JP2013170320A - Imitation leather - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide imitation leather which is comparable to conventional imitation leather and excellent in flexibility, slidability, scratch resistance, abrasion resistance, chemical resistance and heat resistance, and can contribute to a reduction in carbon dioxide, which is cited worldwide as a global warming gas, by producing the imitation leather using a material that incorporates carbon dioxide into a resin and immobilizes the carbon dioxide therein, and is also useful as an environmentally friendly product from the viewpoint of global environment preservation.SOLUTION: There is provided imitation leather obtained by filling or laminating a resin composition comprising essentially a self-cross-linking polysiloxane-modified polyhydroxy polyurethane resin which is derived from a reaction of a 5-membered cyclic carbonate compound with an amine-modified polysiloxane compound and has a masked isocyanate group in its structure, into or on a base fabric.

Description

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

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

  Artificial leather has a structure most similar to natural leather among artificial leather, and a nonwoven fabric is usually used as a base fabric. As a general manufacturing method of artificial leather, for example, 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). Then, using this as a base material, the surface of the surface is further coated or laminated with a polyurethane resin to provide a smooth surface, and the surface is ground and brushed to create a suede tone. is there.

  On the other hand, in synthetic leather, fabrics such as woven fabric and brushed fabric are used as the base fabric, but generally, they are roughly classified into dry synthetic leather and wet synthetic leather due to the difference in the production method. The dry synthetic leather can be produced by applying a polyurethane resin directly to the base fabric and drying, or by applying a polyurethane resin on the release paper, then drying and filming it, and bonding it to the base fabric with an adhesive. There is a way. In contrast, wet synthetic leather forms a porous layer by impregnating or applying a DMF solution of polyurethane resin similar to that used in the production of artificial leather to a base fabric and then coagulating and drying in water. Can be obtained. Further, in both cases, the dry synthetic leather and the wet synthetic leather obtained as described above are coated with a polyurethane resin on each surface or provided with a laminate layer made of the resin to make it smooth. There is a case. In some cases, the surface is ground and raised to be suede.

  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 global issue. It has become a challenge. 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 requires the use of an organic solvent, by using a polyurethane resin that can be dispersed or emulsified in an aqueous medium, it is possible to reduce VOC (volatile organic compound) emissions as much as possible, From the viewpoint of carbon neutrality, the use of plant-derived materials as manufacturing materials has been actively studied. However, each of them has a difference in performance compared to the conventional products, and it can be said that there is a problem in practical use, and it is still insufficient from the viewpoint of realizing the 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 these circumstances, the artificial leather products are comparable in performance to the conventional products, and have superior surface scratch resistance, abrasion resistance, chemical resistance, heat resistance, and global scale. There is a demand for the development of environmentally friendly products with environmental conservation.

  Therefore, the object of the present invention is not particularly inferior to conventional artificial leather, and is excellent in texture, surface scratch resistance, abrasion resistance, chemical resistance, and heat resistance, and is fixed by incorporating carbon dioxide into the resin. 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 following invention. That is, the present invention is mainly composed of a self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin having an isocyanate group masked in its structure, which is derived from the reaction between a 5-membered cyclic carbonate compound and an amine-modified polysiloxane compound. The artificial leather characterized by filling or laminating a resin composition with a base fabric.

The following are mentioned as a preferable form of this invention.
The 5-membered cyclic carbonate compound is a reaction product of an epoxy compound and carbon dioxide, and carbon dioxide is contained in the range of 1 to 25% by mass in the structure of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin. The above-mentioned artificial leather comprising. The artificial leather in which the content of the polysiloxane segment in the molecule of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin is 1 to 75% 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, and a self-crosslinking polysiloxane modified polyhydroxy The artificial leather as described above, which reacts with a hydroxyl group in the structure of the polyurethane resin to self-crosslink. The artificial leather as described above, wherein the resin composition further contains another resin.

  According to the present invention, it is excellent in texture, surface scratch resistance, abrasion resistance, chemical resistance, and heat resistance, and is similar to conventional artificial leather, and imitates a material in which carbon dioxide is taken in and fixed in a resin. 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. Provided with fake leather.

Next, the present invention will be described in more detail with reference to preferred embodiments.
The artificial leather of the present invention has an isocyanate group masked in its structure derived from a reaction between a 5-membered cyclic carbonate compound and an amine-modified polysiloxane compound in a resin composition to be filled or laminated on a base fabric. A resin composition comprising as a main component a unique self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin is used. In the resin characterizing the present invention, since the masked isocyanate group in the structure is a reaction product of an organic polyisocyanate group and a masking agent, the masked portion is dissociated by heat treatment to remove the isocyanate group. It forms and reacts with the hydroxyl group in the structure of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin to self-crosslink. For this reason, by using this resin, artificial leather excellent in texture, surface scratch resistance, abrasion resistance, chemical resistance, and heat resistance can be obtained. Further, among the above-mentioned resins characterizing the present invention, particularly preferable from the viewpoint of global environmental conservation, the five-membered cyclic carbonate compound is a reaction product of an epoxy compound and carbon dioxide, and the structure of the resin It contains carbon dioxide in the range of 1 to 25% by mass.

[Self-crosslinking polysiloxane modified polyhydroxy polyurethane resin]
The self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin used in the present invention uses, for example, a modifier having at least one free isocyanate group and a masked isocyanate group. It can be easily obtained by reacting with a hydroxyl group in a polysiloxane-modified polyhydroxypolyurethane resin derived from a reaction between a 5-membered cyclic carbonate compound and an amine-modified polysiloxane 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.

(Modifier)
<Organic polyisocyanate compound>
The components of the modifier used in the production of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin used in the present invention will be described. As the modifier, as described above, a reaction product of an organic polyisocyanate compound and a masking agent is used. The organic polyisocyanate compound is an organic 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 Diisocyanate, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate, tolidine diisocyanate, xylylene diisocyanate, and adducts of these organic polyisocyanate compounds with other compounds such as Examples include, but are not limited to, structural formulas.

<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, pyridine-based compounds, etc. 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 phenols 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>
Synthesis of a modifier having at least one free isocyanate group and a masked isocyanate group used in the present invention by reacting the organic polyisocyanate compound listed above with the masking agent listed above. Can do. The synthesis method is not particularly limited. For example, the masking agent as described above and an organic polyisocyanate compound are used in a functional group ratio in which one or more isocyanate groups are excessive in one molecule, in the presence or absence of an organic solvent and a catalyst. In the presence, 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.

(Polysiloxane-modified polyhydroxypolyurethane resin)
The polysiloxane-modified polyhydroxypolyurethane resin modified with the specific modifier as described above of the present invention is obtained by reaction of a 5-membered cyclic carbonate compound and an amine-modified polysiloxane 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 particularly, 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. at normal pressure or slightly elevated pressure for 10-20 hours. It is obtained by reacting with.

  Examples of the epoxy compound used in the present invention 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 compounds exemplified above, 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 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, acetic acid Examples thereof include metal acetates such as copper 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 between 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.

  The polysiloxane-modified polyhydroxypolyurethane resin used in the present invention comprises, for example, a five-membered cyclic carbonate compound obtained by the above reaction and an amine-modified polysiloxane compound, as shown by the following [Formula-B]. It can obtain by making it react at the temperature of 20 to 150 degreeC in presence of a solvent.

  Examples of the amine-modified polysiloxane compound used in the present invention include the following compounds.

  The amine-modified polysiloxane 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 compounds exemplified above, 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.

  The polysiloxane-modified polyhydroxypolyurethane resin that can be obtained as described above is an amount in which the content of the polysiloxane segment in the resin molecule is 1 to 75% by mass based on the content of siloxane in the resin molecule. It is preferable that If it is less than 1% by mass, the expression of the function accompanying the surface energy based on the polysiloxane segment becomes insufficient, which is not preferable. On the other hand, if it exceeds 75% by mass, the performance of the polyhydroxypolyurethane resin such as mechanical strength and abrasion resistance becomes insufficient, such being undesirable. Preferably it is 2-70 mass%, More preferably, it is 5-60 mass%.

  The polysiloxane-modified polyhydroxypolyurethane resin of the present invention preferably has a number average molecular weight (measured by GPC, standard polystyrene equivalent value; the same applies hereinafter) of about 2,000 to 100,000. Is about 5,000 to 70,000.

  The hydroxyl value of the polysiloxane-modified polyhydroxypolyurethane resin used in the present invention is preferably 20 to 300 mgKOH / g. If the hydroxyl value is less than the above range, it is difficult to obtain a carbon dioxide reduction effect. On the other hand, if the hydroxyl value exceeds the above range, various physical properties as a polymer compound may not be obtained.

(Self-crosslinking polysiloxane modified polyhydroxy polyurethane resin)
The self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin used in the present invention is obtained by reacting the modifier obtained as described above with a polysiloxane-modified polyhydroxypolyurethane resin. Specifically, it can be obtained by reacting the hydroxyl group in the polysiloxane-modified polyhydroxypolyurethane resin with at least one free isocyanate group in the modifier.

The modification rate of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin used in the present invention with a modifier is preferably 2 to 60%. If the modification rate is less than 2%, sufficient cross-linking will not occur, and when used in the production of artificial leather, the heat resistance and chemical resistance of the product may be insufficient. On the other hand, if the modification rate exceeds 60%, 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 polysiloxane-modified polyhydroxypolyurethane resin is performed in the presence or absence of an organic solvent and a catalyst, for example, at a temperature of 0 to 150 ° C., preferably 20 to 80 ° C., for 30 minutes to 3 hours. Then, the self-crosslinking polysiloxane-modified polyhydroxy polyurethane resin used in the present invention can be easily obtained. However, attention should be paid to the fact that the reaction is carried out at a temperature lower than the dissociation temperature of the masking agent during the reaction, and the resin after the reaction needs to have a masked isocyanate group in its structure.

  As described above, the resin composition based on the self-crosslinking polysiloxane-modified 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. It is preferable to do. 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. When 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, which may cause insufficient strength of the resulting artificial leather. On the other hand, if the resin concentration exceeds 60% by mass, the formation of the porous layer in the wet film formation is incomplete, and problems such as the organic solvent remaining in the film may occur, which is not preferable. Also, from the viewpoint of measures against VOC, it is not preferable to use an excessive organic solvent.

  In the present invention, when the resin composition mainly composed of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin is used in the form of an aqueous dispersion, the following configuration is preferable. First, a hydroxyl group or NH group in a self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin is half-esterified or half-amidated with an acid anhydride to introduce a carboxyl group into the resin. 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 polysiloxane-modified polyhydroxypolyurethane resin as a main component may be an aqueous dispersion emulsified in water by a surfactant according to a conventional method.

(Other ingredients)
Further, the resin composition mainly composed of the self-crosslinking type polysiloxane modified polyhydroxypolyurethane resin used in the present invention is suitable for work such as impregnation, coating and coating performed on the base fabric, and the texture of the obtained artificial leather. In order to adjust various performances, various conventionally known resins can be mixed and used. Other resins used for mixing are preferably those capable of chemically reacting with isocyanate groups generated by dissociation of the masking agent in the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin, but not reactive. However, it can be used in the present invention.

  The resin used in combination is preferably a polyurethane resin conventionally used for 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, fluororesin, polyvinyl butyral resin An epoxy resin, a polyamide resin, or the like can be used. Moreover, when using these resin together, the usage-amount is 5-90 mass% with respect to the self-crosslinking type polysiloxane modified polyhydroxy polyurethane resin which is essential in the present invention. As the proportion of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin of the present invention increases, the obtained artificial leather becomes a more preferable environmentally friendly product.

  In addition to the above-mentioned various resins, the composition mainly composed of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin used in the present invention includes antioxidants, ultraviolet absorbers, hydrolysis inhibitors, pigments, dyes, You may mix | blend various additives, such as a flame retardant and a filler, as needed.

〔imitation leather〕
The artificial leather of the present invention is mainly composed of a self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin having an isocyanate group masked in the structure described above in a resin composition filled or laminated on a base fabric. It is characterized by using. Therefore, the manufacturing method of artificial leather is not limited at all, and any known manufacturing method of artificial leather and synthetic leather 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 polysiloxane characterizing the present invention on the base sheet. What formed the layer which consists of a resin composition which has a modified polyhydroxy polyurethane resin as a main component is also contained.

  As the base fabric constituting the artificial leather of the present invention, any base fabric conventionally used for manufacturing artificial leather including the above-described base sheet can be used and is not particularly limited.

  The artificial leather of the present invention having the above structure is excellent in texture and has excellent surface scratch resistance, abrasion resistance, chemical resistance, and heat resistance as a result of using the above-described specific polyurethane resin as the resin. It becomes. In addition to this, the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin characterizing the present invention is synthesized using a 5-membered cyclic carbonate compound. As described above, the 5-membered cyclic carbonate compound is synthesized. Since it is obtained by reacting an epoxy compound and carbon dioxide, carbon dioxide can be incorporated into the resin and immobilized. This means that the present invention makes it possible to provide artificial leather as an environmental protection product that could not be achieved with conventional products, which is also useful from the viewpoint of reducing greenhouse gases.

  Next, the present invention will be described in more detail with reference to specific production 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), manufactured by Nippon Polyurethane, NCO = 12.9%, solid content 75%] 100 parts, ethyl acetate 24.5 parts, While stirring well at 100 ° C., 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 (measured with FT-720 manufactured by Horiba, the same applies hereinafter), absorption due to free isocyanate groups remained at 2,270 cm ⁻¹ . When this free isocyanate group was quantified, the theoretical value was 2.1% at a solid content of 50%, whereas the measured value was 1.8%. Therefore, the main structure of the above modifier is presumed to be the following formula.

<Production Example 2> (Production of modifier)
Hexamethylene diisocyanate and water adduct [Duranate 24A-100 (trade name), Asahi Kasei Co., Ltd., NCO = 23.0%] 100 parts, while stirring ethyl acetate at 80 ° C, 32 parts of methyl ethyl ketoxime was added. The reaction was performed 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 this free isocyanate group is quantified, the theoretical value is 2. at a solid content of 50%. The actual measured value was 2.6%, compared with 9%. Therefore, the main structure of the above modifier is estimated as the following formula.

<Production Example 3> (Production of 5-membered cyclic carbonate compound)
In a reaction vessel equipped with a stirrer, a thermometer, a gas introduction pipe 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.

  Then, carbon dioxide gas was heated and stirred at 80 ° C. for 30 hours while bubbling 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 obtained powder was dried in a drier to obtain 118 parts (yield 95%) of a white powder 5-membered cyclic carbonate compound (1-A).

The infrared absorption spectrum of the product obtained above shows that the peak derived from the epoxy group near 910 cm ⁻¹ almost disappears in the product, and the carbonyl group of the cyclic carbonate group that does not exist in the raw material near 1,800 cm ^−1. Absorption was confirmed. The number average molecular weight of the product was 414 (polystyrene conversion value, measured with GPC-8220 manufactured by Tosoh Corporation). In the obtained 5-membered cyclic carbonate compound (1-A), 19% of carbon dioxide was immobilized.

<Production Example 4> (Production of 5-membered cyclic carbonate compound)
Instead of the divalent epoxy compound A used in Production Example 3, the following formula B (manufactured by Toto Kasei Co., Ltd., YDF-170; epoxy equivalent 172 g / mol) was used and reacted in the same manner as in Production Example 3 to obtain a white powder. 121 parts (yield 96%) of 5-membered cyclic carbonate compound (1-B) was obtained. The obtained product was confirmed by infrared absorption spectrum, GPC, and NMR as in the case of Production Example 3. In the obtained 5-membered cyclic carbonate compound (1-B), 20.3% of carbon dioxide was immobilized.

<Polymerization Example 1> (Production of self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin)
A reaction vessel equipped with a stirrer, a thermometer, a gas introduction pipe and a reflux condenser was replaced with nitrogen, and 100 parts of the 5-membered cyclic carbonate compound obtained in Production Example 3 was added thereto so that the solid content became 35%. N-methylpyrrolidone was added to and uniformly dissolved. Next, 201 parts of an amine-modified polysiloxane compound having a structure represented by the following formula C is added to obtain a predetermined equivalent, stirred at a temperature of 90 ° C. for 10 hours, and allowed to react until no amine-modified polysiloxane compound can be confirmed. A polysiloxane-modified polyhydroxypolyurethane resin was synthesized. Next, the modifying agent of Production Example 1 (solid content 50%) was added in an amount such that the solid content ratio with the resin synthesized above was 100: 10, and reacted at 90 ° C. for 3 hours. After confirming that the absorption of the isocyanate group by the infrared absorption spectrum disappeared, the self-crosslinked polysiloxane-modified polyhydroxypolyurethane resin solution of the present invention was obtained.

<Polymerization Examples 2 to 4> (Production of self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin)
Thereafter, in the same manner as in Polymerization Example 1, a 5-membered cyclic carbonate compound, an amine-modified polysiloxane compound, and the modifier obtained in Production Example 1 or 2 were combined and reacted in the same manner as in Polymerization Example 1, and Table 1 The self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin solutions of Polymerization Examples 2 to 4 described in 1 were obtained.

<Comparative polymerization example 1> (Production of polyhydroxypolyurethane resin)
The polyhydroxy 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 100 parts of the 5-membered cyclic carbonate compound obtained in Production Example 4 was added to this so that the solid content was 35%. N-methylpyrrolidone was added and dissolved uniformly. Next, a predetermined equivalent of an amine-modified polysiloxane compound was added and stirred for 10 hours at a temperature of 90 ° C. until the amine-modified polysiloxane compound could not be confirmed. Properties of the obtained polysiloxane-modified polyhydroxypolyurethane resin are as shown in Table 1.

<Comparative polymerization example 2> (Production of polyester polyurethane 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 tube 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 200 parts. In a mixed organic solvent consisting of 50 parts of dimethylformamide. Thereafter, 62 parts of water-added MDI [4,4′-methylenebis (cyclohexyl isocyanate)] dissolved in 171 parts of dimethylformamide was gradually added dropwise while stirring well at 60 ° C. The reaction was carried out at 6 ° C. 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> (Production of polysiloxane-modified polyurethane resin)
The polysiloxane modified polyurethane resin used in the comparative example was synthesized as follows. To 150 parts of polydimethylsiloxane diol represented by the following formula D and having an average molecular weight of about 3,200 and 10 parts of 1,4-butanediol, 250 parts of dimethylformamide solvent are added, and 40 parts of water is added thereto. A solution prepared by dissolving added MDI in 120 parts of dimethylformamide was gradually added dropwise. After completion of the addition, the mixture was reacted at 80 ° C. for 6 hours. This solution has a solid content of 35% and a viscosity of 1.6 MPa · s (25 ° C.). A film obtained from this solution has a breaking strength of 21 MPa and a breaking elongation of 250%, and the thermal softening temperature is It was 135 ° C.

<Examples 1-8, Comparative Examples 1-6>
[Manufacture of artificial leather]
The resin solutions of Polymerization Examples 1 to 4 and Comparative Polymerization Examples 1 to 3 were used, respectively, to prepare artificial leather paints according to the formulations shown in Tables 2 and 3. Using the obtained paints, artificial leather and synthetic leather were produced as follows, and the obtained artificial leathers were evaluated by the following methods.

(Artificial leather)
Using the artificial leather paint containing each of the resins of the polymerization example and the comparative polymerization example, it was applied on a non-woven fabric made of polystyrene-polyester fiber so as to have a thickness of 1 mm, and in a DMF 10% aqueous solution at 25 ° C. It was immersed and solidified. After washing, heat drying was performed at 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.] is applied and dried as an adhesive layer on the woven fabric so that the thickness when dried is 10 μm. A base fabric sheet for artificial leather was prepared. On the other hand, each of the artificial leather paints containing the resin solutions obtained in Polymerization Examples 1 to 4 and Comparative Polymerization Examples 1 to 3 was applied onto a release paper, and then heat-dried at 150 ° C./10 minutes to obtain a thickness of about 15 μm. A film was formed. The obtained film was bonded to the above artificial leather base fabric sheet to obtain synthetic leather.

[Evaluation]
Each artificial leather and synthetic leather obtained as described above was used for evaluation according to the following methods and standards. The results are summarized in Tables 2 and 3.
(Texture)
About each artificial leather, it judged by the touch of the hand and evaluated by the following reference | standard.
○: Soft △; Slightly hard ×; Hard

(Coefficient of friction)
The friction coefficient of the surface of each artificial leather obtained above was measured with a surface property tester (manufactured by Shinto Kagaku) and evaluated by the measured value.

(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 dripped part wiped off was visually observed and evaluated according to the following criteria.
○: No dripping traces are observed on the coated surface. Δ: Slight dropping traces are observed but not noticeable.

(Surface wear resistance)
About each synthetic leather obtained above, the frequency | count until a scratch | wound generate | occur | produces was measured for the No. 6 canvas with the load 1Kgf using the plane abrasion tester.
○: 5,000 times or more Δ; 2,000 times or more and less than 5,000 times ×; less than 2,000 times

(Thermal softening point)
About each synthetic leather obtained above, the thermal softening point was measured according to JIS K7206 (Vicat softening point measuring method), respectively.

(Environmental compatibility)
About each artificial leather, it judged by (circle) * by the presence or absence of the fixation of the carbon dioxide in the used resin.

The artificial leather of the present invention is characterized by using a resin composition mainly composed of a self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin as a forming material, but is masked by being dissociated by heat in the structure. Since the isocyanate group reacts with the hydroxyl group of the polysiloxane-modified polyhydroxypolyurethane resin in the resin to form a crosslinked resin, it has excellent scratch resistance, abrasion resistance, chemical resistance, and heat resistance. Due to the effect of the segment, it has excellent performance with both flexibility and slipperiness.
In addition, the polysiloxane-modified polyhydroxypolyurethane resin, which is the main component of the resin composition used in the present invention, is useful for solving problems such as global warming and resource depletion by incorporating carbon dioxide into the resin and fixing it. Since it is a material, the artificial leather obtained by using it can also provide products for environmental protection that cannot be achieved with conventional products.

Claims (5)

  A resin composition comprising, as a main component, a self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin having an isocyanate group masked in its structure, derived from a reaction between a 5-membered cyclic carbonate compound and an amine-modified polysiloxane compound. An artificial leather that is filled or laminated on a base fabric.   The 5-membered cyclic carbonate compound is a reaction product of an epoxy compound and carbon dioxide, and carbon dioxide is contained in the range of 1 to 25% by mass in the structure of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin. The artificial leather according to claim 1, comprising:   The artificial leather according to claim 1 or 2, wherein the content of the polysiloxane segment in the molecule of the self-crosslinking polysiloxane-modified polyhydroxypolyurethane resin is 1 to 75 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, and a self-crosslinking polysiloxane modified polyhydroxy The artificial leather according to any one of claims 1 to 3, which reacts with a hydroxyl group in the structure of the polyurethane resin to self-crosslink.   The artificial leather according to any one of claims 1 to 4, wherein the resin composition further contains another resin.