Wet film-forming material

Abstract

To solve the problem, the present application provides a wet film-forming material using a bio-based raw material and having excellent wet film-forming properties and hydrolysis resistance. The wet film-forming material of the present application is a wet film-forming material containing a polyurethane resin composition of a polyurethane resin (X) using a polyol (A) and a polyisocyanate (B) as raw materials, and an organic solvent (Y). The polyol (A) contains a bio-based polyester polyol (A-1), and the polyisocyanate (B) contains an aromatic polyisocyanate. The bio-based polyester polyol (A-1) is a polyester polyol using a bio-based diethylene glycol and a bio-based sebacic acid as raw materials.

Description

Technical Field

[0001] This invention relates to a wet film-forming material of a polyurethane resin composition. Background Technology

[0002] Polyurethane resin compositions have long been used in various applications, such as adhesives, coatings, and molding materials, because they can form films with good softness and strength. Among these applications, polyurethane resin compositions, due to their excellent soft feel, are preferably used in the manufacture of porous materials, such as the middle or outer layer of leather-like sheets, for clothing, breathable and waterproof materials, and abrasive pads.

[0003] From the viewpoint of reducing environmental impact, a wet process that allows for easy recovery of organic solvents is known as a method for manufacturing porous materials using the aforementioned polyurethane resin composition. For example, a method for manufacturing a wet-process waterproof fabric is known by coating a resin mixture containing a breathable and waterproof processing urethane resin, dimethylformamide, and a crosslinking agent onto a substrate and then impregnating it in a 10% aqueous solution of dimethylformamide to allow it to solidify (see, for example, Patent Document 1). As a wet-film-forming urethane resin composition, a urethane resin composition is disclosed that uses a urethane resin obtained by reacting a polyol containing an aliphatic polyester polyol with a polyisocyanate containing an aromatic polyisocyanate, and further contains a carbodiimide compound and an organic solvent (see, for example, Patent Document 2).

[0004] On the other hand, against the backdrop of global warming and the depletion of oil resources, the demand for environmentally friendly materials using bio-based raw materials such as plants is increasing worldwide. By using bio-based raw materials, the use of fossil resources such as oil can be reduced, thus contributing to the formation of a sustainable society. This has led to increased demands for the development of sustainable products, including those using bio-based raw materials in synthetic leather. However, currently, wet film-forming materials using bio-based raw materials have not yet been developed.

[0005] [Existing Technical Documents]

[0006] [Patent Literature]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2007-169486

[0008] [Patent Document 2] Japanese Patent Application Publication No. 2012-102182 Summary of the Invention

[0009] [The problem the invention aims to solve]

[0010] The problem to be solved by the present invention is to provide a wet film-forming material of a polyurethane resin composition that uses bio-based raw materials and has excellent wet film-forming properties and hydrolysis resistance.

[0011] [Technical means to solve the problem]

[0012] The present invention provides the following embodiments.

[0013] [1] A wet film-forming material is a wet film-forming material of a polyurethane resin composition, wherein the polyurethane resin composition contains a polyurethane resin (X) made from a polyol (A) and a polyisocyanate (B), and an organic solvent (Y), wherein the wet film-forming material is characterized in that...

[0014] The polyol (A) contains a bio-based polyester polyol (A-1), and the polyisocyanate (B) contains an aromatic polyisocyanate.

[0015] The bio-based polyester polyol (A-1) is made from diol compounds and bio-based sebacic acid.

[0016] The diol compound includes bio-based diethylene glycol.

[0017] [2] According to the wet film-forming material of [1], wherein the content of the bio-based diethylene glycol in the diol compound is more than 15% by mass and less than 100% by mass.

[0018] [3] The wet film-forming material according to [1] or [2], wherein the raw material of the polyurethane resin (X) further comprises a chain elongating agent.

[0019] [4] The wet film-forming material according to [3], wherein the chain elongating agent is at least one selected from the group consisting of ethylene glycol, 1,4-butanediol and 1,3-propanediol.

[0020] [5] The wet film-forming material according to any one of [1] to [4], wherein the polyisocyanate (B) is diphenylmethane diisocyanate.

[0021] [The effects of the invention]

[0022] The wet film-forming material of the present invention uses a polyurethane resin composition made from bio-based raw materials, which is an environmentally friendly material. Furthermore, the polyurethane resin composition exhibits excellent wet film-forming properties and hydrolysis resistance.

[0023] Therefore, the polyurethane resin composition of the present invention can preferably be used as a material in the manufacture of synthetic leather, clothing, support pads, abrasive pads, etc., and can be particularly preferably used as a material for synthetic leather. Detailed Implementation

[0024] (Terminology Explanation)

[0025] In this specification, "bio-based" refers to products made from plant-based materials such as sugarcane, corn, or castor oil.

[0026] (Wet film-forming agents)

[0027] The wet film-forming material of this embodiment is the wet film-forming material of the polyurethane resin composition of this embodiment.

[0028] [Polyurethane Resin Composition]

[0029] The polyurethane resin composition of this embodiment contains the polyurethane resin (X) of this embodiment and an organic solvent (Y).

[0030] <Polyurethane Resin (X)>

[0031] The polyurethane resin (X) of this embodiment is a polyurethane resin made from polyol (A) and polyisocyanate (B). That is, it is a polyurethane resin obtained by reacting polyol (A) with polyisocyanate (B). The polyurethane resin (X) of this embodiment is preferably a polyurethane resin made from polyol (A), a chain extender, and polyisocyanate (B). That is, it is preferably a polyurethane resin obtained by reacting polyol (A), a chain extender, and polyisocyanate (B).

[0032] The polyol (A) of this embodiment is characterized in that it contains a bio-based polyester polyol (A-1), wherein the bio-based polyester polyol (A-1) is made from a diol compound and bio-based sebacic acid, wherein the diol compound includes bio-based diethylene glycol.

[0033] [Polyol (A)]

[0034] The polyol (A) in this embodiment contains a bio-based polyester polyol (A-1).

[0035] The content of the bio-based polyester polyol (A-1) in the polyol (A) is preferably in the range of 10% to 100% by mass, more preferably in the range of 20% to 100% by mass, in order to obtain even better wet film-forming properties.

[0036] The content of the bio-based polyester polyol (A-1) in the raw material of the polyurethane resin (X) is preferably in the range of 10% to 95% by mass, more preferably in the range of 20% to 95% by mass, in order to obtain even better wet film-forming properties.

[0037] "Bio-based Polyester Polyol (A-1)"

[0038] The bio-based polyester polyol (A-1) of this embodiment is a polyester polyol obtained by reacting a diol compound with bio-based sebacic acid. Specifically, it is a polyester polyol obtained by reacting a diol compound with bio-based sebacic acid. The diol compound includes bio-based diethylene glycol.

[0039] As the bio-based polyester polyol (A-1) using the aforementioned diol compound as a raw material, for example, a polyol obtained by subjecting a diol compound containing bio-based diethylene glycol to a known esterification reaction with bio-based sebacic acid can be used. As the bio-based diethylene glycol of this embodiment, for example, a substance obtained from waste molasses such as sugarcane using known methods can be used.

[0040] As a specific example of the aforementioned bio-based diethylene glycol, one could cite "Bio DEG" manufactured by India Glycols.

[0041] Other diol compounds that can be used besides the bio-based diethylene glycol include, for example: bio-based ethylene glycol, bio-based 1,3-propanediol, petroleum-derived diethylene glycol, petroleum-derived ethylene glycol, propylene glycol, petroleum-derived 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentanediol, and 1,6-hexanediol. Alcohols, 1,5-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,8-nonanediol, 2-ethyl-2-butyl-1,3-propanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,3-cyclohexanediol, trimethylolpropane, trimethylolethane, glycerol, ε-caprolactone, etc. These compounds can be used alone or in combination of two or more. Bio-based ethylene glycol and bio-based 1,3-propanediol are particularly preferred.

[0042] The diol compound containing the bio-based diethylene glycol is preferably a bio-based diethylene glycol.

[0043] When the bio-based diethylene glycol is used in conjunction with the other diol compounds, the amount of bio-based diethylene glycol used is preferably 5 mol% or more in the total diol compounds, more preferably 7 mol% or more, and even more preferably 10 mol% or more. Alternatively, the content of bio-based diethylene glycol in the diol compounds is preferably 15% by mass or more and 100% by mass or less, more preferably 30% by mass or more and 100% by mass or less, and even more preferably 50% by mass or more and 100% by mass or less.

[0044] In addition to the bio-based sebacic acid of this embodiment, other polyacids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and their anhydrides can be used. These polyacids can be used alone or in combination of two or more.

[0045] The other polybasic acids are preferably bio-based polybasic acids. Succinic acid, dimer acids, 2,5-furandicarboxylic acid, etc., can be used as bio-based polybasic acids. These compounds can be used alone or in combination of two or more.

[0046] As the bio-based sebacic acid in this embodiment, for example, bio-based sebacic acid obtained by pyrolysis of vegetable oils such as castor oil using a known caustic alkali reaction can be used. As the bio-based succinic acid, for example, bio-based succinic acid obtained by fermenting corn, sugarcane, cassava, sago, etc., using known methods can be used. As the bio-based dimer acid, for example, bio-based dimer acid obtained by dimerizing unsaturated fatty acids from natural plant oils using known methods can be used. As the bio-based 2,5-furandicarboxylic acid, for example, bio-based 2,5-furandicarboxylic acid derived from fructose can be used; bio-based 2,5-furandicarboxylic acid obtained by using furan carboxylic acid, a furfural derivative, and carbon dioxide using known methods can also be used.

[0047] As a specific example of the aforementioned bio-based sebacic acid, one could cite "Bio Seb" manufactured by Toyok Oil.

[0048] The number average molecular weight of the bio-based polyester polyol (A-1) is preferably in the range of 400 to 6000, more preferably in the range of 500 to 5000, and even more preferably in the range of 700 to 3000, for obtaining further superior wet film-forming properties and hydrolysis resistance. Furthermore, the number average molecular weight of the bio-based polyester polyol (A-1) is expressed as a value determined by gel permeation chromatography (GPC).

[0049] As a preferred bio-based polyester polyol (A-1), examples include the reaction product of "Bio DEG" manufactured by India Glycols and "Bio Seb" manufactured by Fengguo Oil.

[0050] As the polyol (A), other polyols may be used in combination besides the bio-based polyester polyol (A-1). Examples of these other polyols include polycarbonate diol, polyether polyol, polybutadiene polyol, and polyester polyols other than the bio-based polyester polyol (A-1). These polyols may be used alone or in combination of two or more.

[0051] The number average molecular weight of the other polyols is preferably in the range of 200 to 100,000, more preferably in the range of 300 to 10,000, for obtaining further superior wet film-forming properties and hydrolysis resistance. Furthermore, the number average molecular weight of the other polyols is expressed as a value determined by gel permeation chromatography (GPC).

[0052] [Chain elongating agent]

[0053] In the polyol (A), a chain elongating agent (a) with a molecular weight in the range of 50 to 450 may be used as needed.

[0054] As the chain elongating agent (a), for example, chain elongating agents containing hydroxyl groups such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylenediol, trimethylolpropane, and glycerol can be used; chain elongating agents containing amino groups such as ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, isophorone diamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine, aminoethylethanolamine, hydrazine, diethylenetriamine, and triethylenetetramine can be used. These chain elongating agents can be used alone or in combination of two or more. Among these, chain extenders having hydroxyl groups are preferred for further improving wet film-forming properties and hydrolysis resistance, and more preferably ethylene glycol, 1,3-propanediol, or 1,4-butanediol. Bio-based ethylene glycol and bio-based 1,3-propanediol can be used as ethylene glycol and 1,3-propanediol.

[0055] In terms of further improving wet film-forming properties and hydrolysis resistance when using the chain elongating agent (a), the amount of the agent is preferably in the range of 0.1% to 50% by mass, and more preferably in the range of 1% to 30% by mass, of the total mass of the raw materials constituting the polyurethane resin (X).

[0056] [Polyisocyanate]

[0057] As for polyisocyanate (B), aromatic polyisocyanates are included to obtain excellent wet film-forming properties. Examples of such aromatic polyisocyanates include: 1,3-phenylene diisocyanate and 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2,5-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylphenylene diisocyanate, and diisopropylphenylene diisocyanate. Isocyanates, including 1-methyl-3,5-diethylphenyl diisocyanate, 3-methyl-1,5-diethylphenyl-2,4-diisocyanate, 1,3,5-triethylphenyl-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinathyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, biphenyl-4,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and diphenylmethane-2,4-diisocyanate, etc. These compounds can be used alone or in combination of two or more. Of these, diphenylmethane diisocyanate is preferred in terms of achieving even better wet film-forming properties and hydrolysis resistance.

[0058] The content of the aromatic polyisocyanate in the polyisocyanate (B) is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0059] The polyisocyanate (B) may be used in combination with other polyisocyanates as needed. Other polyisocyanates mentioned above may include, for example, tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethyl diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclopentanediisocyanate, 1,3-cyclohexanediisocyanate, 1,4-cyclohexanediisocyanate, 1,3-di(isocyanatomethyl)cyclohexane, 1,4-di(isocyanatomethyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate, and other aliphatic or alicyclic polyisocyanates. These polyisocyanates may be used alone or in combination of two or more.

[0060] Regarding the amount of polyisocyanate (B) used, in order to obtain even better wet film-forming properties and hydrolysis resistance, the total mass of the raw materials constituting the polyurethane resin (X) is preferably in the range of 10% to 60% by mass, and more preferably in the range of 15% to 45% by mass.

[0061] In particular, when the aromatic polyisocyanate contained in the polyisocyanate (B) is diphenylmethane diisocyanate, the content of diphenylmethane diisocyanate in the raw material of the polyurethane resin (X) of this embodiment is preferably 10% by mass or more and 60% by mass or less, more preferably 10% by mass or more and 55% by mass or less.

[0062] [Manufacturing method of polyisocyanate resin]

[0063] As a method for manufacturing the polyurethane resin (X), examples include a method of adding the polyol (A), a chain elongating agent as needed, and the polyisocyanate (B) in a single step and reacting them, for example, the reaction is preferably carried out at a temperature of 30°C to 100°C for 3 to 10 hours. Alternatively, the reaction can be carried out in an organic solvent (Y) described later.

[0064] The number average molecular weight of the polyurethane resin (X) obtained by the above method is preferably in the range of 5,000 to 1,000,000, and more preferably in the range of 10,000 to 500,000, which can further improve the abrasion resistance, oleic acid resistance, low-temperature bending resistance, mechanical strength of the film, and flexibility. Furthermore, the number average molecular weight of the polyurethane resin (X) is a value determined by gel permeation chromatography (GPC).

[0065] The content of the polyurethane resin (X) in the polyurethane resin composition is preferably in the range of 10% to 90% by mass, and more preferably in the range of 15% to 80% by mass.

[0066] <Organic Solvents>

[0067] As the organic solvent (Y) in this embodiment, for example, ketone solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, methyl ethyl ketone, methyl n-propyl ketone, acetone, and methyl isobutyl ketone can be used; ester solvents such as methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, isopropyl acetate, isobutyl acetate, and sec-butyl acetate can be used; alcohol solvents such as methanol, ethanol, isopropanol, and butanol can be used; etc. These organic solvents can be used alone or in combination of two or more.

[0068] The content of the organic solvent (Y) in the polyurethane resin composition is preferably in the range of 20% to 90% by mass, more preferably in the range of 40% to 80% by mass, in terms of workability and viscosity.

[0069] <Other Ingredients>

[0070] The polyurethane resin composition contains the polyurethane resin (X) and the organic solvent (Y) as essential components, but may also contain other components as needed.

[0071] Other components may include, for example, pigments, flame retardants, plasticizers, softeners, stabilizers, waxes, defoamers, dispersants, penetrants, surfactants, fillers, mildew inhibitors, antibacterial agents, UV absorbers, antioxidants, weather stabilizers, fluorescent whitening agents, anti-aging agents, and thickeners. These components may be used alone or in combination of two or more.

[0072] [Preparation method of polyurethane resin composition]

[0073] Examples of methods for preparing the polyurethane resin composition of this embodiment include: using the polyurethane resin composition directly in solution without separating it, and adding an organic solvent (Y) as needed to prepare a polyurethane resin composition with a predetermined composition. The organic solvent (Y) added to the polyurethane resin composition may be the same as or different from the organic solvent used in manufacturing the polyurethane resin. Preferably, the organic solvent (Y) added to the polyurethane resin composition is the same as the organic solvent used in manufacturing the polyurethane resin.

[0074] [Method for manufacturing wet-film-forming materials (porous materials)]

[0075] Next, a method for manufacturing the wet film-forming material (porous body) of this embodiment by means of the polyurethane resin composition using a wet film-forming method will be described.

[0076] The wet film-forming method refers to a method of coating or impregnating the polyurethane resin composition onto the surface of a substrate, and then bringing water or water vapor into contact with the coated or impregnated surface, thereby causing the polyurethane resin (A) to solidify and produce a porous body.

[0077] As a substrate for coating the polyurethane resin composition, for example, a substrate comprising nonwoven fabric, woven fabric, or braided fabric can be used; a resin film, etc. As materials constituting the substrate, for example, chemical fibers such as polyester fiber, nylon fiber, acrylic fiber, polyurethane fiber, acetate fiber, rayon fiber, polylactic acid fiber, etc.; cotton, linen, silk, wool, and their blended fibers, etc., can be used.

[0078] The surface of the substrate may also be treated as needed, such as antistatic processing, demolding processing, water-repellent processing, water-absorbing processing, antibacterial and deodorizing processing, bactericidal processing, and ultraviolet blocking processing.

[0079] Methods for coating or impregnating the polyurethane resin composition onto the substrate surface include, for example, gravure coating, blade coating, tube coating, and corner wheel coating. In this case, the amount of organic solvent (Y) used can be adjusted as needed to improve the workability of the coating by adjusting the viscosity of the polyurethane resin composition.

[0080] The thickness of the coating film comprising the polyurethane resin composition applied or impregnated by the method is preferably in the range of 0.5 mm to 5 mm, more preferably in the range of 0.5 mm to 3 mm.

[0081] Methods for bringing water or water vapor into contact with the coated surface formed by coating or impregnating the polyurethane resin composition include, for example, immersing a substrate having a coating layer or impregnated layer containing the polyurethane resin composition in a water bath; or spraying water onto the coated surface using a sprayer or similar method. The immersion is preferably performed in a water bath at 5°C to 60°C for approximately 2 to 20 minutes.

[0082] For the wet film-forming material obtained by the method, it is preferable to wash its surface with room temperature or warm water to extract and remove the organic solvent (Y), followed by drying. The washing is preferably performed using water at 5°C to 60°C for approximately 20 to 120 minutes, and the water used for washing is preferably changed more than once, or continuously changed using running water. The drying is preferably performed using a dryer or similar device adjusted to 80°C to 120°C for approximately 10 to 60 minutes.

[0083] [Example]

[0084] The following examples illustrate this implementation in more detail.

[0085] [Synthesis example 1]

[0086] Synthesis of Polyester Polyols

[0087] In a four-necked flask including a thermometer, a stirrer, an inert gas inlet, and a reflux cooler, 187 parts by mass of bio-based sebacic acid (Bio Seb) and 113 parts by mass of bio-based diethylene glycol (Bio DEG) were added. Relative to the total amount added, 0.01% of tetraisopropyl titanate as an esterification catalyst was added. The reaction was carried out at 220°C for 15 hours to obtain bio-based polyester polyol PA1.

[0088] The obtained bio-based polyester polyol had an acid value of 0.54 mgKOH / g and a hydroxyl value of 55.6 mgKOH / g. The results are shown in Table 1.

[0089] Furthermore, the acid value of the bio-based polyester polyol was determined according to Japanese Industrial Standard (JIS) K1557-5. The hydroxyl value of the bio-based polyester polyol was determined according to JIS K0070.

[0090] [Synthesis Examples 2-4, Comparison Synthesis Examples 1-2]

[0091] Based on the raw materials and blending ratios (unit: parts by mass) shown in Table 1, bio-based polyester polyols PA2 to PA4, and polyester polyols cPA1 to cPA2 were obtained using the same method as in Synthesis Example 1. Furthermore, the acid value and hydroxyl value of the polyester polyols were evaluated using the same evaluation method. The results are shown in Table 1.

[0092] [Table 1]

[0093]

[0094] Explanation of symbols in Table 1:

[0095] Bio DEG: Bio-based diethylene glycol (manufactured by India Glycols)

[0096] Bio 1,3-PDO: Bio-based 1,3-propanediol (manufactured by DuPont) Bio EG: Bio-based ethylene glycol (manufactured by India Glycols) EG: Ethylene glycol (manufactured by Mitsubishi Chemical)

[0097] BG: Butanediol (manufactured by Mitsubishi Chemical)

[0098] Bio Seb: Bio-based sebacic acid (manufactured by Fengguo Oil Company)

[0099] DEG: Diethylene glycol (manufactured by Mitsubishi Chemical)

[0100] AA: Adipic acid (manufactured by Asahi Kasei)

[0101] [Example 1]

[0102] <Preparation of Polyurethane Resin Compositions>

[0103] In a four-necked flask including a stirrer, reflux cooling tube, thermometer, and nitrogen inlet tube, under a nitrogen flow, 280 parts by mass of the bio-based polyester polyol PA1 (number average molecular weight 2000) obtained in Synthesis Example 1, 16 parts by mass of ethylene glycol (EG), and 930 parts by mass of N,N-dimethylformamide were added and thoroughly stirred. After stirring and mixing, 100 parts by mass of methylenediphenyl diisocyanate (MDI) were added, and the mixture was reacted at 80°C for 3 hours to obtain a polyurethane resin solution with a solid content of 30% and a viscosity of 900 dPa·s, as the polyurethane resin composition.

[0104] <Preparation of wet film-forming materials>

[0105] The prepared solution obtained by diluting the polyurethane resin composition with 60 parts by weight of N,N-dimethylformamide (DMF) was applied to the polyethylene terephthalate film with a gap of 1 mm. Then, it was immersed in water at 25°C for 10 minutes, washed with warm water at 40°C for 1 hour, and dried in a dryer at 100°C for 30 minutes to obtain a wet film.

[0106] The wet film-forming properties and hydrolysis resistance of the obtained wet film-forming materials were evaluated using the evaluation methods described later, and the results are shown in Table 2.

[0107] [Example 2]

[0108] <Preparation of Polyurethane Resin Compositions>

[0109] In a four-necked flask including a stirrer, reflux cooling tube, thermometer, and nitrogen inlet tube, under a nitrogen flow, 280 parts by mass of the bio-based polyester polyol PA2 (number average molecular weight 2000) obtained in Synthesis Example 2, 16 parts by mass of ethylene glycol (EG), and 930 parts by mass of N,N-dimethylformamide were added and thoroughly stirred. After stirring and mixing, 100 parts by mass of diphenylmethane diisocyanate (MDI) were added, and the mixture was reacted at 80°C for 3 hours to obtain a polyurethane resin solution with a solid content of 30% and a viscosity of 900 dPa·s, which was used as the polyurethane resin composition.

[0110] <Preparation of wet film-forming materials>

[0111] Except for using the obtained polyurethane resin composition, wet film-forming materials were prepared using the same method as in Example 1, and the obtained wet film-forming materials were evaluated using the same method as in Example 1. The results are shown in Table 2.

[0112] [Example 3]

[0113] <Preparation of Polyurethane Resin Compositions>

[0114] In a four-necked flask including a stirrer, reflux cooling tube, thermometer, and nitrogen inlet tube, under a nitrogen flow, 280 parts by mass of the bio-based polyester polyol PA3 (number average molecular weight 2000) obtained in Synthesis Example 3, 16 parts by mass of ethylene glycol (EG), and 930 parts by mass of N,N-dimethylformamide were added and thoroughly stirred. After stirring and mixing, 100 parts by mass of diphenylmethane diisocyanate (MDI) were added, and the mixture was reacted at 80°C for 3 hours to obtain a polyurethane resin solution with a solid content of 30% and a viscosity of 900 dPa·s, which was used as the polyurethane resin composition.

[0115] <Preparation of wet film-forming materials>

[0116] Except for using the obtained polyurethane resin composition, wet film-forming materials were prepared using the same method as in Example 1, and the obtained wet film-forming materials were evaluated using the same method as in Example 1. The results are shown in Table 2.

[0117] [Example 4]

[0118] <Preparation of Polyurethane Resin Compositions>

[0119] In a four-necked flask including a stirrer, reflux cooling tube, thermometer, and nitrogen inlet tube, under a nitrogen flow, 280 parts by mass of the bio-based polyester polyol PA1 (number average molecular weight 2000) obtained in Synthesis Example 1, 16 parts by mass of bio-based ethylene glycol (BioEG), and 930 parts by mass of N,N-dimethylformamide were added and thoroughly mixed. After mixing, 100 parts by mass of diphenylmethane diisocyanate (MDI) were added, and the mixture was reacted at 80°C for 3 hours to obtain a polyurethane resin solution with a solid content of 30% and a viscosity of 900 dPa·s, which served as the polyurethane resin composition.

[0120] <Preparation of wet film-forming materials>

[0121] Except for using the obtained polyurethane resin composition, wet film-forming materials were prepared using the same method as in Example 1, and the obtained wet film-forming materials were evaluated using the same method as in Example 1. The results are shown in Table 2.

[0122] [Example 5]

[0123] <Preparation of Polyurethane Resin Compositions>

[0124] In a four-necked flask including a stirrer, reflux cooling tube, thermometer, and nitrogen inlet tube, under a nitrogen flow, 280 parts by mass of the bio-based polyester polyol PA1 (number average molecular weight 2000) obtained in Synthesis Example 1, 16 parts by mass of bio-based 1,3-propanediol (Bio 1,3-PDO), and 930 parts by mass of N,N-dimethylformamide were added and thoroughly mixed. After mixing, 100 parts by mass of diphenylmethane diisocyanate (MDI) were added, and the mixture was reacted at 80°C for 3 hours to obtain a polyurethane resin solution with a solid content of 30% and a viscosity of 900 dPa·s, which served as the polyurethane resin composition.

[0125] <Preparation of wet film-forming materials>

[0126] Except for using the obtained polyurethane resin composition, wet film-forming materials were prepared using the same method as in Example 1, and the obtained wet film-forming materials were evaluated using the same method as in Example 1. The results are shown in Table 2.

[0127] [Example 6]

[0128] <Preparation of Polyurethane Resin Compositions>

[0129] In a four-necked flask including a stirrer, reflux cooling tube, thermometer, and nitrogen inlet tube, under a nitrogen flow, 140 parts by mass of the bio-based polyester polyol PA1 (number average molecular weight 2000) obtained in Synthesis Example 1, 140 parts by mass of the bio-based polyester polyol PA4 (number average molecular weight 2000) obtained in Synthesis Example 4, 16 parts by mass of ethylene glycol (EG), and 930 parts by mass of N,N-dimethylformamide were added and thoroughly stirred. After stirring and mixing, 100 parts by mass of diphenylmethane diisocyanate (MDI) were added, and the mixture was reacted at 80°C for 3 hours to obtain a polyurethane resin solution with a solid content of 30% and a viscosity of 900 dPa·s, which was used as the polyurethane resin composition.

[0130] <Preparation of wet film-forming materials>

[0131] Except for using the obtained polyurethane resin composition, wet film-forming materials were prepared using the same method as in Example 1, and the obtained wet film-forming materials were evaluated using the same method as in Example 1. The results are shown in Table 2.

[0132] [Comparative Example 1]

[0133] <Preparation of Polyurethane Resin Compositions>

[0134] In a four-necked flask including a stirrer, reflux cooling tube, thermometer, and nitrogen inlet tube, under a nitrogen flow, 280 parts by mass of polyester polyol cPA1 (number average molecular weight 2000), 16 parts by mass of ethylene glycol (EG), and 930 parts by mass of N,N-dimethylformamide obtained in Comparative Synthesis Example 1 were added and thoroughly stirred. After stirring and mixing, 100 parts by mass of diphenylmethane diisocyanate (MDI) were added, and the mixture was reacted at 80°C for 3 hours to obtain a polyurethane resin solution with a solid content of 30% and a viscosity of 900 dPa·s, which was used as the polyurethane resin composition.

[0135] <Preparation of wet film-forming materials>

[0136] Except for using the obtained polyurethane resin composition, wet film-forming materials were prepared using the same method as in Example 1, and the obtained wet film-forming materials were evaluated using the same method as in Example 1. The results are shown in Table 2.

[0137] [Comparative Example 2]

[0138] <Preparation of Polyurethane Resin Compositions>

[0139] In a four-necked flask including a stirrer, reflux cooling tube, thermometer, and nitrogen inlet tube, under a nitrogen flow, 280 parts by mass of polyester polyol cPA2 (number average molecular weight 2000), 16 parts by mass of ethylene glycol (EG), and 930 parts by mass of N,N-dimethylformamide obtained in Comparative Synthesis Example 2 were added and thoroughly mixed. After mixing, 100 parts by mass of diphenylmethane diisocyanate (MDI) were added, and the mixture was reacted at 80°C for 3 hours to obtain a polyurethane resin solution with a solid content of 30% and a viscosity of 900 dPa·s, which was used as the polyurethane resin composition.

[0140] <Preparation of wet film-forming materials>

[0141] Except for using the obtained polyurethane resin composition, wet film-forming materials were prepared using the same method as in Example 1, and the obtained wet film-forming materials were evaluated using the same method as in Example 1. The results are shown in Table 2.

[0142] [Comparative Example 3]

[0143] <Preparation of Polyurethane Resin Compositions>

[0144] In a four-necked flask including a stirrer, reflux cooling tube, thermometer, and nitrogen inlet tube, under a nitrogen flow, 280 parts by mass of the bio-based polyester polyol PA4 (number average molecular weight 2000) obtained in Synthesis Example 4, 16 parts by mass of ethylene glycol (EG), and 930 parts by mass of N,N-dimethylformamide were added and thoroughly mixed. After mixing, 100 parts by mass of diphenylmethane diisocyanate (MDI) were added, and the mixture was reacted at 80°C for 3 hours to obtain a polyurethane resin solution with a solid content of 30%, which was used as the polyurethane resin composition.

[0145] <Preparation of wet film-forming materials>

[0146] Except for using the obtained polyurethane resin composition, wet film-forming materials were prepared using the same method as in Example 1, and the obtained wet film-forming materials were evaluated using the same method as in Example 1. The results are shown in Table 2.

[0147] [Method for determining number-average molecular weight]

[0148] The number-average molecular weights of polyols, etc., used in the examples and comparative examples are values ​​obtained by gel permeation chromatography (GPC) under the following conditions.

[0149] Measurement device: High-speed GPC device (HLC-8220GPC manufactured by Tosoh Corporation)

[0150] Tube Column: The following tube columns manufactured by Tosoh Corporation are connected in series for use.

[0151] "TSKgel G5000" (7.8mm I.D. × 30cm) × 1 stick

[0152] "TSKgel G4000" (7.8mm I.D. × 30cm) × 1 stick

[0153] "TSKgel G3000" (7.8mm I.D. × 30cm) × 1 stick

[0154] "TSKgel G2000" (7.8mm I.D. × 30cm) × 1 stick

[0155] Detector: RI (Differential Refractometer)

[0156] Column temperature: 40℃

[0157] Dissolution solution: Tetrahydrofuran (THF)

[0158] Flow rate: 1.0 mL / min

[0159] Injection volume: 100 μL (a tetrahydrofuran solution with a sample concentration of 0.4% by mass)

[0160] Standard sample: Calibration curves were prepared using the standard polystyrene described below.

[0161] (Standard polystyrene)

[0162] "TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation

[0163] "TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation

[0164] "TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation

[0165] "TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation

[0166] "TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation

[0167] "TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation

[0168] "TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation

[0169] "TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation

[0170] "TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation

[0171] "TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation

[0172] "TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation

[0173] "TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation

[0174] "TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation

[0175] "TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

[0176] [Evaluation Methods for Wet Film-Forming Properties]

[0177] The wet films obtained in the examples and comparative examples were visually observed using a scanning electron microscope "SU3500" (500x magnification) manufactured by Hitachi High Technology Co., Ltd., to confirm whether porous structures were formed. Cases where uniformly shaped pores were confirmed were evaluated as "○", and cases where non-uniform pores were confirmed were evaluated as "×".

[0178] [Evaluation method for hydrolysis resistance]

[0179] The obtained wet film-forming material (synthetic leather) was cured for 3 weeks under humid heat conditions of 70°C and 95%. A condition with no abnormal appearance was rated "○", while a condition exhibiting changes in gloss and a sticky feel was rated "×".

[0180]

[0181] Explanation of symbols in Table 2:

[0182] (A): Polyol (Bio-based Polyester Polyol (A-1))

[0183] (B): Polyisocyanate

[0184] Chex: Chain elongating agent

[0185] MDI: Diphenylmethane diisocyanate (manufactured by Tosoh)

[0186] DMF: N,N-Dimethylformamide (manufactured by Mitsubishi Gas Chemical)

[0187] It can be seen that Examples 1 to 6, which are wet film-forming materials of this embodiment, have excellent wet film-forming properties and hydrolysis resistance. This is believed to be due to the good balance between polarity and hydrophobicity in the polyurethane resin (X).

[0188] On the other hand, Comparative Example 1 used diethylene glycol and adipic acid instead of bio-based diethylene glycol and bio-based sebacic acid, but the hydrolysis resistance was poor. This is believed to be due to the high polarity of the polyurethane resin (X). Comparative Example 2 used butanediol instead of bio-based diethylene glycol, but the wet film-forming properties were poor. This is believed to be due to the strong hydrophobicity of the polyurethane resin (X). Comparative Example 3 used bio-based 1,3-propanediol instead of bio-based diethylene glycol, but the wet film-forming properties were poor.

Claims

1. A wet film-forming material, which is a wet film-forming material of a polyurethane resin composition, said polyurethane resin composition containing a polyurethane resin (X) made from a polyol (A) and a polyisocyanate (B), and an organic solvent (Y), characterized in that, The polyol (A) contains a bio-based polyester polyol (A-1), and the polyisocyanate (B) contains an aromatic polyisocyanate. The bio-based polyester polyol (A-1) is made from diol compounds and bio-based sebacic acid. The diol compound includes bio-based diethylene glycol.

2. The wet film-forming material according to claim 1, wherein, In the diol compound, the content of the bio-based diethylene glycol is 15% by mass or more and 100% by mass or less.

3. The wet film-forming material according to claim 1 or 2, wherein, The raw materials for the polyurethane resin (X) also include chain elongating agents.

4. The wet film-forming material according to claim 3, wherein, The chain elongating agent is at least one selected from the group consisting of ethylene glycol, 1,4-butanediol, and 1,3-propanediol.

5. The wet film-forming material according to claim 1 or 2, wherein, The polyisocyanate (B) is diphenylmethane diisocyanate.

6. The wet film-forming material according to claim 3, wherein, The polyisocyanate (B) is diphenylmethane diisocyanate.

7. The wet film-forming material according to claim 4, wherein, The polyisocyanate (B) is diphenylmethane diisocyanate.

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