Double-sided adhesive tape for pasting low-surface-energy material and preparation method of double-sided adhesive tape

Abstract

The invention provides a double-sided adhesive tape for pasting a low-surface-energy material and a preparation method of the double-sided adhesive tape. The adhesive tape is of a four-layer structure and comprises an acrylate pressure-sensitive adhesive layer and the like. Through selection of raw materials and design of a macromolecular structure, good wetting and bonding of a low-polarity base material are realized by utilizing an acrylic acid long-chain alkyl ester chain segment, and the problem that a low-surface-energy material is difficult to bond is solved. The adhesive formula used in the invention contains a special chain segment, has strong affinity with a low-polarity base material, and has a good bonding effect; polymerization reaction design is ingenious, and polymer performance is ensured; the monomer combination is reasonable, the compatibility is ensured, the polarity is reduced, an effective solution is provided for bonding of low-surface-energy materials, and the method has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of adhesive tapes, and in particular to a double-sided adhesive tape having high or permanent adhesion to low surface energy materials and a preparation method thereof. Background Art

[0002] With the vigorous development of modern industry, various new materials are used in the electronics, electrical appliances, automobile and other industries. In the manufacturing process of these products, higher requirements are also put forward for various functional materials. Double-sided tape is widely used in all aspects of industrial processes as a simple and efficient anchoring material. PP, PE or their composite materials are also widely used in a large number of product designs as engineering plastics with excellent performance. Compared with high-polarity materials such as stainless steel and ABS, PP and PE have lower polarity, so it is difficult for ordinary tapes and adhesives to produce strong adhesion on their surfaces, thereby achieving strong bonding.

[0003] Different solutions have also emerged in the industry for the bonding of low surface energy materials. For example, a common solution is to use silicone pressure-sensitive adhesive to achieve the bonding of low-energy surface materials such as PE and PP, but silicone adhesives are generally more expensive. Patent CN109777309A discloses a method for manufacturing double-sided tape for low surface energy bonding. The invention uses toluene as a solvent to dissolve and mix synthetic rubber, natural rubber, tackifying resin, photoinitiator and other auxiliary materials into a pressure-sensitive adhesive. The invention uses toluene as a solvent, which causes great pollution to construction workers and the environment, and has high requirements for the coating and curing process. The technology disclosed in patent CN105255411A uses organosiloxane coupling agents and chlorinated polypropylene to modify acrylate adhesives to achieve the bonding function of low-energy surface materials. However, the introduction of halogens has brought new environmental problems.

[0004] Therefore, it is particularly necessary to develop a solution that can effectively bond low surface energy materials such as PP and PE while avoiding high costs, reducing environmental pollution and avoiding the introduction of new environmental problems. This can not only meet the demand of modern industry for high-performance adhesive materials, but also promote the sustainable development of related industries. Summary of the invention

[0005] The present invention mainly utilizes a large amount of {C2H4} n The chain segments are used to achieve a better wetting effect on low polar substrates such as PE and PP. At the same time, with the special polymerization process design, the lower addition amount of polar monomers such as acrylic acid and hydroxyethyl acrylate, and the selection of low acid value tackifying resin, the double-sided tape finally obtained has a good bonding effect on low surface energy materials such as PP and PE, solving the industry problem that low surface energy materials are difficult to bond.

[0006] In order to achieve the above-mentioned purpose, the present invention provides, on the one hand, a double-sided tape for pasting low surface energy materials, characterized in that it comprises a tape body, the tape body is a four-layer structure, including a first adhesive layer, a body reinforcement layer, a second adhesive layer and a release protective layer; the first adhesive layer is above the body reinforcement layer; the body reinforcement layer is above the second adhesive layer; the second adhesive layer is above the release protective layer.

[0007] Furthermore, the first adhesive layer and the second adhesive layer are both acrylate pressure-sensitive adhesive layers, and the acrylate pressure-sensitive adhesive layers include the following raw materials in parts by weight: 100 parts of acrylate polymer solution, 5-20 parts of tackifying resin, and 0.2-1 part of cross-linking agent.

[0008] Furthermore, the acrylic pressure-sensitive adhesive layer is prepared by the following preparation steps:

[0009] Step 1, preparing an acrylate polymer solution: adding a first monomer, a part of the second monomer, a part of the functional monomer and a solvent into a reaction container equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, stirring while heating to a certain temperature through N2, and then adding an initiator to react for 60-90 minutes; then using a dropping funnel to uniformly add the remaining second monomer, functional monomer, solvent and initiator mixture dropwise over a certain period of time, and after the dropwise addition is completed, heat preservation and reaction for 4-6 hours, thereby obtaining an acrylate polymer solution;

[0010] Step 2, preparing a pressure-sensitive adhesive solution before coating: the acrylate polymer solution prepared in step 1, the tackifying resin, the cross-linking agent and the diluent are stirred and mixed uniformly to prepare a pressure-sensitive adhesive solution to be coated.

[0011] Furthermore, the acrylic ester polymer solution comprises the following components in parts by weight: 40-60 parts of a first monomer, 40-60 parts of a second monomer, 1-3 parts of acrylic acid, 0.5-2 parts of hydroxyethyl acrylate, 100-120 parts of ethyl acetate, and 0.1-0.3 parts of an initiator.

[0012] Furthermore, the first monomer used in the preparation process of the acrylic ester polymer solution is one or more of lauryl acrylate, hexadecyl acrylate, octadecyl acrylate and behenyl acrylate.

[0013] Furthermore, it is characterized in that the second monomer used in the preparation process of the acrylic ester polymer solution is composed of 10-40 parts of isooctyl acrylate, 20-40 parts of butyl acrylate and 20-40 parts of methyl acrylate based on 100 parts of the total amount.

[0014] Furthermore, the solvent is one or more of ethyl acetate, butyl acetate, n-hexane and mixed solvents thereof.

[0015] Furthermore, the initiator is one or more of benzoyl peroxide, azobisisobutyronitrile, and azobisisoheptanenitrile.

[0016] Furthermore, the cross-linking agent is one or more of an isocyanate cross-linking agent, an epoxy cross-linking agent, and a metal salt cross-linking agent.

[0017] Furthermore, the tackifying resin is one or more of terpene and its derivative resins and rosin and its derivative resins; the softening point of the resin is 90-130° C., and the acid value is ≤30 (mgKOH / g).

[0018] Furthermore, the main body reinforcement layer is made of tissue paper or PET material, wherein the material thickness is 5 μm-100 μm.

[0019] Furthermore, the thickness of the first adhesive layer is 20-100 μm, and the thickness of the second adhesive layer is 20-100 μm.

[0020] In addition, the present invention also provides a method for preparing a double-sided adhesive tape for pasting low surface energy materials, which is characterized by comprising the following preparation steps:

[0021] Step 1: Fix the release protective layer on a special coating device, apply a certain amount of special pressure-sensitive adhesive for low surface energy materials as the second adhesive layer, dry to form a pressure-sensitive adhesive layer, transfer it to the main reinforcement layer (tissue paper or PET), and roll it up with the main reinforcement layer for standby use;

[0022] Step 2: Unroll the coiled material from step 1 on a special coating device, apply a certain amount of special pressure-sensitive adhesive for low surface energy materials on the other side of the main reinforcement layer (tissue paper or PET) as the first adhesive layer, cure it in a drying oven at 40°C for 3 days, and then roll it up to obtain a double-sided tape.

[0023] Compared with the prior art, the present invention has the following significant advantages:

[0024] 1. Unique segment structure brings good bonding effect. The long-chain alkyl acrylate in the formula of the present invention contains a large amount of {C2H4} n These soft segments have the same molecular chain structure as polyethylene, but are less polar. During bonding, these {C2H4} n The chain segments show excellent affinity with the same or similar chain segment structures in PE or PP substrates, thereby achieving excellent bonding effects.

[0025] 2. Specific polymerization reaction ensures polymer performance. All acrylic acid in the formula participates in the polymerization reaction of long-chain alkyl acrylate in the first stage. This design ensures that there are a large number of polar carboxyl groups in the polymer obtained by the first stage polymerization. In the second stage reaction, some carboxyl groups will form crosslinks with the hydroxyl groups of hydroxyethyl acrylate. At the same time, the presence of carboxyl groups can provide crosslinking points for the subsequent curing reaction and form hydrogen bonds in the film, thereby improving the cohesive strength.

[0026] 3. Reasonable monomer combination ensures polymer compatibility and reduces the polarity of the adhesive. Some monomers in the second monomer combination participate in the first stage reaction and react with long-chain alkyl acrylate to form a more complex macromolecular chain structure. This ensures that the polymer generated in the first stage has good compatibility with the polymer generated in the second stage. Relatively few polar monomers and tackifying resins with relatively low acid values ​​are used in the adhesive formula. This plays a positive role in reducing the overall polarity of the adhesive. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The figure is a schematic diagram of the structure of the double-sided adhesive tape provided by the present invention for pasting low surface energy materials. DETAILED DESCRIPTION

[0028] Example 1

[0029] Formula composition: first combination monomer: 80g of octadecyl acrylate; second combination monomer: 40g of isooctyl acrylate, 50g of butyl acrylate, 20g of methyl acrylate; 5g of acrylic acid, 2g of hydroxyethyl acrylate, 200g of ethyl acetate, 0.6g of initiator BPO, 20g of resin GB-110, and 2g of curing agent L-75.

[0030] Manufacturing process:

[0031] (1) 80 g of octadecyl acrylate, 5 g of acrylic acid, 20 g of the second combination mixed monomer and 120 g of ethyl acetate were added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, and heated to 80° C., 0.3 g of initiator BPO (dissolved in 10 g of ethyl acetate) was added to initiate the reaction, and the reaction was carried out at 80-82° C. for 90 minutes; the remaining 90 g of the second combination monomer, 2 g of hydroxyethyl acrylate, 70 g of ethyl acetate and 0.3 g of initiator BPO were mixed uniformly and added to the dropping funnel, and the mixture was added dropwise to the reaction system at a uniform speed within 90 minutes, maintaining the temperature at 80-82° C.; after the addition was completed, the mixture was kept warm for 270 minutes, cooled to below 50° C., and set aside.

[0032] (2) Add 20 g of GB-110 resin and 2 g of L-75 to the polyacrylate solution obtained in (2), and stir evenly to obtain a low surface energy special pressure-sensitive adhesive that can be coated on a machine.

[0033] (3) The pressure-sensitive adhesive obtained in (2) is coated on release paper, dried to form a pressure-sensitive adhesive layer (the thickness of the dry adhesive film is controlled to be 70 μm), and then transferred to a 12 μm PET substrate. In addition, another pressure-sensitive adhesive layer formed by drying is transferred to the other side of the PET substrate, and cured in a drying oven at 40° C. for 3 days to obtain the double-sided tape.

[0034] Example 2

[0035] Formula composition: First combination monomer: 35g lauryl acrylate, 60g behenyl acrylate; second combination monomer: 20g isooctyl acrylate, 80g butyl acrylate, 20g methyl acrylate; 6g acrylic acid, 3g hydroxyethyl acrylate, 230g ethyl acetate, 0.7g initiator BPO, 30g resin GA100A, 1.5g curing agent L-75.

[0036] Manufacturing process:

[0037] (1) 35 g of lauryl acrylate, 60 g of behenyl acrylate, 6 g of acrylic acid, 30 g of the second monomer combination and 150 g of ethyl acetate were added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, and heated to 80° C. 0.3 g of initiator BPO (dissolved in 10 g of ethyl acetate) was added to initiate the reaction, and the reaction was carried out at 80-82° C. for 90 minutes; the remaining 90 g of the second monomer combination, 3 g of hydroxyethyl acrylate, 70 g of ethyl acetate and 0.4 g of initiator BPO were mixed uniformly and added to the dropping funnel, and the mixture was added dropwise to the reaction system at a uniform speed over 90 minutes, maintaining the temperature at 80-82° C.; after the addition was completed, the mixture was kept warm for 270 minutes, cooled to below 50° C., and set aside.

[0038] (2) Add 30 g of GA100A resin and 1.5 g of L-75 to the polyacrylate solution obtained in (1), and stir evenly to obtain a low surface energy special pressure-sensitive adhesive that can be coated on a machine.

[0039] (3) The pressure-sensitive adhesive obtained in (2) is coated on release paper, dried to form a pressure-sensitive adhesive layer (the thickness of the dry adhesive film is controlled to be 70 μm), and then transferred to a 12 μm PET substrate. In addition, another pressure-sensitive adhesive layer formed by drying is transferred to the other side of the PET substrate, and cured in a drying oven at 40° C. for 3 days to obtain the double-sided tape.

[0040] Example 3

[0041] Formula composition: first combination monomer: 100g of behenyl acrylate; second combination monomer: 30g of isooctyl acrylate, 60g of butyl acrylate, 20g of methyl acrylate; 5g of acrylic acid, 2g of hydroxyethyl acrylate, 220g of ethyl acetate, 0.6g of initiator BPO, 30g of resin GB-110, and 2g of curing agent L-75.

[0042] Manufacturing process:

[0043] (1) 100 g of behenyl acrylate, 5 g of acrylic acid, 30 g of the second combination mixed monomer and 150 g of ethyl acetate were added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, and heated to 80° C., 0.3 g of initiator BPO (dissolved in 10 g of ethyl acetate) was added to initiate the reaction, and the reaction was carried out at 80-82° C. for 90 minutes; the remaining 80 g of the second combination monomer, 2 g of hydroxyethyl acrylate, 60 g of ethyl acetate and 0.3 g of initiator BPO were mixed uniformly and added to the dropping funnel, and the mixture was added dropwise to the reaction system at a uniform speed within 90 minutes, maintaining the temperature at 80-82° C.; after the addition was completed, the mixture was kept warm for 270 minutes, cooled to below 50° C., and set aside.

[0044] (2) Add 30 g of GB-110 resin and 2 g of L-75 to the polyacrylate solution obtained in (2), and stir evenly to obtain a low surface energy special pressure-sensitive adhesive that can be coated on a machine.

[0045] (3) The pressure-sensitive adhesive obtained in (2) is coated on release paper, dried to form a pressure-sensitive adhesive layer (the thickness of the dry adhesive film is controlled to be 70 μm), and then transferred to a 25 μm PET substrate. In addition, another pressure-sensitive adhesive layer formed by drying is transferred to the other side of the PET substrate, and cured in a drying oven at 40° C. for 3 days to obtain the double-sided tape.

[0046] Example 4

[0047] Formula composition: First combination monomer: hexadecyl acrylate 45g, octadecyl acrylate 45g; second combination monomer: isooctyl acrylate 50g, butyl acrylate 50g, methyl acrylate 25g; acrylic acid 6g, hydroxyethyl acrylate 2g, ethyl acetate 230g, initiator BPO 0.7g, resin GA100A25g, curing agent L-75 1.5g.

[0048] Manufacturing process:

[0049] (1) 45 g of hexadecyl acrylate, 45 g of octadecyl acrylate, 6 g of acrylic acid, 35 g of the second monomer combination and 150 g of ethyl acetate were added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, and heated to 80° C., 0.3 g of initiator BPO (dissolved in 10 g of ethyl acetate) was added to initiate the reaction, and the reaction was carried out at 80-82° C. for 90 minutes; the remaining 90 g of the second monomer combination, 2 g of hydroxyethyl acrylate, 70 g of ethyl acetate and 0.4 g of initiator BPO were mixed uniformly and added to the dropping funnel, and the mixture was added dropwise to the reaction system at a uniform speed within 90 minutes, maintaining the temperature at 80-82° C.; after the addition was completed, the mixture was kept warm for 300 minutes, cooled to below 50° C., and set aside.

[0050] (2) Add 25 g of GA100A resin and 1.5 g of L-75 to the polyacrylate solution obtained in (1), and stir evenly to obtain a low surface energy special pressure-sensitive adhesive that can be coated on a machine.

[0051] (3) The pressure-sensitive adhesive obtained in (2) is coated on release paper, dried to form a pressure-sensitive adhesive layer (the thickness of the dry adhesive film is controlled to be 70 μm), and then transferred to a 12 μm PET substrate. In addition, another pressure-sensitive adhesive layer formed by drying is transferred to the other side of the PET substrate, and cured in a drying oven at 40° C. for 3 days to obtain the double-sided tape.

[0052] Example 5

[0053] The formula is: second combination monomer: 60g of isooctyl acrylate, 110g of butyl acrylate; 8g of acrylic acid, 3g of hydroxyethyl acrylate, 15g of methyl acrylate, 200g of ethyl acetate, 0.6g of initiator BPO, 15g of resin GB-110, and 1.5g of curing agent L-75.

[0054] The manufacturing process is:

[0055] (1) 8 g of acrylic acid, 100 g of the second combination of mixed monomers and 120 g of ethyl acetate were added to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, and heated to 80° C. 0.3 g of initiator BPO (dissolved in 10 g of ethyl acetate) was added to initiate the reaction, and the reaction was carried out at 80-82° C. for 90 minutes; the remaining 85 g of the second combination of monomers, 3 g of hydroxyethyl acrylate, 70 g of ethyl acetate and 0.3 g of initiator BPO were mixed uniformly and added to the dropping funnel, and the mixture was added dropwise to the reaction system at a uniform speed over 90 minutes, maintaining the temperature at 80-82° C.; after the addition was completed, the mixture was kept warm for 270 minutes, cooled to below 50° C., and set aside.

[0056] (2) Add 15 g of GB-110 resin and 1.5 g of L-75 to the polyacrylate solution obtained in (2), and stir evenly to obtain a low surface energy special pressure-sensitive adhesive that can be coated on a machine.

[0057] (3) The pressure-sensitive adhesive obtained in (2) is coated on release paper, dried to form a pressure-sensitive adhesive layer (the thickness of the dry adhesive film is controlled to be 70 μm), and then transferred to a 12 μm PET substrate. In addition, another pressure-sensitive adhesive layer formed by drying is transferred to the other side of the PET substrate, and cured in a drying oven at 40° C. for 3 days to obtain the double-sided tape.

[0058] Performance Testing

[0059] The double-sided adhesive tapes prepared in each embodiment were subjected to a peeling force test. The specific test method is as follows. The measured results are shown in Table 1.

[0060] Test board PE board, PP board

[0061] Tape width 25mm

[0062] Pressure conditions: 2Kg, 600mm / min, rolling back and forth 2 times

[0063] Enhanced film 25um PET

[0064] Infiltration time RT 30min

[0065] Peeling speed 300mm / min

[0066] Test environment temperature 23±1℃, humidity (50±5%)RH

[0067] Test unit: N / 25cm.

[0068] Table 1 - Peel force properties of double-sided adhesive tapes prepared in Examples 1-5

[0069]

[0070] As can be seen from the above, the double-sided tapes prepared in Examples 1 to 4 within the scope of the present invention have higher bonding strength to low surface energy substrates, while the adhesive layer of the double-sided tape in Example 5 does not contain long-chain alkyl acrylate, and the bonding strength between the pressure-sensitive adhesive layer in the tape and the PP and PE substrates is relatively poor, resulting in a relatively low peeling force.

[0071] The above embodiments do not impose any limitation on the content of the composition of the present invention. Any slight modification, equivalent change and modification made to the above embodiments based on the technical essence or composition ingredients or content of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A double-sided adhesive tape for bonding low surface energy materials, characterized in that: The invention comprises a tape body, wherein the tape body is a four-layer structure, including a first adhesive layer, a body reinforcement layer, a second adhesive layer and a release protective layer; the first adhesive layer is above the body reinforcement layer; the body reinforcement layer is above the second adhesive layer; the second adhesive layer is above the release protective layer, wherein the first adhesive layer and the second adhesive layer are both acrylate pressure-sensitive adhesive layers, and the acrylate pressure-sensitive adhesive layers include the following raw material compositions in parts by weight: 100 parts of acrylate polymer solution, 5-20 parts of tackifying resin, and 0.2-1 part of cross-linking agent.

2. A double-sided adhesive tape for bonding low surface energy materials as claimed in claim 1, characterized in that: The acrylate pressure-sensitive adhesive layer is prepared by the following preparation steps: Step 1, preparing an acrylate polymer solution: adding a first monomer, a part of the second monomer, a part of the functional monomer and a solvent into a reaction container equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen inlet tube and a dropping funnel, stirring while heating to a certain temperature through N2, and then adding an initiator to react for 60-90 minutes; then using a dropping funnel to uniformly add the remaining second monomer, functional monomer, solvent and initiator mixture dropwise over a certain period of time, and after the dropwise addition is completed, heat preservation and reaction for 4-6 hours, thereby obtaining an acrylate polymer solution; Step 2, preparing a pressure-sensitive adhesive solution before coating: the acrylate polymer solution prepared in step 1, the tackifying resin, the cross-linking agent and the diluent are stirred and mixed uniformly to prepare a pressure-sensitive adhesive solution to be coated.

3. A double-sided adhesive tape for bonding low surface energy materials as claimed in claim 2, characterized in that: The acrylate polymer solution comprises the following components in parts by weight: 40-60 parts of a first monomer, 40-60 parts of a second monomer, 1-3 parts of acrylic acid, 0.5-2 parts of hydroxyethyl acrylate, 100-120 parts of ethyl acetate, and 0.1-0.3 parts of an initiator.

4. A double-sided adhesive tape for bonding low surface energy materials as claimed in claim 3, characterized in that: The first monomer is one or more of lauryl acrylate, hexadecyl acrylate, octadecyl acrylate and behenyl acrylate; The second monomer is calculated based on 100 parts in total and is composed of 10-40 parts of isooctyl acrylate, 20-40 parts of butyl acrylate and 20-40 parts of methyl acrylate; The solvent is one or more of ethyl acetate, butyl acetate, n-hexane and mixed solvents thereof; The initiator is one or more of benzoyl peroxide, azobisisobutyronitrile and azobisisoheptanenitrile.

5. A double-sided adhesive tape for bonding low surface energy materials as claimed in claim 1, characterized in that: The cross-linking agent is one or more of an isocyanate cross-linking agent, an epoxy cross-linking agent, and a metal salt cross-linking agent; The tackifying resin is one or more of terpene and its derivative resins and rosin and its derivative resins; the tackifying resin has a softening point of 90-130° C. and an acid value of ≤30 (mgKOH / g).

6. A double-sided adhesive tape for bonding low surface energy materials as claimed in claim 1, characterized in that: The main reinforcement layer is made of tissue paper or PET material, wherein the material thickness is 5 μm-100 μm.

7. A double-sided adhesive tape for bonding low surface energy materials as claimed in claim 1, characterized in that: The thickness of the first adhesive layer is 20-100 μm, and the thickness of the second adhesive layer is 20-100 μm.

8. A method for preparing a double-sided adhesive tape for bonding low surface energy materials according to any one of claims 1 to 7, characterized in that: The method comprises the following preparation steps: Step 1: fix the release protective layer on a special coating device, apply a certain amount of special pressure-sensitive adhesive for low surface energy materials as the second adhesive layer, dry to form a pressure-sensitive adhesive layer, transfer it to the main reinforcement layer, and roll it up with the main reinforcement layer for standby use; Step 2: Unroll the coiled material of step 1 on a special coating device, apply a certain amount of special pressure-sensitive adhesive of low surface energy material on the other side of the main reinforcement layer as the first adhesive layer, cure it in a drying room at 40°C for 3 days, and then roll it up to obtain a double-sided tape.

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