JP5596435B2 - Self-crosslinking polyhydroxypolyurethane resin and process for producing the same - Google Patents

Description

  The present invention relates to a novel self-crosslinking polyhydroxypolyurethane resin and a method for producing the same. More specifically, when used in forming materials such as films and molding materials, various coating materials, various paints, various binders, etc., it can be a product with excellent wear resistance, chemical resistance, and heat resistance, and it can be used as a manufacturing raw material. Since carbon dioxide is used and carbon dioxide can be fixed in the resin, the present invention relates to a self-crosslinking polyhydroxy polyurethane resin useful from the viewpoint of preventing global environmental destruction and a method for producing the same.

  Polyhydroxy polyurethane resins using carbon dioxide as a production raw material have been known for a long time (see, for example, Patent Documents 1 and 2), but the actual situation is that their application development has not progressed. This is because the polyhydroxypolyurethane resin is clearly inferior in characteristics as compared with the polyurethane-based resin compared with the same type of polymer compound.

  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 (for example, Non-Patent Documents 1 and 2).

  Under the background as described above, the present inventors have recognized that it is very useful to review the polyhydroxypolyurethane resin described above and to provide a technology that enables application development of the resin. It was. In other words, carbon dioxide, which is a raw material for polyhydroxypolyurethane resin, is an easily available and sustainable carbon resource. However, in recent years, the provision of technology for effectively using plastics fixed with carbon dioxide as a raw material has been provided. This is because it can be an effective means to solve important issues such as global warming and resource depletion facing the earth.

U.S. Pat. No. 3,072,613 JP 2000-319504 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

  However, in order to make the above-mentioned polyhydroxy polyurethane resin usable for industrial use, for example, it is possible to use it in the same manner as the same kind of petrochemical plastics, and of course, the performance is improved, and a new added value is added. There is a need. In other words, in addition to the viewpoint of protecting the global environment, there is a demand for the development of resins with improved performance essential for industrial materials, such as further heat resistance, chemical resistance, and wear resistance.

  Accordingly, an object of the present invention is a material that can be effectively used as an industrial product for a polyhydroxy polyurethane resin that is considered to contribute to solving problems such as global warming and resource depletion, but whose application has not been developed yet. It is to provide the technology. More specifically, the product formed from the resin is a self-crosslinking polyhydroxy which is satisfactory in terms of performance such as heat resistance, chemical resistance, and abrasion resistance, while being an environmentally friendly product. An object is to provide a polyurethane resin.

The above object is achieved by the present invention described below. That is, the present invention is characterized by having an isocyanate group masked in the structure derived from the reaction of a 5-membered cyclic carbonate compound and a diamine that is an amine compound (except for aminourethane) . A self-crosslinking polyhydroxypolyurethane resin is provided. The following are mentioned as a more preferable form. The self-crosslinking polyhydroxypolyurethane described above, wherein the 5-membered cyclic carbonate compound is a reaction product of an epoxy compound and carbon dioxide, and the structure contains carbon dioxide in an amount of 1 to 25% by mass. resin. The masked isocyanate group uses a modifier having at least one free isocyanate group and a masked isocyanate group, and the free isocyanate group of the modifier is converted into the 5-membered cyclic carbonate compound and the amine. By reacting with the hydroxyl group in the polyhydroxy polyurethane resin derived from the reaction with the compound, it has in its structure, and the masked part is dissociated by heat treatment to produce an isocyanate group, The self-crosslinking polyhydroxypolyurethane resin described above, which reacts with a hydroxyl group in the structure to self-crosslink.

Another embodiment of the present invention is a method for producing the self-crosslinking polyhydroxypolyurethane resin, wherein a modifier having at least one free isocyanate group and a masked isocyanate group is used. The free isocyanate group of the modifier is reacted with the hydroxyl group in the polyhydroxypolyurethane resin derived from the reaction between the 5-membered cyclic carbonate compound and the amine compound , diamine, and the isocyanate group masked in the structure is formed. A method for producing a self-crosslinking polyhydroxypolyurethane resin is provided.

  The following are mentioned as a more preferable form. The 5-membered cyclic carbonate compound is a reaction product of an epoxy compound and carbon dioxide, and 1 to 25% by mass of carbon dioxide in a polyhydroxy polyurethane resin derived from the reaction of the compound and an amine compound. The manufacturing method of said self-crosslinking type | mold polyhydroxy polyurethane resin included in the range of this. The method for producing a self-crosslinking polyhydroxypolyurethane resin, wherein the modifier is a reaction product of an organic polyisocyanate compound and a masking agent.

  As another embodiment of the present invention, there is provided a resin material obtained by mixing the above self-crosslinking polyhydroxypolyurethane resin with another binder resin.

  According to the present invention, a polyhydroxypolyurethane resin, which is a useful material considered to contribute to solving problems such as global warming and resource depletion, but whose application development has not progressed, can be a material that can be effectively used for industrial use. A self-crosslinking polyhydroxy polyurethane resin is provided. More specifically, according to the present invention, the formed product incorporates carbon dioxide and is an environmentally friendly product that can contribute to the reduction of greenhouse gases, but also has heat resistance, chemical resistance, wear resistance, etc. A self-crosslinked polyhydroxypolyurethane resin that is sufficiently satisfactory in terms of performance is provided.

  Next, the present invention will be described in more detail with reference to preferred embodiments. The self-crosslinking type polyhydroxy polyurethane resin of the present invention is characterized by having a masked isocyanate group in the structure derived from the reaction of a 5-membered cyclic carbonate compound and an amine compound. The self-crosslinking type polyhydroxy polyurethane resin uses a modifier having at least one free isocyanate group and a masked isocyanate group, and the free isocyanate group of the modifier is converted into a 5-membered cyclic carbonate compound and an amine. It can be obtained by reacting with a hydroxyl group in a polyhydroxy polyurethane resin derived from a reaction with a compound. Below, each component is demonstrated.

(Modifier)
<Organic polyisocyanate compound>
The components of the modifier used in the method for producing the self-crosslinking polyhydroxy polyurethane resin of the present invention will be described. As the modifier, a reaction product of an organic polyisocyanate compound and a masking agent is used. The organic polyisocyanate compound used in the present invention is an organic compound having at least two isocyanate groups in an aliphatic or aromatic compound, and has been widely used as a synthetic raw material for 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 formula can be suitably used, but are not limited thereto.

<Masking agent>
The modifier used in the production method of 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>
A modifier having at least one free isocyanate group and the other having a masked isocyanate group used in the present invention by reacting the organic polyisocyanate compound listed above with the masking agent listed above. Is synthesized. 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 by the specific modifier as described above of the present invention 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 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 used in the reaction between the epoxy compound as described above 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 methylene diamine, ethylene diamine, trimethylene diamine, 1,3-diaminopropane, hexamethylene diamine and octamethylene diamine; phenylene diamine, 3,3′-dichloro-4,4′-diaminodiphenyl methane, 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.

(Self-crosslinking type polyhydroxy polyurethane resin)
The self-crosslinking type polyhydroxypolyurethane resin of the present invention can be obtained by reacting the modifier and the polyhydroxypolyurethane resin obtained as described above. 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.

It is preferable that the modification | denaturation rate by the modifier of the self-crosslinking type polyhydroxy polyurethane resin of this invention is 2 to 60%. If the modification rate is less than 2%, sufficient crosslinking does not occur, so that 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 increases, which 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 should be noted that the reaction is carried out at a temperature lower than the dissociation temperature of the masking agent during the reaction, so that the synthesized polyhydroxypolyurethane resin has a masked isocyanate group in its structure.

(Use of self-crosslinking polyhydroxypolyurethane resin)
The self-crosslinking polyhydroxypolyurethane resin of the present invention obtained as described above can be used as it is as a film / molding material, various coating materials, various paints, various binders, etc. Products with excellent chemical and heat resistance can be obtained. In various applications and film formation, for the purpose of adjusting resin characteristics, etc., various known resins can be mixed as a binder resin and used as a resin material in the self-crosslinking polyhydroxypolyurethane resin. As the binder resin used in this case, a resin that can chemically react with an isocyanate group generated by dissociation of a masking portion in the structure of the self-crosslinking polyhydroxypolyurethane resin is preferable. However, even a resin having no reactivity as described above can be used as a resin material in combination with the self-crosslinking polyhydroxy polyurethane resin of the present invention as appropriate according to the purpose.

  As the binder resin that can be used in combination with the self-crosslinking type polyhydroxypolyurethane resin of the present invention, various conventionally used resins can be used and are not particularly limited. For example, acrylic resin, polyurethane resin, polyester resin, polybutadiene resin, silicone resin, melamine resin, phenol resin, polyvinyl chloride resin, cellulose resin, alkyd resin, modified cellulose resin, fluorine resin, polyvinyl butyral resin, epoxy resin, polyamide resin Etc. can be used. Also, resins obtained by modifying various resins with silicone or fluorine can be used. When these binder resins are used in combination, the amount used varies depending on the product to be prepared and the purpose of use, but is preferably 5 to 90 parts by weight, more preferably 100 parts by weight of the self-crosslinking polyhydroxy polyurethane resin of the present invention. 60 parts by mass or less may be added. Of course, the more the proportion of use of the self-crosslinking polyhydroxypolyurethane resin of the present invention, the more preferable the environmentally friendly product.

  In the self-crosslinking polyhydroxypolyurethane resin of the present invention, the masked portion is dissociated by heat treatment to generate an isocyanate group. And since the generated isocyanate group reacts with the hydroxyl group in the polyhydroxypolyurethane resin to form a crosslinked resin by self-crosslinking, it has excellent heat resistance, chemical resistance, Abrasion can be obtained. In addition, the polyhydroxypolyurethane resin used when synthesizing the self-crosslinking polyhydroxypolyurethane resin of the present invention is synthesized using a 5-membered cyclic carbonate compound. Since the compound is obtained by reacting an epoxy compound with carbon dioxide, it can be fixed by incorporating carbon dioxide into the resin. This means that according to the present invention, it is possible to provide an environmental protection material that is useful from the viewpoint of reducing greenhouse gases and that cannot be achieved by conventional products.

  The self-crosslinking polyhydroxypolyurethane resin of the present invention is very useful as various molding materials, synthetic leather and artificial leather materials, fiber coating materials, surface treatment materials, heat-sensitive recording materials, releasable materials, paints, binders for printing inks, etc. It is.

  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, 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%), add 32 parts of methyl ethyl ketoxime while stirring ethyl acetate well 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 (Horiba FT-720) of the obtained product (1-A), the peak derived from the epoxy group of the raw material in the vicinity of 910 cm ⁻¹ almost disappeared in the product, and 1,800 cm ^−1. Absorption of a carbonyl group of a cyclic carbonate group not present in the raw material was confirmed in the vicinity. 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)
Instead of the divalent epoxy compound A used in Production Example 4, a divalent epoxy compound represented by the following formula B (YDF-170 (trade name), manufactured by Tohto Kasei Co., Ltd., epoxy equivalent 172 g / mol) was used, and Production Example 4 to give 121 parts (yield 96%) of a white powder 5-membered cyclic carbonate compound (1-B).

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化合物（１−Ｂ）中には、２０．３％の二酸化炭素が固定化されていた。

The product was confirmed by infrared absorption spectrum, GPC and NMR as in Production Example 4. In the obtained 5-membered cyclic carbonate compound (1-B), 20.3% of carbon dioxide was immobilized.

<Example 1> (Production of self-crosslinking polyhydroxypolyurethane 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, the self-crosslinked polyhydroxypolyurethane resin solution of this example was obtained.

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

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

<Comparative 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 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 200 parts. Dissolved in a mixed organic solvent consisting of 50 parts of methyl ethyl ketone and 50 parts of 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. For 6 hours. This solution had a viscosity of 3.2 MPa · s (25 ° C.) at a solid content of 35%.

<Evaluation>
Using the resin solutions of Examples 1 to 4 and Comparative Examples 1 and 2, films were prepared by the casting method, and the following properties were measured for each of the obtained films. Casting conditions were: drying at 100 ° C. for 3 minutes and then heat treatment at 160 ° C. for 30 minutes.

[Mechanical properties (tensile strength, elongation)]
Each film was evaluated for mechanical properties (tensile strength, elongation) according to JIS K7311. The results are shown in Table 2.
[Thermal softening point]
About each film, the thermal softening point was evaluated according to JISK7206 (Vicat softening point measuring method). The results are shown in Table 2.
[Abrasion]
About each film, abrasion property was evaluated according to JISK7311. The results are shown in Table 2.
[Solvent resistance]
According to JIS K5600-6-1, the appearance change of each film before and after being immersed in toluene at 50 ° C. for 10 minutes was observed, and the solvent resistance was evaluated. The results are shown in Table 2.
[Environmental compatibility]
It evaluated by (circle) x by the presence or absence of the fixation of the carbon dioxide in each film. The results are shown in Table 2.

  From the above results, it was confirmed that sufficient self-crosslinking had progressed in the films obtained using the resins of Examples 1 to 4. Moreover, the self-crosslinking type polyhydroxy polyurethane resin of Examples 1 to 4 showed the same or better performance than the conventional polyester polyurethane resin.

  According to the present invention described above, a polyhydroxypolyurethane resin, which is a useful material considered to contribute to solving global warming, resource depletion, and the like, but whose application has not progressed, can be effectively used for industrial use. A cross-linked polyhydroxy polyurethane resin is provided. More specifically, according to the present invention, the formed product incorporates carbon dioxide and is an environmentally friendly product that can contribute to the reduction of greenhouse gases, but also has heat resistance, chemical resistance, wear resistance, etc. A self-crosslinked polyhydroxypolyurethane resin that is sufficiently satisfactory in terms of performance is provided.

Claims (7)

Self-crosslinked polyhydroxy, which is derived from a reaction between a 5-membered cyclic carbonate compound and a diamine , which is an amine compound (except for aminourethane) , and has a masked isocyanate group in its structure Polyurethane resin.   The self-crosslinking according to claim 1, wherein the 5-membered cyclic carbonate compound is a reaction product of an epoxy compound and carbon dioxide, and carbon dioxide is contained in the structure in an amount of 1 to 25% by mass. Type polyhydroxy polyurethane resin. The masked isocyanate group uses a modifier having at least one free isocyanate group and a masked isocyanate group, and the free isocyanate group of the modifier is converted into the 5-membered cyclic carbonate compound and the amine. By reacting with the hydroxyl group in the polyhydroxy polyurethane resin derived from the reaction with the compound, it has in its structure, and the masked part is dissociated by heat treatment to produce an isocyanate group, The self-crosslinking polyhydroxypolyurethane resin according to claim 1 or 2, which reacts with a hydroxyl group in the structure to self-crosslink. A method for producing a self-crosslinking polyhydroxypolyurethane resin according to any one of claims 1 to 3,
Using a modifier having at least one free isocyanate group and a masked isocyanate group, the free isocyanate group of the modifier is derived from the reaction of a 5-membered cyclic carbonate compound with a diamine , which is an amine compound. A process for producing a self-crosslinking polyhydroxypolyurethane resin comprising reacting with a hydroxyl group in a polyhydroxypolyurethane resin to obtain a polyhydroxypolyurethane resin having an isocyanate group masked in its structure.   The 5-membered cyclic carbonate compound is a reaction product of an epoxy compound and carbon dioxide, and 1 to 25% by mass of carbon dioxide in a polyhydroxy polyurethane resin derived from the reaction of the compound and an amine compound. The manufacturing method of the self-crosslinking type polyhydroxy polyurethane resin of Claim 4 included in the range.   6. The method for producing a self-crosslinking polyhydroxy polyurethane resin according to claim 4, wherein the modifier is a reaction product of an organic polyisocyanate compound and a masking agent.   A resin material obtained by mixing the self-crosslinking polyhydroxy polyurethane resin according to any one of claims 1 to 3 with another binder resin.