol, poly(butylene glycol sebacate) glycol, poly(3-methyl-1,5-pentanediol adipate) glycol, poly-γ-butyrolactone glycol, poly-δ-valerolactone glycol, poly-ε-caprolactone glycol, a condensate of 1,6-hexanediol and dimer acid, a castor oil-modified polyol, etc. Among them, polyethylene adipate glycol, polypropylene adipate glycol, polybutylene adipate glycol, poly(pentylene adipate) glycol, poly(hexylene adipate) glycol, poly(3-methyl-1,5-pentanediol adipate) glycol, and poly-ε-caprolactone glycol are preferred, and poly(hexylene adipate) glycol, poly(3-methyl-1,5-pentanediol adipate) glycol, and poly-ε-caprolactone glycol are more preferred.

[0166] The manufacturing method of component (d) in the present embodiment can be carried out as described above. A difunctional diol compound, a polyol having three or more functional groups as needed, and a dibasic acid can be used as raw materials, and they are synthesized by transesterification reaction.

[0167] More specifically, the transesterification reaction is carried out according to the following steps.

[0168] First, one or more difunctional diol compounds in a specified ratio, one or more polyols having three or more functional groups in a specified ratio as needed, and one or more dibasic acids in a specified ratio are mixed. Under normal pressure or reduced pressure, with or without a transesterification catalyst, the transesterification reaction is carried out at a temperature of 100 to 280 °C, preferably 140 to 220 °C.

[0169] Next, by distilling off the condensation reaction of the water generated in the reaction, component (d) with a desired hydroxyl value can be obtained.

[0170] The composition of component (d) and the average number of hydroxyl groups per molecule can be adjusted by controlling the feeding ratio of each initial component, the amount of each raw material distilled off during production, and the amount of the reaction product.

[0171] As component (d) used in the present embodiment, commercially available products can be used. There is no particular limitation on such commercially available products. Examples include the product name "KYOWAPOL" (Japanese: キョーワポール) series manufactured by Kyowa Hakko Chemical Co., Ltd., the product name "Kuraray Polyol" series manufactured by Kuraray Co., Ltd., the product name "PLACCEL" series manufactured by Daicel Corporation, the product name "POLYLITE" series manufactured by DIC Corporation, the product name "NIPPOLLAN" series manufactured by Tosoh Corporation, the "Desmophen" series manufactured by Bayer Corporation, etc.

[0172] In the present embodiment, regarding the preferred mass ratio of component (a) to component (b), based on a total of 100 mass% of component (a) and component (b), the proportion of component (a) contained therein is preferably 20 to 80 mass%, more preferably 30 to 70 mass%, and still more preferably 40 to 60 mass%. By making the proportion of component (a) 20 mass% or more, the softness (touch) and low-temperature characteristics of the resulting synthetic leather tend to be more excellent. By making the proportion of component (a) 80 mass% or less, the viscosity of the resulting curable composition tends to be suppressed to a low level, and the amount of organic solvent used can be reduced.

[0173] In the curable composition of the present embodiment, the polyols of components (a), (b), (c), and (d) may be used in combination with polyols other than components (a), (b), (c), and (d) as needed. Here, the polyols other than components (a), (b), (c), and (d) are not particularly limited as long as they are substances commonly used in the production of polyurethanes, and examples thereof include acrylic polyols, polyolefin polyols, castor oil polyols, polycarbonate polyols other than components (a) and (b), and the like.

[0174] In the curable composition of the present embodiment, the total amount of the aforementioned component (a) and the aforementioned component (b) is 30% by mass to 70% by mass relative to the total amount of all polyol components in the composition. The mass ratio of component (a) and component (b) to the mass obtained by adding component (a) and component (b) to other polyols (the total amount of all polyol components in the composition) is more preferably 40% by mass or more. By setting the mass ratio of component (a) and component (b) to 30% by mass or more, there is a tendency for the balance of softness (touch), chemical resistance, low-temperature characteristics, and heat resistance to be excellent when producing synthetic leather. On the other hand, adding other polyols helps to reduce the viscosity of the curable composition of the present embodiment, and they can be used in combination within the range that does not impair the performance.

[0175] It should be noted that when the curable composition of the present embodiment contains a prepolymer of component (f) or a prepolymer of component (h), it is as follows.

[0176] i) In the case of containing a prepolymer of component (f)

[0177] The total amount of the units derived from component (a) and the units derived from component (b) in the structural unit of component (f) and the total amount of component (a) and component (b) are 30% by mass to 70% by mass relative to the total amount of all polyol components in the composition.

[0178] ii) In the case of containing a prepolymer of component (h)

[0179] The total amount of the units derived from component (a) and the units derived from component (b) in the structural unit of component (h) and the total amount of component (a) and component (b) are 30% by mass to 70% by mass relative to the total amount of all polyol components in the composition.

[0180] iii) In the case of containing a prepolymer of component (f) and a prepolymer of component (h)

[0181] The total amount of the units derived from component (a) and the units derived from component (b) in the structural units of component (f), the total amount of the units derived from component (a) and the units derived from component (b) in the structural units of component (h), and the total amount of component (a) and component (b) are 30% by mass to 70% by mass relative to the total amount of all polyol components in the composition.

[0182] It should be noted that the total amount of the units derived from component (a) or component (b) in the prepolymer can be calculated by, for example, a method of measuring using an infrared spectrophotometer (IR), a method of dissolving it in a deuterated solvent and measuring using a nuclear magnetic resonance apparatus (1H-NMR, 13C-NMR), an analysis method for the composition of the polyol described later, gel permeation chromatography (GPC), high performance liquid chromatography (HPLC), and a known analysis method such as matrix-assisted laser desorption / ionization time-of-flight mass spectrometry MALDI-TOFMS or a combination thereof.

[0183] <Component (e)>

[0184] In the curable composition of the present embodiment, a polyisocyanate (component (e)) having an average number of functional groups per molecule of 2 to 6 is used.

[0185] Examples of component (e) in the present embodiment include aromatic diisocyanates such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate and mixtures thereof, diphenylmethane-4,4'-diisocyanate (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3'-dimethyl-4,4'-biphenyl diisocyanate (TODI), polymethylene polyphenylene polyisocyanate (polymeric MDI, PMDI), polycarbodiimide-modified diphenylmethane diisocyanate; aromatic aliphatic diisocyanates such as xylylene diisocyanate (XDI), phenylene diisocyanate; aliphatic diisocyanates such as 4,4'-methylenebis(cyclohexyl isocyanate) (hydrogenated (also known as hydrogenated) MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), cyclohexane diisocyanate (hydrogenated XDI), etc.

[0186] As component (e) used in the present embodiment, a polyisocyanate having an average of 2.1 or more isocyanate groups per molecule can also be used. As the polyisocyanate having an average of 2.1 or more isocyanate groups per molecule, aromatic polyisocyanates such as crude MDI and crude TDI can be used; derivatives of aliphatic isocyanates such as HDI and IPDI, specifically, diisocyanate derivatives such as biuret, urethane, uretdione, and isocyanurate can be used; and polyol adduct types.

[0187] The polyisocyanate having 2.1 or more isocyanate groups in one molecule is not particularly limited. For example, it can be obtained in the form of Sumidur 44S, 44V70 (both manufactured by Sumika Bayer Urethane Co., Ltd.), Desmodur HL (manufactured by Sumika Bayer Urethane Co., Ltd.) which is a copolymer of TDI and HDI, various DURANATE manufactured by Asahi Kasei Corporation, namely DURANATE 24A-100, DURANATE 22A-75PX, DURANATE 18H-70B, DURANATE 21S-75E, DURANATETHA-100, DURANATE TPA-100, DURANATE TKA-100, DURANATE TLA-100, DURANATE TUL-100, DURANATE MFA-75X, DURANATE TSA-100, DURANATE TSS-100, DURANATE TSE-100, DURANATED-101, DURANATE D-201, DURANATE P-301-75E, DURANATE E-402-90T, DURANATE E-402-90T, DURANATE E-405-80T, DURANATE ME20-100, DURANATE 17B-60PX, DURANATE TPA-B80X, DURANATE MF-B60X, DURANATE E-402-B80T, DURANATE ME20-B80S, DURANATE WB40-100, DURANATE WB40-80D, DURANATE WT20-100, DURANATE WT30-100, etc.

[0188] Furthermore, a so-called blocked isocyanate obtained by blocking the component (e) with a known blocking agent such as lower alcohols like butanol and 2-ethylhexanol, methyl ethyl ketoxime, lactams, phenols, imidazoles, active methylene compounds, etc. can also be used.

[0189] When expressed as [isocyanate equivalent of component (e)] / [total hydroxy equivalent of components (a), (b), (c), and (d)], the amount of component (e) is adjusted preferably to be 0.7 to 1.3, more preferably 0.8 to 1.2, and even more preferably 0.9 to 1.1. By making [isocyanate equivalent of component (e)] / [total hydroxy equivalent of components (a), (b), (c), and (d)] be 0.7 or more and 1.3 or less, the molecular weight of the resulting polyurethane can be appropriately controlled, and there is a tendency for excellent mechanical properties such as strength, elongation at break, and abrasion resistance.

[0190] As component (e), aromatic polyisocyanates such as MDI are preferably used. By using aromatic polyisocyanates, there is a tendency to obtain synthetic leather with excellent mechanical properties. When an aromatic polyisocyanate such as MDI is used as component (e) in the curable composition, the curable composition can be mainly suitably used as an adhesive for the base fabric and the epidermis layer of synthetic leather. When an aliphatic polyisocyanate such as hydrogenated MDI is used as component (e) in the curable composition, synthetic leather with excellent weather resistance can be obtained from the curable composition, and thus it can be suitably used as a curable composition for the epidermis layer.

[0191] <Component (g)>

[0192] In the curable composition of the present embodiment, a chain extender: component (g) can be used as needed. Component (g) can be used to adjust physical properties such as the strength, abrasion resistance, and softness of the cured polyurethane. As the chain extender, there is no particular limitation, and examples thereof include short-chain diols such as ethylene glycol, 1,3-propanediol, and 1,4-butanediol; polyols such as trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, and glycerol; diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, toluenediamine, xylylenediamine, diphenyldiamine, diaminodiphenylmethane, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, and isophoronediamine; amino alcohols such as ethanolamine, diethanolamine, and triethanolamine. Among these, as component (g), from the viewpoint of reducing the local reaction with isocyanates, diols and polyols having 2 to 6 carbon atoms are preferred, and diols having 2 to 6 carbon atoms are more preferred. The chain extender can be used singly or in combination of two or more.

[0193] The addition amount of component (g) is preferably 30% by mass or less, more preferably 3% by mass or more and 20% by mass or less, and still more preferably 5% by mass or more and 10% by mass or less, relative to the total of components (a), (b), (c), and (d). Desirably, the amount of isocyanate is also adjusted according to the addition amount of the chain extender. For example, relative to the total of the hydroxy equivalent of components (a), (b), (c), and (d) plus the equivalent of the functional group of component (g), the isocyanate equivalent of component (e) used is adjusted to preferably be 0.7 to 1.3 equivalents, more preferably 0.8 to 1.2 equivalents, and still more preferably 0.9 to 1.1 equivalents.

[0194] <Inactive organic solvent>

[0195] In the curable composition of the present embodiment, an inactive organic solvent may be contained as needed to adjust the workability during the production of urethane. The content of the inactive organic solvent is preferably 40% by mass or less, more preferably 3% by mass or more and 30% by mass or less, and still more preferably 5% by mass or more and 20% by mass or less, relative to the total amount of the curable composition. Adding an inactive organic solvent is effective for reducing the viscosity of the curable composition, improving the workability during the production of synthetic leather, and further improving the appearance of the resulting synthetic leather. However, as long as an expensive solvent recovery device is not introduced, the solvent used in the process will be released into the atmosphere through the drying process, which may lead to an increase in VOC (Volatile Organic Compounds). From the perspective of reducing the environmental burden, it is preferable to suppress the content of the inactive organic solvent to a small amount, and desirably, no solvent is used at all.

[0196] The inactive organic solvent is not particularly limited as long as it is substantially inactive with respect to the polyisocyanate, and preferably does not have active hydrogen. There is no particular limitation on the inactive organic solvent, and examples thereof include hydrocarbons such as pentane, hexane, heptane, octane, decane, petroleum ether, petroleum benzine, ligroine, petroleum spirit, cyclohexane, and methylcyclohexane; fluorine-based inactive liquids such as chlorotrifluoroethane, dichlorodifluoroethane, and perfluoroether; and perfluorocyclohexane, perfluorobutyltetrahydrofuran, perfluorodecalin, perfluoron-butylamine, perfluoropolyether, dimethylpolysiloxane, etc. They can be used alone or in the form of a mixture. As the inactive organic solvent, there can also be mentioned individual substances or mixed solvents such as methyl ethyl ketone (also denoted as MEK), acetone, ethyl acetate, butyl acetate, toluene, xylene, dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, tetrahydrofuran (THF), dioxane, etc.

[0197] <Other additives>

[0198] In the curable composition of the present embodiment, a curing accelerator (catalyst), filler, flame retardant, dye, organic pigment or inorganic pigment, mold release agent, fluidity regulator, plasticizer, antioxidant, ultraviolet absorber, light stabilizer, defoaming agent, leveling agent, colorant, foaming agent, etc. can be added according to various uses.

[0199] There is no particular limitation on the curing accelerator, and amines and metal catalysts can be mentioned.

[0200] There is no particular limitation on the amine-based curing accelerator, and examples thereof include triethylamine as a monoamine, N,N-dimethylcyclohexylamine, tetramethylethylenediamine as a diamine, other triamines, cyclic amines, alkanolamines such as dimethylethanolamine, and ether amines.

[0201] There is no particular limitation on the metal catalyst, and examples thereof include potassium acetate, potassium 2-ethylhexanoate, calcium acetate, lead octoate, dibutyltin dilaurate, tin octoate, bismuth neodecanoate, bismuth oxycarbonate, bismuth 2-ethylhexanoate, zinc octoate, zinc neodecanoate, phosphine, phosphabenzene, etc.

[0202] There is no particular limitation on the filler and pigment, and examples thereof include knitted fabric, glass fiber, carbon fiber, polyamide fiber, mica, kaolin, bentonite, metal powder, azo pigment, carbon black, clay, silica, talc, gypsum, alumina white, barium carbonate, etc.

[0203] As a mold release agent, fluidity regulator, and leveling agent, there is no particular limitation, and examples thereof include silicone, AEROSIL, wax, stearate, and polysiloxanes such as BYK-331 (manufactured by BYK Chemical Co., Ltd.).

[0204] As the additive used in this embodiment, it is preferable to use at least an antioxidant, a light stabilizer, a heat stabilizer, and a flame retardant.

[0205] As the antioxidant, there is no particular limitation, and examples thereof include phosphorus compounds such as phosphoric acid, phosphorous acid, aliphatic, aromatic, or alkyl-substituted aromatic esters, hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonate esters, dialkyl pentaerythritol diphosphite, and dialkyl bisphenol A diphosphite; phenolic derivatives, particularly hindered phenol compounds, sulfur-containing compounds such as thioether-based, dithiocarbamate-based, mercaptobenzimidazole-based, thiocarbanilide-based, and thiodipropionate; and tin-based compounds such as tin maleate and dibutyltin monoxide. They may be used alone or in combination of two or more.

[0206] As the flame retardant, there is no particular limitation, and examples thereof include brominated flame retardants such as tetrabromobisphenol A, decabromodiphenyl ether, octabromodiphenyl ether, hexabromocyclododecane, decabromodiphenylethane, bis(tribromophenoxy)ethane, polydibromophenyl ether, tetrabromophthalic anhydride, TBA carbonate oligomer, brominated polystyrene; halogenated flame retardants such as chlorinated flame retardants like polychlorinated biphenyls, perchloropentacyclodecane, hexachlorocyclopentadiene derivatives; phosphorus-based flame retardants such as triphenyl phosphate, tricresyl phosphate, tris(dimethylphenyl) phosphate, triethyl phosphate, tolyldiphenyl phosphate, dimethyldiphenyl phosphate, tolylbis(2,6-dimethylphenyl) phosphate, 2-ethylhexyl phosphate, dimethylmethyl phosphate, resorcinol bis(diphenyl) phosphate, bisphenol A bis(diphenyl) phosphate, bisphenol A bis(dimethylphenyl) phosphate, diethyl-N,N-bis(2-hydroxyethyl)aminomethyl phosphate, phosphoric amide, organic phosphine oxide, red phosphorus; nitrogen-based flame retardants such as ammonium polyphosphate, phosphazene, cyclophosphazene, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivatives, triazine, melamine cyanurate, succinoguanamine, ethylenebis(melamine), triguanamine, triazine cyanurate salt, melem, melam, tris(β-cyanoethyl) isocyanurate, methylguanamine, guanidine sulfate melamine, guanidine sulfate melem, guanidine sulfate melam; metal salt-based flame retardants such as diphenyl sulfone-3-sulfonic acid potassium, aromatic sulfonimide metal salts, polystyrene sulfonic acid alkali metal salts; hydrated metal-based flame retardants such as aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, barium hydroxide, basic magnesium carbonate, zirconium hydroxide, tin oxide; inorganic-based flame retardants such as silica, alumina, iron oxide, titanium oxide, manganese oxide, magnesium oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide, bismuth oxide, chromium oxide, tin oxide, antimony oxide, nickel oxide, copper oxide, tungsten oxide, zinc borate, zinc metaborate, barium metaborate, zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, zinc stannate; silicone-based flame retardants such as silicone powder, etc. Among them, from the viewpoint of environmental burden, phosphorus-based flame retardants are preferably used.

[0207] <Method for manufacturing curable composition>

[0208] The curable composition of the present embodiment is usually manufactured by a manufacturing method used industrially.

[0209] The curable composition of the present embodiment can be manufactured by, for example, a method of mixing components (a), (b), (c), (d), and (e), and optionally component (g) together and reacting them (hereinafter referred to as "one shot method").

[0210] In addition, as described above, for the curable composition of the present embodiment, a mixture obtained by compounding components (a), (b), (c), (d), and (e), and, if necessary, component (g) can be used as the curable composition. Alternatively, an isocyanate group-terminated prepolymer composition obtained by selecting one or more from components (a), (b), (c), (d), and, if necessary, component (g) and reacting them with component (e) can be prepared, and a mixture obtained by compounding the isocyanate group-terminated prepolymer composition with one or more selected from components (a), (b), (c), (d), and, if necessary, component (g) can be used as the curable composition. At this time, two or more kinds of isocyanate group-terminated prepolymers can be prepared and compounded separately.

[0211] That is, the curable composition of the present embodiment can be manufactured, for example, by the following method: First, components (a) and / or (b) and / or (c) and / or (d) and, if necessary, component (g) are pre-reacted with component (e) to prepare a prepolymer composition having an isocyanate group at the terminal, and then components (a) and / or (b) and / or (c) and / or (d) and, if necessary, component (g) are compounded (hereinafter referred to as the "prepolymer method". One kind or two or more kinds of prepolymers can be used).

[0212] In addition, as described above, a hydroxyl group-terminated prepolymer composition obtained by selecting one or more from components (a), (b), (c), (d), and, if necessary, component (g) and reacting them with component (e) can be prepared, and a mixture obtained by compounding the hydroxyl group-terminated prepolymer composition with one or more selected from components (a), (b), (c), (d), and, if necessary, component (g), component (e), and / or one or more of the isocyanate group-terminated prepolymers prepared as described above can be used as the curable composition. At this time, two or more kinds of hydroxyl group-terminated prepolymers can be prepared and compounded separately.

[0213] That is, the curable composition of the present embodiment can be manufactured, for example, by the following method: First, components (a) and / or (b) and / or (c) and / or (d) and, if necessary, component (g) are pre-reacted with component (e) to prepare a prepolymer composition having a hydroxyl group at the terminal, and then one or more selected from components (a), (b), (c), (d), and, if necessary, component (g), component (e), and / or one or more of the isocyanate group-terminated prepolymers prepared as described above are compounded (hereinafter referred to as the "prepolymer method". One kind or two or more kinds of prepolymers can be used).

[0214] (One-step method)

[0215] When obtaining the curable composition by a one-step method, the amount of component (e) is usually preferably 0.7 to 1.3 equivalents, more preferably 0.8 to 1.2 equivalents, and further preferably 0.9 to 1.1 equivalents in terms of isocyanate equivalent relative to the total hydroxy equivalents of components (a), (b), (c), (d), and (g). By making the amount of component (e) 0.7 equivalent or more and 1.3 equivalents or less, the molecular weight of the resulting polyurethane can be moderately controlled, and there is a tendency for excellent mechanical properties such as strength, elongation, and abrasion resistance. When obtaining the curable composition by a one-step method, for the purpose of improving the workability in manufacturing synthetic leather, an inert organic solvent can be used. Generally, when a polyol (corresponding to components (a), (b), (c), (d), and (g)) and a polyisocyanate (corresponding to component (e)) are mixed, the viscosity of the curable mixture increases with time. By adding an inert organic solvent to the curable composition, there is a tendency to be able to reduce the viscosity of the composition and extend the coatable time.

[0216] When using other additives, the other additives can be added simultaneously when components (a), (b), (c), (d), (g), and (e) are mixed together, or can be premixed into components (a), (b), (c), (d), (g), and (e).

[0217] (Prepolymer method)

[0218] In the prepolymer method, an isocyanate group-terminated prepolymer composition and / or a hydroxy group-terminated prepolymer composition obtained by selecting one or more from components (a), (b), (c), (d), and, if necessary, component (g) and reacting them can be prepared, and a mixture obtained by compounding the isocyanate group-terminated prepolymer composition and / or the hydroxy group-terminated prepolymer composition with one or more selected from components (a), (b), (c), (d), component (e), and, if necessary, component (g) can be used as the curable composition. At this time, two or more kinds of isocyanate group-terminated prepolymers and / or hydroxy group-terminated prepolymer compositions can be prepared and compounded separately.

[0219] Specifically, the following methods can be cited: First, react component (a) and / or component (b) and / or component (c) and / or component (d) with component (g) as needed to prepare a prepolymer composition with an isocyanate group or a hydroxy group at the end (also simply referred to as a prepolymer composition), and then add component (a) and / or component (b) and / or component (c) and / or component (d) and add component (g) and / or component (e) as needed.

[0220] When synthesizing an isocyanate group-terminated prepolymer composition, the ratio of component (a) and / or component (b) and / or component (c) and / or component (d) and / or component (g) to component (e) is adjusted such that the equivalent ratio of the isocyanate groups contained in component (e) to the hydroxyl groups contained in component (a) and / or component (b) and / or component (c) and / or component (d) and / or component (g), [isocyanate equivalent] / [hydroxyl equivalent], becomes 1.5 to 3.0, preferably 1.8 to 2.7, and more preferably 1.9 to 2.3. By making [isocyanate equivalent] / [hydroxyl equivalent] in the synthesis of the isocyanate group-terminated prepolymer 1.5 or more, the molecular weight of the resulting prepolymer is moderately controlled, the viscosity of the prepolymer is suppressed, and the use of organic solvents can be reduced. By making [isocyanate equivalent] / [hydroxyl equivalent] in the synthesis of the isocyanate group-terminated prepolymer 3.0 or less, the unreacted component (e) is suppressed, and the tendency for the resulting polyurethane to harden can be inhibited.

[0221] When synthesizing a hydroxyl group-terminated prepolymer composition, the ratio of component (a) and / or component (b) and / or component (c) and / or component (d) and / or component (g) to component (e) is adjusted such that the equivalent ratio of the hydroxyl groups contained in component (a) and / or component (b) and / or component (c) and / or component (d) and / or component (g) to the isocyanate groups contained in component (e), [hydroxyl equivalent] / [isocyanate equivalent], becomes 1.5 to 3.0, preferably 1.8 to 2.7, and more preferably 1.9 to 2.3. By making [hydroxyl equivalent] / [isocyanate equivalent] in the synthesis of the hydroxyl group-terminated prepolymer 1.5 or more, the molecular weight of the resulting prepolymer is moderately controlled, the viscosity of the prepolymer is suppressed, and the use of organic solvents can be reduced. By making [hydroxyl equivalent] / [isocyanate equivalent] in the synthesis of the hydroxyl group-terminated prepolymer 3.0 or less, there is a tendency for the molecular weight and molecular weight distribution of the polymer to be moderately controlled and the physical properties of the resulting polyurethane to be improved.

[0222] The ratio of the isocyanate group-terminated prepolymer composition obtained by pre-reacting component (a) and / or component (b) and / or component (c) and / or component (d) with component (g) as required to component (e) is preferably 0.7 to 1.3, more preferably 0.8 to 1.2, and further preferably 0.9 to 1.1 in terms of [isocyanate equivalent of the prepolymer composition] / [hydroxyl value equivalent of component (a) and / or component (b) and / or component (c) and / or component (d) and / or component (g)]. By making [isocyanate equivalent of the prepolymer composition] / [hydroxyl value equivalent of component (a) and / or component (b) and / or component (c) and / or component (d) and / or component (g)] 0.7 equivalent or more and 1.3 equivalents or less, there is a tendency to be able to moderately control the molecular weight, strength, elongation, abrasion resistance, etc. of the resulting polyurethane, and the mechanical properties are excellent.

[0223] In addition, the ratio of the hydroxyl group-terminated prepolymer composition to component (e) and / or the isocyanate group-terminated prepolymer is preferably 0.7 to 1.3, more preferably 0.8 to 1.2, and further preferably 0.9 to 1.1 in terms of [hydroxyl value equivalent of the prepolymer composition] / [isocyanate equivalent of component (e) and / or the isocyanate group-terminated prepolymer]. By making [hydroxyl value equivalent of the prepolymer composition] / [isocyanate equivalent of component (e) and / or the isocyanate group-terminated prepolymer] 0.7 equivalent or more and 1.3 equivalents or less, there is a tendency to be able to moderately control the molecular weight, strength, elongation, abrasion resistance, etc. of the resulting polyurethane, and the mechanical properties are excellent.

[0224] When obtaining a curable composition by the prepolymer method, for the purpose of improving the workability in manufacturing synthetic leather, an inert organic solvent can be used. The amount of the inert organic solvent used is preferably 40% by mass or less. If the isocyanate group-terminated prepolymer composition and the polycarbonate polyol are mixed, the viscosity of the curable composition increases with time. By adding an inert organic solvent to the curable composition, there is a tendency to be able to reduce the viscosity of the composition and extend the coatable time.

[0225] When using an inert organic solvent, the viscosity becomes high during the synthesis of the prepolymer. Therefore, it is preferable to add the inert organic solvent to component (a) and / or component (b) and / or component (c) and / or component (d) with component (g) as required before synthesizing the prepolymer, and then carry out the prepolymer reaction. In addition, by using an inert organic solvent during the synthesis of the prepolymer, there is a tendency for the reaction to proceed uniformly.

[0226] When using other additives, the viscosity also increases during the synthesis of the prepolymer. Therefore, it is preferred that: before synthesizing the prepolymer, a non-reactive organic solvent is added in advance to component (a) and / or component (b) and / or component (c) and / or component (d) and component (g) as required, and then the prepolymer reaction is carried out.

[0227] When comparing the one-step method with the prepolymer method, the prepolymer method is easier to adjust the structure of the soft segment part. As a result, there is a tendency for phase separation between the soft segment and the hard segment to occur more easily, and the softness or low-temperature characteristics of the resulting polyurethane are excellent. Therefore, the prepolymer method is preferred.

[0228] <Method for manufacturing synthetic leather>

[0229] Synthetic leather can be manufactured from the curable composition of the present embodiment. As a method for manufacturing synthetic leather from the curable composition of the present embodiment, for example, a wet method in which the curable composition of the present embodiment is coated or impregnated on a substrate (base fabric) and wet-solidified, a dry method in which the curable composition of the present embodiment is coated on a release paper or a substrate (base fabric) and dried, etc. can be cited.

[0230] Furthermore, as a method for manufacturing synthetic leather, the following transfer coating method (a kind of dry method) can also be used: after coating the curable composition of the present embodiment on a release paper to form a skin material, using the curable composition of the present embodiment as an adhesive layer thereon, laminating it with a substrate (base fabric), and then removing the release paper. That is, the composition of the present embodiment can be used for an adhesive layer for synthetic leather.

[0231] The curable composition of the present embodiment can suppress the amount of non-reactive organic solvent used, and therefore is suitable for the dry method (transfer coating method).

[0232] Taking the dry method as an example, the method for manufacturing synthetic leather will be described below.

[0233] As the substrate (base fabric), various substances can be used, and for example, a fibrous substrate can be cited. As the fibrous substrate, a fibrous aggregate formed by shaping fibers into a non-woven fabric, a knitted fabric, a woven fabric, a napped fabric obtained by performing a buffing treatment, etc., or a substrate obtained by binding the fibers of the fibrous aggregate with an elastic polymer can be cited. As the fibers used in the fibrous aggregate, natural fibers such as cotton, hemp, and wool; regenerated or semi-synthetic fibers such as rayon and acetate; synthetic fibers such as polyamide, polyester, polyacrylonitrile, polyvinyl alcohol, and polyolefin can be cited. These fibers can be single-spun fibers or mixed-spun fibers. As other substrates, paper, release paper, plastic films of polyester and polyolefin, metal plates such as aluminum, glass plates, etc. can be cited.

[0234] The curable composition of the present embodiment can be coated by commonly used methods. Examples of coating methods include, for example, a knife coater, a roll blade coater, a reverse roll coater, a roll squeegee coater, an intaglio roll coater, a kiss roll coater, etc.

[0235] The obtained synthetic leather can be used directly. Alternatively, for the purpose of further imparting various properties, the synthetic leather is obtained by coating a polymer solution or emulsion of a polyurethane resin, a vinyl chloride, a cellulose-based resin, etc. on the synthetic leather. In addition, the synthetic leather can also be obtained in the form of a laminate obtained by laminating the above polymer solution or emulsion coated on a release paper, drying the resulting film, and then peeling off the release paper.

[0236] Hereinafter, the present embodiment will be described with reference to the drawings. The drawings and manufacturing conditions described below are one mode of the present embodiment, and the present embodiment is not limited thereto.

[0237] Figure 1 is through Figure 2 A schematic cross-sectional view of a synthetic leather laminate manufactured by the dry method shown. In the structure of this laminate, an epidermal layer 2 is provided on a substrate (a knitted fabric formed of polyester fibers) 4 with a bonding layer 3 interposed therebetween. A release paper 1 used in manufacturing is attached to the outermost layer, but it is peeled off during use.

[0238] Figure 2 It is a schematic diagram showing one of the manufacturing methods of a dry synthetic leather laminate sheet using the curable composition of the present embodiment. In this manufacturing method, first, a resin for the epidermal layer (synthesis example) adjusted to a predetermined temperature in advance is cast onto a release paper 1 (usually with a leather-like pattern) by a coater 5.

[0239] The coater and the resin for the epidermal layer are usually adjusted to a temperature of 20 to 80°C, preferably adjusted to 30 to 70°C, and more preferably adjusted to 40 to 60°C. By setting the temperature of the coater and the epidermal layer resin to 20°C or higher, there is a tendency to suppress the resin viscosity, stabilize the flow rate, and prevent coating unevenness. In addition, by setting the temperature of the coater and the resin for the epidermal layer to 80°C or lower, there is a tendency to prevent the volatilization of the solvent used as a diluent and to easily obtain a uniform thickness of the epidermal layer.

[0240] Thereafter, after forming a sheet of a predetermined thickness by a coating roll 8, it is passed through a dryer 11 to cure and dry the non-reactive organic solvent, thereby forming the epidermal layer 2 of the synthetic leather. The temperature of the dryer is usually set to 60 to 150°C, preferably set to 70 to 130°C, and more preferably set to 80 to 110°C. The drying time is usually 2 minutes to 15 minutes, preferably 3 minutes to 10 minutes, and more preferably 4 minutes to 7 minutes.

[0241] The resin for the skin layer is not particularly limited. In addition to being adjusted by the method shown in the synthesis examples, commercially available products can also be used. Without particular limitation, examples include the "CRISVON" series manufactured by DIC Corporation and the "RESAMINE" series manufactured by Dainichi Kasei Kogyo Co., Ltd.

[0242] Next, each raw material of the curable composition of the present embodiment preliminarily adjusted to a specified temperature is mixed using a mixing head 6, and the curable composition thus obtained is cast to form an adhesive layer 3.

[0243] When the one-step method is applied to the manufacture of the adhesive layer, the main agent (component (a), component (b), component (c), component (d), and component (g) as required), the curing agent (component (e)), the non-reactive organic solvent as required, and the additives are continuously fed into the mixing head 6 separately or simultaneously and mixed, and then cast on the skin layer.

[0244] When the prepolymer method is applied to the manufacture of the adhesive layer, the prepolymer composition (one or more kinds) and the other raw materials (component (a), component (b), component (c), component (d), and component (g) as required), the non-reactive organic solvent as required, and the additives are continuously fed into the mixing head 6 separately or simultaneously and mixed, and then cast on the skin layer. By using this curable composition for the adhesive layer, a synthetic leather having excellent physical property balance of good low-temperature characteristics, flexibility (touch), chemical resistance, and heat resistance can be obtained, and a synthetic leather using less solvent or no solvent at all can be obtained.

[0245] Each component before mixing is usually adjusted to a temperature of 20 to 60°C, preferably adjusted to 30 to 50°C, and more preferably adjusted to 35 to 45°C. In addition, the temperature of the mixing head 6 is usually also adjusted to a temperature of 20 to 60°C, preferably adjusted to 30 to 50°C, and more preferably adjusted to 35 to 45°C. By making the temperature of each component before mixing and the temperature of the mixing head 6 20°C or higher, there is a tendency to suppress the viscosity of the raw materials used, especially the polycarbonate polyol, and to stabilize the flow rate. In addition, by making the temperature of each component before mixing and the temperature of the mixing head 6 60°C or lower, there is a tendency to moderately control the curing rate of the curable composition of the present embodiment, suppress the sharp increase in the viscosity of the curable composition, and obtain a uniform thickness of the synthetic leather.

[0246] Thereafter, after forming a sheet of a predetermined thickness by the coating roll 8, it is passed through the dryer 11 for curing and drying of the non-reactive organic solvent to form the adhesive layer 3 of the synthetic leather. Next, the substrate 4 and the adhesive layer 3 are overlapped and crimped by the crimping roll 9 to obtain the sheet structure 7, which is wound up by the winding roll 10 to obtain the desired synthetic leather laminate. The temperature of the dryer 11 is usually set to 50 to 140 °C, preferably set to 60 to 130 °C, and more preferably set to 80 to 120 °C. The drying time is usually 2 minutes to 15 minutes, preferably 3 minutes to 12 minutes, and more preferably 4 minutes to 10 minutes.

[0247] Figure 2 The manufacturing example of the synthetic leather including the three layers of the epidermis layer / adhesive layer / substrate is shown. By increasing the thickness of the adhesive layer to make it function as an intermediate layer, a quasi-four-layer structure of the epidermis layer / adhesive layer and intermediate layer / substrate is formed. Of course, an intermediate layer can also be used separately to form, for example, a structure of epidermis layer / adhesive layer / intermediate layer / adhesive layer / substrate. The adhesiveness between the epidermis layer and the substrate is controlled by adjusting the curing state of the curable composition. Specifically, it can be obtained by crimping the curable composition of the present embodiment with the substrate in an incompletely cured state. A cured product can be obtained by controlling the temperature and time. As an example, the curing temperature of the dryer 11 is set to 50 to 140 °C, preferably set to 60 to 130 °C, and more preferably set to 80 to 120 °C. The drying time is usually set to 2 minutes to 15 minutes, preferably set to 3 minutes to 12 minutes, and more preferably set to 4 minutes to 10 minutes.

[0248] <Use>

[0249] The synthetic leather obtained using the curable composition of the present embodiment can be used for automotive interior materials such as automotive sheets, furniture uses such as sofas, clothing uses, shoe uses, bag uses, other general merchandise, etc.

[0250] Examples

[0251] Hereinafter, examples and comparative examples are listed to more specifically illustrate the present invention, but the present invention is not limited to these examples as long as it does not exceed its gist. In the following examples and comparative examples, the analysis and evaluation methods of the physical properties of each component are as follows.

[0252] [Analysis and Evaluation of Polycarbonate Polyol]

[0253] <Hydroxyl Value of Polycarbonate Polyol>

[0254] It is measured according to JIS K1557-1.

[0255] <Composition (Copolymerization Ratio) of Polycarbonate Polyol>

[0256] Weigh 1 g of the polycarbonate polyol sample into a 100 mL eggplant-shaped flask, add 30 g of ethanol and 4 g of potassium hydroxide, and react at 100 °C for 1 hour. After cooling the reaction solution to room temperature, add 2 - 3 drops of phenolphthalein as an indicator and neutralize with hydrochloric acid. After cooling in the refrigerator for 1 hour, filter to remove the precipitated salt, and analyze using a gas chromatograph (GC). The GC analysis is carried out as follows: Use a gas chromatograph GC-14B (manufactured by Shimadzu Corporation, Japan) equipped with DB-WAX (manufactured by J&W Company, USA) as the column, use diethylene glycol diethyl ether as the internal standard, and use a flame ionization detector (FID) as the detector to perform quantitative analysis of each component. It should be noted that the temperature rising curve of the column is: maintain at 60 °C for 5 minutes, and then rise to 250 °C at a rate of 10 °C / min.

[0257] Based on the molar ratio of each alcohol component detected from the above analysis results, calculate the composition (copolymerization ratio) of the polycarbonate polyol.

[0258] <Average functionality number of polycarbonate polyol>

[0259] Set the average functionality number of the polycarbonate polyol synthesized using only diol monomers as raw materials to 2. When polyfunctional monomers are included as raw materials, the average functionality number is calculated through the following operations. Through gel permeation chromatography (GPC) analysis (refer to the following for the GPC device and analysis conditions) using a standard polystyrene with a known molecular weight to prepare a standard curve, calculate the number average molecular weight (Mn) of the polycarbonate polyol. Based on the hydroxyl value analyzed separately and the number average molecular weight (Mn) obtained through GPC, use Equation (5) to calculate the average functionality number (n) per molecule.

[0260] Average functionality number (n) = [Mn] × ([OH value] × 10 -3 / 56.1) (5)

[0261] (GPC device and analysis conditions)

[0262] GPC device: HLC-8320 manufactured by Tosoh Corporation

[0263] Column: 1 piece of TSKgel G4000H

[0264] 1 piece of G3000H

[0265] 2 pieces of G2000H

[0266] Eluent: Tetrahydrofuran (THF)

[0267] Flow rate: 1.0 mL / min

[0268] Column temperature: 40 °C

[0269] RI detector: RI (built-in in device HLC - 8320)

[0270] <Measurement of melt viscosity>

[0271] After preheating the polycarbonate polyol to 50 °C, use an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TVE - 22HT, cone: No. 6) to measure the melt viscosity at 50 °C.

[0272] [Analysis and evaluation of prepolymer composition]

[0273] <Measurement of melt viscosity>

[0274] After preheating the prepolymer composition to 50 °C, use an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TVE - 22HT, cone: No. 6) to measure the melt viscosity at 50 °C under a nitrogen atmosphere.

[0275] <Measurement of isocyanate group concentration>

[0276] Dilute 10 mL of the dibutylamine / toluene (mass ratio: 25.85 / 865) mixed solution with 10 mL of dimethylformamide (DMF), then titrate with a 0.1 N hydrochloric acid propanol solution to measure the amount of hydrochloric acid propanol required for neutralization as the blank value. Then, take out 2 g of the prepolymer solution, add 10 mL of the dibutylamine / toluene mixed solution, stir at room temperature for 30 minutes, then dilute with 10 mL of DMF in the same way as the blank determination, and titrate with a 0.1 N hydrochloric acid propanol solution to measure the amount of hydrochloric acid propanol solution required for neutralization, and quantify the remaining amine amount. Calculate the concentration of the isocyanate group according to the volume of the hydrochloric acid propanol solution required for neutralization and using the following formula (6).

[0277] Isocyanate group concentration (mass %) =

[0278] (V1 - V2)×f×42×100 / (W×1000) (6)

[0279] V1: Amount of 0.1 N hydrochloric acid propanol solution required for blank determination (mL)

[0280] V2: Amount of 0.1 N hydrochloric acid propanol solution required for this determination (mL)

[0281] W: Sample used for this determination (g)

[0282] f: Factor of hydrochloric acid propanol solution

[0283] [Analysis and evaluation of polyurethane film]

[0284] <Production of Polyurethane Film>

[0285] Each component of the curable composition of the present invention preheated to 40 °C was added in a nitrogen atmosphere in an amount of 80 g based on the curable composition to a 200 mL separable four-necked flask equipped with stirring blades (4 paddle-type blades inclined at 45 degrees). After stirring at 40 °C for 5 minutes, using a spreader, it was coated on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) with a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm, dried on a hot plate with a surface temperature of 60 °C for 2 hours, and then dried in an oven at 100 °C for 12 hours. Furthermore, it was allowed to stand for 12 hours or more under constant temperature and humidity of 23 °C and 55% RH to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties.

[0286] <Flexibility of Polyurethane Film>

[0287] The flexibility of the polyurethane film was evaluated by 5 inspectors, and the touch feeling when touching the film by hand was evaluated. The evaluation criteria are as follows.

[0288] ○ indicates soft, and the evaluation results of the 5 inspectors are consistent.

[0289] △ indicates slightly hard, and the evaluation results of the 5 inspectors are consistent.

[0290] × indicates hard, and the evaluation results of the 5 inspectors are consistent.

[0291] <Appearance of Polyurethane Film>

[0292] According to the following criteria, the surface appearance of the above-produced polyurethane film was visually judged.

[0293] ○ indicates a smooth surface.

[0294] △ indicates that a few streaks are observed along the moving direction of the spreader on the surface.

[0295] × indicates that a large number of streaks are observed along the moving direction of the spreader on the surface.

[0296] <Determination of Molecular Weight>

[0297] A part of the above polyurethane film was cut out, and an N,N-dimethylacetamide solution was prepared so that the concentration of polyurethane became 0.1% by mass. Using a GPC device [manufactured by Tosoh Corporation, product name "HLC-8320" (column: Tskgel SuperHM-H · 4 pieces)], and using a solution obtained by dissolving 2.6 g of lithium bromide in 1 L of dimethylacetamide as the eluent, the number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of standard polystyrene were measured.

[0298] <Evaluation of oil and acid resistance>

[0299] Cut out test pieces of 3 cm × 3 cm from the polyurethane film. After measuring the mass of the test pieces using a precision balance, put them into a glass bottle with a capacity of 250 mL containing 50 mL of oleic acid as the test solvent, and leave them standing in a constant temperature bath under a nitrogen atmosphere at 80 °C for 16 hours. After the test, take out the test pieces, gently wipe the front and back with a paper wipe, then measure the mass using a precision balance, and calculate the mass change rate (increase rate) compared with before the test. The closer the mass change rate is to 0%, the better the oil and acid resistance.

[0300] <Evaluation of ethanol resistance>

[0301] After making a urethane film by the same method as the above <Evaluation of oil and acid resistance>, cut out test pieces of the urethane film to 3 cm × 3 cm. After measuring the mass of the test pieces using a precision balance, put them into a glass petri dish with an inner diameter of 10 cmφ containing 50 mL of ethanol as the test solvent, and immerse them at room temperature of about 23 °C for 1 hour. After the test, take out the test pieces, gently wipe them with a paper wipe, then measure the mass using a precision balance, and calculate the mass change rate (increase rate) compared with before the test. The closer the mass change rate is to 0%, the better the ethanol resistance.

[0302] <Measurement of glass transition temperature (Tg)>

[0303] Cut out test pieces with a width of 10 mm, a length of 40 mm, and a thickness of 0.4 mm from the polyurethane film. Use a viscoelasticity measuring device (manufactured by Hitachi High-Tech Corporation, [TA7000 series, DMA7100]), set the test pieces in such a way that the distance between the chucks is 20 mm, and measure the viscoelasticity while heating from -100 °C to 100 °C at a rate of 5 °C / minute. Read the peak of tanδ and obtain the glass transition temperature (Tg).

[0304] <Tensile test at room temperature (23 °C)>

[0305] According to JIS K6301 (2010), for a long strip-shaped polyurethane test piece made with a width of 10 mm, a length of 100 mm, and a thickness of about 0.5 mm, use a tensile testing machine (manufactured by ORIENTEC Corporation, product name “TENSILON, model: RTE-1210”), and conduct a tensile test at a temperature of 23 °C (relative humidity of 55%) under the conditions that the distance between the chucks is 20 mm and the tensile speed is 100 mm / minute, and measure the stress, breaking point strength, and breaking point elongation when the test piece elongates by 100%.

[0306] <Low-temperature tensile test>

[0307] According to JIS K6301(2010), a polyurethane test piece in the shape of a long strip with a width of 10 mm, a length of 100 mm, and a thickness of about 0.5 mm was prepared. The film was set in a tensile testing machine (manufactured by ORIENTEC, product name "TENSILON, model: RTE - 1210") with a constant temperature bath (manufactured by ORIENTEC, "model: TLF - R3T - E - W") at a chuck - to - chuck distance of 20 mm. Then, after standing at - 20°C for 5 minutes, a tensile test was carried out at a tensile speed of 100 mm / minute, and the stress at 100% elongation of the test piece was measured.

[0308] <Evaluation of heat resistance>

[0309] The polyurethane film was made into a long strip with a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm, and heated in a gear oven at a temperature of 120°C for 1000 hours. For the heated sample, the breaking strength was measured in the same way as the above <Room - temperature tensile test>, and the retention rate (%) was calculated.

[0310] <Evaluation of hydrolysis resistance>

[0311] The polyurethane film was made into a long strip with a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm, and heated in a constant temperature and humidity chamber at a temperature of 70°C and a relative humidity of 95% for 400 hours. For the heated sample, the breaking strength was measured in the same way as the above <Room - temperature tensile test>, and the retention rate (%) was calculated.

[0312] <Amount of solvent>

[0313] From the perspective of reducing the environmental burden, it is preferable that the amount of solvent used in the production of the urethane film is small. The judgment is made according to the following evaluation criteria.

[0314] ◎ indicates that the amount of solvent in the curable composition is in the range of 0% or more and less than 20%.

[0315] 〇 indicates that the amount of solvent in the curable composition is in the range of 20% or more and less than 40%.

[0316] △ indicates that the amount of solvent in the curable composition is in the range of 40% or more and less than 60%.

[0317] × indicates that the amount of solvent in the curable composition is 60% or more.

[0318] [Analysis and evaluation of synthetic leather]

[0319] <Softness of synthetic leather>

[0320] The softness of the synthetic leather was evaluated by 5 inspectors, who felt the touch of the synthetic leather by hand. The evaluation criteria are as follows.

[0321] ○ indicates soft, and the evaluation results of the 5 inspectors are consistent.

[0322] △ indicates slightly hard, and the evaluation results of the 5 inspectors are consistent.

[0323] × indicates hard, and the evaluation results of the 5 inspectors are consistent.

[0324] <Abrasion resistance of synthetic leather>

[0325] A load of 9.8 N was applied to the friction part covered with cotton cloth to abrade the surface of the synthetic leather. The friction part was abraded back and forth 10,000 times on the surface of the synthetic leather at a speed of 60 reciprocations per minute for a period of 140 mm. Observe the abraded synthetic leather and make a judgment according to the following criteria.

[0326] ○ indicates that the resin layer has no cracks or damage.

[0327] △ indicates that the resin layer has cracks.

[0328] × indicates that the resin layer is damaged.

[0329] <Low-temperature storage stability of synthetic leather>

[0330] The synthetic leather was wound around a paper tube with a diameter of 10 cm and stored in a constant-temperature bath at -20°C for 1 month. The synthetic leather was removed from the paper tube and placed in a constant-temperature chamber at 23°C and 50% humidity for 1 day, and the surface was visually observed and judged according to the following criteria.

[0331] ○ indicates that there are no cracks or wrinkles at all.

[0332] △ indicates that there are minute cracks or wrinkles less than 1 mm observed.

[0333] × indicates that there are cracks or wrinkles more than 1 mm observed.

[0334] <Low-temperature bendability of synthetic leather>

[0335] The synthetic leather was made into a strip with a width of 20 mm and a length of 50 mm. Using a De Mattia bending test machine (manufactured by Yasuda Seiki Seisakusho Co., Ltd.), a low-temperature bending test was carried out 30,000 times at a temperature of -10°C, a distance between chucks of 30 mm, a stroke of 15 mm, and a speed of 100 times per minute. Take out the test piece, visually observe the surface, and evaluate according to the following criteria.

[0336] ○ indicates that there are no cracks or wrinkles at all.

[0337] △ indicates the case where minute cracks and wrinkles less than 1 mm are observed.

[0338] × indicates the case where cracks and wrinkles exceeding 1 mm are observed, or the case where peeling between the base fabric and the adhesive layer is observed.

[0339] <Evaluation Method of Adhesiveness (Peel Strength)>

[0340] Scratches are made in advance at the interface between the polyester base fabric of the synthetic leather and the polyurethane resin layer. The separated urethane resin layer and the base fabric are fixed respectively with chucks, and at a temperature of 23°C and a speed of 200 mm / minute, in accordance with JIS K6854-2, using a tensile testing machine (manufactured by ORIENTEC Co., Ltd., model: TENSILON RTE-1210), the peel strength between the polyurethane layer and the base fabric is measured to evaluate the adhesiveness.

[0341] <Chemical Resistance of Synthetic Leather>

[0342] The synthetic leather is made into strips with a width of 20 mm and a length of 50 mm. 0.2 mL of oleic acid is dropped onto the epidermis layer and left standing for 30 minutes. After the test, the surface is wiped with a paper wipe, and the appearance is confirmed and judged according to the following criteria.

[0343] 〇 indicates the case where the embossing and the texture of the synthetic leather have not changed.

[0344] △ indicates the case where the embossing becomes thinner, swelling is observed in the synthetic leather, and a change in the texture of the synthetic leather is observed.

[0345] × indicates the case where the embossing disappears and the adhesive layer peels off.

[0346] <Damp Heat Resistance of Synthetic Leather>

[0347] The synthetic leather is made into strips with a width of 10 mm and a length of 50 mm. It is heated in a thermostatic and humidistatic chamber at a temperature of 90°C and a relative humidity of 95% for 400 hours. The heated sample is taken out, and the visual observation and touch of the surface are confirmed and judged according to the following criteria.

[0348] 〇 indicates the case where the embossing and the texture of the synthetic leather have not changed.

[0349] △ indicates the case where the embossing becomes thinner and a change in the texture of the synthetic leather is observed.

[0350] × indicates the case where the embossing disappears and the adhesive layer peels off.

[0351] [Polycarbonate Polyol Polymerization Example 1]

[0352] Into a 2 L glass flask equipped with a distillation column filled with structured packing and a stirring device, 423 g (4.8 mol) of ethylene carbonate, 250 g (2.4 mol) of 1,5-pentanediol, and 284 g (2.4 mol) of 1,6-hexanediol were charged. 0.09 g of titanium tetrabutoxide was added as a catalyst, the reaction temperature was set to 140 - 160 °C, while reducing the pressure from 10 kPa to 2 kPa and distilling off the mixture of ethylene glycol and ethylene carbonate formed, the reaction was carried out for 12 hours.

[0353] Thereafter, single distillation was switched, while slowly reducing the pressure to 0.5 kPa, the reaction was carried out at 180 °C for 5 hours to distill out the monomer. The analysis results of the obtained polycarbonate diol (also denoted as PC1) are shown in Table 1.

[0354] [Polymerization Example 2 of Polycarbonate Polyol]

[0355] Using the same apparatus as in Polymerization Example 1 above, 423 g (4.8 mol) of ethylene carbonate, 216 g (2.4 mol) of 1,4-butanediol, and 284 g (2.4 mol) of 1,6-hexanediol were used, and 0.09 g of titanium tetrabutoxide was used as a catalyst. Except for this, polymerization was carried out in the same manner as in Polymerization Example 1. The analysis results of the obtained polycarbonate polyol (also denoted as PC2) are shown in Table 1.

[0356] [Polymerization Example 3 of Polycarbonate Polyol]

[0357] The polymerization time after switching to single distillation was set to 1 hour. Except for this, polymerization was carried out in the same manner as in Polymerization Example 1. The analysis results of the obtained polycarbonate polyol (also denoted as PC3) are shown in Table 1.

[0358] [Polymerization Example 4 of Polycarbonate Polyol]

[0359] The polymerization time after switching to single distillation was set to 1.5 hours. Except for this, polymerization was carried out in the same manner as in Polymerization Example 1. The analysis results of the obtained polycarbonate polyol (also denoted as PC4) are shown in Table 1.

[0360] [Polymerization Example 5 of Polycarbonate Polyol]

[0361] Into a 2 L glass flask equipped with a distillation column filled with structured packing and a stirring device, 423 g (4.8 mol) of ethylene carbonate, 229 g (2.2 mol) of 1,5-pentanediol, 236 g (2.0 mol) of 1,6-hexanediol, 122 g (0.7 mol) of 1,10-decanediol, and 0.09 g of titanium tetrabutoxide as a catalyst were charged. Except for this, polymerization was carried out in the same manner as in Polymerization Example 1. The analysis results of the obtained polycarbonate polyol (also denoted as PC5) are shown in Table 1.

[0362] [Polycarbonate Polyol Polymerization Example 6]

[0363] Using the same apparatus as in Polymerization Example 1 above, 423 g (4.8 mol) of ethylene carbonate was used, 507 g (4.3 mol) of 3-methyl-1,5-pentanediol was used, 59 g (0.5 mol) of 1,6-hexanediol was used, and 0.09 g of titanium tetrabutoxide was used as a catalyst. Except for this, polymerization was carried out in the same manner as in Polymerization Example 1. The analysis results of the obtained polycarbonate polyol (also denoted as PC6) are shown in Table 1.

[0364] [Polycarbonate Polyol Polymerization Example 7]

[0365] 423 g (4.8 mol) of ethylene carbonate, 567 g (4.8 mol) of 1,6-hexanediol, and 0.09 g of titanium tetrabutoxide as a catalyst were put into a 2 L glass flask equipped with a rectifying column filled with structured packing and a stirring device. Except for this, polymerization was carried out in the same manner as in Polymerization Example 1. The analysis results of the obtained polycarbonate polyol (also denoted as PC7) are shown in Table 1.

[0366] [Polycarbonate Polyol Polymerization Example 8]

[0367] The polymerization time after switching to single distillation was set to 3 hours. Except for this, polymerization was carried out in the same manner as in Polymerization Example 1. The analysis results of the obtained polycarbonate polyol (also denoted as PC8) are shown in Table 1.

[0368] [Polycarbonate Polyol Polymerization Example 9]

[0369] The polymerization time after switching to single distillation was set to 10 hours. Except for this, polymerization was carried out in the same manner as in Polymerization Example 1. The analysis results of the obtained polycarbonate polyol (also denoted as PC9) are shown in Table 1.

[0370] [Table 1]

[0371]

[0372] [Synthesis Example 1 of Prepolymer Composition]

[0373] 30 g (0.12 mol) of MDI was put into a 500 mL separable flask sealed with nitrogen and heated to 50 °C. While stirring, 120 g of polycarbonate polyol PC1 (0.06 mol) added with 120 g of methyl ethyl ketone (MEK) heated to 50 °C and 0.007 g of dibutyltin dilaurate as a catalyst was added dropwise over 30 minutes. The reaction was carried out at 50 °C with stirring for 2 hours to obtain a prepolymer composition with isocyanate groups at both ends. The analysis results of the obtained prepolymer composition (also denoted as PCP1) are shown in Table 2.

[0374] [Synthesis Examples 2 - 14 of Prepolymer Compositions]

[0375] The amounts of the polycarbonate polyol, MDI, and MEK used were set to the amounts shown in Table 2. Otherwise, the prepolymer composition was synthesized in the same manner as in Synthesis Example 1 of the prepolymer composition. The analysis results of the obtained prepolymer compositions (also denoted as PCP2 - PCP14 respectively) are shown in Table 2.

[0376] [Table 2]

[0377]

[0378] [Example 1]

[0379] 10 g of polycarbonate polyol PC1, 10 g of polycarbonate polyol PC3, 7 g of polyester polyol PEs1, 7 g of polyether polyol PE1, 10 g of MDI pre - dissolved at 80°C, 8.1 g of methyl ethyl ketone (MEK), and 0.003 g of dibutyltin dilaurate as a catalyst, which had been pre - heated to 60°C, were put into a 200 - mL separable flask with a stirring blade sealed with nitrogen. After stirring at 60°C for 3 minutes, using a spreader, it was coated on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) with a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm, dried on a hot plate with a surface temperature of 60°C for 2 hours, and then dried in an oven at 100°C for 12 hours. Furthermore, it was left standing for more than 12 hours at a constant temperature and humidity of 23°C and 55% RH to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties. The evaluation results are shown in Table 3.

[0380] [Examples 2 - 15]

[0381] The types and amounts of the raw materials were set to the types and amounts described in Table 3. Otherwise, the same operations as in Example 1 were performed to obtain a polyurethane film. The evaluation results of the obtained polyurethane film are shown in Table 3.

[0382] [Comparative Examples 1 - 5]

[0383] The types and amounts of the raw materials were set to the types and amounts described in Table 3. Otherwise, the same operations as in Example 1 were performed to obtain a polyurethane film. The evaluation results of the obtained polyurethane film are shown in Table 3.

[0384] [Table 3]

[0385]

[0386] PEs1: Kuraray Polyol P-2010 (polyester polyol, hydroxyl value 56.2 mg KOH / g, functionality 2.0, manufactured by Kuraray Co., Ltd.)

[0387] PEs2: polyester polyol, hydroxyl value 62.6 mg KOH / g, functionality 2.0

[0388] [Polymerization Example of Polyester Polyol]

[0389] 584 g (4.0 mol) of adipic acid and 567 g (4.8 mol) of 3-methyl-1,5-pentanediol were charged into a 2 L glass flask purged with nitrogen and equipped with a stirring device. 0.02 g of titanium tetrabutoxide was added as a catalyst, and the reaction temperature was set to 190 - 220 °C. The reaction was carried out while distilling off the generated water under atmospheric pressure. Sampling was carried out appropriately, and the reaction was stopped when the target hydroxyl value was reached to obtain PEs2.

[0390] PEs3: Kuraray Polyol P-1010 (polyester polyol, hydroxyl value 112 mg KOH / g, functionality 2.0, manufactured by Kuraray Co., Ltd.)

[0391] PEs4: Kuraray Polyol P-3010 (polyester polyol, hydroxyl value 37.3 mg KOH / g, functionality 2.0, manufactured by Kuraray Co., Ltd.)

[0392] PE1: PTMG2000 (polyether polyol, hydroxyl value 56.4 mg KOH / g, functionality 2.0, manufactured by Mitsubishi Chemical Corporation)

[0393] PE2: PTMG-1800 (polyether polyol, hydroxyl value 63.2 mg KOH / g, functionality 2.0, manufactured by Asahi Kasei Corporation)

[0394] PE3: PTMG1000 (polyether polyol, hydroxyl value 112 mg KOH / g, functionality 2.0, manufactured by Mitsubishi Chemical Corporation)

[0395] PE4: PTMG3000 (polyether polyol, hydroxyl value 38.0 mg KOH / g, functionality 2.0, manufactured by Mitsubishi Chemical Corporation)

[0396] CE1: 1,4-butanediol (manufactured by Mitsubishi Chemical Corporation, chain extender)

[0397] [Urethane Solution for Epidermal Layer: Surface Layer Synthesis Example 1]

[0398] 60 g of polycarbonate polyol PC1 preheated to 60 °C, 6 g of polyester polyol PEs1, 12 g of hydrogenated MDI, 300 g of methyl ethyl ketone (MEK), and 0.003 g of dibutyltin dilaurate as a catalyst were charged into a 500 mL separable flask sealed with nitrogen and equipped with a stirring blade. After stirring at 60 °C for 30 minutes, 1 g of chain extender CE1 was added, the temperature was set to 80 °C, and stirring was continued. The reaction was continued until an increase in viscosity was observed, and 1 g of ethanol was added to stop the reaction, obtaining a urethane solution for the skin layer.

[0399] [Example 16]

[0400] 100 g of prepolymer composition PCP1 preheated to 50 °C, 35 g of polycarbonate polyol, 15 g of polyester polyol PEs1, and 15 g of polyether polyol PE1 were charged into a 200 mL separable flask sealed with nitrogen and equipped with a stirring blade. After stirring at 50 °C for 5 minutes, using a spreader, it was coated on a polypropylene resin sheet (width 100 mm, length 1200 mm, thickness 1 mm) with a width of 80 mm, a length of 100 mm, and a thickness of 0.6 mm, dried on a hot plate with a surface temperature of 60 °C for 2 hours, and then dried in an oven at 100 °C for 12 hours. Furthermore, it was left standing at 23 °C and 55% RH in a constant temperature and humidity environment for more than 12 hours to obtain a polyurethane film. The obtained polyurethane film was subjected to evaluation of various physical properties. The evaluation results are shown in Table 4.

[0401] [Examples 17 - 20]

[0402] The types and amounts of the prepolymer composition and polycarbonate polyol were set to the types and amounts described in Table 4. Except for this, the same operations as in Example 16 were carried out to obtain a polyurethane film. In addition, in the prepolymer component and / or polyol, component (a), component (b), component (c), component (d), and optionally component (g) were included. The evaluation results of the obtained polyurethane film are shown in Table 4.

[0403] [Comparative Example 6]

[0404] The types and amounts of the prepolymer composition and polycarbonate polyol were set to the types and amounts described in Table 4. Except for this, the same operations as in Example 16 were carried out to obtain a polyurethane film. The evaluation results of the obtained polyurethane film are shown in Table 4.

[0405] [Table 4]

[0406]

[0407] [Example 21]

[0408] Using the same as Figure 2The same device as the shown device is used. A release paper with an embossed pattern (manufactured by LINTEC Corporation, R-86M) is used. A solution obtained by dispersing 5 parts by mass of a black pigment in 100 parts by mass of the resin for the skin layer synthesized in Synthesis Example 1 and allowing it to stand overnight is ejected from a coater and continuously cast onto the release paper. The thickness is adjusted to 50 μm using a coating roll. It is passed through a dryer at 120 °C to form a urethane layer that becomes the skin layer.

[0409] Next, in the same manner as in Example 1 in terms of composition ratio, the raw materials used in Example 1 are continuously mixed in a mixing head at a temperature of 40 °C, continuously cast onto the release paper, and the thickness is adjusted to 250 μm using a coating roll. It is passed through a dryer at 120 °C to form a urethane layer that becomes the adhesive layer.

[0410] Next, it is pasted with a base cloth having a thickness of 600 μm (a woven fabric made of polyester fibers) using a crimping roll, wound using a winding roll, and cured at 50 °C for 1 week. The release paper is removed to obtain synthetic leather formed of a laminate of polyurethanes. The physical property evaluation results of the synthetic leather are shown in Table 5.

[0411] [Examples 22 to 37]

[0412] The type of the curable composition that becomes the adhesive layer is set to the composition shown in Table 5. Except for this, the same operations as in Example 21 are performed to obtain synthetic leather formed of a laminate of polyurethanes. The obtained synthetic leather is evaluated, and the results are shown in Table 5.

[0413] [Comparative Examples 7 to 12]

[0414] The type of the curable composition that becomes the adhesive layer is set to the composition shown in Table 5. Except for this, the same operations as in Example 20 are performed to obtain synthetic leather formed of a laminate of polyurethanes. The obtained synthetic leather is evaluated, and the results are shown in Table 5.

[0415] [Table 5]

[0416]

[0417] Industrial Applicability

[0418] The curable composition of the present invention can be used for environment-friendly synthetic leather having excellent physical property balance of softness, chemical resistance, low-temperature characteristics, heat resistance, and touch and using less solvent.

Claims

1. A curable composition comprising: Component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, Component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, Component (c): a polyether polyol, Component (d): a polyester polyol, and Component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6, The total amount of Component (a) and Component (b) is 30% to 70% by mass relative to the total amount of all polyol components in the composition.

2. The curable composition according to claim 1, comprising Component (f): an isocyanate group-terminated prepolymer containing units derived from one or more polyols selected from the group consisting of Component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, Component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, Component (c): a polyether polyol, Component (d): a polyester polyol, and units derived from Component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6.

3. A curable composition comprising: Component (f): an isocyanate group-terminated prepolymer having units derived from one or more polyols selected from the group consisting of Component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, Component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, Component (c): a polyether polyol, Component (d): a polyester polyol, and units derived from Component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6 as structural units; and All components among Component (a), Component (b), Component (c), and Component (d) that are not included in the structural units of Component (f), The total amount of the units derived from Component (a) and the units derived from Component (b) in the structural units of Component (f) and the total amount of Component (a) and Component (b) is 30% to 70% by mass relative to the total amount of all polyol components in the composition.

4. A curable composition comprising: Component (h): a hydroxyl group-terminated prepolymer containing units derived from one or more polyols selected from the group consisting of Component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, Component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, Component (c): a polyether polyol, Component (d): a polyester polyol, and units derived from Component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6; All components among Component (a), Component (b), Component (c), and Component (d) that are not included in the structural units of Component (h); and Component (e), The total amount of the units derived from component (a) and the units derived from component (b) in the structural unit of component (h) and the total amount of component (a) and component (b) are 30% to 70% by mass relative to the total amount of all polyol components in the composition.

5. A curable composition, comprising: Component (f): an isocyanate group-terminated prepolymer, which has units derived from one or more polyols selected from the group consisting of component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, component (c): a polyether polyol, and component (d): a polyester polyol, and units derived from component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6 as structural units; Component (h): a hydroxyl group-terminated prepolymer, which contains units derived from one or more polyols selected from the group consisting of component (a): a polycarbonate polyol having a hydroxyl value of 40 to 75 mgKOH / g, component (b): a polycarbonate polyol having a hydroxyl value of 100 to 280 mgKOH / g, component (c): a polyether polyol, and component (d): a polyester polyol, and units derived from component (e): a polyisocyanate having an average number of functional groups per molecule of 2 to 6; And All components among component (a), component (b), component (c), and component (d) that are not included in the structural units of component (f) and component (h); and Optionally contains component (e), The total amount of the units derived from component (a) and the units derived from component (b) in the structural unit of component (f) and the total amount of the units derived from component (a) and the units derived from component (b) in the structural unit of component (h) and the total amount of component (a) and component (b) are 30% to 70% by mass relative to the total amount of all polyol components in the composition.

6. The curable composition according to any one of claims 1 to 5, wherein, The polycarbonate polyols of component (a) and component (b) contain repeating units represented by the following formula (1) and terminal hydroxyl groups, In formula (1), R1 is a divalent aliphatic hydrocarbon group or a divalent alicyclic hydrocarbon group having 2 to 15 carbon atoms.

7. The curable composition according to claim 6, wherein, More than 50 mol% of the repeating units represented by formula (1) contain at least two repeating units selected from formula (2), formula (3), and formula (4), 8. The curable composition according to any one of claims 1 to 5, which contains component (g): a chain extender.

9. The curable composition according to any one of claims 1 to 5, wherein, The hydroxyl value of component (c): the polyether polyol and the hydroxyl value of component (d): the polyester polyol are each 40 to 75 mgKOH / g.

10. The curable composition according to any one of claims 1 to 5, which contains an inactive organic solvent of 40% by mass or less relative to the total amount of the composition.

11. The curable composition according to any one of claims 1 to 5, which is used for an adhesive layer for synthetic leather.

12. A synthetic leather, which is made from the curable composition according to any one of claims 1 to 11.

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