Polyester polycarbonate polyol and synthetic leather

Abstract

To provide polyester polycarbonate polyol which is a raw material of polyurethane excellent in balance in flexibility (tactile), chemical resistance, low temperature characteristics, heat resistance, hydrolysis resistance, adhesiveness, and abrasion resistance, and a production method of the same.SOLUTION: Polyester polycarbonate polyol has a repeating unit expressed by the following formula (1), a repeating unit expressed by the following formula (2), a molecular terminal of a hydroxyl group, a hydroxyl value of 37-86 mgKOH / g, and a carbonate content of 15-40 mass%. In the formula (1), R1 is a 2-15C bivalent straight chain aliphatic or alicyclic hydrocarbon. In the formula (2), R2 is a 2-15C bivalent hydrocarbon, and R3 is a 2-15C bivalent straight chain aliphatic or alicyclic hydrocarbon.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel polyester polycarbonate polyol and a synthetic leather using the same. [Background technology]

[0002] Conventionally, synthetic leathers with good flexibility have been produced by applying a polyurethane resin solution polymerized using polyether polyols such as polypropylene glycol and polytetramethylene glycol to a fibrous substrate or a film-forming plate and coagulating it in water. While these synthetic leathers offer excellent flexibility, they are susceptible to degradation by components such as sweat and have durability problems. Another type of synthetic leather is produced by coagulating a polyurethane resin solution polymerized using a polyester polyol obtained by reacting a hydroxy compound with a dibasic acid. However, this synthetic leather has problems with hydrolysis resistance.

[0003] As a synthetic leather that solves 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 in which a urethane composition composed of a polyurethane composed of a polycarbonate diol, an organic isocyanate, and a low-molecular-weight diol, and a polyurethane composed of a polyester-based diol, an organic diisocyanate, and a low-molecular-weight diol, is contained in or bonded to a fibrous substrate and / or on the fibrous substrate.

[0004] Patent Document 2 discloses a porous sheet material obtained by a wet film-forming method in which a solution of a polyurethane resin comprising a polymeric diol, an organic isocyanate, and optionally a chain extender is applied to a substrate. The porous sheet material is characterized in that the polymeric diol is a mixed diol of a polycarbonate diol and a polyester diol, the polycarbonate diol is composed of 1,4-butanediol and one or more other alkanediols having 4 to 6 carbon atoms, the diol contains 50 to 90 mol% of 1,4-butanediol based on the total number of moles of the diols, and is a copolymeric polycarbonate diol with a number average molecular weight of 500 to 5,000, and the polyurethane resin has a coagulation value of 7 to 14.

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

[0006] Patent Document 4 discloses a porous sheet material obtained by wet coagulation, which is composed of a polycarbonate diol (a1) made of an alkanediol having 4 to 6 carbon atoms and a polycarbonate diol (a2) made of an alkanediol having 7 to 12 carbon atoms, both of which are copolymer polycarbonate diols, and which is obtained by reacting a polymer diol, an organic isocyanate, and a chain extender, in which the percentage by weight of (a1) to the total weight of (a1) and (a2) is 10% to 80%.

[0007] Patent Document 5 discloses synthetic leather comprising a surface layer formed from a composition for forming a surface layer material for a textile laminate, which is composed of a base agent and a curing agent, wherein the base agent is a polycarbonate diol obtained from 1,6-hexanediol and a low molecular weight carbonate, and the curing agent is a hexamethylene diisocyanate-modified polyisocyanate (B1) having a number average molecular weight of 350 to 500 and an average functionality (f) of 2≦f<3, and an isocyanurate-modified polyisocyanate of hexamethylene diisocyanate (B2) having f≧3, wherein the weight ratio of (B1):(B2) is 50:50 to 95:5, and neither the base agent nor the curing agent contains any organic solvent.

[0008] However, although the synthetic leathers disclosed in Patent Documents 1 to 5 have hydrolysis resistance, they do not have sufficient sweat resistance for applications requiring high durability, such as automobile seats.

[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) to provide a synthetic leather that has an excellent balance of physical properties such as sweat resistance and flexibility and that does not crack or wrinkle during storage. However, the polycarbonate diol described in Patent Document 6 requires the use of a large amount of organic solvent during polyurethane polymerization, and further improvement is desired from the viewpoint of environmental impact.

[0010] Patent Document 7 proposes a polyurethane for synthetic leather that has an excellent balance of physical properties including flexibility, chemical resistance, low-temperature characteristics, heat resistance, and tactile feel. This polyurethane is obtained by reacting at least (a) a compound containing two or more isocyanate groups per molecule, (b) a chain extender, and (c) a polycarbonate diol, wherein the polycarbonate diol (c) has a hydroxyl value of 20 mg-KOH / g to 45 mg-KOH / g, a glass transition temperature measured by a differential scanning calorimeter of −30°C or lower, and a dihydroxy compound obtained by hydrolysis of the polycarbonate diol has an average carbon number of 3 to 5.5. However, the polyurethane for synthetic leather disclosed in Patent Document 7 also requires the use of a large amount of organic solvent during polyurethane polymerization, which is undesirable in terms of environmental impact.

[0011] In recent years, environmentally friendly polyurethanes have been proposed. For example, Patent Document 8 proposes a urethane prepolymer composition that is used by reacting a crosslinking agent with the active hydrogen in the component to increase the molecular weight, and that contains at least 20 to 80 mass% of a hydroxyl-terminated urethane prepolymer with a hydroxyl value of 10 to 100 mg KOH / g, and further contains, as a medium for the polymer, 20 to 80 mass% of an oligomer with a hydroxyl value of 20 to 400 mg KOH / g that has no urethane bonds and is capable of crosslinking with the crosslinking agent, and that is substantially 100% nonvolatile and is liquid at a temperature of at least 30°C. Patent Document 8 also proposes a two-component, solvent-free polyurethane for synthetic leather that contains 90 to 150 equivalent% of a polyisocyanate crosslinking agent with an NCO content of 5 to 35 mass%, based on the average hydroxyl value of the urethane prepolymer composition.

[0012] However, the polyurethane prepolymer composition for synthetic leather disclosed in Patent Document 8 uses an ether-based polyol such as poly-THF or THF-neopentyl glycol copolymer polyol, each having a hydroxyl value of 20 to 400 mgKOH / g, as an oligomer without a urethane bond in order to make it solvent-free, which reduces heat resistance and limits its applications. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Patent No. 3142102 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-119314 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-346094 [Patent Document 4] Patent No. 4177318 [Patent Document 5] Japanese Patent Application Laid-Open No. 2009-185260 [Patent Document 6] Japanese Patent Application Laid-Open No. 2013-108196 [Patent Document 7] Japanese Patent Application Laid-Open No. 2016-8234 [Patent Document 8] Japanese Patent Application Laid-Open No. 2014-105250 Summary of the Invention [Problem to be solved by the invention]

[0014] In view of the above problems, the present invention aims to provide a polyester polycarbonate polyol capable of producing a polyurethane having an excellent balance of physical properties, including flexibility (tactile feel), chemical resistance, hydrolysis resistance, low-temperature characteristics, and heat resistance, and a method for producing the same. [Means for solving the problem]

[0015] As a result of extensive research, the present inventors have found that the use of polyester polycarbonate polyols having a specific structure can provide polyurethanes with an excellent balance of physical properties, including flexibility (tactile feel), chemical resistance, hydrolysis resistance, low-temperature properties, and heat resistance, and can also provide synthetic leathers with an excellent balance of physical properties, such as abrasion resistance and adhesiveness. Furthermore, the present inventors have found that a specific catalyst is useful for producing these polyester polycarbonate polyols, leading to the completion of the present invention.

[0016] That is, the present invention includes the following aspects. [1] A polyester polycarbonate polyol having a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), with hydroxyl groups at the molecular terminals, a hydroxyl value of 37 to 86 mg KOH / g, and a carbonate group content of 15 to 40 mass%. [ka] (In formula (1), R1 is a divalent linear aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.) [ka] (In formula (2), R2 is a divalent hydrocarbon having 2 to 15 carbon atoms, and R3 is a divalent linear aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.) [2] The polyester polycarbonate polyol according to [1], wherein the molar ratio of the structural unit represented by formula (1) to the structural unit represented by formula (2) is 50 / 50 to 95 / 5. [3] The polyester polycarbonate polyol according to [1] or [2], wherein 50 mol % or more of the repeating units represented by formula (1) contain at least two repeating units selected from the group consisting of formulas (3), (4), and (5). [ka] [ka] [ka] [4] The polyester polycarbonate polyol according to [3], wherein 50 mol % or more of the repeating units represented by formula (1) contain repeating units of formula (4) and formula (5). [5] The polyester polycarbonate polyol according to [3], wherein 50 mol % or more of the repeating units represented by formula (1) contain repeating units of formula (3) and formula (5), and the carbonate group content is 21 to 40 mass %. [6] [1] to [5]. Synthetic leather produced using the polyester polycarbonate polyol. [7] [1] or [2], a method for producing a polyester polycarbonate polyol, characterized in that a metal alkoxide is used as a catalyst. [8] The method for producing a polyester polycarbonate polyol according to [7], wherein the metal alkoxide is an alkoxide of a metal of Group 4 of the periodic table. [Effects of the Invention]

[0017] The polyester polycarbonate polyol of the present invention can be used to provide polyurethanes that have an excellent balance of physical properties, including flexibility (tactile feel), chemical resistance, low-temperature characteristics, heat resistance, hydrolysis resistance, abrasion resistance, and adhesiveness, and is suitable for use as a polyol for producing synthetic leather.The present invention also provides a method for producing such polyester polycarbonate polyols. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view of an example of synthetic leather using the polyester polycarbonate polyol of the present invention. [Figure 2]FIG. 1 is a diagram showing an example of a process for producing synthetic leather using the polyester polycarbonate polyol of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention (hereinafter abbreviated as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0020] The polyester polycarbonate polyol of the present embodiment is a polyester polycarbonate polyol having a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), a molecular terminal having a hydroxyl group, a hydroxyl value of 37 to 86 mgKOH / g, and a carbonate group content of 15 to 40 mass%. [ka] (In formula (1), R1 is a divalent linear aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.) [ka] (In formula (2), R2 is a divalent hydrocarbon having 2 to 15 carbon atoms, and R3 is a divalent linear aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.) The polyester polycarbonate polyol of the present embodiment can be cured using a curing agent such as a polyisocyanate to form a polyurethane, which can be used in various molded articles, adhesives, coating agents, and the like.

[0021] <Polyester polycarbonate polyol> The polyester polycarbonate polyol of this embodiment has a hydroxyl value of 37 to 86 mgKOH / g, preferably 45 to 75 mgKOH / g, and more preferably 50 to 65 mgKOH / g. When the hydroxyl value of component (a) is 37 mgKOH / g or more, the strength and chemical resistance of the resulting polyurethane tend to be excellent. Also, when the hydroxyl value of the polyester polycarbonate polyol is 86 mgKOH / g or less, the flexibility (touch) and low-temperature properties of the resulting synthetic leather tend to be improved.

[0022] The polyester polycarbonate polyol preferably has a melt viscosity at 50°C of 1000 to 9000 mPa·s, more preferably 1500 to 8500 mPa·s, and even more preferably 2000 to 7000 mPa·s. When the polyester polycarbonate polyol has a melt viscosity at 50°C of 1000 mPa·s or more, the flexibility and low-temperature properties of the resulting polyurethane tend to be enhanced. Furthermore, when the polyester polycarbonate polyol has a melt viscosity at 50°C of 6000 mPa·s or less, not only does the resulting polyurethane tend to have excellent strength and chemical resistance, but the amount of solvent used in producing the polyurethane can be reduced.

[0023] Hydroxyl groups in one molecule of polyester polycarbonate polyol Number of is preferably 1.7 to 3.5, more preferably 1.8 to 3.0, and even more preferably 2.0 to 2.5. Number of When the ratio is 1.7 or more, the strength, chemical resistance, heat resistance, and hydrolysis resistance of the resulting polyurethane tend to be improved. Number of By ensuring that the value is 3.0 or less, not only is an appropriate curing time obtained during polyurethane production, but the resulting polyurethane also has flexibility.

[0024] The polyester polycarbonate diol of this embodiment has a carbonate group content per molecule of 15 to 40% by mass, more preferably 21 to 40% by mass, even more preferably 25 to 35% by mass, and particularly preferably 25 to 30% by mass. A carbonate group content of 15% by mass or more tends to result in a polyurethane with excellent strength, chemical resistance, abrasion resistance, and hydrolysis resistance. Furthermore, a carbonate group content of 40% by mass or less tends to result in a polyurethane with excellent low-temperature properties and flexibility, and also tends to result in a polyurethane with low viscosity, resulting in a polyurethane with excellent product appearance.

[0025] The carbonate group content is the amount of carbonate groups contained in one molecule of the polyester polycarbonate diol, and is specifically calculated by the following formula (6).

[0026] Carbonate group content (%) = (molecular weight of carbonate group) × (number of carbonate groups per molecule) / (number average molecular weight of polyester polycarbonate polyol) × 100 (6) (Here, the molecular weight of the carbonate group (-OC=OO-) is 60.01.)

[0027] The polyester polycarbonate polyol of this embodiment has a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), and has a hydroxyl group at the molecular terminal. The method for producing the polyester polycarbonate polyol of this embodiment is not particularly limited, but it can be synthesized, for example, by a transesterification reaction described in, for example, "Polymer Reviews, Vol. 9, pp. 9-20," using a bifunctional diol compound (and optionally a trifunctional or higher polyhydric alcohol), a dibasic acid, and a carbonate ester as raw materials. [ka] (In formula (1), R1 is a divalent linear aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.) [ka] (In formula (2), R2 is a divalent hydrocarbon having 2 to 15 carbon atoms, and R3 is a divalent linear aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms.)

[0028] The bifunctional diol compound used in the transesterification reaction is not particularly limited, and examples thereof include diols having a divalent linear aliphatic or alicyclic hydrocarbon skeleton having 2 to 15 carbon atoms. Specific examples of the bifunctional diol compound include 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, 1,3-cyclohexanediol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol. These bifunctional diol compounds may be used alone or in combination of two or more. Among these, from the viewpoint of obtaining a polyurethane excellent in flexibility (touch), chemical resistance, low-temperature properties, and heat resistance, linear alkylene diols having 3 to 9 carbon atoms are preferred, and linear alkylene diols having 4 to 6 carbon atoms are more preferred. It is also preferred to use two or more linear alkylene diols in combination.

[0029] When the carbon number of the bifunctional diol compound is 2 or more, the viscosity of the polyester polycarbonate polyol can be kept low, the amount of organic solvent used can be reduced, and the flexibility and low-temperature properties of the resulting polyurethane tend to be improved.When the carbon number of the bifunctional diol compound is 15 or less, the chemical resistance of the resulting polyurethane tends to be excellent.

[0030] The combined use of two or more bifunctional diol compounds reduces the regularity of the structural units of the resulting polyester polycarbonate polyol, resulting in reduced crystallinity, which not only allows for the production of a liquid polyester polycarbonate polyol at room temperature (25°C), but also tends to increase the flexibility of the polyurethane. Furthermore, when an organic solvent is used in the production of polyurethane, the amount of organic solvent used tends to be reduced. In this embodiment, in addition to the bifunctional diol, a trifunctional or higher polyhydric alcohol compound can be used as the raw material for the polyester polycarbonate polyol, if necessary. The polyhydric alcohol compound is not particularly limited, but examples thereof include trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, glycerin, etc. By using a polyhydric alcohol, the hydroxyl groups in one molecule can be Number of can be easily adjusted to the range of 1.7 to 3.5.

[0031] In this embodiment, it is preferred that 50 mol % or more of the repeating units represented by formula (1) contain at least two repeating units selected from the group consisting of formulas (3), (4), and (5). The content of the repeating units is preferably 70 mol % or more, and more preferably 80 mol % or more.

[0032] [ka] [ka] [ka]

[0033] When at least two repeating units selected from the group consisting of formulas (3), (4), and (5) account for 50 mol % or more of the repeating units represented by formula (1), the resulting polyurethane has excellent flexibility (touch), chemical resistance, low-temperature properties, and heat resistance, and when a solvent is used in producing the polyurethane, the amount of solvent used tends to be reduced. From the same perspective, it is preferable that at least 50 mol % of the repeating units represented by formula (1) contain repeating units of formulas (4) and (5), and it is also preferable that at least 50 mol % of the repeating units represented by formula (1) contain repeating units of formulas (3) and (5), and that the carbonate group content is 21 to 40 mass %.

[0034] In this embodiment, when two types of repeating units are selected from formula (3), formula (4), and formula (5), the molar ratio of the two types of repeating units is 90:10 to 10:90, preferably 70:30 to 30:70. When the copolymerization ratio is within the above range, the crystallinity of the polyester polycarbonate polyol tends to be reduced, and a polyurethane with high flexibility, good low-temperature properties, and good feel tends to be obtained. Furthermore, when a solvent is used during polyurethane production, a copolymerization ratio within this range tends to allow the amount of solvent used to be reduced.

[0035] In this embodiment, when three types of repeating units of formula (3), formula (4), and formula (5) are selected, the proportion of the structural units of formula (3), formula (4), and formula (5) is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more, when the total of the three types of repeating units of formula (3), formula (4), and formula (5) is 100 mol%. When the proportion of each of the three types of repeating units of formula (3), formula (4), and formula (5) in the total of the three types of repeating units of formula (3), formula (4), and formula (5) is within the above range, the crystallinity of the polycarbonate diol tends to be reduced, and a polyurethane with high flexibility, good low-temperature properties, and good feel tends to be obtained. Furthermore, when a solvent is used in producing the polyurethane, when the proportion of each of the three types of repeating units of formula (3), formula (4), and formula (5) is within the above range, the amount of solvent used tends to be reduced.

[0036] Dibasic acids that can be used in the synthesis of the polyester polycarbonate polyol of this embodiment include aliphatic and / or aromatic dicarboxylic acids. Examples of aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid. Examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, and terephthalic acid. To obtain polyurethanes with excellent flexibility, aliphatic dicarboxylic acids are particularly preferred, with succinic acid, glutaric acid, and adipic acid being particularly preferred. These dicarboxylic acids can also be used as alcohol esters, such as methyl esters of dimethyl succinate, dimethyl glutarate, and dimethyl adipate. These dicarboxylic acids can be used alone or in combination.

[0037] In the polyester polycarbonate polyol of this embodiment, the molar ratio of the polycarbonate structural unit represented by formula (1) to the polyester structural unit represented by formula (2) is preferably 50 / 50 to 95 / 5, more preferably 60 / 40 to 90 / 10, and even more preferably 70 / 30 to 80 / 20. When the molar ratio of the polycarbonate structural unit represented by formula (1) to the polyester structural unit represented by formula (2) is within the above range, a polyurethane having excellent flexibility, chemical resistance, adhesiveness, and hydrolysis resistance can be obtained.

[0038] Examples of carbonate esters that can be used in synthesizing the polyester polycarbonate polyol of this embodiment 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, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, and 1,2-pentylene carbonate. From the viewpoints of ease of availability and ease of setting polymerization reaction conditions, it is preferable to use dimethyl carbonate, diethyl carbonate, diphenyl carbonate, or ethylene carbonate as the carbonate ester.

[0039] A catalyst may or may not be added when producing the polyester polycarbonate polyol of this embodiment. When a catalyst is added, it can be freely selected from catalysts used in ordinary transesterification reactions. Examples of catalysts that can be used include metals such as lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, zinc, aluminum, titanium, zirconium, hafnium, cobalt, germanium, tin, lead, antimony, arsenic, and cerium, as well as metal salts, metal alkoxides, and organic compounds containing these metals. Among the above catalysts, metal alkoxides are preferred, and alkoxides of metals selected from titanium, zirconium, and hafnium, which are metals in Group 4 of the periodic table, are particularly preferred because they are less susceptible to the effects of water produced and can maintain high activity. The amount of catalyst used is usually 0.00001 to 0.1 mass%, preferably 0.001 to 0.05 mass%, and more preferably 0.01 to 0.03 mass% of the mass of the starting materials (bifunctional diol compound and optionally trifunctional or higher polyhydric alcohol). When the amount of catalyst is 0.0001 mass% or more, the reaction rate can be shortened, improving productivity. When the amount of catalyst is 0.1 mass% or less, the color tone of the resulting polyester carbonate polyol is excellent.

[0040] In the method for producing the polyester polycarbonate polyol in this embodiment, as described above, the polyester polycarbonate polyol can be synthesized by transesterification using a bifunctional diol compound (and optionally a trifunctional or higher polyhydric alcohol), a dibasic acid, and a carbonate ester as raw materials. More specifically, the transesterification reaction is carried out according to the following procedure. First, one or more bifunctional diol compounds (and, if necessary, one or more trifunctional or higher polyhydric alcohols in a predetermined ratio), a dibasic acid in a predetermined ratio, and one or more carbonate esters in a predetermined ratio are mixed together, and an ester exchange reaction is carried out at normal pressure or reduced pressure in the absence or presence of an ester exchange catalyst at a temperature of 100 to 200°C, preferably 140 to 180°C. Subsequently, the alcohol derived from the carbonate ester and the water derived from the dibasic acid (when a dibasic acid ester is used, the monoalcohol derived from the dibasic acid ester) produced during the reaction are distilled off to obtain a polyester polycarbonate polyol having a molecular weight of about 300 to 500 g / mol. Next, under reduced pressure at 130 to 230°C, preferably 150 to 200°C, the unreacted carbonate ester, bifunctional diol (and optionally trifunctional or higher polyhydric alcohol), and water produced by the condensation reaction of the dibasic acid (when a dibasic acid ester is used, the monoalcohol derived from the dibasic acid ester) are distilled off, and a polyester polycarbonate polyol with the desired hydroxyl value is obtained by a condensation reaction. The hydroxyl value of the polyester polycarbonate polyol can be adjusted by controlling the initial charging ratio of each component, the amount of each raw material distilled during production, and the amount of reaction product.

[0041] Alternatively, the polyester polycarbonate polyol of the present embodiment can be produced by first producing a polycarbonate polyol and a polyester polyol, then mixing the polycarbonate polyol and the polyester polyol, and carrying out a transesterification reaction at a temperature of 100 to 200°C under stirring in the presence or absence of the transesterification catalyst.

[0042] In one aspect, the present embodiment relates to a method for producing a polyester polycarbonate polyol of the present embodiment described above, characterized in that a metal alkoxide is used as a catalyst for transesterification, and is preferably an alkoxide of a metal of Group 4 of the periodic table. In one embodiment, the above production method includes a step of subjecting a bifunctional diol compound (and optionally a trifunctional or higher polyhydric alcohol) to a transesterification reaction with a dibasic acid and a carbonate ester using a metal alkoxide as a catalyst. In one embodiment, the above production method includes a step of reacting a bifunctional diol compound (and optionally a trifunctional or higher polyhydric alcohol) with a dibasic acid to obtain a polycarbonate polyol, a step of reacting a dibasic acid with a carbonate ester to obtain a polyester polyol, and a step of subjecting the polycarbonate polyol and the polyester polyol to a transesterification reaction using a metal alkoxide as a catalyst.

[0043] In the method for producing polyurethane using the polyester polycarbonate polyol of the present embodiment (hereinafter, component (a)), a curing agent such as polyisocyanate (hereinafter, component (b)) and, if necessary, a chain extender (hereinafter, component (c)) are usually used. In the method for producing a polyurethane using the polyester polycarbonate polyol of this embodiment, the constituent components (a), (b), and (c) may be blended all at once to form a mixture to produce a curable composition (one-shot method), or the curable composition may be prepared by first reacting component (a) with component (b) to prepare an isocyanate-terminated prepolymer composition, and then blending this isocyanate-terminated prepolymer composition with component (c) to produce a mixture to produce a curable composition (prepolymer method).

[0044] When producing polyurethane using the polyester polycarbonate polyol of this embodiment, the polyisocyanate that can be used is usually a polyisocyanate having an average of 2 to 6 functional groups per molecule (component (b)). Examples of the polyisocyanate of component (b) include aromatic diisocyanates such as 2,4-tolyresin diisocyanate, 2,6-tolyresin diisocyanate, and mixtures thereof, diphenylmethane-4,4'-diisocyanate (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3'-dimethyl-4,4'biphenylene diisocyanate (TODI), and polymethylene polyphenylene polyisocyanate (PMDI); aromatic aliphatic diisocyanates such as xylylene diisocyanate (XDI) and phenylene diisocyanate; and aliphatic diisocyanates such as 4,4'-methylenebiscyclohexyl diisocyanate (hydrogenated MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and cyclohexane diisocyanate (hydrogenated XDI).

[0045] The polyisocyanate of component (b) may be a polyisocyanate having an average of 2.1 or more isocyanate groups per molecule, such as aromatic polyisocyanates such as crude MDI and crude TDI; derivatives of aliphatic isocyanates such as HDI and IPDI, specifically diisocyanate derivatives such as biuret, allophanate, uretdione, and isocyanurate; and polyhydric alcohol adducts. The polyisocyanate having 2.1 or more isocyanate groups per molecule is not particularly limited, but examples thereof include Sumidur 44S, 44V70 (both manufactured by Sumika Bayer Urethane), Dismodur HL (manufactured by Sumika Bayer Urethane), which is a copolymer of TDI and HDI, and various Duranates manufactured by Asahi Kasei Corporation, namely, Duranate 24A-100, Duranate 22A-75PX, Duranate 18H-70B, Duranate 21S-75E, Duranate THA-100, Duranate TPA-100, Duranate-TKA100, Duranate MFA-75X, Duranate TSA-100, Duranate 21S-75E ... These are available as Duranate TSS-100, Duranate TSE-100, Duranate D-101, Duranate D-201, Duranate P-301-75E, 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, and Duranate WT30-100.

[0046] It is preferable to use an aromatic polyisocyanate such as MDI as the polyisocyanate of component (b). The use of an aromatic polyisocyanate tends to result in a polyurethane with excellent mechanical properties. When an aromatic polyisocyanate such as MDI is used as component (b) in the curable composition, the curable composition can be suitably used as an adhesive between the base fabric and the surface layer of synthetic leather. Furthermore, when an aliphatic polyisocyanate such as hydrogenated MDI is used as component (b) in the curable composition, the curable composition can provide synthetic leather with excellent weather resistance, and therefore the curable composition is suitably used as a curable composition for synthetic leather for the surface layer, etc.

[0047] As component (b), it is also possible to use so-called blocked isocyanates obtained by blocking a polyisocyanate with a known blocking agent, such as a lower alcohol such as butanol or 2-ethylhexanol, methyl ethyl ketone oxime, lactams, phenols, imidazoles, or an active methylene compound.

[0048] When producing polyurethane using the polyester polycarbonate polyol of this embodiment, a chain extender (component (c)) can be used as needed. Chain extenders are used to improve the abrasion resistance and strength of the resulting polyurethane, but they can also reduce the flexibility of the resulting polyurethane, so they are used appropriately and as needed. Examples of chain extenders include, but are not limited to, short-chain diols such as ethylene glycol and 1,4-butanediol; polyhydric alcohols such as trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol, and glycerin; and the like. Examples of chain extenders include, but are not limited to, diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, xylylenediamine, diphenyldiamine, diaminodiphenylmethane, diaminocyclohexylmethane, piperazine, 2-methylpiperazine, isophoronediamine, and 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA); and water.

[0049] The amount of the chain extender added is preferably 30% by mass or less, more preferably 3% by mass or more and 20% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less, based on the total amount of components (a) and (b). Furthermore, by using a polyhydric alcohol as a chain extender, the crosslink density of the resulting polyurethane can be increased, and the strength, abrasion resistance, and chemical resistance can be improved.

[0050] The amounts of the polyester polycarbonate polyol (a), the polyisocyanate (b), and the chain extender (c) used are adjusted so that the ratio (isocyanate equivalent of component (b) / total hydroxyl equivalents of both components (a) and (c)) is preferably 0.7 to 1.3, more preferably 0.8 to 1.2, and even more preferably 0.9 to 1.1. When the ratio (isocyanate equivalent of component (b) / total hydroxyl equivalents of both components (a) and (c)) is 0.7 or more and 1.3 or less, the molecular weight of the resulting polyurethane can be appropriately controlled, and the resulting polyurethane tends to have excellent mechanical properties such as strength, elongation, and abrasion resistance.

[0051] When polyurethane is produced using the polyester polycarbonate polyol of this embodiment, an inert organic solvent may be added as necessary to adjust workability during urethane production. The content of the inert organic solvent is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, based on the polyurethane. Addition of an inert organic solvent is effective for reducing the viscosity of the curable composition, improving its workability, and further improving the appearance of the resulting polyurethane.

[0052] The inert organic solvent is not particularly limited as long as it is an organic solvent that is substantially inert to polyisocyanate, and preferably does not contain active hydrogen. Examples of inert organic solvents include, but are not limited to, hydrocarbons such as pentane, hexane, heptane, octane, decane, petroleum ether, petroleum benzine, ligroin, petroleum spirit, cyclohexane, and methylcyclohexane; fluorinated inert liquids such as trichlorofluoroethane, tetrachlorodifluoroethane, and perfluoroether; perfluorocyclohexane, perfluorobutyltetrahydrofuran, perfluorodecalin, perfluoro-n-butylamine, perfluoropolyether, and dimethylpolysiloxane. These may be used alone or in combination. Further examples of inert organic solvents include methyl ethyl ketone (also referred to as MEK), acetone, N,N-dimethylformamide (DMF), ethyl acetate, butyl acetate, toluene, and xylene, either alone or in combination.

[0053] When a polyurethane is produced using the polyester polycarbonate polyol of the present embodiment, a polyol other than the polyester polycarbonate polyol may be used in combination as necessary. The polyol other than the polyester polycarbonate polyol is not particularly limited, and examples thereof include polyether polyols, polyester polyols, polycarbonate polyols, polyolefin polyols, polybutadiene polyols, polyacrylic polyols, and oil-modified polyols. The amount of polyol other than polyester polycarbonate polyol added is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, based on the combined mass of polyester polycarbonate polyol and polyol other than polyester polycarbonate polyol.

[0054] <Other additives> When polyurethane is produced using the polyester polycarbonate polyol of the present embodiment, curing accelerators (catalysts), fillers, flame retardants, dyes, organic or inorganic pigments, mold release agents, flowability modifiers, plasticizers, antioxidants, ultraviolet absorbers, light stabilizers, antifoaming agents, leveling agents, colorants, foaming agents, and the like may be added depending on the intended use.

[0055] The curing accelerator is not particularly limited, but includes amines and metal catalysts. The amine effect accelerator is not particularly limited, but examples thereof include monoamines such as triethylamine and N,N-dimethylcyclohexylamine, diamines such as tetramethylethylenediamine, other triamines, cyclic amines, alcohol amines such as dimethylethanolamine, and ether amines. The metal catalyst is not particularly limited, but 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, and phospholine.

[0056] The filler or pigment is not particularly limited, but examples thereof include woven fabric, glass fiber, carbon fiber, polyamide fiber, mica, kaolin, bentonite, metal powder, azo pigment, carbon black, clay, silica, talc, gypsum, alumina white, and barium carbonate.

[0057] The release agent, flow control agent, and leveling agent are not particularly limited, but examples thereof include silicone, aerosil, wax, stearates, and polysiloxanes such as BYK-331 (manufactured by BYK Chemicals).

[0058] When polyurethane is produced using the polyester polycarbonate polyol of this embodiment, it is preferable to use an antioxidant, a light stabilizer, and a heat stabilizer as additives. The antioxidant is not particularly limited, but examples thereof include aliphatic, aromatic, or alkyl group-substituted aromatic esters of phosphoric acid or phosphorous acid, hypophosphorous acid derivatives, phosphorus compounds such as phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonates, dialkylpentaerythritol diphosphites, and dialkylbisphenol A diphosphites; phenol derivatives, particularly hindered phenol compounds; sulfur-containing compounds such as thioethers, dithioacid salts, mercaptobenzimidazoles, thiocarbanilides, and thiodipropionates; and tin compounds such as tin maleates and dibutyltin monoxide. These may be used alone or in combination of two or more.

[0059] <Manufacturing method for synthetic leather> Synthetic leather can be produced by applying the method for producing polyurethane using the polyester polycarbonate polyol of this embodiment. Examples of methods for producing synthetic leather using the polyester polycarbonate polyol of this embodiment include a wet method in which a polyurethane produced using the polyester polycarbonate polyol of this embodiment is applied to or impregnated into a substrate (base fabric) and wet-coagulated, and a dry method in which a polyurethane produced using the polyester polycarbonate polyol of this embodiment is applied to release paper or a substrate (base fabric) and dried. Furthermore, as a method for producing synthetic leather, a transfer coating method (a type of dry method) can also be used, in which a polyurethane produced using the polyester polycarbonate polyol of the present embodiment is applied to release paper to form a skin material, and then another polyurethane produced using the polyester polycarbonate polyol of the present embodiment is used as an adhesive layer on top of the skin material, and the release paper is removed after bonding to a substrate (base fabric).

[0060] The method for producing synthetic leather will be explained below using the dry method as an example. Various substrates (base fabrics) can be used, including, for example, fibrous substrates. Examples of fibrous substrates include fiber assemblies in the form of nonwoven fabrics, woven fabrics, mesh fabrics, etc., or fiber assemblies in which the fibers are bonded together with an elastic polymer. Examples of fibers used in these fiber assemblies include natural fibers such as cotton, linen, and wool; recycled or semi-synthetic fibers such as rayon and acetate; and synthetic fibers such as polyamide, polyester, polyacrylonitrile, polyvinyl alcohol, and polyolefin. These fibers may be spun as a single fiber or a blend of spun fibers. Other substrates include paper, release paper, polyester or polyolefin plastic films, metal plates such as aluminum, and glass plates.

[0061] The polyurethane produced using the polyester polycarbonate polyol of the present embodiment can be applied by a commonly used method, such as a floating knife coater, a knife-over-roll coater, a reverse roll coater, a roll doctor coater, a gravure roll coater, or a kiss roll coater.

[0062] The resulting synthetic leather can be used as is. Alternatively, to impart various additional properties, the synthetic leather can be coated with a polymer solution or emulsion such as polyurethane resin, vinyl chloride, or cellulose-based resin. The synthetic leather can also be obtained in the form of a laminate obtained by laminating a coating film obtained by drying the polymer solution or emulsion coated on a separate release paper, and then peeling off the release paper.

[0063] The present embodiment will be described below with reference to the drawings. The drawings and manufacturing conditions described below are one example of the present embodiment, and the present embodiment is not limited thereto.

[0064] Figure 1 is a schematic cross-sectional view of a synthetic leather laminate produced by the dry method shown in Figure 2. The structure of this laminate has a surface layer 2 on a substrate (nonwoven fabric) 4 with an adhesive layer 3 interposed therebetween. The outermost layer has release paper 1, which was used during production, attached, but is peeled off before use.

[0065] 2 is a schematic diagram showing one method for producing a dry-laid synthetic leather laminate sheet using polyurethane, which is produced using the polyester polycarbonate polyol of this embodiment. In this production method, first, raw materials adjusted to a predetermined temperature are mixed in a mixing head 5 to obtain a curable composition, which is then poured onto release paper 1 (usually having a leather-like pattern). When the one-shot method is applied, component (a), component (b), and optionally component (c), and optionally an inert organic solvent and additives, are fed separately, or component (b) and other raw materials (a mixture of component (a), component (c), and optionally an inert organic solvent and additives) are continuously fed into a mixing head 5, mixed, and allowed to flow down onto the release paper 1. When the prepolymer method is applied, a mixture of a prepolymer composition, a non-prepolymerized polycarbonate polyol (component (a)) and / or a chain extender (component (c)), and, if necessary, an inert organic solvent and additives is continuously fed into a mixing head 5, mixed, and allowed to flow down onto a release paper 1.

[0066] Before mixing, the components are adjusted to a temperature of typically 20 to 80°C, preferably 30 to 70°C, and more preferably 40 to 60°C. The temperature of the mixing head 5 is also adjusted to a temperature of typically 20 to 80°C, preferably 30 to 70°C, and more preferably 40 to 60°C. By keeping the temperatures of the components and the mixing head 5 at 20°C or higher before mixing, the viscosity of the raw materials used, particularly the polycarbonate polyol, tends to be suppressed, and the flow rate tends to be stable. By keeping the temperatures of the components and the mixing head 5 at 80°C or lower before mixing, the curing rate of the curable polyurethane produced from the polyester polycarbonate polyol of this embodiment is appropriately controlled, a rapid increase in viscosity is suppressed, and synthetic leather of uniform thickness tends to be obtained.

[0067] The mixture is then passed through a coating roll 8 to form a sheet of a uniform thickness, and then passed through a dryer 11 to harden and dry the inert organic solvent, forming the synthetic leather skin layer 2. The temperature of the dryer is usually set to 60 to 150°C, preferably 70 to 130°C, and more preferably 80 to 120°C. The drying time is usually 2 to 15 minutes, preferably 3 to 10 minutes, and more preferably 4 to 7 minutes.

[0068] Next, the raw materials of the curable polyurethane composition, which have been adjusted to a predetermined temperature in advance, are mixed in a mixing head 6, and the resulting curable composition is allowed to flow down to form the adhesive layer 3. When the one-shot method is applied to the production of the adhesive layer, components (a), (b), and (c), as well as an inert organic solvent and additives as required, are fed separately, or component (b) is continuously fed into a mixing head 6 as a mixture of the other raw material components (a), (c), as required, an inert organic solvent, and additives, and the mixture is then mixed and allowed to flow down onto the skin layer. When the prepolymer method is applied to the production of the adhesive layer, the prepolymer composition and the non-prepolymerized polyol (component (a)), optionally an inert organic solvent, and additives are fed separately, or alternatively, the prepolymer composition and a mixture of other raw materials (non-prepolymerized polyol (component (a) and / or a chain extender (component (c)), optionally an inert organic solvent, and additives)) are continuously fed into a mixing head 6, mixed, and allowed to flow down onto the surface layer.

[0069] Before mixing, the components are adjusted to a temperature of typically 20 to 60°C, preferably 30 to 50°C, and more preferably 35 to 45°C. The temperature of the mixing head 6 is also adjusted to a temperature of typically 20 to 60°C, preferably 30 to 50°C, and more preferably 35 to 45°C. By keeping the temperatures of the components before mixing and the temperature of the mixing head 6 at 20°C or higher, the viscosity of the raw materials used, particularly the polyester polycarbonate polyol, tends to be reduced, and the flow rate tends to be stable. By keeping the temperatures of the components before mixing and the temperature of the mixing head 6 at 60°C or lower, the curing rate of the curable composition is appropriately controlled, a rapid increase in the viscosity of the curable composition is suppressed, and a synthetic leather with a uniform thickness tends to be obtained.

[0070] The mixture is then passed through a coating roll 8 to form a sheet of a certain thickness, which is then passed through a dryer 11 to harden and dry the inert organic solvent, forming a synthetic leather adhesive layer 3. Next, the substrate 4 and adhesive layer 3 are superimposed and pressed together with a pressure roll 9 to obtain a post-sheet structure 7, which is then taken up on a take-up roll 10 to obtain the desired synthetic leather laminate. The temperature of the dryer 11 is typically set to 60 to 150°C, preferably 70 to 130°C, and more preferably 80 to 120°C. The drying time is typically 2 to 15 minutes, preferably 3 to 10 minutes, and more preferably 4 to 7 minutes.

[0071] While FIG. 2 shows an example of the production of synthetic leather comprising three layers: a skin layer, an adhesive layer, and a substrate, a synthetic leather laminate comprising two layers (skin layer / substrate) without the adhesive layer can also be produced using the same equipment. The adhesion between the skin layer and the substrate is controlled by adjusting the curing state of the curable composition. Specifically, this can be achieved by pressing the curable composition onto the substrate in a state where it is not completely cured. Therefore, the curing temperature of the dryer 11 is set to 60 to 150°C, preferably 70 to 130°C, and more preferably 80 to 120°C. The drying time is usually set to 2 to 15 minutes, preferably 3 to 10 minutes, and more preferably 4 to 7 minutes.

[0072] <Application> Synthetic leather obtained using a polyurethane produced using the polyester polycarbonate polyol of this embodiment can be used for automobile interior materials such as automobile seats, furniture such as sofas, clothing, shoes, bags, and other miscellaneous products. It can also be used as a laminating adhesive for various films, a surface protective agent, etc. [Example]

[0073] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples as long as it does not depart from the gist of the invention. In the following examples and comparative examples, the methods for analyzing and evaluating the physical properties of each component are as follows.

[0074] [Analysis and Evaluation of Polyester Polycarbonate Polyols] <Hydroxyl value of polyester polycarbonate polyol> Measurement was carried out in accordance with JIS K1557-1.

[0075] <Polyester polycarbonate polyol composition (copolymerization ratio)> A 1g sample of polyester polycarbonate polyol was placed in a 100mL recovery flask, and 30g of methanol and 8g of 28% sodium methoxide in methanol were added. The mixture was then allowed to react at 100°C for 1 hour. After cooling to room temperature, 2-3 drops of phenolphthalein were added as an indicator and neutralized with hydrochloric acid. After cooling in a refrigerator for 1 hour, the mixture was filtered and analyzed by gas chromatography (GC). GC analysis was performed using a GC-14B gas chromatograph (Shimadzu Corporation, Japan) equipped with a DB-WAX (J&W, USA) column. The GC analysis was performed using diethylene glycol diethyl ester as the internal standard and a flame ionization detector (FID) as the detector. The column temperature profile was maintained at 60°C for 5 minutes, followed by a 10°C / min increase to 250°C. The composition (copolymerization ratio) of the polyester polycarbonate polyol was determined from the alcohol components and the methyl ester components derived from the dibasic acid detected from the above analysis results. For the composition of polyester polycarbonate polyols containing dibasic acids, the number of moles of diols constituting the carbonate skeleton can be determined by subtracting the same number of moles of diol from the number of moles of methyl ester derived from the dibasic acid (when multiple diols are used, the calculation is performed assuming that the composition of the diol in the carbonate skeleton and the composition of the diol in the ester skeleton are the same, based on the ratio of diols determined by gas chromatography).

[0076] <Melt viscosity measurement> The polyester polycarbonate polyol was preheated to 50°C, and then the melt viscosity was measured at 50°C using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TVE-22HT, cone No. 6).

[0077] <Carbonate group content of polyester polycarbonate polyol> The carbonate group content is the amount of carbonate groups contained in one molecule of the polyester polycarbonate diol, and is specifically calculated by the following formula (6).

[0078] Carbonate group content (%) = (molecular weight of carbonate group) × (number of carbonate groups per molecule) / (number average molecular weight of polyester polycarbonate polyol) × 100 (6) (Here, the molecular weight of the carbonate group (-OC=OO-) is 60.01.)

[0079] The number of carbonate groups in one molecule was calculated from the number of repeating units (x) of the carbonate structure using the following formula (8) based on the structure of the following formula (7). [ka] (Here, m is the average number of methylene groups in the diol, x is the number of repeating units of the carbonate structural skeleton in one molecule, y is the number of repeating units of the ester structural skeleton, and the underlined parts represent the terminal groups. R2 represents the hydrocarbon derived from the dibasic acid used.)

[0080] The structure of each segment constituting the polycarbonate was determined from the composition of the polyester polycarbonate polyol obtained from the above <Composition (copolymerization ratio) of polyester polycarbonate polyol>. From this, the number of methylene groups in each constituting segment was determined, and the average number of methylene groups (m) was calculated from the ratio.

[0081] Number of carbonate group repeat units (x) = [(number average molecular weight (Mn) - (molecular weight of ester skeleton) - (molecular weight of terminal group)) / (molecular weight of carbonate skeleton repeating unit) (8)

[0082] In formula (8), the molecular weight of the ester skeleton is determined from the composition of the carbonate skeleton and the composition of the ester skeleton determined by gas chromatography. Specifically, the molecular weight of the ester skeleton is calculated by multiplying the molecular weight obtained by subtracting the average molecular weight of the average terminal diol group from the average molecular weight of the polyester polycarbonate polyol by the mass ratio obtained by converting the molar composition of the ester skeleton determined separately by gas chromatography into a mass composition.

[0083] [Analysis and evaluation of polyurethane films] <Preparation of polyurethane film> Each component of the curable composition of the present invention, preheated to 40°C, was added to a 200 mL separable four-neck flask equipped with a stirring blade (four paddles inclined at 45°C) under a nitrogen atmosphere in an amount equivalent to 80 g of curable composition. After stirring at 40°C for 5 minutes, the composition was applied to a polypropylene resin sheet (100 mm wide, 1200 mm long, 1 mm thick) using an applicator to a width of 80 mm, length of 100 mm, and thickness of 0.6 mm. The composition was then dried on a hot plate at a surface temperature of 60°C for 2 hours and then in an oven at 100°C for 12 hours. The resulting polyurethane film was then left to stand at a constant temperature and humidity of 23°C and 55% RH for at least 12 hours to obtain a polyurethane film. The resulting polyurethane film was then subjected to evaluation of various physical properties.

[0084] <Flexibility of polyurethane film> The flexibility of the polyurethane film was evaluated by five examiners who evaluated the feel of the film when touched with their hands. The evaluation criteria were as follows: ○ indicates flexibility, and the evaluation results of the five inspectors were consistent. △ indicates that the product was slightly hard, and the evaluation results of the five inspectors were consistent. The symbol × indicates that the sample was hard, and the evaluation results of the five inspectors were consistent.

[0085] <Appearance of polyurethane film> The surface appearance of the polyurethane film prepared above was visually evaluated according to the following criteria. A circle indicates that the surface was smooth. △ indicates that a few streaks were observed on the surface in the direction of applicator movement. × indicates that many streaks were observed on the surface in the direction of applicator movement.

[0086] <Molecular weight measurement> A portion of the polyurethane film was cut out, and an N,N-dimethylacetamide solution was prepared to give a polyurethane concentration of 0.1% by mass. The number-average molecular weight (Mn) was measured in terms of standard polystyrene using a GPC system (Tosoh Corporation, product name "HLC-8320" (column: Tskgel SuperHM-H x 4), using a solution of 2.6 g of lithium bromide dissolved in 1 L of dimethylacetamide as the eluent).

[0087] <Evaluation of resistance to oleic acid> A 3cm x 3cm test piece was cut from the polyurethane film. After measuring the weight of the test piece using a precision balance, it was placed in a 250mL glass bottle containing 50mL of oleic acid as the test solvent and left to stand in a constant temperature bath at 80°C under a nitrogen atmosphere for 16 hours. After the test, the test piece was removed and lightly wiped on both sides with a paper wiper. The weight was then measured using a precision balance and the weight change rate (rate of increase) from before the test was calculated. A weight change rate closer to 0% indicates better resistance to oleic acid.

[0088] <Evaluation of ethanol resistance> After preparing a urethane film using the same method as described above in <Evaluation of oleic acid resistance>, a 3 cm x 3 cm test piece was cut out of the urethane film. The weight of the test piece was measured using a precision balance, and then it was placed in a glass Petri dish with an inner diameter of 10 cm containing 50 mL of ethanol as the test solvent and immersed for 1 hour at room temperature of approximately 23°C. After the test, the test piece was removed and lightly wiped with a paper wiper, and then its weight was measured using a precision balance, and the weight change rate (rate of increase) from before the test was calculated. A weight change rate closer to 0% indicates better ethanol resistance.

[0089] <Measurement of glass transition temperature (Tg)> A test piece measuring 10 mm wide, 40 mm long, and 0.4 mm thick was cut from the polyurethane film. Using a viscoelasticity measuring device (Hitachi High-Tech Science Corporation, TA7000 series, DMA7100), the test piece was set with a chuck distance of 20 mm, and the viscoelasticity was measured while the temperature was raised from -100°C to 100°C at a rate of 5°C / min. The glass transition temperature (Tg) was calculated from the peak value of tan δ.

[0090] <Room temperature tensile test> In accordance with JIS K6301 (2010), a tensile test was carried out on rectangular polyurethane test pieces measuring 10 mm in width, 100 mm in length, and approximately 0.5 mm in thickness using a tensile testing machine (manufactured by Orientec Co., Ltd., product name "Tensilon, Model RTE-1210") at a chuck distance of 20 mm, a tensile speed of 100 mm / min, and a temperature of 23°C (relative humidity of 55%). The stress at the time when the test piece was elongated to 100%, as well as the strength at break and elongation at break were measured.

[0091] <Low temperature tensile test> In accordance with JIS K6301 (2010), rectangular polyurethane test pieces measuring 10 mm in width, 100 mm in length, and approximately 0.5 mm in thickness were prepared. The film was placed on a tensile testing machine (manufactured by Orientec Co., Ltd., product name "Tensilon," model RTE-1210) equipped with a thermostatic chamber (manufactured by Orientec Co., Ltd., "Model TLF-R3T-EW") with a chuck distance of 20 mm. The test pieces were then left to stand at -20°C for 5 minutes, after which a tensile test was carried out at a tensile speed of 100 mm / min, and the stress at the point when the test pieces were elongated to 100% was measured.

[0092] <Evaluation of heat resistance> The polyurethane film was cut into a strip of 10 mm width, 100 mm length, and approximately 50 μm thickness, and heated in a gear oven at 120°C for 1000 hours. After heating, the sample was measured for breaking strength in the same manner as in the above <Room temperature tensile test>, and its retention rate (%) was calculated.

[0093] <Evaluation of hydrolysis resistance> The polyurethane film was cut into a strip of 10 mm wide, 100 mm long, and approximately 50 μm thick, and heated in a thermo-hygrostat at 70°C and 95% relative humidity for 400 hours. After heating, the samples were measured for breaking strength in the same manner as in the above <Room temperature tensile test>, and the retention rate (%) was calculated.

[0094] [Analysis and evaluation of synthetic leather] <Flexibility of synthetic leather> The softness of the synthetic leather was evaluated by five panelists who evaluated the feel of the synthetic leather when touched with their hands. The evaluation criteria were as follows: ○ indicates flexibility, and the evaluation results of the five inspectors were consistent. △ indicates that the product was slightly hard, and the evaluation results of the five inspectors were consistent. The symbol × indicates that the sample was hard, and the evaluation results of the five inspectors were consistent.

[0095] <Abrasion resistance of synthetic leather> A load of 9.8 N was applied to a friction element covered with cotton cloth to abrade the surface of the synthetic leather. The friction element was rubbed back and forth 10,000 times over a distance of 140 mm on the surface of the synthetic leather at a speed of 60 strokes per minute. The synthetic leather was observed after abrasion and rated according to the following criteria. A circle indicates that the resin layer was free of cracks and tears. △ indicates that cracks occurred in the resin layer. × indicates that the resin layer was torn.

[0096] <Low temperature storage stability of synthetic leather> The synthetic leather was wrapped around a 10 cm diameter paper tube and stored in a thermostatic chamber at -20°C for one month. The synthetic leather was removed from the paper tube and left in a thermostatic chamber at 23°C and 50% humidity for one day, after which the surface was visually inspected. The case where there were no cracks or wrinkles was rated as ◯, the case where there were minute cracks or wrinkles of 1 mm or less was rated as △, and the case where there were cracks or wrinkles of more than 1 mm was rated as x.

[0097] <Method for evaluating adhesiveness> An incision was made in advance at the interface between the polyester base fabric and polyurethane resin layer of the synthetic leather, and the peeled urethane resin layer and base fabric were each fixed in place with a zipper. The peel strength between the polyurethane layer and base fabric was measured in accordance with JIS K6854-2 using a tensile tester (Tensilon Model RTE-1210, manufactured by Orientec Co., Ltd.) at a temperature of 23°C and a speed of 200 mm / min, and this was used to evaluate adhesion.

[0098] [Example 1] [Polymerization Example 1 of Polyester Polycarbonate Polyol] A 2L glass flask equipped with a rectification column filled with structured packing and a stirrer was charged with 221g (2.51mol) of ethylene carbonate, 148g (1.64mol) of 1,4-butanediol, 195g (1.65mol) of 1,6-hexanediol, and 202g (1.38mol) of adipic acid. 0.10g of titanium tetra-n-butoxide was added as a catalyst, and the reaction was carried out for 12 hours at a reaction temperature of 150-170°C, with the pressure reduced from 10kPa to 3kPa, while the resulting water and a mixture of ethylene glycol and ethylene carbonate were distilled off. Thereafter, the reaction was switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa while the reaction was carried out at 170°C for 5 hours to distill off the monomer. The obtained polyester polycarbonate polyol (also referred to as PEC1) was analyzed, and the results are shown in Table 1.

[0099] [Example 2] [Polymerization Example 2 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the amount of adipic acid charged was 171 g (1.17 mol) using the same apparatus as in Polymerization Example 1. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC2) are shown in Table 1.

[0100] [Example 3] [Polymerization Example 3 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the amount of adipic acid charged was 122 g (0.84 mol) using the same apparatus as in Polymerization Example 1. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC3) are shown in Table 1.

[0101] [Example 4] [Polymerization Example 4 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the amount of adipic acid charged was 90 g (0.62 mol) using the same apparatus as in Polymerization Example 1. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC4) are shown in Table 1.

[0102] [Example 5] [Polymerization Example 5 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the amount of adipic acid charged was 49 g (0.33 mol) using the same apparatus as in Polymerization Example 1. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC5) are shown in Table 1.

[0103] [Example 6] [Polymerization Example 6 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the amount of adipic acid charged was 28 g (0.19 mol) using the same apparatus as in Polymerization Example 1. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC6) are shown in Table 1.

[0104] [Example 7] [Polymerization Example 7 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the same apparatus as in Polymerization Example 1 was used and the charged amounts were 221 g (2.51 mol) of ethylene carbonate, 171 g (1.64 mol) of 1,5-pentanediol, 195 g (1.65 mol) of 1,6-hexanediol, and 122 g (0.84 mol) of adipic acid. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC7) are shown in Table 1.

[0105] [Example 8] [Polymerization Example 8 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the same apparatus as in Polymerization Example 1 was used and the charged amounts were 221 g (2.51 mol) of ethylene carbonate, 171 g (1.64 mol) of 1,5-pentanediol, 195 g (1.65 mol) of 1,6-hexanediol, and 90 g (0.62 mol) of adipic acid. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC8) are shown in Table 1.

[0106] [Example 9] [Polymerization Example 9 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the same apparatus as in Polymerization Example 1 was used and the charged amounts were 221 g (2.51 mol) of ethylene carbonate, 171 g (1.64 mol) of 1,5-pentanediol, 195 g (1.65 mol) of 1,6-hexanediol, and 90 g (0.62 mol) of adipic acid. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC9) are shown in Table 1.

[0107] [ Reference example 1 ] [Polymerization Example 10 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the amounts of ethylene carbonate, 1,6-hexanediol, and adipic acid were changed to 250 g (2.84 mol), 494 g (4.18 mol), and 122 g (0.84 mol) using the same apparatus as in Polymerization Example 1. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC10) are shown in Table 1. [ Reference example 2 ] [Polymerization Example 11 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the amounts of ethylene carbonate, 1,4-butanediol, and adipic acid were changed to 250 g (2.84 mol), 377 g (4.18 mol), and 122 g (0.84 mol), respectively, using the same apparatus as in Polymerization Example 1. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC11) are shown in Table 1.

[0108] [Example 12] [Polymerization Example 12 of Polyester Polycarbonate Polyol] Except for changing the polymerization time after switching to simple distillation to 4 hours, polymerization was carried out in the same manner as in Polymerization Example 3. The analysis results of the obtained polycarbonate polyol (also referred to as PEC12) are shown in Table 1.

[0109] [Example 13] [Polymerization Example 13 of Polyester Polycarbonate Polyol] Except for changing the polymerization time after switching to simple distillation to 3 hours, polymerization was carried out in the same manner as in Polymerization Example 3. The analysis results of the obtained polycarbonate polyol (also referred to as PEC13) are shown in Table 1.

[0110] [Example 14] [Polymerization Example 14 of Polyester Polycarbonate Polyol] Except for changing the polymerization time after switching to simple distillation to 7 hours, polymerization was carried out in the same manner as in Polymerization Example 3. The analysis results of the obtained polycarbonate polyol (also referred to as PEC14) are shown in Table 1.

[0111] [Example 15] [Polymerization Example 15 of Polyester Polycarbonate Polyol] Except for changing the polymerization time after switching to simple distillation to 9 hours, polymerization was carried out in the same manner as in Polymerization Example 3. The analysis results of the obtained polycarbonate polyol (also referred to as PEC15) are shown in Table 1.

[0112] [Example 16] [Polymerization Example 16 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the same apparatus as in Polymerization Example 1 was used and the charged amounts were 221 g (2.51 mol) of ethylene carbonate, 185 g (2.05 mol) of 1,4-butanediol, 195 g (1.65 mol) of 1,6-hexanediol, and 122 g (0.84 mol) of adipic acid. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC16) are shown in Table 1.

[0113] [Example 17] [Polymerization Example 17 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the same apparatus as in Polymerization Example 1 was used and the charged amounts were 221 g (2.51 mol) of ethylene carbonate, 92 g (1.02 mol) of 1,4-butanediol, 390 g (3.30 mol) of 1,6-hexanediol, and 122 g (0.84 mol) of adipic acid. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC17) are shown in Table 1.

[0114] [ Reference example 3 ] [Polymerization Example 18 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 3, except that the same apparatus as in Polymerization Example 1 was used, terephthalic acid was used instead of adipic acid, and the amount of terephthalic acid charged was 140 g (0.84 mol). The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC18) are shown in Table 1.

[0115] [Comparative Example 1] [Polymerization Example 19 of Polyester Polycarbonate Polyol] Except for changing the polymerization time after switching to simple distillation to 2 hours, polymerization was carried out in the same manner as in Polymerization Example 3. The analysis results of the obtained polycarbonate polyol (also referred to as PEC19) are shown in Table 1.

[0116] Comparative Example 2 [Polymerization Example 20 of Polyester Polycarbonate Polyol] Except for changing the polymerization time after switching to simple distillation to 11 hours, polymerization was carried out in the same manner as in Polymerization Example 3. The analysis results of the obtained polycarbonate polyol (also referred to as PEC20) are shown in Table 1.

[0117] Comparative Example 3 [Polymerization Example 21 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the amount of adipic acid charged was 280 g (1.92 mol) using the same apparatus as in Polymerization Example 1. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC21) are shown in Table 1.

[0118] Comparative Example 4 [Polymerization Example 22 of Polyester Polycarbonate Polyol] Polymerization was carried out in the same manner as in Polymerization Example 1, except that the amount of adipic acid charged was 20 g (0.14 mol) using the same apparatus as in Polymerization Example 1. The analysis results of the obtained polyester polycarbonate polyol (also referred to as PEC22) are shown in Table 1.

[0119] Comparative Example 5 [Polymerization Example 23 of Polyester Polycarbonate Polyol] A 2L glass flask equipped with a rectification column filled with structured packing and a stirrer was charged with 221g (2.51mol) of ethylene carbonate, 148g (1.64mol) of 1,4-butanediol, 195g (1.65mol) of 1,6-hexanediol, and 158g (1.38mol) of ε-caprolactone. 0.10g of titanium tetrabutoxide was added as a catalyst, and the reaction was carried out for 12 hours at a reaction temperature of 150-170°C, with the pressure reduced from 10kPa to 3kPa, while the resulting water and a mixture of ethylene glycol and ethylene carbonate were distilled off. Thereafter, the reaction was switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa while the reaction was carried out at 170°C for 5 hours to distill off the monomer. The obtained polyester polycarbonate polyol (also referred to as PEC23) was analyzed, and the results are shown in Table 1.

[0120] [Table 1]

[0121] [Example 19] A 500 mL separable flask equipped with a stirrer and sealed with nitrogen gas was charged with 15.34 g (0.06 mol) of diphenylmethane-4,4'-diisocyanate (MDI, average number of isocyanate groups per molecule: 2.0) and 80 g of N,N-dimethylformamide (DMF), and heated to 40 °C to obtain a solution. 60 g of N,N-dimethylformamide (DMF) and 40.0 g (0.02 mol) of polyester polycarbonate polyol PEC1, which had been added with 0.0028 g of dibutyltin dilaurate as a catalyst, were added dropwise to the flask over 30 minutes while stirring the solution. The mixture was allowed to react for 2 hours at 60 °C with stirring to obtain a prepolymer with terminal isocyanate. Next, 3.6 g (0.04 mol) of 1,4-butanediol was added as a chain extender, and the reaction was carried out at 60°C for 1 hour. Then, 0.5 g of ethanol was added as a reaction terminator to obtain a DMF solution of polyurethane (solid content: approximately 30% by mass). The resulting N,N-dimethylformamide (DMF) solution of polyurethane was applied to a glass plate and heated at 80°C for 2 hours to produce a 50 μm thick polyurethane film. After leaving it at room temperature for 24 hours, various physical properties were evaluated. The evaluation results are shown in Table 2.

[0122] [Example 20 27, 30 to 35 and Reference Examples 4 to 6 ] Polyurethane films were obtained in the same manner as in Example 1, except that PEC2 to PEC18 were used as the polyester polycarbonate polyols and the masses of the polyester polycarbonates used were set to the masses shown in Table 2, and the films were subjected to evaluation of various physical properties. The evaluation results are shown in Table 2.

[0123] [Comparative Examples 6 to 10] Polyurethane films were obtained in the same manner as in Example 1, except that PEC19 to PEC23 were used as the polyester polycarbonate polyols and the masses of the polyester polycarbonates used were set to the masses shown in Table 1, and the films were subjected to evaluation of various physical properties. The evaluation results are shown in Table 2.

[0124] [Table 2]

[0125] [Example 37] A 500 mL separable flask equipped with a stirrer and sealed with nitrogen gas was charged with 15.74 g (0.06 mol) of 4,4'-methylenebiscyclohexyl diisocyanate (hydrogenated MDI, average number of isocyanate groups per molecule: 2.0) and 80 g of N,N-dimethylformamide (DMF), and heated to 50 °C to obtain a solution. 60 g of N,N-dimethylformamide (DMF) and 40 g (0.02 mol) of polyester polycarbonate polyol PEC2, containing 0.0028 g of dibutyltin dilaurate as a catalyst, were added dropwise to the flask over 30 minutes while stirring. The reaction was continued for 2 hours at 70 °C with stirring to obtain a prepolymer with terminal isocyanate. Next, 6.8 g (0.04 mol) of isophoronediamine was added as a chain extender, and the reaction was carried out at 70°C for 2 hours. After that, 0.5 g of ethanol was added as a reaction terminator to obtain a DMF solution of polyurethane (solid content: approximately 30% by mass). The resulting N,N-dimethylformamide (DMF) solution of polyurethane was applied to a glass plate and heated at 80°C for 2 hours to produce a 50 μm thick polyurethane film. After leaving it at room temperature for 24 hours, various physical properties were evaluated. The evaluation results are shown in Table 3.

[0126] [Example 38~ 41, 44, 45 and Reference Examples 7 to 9 ] Polyurethane films were obtained in the same manner as in Example 37, except that PEC3, 4, 5, 8, 10, 11, 13, 14, and 18 were used as the polyester polycarbonate polyol, and the physical properties were evaluated. The evaluation results are shown in Table 3.

[0127] [Comparative Examples 11 to 15] Except for using PC19 to PC23 as the polyester polycarbonate polyol, polyurethane films were obtained in the same manner as in Example 1 and subjected to evaluation of various physical properties. The evaluation results are shown in Table 3.

[0128] [Table 3]

[0129] [Example 47] Using an apparatus similar to that shown in Figure 2, a release paper with a grain pattern (R-8, manufactured by Lintec Corporation) was used, and a composition having the same composition ratio as in Example 38 (two components, a prepolymer obtained by reacting isocyanate with polyester polycarbonate polyol and a chain extender, were mixed continuously at a temperature of 70 ° C. in a mixing head just beforehand), which was continuously flowed down onto the release paper and adjusted to a thickness of 50 μm with a coating roll. The mixture was passed through a dryer at 120 ° C. to form a urethane layer that would become the surface layer. Next, a composition having the same composition ratio as in Example 21 (a prepolymer obtained by reacting isocyanate with polyester polycarbonate polyol and a chain extender were mixed continuously in a mixing head at 70 ° C. immediately beforehand) was continuously mixed in a mixing head at 40 ° C., continuously flowed onto release paper, and adjusted to a thickness of 250 μm with a coating roll. The mixture was passed through a dryer at 120 ° C. to form a urethane layer that would become the adhesive layer. The resulting synthetic leather was evaluated, and the results are shown in Table 4.

[0130] [Example 48~ 49, 52, 53 and Reference Examples 10 to 12 ] Synthetic leather consisting of a polyurethane laminate was obtained in the same manner as in Example 47, except that compositions having the same composition ratios as in the Examples shown in Table 4 were used to form the polyurethane that would become the surface layer and the polyurethane that would become the adhesive layer. The synthetic leather obtained was evaluated, and the results are shown in Table 4.

[0131] [Comparative Examples 15 to 19] Synthetic leather consisting of a polyurethane laminate was obtained in the same manner as in Example 47, except that compositions having the same composition ratios as in the Comparative Examples shown in Table 4 were used to form the polyurethane that would become the surface layer and the polyurethane that would become the adhesive layer. The synthetic leather obtained was evaluated, and the results are shown in Table 4.

[0132] [Table 4]

[0133] [Example 55] [Polymerization Example 24 of Polyester Polycarbonate Polyol] A polyester polycarbonate polyol was synthesized in the same manner as in Example 3, except that 0.11 g of zirconium tetra-n-butoxide was added as a catalyst instead of titanium tetra-n-butoxide. The obtained polyester polycarbonate polyol appeared as a viscous liquid, had a hydroxyl value of 55.2 mg KOH / g, and copolymerization proportions of 35.6 mol% of carbonate structures derived from 1,4-butanediol, 35.9 mol% of carbonate structures derived from 1,6-hexanediol, and 28.5 mol% of ester structures derived from adipic acid, with a carbonate group content of 26.6 mass%.

[0134] [Example 56] [Polymerization Example 25 of Polyester Polycarbonate Polyol] A 2L glass flask equipped with a rectification column filled with structured packing and a stirrer was charged with 221g (2.51mol) of ethylene carbonate, 148g (1.64mol) of 1,4-butanediol, 195g (1.65mol) of 1,6-hexanediol, and 122g (0.84mol) of adipic acid. 0.50g of magnesium di-n-butoxide was added as a catalyst, and the reaction was carried out for 24 hours while the reaction temperature was raised to 150-170°C and the pressure was lowered from 10kPa to 3kPa, distilling off the resulting water and a mixture of ethylene glycol and ethylene carbonate. Thereafter, the reaction was switched to simple distillation, and the pressure was gradually reduced to 0.1 kPa while the reaction was carried out at 170° C. for 20 hours to distill off the monomer. The appearance of the obtained polyester polycarbonate polyol was a viscous liquid, and the hydroxyl value was 59.2 mgKOH / g. The copolymerization proportions were 36.6 mol% of carbonate structures derived from 1,4-butanediol, 34.1 mol% of carbonate structures derived from 1,6-hexanediol, and 29.3 mol% of ester structures derived from adipic acid, resulting in a carbonate group content of 26.3 mass%. [Comparative Example 20] [Polymerization Example 26 of Polyester Polycarbonate Polyol] A polyester polycarbonate polyol was synthesized in the same manner as in Example 3, except that 0.06 g of magnesium acetate tetrahydrate was added instead of titanium tetra-n-butoxide as a catalyst. The reaction was carried out at a reaction temperature of 150 to 170°C and a pressure of 3 kPa, but no distillate was produced and the reaction did not proceed, so it was terminated. [Industrial Applicability]

[0135] Polyurethanes using the polyester polycarbonate polyols of the present invention have an excellent balance of flexibility, chemical resistance, low-temperature properties, heat resistance, adhesiveness, abrasion resistance, and tactile feel, and are therefore particularly suitable for use in synthetic leather. The polyester polycarbonate polyol of the present embodiment is also used as a laminating adhesive for various films, a surface protective agent, and the like. [Explanation of symbols]

[0136] 1 Release paper 2 Epidermal layer 3 Adhesive layer 4 Base material (nonwoven fabric) 5 Mixing head (skin layer) 6 Mixing head (adhesive layer) 7 Seat structure (dry synthetic leather product) 8 Coating roll 9. Crimping Roll 10 Winding roll 11 Dryer

Claims

1. The polymer has a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2), has a hydroxyl group at the molecular terminal, has a hydroxyl value of 37 to 86 mgKOH / g, and has a carbonate group content of 15 to 40 mass%, 50 mol % or more of the repeating units represented by formula (1) contain at least two repeating units selected from the group consisting of formula (3), formula (4), and formula (5). Polyester polycarbonate polyol. 【Chemistry 1】 (In formula (1), R 1 is a divalent linear aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms. 【Chemistry 2】 (In formula (2), R 2 is a divalent hydrocarbon having 2 to 4 carbon atoms, R 3 is a divalent linear aliphatic or alicyclic hydrocarbon having 2 to 15 carbon atoms. 【Transformation 3】 【Chemistry 4】 【Transformation 5】

2. 2. The polyester polycarbonate polyol according to claim 1, wherein the molar ratio of the structural unit represented by formula (1) to the structural unit represented by formula (2) is 50 / 50 to 95 / 5.

3. 2. The polyester polycarbonate polyol according to claim 1, wherein 50 mol % or more of the repeating units represented by formula (1) contain repeating units represented by formula (4) and formula (5).

4. 2. The polyester polycarbonate polyol according to claim 1, wherein 50 mol % or more of the repeating units represented by formula (1) contain repeating units of formula (3) and formula (5), and the carbonate group content is 21 to 40 mass %.

5. A synthetic leather produced using the polyester polycarbonate polyol according to any one of claims 1 to 4.

6. 3. The method for producing the polyester polycarbonate polyol according to claim 1, wherein a metal alkoxide is used as a catalyst.

7. 7. The method for producing a polyester polycarbonate polyol according to claim 6, wherein the metal alkoxide is an alkoxide of a metal of Group 4 of the periodic table.

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