Polyurethane coating

Abstract

To provide a polyurethane resin suitable for the production of polyurethane coatings having a high modulus of elasticity. [Solution] The polyurethane resin of the present invention is manufactured from raw materials containing polycarbonate diol, diol, and isocyanate, wherein the polycarbonate diol contains repeating units represented by the following formulas (A) and (B), and the repeating units represented by formula (B) account for more than 10 mol% and up to 30 mol% of the polycarbonate diol. JPEG2026098873000023.jpg16169 JPEG2026098873000024.jpg19169 In formula (B), A is a C3-20 alicyclic hydrocarbon or a structure represented by formula (C). JPEG2026098873000025.jpg25169

Description

Technical Field

[0001] The present invention relates to a polyurethane resin and a polyurethane film produced using the polyurethane resin.

Background Art

[0002] A polyurethane resin is a polymer material having a urethane bond, and is mainly produced by reacting an isocyanate functional group (-N=C=O) with a hydroxy group (-OH). In commercial production, generally, isocyanate is reacted with a mixture containing a polyol and a catalyst or the like to produce polyurethane.

[0003] Regarding the polyol used in the production of polyurethane, it has been proposed to use a polycarbonate diol as the polyol. This is an oligomer having hydroxy groups at both ends of the molecule, and is mainly used to form soft segments in polyurethane. The polyurethane produced using this is mainly applied to uses such as thermoplastic elastomers and foams.

[0004] For example, Taiwan Patent No. I673298B discloses a polycarbonate diol and a polyurethane foam produced using the polycarbonate diol, and thus, a polyurethane foam having a high specific strength (foaming ratio × pressure resistance strength) can be produced.

[0005] However, the above-mentioned Taiwan Patent No. I673298B mainly conducts research on the production of polyurethane foams using polycarbonate diols, and does not describe polyurethane films having a high elastic modulus. More specifically, the above-mentioned patent document widely discloses that the molar ratio range of the following formulas (A) and (B) in the polycarbonate diol is from 1:99 to 99:1, but does not discuss the influence of the molar ratio of formulas (A) and (B) on the elastic modulus of the polyurethane film.

[0006] Therefore, there is still room for improvement in polyurethane resins suitable for producing polyurethane coatings with a high modulus of elasticity. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Taiwan Patent No. I673298B Specification [Overview of the project] [Problems that the invention aims to solve]

[0008] In view of the above-mentioned conventional problems, the object of the present invention is to provide a polyurethane resin applicable to the production of polyurethane coatings having a high modulus of elasticity. [Means for solving the problem]

[0009] A polyurethane resin according to one aspect of the present invention is manufactured from raw materials containing a polycarbonate diol, a diol, and an isocyanate, wherein the polycarbonate diol contains repeating units represented by the following formulas (A) and (B), and the repeating units represented by formula (B) constitute a proportion greater than 10 mol% and up to 30 mol% of the polycarbonate diol. [ka] [ka] In formula (A), R1 is a linear, branched, or cyclic C2-20 alkylene group; in formula (B), R2 is a linear or branched C2-10 alkylene group; m and n are integers from 0 to 10, and m+n≧1; and A is a C3-20 alicyclic hydrocarbon or a structure represented by formula (C) below. [ka] In formula (C), R3 and R4 are each independently a hydrogen atom or a C1-6 alkyl group, S is 1, and B is

Chemical formula

[0010] In one embodiment, the diol is at least one selected from the group consisting of propylene glycol, butanediol, pentanediol, and hexanediol.

[0011] In one embodiment, the molar ratio of the polycarbonate diol to the diol is from 8:2 to 2:8.

[0012] In one embodiment, the number average molecular weight (M n ) of the polycarbonate diol is from 500 to 5000.

[0013] In one embodiment, in formula (A), R1 is a butylene group or a hexylene group.

[0014] In one embodiment, in formula (B), R2 is a C2-3 alkylene group.

[0015] In one embodiment, in formula (B), A is

Chemical formula

[0016] In one embodiment, in formula (B), 1 ≦ m + n ≦ 10.

[0017] In one embodiment, the repeating unit represented by the formula (B) accounts for 14.5 mol% to 25 mol% of the polycarbonate diol.

[0018] To solve the above-mentioned problems, a polyurethane coating according to one aspect of the present invention is manufactured from the aforementioned polyurethane resin, and the elastic modulus of the polyurethane coating is greater than 90 MPa. [Modes for carrying out the invention]

[0019] The methods for carrying out the present invention will be described below with reference to specific embodiments. Those familiar with the art will be able to understand the other advantages and effects of the present invention from the contents disclosed herein. The present invention can also be carried out or applied by other different specific embodiments, and each detail herein can be modified and altered in various ways without departing from the spirit of the invention, based on different viewpoints and applications.

[0020] Unless otherwise stated in the text, the term "A to B" used in the specification and claims includes the meaning of "greater than or equal to A and less than or equal to B." For example, the term "10 to 40% by weight" includes the meaning of "10% by weight or more and 40% by weight or less."

[0021] First, the polyurethane resin of the present invention is manufactured using liquid polycarbonate diol, diol, and isocyanate at room temperature as raw materials. Each component will be described in detail below.

[0022] [Polycarbonate diol] The polycarbonate diol contains repeating units derived from two types of diols, formula (A) and formula (B), of which the repeating units of formula (B) are derived from an alkoxylated diol monomer, and the proportion of formula (B) in the polycarbonate diol structure is greater than 10 mol% and up to 30 mol%, preferably 14.5 mol% to 25 mol%, more preferably 20 mol%.

[0023] Of these, equation (A) is [ka] In formula (A), R1 is a linear, branched, or cyclic C2-20 alkylene group. According to some specific examples, R1 may be a butylene or hexylene group such as an n-butylene group, tert-butylene group, n-hexylene group, or sec-hexylene group.

[0024] Also, equation (B) is [ka] In formula (B), R2 is a linear or branched C2-10 alkylene group, m and n are integers from 0 to 10, and m+n≧1, and A is a C3-20 alicyclic hydrocarbon or a structure represented by the following formula (C). [ka] In formula (C), R3 and R4 are each independent hydrogen atoms or C1-6 alkyl groups, S is 1, and B is [ka] Selected from, Of these, R5 and R6 are either independent hydrogen atoms or C1-C12 alkyl groups.

[0025] Specifically, R2 in formula (B) may be an alkylene group of C2-3, such as an ethylene group or a propylene group. Also, m+n in formula (B) is ≥1 to ≤20, preferably 1 ≤ m+n ≤ 10. In addition, A in formula (B) is [ka] That's fine.

[0026] In some examples, the alkoxylated diol monomer used to form the repeating unit represented by formula (B) includes 2-bis[4-(2-hydroxyethoxy)cyclohexyl]-propane, 2-bis[4-(2-hydroxyethoxy)phenyl]-propane, 2-[4-(2-hydroxyethoxy)cyclohexyl]-2-[4-(2-hydroxydiethoxy)cyclohexyl]-propane, or 2-[4-(2-hydroxyethoxy)phenyl]-2-[4-(2-hydroxydiethoxy)phenyl]-propane. More specifically, the alkoxylated diol monomer used to form the repeating unit represented by formula (B) has the structure represented by the following formula (E): [ka] In this case, both m and n in formula (E) are equal to 1, and in the following examples, the structure represented by formula (E) is represented by HBPA-EO2.

[0027] Here, polycarbonate diol is produced by the following process. First, a transesterification reaction is carried out using a diol monomer and dialkyl carbonate to separate the compound containing the hydroxyl group from the dialkyl carbonate, thereby obtaining a polycarbonate prepolymer. Subsequently, the compound containing the hydroxyl group, unreacted diol monomer, unreacted dialkyl carbonate, etc., are removed, and the polycarbonate prepolymer is subjected to a condensation reaction to obtain a polycarbonate diol.

[0028] Furthermore, based on some examples of the present invention, a polycarbonate diol having two types of repeating units, formula (A) and formula (B), is formed by performing the transesterification reaction described above using a diol monomer, the above-mentioned alkoxylated diol monomer, and a dialkyl carbonate. Among these, the diol monomer may have a structure represented by formula (D). [ka] In formula (D), R7 may be a linear, branched, or cyclic alkylene group of C2 to C20, such as a butylene group or a hexylene group. For example, diol monomers having the structure of formula (D) may include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,4-butanediol, 2-isopropyl-1,4-butanediol, 1,5-pentanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,3-cyclic hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, or 2-bis(4-hydroxycyclohexyl)-propane.

[0029] In addition, the dialkyl carbonate used in the aforementioned transesterification reaction may include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, or dibutyl carbonate. According to some examples of the present invention, the transesterification reaction is carried out using dimethyl carbonate.

[0030] In some examples, the number average molecular weight (M) of the polycarbonate diol was n ) is 500 to 5000, preferably 800 to 1500.

[0031] [Diol] Diols are essential components in the manufacture of polyurethane resins and are mainly used as chain extenders. At least one diol selected from the group consisting of propylene glycol, butanediol, pentanediol, and hexanediol can be used. In some embodiments of the present invention, butanediol (BDO) is used, which is a small molecule (molecular weight 90.1 g / mol) and does not contain an ether group, making it suitable for use as a chain extender. Furthermore, the molar ratio of the polycarbonate diol to the diol is preferably between 8:2 and 2:8.

[0032] [Isocyanate] Isocyanates are essential components in the manufacture of polyurethane resins and are mainly used as curing agents. Conventional diisocyanates such as toluene diisocyanate and 4,4'-diphenylmethane diisocyanate can be used. In some embodiments of the present invention, 4,4'-diphenylmethane diisocyanate (MDI) is used. In some embodiments, the molar ratio of the polycarbonate diol to the isocyanate is approximately 0.55:1.

[0033] [Method for manufacturing polyurethane resin] One method for producing the polyurethane resin involves, for example, adding a polycarbonate diol and a diol together to a solvent, dissolving them uniformly, and then adding an isocyanate to carry out the reaction. Preferably, the reaction is carried out at a temperature of 30 to 100°C for 0.5 to 10 hours. This reaction can also be carried out in a mixed solvent of dimethylformamide / toluene / methyl ethyl ketone.

[0034] [Method for manufacturing polyurethane coating] As a method for producing the polyurethane film, for example, the obtained polyurethane resin solution is applied to a release PET film with a 300 μm doctor blade, and then dried in an oven at 80°C for 24 hours to obtain a polyurethane film with a thickness of 50 to 60 μm. In the examples of the present invention, the elastic modulus of the polyurethane film is greater than 90 MPa, preferably greater than 200 MPa, and more preferably greater than 500 MPa.

[0035] [Examples] The present invention will be described in detail below through various examples and comparative examples, but the present invention is not limited to these examples and comparative examples.

[0036] [Hydroxyl value (OH value) of polycarbonate diols] Based on the ASTME1899 standard, the titration mode was set to DET mode, the electrode used was a Metrohm Solvotrode easyClean 6.0229.010, and the titrant was 0.1M tetrabutylammonium hydroxide (TBAOH) mixed with isopropyl alcohol (IPA) / methanol (MeOH) (50 / 50). The solution was prepared using v / v) solution, and a solution of isocyanate-p-toluenesulfonyl (TSI) was prepared (approximately 250 ml of acetonitrile was placed in a 500 ml volumetric flask, 20 ml of TSI was added, and then acetonitrile was added up to the 500 ml mark and mixed uniformly). The TBAOH solution was standardized (180 mg of potassium bituminous phthalate (KHP) was dissolved in 60 ml of deionized water, and then titrated with 0.1 M TBAOH). After preparing the sample (an appropriate amount of the sample was dissolved in 10 ml of acetonitrile, then 10 ml of TSI solution was added and stirred, then 0.5 ml of deionized water was added and stirred, and finally 40 ml of acetonitrile was added). Finally, the hydroxyl value of the sample was obtained by automatic titration.

[0037] [Number-average molecular weight of polycarbonate diols] Number-average molecular weight (Mn) = 2 / (Hydroxyl value × 10) -3 / 56.11)

[0038] [Tensile test of polyurethane (PU) coating] The mechanical properties of the PU coating were measured using a universal testing machine in accordance with the ASTM D882 standard. The properties of the film (thickness ≤ 100 μm) were primarily measured, including tensile strength (maximum stress), elongation at break, and elastic modulus. The purpose was to evaluate and compare the tensile strength of the material and its applicable range. A strip-shaped test specimen (dimensions 150 mm × 12.5 mm), a grip spacing of 100 mm, and a clip separation speed of 50 mm / min were used.

[0039] [Acid resistance, alkali resistance, and hydrolysis resistance tests of PU coatings] After cutting the PU coating test pieces to the appropriate dimensions to fit the containers holding the solutions, hydrolysis resistance, acid resistance, and alkali resistance tests were performed according to the following conditions: a. Hydrolysis resistance test: Immersion in 100°C water for 24 hours. b. Acid resistance test: Immersion in 0.1M H2SO4 for 24 hours. c. Alkali resistance test: Immersion in 0.1M NaOH for 24 hours.

[0040] In Table 5, described below, O indicates no change in weight (no disassembly) and no damage to the appearance, △ indicates no change in weight (no disassembly), but with slight warping or deformation to the appearance, and X indicates no change in weight (no disassembly), but with severe warping, deformation and stickiness to the appearance.

[0041] [Manufacturing of polycarbonate diols] [Examples]

[0042] In a glass round-bottom flask equipped with a stirrer, thermometer, nitrogen inlet tube, and tail gas cooling condensation system, 1371 g of dimethyl carbonate (DMC), 1111 g of 1,4-butanediol (BDO), 450 g of ethoxylated 2-bis(4-hydroxycyclohexyl)-propane (hereinafter referred to as HBPA-EO2), and 137 mg of tetrabutoxytitanium catalyst were placed. Under atmospheric pressure and nitrogen gas flow conditions, the raw materials in the round-bottom flask were stirred, and the by-product mixture of methanol and dimethyl carbonate was removed by distillation while the transesterification reaction was carried out for 14 hours. During this process, the reaction temperature slowly rose from 120°C to 170°C.

[0043] Next, the pressure was reduced to 10 torr, and the by-products methanol, unreacted dimethyl carbonate, and unreacted BDO were removed by distillation at 180°C while the condensation reaction was carried out for 10 hours. After the reaction was complete, the reaction solution was cooled to room temperature to obtain 997 g of a viscous liquid, i.e., the polycarbonate diol copolymer PC-1 of Example 1. Subsequently, the obtained polycarbonate diol copolymer PC-1 was measured using the test method described above. Its number-average molecular weight was 883, its hydroxyl value was 127 mg KOH / g, and HBPA-EO2 accounted for 14.5 mol% of the polycarbonate diol. [Examples]

[0044] The procedure was the same as in Example 1, except that the raw materials added were changed to 1219 g of dimethyl carbonate (DMC), 933 g of 1,4-butanediol (BDO), 600 g of ethoxylated 2-bis(4-hydroxycyclohexyl)-propane (HBPA-EO2), and 129 mg of tetrabutoxytitanium catalyst. This yielded 1115 g of a viscous liquid, i.e., the polycarbonate diol copolymer PC-2 of Example 2. Subsequently, PC-2 was measured using the test method described above. Its number-average molecular weight was 850, its hydroxyl value was 132 mg KOH / g, and HBPA-EO2 accounted for 20.0 mol% of the polycarbonate diol. [Examples]

[0045] The procedure was the same as in Example 2, except that the condensation reaction time was changed to 11 hours and BDO was removed to control the molecular weight of the polycarbonate diol copolymer, yielding 1113.6 g of a viscous liquid, i.e., the polycarbonate diol copolymer PC-3 of Example 3. Subsequently, PC-3 was measured using the test method described above. Its number-average molecular weight was 1122, its hydroxyl value was 100 mg KOH / g, and HBPA-EO2 accounted for 20.0 mol% of the polycarbonate diol. [Examples]

[0046] Except for changing the raw materials used, which were 92 g of dimethyl carbonate (DMC), 70 g of 1,4-butanediol (BDO), 45 g of ethoxylated 2-bis(4-hydroxycyclohexyl)-propane (HBPA-EO2), and 10.2 mg of tetrabutoxytitanium catalyst, the procedure was the same as in Example 1, yielding 85 g of a viscous liquid, i.e., the polycarbonate diol copolymer PC-4 of Example 4. Subsequently, PC-4 was measured using the test method described above. Its number-average molecular weight was 1181, its hydroxyl value was 95 mg KOH / g, and HBPA-EO2 accounted for 24.2 mol% of the polycarbonate diol. [Examples]

[0047] The procedure was the same as in Example 1, except that the raw materials added were changed to 69 g of dimethyl carbonate (DMC), 50 g of 1,4-butanediol (BDO), 45 g of ethoxylated 2-bis(4-hydroxycyclohexyl)-propane (HBPA-EO2), and 10.2 mg of tetrabutoxytitanium catalyst. 65 g of a viscous liquid, i.e., the polycarbonate diol copolymer PC-5 of Example 5, was obtained. Subsequently, PC-5 was measured using the test method described above. Its number-average molecular weight was 1496, its hydroxyl value was 75 mg KOH / g, and HBPA-EO2 accounted for 30.3 mol% of the polycarbonate diol. Comparative Example 1

[0048] In a glass round-bottom flask equipped with a distillation column, stirrer, thermometer, nitrogen inlet tube, and tail gas cooling condensation system, 963 g of dimethyl carbonate (DMC), 1200 g of 1,6-hexanediol (hereinafter referred to as HDO), and 51 mg of tetrabutoxytitanium catalyst were placed. Under atmospheric pressure and nitrogen gas flow conditions, the raw materials in the round-bottom flask were stirred, and the by-product mixture of methanol and dimethyl carbonate was removed by distillation while the transesterification reaction was carried out for 38 hours. During this process, the reaction temperature slowly rose from 120°C to 160°C.

[0049] Subsequently, the pressure was slowly reduced to 10 torr, and while stirring, the unreacted mixture of methanol and dimethyl carbonate and the unreacted hexanediol were removed by distillation. At the same time, the condensation reaction was carried out at 180°C for a further 27 hours. After the reaction was complete, the reaction solution was cooled to room temperature to obtain 932 g of solid polycarbonate diol copolymer PC-S1 of Comparative Example 1. Subsequently, PC-S1 was measured according to the test method described above. Its number-average molecular weight was 1122, and its hydroxyl value was 100 mgKOH / g. Comparative Example 2

[0050] In a glass round-bottom flask equipped with a distillation column, stirrer, thermometer, nitrogen inlet tube, and tail gas cooling condensation system, 1930 g of dimethyl carbonate (DMC), 1202 g of 1,6-hexanediol (HDO), 1060 g of 1,5-pentanediol (hereinafter referred to as PDO), and 67 mg of tetrabutoxytitanium catalyst were placed. Under atmospheric pressure and nitrogen gas flow conditions, the raw materials in the round-bottom flask were stirred, and the by-product mixture of methanol and dimethyl carbonate was removed by distillation while the transesterification reaction was carried out for 20 hours. During this process, the reaction temperature slowly rose from 120°C to 160°C.

[0051] Subsequently, the pressure was slowly reduced to 10 torr, and while stirring, the unreacted mixture of methanol and dimethyl carbonate, as well as the unreacted hexanediol and pentanediol, were removed by distillation. At the same time, the condensation reaction was carried out at 180°C for a further 7 hours. After the reaction was complete, the reaction solution was cooled to room temperature to obtain 1066 g of liquid polycarbonate diol copolymer PC-S2 of Comparative Example 2. Subsequently, PC-S2 was measured according to the test method described above. Its number-average molecular weight was 1001, and its hydroxyl value was 112 mgKOH / g. Comparative Example 3

[0052] The procedure was the same as in Example 1, except that the raw materials added were changed to 1219 g of dimethyl carbonate (DMC), 1050 g of 1,4-butanediol (BDO), 300 g of ethoxylated 2-bis(4-hydroxycyclohexyl)-propane (HBPA-EO2), and 129 mg of tetrabutoxytitanium catalyst. This yielded 1115 g of a viscous liquid, i.e., the polycarbonate diol copolymer PC-6 of Comparative Example 3. Subsequently, PC-6 was measured using the test method described above. Its number-average molecular weight was 1020, its hydroxyl value was 110 mg KOH / g, and HBPA-EO2 accounted for 10.0 mol% of the polycarbonate diol. Comparative Example 4

[0053] The procedure was the same as in Example 1, except that the raw materials added were changed to 55 g of dimethyl carbonate (DMC), 38 g of 1,4-butanediol (BDO), 45 g of ethoxylated 2-bis(4-hydroxycyclohexyl)-propane (HBPA-EO2), and 6.4 mg of tetrabutoxytitanium catalyst. This yielded 62 g of a viscous liquid, i.e., the polycarbonate diol copolymer PC-7 of Comparative Example 4. Subsequently, PC-7 was measured using the test method described above. Its number-average molecular weight was 927, its hydroxyl value was 121 mg KOH / g, and HBPA-EO2 accounted for 52.6 mol% of the polycarbonate diol.

[0054] Next, the experimental results for Examples 1-5 and Comparative Examples 1-4 described above are summarized in Tables 1 and 2.

[0055] [Table 1]

[0056] [Table 2]

[0057] As can be seen from Tables 1 and 2 above, by adding ethoxylated-2-bis(4-hydroxycyclohexyl)-propane (HBPA-EO2) to polycarbonate diol, the crystallinity of 1,6-hexanediol or 1,4-butanediol is destroyed, and the resulting polycarbonate diol can be made liquid at room temperature. Therefore, when applied to the production of polyurethane resins and coatings, it can be made more convenient to handle.

[0058] [Manufacturing of polyurethane coatings] [Examples]

[0059] 4 g of polycarbonate diol (PC-1) obtained in Example 1 was mixed uniformly with 0.27 g of BDO and 6.34 g of solvent (dimethylformamide / toluene / methyl ethyl ketone = 20 / 40 / 40), and then 2.07 g of 4,4'-diphenylmethane diisocyanate (MDI) was added. The mixture was reacted in a 75°C water bath for 1 hour. The resulting polyurethane solution was then applied to a release PET film using a 300 μm doctor blade and subsequently dried in an 80°C oven for 24 hours to obtain a polyurethane film PU-1 with a thickness of 50-60 μm. After cutting, a tensile test (ASTM D882) was performed. The results are shown in Tables 3 and 4. [Examples]

[0060] 4 g of polycarbonate diol (PC-2) obtained in Example 2 was mixed uniformly with 0.28 g of BDO and 6.44 g of solvent (dimethylformamide / toluene / methyl ethyl ketone = 20 / 40 / 40), and then 2.16 g of 4,4'-diphenylmethane diisocyanate (MDI) was added, and the reaction was carried out in a 75°C water bath for 1 hour. Subsequently, the same procedure as in Example 6 was followed to obtain a polyurethane film PU-2 with a thickness of 50-60 μm, which was then cut and subjected to a tensile test. The results are shown in Tables 3 and 4. [Examples]

[0061] 4 g of polycarbonate diol (PC-3) obtained in Example 3 was mixed uniformly with 0.28 g of BDO and 6.44 g of solvent (dimethylformamide / toluene / methyl ethyl ketone = 20 / 40 / 40), and then 1.64 g of 4,4'-diphenylmethane diisocyanate (MDI) was added, and the reaction was carried out in a 75°C water bath for 1 hour. Subsequently, the same procedure as in Example 6 was followed to obtain a polyurethane film PU-3 with a thickness of 50-60 μm. After cutting this film, a tensile test was performed. The results are shown in Tables 3 and 4. [Examples]

[0062] 4 g of polycarbonate diol (PC-4) obtained in Example 4 was mixed uniformly with 0.15 g of BDO and 5.55 g of solvent (dimethylformamide / toluene / methyl ethyl ketone = 20 / 40 / 40), and then 1.41 g of 4,4'-diphenylmethane diisocyanate (MDI) was added and the mixture was reacted in a 75°C water bath for 1 hour. Subsequently, the same procedure as in Example 6 was followed to obtain a polyurethane coating PU-4 with a thickness of 50-60 μm. After cutting this coating, a tensile test was performed. The results are shown in Tables 3 and 4. [Examples]

[0063] To 4 g of the polycarbonate diol (PC-5) obtained in Example 5, 0.11 g of BDO and 5.15 g of solvent (dimethylformamide / toluene / methyl ethyl ketone = 20 / 40 / 40) were added and mixed uniformly. Subsequently, 1.05 g of 4,4'-diphenylmethane diisocyanate (MDI) was added, and the reaction was carried out in a 75°C water bath for 1 hour. After that, the same procedure as in Example 6 was followed to obtain a polyurethane coating PU-5 with a thickness of 50-60 μm. After cutting this film, a tensile test was performed. The results are shown in Tables 3 and 4. Comparative Example 5

[0064] To 4 g of polycarbonate diol (PC-S1) obtained in Comparative Example 1, 0.21 g of BDO and 5.85 g of solvent (dimethylformamide / toluene / methyl ethyl ketone = 20 / 40 / 40) were added and mixed uniformly. Subsequently, 1.64 g of 4,4'-diphenylmethane diisocyanate (MDI) was added, and the reaction was carried out in a 75°C water bath for 1 hour. After that, the same procedure as in Example 6 was followed to obtain a polyurethane coating PU-S1 with a thickness of 50-60 μm. After cutting this film, a tensile test was performed. The results are shown in Tables 3 and 4. Comparative Example 6

[0065] To 4 g of polycarbonate diol (PC-S2) obtained in Comparative Example 2, 0.24 g of BDO and 6.07 g of solvent (dimethylformamide / toluene / methyl ethyl ketone = 20 / 40 / 40) were added and mixed uniformly. Subsequently, 1.83 g of 4,4'-diphenylmethane diisocyanate (MDI) was added, and the reaction was carried out in a 75°C water bath for 1 hour. After that, the same procedure as in Example 6 was followed to obtain a polyurethane film PU-S2 with a thickness of 50-60 μm. After cutting this film, a tensile test was performed. The results are shown in Tables 3 and 4. Comparative Example 7

[0066] The only difference from Comparative Example 6 was that 4g of polycarbonate diol (PC-S2) used in Comparative Example 6 was replaced with 4g of polycarbonate diol (PC-6) used in Comparative Example 3. The procedure was the same as in Comparative Example 6, and a polyurethane coating PU-6 with a thickness of 50-60 μm was obtained. After cutting this coating, a tensile test was performed. The results are shown in Tables 3 and 4. Comparative Example 8

[0067] 4 g of polycarbonate diol (PC-7) obtained in Comparative Example 4 was mixed homogeneously with 0.17 g of BDO and 5.93 g of solvent (dimethylformamide / toluene / methyl ethyl ketone = 20 / 40 / 40), and then 1.72 g of 4,4'-diphenylmethane diisocyanate (MDI) was added, and the reaction was carried out in a 75°C water bath for 1 hour. The resulting polyurethane solution was applied to a release PET film with a 300 μm doctor blade and then dried in an 80°C oven for 24 hours, but no film was formed.

[0068] [Table 3]

[0069] [Table 4]

[0070] As can be seen from Tables 1 to 4 above, the HBPA-EO2 in Examples 1 to 5 is greater than 10 mol% of the polycarbonate diol and is within the range of up to 30 mol%. Therefore, the polycarbonate diols in Examples 1 to 5 can be used to produce polyurethane coatings PU-1, PU-2, PU-3, PU-4, and PU-5 (see Examples 6 to 10) with elastic moduli of 98, 566, 540, 337, and 209 MPa, respectively. In contrast, Comparative Examples 1 and 2 use a polycarbonate diol with a general carbon chain aliphatic structure (e.g., 1,6-hexanediol), so the elastic moduli of the polyurethane coatings PU-S1 and PU-S2 (see Comparative Examples 5 and 6) produced are only 22 and 16 MPa, respectively, which does not meet the needs.

[0071] Furthermore, in Comparative Example 3, HBPA-EO2 accounts for 10 mol.% of the polycarbonate diol, and its elastic modulus does not differ significantly from that of Comparative Example 5, which does not contain HBPA-EO2 (see Comparative Example 7). Therefore, it can be seen that if the molar ratio of HBPA-EO2 in the polycarbonate diol is too low (10 mol.% or less), it does not have a significant benefit to the strength of the polyurethane coating.

[0072] Next, in Comparative Example 4, HBPA-EO2 accounts for 52.6 mol. of polycarbonate diol (see Comparative Example 8), which exceeds the scope of application of the present invention, and therefore a polyurethane film cannot be obtained.

[0073] As can be seen from this, polycarbonate diols that contain the repeating unit of formula (B) and whose content is greater than 10 mol% and up to 30 mol% (preferably 14.5 mol% to 25 mol%) of the polycarbonate diol have higher material rigidity, the deformation that occurs under the action of external forces on the material is relatively small, and are advantageous for applications in products that require rigidity.

[0074] Finally, the above-described acid resistance, alkali resistance, and hydrolysis resistance tests were performed on the polyurethane coatings of Examples 6 and 7 and Comparative Example 5, and the results are shown in Table 5.

[0075] [Table 5]

[0076] As can be seen from Table 5, polyurethane coatings made from three different types of polycarbonate diols exhibited a certain degree of hydrolysis resistance, acid resistance, and alkali resistance. However, after immersion in 100°C hot water, the polyurethane coating made from aliphatic polycarbonate diol (PU-S1) showed severe deformation and stickiness, resulting in an X. Polyurethane coatings made from polycarbonate diols containing a specific ratio of HBPA-EO2 (PU-1 and PU-2) showed only slight warping, resulting in a △. Therefore, it was found that polyurethane coatings made from polycarbonate diols containing a specific ratio of HBPA-EO2 exhibit superior performance in terms of temperature resistance.

[0077] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of the present invention. [Explanation of symbols]

[0078] none

Claims

1. Polyurethane resin, The polyurethane resin is manufactured using raw materials containing polycarbonate diol, diol, and isocyanate. The polycarbonate diol contains repeating units represented by the following formulas (A) and (B), and the repeating units represented by formula (B) constitute a proportion of the polycarbonate diol greater than 10 mol% and up to 30 mol%, 【Chemistry 1】 【Chemistry 2】 In equation (A), R １ These are linear, branched, or cyclic C2-20 alkylene groups. In equation (B), R ２ is a linear or branched C2-10 alkylene group, m and n are integers from 0 to 10, and m + n ≥ 1, and A is a C3-20 alicyclic hydrocarbon or a structure represented by the following formula (C), 【Transformation 3】 In equation (C), R ３ and R ４ Each is an independent hydrogen atom or a C1-6 alkyl group, S is 1, and B is 【Chemistry 4】 Selected from, Eventually, R ５ and R ６ A polyurethane resin characterized in that each of these is an independent hydrogen atom or a C1-C12 alkyl group.

2. The polyurethane resin according to claim 1, characterized in that the diol is selected from at least one of the group consisting of propylene glycol, butanediol, pentanediol, and hexanediol.

3. The polyurethane resin according to claim 1 or 2, characterized in that the molar ratio of the polycarbonate diol to the diol is 8:2 to 2:

8.

4. The number average molecular weight (M) of the polycarbonate diol. ｎ The polyurethane resin according to claim 1 or 2, characterized in that the ratio is 500 to 5000.

5. In equation (A), R １ The polyurethane resin according to claim 1 or 2, characterized in that the group is a butylene group or a hexylene group.

6. In formula (B), R ２ The polyurethane resin according to claim 1 or 2, wherein is an alkylene group having 2 to 3 carbon atoms.

7. In equation (B), A is 【Transformation 5】 The polyurethane resin according to claim 1 or 2, characterized in that it is the same as the polyurethane resin according to claim 1 or 2.

8. The polyurethane resin according to claim 1 or 2, characterized in that in formula (B), 1 ≤ m + n ≤ 10.

9. The polyurethane resin according to claim 1 or 2, characterized in that the repeating unit represented by formula (B) accounts for 14.5 mol% to 25 mol% of the polycarbonate diol.

10. A polyurethane coating manufactured from the polyurethane resin described in claim 1 or 2, characterized in that the elastic modulus of the polyurethane coating is greater than 90 MPa.

Images