Polyurethane elastomer for highway expansion joint and preparation method thereof

Abstract

The invention discloses a polyurethane elastomer for highway expansion joints and a preparation method thereof, and belongs to the technical field of polyurethane adhesives. The technical scheme is as follows: it comprises a polyol component and an isocyanate component, wherein the polyol component comprises the following raw materials in parts by weight: 82 to 88.0 parts of polyol A, 9.2 to 14.6 parts of chain extender, 0.4 to 0.6 parts of antioxidant, 1.9 to 2.0 parts of water absorbent, and 0.2 to 0.3 parts of catalyst; the isocyanate component comprises the following raw materials in parts by weight: 39.0 to 55.2 parts of isocyanate, 42.8 to 58.7 parts of polyol B, and 0.5 to 3.0 parts of monoalcohol. The preparation method comprises the preparation of the polyol component, the preparation of the isocyanate component, and the mixing during use. The invention not only has high tearing and high elongation, but also has good adhesion, toughness and compression permanent deformation properties.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane adhesives, and in particular relates to a polyurethane elastomer for highway expansion joints and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of all walks of life in my country, the people's living standards have generally improved. In order to facilitate travel, the number of people using vehicles has increased day by day. Private cars, as one of the main modes of travel, have more and more sensory requirements on highway conditions, durability, stability, etc.

[0003] Traditional highways are connected by steel bars and concrete. Due to their strong rigidity, they are easily affected by factors such as high and low temperature differences, aging, and expansion and contraction, which can easily cause road surface defects or surface unevenness, increasing costs such as road repair and labor costs.

[0004] As a high-strength and high-toughness polymer material, polyurethane has great application prospects. Although people have developed some polyurethane sealing and other connection materials, due to its product characteristics, polyether materials are generally used outdoors. However, polyether materials have low tear strength, low elongation, and high compression permanent deformation, resulting in poor toughness and short service life of products, making it difficult to meet the long-term use requirements of sealing connections between highways. Summary of the invention

[0005] The invention provides a polyurethane elastomer for highway expansion joints and a preparation method thereof, which overcomes the problems of low tear strength and poor toughness of polyether prepolymers used in the prior art. The polyurethane elastomer for highway expansion joints of the invention has not only high tear strength and high elongation, but also good adhesion, toughness and compression permanent deformation performance.

[0006] The technical solution of the present invention is:

[0007] In a first aspect, a polyurethane elastomer for a highway expansion joint is disclosed, comprising a polyol component and an isocyanate component, wherein the polyol component and the isocyanate component are mixed in a weight ratio of 100:(100-130), wherein:

[0008] The polyol component comprises the following raw materials in parts by weight: 82-88.0 parts of polyol A, 9.2-14.6 parts of chain extender, 0.4-0.6 parts of antioxidant, 1.9-2.0 parts of water absorbent, and 0.2-0.3 parts of catalyst;

[0009] The isocyanate component includes the following raw materials in parts by weight:

[0010] 39.0 to 55.2 parts of isocyanate, 42.8 to 58.7 parts of polyol B, and 0.5 to 3.0 parts of monool.

[0011] Preferably, polyol A includes amine ether polyol, and also includes polyether polyol or polytetramethylene ether polyol; polyol B is polytetramethylene ether polyol.

[0012] Preferably, the amine ether polyol is prepared by reacting triisopropanolamine and propylene oxide, has a number average molecular weight of 540, and a functionality of 3.

[0013] Preferably, the chain extender is one of ethylene glycol and 1,4-butanediol, and the antioxidant is n-octadecyl propionate and N-(ethoxycarbonylphenyl)-N'-methyl-N'-phenylformamidine (UV-1).

[0014] Preferably, the water absorbent is 3A molecular sieve produced by Dalian Haixin Chemical Co., Ltd.

[0015] Preferably, the catalyst is bismuth neodecanoate or an amine composite catalyst.

[0016] Preferably, the monoalcohol is prepared by reacting tetrahydrofuran and n-butanol, has a number average molecular weight of 290, and a functionality of 1.

[0017] Preferably, the isocyanate is diphenylmethane diisocyanate or carbodiimide-modified isocyanate.

[0018] In a second aspect, a method for preparing the polyurethane elastomer for highway expansion joints is disclosed, comprising the following steps:

[0019] 1) Preparation of polyol components

[0020] Add polyether polyol or polytetrahydrofuran ether polyol and antioxidant into a reactor, raise the temperature to 100-120°C, dehydrate until the water content is less than 0.5‰, and then add amine ether polyol, chain extender, water absorbent and catalyst after cooling to 60-65°C and stirring for 1-2h to obtain a polyol component;

[0021] 2) Preparation of isocyanate component

[0022] First, polyol B and monool are heated to 100-120°C, dehydrated to a water content of less than 0.5‰, then cooled to 50-55°C, isocyanate is added to the reactor, heated to 80-90°C for 2-4 hours, and air bubbles are removed by vacuum to obtain an isocyanate component having an isocyanate mass content of 10.0-17.0%;

[0023] 3) When using, mix the polyol component and the isocyanate component in a weight ratio of 100: (100-130) and place at room temperature for 7-14 days.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Adding monoalcohol to the polyurethane elastomer for highway expansion joints of the present invention can significantly improve the tearing property and elongation of the elastomer and greatly improve the toughness of the product.

[0026] 2. In addition to adding monoalcohol, the present invention also introduces amine ether polyol, which has a small amount of functionality and branched chains, and can improve the compression permanent deformation performance of the product while improving the adhesion between the elastomer and the steel plate.

[0027] 3. The polyurethane elastomer for highway expansion joints prepared by the present invention can be operated at high temperature, has sufficient operating time, good fluidity and is easy to operate.

[0028] 4. The preparation method of the present invention has simple and reasonable process, readily available raw materials, and is convenient for industrial production. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] The parameters of the raw materials used are as follows:

[0031] CD-C: carbodiimide modified isocyanate, number average molecular weight 300, Covestro Polymers China Co., Ltd.;

[0032] MDI-100: diphenylmethane diisocyanate, number average molecular weight 250, Yantai Wanhua Chemical Group Co., Ltd.

[0033] DL2000: number average molecular weight 2000, functionality 2, polyether polyol, Shandong Yinuowei New Materials Co., Ltd.;

[0034] PTMG2000: number average molecular weight 2000, functionality 2, polytetramethylene ether polyol, Hyosung Chemical Co., Ltd.

[0035] PTMG3000: number average molecular weight 3000, functionality 2, polytetramethylene ether polyol, Hyosung Chemical Co., Ltd.

[0036] NJ6209: number average molecular weight 588, functionality 4, polyether polyol, Ningwu Jurong New Materials Co., Ltd.

[0037] HX-G103: water absorbent, 3A molecular sieve, Dalian Haixin Chemical Co., Ltd.;

[0038] Bismuth neodecanoate, Taixing Shengling Co., Ltd.;

[0039] KZ-14: number average molecular weight 90, functionality 2, 1,4-butanediol, Zhejiang Sunrise Fine Chemical Co., Ltd.;

[0040] TMP: number average molecular weight 135, functionality 3, trimethylolpropane, Jiangsu Dalton Petrochemical Technology Co., Ltd.;

[0041] 1076: Antioxidant, n-octadecyl propionate, Tianjin Lisheng Chemical Co., Ltd.;

[0042] UV-1: antioxidant, N-(ethoxycarbonylphenyl)-N'-methyl-N'-phenylformamidine, Dalian New Sunshine Material Technology Co., Ltd.

[0043] A33: Amine compound catalyst, the main ingredient is triethylenediamine, Shanghai Kain Chemical Co., Ltd.

[0044] Preparation method of monoalcohol: 100g of n-butanol is added to a reactor, and after N2 replacement, stirring is started and the temperature is raised to 100°C. 44g of tetrahydrofuran is first added to the reactor to start the reaction. When the reactor pressure drops from 0.32MPa to 0.15MPa, heating is stopped, and cooling water is introduced for cooling. 248g of tetrahydrofuran is added to the reactor, and the temperature is controlled not to exceed 110°C. The reaction is carried out at 105°C. When the reactor pressure drop is zero, the reactor is cooled down, and the qualified discharge is carried out after it drops to room temperature. The number average molecular weight of the monoalcohol product is 290, and the functionality is 1.

[0045] The preparation method of amine ether polyol K-540 is as follows: 100g of triisopropanolamine is added to a reactor, and after N2 replacement, stirring is started and the temperature is raised to 90°C. 36.4g of propylene oxide is first added to the reactor to start the reaction. When the reactor pressure drops from 0.3MPa to 0.15MPa, heating is stopped, and cooling water is introduced to cool the reactor to prevent overheating. 145.6g of propylene oxide is added to the reactor, and the temperature is controlled not to exceed 100°C. The reaction is carried out at 95°C. When the reactor pressure drop is zero, the reactor is cooled. After cooling to room temperature, samples are taken for analysis, and the material is discharged after passing the test. The product has a number average molecular weight of 540 and a functionality of 3.

[0046] Example 1

[0047] The method for preparing the polyurethane elastomer for highway expansion joints comprises the following steps:

[0048] 1) Preparation of polyol components:

[0049] The total weight of the polyol component is 100 parts by weight. First, 85.9 parts of PTMG2000, 0.3 parts of UV-1 and 0.3 parts of 1076 are added to the reactor, the temperature is raised to 100°C, dehydrated to a moisture content of less than 0.5‰, and then added to 11.1 parts of KZ-14, 0.3 parts of K-540, 1.9 parts of HX-G103, and 0.2 parts of A33 after the temperature is lowered to 60°C, and stirred for 1 hour to obtain the polyol component;

[0050] 2) Preparation of isocyanate component

[0051] The total weight of the isocyanate component is 100 parts by weight. First, 48.7 parts of PTMG2000 and 1.0 part of monoalcohol are heated to 100°C, dehydrated to a water content of less than 0.5‰, then cooled to 50°C, 50.3 parts of MDI-100 are added to the reactor, heated to 80°C and kept for 4 hours, and the bubbles are removed by vacuum to obtain an isocyanate component with an isocyanate mass content of 14.7%;

[0052] 3) When using, mix the polyol component and the isocyanate component in a weight ratio of 100:100 and leave it at room temperature for 7 days to achieve the performance.

[0053] Example 2

[0054] The method for preparing the polyurethane elastomer for highway expansion joints comprises the following steps:

[0055] 1) Preparation of polyol components

[0056] The total weight of the polyol component is 100 parts by weight. First, 85.9 parts of PTMG2000, 0.3 parts of UV-1 and 0.3 parts of 1076 are added to the reactor, heated to 120°C, dehydrated to a moisture content of less than 0.5‰, and then added to 65°C. 11.1 parts of KZ-14, 0.3 parts of K-540, 1.9 parts of HX-G103, and 0.2 parts of A33 are stirred for 2 hours to obtain the polyol component;

[0057] 2) Preparation of isocyanate component

[0058] The total weight of the isocyanate component is 100 parts by weight. First, 46.2 parts of PTMG2000 and 2.9 parts of monoalcohol are heated to 120°C, dehydrated to a water content of less than 0.5‰, then cooled to 52°C, 50.9 parts of MDI-100 are added to the reactor, heated to 90°C and kept for 2 hours, and the bubbles are removed by vacuum to obtain an isocyanate component with an isocyanate mass content of 14.7%;

[0059] When in use, the polyol component and the isocyanate component are mixed in a weight ratio of 100:100 and left at room temperature for 14 days to achieve the desired performance.

[0060] Example 3

[0061] The method for preparing the polyurethane elastomer for highway expansion joints comprises the following steps:

[0062] 1) Preparation of polyol components

[0063] The total weight of the polyol component is 100 parts by weight. First, 85.9 parts of PTMG2000, 0.3 parts of UV-1 and 0.3 parts of 1076 are added to the reactor, heated to 110°C, dehydrated to a moisture content of less than 0.5‰, and then added to 62°C. 11.1 parts of KZ-14, 0.3 parts of K-540, 1.9 parts of HX-G103, and 0.2 parts of A33 are stirred for 1.5 hours to obtain the polyol component;

[0064] 2) Preparation of isocyanate component

[0065] The total weight of the isocyanate component is 100 parts by weight. First, 50.5 parts of PTMG3000 and 1.0 parts of monoalcohol are heated to 115°C, dehydrated to a water content of less than 0.5‰, then cooled to 52°C, 48.5 parts of MDI-100 are added to the reactor, heated to 85°C and kept for 3 hours, and the bubbles are removed by vacuum to obtain an isocyanate component with an isocyanate mass content of 14.7%;

[0066] When in use, the polyol component and the isocyanate component are mixed in a weight ratio of 100:100 and left at room temperature for 10 days to achieve the desired performance.

[0067] Example 4

[0068] The method for preparing the polyurethane elastomer for highway expansion joints comprises the following steps:

[0069] 1) Preparation of polyol components

[0070] The total weight of the polyol component is 100 parts by weight. First, 84.6 parts of DL2000, 0.3 parts of UV-1 and 0.3 parts of 1076 are added to the reactor, the temperature is raised to 100°C, dehydrated to a water content of less than 0.5‰, and then added to 12.2 parts of KZ-14, 0.5 parts of K-540, 1.9 parts of HX-G103, and 0.2 parts of A33 after the temperature is lowered to 60°C, and stirred for 1 hour to obtain the polyol component;

[0071] 2) Preparation of isocyanate component

[0072] The total weight of the isocyanate component is 100 parts by weight. First, 46.2 parts of PTMG2000 and 2.0 parts of monoalcohol are heated to 100°C, dehydrated to a water content of less than 0.5‰, then cooled to 50°C, 41.4 parts of MDI-100 and 10.4 parts of CD-C are added to the reactor, heated to 80°C and kept for 4 hours, and the bubbles are removed by vacuum to obtain an isocyanate component with an isocyanate mass content of 14.7%;

[0073] 3) When using, mix the polyol component and the isocyanate component in a weight ratio of 100:100 and leave it at room temperature for 7 days to achieve the performance.

[0074] Example 5

[0075] The method for preparing the polyurethane elastomer for highway expansion joints comprises the following steps:

[0076] 1) Preparation of polyol components

[0077] The total weight of the polyol component is 100 parts by weight. First, 87.5 parts of PTMG2000, 0.2 parts of UV-1 and 0.2 parts of 1076 are added to the reactor, the temperature is raised to 100°C, dehydrated to a water content of less than 0.5‰, and then 9.3 parts of KZ-14, 0.3 parts of K-540, 0.2 parts of NJ6209, 2.0 parts of HX-G103, and 0.3 parts of A33 are added after the temperature is lowered to 60°C and stirred for 1 hour to obtain the polyol component;

[0078] 2) Preparation of isocyanate component

[0079] The total weight of the isocyanate component is 100 parts by weight. First, 58.7 parts of PTMG2000 and 2.3 parts of monoalcohol are heated to 100°C, dehydrated to a water content of less than 0.5‰, then cooled to 50°C, 39.0 parts of MDI-100 are added to the reactor, heated to 80°C and kept for 4 hours, and the bubbles are removed by vacuum to obtain an isocyanate component with an isocyanate mass content of 10.0%;

[0080] 3) When using, mix the polyol component and the isocyanate component in a weight ratio of 100:130 and leave it at room temperature for 14 days to achieve the desired performance.

[0081] Example 6

[0082] The method for preparing the polyurethane elastomer for highway expansion joints comprises the following steps:

[0083] 1) Preparation of polyol components

[0084] The total weight of the polyol component is 100 parts by weight. First, 82.2 parts of PTMG2000, 0.3 parts of UV-1 and 0.2 parts of 1076 are added to the reactor, the temperature is raised to 120°C, dehydrated to a water content of less than 0.5‰, and then 14.6 parts of propylene glycol, 0.5 parts of K-540, 2.0 parts of HX-G103, and 0.2 parts of a bismuth catalyst are added after the temperature is lowered to 65°C and stirred for 2 hours to obtain a polyol component;

[0085] 2) Preparation of isocyanate component

[0086] The total weight of the isocyanate component is 100 parts by weight. First, 42.9 parts of PTMG2000 and 2.2 parts of monoalcohol are heated to 120°C, dehydrated to a water content of less than 0.5‰, then cooled to 55°C, 54.9 parts of MDI-100 are added to the reactor, heated to 90°C and kept for 2 hours, and the bubbles are removed by vacuum to obtain an isocyanate component with an isocyanate mass content of 16.1%;

[0087] 3) When using, mix the polyol component and the isocyanate component in a weight ratio of 100:125 and leave it at room temperature for 10 days to achieve the desired performance.

[0088] Comparative Example 1

[0089] The preparation method of polyurethane elastomer comprises the following steps:

[0090] 1) Preparation of polyol components

[0091] The total weight of the polyol component is 100 parts by weight. First, 85.9 parts of PTMG2000, 0.3 parts of UV-1 and 0.3 parts of 1076 are added to the reactor, heated to 100°C, dehydrated to a moisture content of less than 0.5‰, and then added to 11.1 parts of KZ-14, 0.3 parts of TMP, 1.9 parts of HX-G103, and 0.2 parts of A33 after the temperature drops to 60°C, and stirred for 1 hour to obtain the polyol component;

[0092] 2) Preparation of isocyanate component

[0093] The total weight of the isocyanate component is 100 parts by weight. First, 50.0 parts of PTMG2000 are heated to 100°C, dehydrated to a water content of less than 0.5‰, then cooled to 50°C, 50.0 parts of MDI-100 are added to the reactor, heated to 80°C and kept for 4 hours, and the bubbles are removed by vacuum to obtain an isocyanate component with an isocyanate mass content of 14.7%;

[0094] 3) When using, mix the polyol component and the isocyanate component in a weight ratio of 100:100 and leave it at room temperature for 7 days to achieve the performance.

[0095] Comparative Example 2

[0096] The difference from Example 1 is that in this comparative example, "0.3 parts of K-540" is replaced by "0.3 parts of TMP", and the rest of the preparation methods and steps are the same as those in Example 1.

[0097] Comparative Example 3

[0098] Different from Example 4, in this comparative example, "0.5 parts of K-540" is replaced by "0.5 parts of TMP", and the rest of the preparation methods and steps are the same as those in Example 4.

[0099] Comparative Example 4

[0100] Different from Example 1, step 2) in this comparative example is: the preparation of the isocyanate component is calculated by weight, and the total weight of the isocyanate component is 100 parts. First, 50.0 parts of PTMG2000 are heated to 100°C, dehydrated to a moisture content of less than 0.5‰, then cooled to 50°C, 50.0 parts of MDI-100 are added to the reactor, the temperature is raised to 80°C and kept for 4 hours, and the bubbles are removed by vacuum to obtain an isocyanate component with an isocyanate mass content of 14.7%; the remaining preparation methods and steps are the same as those in Example 1.

[0101] The polyurethane elastomers prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were subjected to performance tests, and the specific test standards are as follows:

[0102] The hardness is tested in accordance with GB / T531-1999 Rubber Pocket Hardness Tester Indentation Hardness Test Method.

[0103] The tensile strength and elongation at break are tested in accordance with GB / T 528-2009 Method for Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber;

[0104] Determination of peel strength: According to GB / T 2792 1998 Test method for 180° peel strength of pressure-sensitive adhesive tape, the sample width is 25mm, and the steel materials are clamped on the BLD-2005 electronic peeling machine for testing. The loading speed is 5mm / s and the test temperature is 25℃.

[0105] Compression set determination: Test in accordance with GB / T 7759.1-2015 Determination of compression set of vulcanized rubber or thermoplastic rubber.

[0106] The performance test results of the polyurethane elastomers prepared in Examples 1 to 6 and Comparative Examples 1 to 4 are shown in Table 1.

[0107] Table 1 Performance indicators of elastomers prepared in Examples 1 to 6 and Comparative Examples 1 to 4

[0108]

[0109] The results in Table 1 show that the introduction of amine ether polyols and monoalcohols into polyurethane elastomers can significantly improve the elongation and tear properties of the product, while also having good compression set and bonding properties.

[0110] Compared with Comparative Example 1, the elongation of Example 1 is increased from 474% to 624%, the trouser-type tear is increased from 24.5 N / mm to 37.3 N / mm, the peel strength is significantly improved, and the compression permanent deformation is better. This is because the introduction of monoalcohols reduces the system functionality, improves the toughness of the product, and increases its elongation; at the same time, the introduction of amine ether polyols forms a new cross-linked network structure, which reduces the deformation performance of the product; at the same time, since the amine ether polyols have side chains, their adhesion to steel can be improved; compared with Comparative Example 4, the elongation of Example 1 is increased from 476% to 624%, and the trouser-type tear is increased from 22.9 N / mm to 37.3 N / mm. This is because, in Comparative Example 4, when only amine ether polyols are added, although a new cross-linked network structure is formed to reduce the deformation performance of the product, it cannot improve the toughness of the product and its elongation.

[0111] Compared with Example 2 and Example 3, when adding monoalcohol at the same time, the basic performance changes little, the compression permanent deformation decreases by nearly 36%, and the peel strength increases by 30-40%. This is because the introduction of amine ether polyol improves its bonding performance due to its branched chain, forms a new cross-linked network structure, and reduces the deformation of the product. At the same time, the rules of the two systems of polytetrahydrofuran ether polyol and polyether polyol are basically the same, indicating that amine ether polyol is applicable in both systems.

[0112] Compared with Comparative Example 1, the elongation of Example 2 is increased from 474% to 750%, and the trouser-type tear resistance is increased from 24.5 N / mm to 45.5 N / mm. This is mainly because the amount of monoalcohol is increased appropriately, which can improve the elongation and trouser-type tear resistance of the product. At the same time, the compression permanent deformation remains basically unchanged, and the peel strength is slightly improved. This is because in Example 2, a certain amount of amine ether polyol is added to make up for the defects of introducing monoalcohol, and the compression permanent deformation performance of the product is improved by forming different cross-linked network structures.

Claims

1. Polyurethane elastomer for highway expansion joints, characterized in that: It includes a polyol component and an isocyanate component, which are mixed in a weight ratio of 100: (100-130), wherein: The polyol component comprises the following raw materials in parts by weight: 82-88.0 parts of polyol A, 9.2-14.6 parts of chain extender, 0.4-0.6 parts of antioxidant, 1.9-2.0 parts of water absorbent, and 0.2-0.3 parts of catalyst; The isocyanate component includes the following raw materials in parts by weight: 39.0-55.2 parts of isocyanate, 42.8-58.7 parts of polyol B, 0.5-3.0 parts of monool; Polyol A includes amine ether polyol or polytetramethylene ether polyol; polyol B is polytetramethylene ether polyol; Amine ether polyol is prepared by the reaction of triisopropanolamine and propylene oxide, with a number average molecular weight of 540 and a functionality of 3; The monoalcohol is prepared by the reaction of tetrahydrofuran and n-butanol, with a number average molecular weight of 290 and a functionality of 1.

2. The polyurethane elastomer for highway expansion joints according to claim 1, characterized in that: The chain extender is one of ethylene glycol and 1,4-butanediol, and the antioxidant is n-octadecyl propionate and N-(ethoxycarbonylphenyl)-N'-methyl-N'-phenylformamidine.

3. The polyurethane elastomer for highway expansion joints according to claim 1, characterized in that: The water absorbent is 3A molecular sieve.

4. The polyurethane elastomer for highway expansion joints according to claim 1, characterized in that: The catalyst is bismuth neodecanoate or an amine compound catalyst.

5. The polyurethane elastomer for highway expansion joints according to claim 1, characterized in that: The isocyanate is diphenylmethane diisocyanate or carbodiimide-modified isocyanate.

6. The method for preparing a polyurethane elastomer for a highway expansion joint according to any one of claims 2 to 5, characterized in that: The following steps are involved: 1) Preparation of polyol components Add polytetrahydrofuran ether polyol and antioxidant into the reactor, raise the temperature to 100-120°C, dehydrate until the water content is less than 0.5‰, and then add amine ether polyol, chain extender, water absorbent and catalyst after cooling to 60-65°C and stirring for 1-2h to obtain polyol component; 2) Preparation of isocyanate component First, polyol B and monool are heated to 100-120°C, dehydrated to a water content of less than 0.5‰, then cooled to 50-55°C, isocyanate is added to the reactor, heated to 80-90°C for 2-4 hours, and air bubbles are removed by vacuum to obtain an isocyanate component having an isocyanate mass content of 10.0-17.0%; (3) When in use, mix the polyol component and the isocyanate component in a weight ratio of 100:(100-130) and leave at room temperature for 7-14 days.

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