An aqueous adhesive with a matte finish and its preparation method

Abstract

The present invention relates to an aqueous adhesive with a matte and foggy effect and a preparation method thereof, belonging to the technical field of aqueous adhesives. Creatively, 2-aminoterephthalic acid and ferric chloride hexahydrate are used as an organic ligand and an iron source respectively to construct a metal-organic framework containing amino groups. Then, hollow silica is synthesized based on a method and its surface is modified with an amino coupling agent to prepare hollow silica containing amino groups. Next, a compound with an epoxy group at the end and a methyl group on the side chain, obtained by hydrosilylation of tetramethyldisiloxane and 3,4-epoxy-1-butene, is used as a crosslinking agent to carry out ring-opening bonding between the epoxy group and the amino group, realizing the crosslinking and compounding of the metal-organic framework and the hollow silica, thereby obtaining a modified matting agent. After physically blending it with an aqueous polyurethane dispersion and an antifoaming agent, an aqueous adhesive with a matte and foggy effect is prepared.

Description

Technical Field

[0001] The invention belongs to the technical field of water-based adhesives, and particularly relates to a water-based adhesive with a matte surface effect and a preparation method thereof. Background Art

[0002] Water-based adhesives refer to a type of adhesive material that uses water as a solvent or dispersion medium. They are generally composed of water-based resin dispersions, additives, etc. If classified according to the type of water-based resin dispersion, water-based adhesives can be roughly divided into water-based acrylic adhesives, water-based polyurethane adhesives, water-based epoxy resin adhesives, etc. Among them, water-based polyurethane adhesives are widely used in the fields of footwear, furniture manufacturing, fabrics, etc. due to their many advantages such as being green, environmentally friendly, and highly applicable. However, the existing water-based polyurethane adhesives still have certain disadvantages that limit their actual application effectiveness. This is because most of the existing water-based polyurethane adhesives do not have a matte matte effect (the so-called matte matte refers to the low surface gloss of the adhesive layer of the water-based polyurethane adhesive after curing, which can present a soft and hazy visual experience), which makes it difficult to glue some items that already have a matte matte effect, which can easily cause "reflection" at the glued area after gluing, resulting in a sense of abruptness and is not conducive to overall beauty. Summary of the invention

[0003] In view of the problems existing in the prior art, the purpose of the present invention is to provide a water-based adhesive with a matte effect and a preparation method thereof. The present invention creatively uses 2-aminoterephthalic acid and ferric chloride hexahydrate as organic ligands and iron sources, respectively, to construct a metal organic framework containing amino groups, and then Hollow silica is synthesized by a method and surface modified with an amino coupling agent to prepare hollow silica containing an amino group. Subsequently, a compound with an epoxy terminal group and a methyl side group obtained by hydrosilylation of tetramethyldisiloxane and 3,4-epoxy-1-butene is used as a cross-linking agent to cause ring-opening bonding between the epoxy group and the amino group to achieve cross-linking and compounding of the metal organic framework and the hollow silica, thereby obtaining a modified matting agent, which is physically blended with an aqueous polyurethane dispersion and a defoaming agent to prepare a water-based adhesive having a matte effect.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A water-based adhesive with a matte effect is prepared from a water-based polyurethane dispersion, a defoaming agent and a modified matting agent.

[0006] As a preferred technical solution of the present invention, the mass ratio of the aqueous polyurethane dispersion, the defoaming agent and the modified matting agent is 100:0.1-0.3:1-2.

[0007] As a preferred technical solution of the present invention, the aqueous polyurethane dispersion is obtained by directly purchasing from the market.

[0008] As a preferred technical solution of the present invention, the defoaming agent is obtained by directly purchasing from the market.

[0009] As a preferred technical solution of the present invention, the modified matting agent is prepared by the following steps:

[0010] Step A: Mix 2-aminoterephthalic acid, ferric chloride hexahydrate and N,N-dimethylformamide in a mass ratio of 1-2:3-4:90-100, stir at room temperature for 30-60 min, then carry out hydrothermal reaction at 120-140 °C for 24 h, naturally cool to room temperature, filter by suction, take the filter residue, wash with methanol, and finally carry out vacuum drying at 60-80 °C until constant weight to obtain Component A;

[0011] Step B: Add 1 part by weight of hollow silica, 0.2-0.25 part by weight of amino coupling agent and 0.1 part by weight of deionized water to 100 parts by weight of absolute ethanol, then stir and mix at 60-70 °C for 6-8 h, filter by suction, take the filter residue, wash with deionized water, and finally carry out vacuum drying at 60-80 °C until constant weight to obtain Component B;

[0012] Step C: Mix tetramethyldisiloxane, 3,4-epoxy-1-butene and platinum catalyst in a mass ratio of 1:5-6:0.3-0.5, stir at 45-50 °C for 6 h, filter by suction, remove the filter residue, and distill to obtain Component C;

[0013] Step D: Add 0.5-0.7 part by weight of Component A, 1 part by weight of Component B and 0.2 part by weight of Component C to 100 parts by weight of dimethyl sulfoxide, then stir and mix at 70-80 °C for 24 h, filter by suction, take the filter residue, wash with deionized water, and finally carry out vacuum drying at 60-80 °C until constant weight, thus completing the preparation.

[0014] Furthermore, the hollow silica in Step B is prepared by the following steps:

[0015] Add 80 parts by weight of absolute ethanol and 1-1.5 parts by weight of polyacrylic acid to 20-30 parts by weight of ammonia water with a mass fraction of 25-30%, then stir and mix at room temperature for 10-15 min, then dropwise add 10-12 parts by weight of tetraethyl orthosilicate dropwise while stirring, continue to stir for 4-6 h after the addition is completed, filter by suction, take the filter residue, wash with deionized water, and finally carry out vacuum drying at 60-80 °C until constant weight, thus completing the preparation.

[0016] Preferably, the molecular weight of the polyacrylic acid is 5000.

[0017] Preferably, the dropping rate is controlled at 3 - 4 s / drop.

[0018] Further, the amino coupling agent in step B is silane coupling agent KH - 540.

[0019] Further, the platinum catalyst in step C is obtained by directly purchasing from the market.

[0020] Further, the distillation in step C means distilling for 1 h at 65 - 68 °C to remove volatiles.

[0021] A preparation method of a water - based adhesive with a matte and foggy effect, the preparation method comprising the following steps:

[0022] Mix the water - based polyurethane dispersion, defoamer and modified matting agent at room temperature with a stirring speed of 800 - 1000 rpm for 5 - 10 min to complete the preparation.

[0023] A using method of a water - based adhesive with a matte and foggy effect, the using method comprising the following steps:

[0024] Coat the water - based adhesive on the surface of the substrate, then laminate, then cure at 50 - 60 °C for 4 - 6 h, and finally leave it to stand naturally at room temperature for 4 - 5 days.

[0025] Advantages of the present invention:

[0026] (1) Creatively, the present invention uses 2 - aminoterephthalic acid and ferric chloride hexahydrate as an organic ligand and an iron source respectively to construct a metal - organic framework containing amino groups, and then based on the method to synthesize hollow silica and perform surface modification with an amino coupling agent on it, preparing hollow silica containing amino groups. Then, using the compound with an epoxy group at the end and methyl groups on the side chain obtained by hydrosilylation of tetramethyldisiloxane and 3,4 - epoxy - 1 - butene as a cross - linker, ring - opening bonding of the epoxy group and the amino group occurs to achieve cross - linking and compounding of the metal - organic framework and hollow silica, thereby obtaining a modified matting agent. After physically blending it with the water - based polyurethane dispersion and defoamer, a water - based adhesive is prepared, which has a matte and foggy effect.

[0027] (2) The present invention creatively prepares a modified matting agent, which endows the water-based adhesive with a matte and foggy effect. Compared with the prior art that directly uses spherical silica as the matting agent, the modified matting agent of the present invention can obtain a rougher surface structure by virtue of the polyhedral metal-organic framework, and correspondingly, the matte and foggy effect is better. At the same time, since a cross-linking agent with a methyl side group is used to cross-link and compound the metal-organic framework and hollow silica (the present invention synthesizes hollow silica based on the Stöber method. First, polyacrylic acid is dissolved in a mixed system of ammonia water / absolute ethanol to form a colloidal aggregate, and then the tetraethyl orthosilicate dropped in undergoes hydrolysis on the surface of the colloidal aggregate to generate silica. Subsequently, after washing to remove the internal colloidal aggregate and drying, it is obtained), the surface energy of the prepared modified matting agent is low, and to a certain extent, it can migrate spontaneously to the surface layer during the curing process of the water-based adhesive by utilizing the difference in surface tension, and then better form a rough surface structure. In addition, the hollow silica also greatly reduces the resistance during migration. Finally, through the synergistic effect of multiple aspects, the cured adhesive layer has an excellent matte and foggy effect.

[0028] (3) Starting from the principle of matte and foggy, the cured adhesive layer of the prepared water-based adhesive of the present invention has a higher surface roughness and better unevenness, and an excellent matte and foggy effect can be obtained by adding a small amount of the modified matting agent. Detailed implementation mode

[0029] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following combines examples to describe in detail the specific implementation mode, structure, characteristics and effects according to the present invention.

[0030] The sources of the raw materials are as follows: The water-based polyurethane dispersion is purchased from Anhui Dawei Huatai New Materials Technology Co., Ltd., and the product name is cationic water-based polyurethane dispersion AH-0201C, and the solid content (%) is 45 ± 1%; the defoamer is purchased from BYK of Germany, and the model is BYK-025 defoamer; the platinum catalyst is purchased from Shaanxi Ruike New Materials Co., Ltd., and the product name is platinum-carbon.

[0031] Example 1

[0032] A water-based adhesive with a matte and foggy effect, which is prepared from a water-based polyurethane dispersion, a defoamer and a modified matting agent.

[0033] The mass ratio of the water-based polyurethane dispersion, the defoamer and the modified matting agent is 100:0.1:1.

[0034] The modified matting agent is prepared by the following steps:

[0035] Step A: Mix 2-aminoterephthalic acid, ferric chloride hexahydrate, and N,N-dimethylformamide at a mass ratio of 1:3:90 by stirring at room temperature for 30 min. Then, perform a hydrothermal reaction at 120 °C for 24 h, cool naturally to room temperature, perform suction filtration, take the filter residue, wash it with methanol, and finally dry it under vacuum at 60 °C until constant weight to obtain Component A;

[0036] Step B: Add 1 part by weight of hollow silica, 0.2 part by weight of an amino coupling agent, and 0.1 part by weight of deionized water to 100 parts by weight of absolute ethanol. Then, stir and mix at 60 °C for 6 h, perform suction filtration, take the filter residue, wash it with deionized water, and finally dry it under vacuum at 60 °C until constant weight to obtain Component B;

[0037] Step C: Mix tetramethyldisiloxane, 3,4-epoxy-1-butene, and a platinum catalyst at a mass ratio of 1:5:0.3 by stirring at 45 °C for 6 h. Perform suction filtration, remove the filter residue, and distill to obtain Component C;

[0038] Step D: Add 0.5 part by weight of Component A, 1 part by weight of Component B, and 0.2 part by weight of Component C to 100 parts by weight of dimethyl sulfoxide. Then, stir and mix at 70 °C for 24 h, perform suction filtration, take the filter residue, wash it with deionized water, and finally dry it under vacuum at 60 °C until constant weight to complete the preparation.

[0039] The hollow silica described in Step B is prepared through the following steps:

[0040] Add 80 parts by weight of absolute ethanol and 1 part by weight of polyacrylic acid to 20 parts by weight of 25% ammonia water. Then, stir and mix at room temperature for 10 min. Next, while stirring, dropwise add 10 parts by weight of tetraethyl orthosilicate. After the addition is complete, continue stirring for 4 h. Perform suction filtration, take the filter residue, wash it with deionized water, and finally dry it under vacuum at 60 °C until constant weight to complete the preparation.

[0041] The molecular weight of the polyacrylic acid is 5000.

[0042] The dropping rate is controlled at 3 s / drop.

[0043] The amino coupling agent described in Step B is the silane coupling agent KH-540.

[0044] The distillation described in Step C means distilling at 65 °C for 1 h to remove volatiles.

[0045] A preparation method of a water-based adhesive with a matte and foggy effect, the preparation method comprising the following steps:

[0046] Mix an aqueous polyurethane dispersion, an antifoaming agent, and a modified matting agent by stirring at a stirring speed of 800 rpm at room temperature for 5 min to complete the preparation.

[0047] Example 2

[0048] An aqueous adhesive with a matte finish, which is prepared from an aqueous polyurethane dispersion, an antifoaming agent, and a modified matting agent.

[0049] The mass ratio of the aqueous polyurethane dispersion, the antifoaming agent, and the modified matting agent is 100:0.3:2.

[0050] The modified matting agent is prepared through the following steps:

[0051] Step A: Mix 2-aminoterephthalic acid, ferric chloride hexahydrate, and N,N-dimethylformamide in a mass ratio of 2:4:100, stir at room temperature for 60 min, then carry out hydrothermal reaction at 140 °C for 24 h, naturally cool to room temperature, carry out suction filtration, take the filter residue, wash it with methanol, and finally carry out vacuum drying at 80 °C until constant weight to obtain Component A;

[0052] Step B: Add 1 part by weight of hollow silica, 0.25 part by weight of amino coupling agent, and 0.1 part by weight of deionized water to 100 parts by weight of absolute ethanol, then stir and mix at 70 °C for 8 h, carry out suction filtration, take the filter residue, wash it with deionized water, and finally carry out vacuum drying at 80 °C until constant weight to obtain Component B;

[0053] Step C: Mix tetramethyldisiloxane, 3,4-epoxy-1-butene, and platinum catalyst in a mass ratio of 1:6:0.5, stir at 50 °C for 6 h, carry out suction filtration, remove the filter residue, and distill to obtain Component C;

[0054] Step D: Add 0.7 part by weight of Component A, 1 part by weight of Component B, and 0.2 part by weight of Component C to 100 parts by weight of dimethyl sulfoxide, then stir and mix at 80 °C for 24 h, carry out suction filtration, take the filter residue, wash it with deionized water, and finally carry out vacuum drying at 80 °C until constant weight, thus completing the preparation.

[0055] The hollow silica in Step B is prepared through the following steps:

[0056] Add 80 parts by weight of absolute ethanol and 1.5 parts by weight of polyacrylic acid to 30 parts by weight of ammonia water with a mass fraction of 30%, then stir and mix at room temperature for 15 min, then dropwise add 12 parts by weight of tetraethyl orthosilicate while stirring. After the dropping is completed, continue to stir for 6 h, carry out suction filtration, take the filter residue, wash it with deionized water, and finally carry out vacuum drying at 80 °C until constant weight, thus completing the preparation.

[0057] The molecular weight of the polyacrylic acid is 5000.

[0058] The dropping rate is controlled at 4 s / drop.

[0059] The amino coupling agent described in step B is silane coupling agent KH-540.

[0060] The distillation described in step C means distilling for 1 h at 68 °C to remove volatiles.

[0061] A preparation method of a water-based adhesive with a matte finish, the preparation method comprising the following steps:

[0062] The water-based polyurethane dispersion, the defoaming agent and the modified matting agent are stirred and mixed at a stirring speed of 1000 rpm at room temperature for 10 min to complete the preparation.

[0063] Example 3

[0064] A water-based adhesive with a matte finish, the water-based adhesive being prepared from a water-based polyurethane dispersion, a defoaming agent and a modified matting agent.

[0065] The mass ratio of the water-based polyurethane dispersion, the defoaming agent and the modified matting agent is 100:0.2:1.8.

[0066] The modified matting agent is prepared by the following steps:

[0067] Step A: 2-aminoterephthalic acid, ferric chloride hexahydrate and N,N-dimethylformamide are stirred and mixed at a mass ratio of 1.5:3.5:95 at room temperature for 45 min, then hydrothermally reacted at 130 °C for 24 h, naturally cooled to room temperature, filtered, the filter cake is taken, washed with methanol, and finally vacuum dried at 70 °C until constant weight to obtain component A;

[0068] Step B: 1 part by weight of hollow silica, 0.23 part by weight of amino coupling agent and 0.1 part by weight of deionized water are added to 100 parts by weight of absolute ethanol, then stirred and mixed at 65 °C for 7 h, filtered, the filter cake is taken, washed with deionized water, and finally vacuum dried at 70 °C until constant weight to obtain component B;

[0069] Step C: Tetramethyldisiloxane, 3,4-epoxy-1-butene and platinum catalyst are stirred and mixed at a mass ratio of 1:5.5:0.4 at 48 °C for 6 h, filtered, the filter cake is removed, distilled, to obtain component C;

[0070] Step D: 0.6 part by weight of component A, 1 part by weight of component B and 0.2 part by weight of component C are added to 100 parts by weight of dimethyl sulfoxide, then stirred and mixed at 75 °C for 24 h, filtered, the filter cake is taken, washed with deionized water, and finally vacuum dried at 70 °C until constant weight to complete the preparation.

[0071] The hollow silica described in step B is prepared through the following steps:

[0072] Add 80 parts by weight of absolute ethanol and 1.3 parts by weight of polyacrylic acid to 25 parts by weight of ammonia water with a mass fraction of 27%, then stir and mix at room temperature for 13 min. Next, while stirring, dropwise add 11 parts by weight of tetraethyl orthosilicate. After the addition is complete, continue stirring for 5 h, perform suction filtration, take the filter residue, wash it with deionized water, and finally dry it under vacuum at 70 °C until constant weight, thus completing the preparation.

[0073] The molecular weight of the polyacrylic acid is 5000.

[0074] The dropping rate is controlled at 3.5 s / drop.

[0075] The amino coupling agent described in step B is silane coupling agent KH-540.

[0076] The distillation described in step C means distilling for 1 h at 66 °C to remove volatiles.

[0077] A preparation method of a water-based adhesive with a matte finish, the preparation method includes the following steps:

[0078] Stir and mix the water-based polyurethane dispersion, defoamer, and modified matting agent at a stirring speed of 900 rpm at room temperature for 8 min, thus completing the preparation.

[0079] Comparative Example 1

[0080] Based on Example 3, the modified matting agent is changed to an equal weight of component A, and the rest remains unchanged.

[0081] Comparative Example 2

[0082] Based on Example 3, the modified matting agent is changed to an equal weight of component B, and the rest remains unchanged.

[0083] Comparative Example 3

[0084] Based on Example 3, in step D, component C is changed to an equal weight of dimethyl sulfoxide, and the rest remains unchanged.

[0085] Comparative Example 4

[0086] Based on Example 3, in step D, component C is changed to an equal weight of 2,2'-hexane-1,6-diyl bis(oxirane), and the rest remains unchanged.

[0087] Comparative Example 5

[0088] On the basis of Example 3, in step B, the hollow silica is changed to solid silica (purchased from Nanjing Jike Biotechnology Co., Ltd., product name: silica microspheres, product number: JK-04-001-060), and the rest remains unchanged.

[0089] Test Example 1

[0090] Glossiness test:

[0091] The water-based adhesives prepared in Example 3 and Comparative Examples 1-5 were respectively coated on the surface of black glass, then cured at 60 °C for 4 h, and finally left to stand naturally at room temperature for 5 days to form adhesive layers with a thickness of 50 microns. The glossiness of 5 points on the adhesive layer was randomly measured at 60° using a glossiness meter, and the average value was taken.

[0092] Table 1. Glossiness test results

[0093] Glossiness / % Example 3 3.1 Comparative Example 1 10.4 Comparative Example 2 9.6 Comparative Example 3 8.2 Comparative Example 4 4.9 Comparative Example 5 6.0

[0094] From Test Example 1, by comparing Example 3 with Comparative Examples 1-5, it can be seen that the water-based adhesive prepared by the present invention has a lower glossiness after curing, and correspondingly, the matte and foggy surface effect is also better.

[0095] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed as above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to obtain equivalent embodiments with equivalent changes, but as long as the technical content of the present invention is not departed from, any brief modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A water-based adhesive with a matte effect, characterized in that: The water-based adhesive is prepared from a water-based polyurethane dispersion, a defoamer and a modified matting agent; The modified matting agent is prepared by the following steps: Step A: 2-aminoterephthalic acid, ferric chloride hexahydrate and N,N-dimethylformamide are mixed at a mass ratio of 1-2:3-4:90-100 at room temperature with stirring for 30-60 minutes, and then hydrothermally reacted at 120-140° C. for 24 hours, naturally cooled to room temperature, filtered, and the filter residue is taken, washed with methanol, and finally vacuum dried at 60-80° C. until constant weight, to obtain component A; Step B: adding 1 part by weight of hollow silica, 0.2-0.25 parts by weight of an amino coupling agent and 0.1 parts by weight of deionized water to 100 parts by weight of anhydrous ethanol, stirring and mixing at 60-70° C. for 6-8 hours, filtering, taking the filter residue, washing with deionized water, and finally vacuum drying at 60-80° C. until constant weight, to obtain component B; Step C: tetramethyldisiloxane, 3,4-epoxy-1-butene and platinum catalyst are mixed at a mass ratio of 1:5-6:0.3-0.5 at 45-50° C. for 6 hours, filtered, the residue is removed, and distilled to obtain component C; Step D: Add 0.5-0.7 parts by weight of component A, 1 part by weight of component B and 0.2 parts by weight of component C to 100 parts by weight of dimethyl sulfoxide, and then stir and mix at 70-80° C. for 24 hours, filter, take the filter residue, wash with deionized water, and finally vacuum dry at 60-80° C. until constant weight, and the preparation is completed; The hollow silica in step B is prepared by the following steps: adding 80 parts by weight of anhydrous ethanol and 1-1.5 parts by weight of polyacrylic acid to 20-30 parts by weight of ammonia water with a mass fraction of 25-30%, and then stirring for 10-15 minutes at room temperature, and then adding 10-12 parts by weight of ethyl orthosilicate dropwise while stirring, and continuing to stir for 4-6 hours after the addition is completed, filtering, taking the filter residue, washing with deionized water, and finally vacuum drying at 60-80°C until constant weight, that is, the preparation is completed.

2. The water-based adhesive with a matte effect according to claim 1, characterized in that: The mass ratio of the aqueous polyurethane dispersion, the defoaming agent and the modified matting agent is 100:0.1-0.3:1-2.

3. The water-based adhesive with a matte effect according to claim 1, characterized in that: The molecular weight of the polyacrylic acid is 5,000.

4. The water-based adhesive with a matte effect according to claim 1, characterized in that: The dropping rate is controlled at 3-4s / drop.

5. The water-based adhesive with a matte effect according to claim 1, characterized in that: The amino coupling agent in step B is silane coupling agent KH-540.

6. The water-based adhesive with a matte effect according to claim 1, characterized in that: The distillation in step C refers to distilling at 65-68° C. for 1 h to remove volatiles.

7. A method for preparing a water-based adhesive with a matte effect as claimed in any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: The preparation is completed by stirring the aqueous polyurethane dispersion, the defoaming agent and the modified matting agent at a stirring speed of 800-1000 rpm for 5-10 minutes.

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