High-viscosity polyurethane adhesive and preparation method thereof

Abstract

The invention relates to a high-viscosity polyurethane adhesive, which is prepared from the following raw materials in parts by weight: 100 to 150 parts of polyurethane, 5 to 10 parts of 2, 4-toluene diisocynate, 20 to 30 parts of polyether solution and 30 to 40 parts of viscous aid. The invention also provides a preparation method of the high-viscosity polyurethane adhesive. The preparation method comprises the following steps: S1, preparing a polyether solution and a viscous auxiliary agent; s2, uniformly mixing polyurethane, 2, 4-toluene diisocynate, a polyether solution and a viscous auxiliary agent, stirring for 24 to 48 hours, and standing, so as to obtain the high-viscosity polyurethane adhesive. According to the high-viscosity polyurethane adhesive and the preparation method thereof disclosed by the invention, the prepared adhesive has good viscosity and mechanical properties.

Description

Technical Field

[0001] The invention relates to the field of adhesives, and in particular to a high-viscosity polyurethane adhesive and a preparation method thereof. Background Art

[0002] Polyurethane adhesives have gradually become indispensable adhesive products in the industry due to their high bonding strength and good water and medium resistance. Among them, the one-component moisture-curing polyurethane solvent-free adhesive has the characteristics of large molecular weight and high viscosity, but requires a higher operating temperature, and carbon dioxide is produced as a by-product during the curing process, and the composite film is prone to foaming. The two-component reactive polyurethane adhesive has the characteristics of small product molecular weight, low viscosity and low operating temperature, but it contains more free diisocyanates, and has the disadvantages of easy external pollution and low heat sealing strength. However, with the rapid development of the industry, the requirements for coated polyurethane adhesives are getting higher and higher. Therefore, it is necessary to improve the performance of polyurethane adhesives to meet the current market demand. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a high-viscosity polyurethane adhesive and a preparation method thereof, wherein the prepared adhesive has good viscosity and mechanical properties.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A high-viscosity polyurethane adhesive comprises the following raw materials in parts by weight: 100-150 parts of polyurethane, 5-10 parts of 2,4-toluene diisocyanate, 20-30 parts of polyether solution and 30-40 parts of viscosity aid.

[0006] Preferably, the following raw materials are included in parts by weight: 100 parts of polyurethane, 10 parts of 2,4-toluene diisocyanate, 20 parts of polyether solution and 40 parts of adhesion promoter.

[0007] A method for preparing a high-viscosity polyurethane adhesive comprises the following steps:

[0008] S1: preparing a polyether solution and a viscosity aid;

[0009] S2: After uniformly mixing polyurethane, 2,4-toluene diisocyanate, polyether solution and viscosity aid, stirring for 24-48 hours and letting stand, a high-viscosity polyurethane adhesive is obtained.

[0010] Preferably, the method for preparing the polyether solution in step S1 comprises:

[0011] Chitosan, amino polyether ED-600, acetic acid and 50% by mass of sodium citrate were mixed, and stirred at 35-40° C. for 1 hour to obtain a polyether solution.

[0012] Preferably, the weight ratio of the chitosan, amino polyether ED-600, acetic acid and sodium citrate is 1:1:1:2.

[0013] Preferably, the method for preparing the viscosity aid in step S1 comprises:

[0014] The modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and 75% tetramethylethylenediamine solution are mixed, stirred for 12-24 hours, polyvinyl alcohol and nano zinc oxide are added, and stirring is continued for 12-24 hours to obtain the viscosity aid.

[0015] Preferably, the weight ratio of the modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and nano zinc oxide is 1:2:1:3:4:5:2.

[0016] Preferably, the modified kaolin solution is prepared by mixing quaternary ammonium salt, kaolin and 50% by volume ethanol solution, and stirring at 30-40° C. for 4-6 hours to obtain the modified kaolin solution.

[0017] Preferably, the weight ratio of the quaternary ammonium salt, kaolin and ethanol solution is 1:2:5.

[0018] Preferably, the quaternary ammonium salt is didecyldimethylammonium chloride.

[0019] The polyurethane of the invention improves the space between components through the viscosity auxiliary agent, polyvinyl alcohol can grab and bind the dispersed nano zinc oxide, effectively load the quaternary ammonium salt in a cross-interlocking manner, improve the compactness and interface compatibility of the modified kaolin, achieve the purpose of strengthening and toughening, and reduce the void ratio of the viscosity auxiliary agent at the same time; the polyether solution has a large specific surface area, and the surface cross-linked long-chain chitosan is matched with the component space given by the viscosity auxiliary agent, which greatly improves the flexibility of the molecular chain, and at the same time can fill the gap and cross-link the viscosity auxiliary agent, so that the viscosity of the system is increased. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. In addition, it is specifically stated that the raw materials and equipment of the present invention can be obtained from commercial sources, and no longer listed one by one. Among them, the raw materials of the present invention can be obtained from commercial sources and are well known to those skilled in the art.

[0021] Embodiment 1:

[0022] A high-viscosity polyurethane adhesive comprises the following raw materials in parts by weight: 100 parts of polyurethane, 10 parts of 2,4-toluene diisocyanate, 20 parts of polyether solution and 40 parts of viscosity aid.

[0023] A method for preparing a high-viscosity polyurethane adhesive comprises the following steps:

[0024] S1: preparing a polyether solution: mixing chitosan, amino polyether ED-600, acetic acid and 50% sodium citrate in a weight ratio of 1:1:1:2, and stirring at 35° C. for 1 h to obtain a polyether solution;

[0025] Preparation of a viscosity aid: Mix a modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a 75% by volume tetramethylethylenediamine solution, stir for 24 hours, and then add polyvinyl alcohol and nano zinc oxide, wherein the weight ratio of the modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and nano zinc oxide is 1:2:1:3:4:5:2, and continue stirring for 24 hours to obtain the above-mentioned viscosity aid;

[0026] The preparation method of the modified kaolin solution is as follows: mixing didecyl dimethyl ammonium chloride, kaolin and 50% ethanol solution by volume in a weight ratio of 1:2:5, stirring at 40° C. for 6 hours to obtain the modified kaolin solution;

[0027] S2: After uniformly mixing the above-mentioned parts by weight of polyurethane, 2,4-toluene diisocyanate, polyether solution and viscosity aid, stirring for 48 hours and letting it stand, a high-viscosity polyurethane adhesive is obtained.

[0028] Embodiment 2:

[0029] A high-viscosity polyurethane adhesive comprises the following raw materials in parts by weight: 100 parts of polyurethane, 5 parts of 2,4-toluene diisocyanate, 20 parts of polyether solution and 30 parts of viscosity aid.

[0030] A method for preparing a high-viscosity polyurethane adhesive comprises the following steps:

[0031] S1: preparing a polyether solution: mixing chitosan, amino polyether ED-600, acetic acid and 50% sodium citrate in a weight ratio of 1:1:1:2, and stirring at 35° C. for 1 h to obtain a polyether solution;

[0032] Preparation of a viscosity aid: Mix a modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a 75% by volume tetramethylethylenediamine solution, stir for 12 hours, and then add polyvinyl alcohol and nano zinc oxide, wherein the weight ratio of the modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and nano zinc oxide is 1:2:1:3:4:5:2, and continue stirring for 12 hours to obtain the above-mentioned viscosity aid;

[0033] The preparation method of the modified kaolin solution is as follows: mixing didecyl dimethyl ammonium chloride, kaolin and 50% ethanol solution by volume in a weight ratio of 1:2:5, stirring at 30° C. for 4 hours to obtain the modified kaolin solution;

[0034] S2: After uniformly mixing the above-mentioned parts by weight of polyurethane, 2,4-toluene diisocyanate, polyether solution and viscosity aid, stirring for 24 hours and letting it stand, a high-viscosity polyurethane adhesive is obtained.

[0035] Embodiment 3:

[0036] A high-viscosity polyurethane adhesive comprises the following raw materials in parts by weight: 150 parts of polyurethane, 10 parts of 2,4-toluene diisocyanate, 30 parts of polyether solution and 35 parts of viscosity aid.

[0037] A method for preparing a high-viscosity polyurethane adhesive comprises the following steps:

[0038] S1: preparing a polyether solution: mixing chitosan, amino polyether ED-600, acetic acid and 50% sodium citrate in a weight ratio of 1:1:1:2, and stirring at 38° C. for 1 h to obtain a polyether solution;

[0039] Preparation of a viscosity aid: Mix a modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a 75% by volume tetramethylethylenediamine solution, stir for 20 hours, then add polyvinyl alcohol and nano zinc oxide, wherein the weight ratio of the modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and nano zinc oxide is 1:2:1:3:4:5:2, continue stirring for 18 hours, and obtain the above-mentioned viscosity aid;

[0040] The preparation method of the modified kaolin solution is as follows: mixing didecyl dimethyl ammonium chloride, kaolin and 50% ethanol solution by volume in a weight ratio of 1:2:5, stirring at 35° C. for 5 hours to obtain the modified kaolin solution;

[0041] S2: After uniformly mixing the above-mentioned parts by weight of polyurethane, 2,4-toluene diisocyanate, polyether solution and viscosity aid, stirring for 36 hours and letting it stand, a high-viscosity polyurethane adhesive is obtained.

[0042] Comparative Example 1:

[0043] The components of Comparative Example 1 are substantially the same as those of Example 1, except that no polyether solution is used, specifically:

[0044] A high-viscosity polyurethane adhesive comprises the following raw materials in parts by weight: 100 parts of polyurethane, 10 parts of 2,4-toluene diisocyanate and 40 parts of an adhesive auxiliary agent.

[0045] A method for preparing a high-viscosity polyurethane adhesive comprises the following steps:

[0046] S1: preparing a viscosity aid: mixing a modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and a 75% by volume tetramethylethylenediamine solution, stirring for 24 hours, and then adding polyvinyl alcohol and nano zinc oxide, wherein the weight ratio of the modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and nano zinc oxide is 1:2:1:3:4:5:2, and stirring is continued for 24 hours to obtain the above-mentioned viscosity aid;

[0047] The preparation method of the modified kaolin solution is as follows: mixing didecyl dimethyl ammonium chloride, kaolin and 50% ethanol solution by volume in a weight ratio of 1:2:5, stirring at 40° C. for 6 hours to obtain the modified kaolin solution;

[0048] S2: After uniformly mixing the above-mentioned parts by weight of polyurethane, 2,4-toluene diisocyanate and viscosity aid, stirring for 48 hours and letting it stand, a high-viscosity polyurethane adhesive is obtained.

[0049] Comparative Example 2:

[0050] The components of Comparative Example 2 are substantially the same as those of Example 1, except that no viscosity aid is used, specifically:

[0051] A high-viscosity polyurethane adhesive comprises the following raw materials in parts by weight: 100 parts of polyurethane, 10 parts of 2,4-toluene diisocyanate and 20 parts of polyether solution.

[0052] A method for preparing a high-viscosity polyurethane adhesive comprises the following steps:

[0053] S1: preparing a polyether solution: mixing chitosan, amino polyether ED-600, acetic acid and 50% sodium citrate in a weight ratio of 1:1:1:2, and stirring at 35° C. for 1 h to obtain a polyether solution;

[0054] S2: After uniformly mixing the above-mentioned parts by weight of polyurethane, 2,4-toluene diisocyanate and polyether solution, stirring for 48 hours and allowing to stand, a high-viscosity polyurethane adhesive is obtained.

[0055] Performance tests were performed on Examples 1 to 3 of the present invention, Comparative Example 1, Comparative Example 2 and a commercially available polyurethane adhesive from Dongguan Yantai Chemical Co., Ltd. The test results are shown in Table 1.

[0056] Peel strength: According to GB / T 8808-1988 "Peel test method for soft composite plastic materials", the PP / PE composite film is bonded and measured after 48 hours. The measuring speed is 300mm / min.

[0057] Water absorption rate: The adhesives prepared in the examples and comparative examples were weighed and placed in deionized water, soaked at room temperature for 24 h, taken out, wiped dry the water stains on the surface, weighed again, and the water absorption rate was calculated: water absorption rate = [(m1-m0) / m0] × 100%.

[0058] Viscosity: Test with reference to GB / T 2794-1995 "Determination of viscosity of adhesives".

[0059] Table 1 Test data of Examples 1-3, commercially available adhesives and Comparative Examples 1-2

[0060]

[0061] It can be seen from the above table that the polyurethane adhesives obtained in Examples 1-3 have high peel strength, low water absorption, and high viscosity.

[0062] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high viscosity polyurethane adhesive, characterized in that: The invention comprises the following raw materials in parts by weight: 100-150 parts of polyurethane, 5-10 parts of 2,4-toluene diisocyanate, 20-30 parts of polyether solution and 30-40 parts of viscosity auxiliary agent.

2. The high viscosity polyurethane adhesive according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of polyurethane, 10 parts of 2,4-toluene diisocyanate, 20 parts of polyether solution and 40 parts of viscosity aid.

3. A method for preparing a high-viscosity polyurethane adhesive as claimed in claim 1, characterized in that: The following steps are involved: S1: preparing a polyether solution and a viscosity aid; S2: After uniformly mixing polyurethane, 2,4-toluene diisocyanate, polyether solution and viscosity aid, stirring for 24-48 hours and letting stand, a high-viscosity polyurethane adhesive is obtained.

4. The method for preparing a high-viscosity polyurethane adhesive according to claim 3, characterized in that: The method for preparing the polyether solution in step S1 comprises: Chitosan, amino polyether ED-600, acetic acid and 50% by mass of sodium citrate were mixed, and stirred at 35-40° C. for 1 hour to obtain a polyether solution.

5. The method for preparing a high-viscosity polyurethane adhesive according to claim 4, characterized in that: The weight ratio of the chitosan, amino polyether ED-600, acetic acid and sodium citrate is 1:1:1:

2.

6. The method for preparing a high-viscosity polyurethane adhesive according to claim 3, characterized in that: The preparation method of the viscosity auxiliary agent in step S1 comprises: The modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate and 75% tetramethylethylenediamine solution are mixed, stirred for 12-24 hours, polyvinyl alcohol and nano zinc oxide are added, and stirring is continued for 12-24 hours to obtain the viscosity aid.

7. The method for preparing a high-viscosity polyurethane adhesive according to claim 6, characterized in that: The weight ratio of the modified kaolin solution, N-isopropylacrylamide monomer, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine solution, polyvinyl alcohol and nano zinc oxide is 1:2:1:3:4:5:

2.

8. The method for preparing a high-viscosity polyurethane adhesive according to claim 7, characterized in that: The preparation method of the modified kaolin solution is as follows: quaternary ammonium salt, kaolin and 50% ethanol solution by volume are mixed, and stirred at 30-40° C. for 4-6 hours to obtain the modified kaolin solution.

9. The method for preparing a high-viscosity polyurethane adhesive according to claim 8, characterized in that: The weight ratio of the quaternary ammonium salt, kaolin and ethanol solution is 1:2:

5.

10. The method for preparing a high-viscosity polyurethane adhesive according to claim 9, characterized in that: The quaternary ammonium salt is didecyl dimethyl ammonium chloride.

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