Polyol composition

Abstract

A polyol composition. The object of the present invention is to provide a polyol composition that can be used as a raw material, for example, in the manufacture of synthetic leather under solvent-free conditions, and a method for manufacturing synthetic leather under solvent-free conditions. In addition, the object of the present invention is to provide a polyol composition that can, for example, obtain a polyurethane film excellent in flexibility, chemical resistance, and resistance to heat and humidity, and serves as a raw material in the manufacture of synthetic leather under solvent-free conditions. A polyol composition for use as a raw material in the manufacture of synthetic leather under solvent-free conditions, which has a carbonate skeleton, and the viscosity of the polyol composition measured at 50 °C by the method of JIS K 1557-5 (2007) is 100 to 1250 mPa·s, and the hydroxyl value measured by the method of JIS K 1557-1 (2007) is 40 to 75 mgKOH / g.

Description

Technical Field

[0001] The present invention relates to a polyol composition. Background Art

[0002] Synthetic leather made from urethane resin is widely used in the manufacture of vehicle interior materials, furniture, moisture-permeable waterproof clothing, etc. Among them, urethane resin using polycarbonate diol is known as an excellent raw material with hydrolysis resistance, chemical resistance, oxidation degradation resistance, heat resistance, etc. As the urethane resin, an N,N-dimethylformamide (hereinafter abbreviated as "DMF") solution of polyurethane is usually used. However, the use of DMF is becoming more and more regulated in Europe and China, and it has become an urgent task to shift to a reduction in its usage and a solvent-free state.

[0003] As a method for solving this problem, the following surface material forming composition for a fiber laminate is known, in which the main agent is a polycarbonate diol obtained from 1,6-hexanediol and a low molecular carbonate, and the curing agent contains a modified polyisocyanate of hexamethylene diisocyanate and an isocyanurate-modified polyisocyanate, and neither the main agent nor the curing agent contains an organic solvent (for example, refer to Patent Document 1). In addition, as a solvent-free method, a method for manufacturing synthetic leather having a cured product layer of a moisture-curable urethane hot-melt resin composition is known (for example, refer to Patent Document 2). In addition, in the use of ultrafine fiber nonwoven synthetic leather, the following polyurethane dispersion is known, which contains: a polyurethane prepolymer containing an aromatic diisocyanate and a polyether polyol, and an anionic surfactant (for example, refer to Patent Document 3).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: International Publication No. 2009-098841

[0007] Patent Document 2: Japanese Patent No. 6485726

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 2019-529614 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] However, the polycarbonate diol obtained from 1,6 - hexanediol and a low - molecular - weight carbonate used in Patent Document 1 has a high viscosity. Therefore, the viscosity of the liquid obtained by blending the main agent and the curing agent is high, and it may not be possible to coat the release support. Even if it can be coated, there are problems with the surface smoothness of the resulting coating film. In addition, in the method described in Patent Document 2, the viscosity of the urethane resin becomes high, and when the resin composition is coated on a substrate, there is a problem that the resulting coating film does not form a uniform thickness. Moreover, in the methods described in the patent documents, there are problems with the chemical resistance and abrasion resistance of the resulting synthetic leather.

[0011] Therefore, an object of the present invention is to provide a polyol composition that can be used as a raw material, for example, when manufacturing synthetic leather under solvent - free conditions, and a method for manufacturing synthetic leather under solvent - free conditions. In addition, an object of the present invention is to provide a polyol composition that can obtain a polyurethane film excellent in flexibility, chemical resistance, and heat and humidity resistance, and that becomes a raw material when manufacturing synthetic leather under solvent - free conditions.

[0012] Solutions for Solving the Problems

[0013] The inventor of the present invention repeatedly conducted in - depth research to solve the above - mentioned problems, and as a result, found that a polyol composition satisfying specified characteristics can solve the above - mentioned problems, thereby completing the present invention.

[0014] That is, the present invention is as follows.

[0015] 〔1〕A polyol composition for use as a raw material in the manufacture of synthetic leather under solvent - free conditions, which has a carbonate skeleton,

[0016] The viscosity of the polyol composition measured at 50 °C by the method of JIS K 1557 - 5(2007) is 100 - 1250 mPa·s, and the hydroxyl value measured by the method of JIS K 1557 - 1(2007) is 40 - 75 mgKOH / g.

[0017] 〔2〕The polyol composition according to 〔1〕, which has an ester skeleton and / or an ether skeleton, and the content of the carbonate skeleton is 1 - 99 mol%.

[0018] 〔3〕The polyol composition according to 〔1〕, which has an ester skeleton and / or an ether skeleton, and the content of the carbonate skeleton is 1 - 30 mol%.

[0019] 〔4〕The polyol composition according to any one of 〔1〕 to 〔3〕, the glass transition temperature measured by a differential scanning calorimeter is - 60 °C or lower, and the acid value determined by the method shown in JIS K 0070(1992) is 2.5 mgKOH / g or lower.

[0020] 〔5〕A urethane prepolymer for producing synthetic leather under solvent-free conditions, which is obtained by using the polyol composition described in any one of 〔1〕to 〔4〕and a polyisocyanate.

[0021] 〔6〕A method for producing synthetic leather, which comprises the following steps: coating a urethane prepolymer composition containing the urethane prepolymer described in 〔5〕on a base fabric or a release support under solvent-free conditions and subjecting it to moisture curing.

[0022] 〔7〕A method for producing synthetic leather, which comprises the following steps: coating a mixed solution obtained by mixing a urethane prepolymer composition containing the urethane prepolymer described in 〔5〕with a crosslinking agent on a base fabric or a peelable support under solvent-free conditions and subjecting it to reaction.

[0023] Effects of the Invention

[0024] The polyol composition of the present invention can be used as a raw material, for example, when producing synthetic leather under solvent-free conditions. In addition, the polyol composition of the present invention can obtain a polyurethane film having excellent flexibility, chemical resistance, and heat and humidity resistance, and can be used as a raw material when producing synthetic leather under solvent-free conditions. Detailed Description of the Invention

[0025] Hereinafter, the present detailed description (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 the gist thereof.

[0026] [Polyol Composition]

[0027] The polyol composition of the present embodiment is a polyol composition used as a raw material when producing synthetic leather under solvent-free conditions (hereinafter also referred to as "polyol composition for producing synthetic leather under solvent-free conditions"), which has a carbonate skeleton and a viscosity of 100 to 1250 mPa·s measured at 50 °C by the method of JIS K 1557-5 (2007), and a hydroxyl value of 40 to 75 mgKOH / g measured by the method of JIS K 1557-1 (2007). The polyol composition of the present invention can obtain a polyurethane film having excellent flexibility, chemical resistance, and heat and humidity resistance.

[0028] The polyol composition of the present embodiment preferably contains a polyol having a carbonate skeleton (hereinafter also abbreviated as "carbonate skeleton") represented by the following formula (A) and a terminal hydroxyl group.

[0029]

[0030] Furthermore, the polyol composition of the present embodiment may have an ester skeleton and / or an ether skeleton together with a carbonate skeleton. In this case, the content of the carbonate skeleton evaluated by the method described in the examples below is preferably 1 to 99 mol%. If the content of the carbonate skeleton is 1 mol% or more, chemical resistance and hydrolysis resistance of the resulting synthetic leather or artificial leather can be expected. On the other hand, if the content of the carbonate skeleton is 99 mol% or less, the viscosity of the polyol composition at 50°C can be set within the above range by optimizing the composition of the polyol composition. If the content of the carbonate skeleton is 5 mol% or more, it is more preferable. If it is 10 mol% or more, it has chemical resistance and hydrolysis resistance that can be used even in applications requiring high durability such as in-vehicle applications, so it is further preferable. The content of the carbonate skeleton is more preferably 90 mol% or less, further preferably 80% or less, still further preferably 70% or less. If it is 60% or less, it is particularly preferable. If it is 30% or less, it is extremely preferable.

[0031] The viscosity of the polyol composition of the present embodiment measured by the method of JIS K 1557-5 (2007) at 50°C is 100 to 1250 mPa·s. If the viscosity of the polyol composition is 100 mPa·s or more, when the resulting polyurethane resin composition is coated on a base fabric or a release paper, a desired thickness can be obtained. On the other hand, if the viscosity of the polyol composition is 1250 mPa·s or less, the polyurethane composition obtained from the polyol composition can be coated on a base fabric or a peelable support without using a solvent. If the viscosity of the polyol composition is 100 to 1200 mPa·s, it is further preferable. If the viscosity of the polyol composition is 100 to 1000 mPa·s, there is a tendency that a synthetic leather having a target thickness can be obtained from the polyurethane composition obtained from the polyol composition without using a solvent regardless of the molecular weight of the polyurethane.

[0032] As a method for controlling the viscosity of the polyol composition within the above range, there is no particular limitation, and examples thereof include a method of selecting a diol used as a raw material in the production of polycarbonate diol. Generally, there is a tendency that as the main chain of the diol becomes longer or the diol has a side chain, the viscosity of the resulting polycarbonate diol becomes lower. Furthermore, a method of selecting the structure and amount of the combined ester compound and / or ether compound can be cited.

[0033] It should be noted that in the present embodiment, the viscosity of the polyol composition can be measured by the method described in the examples below.

[0034] The hydroxyl value of the polyol composition of the present embodiment, measured by the method shown in JIS K 1557-1 (2007), is preferably 40 to 75 mgKOH / g. If the hydroxyl value of the polyol composition of the present embodiment is 40 mgKOH / g or more, there is a tendency that the polyurethane composition obtained from the polyol composition can be coated on the base fabric and the release support without using a solvent. If the hydroxyl value of the polyol composition of the present embodiment is 75 mgKOH / g or more, there is a tendency that a soft synthetic leather or artificial leather can be obtained. If the hydroxyl value of the polyol composition of the present embodiment is 45 to 70 mgKOH / g, it is more preferable. If it is 45 to 65 mgKOH / g, it is further preferable.

[0035] As a method for controlling the hydroxyl value of the polyol composition within the above range, there is no particular limitation. For example, in the method of mixing a polycarbonate diol with an ether compound and / or an ester compound, a method of mixing so that the mass average of the hydroxyl values of the polycarbonate diol and the ether compound and / or the ester compound reaches the above range can be cited. In addition, when an ether compound and / or an ester compound is used as a raw material to polymerize a polycarbonate diol, a method of polymerizing until the hydroxyl value reaches the above range can be cited.

[0036] It should be noted that in the present embodiment, the hydroxyl value of the polyol composition can be measured by the method described in the following examples.

[0037] It is generally known that if the hydroxyl value of the polyol composition is increased, the viscosity of the polyol composition becomes low, and the softness of the synthetic leather using this polyol composition is reduced. The polyol composition of the present embodiment has a low viscosity without increasing the hydroxyl value, so that when manufacturing a synthetic leather, the amount of solvent can be reduced, and thus solvent-free can be achieved, and a synthetic leather with softness can be obtained.

[0038] It is required that the synthetic leather used in in-vehicle applications and the like does not reduce its softness even at low temperatures below -20°C. In order to obtain such a synthetic leather, it is preferable that the glass transition temperature (hereinafter also referred to as "Tg") of the polyol composition used as a raw material is low. The Tg of the polyol composition of the present embodiment, measured by a differential scanning calorimeter, is preferably -50°C or lower. If the Tg is -50°C or lower, the synthetic leather obtained using the polyol composition has a tendency that the reduction in softness is small even at low temperatures below -20°C. If the Tg of the polyol composition of the present embodiment is -55°C or lower, it is further preferable. If the Tg is -60°C or lower, regardless of the composition of the polyurethane, the change in softness at low temperatures becomes smaller, so it is further preferable. The lower limit of the Tg of the polyol composition of the present embodiment is not particularly limited, for example, it is -90°C.

[0039] As a method for controlling the Tg of the polyol composition within the aforementioned range, there is no particular limitation, and examples thereof include a method of selecting the diol used as a raw material in the production of polycarbonate diol, and a method of controlling the structure and the amount thereof of the ester compound and / or ether compound combined with the polycarbonate diol.

[0040] It should be noted that in the present embodiment, the Tg of the polyol composition is evaluated by the method described in the examples below.

[0041] Generally, compared with the Tg of the polyol composition, the Tg of the polyurethane obtained from the polyol composition becomes higher (hereinafter, the difference between the Tg of the polyurethane and the Tg of the polyol composition is also referred to as ΔTg). ΔTg varies depending on the type of the polyol composition, the composition of the urethane, etc., but when ΔTg is present, there is a tendency that the change in the softness of the synthetic leather at normal temperature and low temperature becomes smaller. In the polyol composition of the present embodiment, MDI is used as the isocyanate, 1,4-butanediol is used as the chain extender, and ΔTg evaluated by the method described in the examples below is preferably 50°C or lower, and more preferably 45°C or lower if it is 45°C or lower. The lower limit of ΔTg is not particularly limited, and is, for example, 1°C.

[0042] As a method for controlling ΔTg within the aforementioned range, there is no particular limitation, and examples thereof include a method of controlling the structure and the amount thereof of the ester compound and / or ether compound combined with the polycarbonate diol.

[0043] The polyol composition of the present embodiment preferably has fluidity at room temperature (20 ± 5°C). "Having fluidity at room temperature" mentioned in this specification means that the flow time evaluated by the method described in the examples below is within 90 seconds. This flow time is preferably within 70 seconds, and more preferably within 50 seconds. When the flow time of the polyol composition of the present embodiment is within 90 seconds, it is also not necessary to heat and dissolve, and it is easy to handle. Furthermore, there is a tendency that the softness of the obtained polyurethane also becomes higher, and thus it is preferred.

[0044] If the polyol composition of the present embodiment has fluidity at room temperature, there is no particular problem even if it is turbid.

[0045] The acid value of the polyol composition of the present embodiment is preferably 2.5 mgKOH / g or less. If the acid value of the polyol composition of the present embodiment is 2.5 mgKOH / g or less, there is a tendency that the hindrance to the action of the catalyst used in the urethane reaction is small. If the acid value is 1.5 mgKOH / g or less, it is more preferably. The lower limit of the acid value of the polyol composition of the present embodiment is not particularly limited, and is, for example, 0.05 mgKOH / g.

[0046] As a method for controlling the acid value of the polyol composition within the aforementioned range, there is no particular limitation, and examples thereof include a method of adding an acidic compound or a basic compound to the polyol composition.

[0047] It should be noted that in the present embodiment, the acid value of the polyol composition is evaluated by the method described in the following examples.

[0048] The polyol composition of the present embodiment preferably contains polycarbonate diol. The method for obtaining a polyol composition having an ether skeleton and / or an ester skeleton is not limited, and examples thereof include a method of mixing polycarbonate diol with an ether compound and / or an ester compound; a method of adding an ether compound and / or an ester compound to polycarbonate diol and heating and stirring at 130 to 180 °C for reaction; a method of polymerizing polycarbonate diol using an ether compound and / or an ester compound as a raw material.

[0049] The method for producing the polycarbonate diol used in the polyol composition of the present embodiment is not particularly limited, and it can be produced by various methods described in, for example, Polymer Reviews, Volume 9, p9 - 20 (1994) written by Schnell. For example, it can be produced using a diol and a carbonate as raw materials.

[0050] The aforementioned diol is not particularly limited, and examples thereof include diols without side chains such as ethylene glycol, 1,3 - propanediol, 1,4 - butanediol, 1,5 - pentanediol, 1,6 - hexanediol, 1,7 - heptanediol, 1,8 - octanediol, 1,9 - nonanediol, 1,10 - decanediol, 1,11 - undecanediol, 1,12 - dodecanediol, 1,13 - tridecanediol, 1,14 - tetradecanediol, 1,15 - pentadecanediol; diols with side chains such as 2 - methyl - 1,8 - octanediol, 2 - ethyl - 1,6 - hexanediol, 2 - methyl - 1,3 - propanediol, 3 - methyl - 1,5 - pentanediol, 2,4 - dimethyl - 1,5 - pentanediol, 2,4 - diethyl - 1,5 - pentanediol, 2 - butyl - 2 - ethyl - 1,3 - propanediol, 2,2 - dimethyl - 1,3 - propanediol; cyclic diols such as 1,4 - cyclohexanedimethanol and 2 - bis(4 - hydroxycyclohexyl)propane. These diols can be used alone or in combination of two or more. Among these, if one or more diols without side chains are used as raw materials, the chemical resistance and mechanical strength are further improved, so it is preferred. In addition, it is preferred to use two or more (preferably two) diols selected from the group consisting of 1,3 - propanediol, 1,4 - butanediol, 1,5 - pentanediol, and 1,6 - hexanediol as raw materials for the polycarbonate diol.

[0051] In the production of the polycarbonate diol used in the present embodiment, when two or more diols are used as raw materials, the ratio of these raw materials is not particularly limited. In order to make the obtained polyol composition have fluidity at room temperature, it is preferable to set the raw material ratio. More specifically, when two diols are used as raw materials, it is preferable to set the feeding amount so that the molar ratio reaches 20 / 80 to 80 / 20. If the molar ratio is within the above range, the obtained polycarbonate diol tends to be in a liquid state at 20°C. The molar ratio is more preferably 30 / 70 to 70 / 30, and further preferably 40 / 60 to 60 / 40.

[0052] The aforementioned carbonate is not particularly limited, and examples thereof 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. These carbonates can be used alone or in combination of two or more. Among these, from the viewpoints of easy availability and easy setting of conditions during the polymerization reaction, it is preferable to use at least one selected from the group consisting of dimethyl carbonate, diethyl carbonate, diphenyl carbonate, dibutyl carbonate, and ethylene carbonate.

[0053] In the production of the polycarbonate diol used in this embodiment, it is preferable to add a catalyst. The aforementioned catalyst is not particularly limited, and generally, catalysts used in transesterification reactions (transesterification catalysts) can be cited. The transesterification catalyst is not particularly limited, and examples thereof include metal compounds of alkali metals and alkaline earth metals (for example, organometallic compounds such as metal alkoxides (metal alkyl oxides), metal oxides, and metal amides; inorganic metal compounds such as metal hydrides and metal hydroxides; metal salts such as metal carbonates, nitrogen-containing metal borates, and basic alkali metal salts and alkaline earth metal salts of organic acids). The alkali metal is not particularly limited, and examples thereof include lithium, sodium, and potassium. The alkaline earth metal is not particularly limited, and examples thereof include magnesium, calcium, strontium, and barium. Other metals are not particularly limited, and examples thereof include aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, indium, tin, antimony, tungsten, rhenium, osmium, iridium, platinum, gold, thallium, lead, bismuth, and ytterbium. These catalysts can be used alone or in combination of two or more. Among these, if at least one metal organic compound (especially metal alkoxide) and / or salt selected from the group consisting of sodium, potassium, magnesium, potassium, titanium, zirconium, tin, lead, and ytterbium is used, the polymerization reaction of the polycarbonate diol proceeds well, and when using the obtained polycarbonate diol to produce resins such as polyurethane resins, it is not likely to cause an impact, so it is preferable. In particular, as the aforementioned catalyst, it is more preferable to use an organic compound (especially metal alkoxide) and / or salt of at least one metal selected from the group consisting of titanium, tin, zirconium, magnesium, and ytterbium.

[0054] Specific examples of the method for producing the polycarbonate diol used in this embodiment are shown below. The production of the polycarbonate diol used in this embodiment is not particularly limited. For example, it can be carried out in two stages. The diol and the carbonate are mixed in a ratio of, for example, 20:1 to 1:10 in terms of molar ratio (diol:carbonate), and the first-stage reaction is carried out at 100 to 250 °C under normal pressure or reduced pressure. When using dimethyl carbonate as the carbonate, the generated methanol can be removed in the form of a mixture with dimethyl carbonate to obtain a low-molecular-weight polycarbonate diol. When using diethyl carbonate as the carbonate, the generated ethanol can be removed in the form of a mixture with diethyl carbonate to obtain a low-molecular-weight polycarbonate diol. In addition, when using ethylene carbonate as the carbonate, the generated ethylene glycol can be removed in the form of a mixture with ethylene carbonate to obtain a low-molecular-weight polycarbonate diol. Then, the second-stage reaction is as follows: the reaction product of the first stage is heated at 160 to 250 °C under reduced pressure to remove unreacted diol and carbonate, and the low-molecular-weight polycarbonate diol is condensed to obtain a polycarbonate diol with a specified molecular weight.

[0055] The ether compound used in the polyol composition of the present embodiment is not particularly limited, and examples thereof include polyether polyols obtained by adding one or more alkylene oxides such as ethylene oxide and propylene oxide to one or more polyhydroxy compounds (e.g., ethylene glycol, propylene glycol, trimethylolpropane, glycerin, pentaerythritol); ring-opening polymers such as tetrahydrofuran; ethers having two or more OH groups such as diethylene glycol and triethylene glycol.

[0056] The ester compound used in the polyol composition of the present embodiment is not particularly limited, and examples thereof include polyester polyols obtained by direct esterification reaction and / or transesterification reaction of a polyol with a polycarboxylic acid or its ester, anhydride, acyl halide and other ester-forming derivatives. The above polyol is not particularly limited, and examples thereof include aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, diethylene glycol, and triethylene glycol; alicyclic diols such as cyclohexanedimethanol and cyclohexanediol; alcohols having three or more hydroxyl groups such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, pentaerythritol, and tetramethylolpropane. The above polycarboxylic acid or its ester-forming derivative is not particularly limited, and examples thereof include aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 2-methylsuccinic acid, 2-methyladipic acid, 3-methyladipic acid, 3-methylglutaric acid, 2-methyloctanedioic acid, 3,8-dimethyldecanedioic acid, 3,7-dimethyldecanedioic acid, hydrogenated dimer acid, and dimer acid; aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; alicyclic dicarboxylic acids such as 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-dicarboxymethylcyclohexane, nadic acid, and methylnadic acid; polycarboxylic acids such as tricarboxylic acids such as trimellitic acid, pyromellitic acid, and trimer of castor oil fatty acid; acid anhydrides of these polycarboxylic acids, acyl halides such as chlorides and bromides of the polycarboxylic acids, and methyl esters, ethyl esters, propyl esters, isopropyl esters, butyl esters, and isobutyl esters of the polycarboxylic acids. Further, ring-opening polymers of caprolactone such as polycaprolactone diol can be cited.

[0057] [Urethane prepolymer]

[0058] The urethane prepolymer of this embodiment is a urethane prepolymer for manufacturing synthetic leather under solvent-free conditions, and is obtained by using the above polyol composition and polyisocyanate.

[0059] The urethane prepolymer can be obtained by combining a polyol composition, a polyisocyanate, and a chain extender as needed. Further, as needed, additives such as a urethanization catalyst, a silane coupling agent, a thixotropy imparting agent, an antioxidant, a plasticizer, a filler, and wax can be used alone or in combination of two or more.

[0060] There is no particular limitation on the polyisocyanate, and for example, aromatic polyisocyanates such as phenylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, and carbodiimidized diphenylmethane polyisocyanate can be used; aliphatic or alicyclic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, dimer acid diisocyanate, and norbornene diisocyanate can be used. These polyisocyanates can be used alone or in combination of two or more.

[0061] There is no particular limitation on the aforementioned chain extender, and for example, chain extenders having an amino group such as ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophorone diamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4'-dicyclohexylmethane diamine, 3,3'-dimethyl-4,4'-dicyclohexylmethane diamine, and hydrazine can be used; chain extenders having a hydroxyl group such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, sucrose, methylene glycol, glycerol, sorbitol, bisphenol A, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, and trimethylolpropane can be used. These chain extenders can be used alone or in combination of two or more.

[0062] Specifically, the urethane prepolymer of this embodiment can be manufactured by, for example, using the above polyol composition, polyisocyanate, and chain extender as needed, and reacting under the condition that the isocyanate groups in the polyisocyanate are in excess relative to the hydroxyl groups in the polyol composition and the like.

[0063] [Method for manufacturing synthetic leather]

[0064] The manufacturing method of the synthetic leather of the present embodiment may be a method including a step of coating a urethane prepolymer composition containing the above-mentioned urethane prepolymer on a base fabric or a release support under solvent-free conditions and subjecting it to moisture curing, or may be a method including a step of coating a mixed solution obtained by mixing a urethane prepolymer composition containing the above-mentioned urethane prepolymer with a crosslinking agent on a base fabric or a releasable support under solvent-free conditions and subjecting it to reaction.

[0065] Specifically, the manufacturing method of the synthetic leather of the present embodiment is not particularly limited, and examples thereof may include a method of preparing the above-mentioned urethane prepolymer having an isocyanate group and subjecting it to moisture curing; a method of curing by mixing the above-mentioned urethane prepolymer with a crosslinking agent having a hydroxyl group and / or an amino group.

[0066] More specifically, examples may include a method of forming a cured product layer on a base material (base fabric) by coating the above-mentioned urethane prepolymer on a release support, then laminating the coated surface to the base material (base fabric) and subjecting it to curing; a method of forming a cured product layer on the base material by directly coating the above-mentioned urethane prepolymer on the base material (base fabric) and subjecting it to curing, and the like.

[0067] As the aforementioned base material (base fabric), for example, non-woven fabrics, knitted fabrics, woven fabrics based on polyester fibers, polyethylene fibers, nylon fibers, acrylic fibers, polyurethane fibers, acetate fibers, rayon fibers, polylactic acid fibers, cotton, hemp, silk, wool, glass fibers, carbon fibers, their blended fibers, etc.; substances obtained by impregnating the aforementioned non-woven fabrics with resins such as polyurethane resins; substances obtained by further providing a porous layer on the aforementioned non-woven fabrics; resin substrates such as thermoplastic urethane (TPU), etc. can be used.

[0068] As a method of coating the urethane prepolymer, it is not particularly limited, and examples thereof may include methods using an applicator, a roll coater, a spray coater, a T-die coater, a doctor blade coater, a comma coater, etc.

[0069] As the aforementioned crosslinking agent, examples may include crosslinking agents having a hydroxyl group such as polyether polyol, polycarbonate polyol, polyester polyol, polyacrylic polyol, dimer diol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, sucrose, methylene glycol, glycerol, sorbitol, bisphenol A, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, trimethylolpropane; crosslinking agents having an amino group such as ethylenediamine, tetramethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, hydrazine, piperazine, diaminodiphenylmethane, toluenediamine, xylylenediamine, isophoronediamine, norbornanediamine, etc.

[0070] It should be noted that in this embodiment, "solvent-free" means manufacturing a urethane prepolymer without using a solvent and manufacturing synthetic leather without adding a solvent thereto. Furthermore, it also includes the following cases: not using DMF which has been used in the past, and furthermore, reducing the amount of the solvent to less than half, and furthermore, to less than 1 / 3 of the amount used in the past. In addition, in this embodiment, artificial leather is also included in the category of synthetic leather.

[0071] Examples

[0072] Hereinafter, specific examples and comparative examples will be listed to explain this embodiment in more detail. However, as long as it does not exceed the gist thereof, this embodiment is not limited to the following examples and comparative examples at all.

[0073] Various physical properties in the examples and comparative examples described below are measured by the methods shown below.

[0074] 1. Viscosity of polyol composition

[0075] Except for setting the measurement temperature at 50°C, the viscosity of the polyol composition is determined by the method using a cone-plate rotational viscometer shown in JIS K 1557-5 (2007).

[0076] 2. Determination of hydroxyl value of polyol composition

[0077] The hydroxyl value of the polyol composition is determined by Method A shown in JIS K 1557-1 (2007).

[0078] 3. Determination of acid value of polyol composition

[0079] The acid value of the polyol composition is determined by the potentiometric titration method shown in JIS K 0070 (1992).

[0080] 4. Determination of carbonate backbone value of polyol composition

[0081] The polyol composition is determined as follows 1 The H-NMR integral value ratio is obtained, and the carbonate backbone value of the polyol composition is calculated.

[0082] First, 10 mg of the sample is dissolved in 0.75 mL of deuterated chloroform (manufactured by Aldrich). Tetramethylsilane (TMS) as a chemical shift reference is added to this solution, and for the resulting solution, ECZ500 (SC) manufactured by JEOL Ltd. is used to measure 1 H-NMR. In this measurement, the resonance frequency is set to 500 MHz, the pulse width is set to 45°, the standby time is set to 5 seconds, the number of accumulations is set to 5000 times, and the TMS signal is set to 0 ppm, and 11H-NMR spectrum. In the previously measured 1 1H-NMR spectrum, using the integral values of the signals of methylene and / or methine bonded to the oxygen of the carbonate bond, the signals of methylene and / or methine bonded to the oxygen of the ether bond, and the signals of methylene and / or methine bonded to the carbonyl carbon of the ester bond, the carbonate backbone value of the polyol composition is determined using the following formula (1).

[0083] Carbonate backbone value (mol%) = (A / 2 + B) / {(A / 2 + B) / 2 + (C / 2 + D) / 2 + (E / 2 + F)} × 100 ··· (1)

[0084] A: Integral value of methylene bonded to the oxygen of the carbonate bond

[0085] B: Integral value of methine bonded to the oxygen of the carbonate bond

[0086] C: Integral value of methylene bonded to the oxygen of the ether bond

[0087] D: Integral value of methine bonded to the oxygen of the ether bond

[0088] E: Integral value of methylene bonded to the carbonyl carbon of the ester bond

[0089] F: Integral value of methine bonded to the carbonyl carbon of the ester bond

[0090] 5. Determination of the fluidity of the polyol composition

[0091] Use a flat-bottomed cylindrical transparent glass test tube with an inner diameter of 30 mm and a height of 120 mm, marked with scale lines at heights of 55 mm (A line) and 85 mm (B line) from the bottom of the tube. Measure the sample (polyol composition) heated in a dryer at 50 °C for 8 hours up to the A line, and then let it stand upright at room temperature of 20 ± 5 °C for 24 hours. Then, immediately lay it horizontally on the base, and take the time taken from laying down the test tube until the liquid front of the sample passes the B line as the flow time (seconds), which is set as the fluidity index of the polyol composition. When the flow time is 90 seconds or less, it is evaluated as having fluidity. In addition, during this measurement, it is also confirmed whether the polyol composition is transparent or turbid.

[0092] 6. Determination of the glass transition temperature (Tg) of the polyol composition

[0093] Put the polyol composition into an aluminum dish of about 10 g, and use a differential scanning calorimeter (DSC7000X, manufactured by Hitachi High-Technologies Corporation) to perform the following heating and cooling operations: Heat from 30 °C to 100 °C at a rate of 20 °C per minute under a nitrogen atmosphere, cool from 100 °C to -100 °C at a rate of 5 °C per minute, and heat from -100 °C to 100 °C at a rate of 5 °C per minute. Set the inflection point during the second heating as the glass transition temperature (Tg) of the polyol composition.

[0094] 7. Determination of the difference (ΔTg) in the glass transition temperature (Tg) between the polyurethane and the polyol composition

[0095] Use the polyol composition for which Tg was determined in the above item 6 to manufacture a polyurethane film by the method described below. Cut out test pieces with a width of 10 mm, a length of 40 mm, and a thickness of 0.4 mm from the obtained polyurethane film. Use a viscoelasticity measuring device (manufactured by Hitachi High-Technologies Corporation, [TA7000 series, DMA7100]), set the test piece with a distance between chucks of 20 mm, and perform viscoelasticity measurement while heating from -100 °C to 100 °C at 5 °C per minute. Read the peak of tanδ from the measurement result to obtain the glass transition temperature (Tg) of the polyurethane. Apply the Tg of the polyol composition obtained in the above item 6 and the Tg of the polyurethane using this polyol composition, and determine ΔTg by the following formula (2).

[0096] ΔTg (°C) = (Tg of polyurethane) - (Tg of polyol composition) (2)

[0097] 8. Evaluation of flexibility

[0098] Make short strip test pieces with a width of 10 mm, a length of 100 mm, and a thickness of about 0.1 mm from the polyurethane film manufactured by the method described below. For the manufactured test pieces, use a tensile testing machine (manufactured by ORIENTEC Corporation, product name “TENSILON, model: RTE-1210”), and perform a tensile test under the conditions of a distance between chucks of 20 mm, a tensile speed of 100 mm / minute, and a temperature of 23 °C (relative humidity of 55%), and measure the stress (100% modulus) when the test piece elongates by 100%. The lower the 100% modulus, the better the flexibility is evaluated.

[0099] 9. Evaluation of moisture and heat resistance

[0100] A short strip sample with a width of 10 mm, a length of 100 mm, and a thickness of about 100 μm was made of a polyurethane film. For the prepared sample, using a thermo-hygrostat manufactured by ESPEC Corporation, product name "PL-1J", heating was carried out for 10 days under the conditions of a temperature of 85 °C and a humidity of 85%. For the samples before and after heating, using a tensile testing machine (manufactured by ORIENTEC Corporation, product name "TENSILON, model: RTE-1210"), a tensile test was carried out under the conditions of a distance between chucks of 20 mm, a tensile speed of 100 mm / minute, and a temperature of 23 °C (relative humidity of 55%). The stress at which the test piece broke was measured, and the strength retention rate (%) was calculated using the following formula (3), which was set as an index for the heat and humidity resistance of the polyurethane. The higher the strength retention rate, the more excellent the heat and humidity resistance was evaluated.

[0101] Strength retention rate (%) = breaking strength after heating / breaking strength before heating × 100 (3)

[0102] 10. Chemical resistance test (oil acid resistance test)

[0103] As the chemical resistance, the oil acid resistance was evaluated.

[0104] A test piece of 1 cm × 10 cm was cut out from the polyurethane film. After measuring the mass of the test piece using a precision balance, it was put into a glass tube with a capacity of 250 mL containing 50 mL of oleic acid as a test solvent and left standing in a constant temperature bath under a nitrogen atmosphere at 80 °C for 24 hours. After the test, the test piece was taken out, gently wiped on both sides with a tissue paper, and then the mass was measured using a precision balance to calculate the mass change rate (increase rate (swelling rate (%))) compared with before the test. The closer the mass change rate was to 0%, the better the oil acid resistance was indicated.

[0105] [Polymerization Example 1]

[0106] 680 g (7.6 mol) of dimethyl carbonate, 420 g (4.0 mol) of 1,5-pentanediol, and 480 g (4.1 mol) of 1,6-hexanediol were put into a 2 L glass flask equipped with a distillation column filled with regular fillers and a stirring device. 0.14 g of titanium tetraisopropoxide as a catalyst was further added to the aforementioned flask, and the mixture in the flask was stirred and heated under normal pressure to start the reaction. While raising the temperature to 90 - 140 °C, the mixture of the generated methanol and dimethyl carbonate was distilled off, and the reaction was carried out for 20 hours. Thereafter, the pressure was reduced to 17 kPa, and while distilling off the mixture of methanol and dimethyl carbonate, the reaction was further carried out at 150 °C for 15 hours to obtain a polycarbonate diol (hereinafter also referred to as "PC-1").

[0107] [Polymerization Example 2]

[0108] Polymerization was carried out using the apparatus shown in Polymerization Example 1. 580 g (6.6 mol) of ethylene carbonate, 300 g (3.3 mol) of 1,4-butanediol, and 390 g (3.3 mol) of 1,6-hexanediol were charged. 0.11 g of titanium tetrabutoxide was added as a catalyst, and stirring / heating was carried out under atmospheric pressure. The reaction temperature was slowly raised to 160 °C, and while distilling off the mixture of the produced ethylene glycol and ethylene carbonate, the reaction was carried out for 20 hours. Thereafter, the pressure was reduced to 15 kPa, and while distilling off the diol and ethylene carbonate, the reaction was further carried out at 160 °C for 6 hours to obtain a polycarbonate diol (hereinafter also referred to as "PC-2").

[0109] [Polymerization Example 3]

[0110] Polymerization was carried out using the apparatus shown in Polymerization Example 1. 820 g (7.0 mol) of diethyl carbonate and 860 g (7.3 mol) of 1,6-hexanediol were charged. 0.14 g of titanium tetrabutoxide was added as a catalyst, and stirring was carried out under atmospheric pressure. While raising the temperature to 90 - 160 °C, the mixture of the produced ethanol and diethyl carbonate was distilled off, and the reaction was carried out for 20 hours. Thereafter, the pressure was reduced to 17 kPa, and while distilling off the mixture of ethanol and diethyl carbonate, the reaction was further carried out at 160 °C for 12 hours to obtain a polycarbonate diol (hereinafter also referred to as "PC-3").

[0111] [Comparative Example 1]

[0112] 420 g of the polycarbonate diol P-1 obtained in Polymerization Example 1 and 180 g of polyoxypropylene glycol E-1 (manufactured by Sanyo Chemical Industries, Ltd., "NEWPOL PE-61" (trade name), number average molecular weight: about 2000) were charged into a 1 L glass flask equipped with a stirring device (hereinafter also referred to as "reactor"). Then, they were heated with stirring, and the temperature inside the reactor was maintained at about 145 °C for 15 hours. Then, 2-ethylhexyl acid phosphate was added in a molar ratio of 2.5 times that of titanium tetraisopropoxide, and heat treatment was carried out at a reactor internal temperature of 120 °C for 5 hours to obtain a polyol composition A-21. It should be noted that regarding the transesterification reaction, gel permeation chromatography (hereinafter sometimes abbreviated as "GPC") was measured for the reaction solution over time, and the disappearance of the peaks derived from the raw materials and the appearance of the peaks derived from the products were confirmed over time to confirm the progress of the reaction, etc. And regarding the finally obtained polyol composition, the reaction was carried out substantially quantitatively based on the charged amounts of the raw materials, and the corresponding structure was also confirmed by the GPC measurement over time. The physical properties of the obtained polyol composition A-21 were measured by the above method, and the results are shown in Table 1.

[0113] [Example 1]

[0114] 300 g of the polycarbonate diol P-1 obtained in Polymerization Example 1 and 300 g of polyoxypropylene glycol E-1 (manufactured by Sanyo Chemical Industries, Ltd., "NEWPOL PE-61" (trade name), number average molecular weight: about 2,000) were charged. Except for this, the reaction was carried out by the method of Comparative Example 1 to obtain a polyol composition A-1. The physical properties of the obtained polyol composition A-1 were measured by the above method, and the results are shown in Table 1.

[0115] [Example 2]

[0116] 150 g of the polycarbonate diol P-1 obtained in Polymerization Example 1 and 450 g of polyoxypropylene glycol E-1 (manufactured by Sanyo Chemical Industries, Ltd., "NEWPOL PE-61" (trade name), number average molecular weight: about 2,000) were charged. Except for this, the reaction was carried out by the method of Comparative Example 1 to obtain a polyol composition A-2. The physical properties of the obtained polyol composition A-2 were measured by the above method, and the results are shown in Table 1.

[0117] [Example 3]

[0118] 18 g of the polycarbonate diol P-1 obtained in Polymerization Example 1 and 582 g of polyoxypropylene glycol E-1 (manufactured by Sanyo Chemical Industries, Ltd., "NEWPOL PE-61" (trade name), number average molecular weight: about 2,000) were charged. Except for this, the reaction was carried out by the method of Comparative Example 1 to obtain a polyol composition A-3. The physical properties of the obtained polyol composition A-3 were measured by the above method, and the results are shown in Table 1.

[0119] [Comparative Example 2]

[0120] 6 g of the polycarbonate diol P-1 obtained in Polymerization Example 1 and 594 g of polyoxypropylene glycol E-1 (manufactured by Sanyo Chemical Industries, Ltd., "NEWPOL PE-61" (trade name), number average molecular weight: about 2,000) were charged. Except for this, the reaction was carried out by the method of Example 1 to obtain a polyol composition A-22. The physical properties of the obtained polyol composition A-22 were measured by the above method, and the results are shown in Table 1.

[0121] [Example 4]

[0122] Using the apparatus used in Example 1, 270 g of the polycarbonate diol P-2 obtained in Polymerization Example 2 and 330 g of polyoxypropylene glycol E-1 (manufactured by Sanyo Chemical Industries, Ltd., "NEWPOL PE-61" (trade name), number average molecular weight: about 2000) were charged. Then, while stirring them, they were heated, and the temperature inside the reactor was maintained at about 145 °C for 15 hours. Then, n-butyl acid phosphate was added so as to reach 2.5 times the molar amount relative to titanium tetraisopropoxide, and heat treatment was carried out at a reactor internal temperature of 120 °C for 5 hours, whereby a polyol composition A-4 was obtained. The physical properties of the obtained polyol composition A-4 were measured by the above method, and the results are shown in Table 1.

[0123] [Example 5]

[0124] Using the apparatus used in Example 1, 270 g of the polycarbonate diol P-2 obtained in Polymerization Example 2 and 330 g of polyoxypropylene glycol E-1 (manufactured by Sanyo Chemical Industries, Ltd., "NEWPOL PE-61" (trade name), number average molecular weight: about 2000) were charged. Then, while stirring them, they were heated, and the temperature inside the reactor was maintained at about 80 °C for 30 minutes. Then, n-butyl acid phosphate was added so as to reach 2.5 times the molar amount relative to titanium tetraisopropoxide, and heat treatment was carried out at a reactor internal temperature of 120 °C for 5 hours, whereby a polyol composition A-5 was obtained. The physical properties of the obtained polyol composition A-5 were measured by the above method, and the results are shown in Table 1.

[0125] [Example 6]

[0126] Using the apparatus used in Example 1, 120 g of the polycarbonate diol P-2 obtained in Polymerization Example 2 and 480 g of polytetramethylene glycol E-2 (manufactured by Mitsubishi Chemical Corporation, "PTMG2000" (trade name), number average molecular weight: about 2000) were charged. Then, while stirring them, they were heated, and the temperature inside the reactor was maintained at about 145 °C for 15 hours. Then, n-butyl acid phosphate was added so as to reach 2.5 times the molar amount relative to titanium tetraisopropoxide, and heat treatment was carried out at a reactor internal temperature of 120 °C for 5 hours, whereby a polyol composition A-6 was obtained. The physical properties of the obtained polyol composition A-6 were measured by the above method, and the results are shown in Table 1.

[0127] [Example 7]

[0128] Using the apparatus used in Example 1, 90 g of the polycarbonate diol P-3 obtained in Polymerization Example 3 and 510 g of polycaprolactone diol E-3 (manufactured by Daicel Corporation, "PLACCEL 220" (trade name), number average molecular weight: about 2000) were charged. Then, they were heated with stirring, and the temperature inside the reactor was maintained at about 80°C for 30 minutes. Then, 2-ethylhexyl acid phosphate was added in an amount such that the molar ratio to titanium tetraisopropoxide reached 2.5 times, and heat treatment was carried out at a reactor internal temperature of 120°C for 5 hours to obtain a polyol composition A-7. The physical properties of the obtained polyol composition A-7 were measured by the above method, and the results are shown in Table 1.

[0129] [Table 1]

[0130]

[0131] It should be noted that the abbreviations in the table and in this text are as follows.

[0132] E-1: Polyoxypropylene glycol (manufactured by Sanyo Chemical Industries, Ltd., "NEWPOL PE-61" (trade name), number average molecular weight: about 2000)

[0133] E-2: Polyoxytetramethylene glycol (manufactured by Mitsubishi Chemical Corporation, "PTMG2000" (trade name), number average molecular weight: about 2000)

[0134] E-3: Polycaprolactone diol E-3 (manufactured by Daicel Corporation, "PLACCEL 220" (trade name), number average molecular weight: about 2000)

[0135] [Manufacture of Polyurethane]

[0136] Using the polyol compositions obtained in the use examples and comparative examples, polyurethane films were produced as follows. 38 g of the polyol composition, 224 g of dimethylformamide (hereinafter sometimes abbreviated as DMF), and 0.26 g of a 1% dibutyltin dilaurate toluene solution (50 ppm relative to the total mass of MDI and the polycarbonate diol composition) were placed in a 500 mL separable flask equipped with a thermocouple and a cooling tube, and heated in an oil bath at 40°C. While stirring the solution in the flask at 100 rpm under a nitrogen atmosphere in the flask, 14.8 g of MDI (3.09 times [mol] relative to the OH [mol] of the polycarbonate diol composition) was added dropwise. Furthermore, the solution in the flask was stirred for about 1.5 hours. The isocyanate group concentration was analyzed, and it was confirmed that the theoretical amount was consumed, obtaining a prepolymer. Next, 3.2 g of 1,4-butanediol (1,4-BD) in the necessary amount calculated from the residual isocyanate was added to the flask in portions. After stirring the solution in the flask for about 1 hour, about 1 g of ethanol was added, and further, the solution in the flask was stirred for 30 minutes, obtaining a polyurethane solution.

[0137] Using a 0.8 mm thick applicator, the obtained polyurethane solution was dropped onto the upper part of a glass plate (JIS R3202, 2 mm × 100 mm × 150 mm) and coated so that the dry film thickness reached 50 to 150 μm, and dried on a hot plate at a surface temperature of 60°C for 2 hours, and then dried in an oven at 80°C for 12 hours. Furthermore, it was left standing at 23°C and 55% RH in a constant temperature and humidity environment for 12 hours or more, obtaining a polyurethane film. For the obtained polyurethane film, various physical properties were evaluated by the above method. The evaluation results are shown in Table 2.

[0138] [Table 2]

[0139]

[0140] [Application Example 1 (urethane prepolymer)]

[0141] 300 g of the polyol composition A-1 was placed in a 500 mL separable flask equipped with a thermocouple and a cooling tube, and the pressure was reduced at 50°C to dehydrate until the water content rate reached 0.05 mass% or less. Next, 75 g of MDI was added, and the temperature was raised to 80°C and reacted for about 2 hours until the isocyanate group content rate became constant, obtaining a urethane prepolymer PP-1-1.

[0142] [Application Examples 2 to 7 (urethane prepolymer)]

[0143] Using the polyol compositions A-2 to A-7 instead of the polyol composition A-1, and otherwise using the method of Application Example 1, urethane prepolymers PP-1-2 to PP-1-7 were obtained.

[0144] [Comparative Application Examples 1 and 2 (urethane prepolymers)]

[0145] Using polyol compositions A-21 and A-22 in place of polyol composition A-1, and otherwise following the method of Application Example 1, urethane prepolymers PP-1-21 and PP-1-22 were obtained.

[0146] [Application Example 8 (urethane prepolymer)]

[0147] 300 g of polyol composition A-1 was charged into a 500 mL separable flask equipped with a thermocouple and a cooling tube, and the pressure was reduced at 50 °C to dehydrate until the water content rate reached 0.05 mass% or less. Subsequently, 55 g of MDI was added, and the temperature was raised to 80 °C and allowed to react for about 2 hours until the isocyanate group content rate became constant, obtaining urethane prepolymer PP-2-1.

[0148] [Application Examples 51 to 57 (synthetic leather)]

[0149] 100 parts by mass of urethane prepolymers PP-1-1 to PP-1-7 and 3.6 parts by mass of 1,4-butanediol were mixed, and using a doctor blade coater, it was coated on a release paper so that the dry thickness reached 30 μm, and dried with hot air at 100 °C for 2 minutes. Thereafter, a polyester tricot warp knitted fabric was laminated as a base fabric. After drying at 50 °C for 48 hours, it was peeled off from the release paper to obtain synthetic leather.

[0150] [Comparative Application Examples 11 and 12 (synthetic leather)]

[0151] 100 parts by mass of urethane prepolymers PP-1-21 and PP-1-22 and 3.6 parts by mass of 1,4-butanediol were mixed, and using a doctor blade coater, it was coated on a release paper so that the dry thickness reached 30 μm, and dried with hot air at 100 °C for 2 minutes. Thereafter, a polyester tricot warp knitted fabric was laminated as a base fabric. After drying at 50 °C for 48 hours, it was peeled off from the release paper to obtain synthetic leather.

[0152] [Application Example 61 (synthetic leather)]

[0153] The urethane prepolymer PP-2-1 was heated at 110 °C and coated in an amount of 0.2 kg / m 2 onto a release paper set on a roll coater, and then, while in a sticky state, it was laminated with a non-woven fabric impregnated with a urethane resin, and left in an atmosphere at a temperature of 25 °C and a humidity of 50% RH for 3 days to obtain synthetic leather.

[0154] Industrial Applicability

[0155] The polyol composition of the present invention has a low viscosity. Therefore, it can be used in the polyurethane resin composition used in synthetic leather and artificial leather even without using a solvent. In addition, by using the polyol composition of the present invention, there is a tendency to obtain synthetic leather and artificial leather with excellent chemical resistance and heat and humidity resistance. Therefore, the polyol composition of the present invention can be suitably used in the polyurethane resin composition used in synthetic leather and artificial leather without using a solvent.

Claims

1. A polyol composition for raw materials for manufacturing synthetic leather under solvent-free conditions, which has a carbonate skeleton, and the content of the carbonate skeleton is 1 to 30 mol%, The viscosity of the polyol composition measured at 50 °C by the method of JIS K 1557-5 (2007) is 100 to 1210 mPa·s, and the hydroxyl value measured by the method of JIS K 1557-1 (2007) is 40 to 75 mgKOH / g.

2. The polyol composition according to claim 1, which contains a polyol having a carbonate skeleton and a terminal hydroxyl group represented by the following formula (A), 3. The polyol composition according to claim 1, wherein, The hydroxyl value is 45 to 70 mgKOH / g.

4. The polyol composition according to claim 1, wherein, The hydroxyl value is 45 to 65 mgKOH / g.

5. The polyol composition according to claim 1, which has an ester skeleton and / or an ether skeleton.

6. The polyol composition according to claim 1, wherein, The content of the carbonate skeleton is 10 to 30 mol%.

7. The polyol composition according to any one of claims 1 to 6, the glass transition temperature measured by a differential scanning calorimeter is -60 °C or lower, and the acid value determined by the method described in JIS K 0070 (1992) is 2.5 mgKOH / g or lower.

8. The polyol composition according to claim 7, wherein, The glass transition temperature is -90 °C or higher.

9. The polyol composition according to claim 7, wherein, The acid value is 1.5 mgKOH / g or less.

10. The polyol composition according to claim 7, wherein, The acid value is 0.05 mgKOH / g or more.

11. A urethane prepolymer for manufacturing synthetic leather under solvent-free conditions, which is obtained by using the polyol composition according to any one of claims 1 to 10 and a polyisocyanate.

12. A method for manufacturing synthetic leather, which includes the following steps: coating a urethane prepolymer composition containing the urethane prepolymer according to claim 11 on a base fabric or a release support under solvent-free conditions, and subjecting it to moisture curing.

13. A method for manufacturing synthetic leather, which includes the following steps: coating a mixed solution obtained by mixing a urethane prepolymer composition containing the urethane prepolymer according to claim 11 with a crosslinking agent on a base fabric or a releasable support under solvent-free conditions, and subjecting it to reaction.

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