A two-component polyurethane adhesive with high tensile shear performance and its preparation process

Abstract

The present invention provides a two-component polyurethane adhesive with high tensile shear performance and a preparation process thereof, belonging to the technical field of polyurethane adhesives. Wherein, the two-component polyurethane adhesive with high tensile shear performance includes component A and component B; in terms of mass fractions, wherein: the raw material composition of component A includes: 50-60 parts of isocyanate prepolymer, 5-7 parts of silanized glass fiber whiskers, 3-5 parts of amino-type nano silicon nitride, 2-3 parts of cationized cellulose nanofibers, and 8-10 parts of benzyl alcohol diluent; the raw material composition of component B includes: 50-60 parts of polyester polyol, 5-10 parts of chain extender, 0.1-0.5 parts of catalyst, and 0.5-2 parts of antioxidant. The two-component polyurethane adhesive provided by the present invention has high tensile shear strength, is a new type of polyurethane adhesive product, and has a wide range of applications.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane adhesives, in particular to a two-component polyurethane adhesive with high tensile shear performance and a preparation process thereof. Background Art

[0002] Polyurethane adhesives are an important component of polyurethane resins and are widely used in the field of structural bonding due to their excellent shear strength and impact resistance. Since their discovery in the 1940s, polyurethane adhesives have continued to develop technologically and their application areas have become increasingly extensive. The core reaction mechanism of polyurethane adhesives is that isocyanate groups react chemically with substances containing active hydrogen to form polyurethane groups. This reaction gives polyurethane adhesives high strength and flexibility. Its main components include isocyanates and polyols, and by adjusting the proportions and types of these components, different application requirements can be met. Polyurethane adhesives, especially two-component polyurethane adhesives, play an important role in modern industry due to their excellent performance and wide application areas.

[0003] At present, there is a greater demand for the tensile shear strength of polyurethane adhesives in the market. In order to enrich the variety of products on the market, it is necessary to develop new polyurethane adhesive products. Summary of the invention

[0004] In order to solve the problems mentioned in the background technology, the present invention provides a two-component polyurethane adhesive with high tensile shear performance, which achieves high tensile shear performance through the synergistic effect between special components and has a wide range of applications.

[0005] Specifically:

[0006] A two-component polyurethane adhesive with high tensile shear performance, comprising component A and component B; in parts by mass, wherein:

[0007] The raw materials of component A include: 50-60 parts of isocyanate prepolymer, 5-7 parts of silanized glass fiber whiskers, 3-5 parts of amino-treated nano silicon nitride, 2-3 parts of cationic cellulose nanofibers, and 8-10 parts of benzyl alcohol diluent;

[0008] The raw material composition of component B includes: 50-60 parts of polyester polyol, 5-10 parts of chain extender, 0.1-0.5 parts of catalyst and 0.5-2 parts of antioxidant.

[0009] Furthermore, the isocyanate prepolymer is selected from toluene diisocyanate prepolymer, isophorone diisocyanate prepolymer, diphenylmethane diisocyanate prepolymer or lysine diisocyanate prepolymer.

[0010] Furthermore, the length of the cationized cellulose nanofibers is 200-800 nm.

[0011] Furthermore, the length of the silanized glass fiber whiskers is 50-80 μm.

[0012] Furthermore, the polyester polyol is polycarbonate diol.

[0013] Furthermore, the chain extender is selected from 1,4-butanediol or glycerol.

[0014] Furthermore, the catalyst is selected from dibutyltin diacetate or dibutyltin dilaurate.

[0015] Furthermore, when used, component A and component B are mixed in a mass ratio of 1:1; curing conditions: curing at room temperature for 10-12 hours, and then heating to 80-85°C for curing for 1-2 hours.

[0016] On the other hand, the present invention also provides a process for preparing the above-mentioned two-component polyurethane adhesive with high tensile shear performance, wherein:

[0017] The preparation steps of component A include: mixing isocyanate prepolymer and benzyl alcohol diluent at 40° C. at 400-500 rpm for 15-20 minutes; adding silanized glass fiber shreds and treating them with a high-speed disperser at 2000-2500 rpm for 20-30 minutes; adding amino-modified nano silicon nitride and cationic cellulose nanofibers in three batches, with an interval of 5-6 minutes between each batch, treating them with a three-roll mill, repeating three times, and packaging them independently;

[0018] The preparation steps of component B include: mixing polyester polyol, chain extender, catalyst and antioxidant, and then independently packing after ultrasonic dispersion.

[0019] Furthermore, the silanized glass fiber whiskers are treated by immersing the glass fiber whiskers in a 5% KH-550 ethanol solution, wherein the mass ratio of ethanol to water is 9:1, and the pH value is 4.5, and the solution is refluxed at 80° C. for 3 h, and then centrifuged to dry.

[0020] The treatment method of amino-treated nano silicon nitride is as follows: disperse nano silicon nitride in toluene, control the solid content to 10%, add 3-aminopropyltriethoxysilane, the mass ratio of nano silicon nitride to 3-aminopropyltriethoxysilane is 1:0.2, react under nitrogen protection at 110°C for 6 hours, centrifuge, wash and dry;

[0021] The treatment method of cationic cellulose nanofibers is as follows: disperse the cellulose nanofibers in deionized water at a mass ratio of 1:20, add 2,3-epoxypropyltrimethylammonium chloride, the mass ratio of cellulose nanofibers to 2,3-epoxypropyltrimethylammonium chloride is 1:0.9, adjust the pH to 5 with acetic acid, react at 60°C for 12 hours, dialysis purification, and freeze-drying.

[0022] Compared with the prior art, the present invention has the following beneficial features:

[0023] The two-component polyurethane adhesive with high tensile shear performance of the present invention introduces silanized glass fiber whiskers, amino-treated nano silicon nitride (Si 3 N 4 ) and cationic cellulose nanofibers (CNF); the surface of glass fiber whiskers was modified by silanization to form Si-O-Si covalent bonds with the polyurethane matrix to enhance the interfacial bonding strength; the cationic CNF wrapped the amino Si 3 N 4 Particles, constructing nanoscale CNF-Si 3 N 4 In the network, CNF is coupled with the polyurethane matrix through hydrogen bonds. When resisting external stress, the glass fiber acts as a rigid skeleton and directly bears the shear stress through oriented arrangement. At the same time, the cross-scale interpenetrating structure formed by the glass fiber (micrometer level) and CNF (nanometer level) realizes efficient stress transmission, and CNF then evenly distributes the stress to Si 3 N 4 particles and polyurethane matrix; in addition, the glass fiber initiates crack deflection, dissipates energy, and Si 3 N 4 The particles prevent crack propagation through the pinning effect, and CNF delays fracture through fibrillation and bridging effect. The three complement each other to improve the tensile shear strength of polyurethane adhesive. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In order to facilitate those skilled in the art to implement the present invention, some of the reagents used in the embodiments and comparative examples are now described:

[0026] Isocyanate prepolymer: toluene diisocyanate prepolymer, Shandong Maofa Chemical;

[0027] Benzyl alcohol diluent: BOC New Materials;

[0028] Polyester polyol: polycarbonate diol, Nanjing Xinhuayuan Chemical;

[0029] Chain extender: 1,4-butanediol, Shandong Ruigang Chemical;

[0030] Catalyst: dibutyltin dilaurate, Shandong Zhijia Chemical;

[0031] Antioxidant: Antioxidant 1010, Jinan Haiyuan Chemical;

[0032] Glass fiber whiskers: Wuhe County Weijia composite materials, chopped to 50-80μm, and the aspect ratio is controlled at 10-15 by ball milling;

[0033] KH-550 (3-aminopropyltriethoxysilane): Jinan Silicon Harbor Chemical;

[0034] Nano silicon nitride: Qinghe County Xingxin New Materials Technology, 5nm;

[0035] Cellulose nanofiber: Hubei Kemaidi Chemical, 200nm;

[0036] 2,3-Epoxypropyltrimethylammonium chloride: Hubei Shineng Chemical.

[0037] Preparation of silanized glass fiber whiskers: immerse the glass fiber whiskers in 5% KH-550 ethanol solution, the mass ratio of ethanol to water is 9:1, pH=4.5, reflux at 80°C for 3h, and centrifuge to dry. The length of the silanized glass fiber whiskers obtained is 50-80μm.

[0038] Preparation of amino-modified nano silicon nitride: disperse nano silicon nitride in toluene, control the solid content to 10%, add 3-aminopropyltriethoxysilane, the mass ratio of nano silicon nitride to 3-aminopropyltriethoxysilane is 1:0.2, react at 110°C under nitrogen protection for 6 hours, centrifuge, wash and dry;

[0039] Preparation of cationic cellulose nanofibers: Disperse cellulose nanofibers in deionized water at a mass ratio of 1:20, add 2,3-epoxypropyltrimethylammonium chloride, the mass ratio of cellulose nanofibers to 2,3-epoxypropyltrimethylammonium chloride is 1:0.9, adjust the pH to 5 with acetic acid, react at 60°C for 12h, dialysis purification, and freeze-drying. The obtained cationized cellulose nanofibers have a length of 200nm.

[0040] In order to verify the beneficial effects of the present invention, the following examples and comparative examples were designed to carry out experimental tests.

[0041] Example 1

[0042] A two-component polyurethane adhesive with high tensile shear performance, comprising component A and component B; in parts by mass, wherein:

[0043] The raw materials of component A include: 50 parts of isocyanate prepolymer, 5 parts of silanized glass fiber whiskers, 5 parts of amino-treated nano silicon nitride, 3 parts of cationic cellulose nanofibers, and 10 parts of benzyl alcohol diluent;

[0044] The raw material composition of component B includes: 50 parts of polyester polyol, 5 parts of chain extender, 0.5 parts of catalyst and 2 parts of antioxidant.

[0045] The preparation steps of component A include: mixing the isocyanate prepolymer and the benzyl alcohol diluent at 40°C at 400 rpm for 20 minutes; adding silanized glass fiber shreds and treating them with a high-speed disperser at 2000 rpm for 30 minutes; adding amino-modified nano silicon nitride and cationic cellulose nanofibers in three batches, with an interval of 5 minutes between each batch, treating them with a three-roll grinder, repeating three times, and packaging them independently;

[0046] The preparation steps of component B include: mixing polyester polyol, chain extender, catalyst and antioxidant, and then independently packing after ultrasonic dispersion.

[0047] Example 2

[0048] A two-component polyurethane adhesive with high tensile shear performance, comprising component A and component B; in parts by mass, wherein:

[0049] The raw materials of component A include: 60 parts of isocyanate prepolymer, 7 parts of silanized glass fiber whiskers, 3 parts of amino-treated nano silicon nitride, 2 parts of cationic cellulose nanofibers, and 10 parts of benzyl alcohol diluent;

[0050] The raw material composition of component B includes: 60 parts of polyester polyol, 10 parts of chain extender, 0.1 parts of catalyst and 0.5 parts of antioxidant.

[0051] The preparation steps of component A include: mixing the isocyanate prepolymer and the benzyl alcohol diluent at 40°C at 500 rpm for 15 minutes; adding silanized glass fiber shreds and treating them with a high-speed disperser at 2500 rpm for 20 minutes; adding amino-modified nano silicon nitride and cationic cellulose nanofibers in three batches, with an interval of 6 minutes between each batch, treating them with a three-roll grinder, repeating three times, and packaging them independently;

[0052] The preparation steps of component B include: mixing polyester polyol, chain extender, catalyst and antioxidant, and then independently packing after ultrasonic dispersion.

[0053] Example 3

[0054] A two-component polyurethane adhesive with high tensile shear performance, comprising component A and component B; in parts by mass, wherein:

[0055] The raw materials of component A include: 60 parts of isocyanate prepolymer, 7 parts of silanized glass fiber whiskers, 5 parts of amino-treated nano silicon nitride, 3 parts of cationic cellulose nanofibers, and 8 parts of benzyl alcohol diluent;

[0056] The raw material composition of component B includes: 60 parts of polyester polyol, 10 parts of chain extender, 0.1 parts of catalyst and 0.5 parts of antioxidant.

[0057] The preparation steps of component A include: mixing the isocyanate prepolymer and the benzyl alcohol diluent at 40°C at 500 rpm for 20 minutes; adding silanized glass fiber shreds and treating them with a high-speed disperser at 2500 rpm for 30 minutes; adding amino-modified nano silicon nitride and cationic cellulose nanofibers in three batches, with an interval of 6 minutes between each batch, treating them with a three-roll grinder, repeating three times, and packaging them independently;

[0058] The preparation steps of component B include: mixing polyester polyol, chain extender, catalyst and antioxidant, and then independently packing after ultrasonic dispersion.

[0059] Comparative Example 1

[0060] A two-component polyurethane adhesive, comprising component A and component B; in parts by mass, wherein:

[0061] The raw material composition of component A includes: 50 parts of isocyanate prepolymer, 5 parts of amino-modified nano-silicon nitride, 3 parts of cationic cellulose nanofibers, and 10 parts of benzyl alcohol diluent;

[0062] The raw material composition of component B includes: 50 parts of polyester polyol, 5 parts of chain extender, 0.5 parts of catalyst and 2 parts of antioxidant.

[0063] The preparation steps of component A include: mixing the isocyanate prepolymer and the benzyl alcohol diluent at 40° C. and 400 rpm for 20 minutes; adding the amino-modified nano silicon nitride and the cationic cellulose nanofibers in three batches, with an interval of 5 minutes between each batch, using a three-roll mill for three cycles, and packaging them independently;

[0064] The preparation steps of component B include: mixing polyester polyol, chain extender, catalyst and antioxidant, and then independently packing after ultrasonic dispersion.

[0065] Comparative Example 2

[0066] A two-component polyurethane adhesive, comprising component A and component B; in parts by mass, wherein:

[0067] The raw material composition of component A includes: 50 parts of isocyanate prepolymer, 5 parts of silanized glass fiber whiskers, 3 parts of cationic cellulose nanofibers, and 10 parts of benzyl alcohol diluent;

[0068] The raw material composition of component B includes: 50 parts of polyester polyol, 5 parts of chain extender, 0.5 parts of catalyst and 2 parts of antioxidant.

[0069] The preparation steps of component A include: mixing the isocyanate prepolymer and the benzyl alcohol diluent at 40°C at 400 rpm for 20 minutes; adding silanized glass fiber shreds and treating them with a high-speed disperser at 2000 rpm for 30 minutes; adding cationic cellulose nanofibers in three batches, with an interval of 5 minutes between each batch, using a three-roll grinder, repeating three times, and packaging them independently;

[0070] The preparation steps of component B include: mixing polyester polyol, chain extender, catalyst and antioxidant, and then independently packing after ultrasonic dispersion.

[0071] Comparative Example 3

[0072] A two-component polyurethane adhesive, comprising component A and component B; in parts by mass, wherein:

[0073] The raw materials of component A include: 50 parts of isocyanate prepolymer, 5 parts of silanized glass fiber whiskers, 5 parts of amino-treated nano silicon nitride, and 10 parts of benzyl alcohol diluent;

[0074] The raw material composition of component B includes: 50 parts of polyester polyol, 5 parts of chain extender, 0.5 parts of catalyst and 2 parts of antioxidant.

[0075] The preparation steps of component A include: mixing the isocyanate prepolymer and the benzyl alcohol diluent at 40°C at 400 rpm for 20 minutes; adding silanized glass fiber whiskers and treating them with a high-speed disperser at 2000 rpm for 30 minutes; adding amino-treated nano silicon nitride in three batches, with an interval of 5 minutes between each batch, using a three-roll grinder, repeating three times, and packaging them independently;

[0076] The preparation steps of component B include: mixing polyester polyol, chain extender, catalyst and antioxidant, and then independently packing after ultrasonic dispersion.

[0077] The two-component polyurethane adhesives obtained in the above Examples 1-3 and Comparative Examples 1-3 were tested.

[0078] Tensile shear strength test: refer to GB / T7124-2008;

[0079] Fracture energy: refer to ISO 25217:2009;

[0080] The test results are as follows:

[0081] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Tensile shear strength (MPa) 13.7 14.5 14.4 4.1 10.3 8.7 Fracture energy (J / m²) 2271 2246 2253 866 1742 957

[0082] According to the above test results, the tensile shear strength of Examples 1-3 is above 13.7MPa, and the fracture energy is above 2200J / m², which is much greater than the experimental results of Comparative Examples 1-3. The components of Comparative Example 1 lack silanized glass fiber whiskers, and it is speculated that the lack of a rigid skeleton causes the tensile shear strength and fracture energy to be much lower than the data of other experimental groups; the components of Comparative Example 2 lack amino-type nano-silicon nitride, which also causes its tensile shear strength and fracture energy to be lower than Examples 1-3, but its performance is better than that of Comparative Example 1. It is speculated that this is because the cross-scale interpenetrating structure formed by glass fiber (micrometer level) and CNF (nanoscale) still plays a role in improving the tensile shear strength; the components of Comparative Example 3 lack cationized cellulose nanofibers, and its test results are better than those of Comparative Example 1, but worse than those of Comparative Example 2. It is speculated that the nano-scale CNF-Si 3 N 4 The Internet still plays a huge role.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A two-component polyurethane adhesive, characterized in that: It includes component A and component B; Calculated by mass, where: The raw material composition of component A includes: 50-60 parts of isocyanate prepolymer, 5-7 parts of silanized glass fiber whiskers, 3-5 parts of amino-treated nano silicon nitride, 2-3 parts of cationic cellulose nanofibers, and 8-10 parts of benzyl alcohol diluent; the length of the cationic cellulose nanofibers is 200-800nm; the length of the silanized glass fiber whiskers is 50-80μm; The raw material composition of component B includes: 50-60 parts of polyester polyol, 5-10 parts of chain extender, 0.1-0.5 parts of catalyst and 0.5-2 parts of antioxidant.

2. The two-component polyurethane adhesive according to claim 1, characterized in that: The isocyanate prepolymer is selected from toluene diisocyanate prepolymer, isophorone diisocyanate prepolymer, diphenylmethane diisocyanate prepolymer or lysine diisocyanate prepolymer.

3. The two-component polyurethane adhesive according to claim 1, characterized in that: The polyester polyol is polycarbonate diol.

4. The two-component polyurethane adhesive according to claim 1, characterized in that: The chain extender is selected from 1,4-butanediol or glycerol.

5. The two-component polyurethane adhesive according to claim 1, characterized in that: The catalyst is selected from dibutyltin diacetate or dibutyltin dilaurate.

6. The two-component polyurethane adhesive according to claim 1, characterized in that: When in use, component A and component B are mixed in a mass ratio of 1:1; curing conditions: cure at room temperature for 10-12 hours, then heat to 80-85°C for 1-2 hours.

7. A process for preparing a two-component polyurethane adhesive as claimed in any one of claims 1 to 6, characterized in that: in: The preparation steps of component A include: mixing isocyanate prepolymer and benzyl alcohol diluent at 40° C. at 400-500 rpm for 15-20 minutes; adding silanized glass fiber shreds and treating them with a high-speed disperser at 2000-2500 rpm for 20-30 minutes; adding amino-modified nano silicon nitride and cationic cellulose nanofibers in three batches, with an interval of 5-6 minutes between each batch, treating them with a three-roll mill, repeating three times, and packaging them independently; The preparation steps of component B include: mixing polyester polyol, chain extender, catalyst and antioxidant, and then independently packing after ultrasonic dispersion.

8. The preparation process according to claim 7, characterized in that: The treatment method of silanized glass fiber whiskers is as follows: immerse the glass fiber whiskers in 5% KH-550 ethanol solution, the mass ratio of ethanol to water is 9:1, pH=4.5, reflux reaction at 80℃ for 3h, and centrifugal drying; The treatment method of amino-treated nano silicon nitride is as follows: disperse nano silicon nitride in toluene, control the solid content to 8%-10%, add 3-aminopropyltriethoxysilane, the mass ratio of nano silicon nitride to 3-aminopropyltriethoxysilane is 1:0.2, react under nitrogen protection at 110°C for 6 hours, centrifuge, wash and dry; The treatment method of cationic cellulose nanofibers is as follows: disperse the cellulose nanofibers in deionized water at a mass ratio of 1:20, add 2,3-epoxypropyltrimethylammonium chloride, the mass ratio of cellulose nanofibers to 2,3-epoxypropyltrimethylammonium chloride is 1:0.9, adjust the pH to 5 with acetic acid, react at 60°C for 12 hours, dialysis purification, and freeze-drying.