Hot-melt double-faced adhesive tape and preparation method thereof

Abstract

The invention provides a hot-melt double-faced adhesive tape and a preparation method thereof, and the hot-melt double-faced adhesive tape comprises the following components in parts by weight: 40-60 parts of SEBS thermoplastic elastomer, 10-20 parts of polyisobutene, 5-10 parts of modified polyurethane, 3-7 parts of modified tackifier, 6-12 parts of mineral oil, 1-3 parts of modified nano silicon dioxide and 0.5-1.5 parts of antioxidant. The modified polyurethane is polyurethane modified by polydimethylsiloxane and a silane coupling agent; the modified tackifier is obtained by carrying out dehydration reaction on triethyl borate, boric acid glycerin, borate and silicon hydroxyl; the modified nano silicon dioxide is chitosan modified nano silicon dioxide; and the antioxidant is dilauryl thiodipropionate. The hot-melt double-sided adhesive tape has no viscosity initially, can be tightly bonded with materials such as aluminum foil and nylon under high-temperature and high-pressure conditions, and has excellent electrolyte resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of double-sided adhesives, and specifically relates to a hot-melt double-sided adhesive and a preparation method thereof. Background Art

[0002] Double-sided adhesive is an adhesive material widely used in bonding, fixing and sealing. It usually consists of two layers of pressure-sensitive adhesives and a substrate (such as paper, cloth, plastic film, etc.). Double-sided adhesives have the characteristics of simple operation, strong adhesive force and wide application range, and are widely used in industries, construction, electronics, packaging, office and other fields. The substrate is the core part of the double-sided adhesive, which plays a role in supporting and separating the two layers of pressure-sensitive adhesives. The choice of substrate depends on the application requirements of the double-sided adhesive.

[0003] Pressure-sensitive adhesive is the key component of double-sided adhesive, which can quickly generate adhesive force after applying slight pressure. Common types of pressure-sensitive adhesives include: Rubber-based adhesives: Made from natural or synthetic rubbers, they have excellent initial adhesion and holding power, and are suitable for bonding most common materials, but have poor weather resistance and chemical resistance. Acrylic-based adhesives: Polymerized from acrylate monomers, they have excellent weather resistance, chemical resistance and transparency, and are suitable for applications in outdoor and harsh environments. Silicone-based adhesives: Made from siloxane polymers, they have extremely high temperature resistance and chemical resistance, and are suitable for applications in high-temperature, low-temperature and corrosive environments. Hot-melt adhesives: Applied on the substrate after heating and melting, and form an adhesive effect after cooling, which is suitable for occasions that require rapid curing.

[0004] Patent CN118126645A provides a fireproof and flame-retardant foam double-sided adhesive, which includes a foam carrier layer with a thickness of 30 - 1000 μm and at least one adhesive layer with a dry adhesive thickness of 100 - 500 μm; the raw materials of the adhesive layer include the following materials in parts by weight: quaternary ammonium salt-modified acrylic acid 15 - 40 parts, isooctyl acrylate 20 - 40 parts, tackifying resin 20 - 30 parts, nano-silica 8 - 10 parts, dodecyl mercaptan 2 - 3 parts, non-ionic surfactant 2 - 4 parts, second flame retardant 1 - 2 parts, flame retardant aid 0.5 - 1 part. The preparation method steps include: preparing the foam carrier layer; preparing the adhesive layer; coating the adhesive layer on both sides of the foam carrier layer and then drying; then covering a release film on the adhesive layer to obtain the foam double-sided adhesive. This kind of foam double-sided adhesive with excellent fireproof and flame-retardant properties, high temperature resistance and long-lasting viscosity makes the double-sided adhesive not easily affected by high temperature during use, and extends the service life of the double-sided adhesive.

[0005] At present, the adhesive part of double-sided tape mostly uses pressure-sensitive adhesive, and there are many types of pressure-sensitive adhesives presented. Among them, hot-melt pressure-sensitive adhesive is widely used due to its excellent properties such as non-polluting the environment, simple manufacturing, and convenient use. Existing double-sided tape products still have some other problems, such as weak initial adhesion and insufficient strength during peeling. These problems further highlight the comprehensive performance disadvantages of traditional double-sided tape when meeting the requirements of high-performance electronic devices. Summary of the Invention

[0006] The purpose of the present invention is to provide a hot-melt double-sided tape. By preparing the hot-melt double-sided tape with materials such as SEBS thermoplastic elastomer, polyisobutylene, modified polyurethane, and modified tackifier, it has no initial stickiness and can be tightly bonded to materials such as aluminum foil and nylon under high temperature and high pressure conditions. At the same time, it has excellent electrolyte resistance. When applied to polymer lithium batteries, it can effectively solve the delamination between the bare battery core and the aluminum-plastic film.

[0007] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0008] A hot-melt double-sided tape, comprising the following components in parts by weight: 40-60 parts of SEBS thermoplastic elastomer, 10-20 parts of polyisobutylene, 5-10 parts of modified polyurethane, 3-7 parts of modified tackifier, 6-12 parts of mineral oil, 1-3 parts of modified nano-silica, and 0.5-1.5 parts of antioxidant.

[0009] Furthermore, the modified polyurethane is poly(dimethylsiloxane) and silane coupling agent modified polyurethane.

[0010] Furthermore, the modified tackifier is obtained by the dehydration reaction of triethyl borate, glycerol borate, borate and silanol groups.

[0011] Furthermore, the modified nano-silica is chitosan modified nano-silica.

[0012] Furthermore, the antioxidant is dilauryl thiodipropionate.

[0013] Furthermore, the viscosity of the mineral oil is 25-35 cSt.

[0014] A preparation method of a hot-melt double-sided tape, comprising the following steps:

[0015] S1: Take 40-60 parts of SEBS thermoplastic elastomer, 10-20 parts of polyisobutylene and 5-10 parts of modified polyurethane, and mix them at a temperature of 160-180 °C for 40-60 min;

[0016] S2: Cool down to 120-140 °C, add 3-7 parts of modified tackifier, 1-3 parts of modified nano-silica and 6-12 parts of mineral oil to step S1, and continue stirring and reacting for 1-3 h;

[0017] S3: Cool down to 90 - 100 °C, add 0.5 - 1.5 parts of antioxidant to step S2, and stir and react for 25 - 35 min to obtain the hot melt double-sided adhesive.

[0018] Furthermore, the preparation process of the modified polyurethane in step S1 is as follows: Take 10 - 20 parts of polydimethylsiloxane, 1 - 3 parts of N-[3-(trimethoxysilyl)propyl]ethylenediamine, and 35 - 45 parts of polyurethane and mix them, and react at a temperature of 110 - 130 °C for 1.5 - 2.5 h.

[0019] Furthermore, the preparation process of the modified tackifier in step S2 is as follows: Take 3 - 6 parts of triethyl borate, 4 - 7 parts of glycerol borate, 1 - 3 parts of sodium borate, and 4 - 8 parts of silanol and mix them, and perform dehydration condensation reaction at a temperature of 120 - 130 °C for 2 - 3 h.

[0020] Furthermore, the preparation process of the modified nano-silica in step S2 is as follows: Take 3 - 6 parts of chitosan, 10 - 20 parts of deionized water, and 5 - 10 parts of nano-silica and mix them, and stir and react at a temperature of 100 - 110 °C for 1 - 2 h; then obtain the product through filtration, washing, and drying.

[0021] SEBS (styrene-ethylene / butylene-styrene block copolymer) is a thermoplastic elastomer (TPE) and belongs to the family of styrenic block copolymers (SBCs). SEBS is prepared by hydrogenating SBS (styrene-butadiene-styrene block copolymer), in which the butadiene chain segments are hydrogenated into saturated ethylene-butylene chain segments, thereby significantly improving the heat resistance, weather resistance, and chemical stability of the material.

[0022] Polyisobutylene (PIB) is a linear or branched polymer prepared by polymerizing isobutene (2-methylpropene) monomers. It has excellent chemical stability, low gas permeability, and good flexibility, and is widely used in many fields such as sealing materials, lubricants, adhesives, medicine, and food packaging.

[0023] Polydimethylsiloxane (PDMS) is a linear organosilicon polymer composed of repeating dimethylsiloxane units. PDMS is one of the most common components in silicone rubber and silicone oil, and has excellent physical and chemical properties, and is widely used in many fields such as lubricants, sealing materials, cosmetics, medical devices, and electronic packaging.

[0024] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0025] The present invention uses SEBS thermoplastic elastomer and polyisobutene as the main body, and at the same time adds components such as modified polyurethane, modified tackifier, and modified nano-silica to obtain a double-sided adhesive that is initially non-tacky but can be tightly adhered to materials such as aluminum foil and nylon under high temperature and high pressure conditions. By modifying polyurethane with polydimethylsiloxane and silane coupling agent, and utilizing the good hydrophobicity, high and low temperature resistance, and weather resistance of polysiloxane, the hydrophobicity and excellent surface touch of polyurethane can be better improved, and the advantages of polyurethane and the characteristics of polysiloxane can be integrated. By using triethyl borate, glycerol borate, borate and silicon hydroxyl to obtain a modified tackifier, a silicon-boron bond is formed through the reaction between borate and silicon hydroxyl. This chemical bond has high stability and strength, which helps to improve the adhesion performance and heat resistance; modifying nano-silica with chitosan can reduce agglomeration during the nucleation process, and the obtained modified nano-silica is uniform, stable and has good dispersibility. Detailed Embodiments

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0027] A hot-melt double-sided adhesive in this embodiment includes the following components in parts by weight: 40-60 parts of SEBS thermoplastic elastomer, 10-20 parts of polyisobutene, 5-10 parts of modified polyurethane, 3-7 parts of modified tackifier, 6-12 parts of mineral oil, 1-3 parts of modified nano-silica, and 0.5-1.5 parts of antioxidant.

[0028] The modified polyurethane in this embodiment is a polyurethane modified with polydimethylsiloxane and silane coupling agent.

[0029] The modified tackifier in this embodiment is obtained by the dehydration reaction of triethyl borate, glycerol borate, borate and silicon hydroxyl.

[0030] The modified nano-silica in this embodiment is nano-silica modified with chitosan.

[0031] The antioxidant in this embodiment is dilauryl thiodipropionate.

[0032] The viscosity of the mineral oil in this embodiment is 25-35 cSt.

[0033] A preparation method of a hot-melt double-sided adhesive in this embodiment includes the following steps:

[0034] S1: Take 40 - 60 parts of SEBS thermoplastic elastomer, 10 - 20 parts of polyisobutylene, and 5 - 10 parts of modified polyurethane, and mix them at a temperature of 160 - 180 °C for 40 - 60 min;

[0035] S2: Cool down to 120 - 140 °C, add 3 - 7 parts of modified tackifier, 1 - 3 parts of modified nano - silica, and 6 - 12 parts of mineral oil to step S1, and continue stirring and reacting for 1 - 3 h;

[0036] S3: Cool down to 90 - 100 °C, add 0.5 - 1.5 parts of antioxidant to step S2, stir and react for 25 - 35 min, and then the hot - melt double - sided adhesive can be obtained.

[0037] In the preparation process of the modified polyurethane described in step S1 of this embodiment: Take 10 - 20 parts of polydimethylsiloxane, 1 - 3 parts of N - [3 - (trimethoxysilyl)propyl]ethylenediamine, and 35 - 45 parts of polyurethane, and react them at a temperature of 110 - 130 °C for 1.5 - 2.5 h.

[0038] In the preparation process of the modified tackifier described in step S2 of this embodiment: Take 3 - 6 parts of triethyl borate, 4 - 7 parts of glycerol borate, 1 - 3 parts of sodium borate, and 4 - 8 parts of silanol, and perform dehydration and condensation reaction at a temperature of 120 - 130 °C for 2 - 3 h.

[0039] In the preparation process of the modified nano - silica described in step S2 of this embodiment: Take 3 - 6 parts of chitosan, 10 - 20 parts of deionized water, and 5 - 10 parts of nano - silica, and stir and react at a temperature of 100 - 110 °C for 1 - 2 h; then obtain the product through filtration, washing, and drying.

[0040] The raw materials used in the present invention are as follows:

[0041] Polydimethylsiloxane (Shanghai Yuanye Bio - Technology Co., Ltd., product number Y19525); N - [3 - (trimethoxysilyl)propyl]ethylenediamine (Wuhan Xinxin Jiali Bio - Technology Co., Ltd., product number 10021); Polyurethane (Shanghai Juqian New Materials Development Co., Ltd., product catalog 66); SEBS thermoplastic elastomer (Dongguan Bailing New Materials Co., Ltd., grade G1701MU); Polyisobutylene (Shanghai Yuanye Bio - Technology Co., Ltd., product number S22214); Triethyl borate (Hubei Shiteng Chemical Technology Co., Ltd., product number 0213); Glycerol borate (Shanghai Zhenzhun Bio - Technology Co., Ltd., product number ZL - 20680); Silanol (Hubei Xinkang Pharmaceutical Chemical Co., Ltd., product number XK1385); Chitosan (Shanghai Yuanye Bio - Technology Co., Ltd., product number S11064); Mineral oil (Shanghai Yuanye Bio - Technology Co., Ltd., product number S68179); Dilauryl thiodipropionate (Shanghai Yuanye Bio - Technology Co., Ltd., product number S67529).

[0042] Example 1

[0043] This example provides a preparation method for a hot-melt double-sided adhesive, which includes the following steps:

[0044] S1: Take 10 g of polydimethylsiloxane, 1 g of N-[3-(trimethoxysilyl)propyl]ethylenediamine and 35 g of polyurethane, mix them, and stir and react at a temperature of 110 °C at a rate of 600 r / min for 1.5 h to obtain modified polyurethane;

[0045] Take 40 g of SEBS thermoplastic elastomer, 10 g of polyisobutene and 5 g of modified polyurethane, mix them at a temperature of 160 °C at a rate of 400 r / min for 40 min to obtain mixture A;

[0046] S2: Take 3 g of triethyl borate, 4 g of glycerol borate, 1 g of sodium borate and 4 g of silanol, mix them, and perform dehydration condensation reaction at a temperature of 120 °C for 2 h to obtain modified tackifier;

[0047] Take 3 g of chitosan, 10 g of deionized water and 5 g of nano-silica, mix them, and stir and react at a temperature of 100 °C at a rate of 500 r / min for 1 h; then obtain modified nano-silica after filtration, washing with distilled water 3 times and drying at 80 °C for 1 h;

[0048] Cool down to 120 °C, add 3 g of modified tackifier, 1 g of modified nano-silica and 6 g of mineral oil to the mixture A in step S1, and continue to stir and react at a rate of 600 r / min for 3 h to obtain mixture B;

[0049] S3: Cool down to 90 °C, add 0.5 g of antioxidant dilauryl thiodipropionate to step S2, and stir and react at a rate of 500 r / min for 25 min to obtain the hot-melt double-sided adhesive.

[0050] Example 2

[0051] This example provides a preparation method for a hot-melt double-sided adhesive, which includes the following steps:

[0052] S1: Take 20 g of polydimethylsiloxane, 3 g of N-[3-(trimethoxysilyl)propyl]ethylenediamine and 45 g of polyurethane, mix them, and stir and react at a temperature of 130 °C at a rate of 600 r / min for 2.5 h to obtain modified polyurethane;

[0053] Take 60 g of SEBS thermoplastic elastomer, 20 g of polyisobutene and 10 g of modified polyurethane, mix them at a temperature of 180 °C for 60 min to obtain mixture A;

[0054] S2: Mix 6 g of triethyl borate, 7 g of boric acid glycerol, 3 g of sodium borate and 8 g of silanol, and perform dehydration condensation reaction at 130 °C for 3 h to obtain a modified tackifier;

[0055] Mix 6 g of chitosan, 20 g of deionized water and 10 g of nano-silica, and stir and react at 110 °C at a rate of 500 r / min for 2 h; then obtain modified nano-silica through filtration, washing with distilled water 3 times, and drying at 80 °C for 1 h;

[0056] Cool down to 140 °C, add 7 g of the modified tackifier, 3 g of the modified nano-silica and 12 g of mineral oil to the mixture A in step S1, and continue to stir and react at a rate of 600 r / min for 1 h to obtain a mixture B;

[0057] S3: Cool down to 100 °C, add 1.5 g of antioxidant dilauryl thiodipropionate to step S2, and stir and react at a rate of 500 r / min for 35 min to obtain the hot melt double-sided adhesive.

[0058] Example 3

[0059] This example provides a preparation method of a hot melt double-sided adhesive, including the following steps:

[0060] S1: Mix 15 g of polydimethylsiloxane, 2 g of N-[3-(trimethoxysilyl)propyl]ethylenediamine and 40 g of polyurethane, and stir and react at 125 °C at a rate of 600 r / min for 2 h to obtain a modified polyurethane;

[0061] Mix 55 g of SEBS thermoplastic elastomer, 15 g of polyisobutene and 7 g of the modified polyurethane at 170 °C for 50 min to obtain a mixture A;

[0062] S2: Mix 5 g of triethyl borate, 6 g of boric acid glycerol, 2 g of sodium borate and 6 g of silanol, and perform dehydration condensation reaction at 125 °C for 2.5 h to obtain a modified tackifier;

[0063] Mix 5 g of chitosan, 14 g of deionized water and 7 g of nano-silica, and stir and react at 106 °C at a rate of 500 r / min for 1.5 h; then obtain modified nano-silica through filtration, washing with distilled water 3 times, and drying at 80 °C for 1 h;

[0064] Cool down to 135 °C, add 5 g of the modified tackifier, 2 g of the modified nano-silica and 10 g of mineral oil to the mixture A in step S1, and continue to stir and react at a rate of 600 r / min for 2.5 h to obtain a mixture B;

[0065] S3: Cool down to 95°C, add 1 g of the antioxidant dilauryl thiodipropionate to Step S2, and stir and react at a rate of 500 r / min for 30 min to obtain the hot melt double-sided adhesive.

[0066] Comparative Example 1

[0067] The difference between this comparative example and Example 1 is that no modified polyurethane is added in Step S1, and the other steps are the same.

[0068] Comparative Example 2

[0069] The difference between this comparative example and Example 1 is that the modified polyurethane in Step S1 is directly replaced with unmodified polyurethane, and the other steps are the same.

[0070] Comparative Example 3

[0071] The difference between this comparative example and Example 1 is that no modified tackifier is added in Step S2, and the other steps are the same.

[0072] Comparative Example 4

[0073] The difference between this comparative example and Example 1 is that no modified nano-silica is added in Step S2, and the other steps are the same.

[0074] Comparative Example 5

[0075] The difference between this comparative example and Example 1 is that unmodified nano-silica is used to replace the modified nano-silica in Step S3, and the other steps are the same.

[0076] Performance test:

[0077] The hot melt double-sided adhesives of each example and comparative example are respectively tested for the hot pressing peel strength at 1 MPa after being soaked in the electrolyte at 85°C (ethylene carbonate: ethyl methyl carbonate: dimethyl carbonate = 4:2:4) for 48 h according to the method in GB / T2792-2014. The adhesion substrate of the hot melt adhesive layer is aluminum foil, and the results are shown in the table.

[0078] The 180° peel strength of the test samples is tested according to GB / T 2792-1998; the holding tack of the test samples is tested according to GB / T7753-1987. The results are as follows in the table:

[0079] Table 1 Performance test results

[0080] Test Peeling force kgf / 25mm Holding adhesion Electrolyte resistance Example 1 4.46 60 Flatly attached to the aluminum foil, without wrinkles and warping Example 2 4.49 61 Flatly attached to the aluminum foil, without wrinkles and warping Example 3 4.52 62 Flatly attached to the aluminum foil, without wrinkles and warping Comparative example 1 2.51 28 With warping and wrinkles Comparative example 2 3.87 53 With slight warping and wrinkles Comparative example 3 2.46 26 With warping and wrinkles Comparative example 4 2.54 31 With warping and wrinkles Comparative example 5 3.76 51 With slight warping and wrinkles

[0081] From the above performance test results, it can be seen that the hot-melt double-sided adhesives prepared in Examples 1-3 have no initial adhesion, but can be tightly adhered to materials such as aluminum foil and nylon under high temperature and high pressure, and have good performance; in particular, the comprehensive performance of Example 3 is the most prominent. However, Comparative Examples 1-5 are significantly worse than the examples in the corresponding performance tests because they do not adopt the necessary technical solutions. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0082] By using triethyl borate, glycerol borate, borate and silanol to obtain a modified tackifier, a silicon-boron bond is formed through the reaction between borate and silanol. This chemical bond has high stability and strength, which helps to improve the adhesion performance and heat resistance; modifying nano-silica with chitosan can reduce agglomeration during the nucleation process, and the obtained modified nano-silica is uniform, stable and has good dispersibility.

[0083] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A hot melt double-sided adhesive, characterized in that: The invention comprises the following components in parts by weight: 40-60 parts of SEBS thermoplastic elastomer, 10-20 parts of polyisobutylene, 5-10 parts of modified polyurethane, 3-7 parts of modified tackifier, 6-12 parts of mineral oil, 1-3 parts of modified nano silicon dioxide and 0.5-1.5 parts of antioxidant.

2. A hot melt double-sided adhesive according to claim 1, characterized in that: The modified polyurethane is polyurethane modified by polydimethylsiloxane and silane coupling agent.

3. A hot melt double-sided adhesive according to claim 1, characterized in that: The modified tackifier is obtained by dehydration reaction of triethyl borate, boric acid glycerol, borate and silanol.

4. The hot melt double-sided adhesive according to claim 1, characterized in that: The modified nano silicon dioxide is chitosan modified nano silicon dioxide.

5. The hot melt double-sided adhesive according to claim 1, characterized in that: The antioxidant is didodecanol thiodipropionate.

6. The hot melt double-sided adhesive according to claim 1, characterized in that: The viscosity of the mineral oil is 25-35 cSt.

7. A method for preparing a hot melt double-sided adhesive, characterized in that: The steps include: S1: Take 40-60 parts of SEBS thermoplastic elastomer, 10-20 parts of polyisobutylene and 5-10 parts of modified polyurethane, and mix them at a temperature of 160-180°C for 40-60 minutes; S2: Cool down to 120-140°C, add 3-7 parts of modified tackifier, 1-3 parts of modified nano-silicon dioxide and 6-12 parts of mineral oil to step S1, and continue stirring to react for 1-3 hours; S3: Cooling to 90-100° C., adding 0.5-1.5 parts of antioxidant to step S2, stirring and reacting for 25-35 minutes, and obtaining the hot melt double-sided adhesive.

8. The method for preparing a hot melt double-sided adhesive according to claim 7, characterized in that: The preparation process of the modified polyurethane in step S1 is: 10-20 parts of polydimethylsiloxane, 1-3 parts of N-[3-(trimethoxysilyl)propyl]ethylenediamine and 35-45 parts of polyurethane are mixed and reacted at a temperature of 110-130° C. for 1.5-2.5 hours.

9. The method for preparing a hot melt double-sided adhesive according to claim 7, characterized in that: The preparation process of the modified tackifier in step S2 is: 3-6 parts of triethyl borate, 4-7 parts of boric acid glycerol, 1-3 parts of sodium borate and 4-8 parts of silanol are mixed and dehydrated and condensed at a temperature of 120-130° C. for 2-3 hours.

10. The method for preparing a hot melt double-sided adhesive according to claim 7, characterized in that: The preparation process of the modified nano-silica in step S2 is: 3-6 parts of chitosan, 10-20 parts of deionized water and 5-10 parts of nano-silica are mixed, and stirred at a temperature of 100-110° C. for 1-2 hours; and then filtered, washed and dried.