JP5554156B2 - imitation leather - Google Patents

Description

  The present invention relates to an artificial leather obtained using a resin composition containing a self-crosslinking polyhydroxypolyurethane resin as a main component. More specifically, it has excellent scratch resistance, abrasion resistance, chemical resistance, and heat resistance, and the resin used as the main component has carbon dioxide fixed in the structure, thus preventing global environmental destruction. It relates to artificial leather that is also useful from a viewpoint.

  Conventionally, artificial leather is used for bags, bags, shoes, furniture, clothing, vehicle interior materials, electrical appliances, etc., and polyurethane-based resins are widely used as the resin for artificial leather. The “pseudo-leather” is a generic name for leather-like products manufactured to resemble natural leather, and is generally roughly classified into artificial leather, synthetic leather, and vinyl chloride leather.

  Artificial leather has a structure most similar to natural leather among artificial leather, but uses non-woven fabric for the base fabric. As a general method for producing artificial leather, there are the following methods. First, a non-woven fabric is impregnated with a dimethylformamide (hereinafter referred to as DMF) solution of a polyurethane resin, and then solidified and dried in a porous state by wet film formation (solidification in water). After that, there are a method in which a polyurethane resin is further coated or laminated on the surface to make it smooth, and a method in which the surface is ground and brushed to make it suede.

  Synthetic leather, on the other hand, uses a fabric such as a woven fabric or a brushed fabric as a base fabric. Generally, synthetic leather is roughly classified into dry synthetic leather and wet synthetic leather. Furthermore, as a method for producing dry synthetic leather, a polyurethane resin is directly applied to the base fabric and dried, and after applying the polyurethane resin on the release paper, it is dried and filmed, and then adhered to the base fabric with an adhesive. There is a way to match. In addition, wet synthetic leather can be produced by impregnating or coating a base fabric with the above-described DMF solution of polyurethane resin, followed by solidification and drying in water to form a porous layer. Furthermore, by applying a polyurethane-based resin or laminating a layer on each surface obtained by the dry or wet methods as described above to make it smooth, or by raising the surface by grinding the surface There is a method of suede tone.

  On the other hand, the global warming phenomenon, which is thought to be caused by the ever-increasing carbon dioxide emissions in recent years, has become a global problem, and the reduction of carbon dioxide emissions is an important issue worldwide. It has become. Furthermore, from the viewpoint of the depleted petrochemical resource (petroleum) problem, conversion to renewable resources such as biomass and methane has become a global trend (Non-Patent Documents 1 and 2).

  Against the background described above, even in the field of artificial leather, there are a number of manufacturers who are actively engaged in environmental measures, and there is a movement to construct artificial leather products using materials with excellent environmental conservation. For example, instead of using a polyurethane-based resin that uses an organic solvent, use a polyurethane resin that can be dispersed or emulsified in an aqueous medium to reduce VOC (volatile organic compound) emissions as much as possible. Therefore, studies on the use of plant-derived raw materials have been actively conducted. However, it can be said that there is a difference in performance as compared with the conventional product and there is a problem in practical use, and it is still insufficient from the viewpoint of realizing current global environmental conservation (Patent Documents 1 to 3). ).

JP 2009-144313 A JP 2007-270373 A JP 2005-154580 A

N. Kihara, T. Endo, J. Org. Chem., 1993, 58, 6198 N. Kihara, T. Endo, J. Polymer Sci., Part A Polmer Chem., 1993, 31 (11), 2765

  Under such circumstances, even for artificial leather, excellent surface-friendly products that contribute to environmental protection measures on a global scale as well as superior surface scratch resistance, abrasion resistance, chemical resistance, and heat resistance. Development is desired.

  Therefore, the object of the present invention is not particularly inferior to the conventional artificial leather, and has excellent surface scratch resistance, abrasion resistance, chemical resistance, and heat resistance, as well as incorporating carbon dioxide into the resin and fixing it. By using artificial materials to manufacture artificial leather, it can contribute to the reduction of carbon dioxide, which is regarded as a global problem as a global warming gas. To provide fake leather.

  The above object is achieved by the present invention described below. That is, the present invention provides a resin composition mainly composed of a self-crosslinking polyhydroxypolyurethane resin having an isocyanate group masked in its structure, which is derived from a reaction between a 5-membered cyclic carbonate compound and an amine compound. The present invention provides an artificial leather characterized by being filled or laminated on a base fabric.

The following are mentioned as a preferable form of this invention. The 5-membered cyclic carbonate compound, a reaction product of an epoxy compound and carbon dioxide, and the self-crosslinking polyhydroxy polyurethane resin, in the structure of their derived from carbon dioxide used in the reaction Said artificial leather which takes in carbon dioxide in the range of 1-25 mass%. The masked isocyanate group is a reaction product of an organic polyisocyanate group and a masking agent, and the masked portion is dissociated by heat treatment to form an isocyanate group. The artificial leather as described above, which reacts with a hydroxyl group in the structure to self-crosslink. The artificial leather as described above, wherein the resin composition further contains another resin.

  According to the present invention, there is no inferiority to conventional artificial leather, excellent surface scratch resistance, abrasion resistance, chemical resistance, and heat resistance, and a material in which carbon dioxide is taken into a resin and fixed is imitated. Useful as an environmentally friendly product from the viewpoint of global environmental conservation that can contribute to the reduction of carbon dioxide, which is regarded as a global problem as a global warming gas. Fake leather is provided.

Next, the present invention will be described in more detail with reference to preferred embodiments.
The artificial leather of the present invention is a resin composition comprising, as a main component, a self-crosslinking polyhydroxypolyurethane resin having an isocyanate group masked in its structure, which is derived from a reaction between a 5-membered cyclic carbonate compound and an amine compound. The base fabric is filled or laminated. The masked isocyanate group of the resin is a reaction product of an organic polyisocyanate group and a masking agent, and the masked portion is dissociated by heat treatment to generate an isocyanate group, thereby producing a self-crosslinked polyhydroxy polyurethane resin. It reacts with a hydroxyl group in the structure and self-crosslinks. For this reason, the use of the resin makes it possible to obtain artificial leather having excellent surface scratch resistance, abrasion resistance, chemical resistance, and heat resistance. A self-crosslinking polyhydroxypolyurethane resin particularly suitable from the viewpoint of global environmental protection used in the present invention is a reaction product of an epoxy compound and carbon dioxide in which a five-membered cyclic carbonate compound has a structure containing carbon dioxide. Carbon is contained in the range of 1 to 25% by mass.

(Self-crosslinking type polyhydroxy polyurethane resin)
The self-crosslinking polyhydroxypolyurethane resin used in the present invention uses a modifier having at least one free isocyanate group and a masked isocyanate group, and the free isocyanate group of the modifier is a 5-membered cyclic ring. It can be easily obtained by reacting with a hydroxyl group in a polyhydroxy polyurethane resin derived from the reaction between a carbonate compound and an amine compound. As a modifier used at this time, a reaction product of an organic polyisocyanate compound and a masking agent may be used. Below, each component is demonstrated.

<Organic polyisocyanate compound>
The organic polyisocyanate compound used in the present invention is a compound having at least two isocyanate groups in an aliphatic or aromatic compound and has been widely used as a raw material for synthesizing polyurethane resins. Any of these known organic polyisocyanate compounds are useful in the present invention. Particularly preferable organic polyisocyanate compounds are as follows.

  1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate), 4,4'-dicyclohexylmethane Examples thereof include diisocyanate, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, and xylylene diisocyanate. Furthermore, adducts of these organic polyisocyanate compounds and other compounds, for example, those having the following structural formulas are exemplified, but not limited thereto.

<Masking agent>
The modifying agent used in the present invention is a reaction product of the organic polyisocyanate compound and the masking agent described above, and the following can be used as the masking agent. Alcohol-based, phenol-based, active methylene-based, acid amide-based, imidazole-based, urea-based, oxime-based, and pyridine-based compounds may be used alone or in combination. Specific masking agents are as follows.

  Examples of alcohols include methanol, ethanol, propanol, butanol, 2-ethylhexanol, methyl cellosolve, and cyclohexanol. Examples of the phenol type include phenol, cresol, ethylphenol, and nonylphenol. Examples of the active methylene group include dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone and the like. Examples of acid amides include acetanilide, acetic acid amide, caprolactam, and γ-butyrolactam. Examples of the imidazole series include imidazole and 2-methylimidazole. Examples of the urea system include urea, thiourea, and ethylene urea. Examples of oximes include formamide oxime, acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime. Examples of pyridine include 2-hydroxypyridine and 2-hydroxyquinoline.

<Method of synthesizing denaturant>
The organic polyisocyanate compound listed above and the masking agent listed above are reacted to synthesize a modifier having at least one free isocyanate group and a masked isocyanate group used in the present invention. Although the synthesis method is not particularly limited, the masking agent as described above and the organic polyisocyanate compound are functional groups in which one or more isocyanate groups are excessive in one molecule, in the presence or absence of an organic solvent and a catalyst. It can be easily obtained by reacting at a temperature of 0 to 150 ° C., preferably 20 to 80 ° C. for 30 minutes to 3 hours.

<Polyhydroxy polyurethane resin>
The polyhydroxypolyurethane resin modified with the specific modifier as described above is obtained by a reaction between a 5-membered cyclic carbonate compound and an amine compound. Below, each component used in this case is demonstrated.

[5-membered cyclic carbonate compound]
The 5-membered cyclic carbonate compound used in the present invention can be produced by reacting an epoxy compound and carbon dioxide as shown by the following [Formula-A]. More specifically, the epoxy compound is carbon dioxide in the presence or absence of an organic solvent and in the presence of a catalyst at a temperature of 40 ° C. to 150 ° C. for 10-20 hours at normal pressure or slightly elevated pressure. It is obtained by reacting with.

  Examples of the epoxy compound that can be used above include the following compounds.

  The epoxy compounds listed above are preferable compounds used in the present invention, and the present invention is not limited to these exemplified compounds. Accordingly, not only the above-exemplified compounds but also any other compounds that are currently commercially available and can be easily obtained from the market can be used in the present invention.

Examples of the catalyst that can be used in the reaction of the above-described epoxy compound and carbon dioxide include a base catalyst and a Lewis acid catalyst.
Base catalysts include tertiary amines such as triethylamine and tributylamine, cyclic amines such as diazabicycloundecene, diazabicyclooctane and pyridine, alkalis such as lithium chloride, lithium bromide, lithium fluoride and sodium chloride. Metal salts, alkaline earth metal salts such as calcium chloride, quaternary ammonium salts such as tetrabutylammonium chloride, tetraethylammonium bromide, benzyltrimethylammonium chloride, carbonates such as potassium carbonate and sodium carbonate, zinc acetate, lead acetate, Examples thereof include metal acetates such as copper acetate and iron acetate, metal oxides such as calcium oxide, magnesium oxide and zinc oxide, and phosphonium salts such as tetrabutylphosphonium chloride.

  Examples of the Lewis acid catalyst include tin compounds such as tetrabutyltin, dibutyltin dilaurate, dibutyltin diacetate, and dibutyltin octoate.

  The amount of the catalyst may be about 0.1 to 100 parts by mass, preferably 0.3 to 20 parts by mass, per 50 parts by mass of the epoxy compound. If the amount used is less than 0.1 parts by mass, the effect as a catalyst is small, and if it exceeds 100 parts by mass, various performances of the final resin may be deteriorated. However, in the case where the residual catalyst causes a serious performance deterioration, it may be configured to be removed by washing with pure water.

  Examples of the organic solvent that can be used in the reaction of the epoxy compound and carbon dioxide include dimethylformamide, dimethylsulfoxide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, and tetrahydrofuran. These organic solvents and other poor solvents such as methyl ethyl ketone, xylene, toluene, tetrahydrofuran, diethyl ether, and cyclohexanone may be used in a mixed system.

  As shown by the following [Formula-B], the polyhydroxypolyurethane resin used in the present invention is obtained by combining a 5-membered cyclic carbonate compound obtained as described above and an amine compound in the presence of an organic solvent. It can obtain by making it react at the temperature of 150 degreeC-150 degreeC.

[Amine compound]
As an amine compound used for the said reaction, a diamine is preferable and what was conventionally used for manufacture of a polyurethane resin can be used, and it is not specifically limited. For example, aliphatic diamines such as methylenediamine, ethylenediamine, trimethylenediamine, 1,3-diaminopropane, hexamethylenediamine, octamethylenediamine; phenylenediamine, 3,3′-dichloro-4,4′-diaminodiphenylmethane, 4 , 4′-methylenebis (phenylamine), 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylsulfone, metaxylylenediamine, paraxylylenediamine, and the like; 1,4-cyclohexanediamine, 4 , 4'-diaminocyclohexylmethane, 1,4'-diaminomethylcyclohexane, isophoronediamine and other alicyclic diamines; monoethanoldiamine, ethylaminoethanolamine and hydroxyethylaminopropylamine Nol diamine is mentioned.

  The amine compounds listed above are preferable compounds used in the present invention, and the present invention is not limited to these exemplified compounds. Accordingly, not only the above-exemplified compounds but also any other compounds that are currently commercially available and can be easily obtained from the market can be used in the present invention.

[Physical properties]
In addition, the polyhydroxy polyurethane resin used in the present invention preferably has a number average molecular weight (standard polystyrene conversion value measured by GPC) of about 2,000 to 100,000, more preferably 5,000 to 70. About 1,000.

  The polyhydroxy polyurethane resin used in the present invention preferably has a hydroxyl value of 20 to 300 mgKOH / g. When the hydroxyl group content is less than the above range, the effect of reducing carbon dioxide is insufficient, while when it exceeds the above range, various physical properties as a polymer compound are insufficient.

<Manufacture of self-crosslinking type polyhydroxy polyurethane resin>
The self-crosslinking polyhydroxypolyurethane resin used in the present invention is obtained by reacting the modifier obtained as described above with a polyhydroxypolyurethane resin. Specifically, it can be obtained by reacting the hydroxyl group in the polyhydroxy polyurethane resin with at least one free isocyanate group in the modifier.

The modification rate of the self-crosslinking polyhydroxypolyurethane resin used in the present invention with a modifier is preferably 2 to 60%. Depending on the ratio of the modification rate, performances such as wear resistance, chemical resistance, and heat resistance after heat treatment can be controlled to some extent, but if the modification rate is less than 2%, sufficient crosslinking will not occur and the production of artificial leather When it is used, it is not preferable because heat resistance, chemical resistance and the like may be insufficient. On the other hand, if the modification rate exceeds 60%, the texture of the artificial leather is impaired by overcrosslinking, and the possibility that the dissociated isocyanate group remains without reacting is not preferable. The modification rate is calculated as follows.
Modification rate (%) = {1− (hydroxyl group of resin after modification ÷ hydroxyl group of resin before modification)} × 100

  The reaction between the modifier and the polyhydroxypolyurethane resin is facilitated by reacting at a temperature of 0 to 150 ° C., preferably 20 to 80 ° C. for 30 minutes to 3 hours in the presence or absence of an organic solvent and a catalyst. Can get to. However, it is necessary to pay attention to the fact that the reaction is carried out at a temperature lower than the dissociation temperature of the masking agent at the time of reaction, so that the polyhydroxy polyurethane resin after the reaction has a masked isocyanate group in its structure.

  As described above, the resin composition based on the self-crosslinking polyhydroxypolyurethane resin used in the present invention is used in the form of an organic solvent solution or an aqueous dispersion in the production of artificial leather. When the resin composition is used in the form of an organic solvent solution, the following organic solvent is preferably used. Examples thereof include dimethylformamide, dimethyl sulfoxide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone and the like. The resin concentration in 100% by mass of the organic solvent solution is preferably 10 to 60% by mass. If the resin concentration is less than 10% by mass, the film formability in wet film formation is inferior, and the thickness of the film is insufficient. On the other hand, if the resin concentration exceeds 60% by mass, the formation of the porous layer in the wet film formation may be incomplete and the organic solvent may remain in the film. Is also not preferable.

  When the resin composition mainly composed of the self-crosslinking polyhydroxypolyurethane resin used in the present invention is used in the form of an aqueous dispersion, it is preferably used as follows. That is, a carboxyl group is introduced into the resin by semi-esterifying or semi-amidating a hydroxyl group or NH group in the self-crosslinking polyhydroxy polyurethane resin with an acid anhydride. Thereafter, the carboxyl group is preferably neutralized with ammonia, an organic amine compound, an inorganic base or the like to form a carboxylate and used as a self-emulsifying aqueous dispersion. Examples of the acid anhydride used here include phthalic anhydride, trimellitic anhydride, hexahydrophthalic anhydride, and the like. Examples of the organic amine compound include monoethanolamine, diethanolamine, triethanolamine, diethylethanolamine, aminoethylethanolamine and the like. Further, the resin composition containing the self-crosslinking polyhydroxypolyurethane resin as a main component may be an aqueous dispersion emulsified in water by a surfactant according to a conventional method.

<Other ingredients>
In addition, the resin composition based on the self-crosslinking type polyhydroxypolyurethane resin used in the present invention is suitable for workability such as impregnation, coating and coating, and for adjusting the texture and performance of the obtained artificial leather. In addition to the resin, various conventionally known other resins can be mixed and used. Other resins used for mixing are preferably those in which the masked isocyanate groups in the self-crosslinking polyhydroxypolyurethane resin can chemically react with the isocyanate groups generated by dissociation by heating or the like. However, the present invention is not limited to this, and resins having no reactivity can also be used in the present invention.

  The resin used in combination with the self-crosslinking type polyhydroxypolyurethane resin is preferably a polyurethane resin conventionally used as a material for forming the artificial leather, but is not particularly limited. For example, acrylic resin, polyester resin, polybutadiene resin, silicone resin, melamine resin, phenol resin, phenoxy resin, vinyl chloride resin, vinyl chloride-vinyl acetate resin, cellulose resin, alkyd resin, modified cellulose resin, fluorine resin, polyvinyl Butyral resins, epoxy resins, polyamide resins and the like can also be used. Moreover, when using these resin together, the usage-amount is 5-90 mass parts with respect to 100 mass parts of polyhydroxy polyurethane resin of this invention. Of course, the more the proportion of the self-crosslinking polyhydroxypolyurethane resin of the present invention is used, the more the obtained artificial leather becomes a more environmentally friendly product.

  In addition, the resin composition mainly composed of the self-crosslinking type polyhydroxypolyurethane resin used in the present invention includes an antioxidant, an ultraviolet absorber, a hydrolysis inhibitor, a pigment, a dye, a flame retardant, You may mix | blend various additives, such as a filler.

<Pseudo leather>
The artificial leather of the present invention is characterized in that a resin composition mainly composed of a self-crosslinking polyhydroxypolyurethane resin having an isocyanate group masked in the structure described above is filled or laminated on a base fabric. And The method for producing the artificial leather of the present invention is not limited at all within the scope of the present invention, and known artificial leather and synthetic leather production methods can be used. Further, the artificial leather of the present invention is provided with a vinyl chloride resin layer containing a plasticizer on a base fabric, which is used as a base sheet, and the self-crosslinking polyhydroxy which characterizes the present invention on the base sheet. What formed the layer which consists of a resin composition which has a polyurethane resin as a main component is also contained.

  As the base fabric (base material sheet) constituting the artificial leather of the present invention, any base fabric (base material sheet) conventionally used for manufacturing artificial leather can be used and is not particularly limited.

  In the self-crosslinking polyhydroxypolyurethane resin characterizing the present invention used for forming the artificial leather of the present invention, the masking portion of the isocyanate group masked by heat treatment is dissociated to form an isocyanate group. And since the produced | generated isocyanate group and the hydroxyl group in polyhydroxy polyurethane resin react and self-crosslink and produce | generate a crosslinked resin, it interacts strongly at a base fabric (base material sheet) and an interface. As a result, excellent adhesion and flexibility of the resin to the base sheet, and excellent performance of imparting an antistatic effect to the formed resin layer can be obtained, and the performance of the artificial leather can be improved. . The formed artificial leather has excellent scratch resistance, abrasion resistance, chemical resistance, and heat resistance. The polyhydroxypolyurethane resin used in the synthesis of the self-crosslinking polyhydroxypolyurethane resin used in the present invention is synthesized using a five-membered cyclic carbonate compound. Since the cyclic carbonate compound is obtained by reacting an epoxy compound and carbon dioxide, carbon dioxide can be taken into the resin and fixed. This means that the present invention can provide artificial leather that is useful from the viewpoint of reducing greenhouse gases and that can be provided as an environmental protection product that cannot be achieved by conventional products.

  Next, the present invention will be described in more detail with reference to specific production examples, polymerization examples, examples and comparative examples, but the present invention is not limited to these examples. In the following examples, “part” and “%” are based on mass unless otherwise specified.

<Production Example 1> (Production of modifier)
Trimethylolpropane and hexamethylene diisocyanate trimer adduct (Coronate HL (trade name), Nippon Polyurethane NCO = 12.9%, solid content 75%) 100 parts, ethyl acetate 24.5 parts at 100 ° C. While stirring well, 25.5 parts of ε-caprolactam was added and allowed to react for 5 hours. According to the infrared absorption spectrum of the obtained modifier (Horiba FT-720), absorption due to free isocyanate groups remains at 2,270 cm ⁻¹ . When this free isocyanate group is quantified, the solid content is 50%. The measured value was 1.8% while the theoretical value was 2.1%.

The structure of the main compound of the modifier obtained above is estimated as the following formula.

<Production Example 2> (Production of modifier)
Add 100 parts of hexamethylene diisocyanate and water adduct (Duranate 24A-100 (trade name), manufactured by Asahi Kasei Co., Ltd., NCO = 23.0%), 32 parts of methyl ethyl ketoxime while stirring ethyl acetate at 80 ° C. The reaction was performed for 5 hours. According to the infrared absorption spectrum of the obtained modifier, absorption due to free isocyanate groups remains at 2,270 cm ⁻¹ , and when this free isocyanate group is determined, the theoretical value is 2.9% at a solid content of 50%. On the other hand, the measured value was 2.6%.

The structure of the main compound of the modifier obtained above is estimated as the following formula.

<Production Example 3> (Production of modifier)
Trimethylol propane and tolylene diisocyanate trimer adduct (Korone preparative L (trade name), manufactured by Nippon Polyurethane Industry Co., NCO = 12.5%, solid content 75%) 100 parts of ethyl acetate 67.3 parts, 80 17.3 parts of methyl ethyl ketoxime was added while stirring well at 0 ° C. and allowed to react for 5 hours. According to the infrared absorption spectrum of the resulting modifier, absorption due to free isocyanate groups remains at 2,270 cm ⁻¹ , and when the free isocyanate groups are quantified, the theoretical value is 2.3% at a solid content of 50%. On the other hand, the measured value was 2.0%.

The structure of the main compound of the modifier obtained above is estimated as the following formula.

<Production Example 4> (Production of 5-membered cyclic carbonate compound)
In a reaction vessel equipped with a stirrer, a thermometer, a gas inlet tube and a reflux condenser, a divalent epoxy compound represented by the following formula A (Epicoat 828 (trade name), manufactured by Japan Epoxy Resins Co., Ltd., epoxy equivalent 187 g) / Mol) 100 parts, 100 parts of N-methylpyrrolidone and 1.5 parts of sodium iodide were added and dissolved uniformly.

  Thereafter, the mixture was heated and stirred at 80 ° C. for 30 hours while bubbling carbon dioxide gas at a rate of 0.5 liter / min. After completion of the reaction, the obtained solution was gradually added to 300 parts of n-hexane with high-speed stirring at 300 rpm, and the resulting powdery product was filtered with a filter, further washed with methanol, and N-methylpyrrolidone and Sodium iodide was removed. The powder was dried in a drier to obtain 118 parts (yield 95%) of a white powder 5-membered cyclic carbonate compound (1-A).

In the infrared absorption spectrum of the obtained product, the peak derived from the epoxy group of the raw material in the vicinity of 910 cm ⁻¹ almost disappeared in the product, and the carbonyl group of the cyclic carbonate group not present in the raw material in the vicinity of 1,800 cm ^−1. Absorption was confirmed. Moreover, the number average molecular weight of the product was 414 (polystyrene conversion, Tosoh; GPC-8220). In the obtained 5-membered cyclic carbonate compound (1-A), 19% of carbon dioxide was immobilized.

<Production Example 5> (Production of 5-membered cyclic carbonate compound)
In place of the divalent epoxy compound A used in Production Example 4, the reaction was carried out in the same manner as in Production Example 4 using the following formula B (EX-212 (trade name), manufactured by Nagase ChemteX Corporation, epoxy equivalent 151 g / mol). Thus, 111 parts (yield 86%) of a colorless and transparent liquid 5-membered cyclic carbonate compound (1-B) was obtained.

生成物は製造例４の場合と同様に、赤外吸収スペクトル、ＧＰＣ、ＮＭＲで確認した。得られた５員環環状カーボネート基化合物（１−Ｂ）中には、２２．５％の二酸化炭素が固定化されている。

The product was confirmed by infrared absorption spectrum, GPC and NMR as in Production Example 4. In the obtained 5-membered cyclic carbonate group compound (1-B), 22.5% of carbon dioxide is immobilized.

<Polymerization Example 1> (Production of self-crosslinking type polyhydroxy polyurethane resin)
A reaction vessel equipped with a stirrer, a thermometer, a gas introduction tube and a reflux condenser was replaced with nitrogen, and 100 parts of the 5-membered cyclic carbonate compound obtained in Production Example 4 was added thereto so that the solid content was 35%. N-methylpyrrolidone was added and dissolved uniformly. Next, 27.1 parts of hexamethylenediamine was added and stirred for 10 hours at a temperature of 90 ° C., and the reaction was continued until no hexamethylenediamine could be confirmed. Next, 20 parts of the modifier of Production Example 1 (solid content 50%) was added and reacted at 90 ° C. for 3 hours. After confirming that the absorption of the isocyanate group by the infrared absorption spectrum disappeared, a self-crosslinking polyhydroxy polyurethane resin solution was obtained.

<Polymerization Examples 2 to 4> (Production of self-crosslinking type polyhydroxy polyurethane resin)
Thereafter, in the same manner as in Polymerization Example 1, a 5-membered cyclic carbonate compound, a polyamine compound and a modifier are combined and reacted in the same manner as in Polymerization Example 1, and the self-crosslinking type of Polymerization Examples 2 to 4 shown in Table 1 A polyhydroxy polyurethane resin solution was obtained.

<Comparative polymerization example 1> (Production of polyhydroxypolyurethane resin)
A polyhydroxy polyurethane resin solution was used in the same manner except that the modifier of Production Example 1 used in Polymerization Example 1 was not used.

<Comparative Polymerization Example 2> (Polyester urethane resin)
The polyester polyurethane resin used in the comparative example was synthesized as follows. A reaction vessel equipped with a stirrer, a thermometer, a gas introduction pipe and a reflux condenser was replaced with nitrogen, and 150 parts of polybutylene adipate having an average molecular weight of about 2,000 and 15 parts of 1,4-butanediol were added to 250 parts. Dissolved in dimethylformamide. Thereafter, 62 parts of water-added MDI (methylenebis (1,4-cyclohexane) -diisocyanate) dissolved in 171 parts of dimethylformamide was gradually added dropwise while stirring well at 60 ° C. The reaction was performed for 6 hours.
This solution had a viscosity of 3.2 MPa · s (25 ° C.) at a solid content of 35%. The film obtained from this solution had a breaking strength of 45 MPa, a breaking elongation of 480%, and a heat softening temperature of 110 ° C.

<Comparative Polymerization Example 3> (Polycarbonate polyurethane resin)
The polycarbonate polyurethane resin used in the comparative example was synthesized as follows. In the same manner as in Comparative Polymerization Example 2, 150 parts of polycarbonate diol having an average molecular weight of about 2,000 (manufactured by Ube Industries) and 15 parts of 1,4-butanediol were dissolved in 250 parts of dimethylformamide. Thereafter, 62 parts of water-added MDI dissolved in 171 parts of dimethylformamide was gradually added dropwise with stirring at 60 ° C., and reacted at 80 ° C. for 6 hours after the completion of the addition. This solution had a solid content of 35% and a viscosity of 1.6 MPa · s (25 ° C.). The film obtained from this solution had a breaking strength of 21 MPa, a breaking elongation of 250%, and a thermal softening temperature of 135 ° C.

<Examples 1-6, Comparative Examples 1-4>
Using the resins of Polymerization Examples 1 to 4 and Comparative Polymerization Examples 1 to 3, respectively, skin paints were prepared according to the formulations shown in Tables 2 and 3, and evaluated by the following methods.

(Artificial leather)
The resins of the polymerization example and the comparative polymerization example were applied onto a nonwoven fabric made of polystyrene-polyester fibers so as to have a thickness of 1 mm, and immersed in a 10% aqueous solution of DMF at 25 ° C. to be solidified. After washing, it was dried by heating (150 ° C./10 minutes) to obtain an artificial leather having a porous layer sheet.

(Synthetic leather)
A polyurethane-based resin solution (Rezamin UD-602S (trade name), manufactured by Dainichi Seika Kogyo Co., Ltd.) as an adhesive layer on the woven fabric is applied and dried by heating to a thickness of 10 μm. A base sheet for artificial leather was prepared. On the other hand, the resin solutions obtained in Polymerization Examples 1 to 4 and Comparative Polymerization Examples 1 to 3 were each applied onto release paper and heated and dried (150 ° C./10 minutes) to form a film having a thickness of about 15 μm. This was bonded to the base sheet obtained above to obtain a synthetic leather.

[Evaluation]
Each artificial leather obtained above and each artificial leather of each synthetic leather was evaluated by the following methods and criteria.
(Texture)
Each artificial leather was judged by the hand feeling. The results are shown in Tables 2 and 3.
○: Soft △; Slightly hard ×; Hard

(chemical resistance)
Toluene was dropped on the surface of each synthetic leather obtained above, and a solvent was added dropwise to maintain a wet state at all times, followed by wiping after 1 hour. The results are shown in Table 3.
○: No dripping marks are observed on the coated surface. Δ: Slight changes such as dripping marks and swelling are observed but not noticeable. X: Changes in surface condition (swelling, etc.) are clearly recognized.

(Surface wear resistance)
About each synthetic leather obtained above, the frequency | count until a scratch generate | occur | produces was measured for the No. 6 canvas with the load of 1 kgf using the plane abrasion tester. The results are shown in Table 3.
○: 5000 times or more Δ: 2000 times or more to less than 5000 times ×; less than 2000 times

(Thermal softening point)
When the above synthetic leather was prepared, a film obtained by coating on a release paper and heating and drying (150 ° C./10 minutes) was measured according to JIS K7206 (Vicat softening point measurement method). The results are shown in Table 3.

(Environmental compatibility)
Each artificial leather was evaluated as ◯ × depending on whether carbon dioxide was immobilized in the resin used. The results are shown in Tables 2 and 3.

The artificial leather of the present invention uses a resin composition containing a self-crosslinking polyhydroxypolyurethane resin as a main component, thereby masking isocyanate groups that are dissociated by heat in the structure, and the polyhydroxypolyurethane in the resin. Since the hydroxyl group of the resin reacts to become a cross-linked resin, a pseudo-leather excellent in scratch resistance, abrasion resistance, chemical resistance and heat resistance can be obtained.
In addition, the polyhydroxypolyurethane resin, which is the main component of the resin composition used in the present invention, is a useful material that contributes to solving problems such as global warming and resource depletion by incorporating carbon dioxide into the resin and fixing it. Therefore, the artificial leather obtained by using this can also provide environmentally friendly products that could not be achieved with conventional products.

Claims (4)

  Filling the base fabric with a resin composition based on a self-crosslinking polyhydroxy polyurethane resin having an isocyanate group masked in its structure, derived from the reaction between a 5-membered cyclic carbonate compound and an amine compound, or Pseudo leather characterized by being laminated. The 5-membered cyclic carbonate compound, a reaction product of an epoxy compound and carbon dioxide, and the self-crosslinking polyhydroxy polyurethane resin, in the structure of their derived from carbon dioxide used in the reaction The artificial leather according to claim 1, wherein carbon dioxide is incorporated in an amount of 1 to 25% by mass.   The masked isocyanate group is a reaction product of an organic polyisocyanate group and a masking agent, and the masked portion is dissociated by heat treatment to form an isocyanate group. The artificial leather according to claim 1 or 2, which reacts with a hydroxyl group in the structure to self-crosslink.   The artificial leather according to any one of claims 1 to 3, wherein the resin composition further contains another resin.