Single-component functional polyurethane adhesive, bonding piece as well as preparation and application of single-component functional polyurethane adhesive and bonding piece

Abstract

The invention relates to a single-component functional polyurethane adhesive, a bonding piece and preparation and application of the single-component functional polyurethane adhesive. The single-component functional polyurethane adhesive comprises isocyanate, macromolecular polyol, a chain extender and a curing agent. According to the single-component functional polyurethane adhesive provided by the invention, a solvent and a catalyst are not required to be used in the production process, the pollution to the environment is greatly reduced, a strong bonding effect is realized by utilizing rapid reversible recombination of dynamic chemical bonds and efficient infiltration and permeation of a bonding material, and a reversible Diels-Alder reaction contained in the structure can be used for preparing the single-component functional polyurethane adhesive. Therefore, the adhesive can be detached and reused as required under the condition of thermal stimulation. Glue can be applied in a hot pressing mode, a glue film mode, a glue gun mode or a glue dispensing mode according to the actual situation, and the industrial application prospect is extremely high.

Description

Technical Field

[0001] The invention belongs to the field of adhesive materials, and in particular relates to a one-component functional polyurethane adhesive, a bonding piece, and preparation and application thereof. Background Art

[0002] Any polyurethane adhesive product involves a process of production, preparation, use, and disposal. During the production process, the viscosity of the reaction liquid increases continuously, so high-boiling-point solvents are used to reduce the viscosity. However, there is a risk of environmental pollution caused by solvent volatilization during use.

[0003] Secondly, single-component polyurethane adhesives generally come in two types: one is a fast-curing type containing a linear structure that relies on non-covalent interactions, but due to its low bonding strength, its use scenarios are greatly limited; the other is a slow-curing type containing a micro-crosslinked structure that relies on the formation of a permanent crosslinked structure. It usually has high bonding strength, but a long curing time, making it unsuitable for scenarios requiring fast curing, such as fabric bonding. Once cured, it is difficult to disassemble and can only be completely discarded after the service life. This greatly limits the use scenarios that require disassembly and recycling of adhesive components, and also results in a waste of resources. Emerging reversible adhesives are gradually coming into the user's perspective. The dynamic chemical bonds contained in the adhesive structure give the bonding reversibility, that is, after bonding, the bonding area can be stimulated to complete debonding as needed. However, this type of adhesive still faces the following key challenges in the preparation and use process: 1. The use of solvents in the preparation process will cause environmental pollution, and the subsequent solvent removal process will increase production costs; 2. The bonding strength is usually not high, with an initial bonding strength of less than 5MPa and a final bonding strength of less than 10MPa, which cannot cover most usage scenarios; 3. The bonding force is weak for difficult-to-bond materials such as nylon, and the peel force is less than 5N / 25mm; 4. Adhesives with high bonding strength have high viscosity and poor leveling during use. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a one-component functional polyurethane adhesive, a bonding piece and the preparation and application thereof.

[0005] The present invention provides a polyurethane adhesive, which comprises the following components in parts by mass:

[0006]

[0007] Preferably, the isocyanate is a polyisocyanate; wherein the polyisocyanate structure contains at least two terminal isocyanate groups.

[0008] Furthermore, the polyisocyanate is an aromatic polyisocyanate or an aliphatic polyisocyanate;

[0009] More preferably, the polyisocyanate includes one or more of 4,4'-methylenebis(phenyl isocyanate), toluene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane-diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, 1,4-cyclohexane diisocyanate, xylylene diisocyanate, cyclohexane dimethylene diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, tetramethyl-m-xylylene diisocyanate, norbornane diisocyanate, dimethyl diphenyl diisocyanate, methylcyclohexyl diisocyanate, polymethylene polyphenyl isocyanate, 1,6-hexamethylene diisocyanate, modified diisocyanate (such as Yantai Wanhua's liquefied MDI), 1,5-pentane diisocyanate, and 2,5-furan diisocyanate.

[0010] Preferably, the relative molecular weight of the macromolecular polyol is 600-4000; the polyol is one or more alcohol substances containing ester groups (-COO-) and / or ether bonds (-O-) on the main chain of the molecule and hydroxyl groups (-OH) at the end groups; the alcohol substance can be a compound, a polymer or an oligomer.

[0011] Furthermore, the macromolecular polyol is one or more of polyether polyol and polyester polyol.

[0012] More preferably, the polyether polyol is selected from at least one of polyoxypropylene diol, polyoxypropylene triol, polyoxypropylene-ethylene oxide diol, polyoxypropylene-ethylene oxide triol, polytetrahydrofuran diol and polytetrahydrofuran triol; and the molecular weight of the polyether polyol is 600-4000.

[0013] More preferably, the polyester polyol is selected from at least one of polyethylene adipate diol, polybutylene adipate diol, polyhexane adipate diol, polycarbonate diol, polyphthalate diol, polyneopentyl adipate diol, polycaprolactone diol, polyethylene adipate monopropylene glycol ester diol, polyethylene adipate diacetal diol, polyethylene adipate diacetal diol, and bio-based polyester polyol.

[0014] Furthermore, more preferably, the bio-based polyester polyol is produced by reacting a bio-based dibasic acid and a diol. The bio-based dibasic acid includes adipic acid, sebacic acid, succinic acid, citric acid, 2,5-furandicarboxylic acid, and tetrahydrofuran-2,5-dicarboxylic acid. The bio-based diol includes ethylene glycol, 1,3-propylene glycol, and 1,4-butanediol. The molecular weight of the polyester polyol is 600-4000.

[0015] Preferably, the curing agent includes one or more of a trimer formed by isocyanate and a triisocyanate.

[0016] The trimer formed by the isocyanate includes one or more of hexamethylene diisocyanate trimer, isophorone diisocyanate trimer, diphenylmethane diisocyanate trimer, toluene diisocyanate trimer, and pentamethylene diisocyanate trimer; the triisocyanate includes one or more of triphenylmethane triisocyanate, tris(isocyanate phenyl)thiophosphate, and 1,6,10-undecane triisocyanate.

[0017] Preferably, the raw material components of the chain extender include alcohols and / or amines, and compounds containing maleimide functional groups.

[0018] Furthermore, the chain extender is obtained by reacting raw materials containing alcohol and / or amine and a compound containing a maleimide functional group; wherein the reaction is carried out at 60-100° C. for 0.5-4 h under an inert protective gas.

[0019] The inert protective gas includes nitrogen or argon.

[0020] Furthermore, the alcohol is an alcohol containing a furan ring group; the amine is a diamine containing a furan ring group; the compound having a maleimide functional group is one or more of N,N'-(4,4'-methylenediphenyl)bismaleimide and m-phenylenebismaleimide;

[0021] The alcohol is a monohydric alcohol or a dihydric alcohol, and the general structural formula of the dihydric alcohol includes HO-R-OH (R is a group with a furan ring) and HS-R-SH (R is a group with a furan ring);

[0022] Furthermore, the special monohydric alcohol is furfuryl alcohol, and the dihydric alcohol includes one or more of 2,5-furan dimethanol and furfuryl mercaptan.

[0023] The general structural formula of the diamine includes R1-R-NH2 (R is a furan ring, R1 is an arbitrary group), R1-NH-R-NH-R2 (R is a group with a furan ring, R1 and R2 are arbitrary groups).

[0024] The molar ratio of the alcohol and / or amine to the compound containing maleimide functional group in the chain extender is 0.1-2:1.

[0025] The functional chain extender in the present invention is a compound having a terminal group carrying a diol or a diamine and containing a Diels-Alder reaction (DA reaction for short), and is formed by a reaction under the solubilization conditions of a heated macromolecular polyol.

[0026] Further preferably, the components in parts by mass include:

[0027]

[0028] The present invention provides a method for preparing the polyurethane adhesive, comprising:

[0029] The components are weighed according to mass fractions, and the synthetic raw materials of the macromolecular polyol and the chain extender are mixed, reacted under an inert protective gas, and then isocyanate is added to react, and then a curing agent is added to continue the reaction to obtain a polyurethane adhesive.

[0030] The macromolecular polyol is a pretreated macromolecular polyol; further, the pretreatment (dehydration treatment) includes: dehydrating the polyol under vacuum stirring at 110-120° C. for 1-3 hours, and then cooling to obtain the pretreated polyol.

[0031] The maleimide functional compound reacts with the special alcohol and / or amine for 0.5-4 hours to form a functional chain extender.

[0032] The inert protective gas includes nitrogen or argon;

[0033] The reaction is carried out at 60-100° C. for 0.5-4 h under an inert protective gas;

[0034] Furthermore, the step of adding isocyanate to react and then adding a curing agent to continue the reaction comprises: adding isocyanate to react at 60-140° C. for 1-24 hours, then adding a curing agent to react at 60-140° C. for 0.05-2 hours, and further reacting the resulting reaction solution at 50-150° C. in a vacuum oven for 2-14 hours, and vacuum degassing at a pressure of 0.05-0.1 MPa for 5-10 minutes.

[0035] The present invention provides a bonding piece, which includes the polyurethane adhesive.

[0036] The bonding member also includes a substrate, wherein the matrix includes one or more of metal (stainless steel, aluminum alloy, iron, copper), plastic (epoxy resin, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyolefin, polyamide), composite material (glass fiber board, carbon fiber composite material), glass, ceramics, wood, and fabric.

[0037] The adhesive can be disassembled and / or reused as needed under the condition of thermal stimulation.

[0038] Furthermore, for example, when a bonding area of ​​a bonding part formed by hot pressing or dispensing with the functional polyurethane adhesive is damaged, the original bonding area is heated to 70-160° C. and the bonded parts are re-bonded.

[0039] Furthermore, the functional polyurethane adhesive is used as an adhesive to bond the bonded parts. When the bonding is broken and needs to be reused, the original bonding area can be reheated to 90-160°C (such as 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc.) to re-bond the bonded parts.

[0040] The present invention provides an application of the polyurethane adhesive and the adhesive member in scenarios requiring reversible disassembly and reuse, such as bonding-disassembly-recycling of electronic components, bonding-disassembly-recycling of automobile interiors, bonding-disassembly-recycling of battery modules of new energy vehicles, bonding-disassembly-recycling of nylon fabrics, etc., or repeated bonding of substrates such as metal, plastic, wood, composite materials, glass, and fabrics.

[0041] The polyurethane adhesive in the present invention is a solvent-free, catalyst-free, high-performance, easy-to-process and detachable single-component functional polyurethane adhesive.

[0042] The functional polyurethane adhesive provided by the present invention has a reversible DA reaction in its structure, which can realize the dissociation and reorganization of the adhesive structure under the condition of thermal stimulation, thereby realizing the on-demand disassembly of the adhesive ( Figure 1 ). During the production process, no solvents and catalysts are required, and the reaction can be controlled simply by adjusting the temperature. During use, fast-curing adhesives with linear structures that rely on the formation of non-covalent interactions can cure quickly, and slow-curing adhesives that can be reshaped and form permanent cross-linked structures have the characteristics of high bonding strength, excellent chemical resistance and weather resistance. On the other hand, the design of low cross-linking degree and high functional component content breaks the processing limitations of cross-linked polyurethane, making it easy to apply glue. Gluing can be selected in the form of hot pressing, film, glue gun or dispensing according to actual conditions. Finally, the adherends can be disassembled point by point according to usage requirements, achieving green and environmentally friendly control of the entire process.

[0043] To address the various problems existing in single-component polyurethane adhesives, including production (using solvents and catalysts that cause environmental pollution), use (insufficient bonding performance), and end-of-life (unreusability), the present invention provides a single-component functional polyurethane adhesive. This adhesive eliminates the need for solvents and catalysts during production, significantly reducing environmental pollution. It achieves strong bonding by utilizing the rapid, reversible recombination of dynamic chemical bonds and efficient wetting and penetration of the adhesive material. The reversible Diels-Alder reaction incorporated into its structure enables on-demand disassembly and reuse under thermal stimulation. Application of the adhesive can be selected through thermal compression, film application, glue gun application, or dispensing, depending on the specific application, demonstrating its high potential for industrial application.

[0044] In addition, the functional polyurethane adhesive prepared by the present invention does not require special production and use equipment, and can be fully covered by existing polyurethane adhesive equipment, saving additional capital and cost investment, and has extremely high industrial application prospects.

[0045] Beneficial effects

[0046] (1) The one-component functional polyurethane adhesive prepared by the present invention does not require the participation of solvents and catalysts in the entire process.

[0047] (2) The one-component functional polyurethane adhesive prepared by the present invention has an open time comparable to that of commercially available products, but has significantly better bonding performance than commercially available products and corresponding reversible polyurethane adhesives.

[0048] (3) It also has good bonding properties to difficult-to-bond materials (such as untreated polypropylene and nylon).

[0049] (4) It has good gluing performance, and the adhesive can be disassembled and recycled as needed after use. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a schematic diagram of the design principle of the one-component functional polyurethane adhesive of the present invention;

[0051] Figure 2 This is a product property diagram of the one-component functional polyurethane adhesive of the present invention;

[0052] Figure 3 A comparison chart of the mechanical properties of the one-component functional polyurethane adhesives prepared in the examples and the comparative examples;

[0053] Figure 4 (a) is a comparison diagram of the processing properties of the one-component functional polyurethane adhesives prepared in the examples and the comparative examples, and (b) is a processing diagram of CDAPU3;

[0054] Figure 5 Comparative graph of the bonding performance of the one-component functional polyurethane adhesive prepared in the embodiment and the control example to aluminum alloy (a), comparative graph of the bonding performance of CDAPU3 to metal stainless steel and aluminum alloy at different cooling and solidification times (b), comparative graph of the bonding performance of CDAPU3 to different materials (metal, plastic, wood, composite materials, etc.) (c), and graph of the repeated bonding performance of CDAPU3 to aluminum alloy (d).

[0055] Figure 6 This is a test chart of the peeling performance of CDAPU3 on nylon cloth. DETAILED DESCRIPTION

[0056] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0057] Polybutylene adipate diol (molecular weight 1000) and N,N'-(4,4'-methylenediphenyl)bismaleimide were purchased from Shanghai MacLean Biochemical Technology Co., Ltd., furfuryl alcohol and hexamethylene diisocyanate trimer were purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd., and 4,4'-methylenebis(phenyl isocyanate) was purchased from Wanhua Chemical Group Co., Ltd.

[0058] Related test content:

[0059] Characterization of the mechanical properties of the one-component functional polyurethane adhesive: The following examples and control examples use a universal material testing machine to characterize the mechanical properties of the hot melt adhesive. Dumbbell-shaped strips are cut from the prepared samples, and the mechanical properties of the materials are tested at room temperature. The uniaxial tensile rate is set to 50 mm / min.

[0060] Hot Melt Adhesive Processing Performance Characterization: The rheological properties of the cross-linked polyurethane hot melt adhesive were characterized using an Anton Paar high-temperature rotational rheometer. The temperature was ramped from 60°C to 170°C at a heating rate of 5°C / min. The strain frequency was 1 Hz, and the strain level was 1%.

[0061] Characterization of hot melt adhesive bonding performance: A micro-controlled electronic universal testing machine was used to test the bonding performance of the cross-linked polyurethane hot melt adhesive. The preparation of the relevant specimens was carried out in accordance with the GB / T 7124-2008 standard, with the dimensions of the bonded substrate (length × width × thickness: 100mm × 25mm × 1.6mm) and the gluing area (12.5mm × 25mm). The adhesive was placed on the gluing area and fixed with a metal clip. It was placed in an oven and heated at 140°C for 20 minutes. After cooling for different times, the bonding performance was tested. The tensile rate was set to 5mm min -1 During the test, the maximum value of the tensile shear force is taken and calculated according to the formula (bonding strength (MPa) = Fmax / 12.5×25).

[0062] Characterization of reusability: The specimens after the above bonding test were fixed with metal clips and placed in an oven for heating at 140°C for 20 minutes. After cooling, they were placed for one day to test the tensile shear strength.

[0063] Example 1

[0064] By mass, 500 parts of polybutylene adipate diol were placed under vacuum conditions at 120°C for dehydration for 2 hours. After cooling to 80°C, 90 parts of N,N'-(4,4'-methylenediphenyl)bismaleimide and 49 parts of furfuryl alcohol were added in sequence (the molar ratio of N,N'-(4,4'-methylenediphenyl)bismaleimide and furfuryl alcohol was fixed at 1:2). After reacting for 1 hour under nitrogen protection, 132 parts of 4,4'-methylenebis(phenyl isocyanate) were added and reacted for 2 hours. Then, after heating to 130°C, 76 parts of curing agent hexamethylene diisocyanate trimer were added and the reaction was continued for 5 minutes. After being transferred to a 100°C oven and continued to react for 12 hours, vacuum degassing was carried out under a pressure of 0.1 MPa for 5 minutes to obtain a one-component functional polyurethane adhesive, which was recorded as CDAPU2.

[0065] Example 2

[0066] By mass, 500 parts of polybutylene adipate diol were placed under vacuum conditions at 120°C for dehydration for 2 hours. After cooling to 80°C, 180 parts of N,N'-(4,4'-methylenediphenyl)bismaleimide and 99 parts of furfuryl alcohol were added in sequence (the molar ratio of N,N'-(4,4'-methylenediphenyl)bismaleimide and furfuryl alcohol was fixed at 1:2). After reacting for 1 hour under nitrogen protection, 232 parts of 4,4'-methylenebis(phenyl isocyanate) were added and reacted for 2 hours. Then, after heating to 130°C, 26 parts of curing agent hexamethylene diisocyanate trimer were added and the reaction was continued for 5 minutes. After transferring to a 100°C oven and continuing to react for 12 hours, vacuum degassing was carried out under a pressure of 0.1 MPa for 5 minutes to obtain a one-component functional polyurethane adhesive, which was recorded as CDAPU3.

[0067] Example 3

[0068] By mass, 500 parts of polybutylene adipate diol were placed under vacuum conditions at 120°C for dehydration for 2 hours. After cooling to 80°C, 180 parts of N,N'-(4,4'-methylenediphenyl)bismaleimide and 99 parts of furfuryl alcohol were added in sequence (the molar ratio of N,N'-(4,4'-methylenediphenyl)bismaleimide and furfuryl alcohol was fixed at 1:2). After reacting for 1 hour under nitrogen protection, 194 parts of 4,4'-methylenebis(phenyl isocyanate) were added and reacted for 2 hours. Then, after heating to 130°C, 76 parts of curing agent hexamethylene diisocyanate trimer were added and the reaction was continued for 5 minutes. After transferring to a 100°C oven and continuing to react for 12 hours, vacuum degassing was carried out under a pressure of 0.1 MPa for 5 minutes to obtain a one-component functional polyurethane adhesive, which was recorded as CDAPU4.

[0069] Comparative Example 1

[0070] By mass, 500 parts of polybutylene adipate diol were placed at 120°C under vacuum conditions for dehydration for 2 hours. After cooling to 80°C, 90 parts of N,N'-(4,4'-methylenediphenyl)bismaleimide and 49 parts of furfuryl alcohol were added in sequence (the molar ratio of N,N'-(4,4'-methylenediphenyl)bismaleimide to furfuryl alcohol was fixed at 1:2). After reacting for 1 hour under nitrogen protection, 182 parts of 4,4'-methylenebis(phenyl isocyanate) were added and reacted for 2 hours. Then, after heating to 130°C, 26 parts of curing agent hexamethylene diisocyanate trimer were added and the reaction was continued for 5 minutes. After transferring to a 100°C oven and continuing to react for 12 hours, vacuum degassing was carried out under a pressure of 0.1 MPa for 5 minutes to obtain a one-component functional polyurethane adhesive, which was recorded as CDAPU1.

[0071] Result description:

[0072] like Figure 2 The one-component functional polyurethane adhesive shown can be processed into various shapes. Figure 2 a: blocky; Figure 2 b: Hose; when used, you can choose according to the needs of hot pressing or dispensing.

[0073] like Figure 3 The mechanical and toughness comparisons of the examples (CDAPU2-4) and the control example (CDAPU1, breaking strength 18.6 MPa, elongation 633%) show that increasing the curing agent content (CDAPU2, breaking strength 24.4 MPa, elongation 533%) and the functional chain extender content (CDAPU3, breaking strength 39.8 MPa, elongation 376%) in the polyurethane adhesives all show a trend of increasing breaking strength but decreasing elongation. However, increasing the chain extender content alone significantly improves breaking strength. Increasing the curing agent content alone, while also improving breaking strength, hinders the formation of non-covalent interactions such as hydrogen bonds, resulting in a less significant improvement in strength. Increasing both the chain extender and curing agent content (CDAPU4, breaking strength 20.1 MPa, elongation 266%) increases the stiffness of the polyurethane but further constrains the molecular chains, hindering hydrogen bonding, resulting in a decrease in both strength and elongation.

[0074] like Figure 4 The processing performance comparison chart of the examples (CDAPU2-4) and the control example (CDAPU1, viscosity of 12253 mPa.s at 140°C) shows that with the increase of the curing agent content in the polyurethane adhesive (CDAPU2, viscosity of 5*10 at 140°C), the 6mPa.s), the processing viscosity of the adhesive increased significantly, resulting in a decrease in sizing performance. Increasing only the chain extender content (CDAPU3, viscosity of 5213mPa.s at 140°C) significantly improved the processing performance of the adhesive, because without changing the curing agent content, the dynamic chemical bond content will increase with the increase of the chain extender content, and the small molecule compounds released by thermal dissociation can be used as plasticizers in the system, further reducing the viscosity of the system and improving the sizing performance. While increasing the content of chain extender and curing agent at the same time (CDAPU4, viscosity of 14495mPa.s at 140°C), although there is also a small molecule plasticizing effect, due to the increase in cross-linking degree, the molecular chains are bound and the mobility is reduced, resulting in a relatively weakened sizing performance.

[0075] like Figure 5The comparative graph of the bonding performance of the examples (CDAPU2-4) and the control example (CDAPU1, initial adhesion 1.81 MPa, final adhesion 5.92 MPa) on aluminum alloy shows that as the curing agent content in the polyurethane adhesive increases (CDAPU2, initial adhesion 1.75 MPa, final adhesion 3.47 MPa), the adhesive's sizing performance decreases, resulting in a weakened ability to penetrate the adhesive material, resulting in weaker bonding compared to the control group. Increasing the chain extender content alone (CDAPU3, initial adhesion 5.2 MPa, final adhesion 13.3 MPa) significantly improves the adhesive's initial and final adhesion. This is due, in part, to the enhanced penetration into the substrate caused by the improved sizing performance of the adhesive. Simultaneously, the small molecules released by dissociation have a thermal etching effect on the substrate, further enhancing the interfacial interaction between the adhesive and the substrate, resulting in a significant improvement in bonding performance. While increasing the content of chain extender and curing agent at the same time (CDAPU4, initial adhesion 8.35MPa, final adhesion 8.05MPa), although the sizing performance is relatively weakened, the thermal etching ability is comparable to that of CDAPU3, so the initial adhesion performance is improved but the final adhesion strength is weakened relative to CDAPU3. Overall, CDAPU3 is the best ratio, and its bonding strength with curing time, bonding ability to different substrates and reusability are further explored. First, its initial bonding strength (5min) to stainless steel and aluminum alloy exceeds 5MPa, which is significantly higher than the bonding strength of commercially available single-component polyurethanes. At the same time, its initial bonding strength (7 days) to stainless steel and aluminum alloy exceeds 12MPa, which can meet the needs of practical applications. CDAPU3 has a bonding strength of ≥10MPa for metal materials, ≥9MPa for plastics (epoxy resin), and ≥15MPa for composite materials (fiberglass board). The resulting damage is all colloidal damage. The bonding strength for wood (pine) is ≥7MPa, and the resulting damage is material damage, fully demonstrating the strong bonding ability of the one-component functional polyurethane adhesive of the present invention to various types of substrates. Finally, the repeated bonding ability of CDAPU3 to aluminum alloy was explored. The results showed that the bonding strength was slightly improved after the second bonding, demonstrating the reusability of the one-component functional polyurethane adhesive.

[0076] like Figure 6 The example (CDAPU3) demonstrates the bonding performance of nylon fabric. Due to its low surface energy and crystallinity, nylon is typically difficult to wet with adhesives, making it difficult to achieve a good bond without treatment. The one-component functional polyurethane adhesive of the present invention exhibits strong bonding strength and excellent sizing properties, with strong permeability to nylon fabric. In the absence of surface treatment, the adhesive achieves a peel force of approximately 7.5 N / 25 mm within a 30-80 mm peel range (common polyurethane adhesives offer approximately 5 N / 25 mm), demonstrating excellent bonding to nylon fabric.

Claims

1. A polyurethane adhesive, characterized in that: By mass, the components include:

2. The polyurethane adhesive according to claim 1, characterized in that: The isocyanate is a polyisocyanate; The relative molecular weight of the macromolecular polyol is 600-4000; The macromolecular polyol is one or more of polyether polyol and polyester polyol; The curing agent includes one or more of a trimer formed by isocyanate and a triisocyanate.

3. The polyurethane adhesive according to claim 2, characterized in that: The polyisocyanate is one or more of aromatic polyisocyanate and aliphatic polyisocyanate; The trimer formed by the isocyanate includes one or more of hexamethylene diisocyanate trimer, isophorone diisocyanate trimer, diphenylmethane diisocyanate trimer, toluene diisocyanate trimer, and pentamethylene diisocyanate trimer; the triisocyanate includes one or more of triphenylmethane triisocyanate, tris(isocyanate phenyl)thiophosphate, and 1,6,10-undecane triisocyanate.

4. The polyurethane adhesive according to claim 1, characterized in that: The raw material components of the chain extender include alcohol and / or amine, and a compound containing a maleimide functional group.

5. The polyurethane adhesive according to claim 4, characterized in that: The alcohol is an alcohol containing a furan ring group; the amine is a diamine containing a furan ring group; the compound having a maleimide functional group is one or more of N,N'-(4,4'-methylenediphenyl)bismaleimide and m-phenylenebismaleimide; The molar ratio of the alcohol and / or amine to the compound containing maleimide functional group in the chain extender is 0.1-2:

1.

6. A method for preparing the polyurethane adhesive according to claim 1, comprising: The components are weighed according to their mass fractions, and the raw material components of the macromolecular polyol and the chain extender are mixed, reacted under an inert protective gas, and then isocyanate is added to react, and then a curing agent is added to continue the reaction to obtain a polyurethane adhesive.

7. The preparation method according to claim 6, characterized in that: The macromolecular polyol is a pretreated macromolecular polyol; The inert protective gas includes nitrogen or argon; The reaction is carried out at 60-100° C. under an inert protective gas for 0.5-4 h; The adding of isocyanate to react and then adding a curing agent to continue the reaction comprises: adding isocyanate to react at 60-140° C. for 1-24 hours, then adding a curing agent to react at 60-140° C. for 0.05-2 hours, further reacting the resulting reaction solution at 50-150° C. in a vacuum oven for 2-14 hours, and vacuum degassing for 5-10 minutes under a pressure of 0.05-0.1 MPa.

8. A bonding member, characterized in that: The bonding member comprises the polyurethane adhesive according to claim 1.

9. The adhesive member according to claim 1, wherein: The adhesive can be removed and / or reused as needed under thermal stimulation.

10. Use of the polyurethane adhesive according to claim 1 and the bonding member according to claim 8 in scenarios requiring reversible disassembly and reuse.

Images