An aqueous neutral adhesive remover and its preparation method

Abstract

The present application relates to the technical field of adhesive removers, and in particular to a water-based neutral adhesive remover and a preparation method thereof. The water-based neutral adhesive remover comprises the following raw materials in percentage by weight: 13-17% methyl salicylate, 27-33% ethylene glycol ethyl ether, 3-7% polyvinyl pyrrolidone, 3-5% softener, 1.1-1.4% pH adjuster, 1-5% liquid paraffin, and the balance is water; the water-based neutral adhesive remover has the advantages of being able to effectively remove OCA optical adhesive without damaging black oil.

Description

Technical Field

[0001] The present application relates to the technical field of adhesive removers, and in particular to a water-based neutral adhesive remover and a preparation method thereof. Background Art

[0002] OCA optical adhesive is one of the important raw materials for touch screens. It is a double-sided adhesive tape made by making optical acrylic adhesive without a substrate, and then laminating a layer of release film on the upper and lower bottom layers. OCA optical adhesive is increasingly widely used due to its excellent properties such as high clarity, high light transmittance, high adhesion, high weather resistance, water resistance, high temperature resistance, and UV resistance. Among them, in the application of mobile phone cover lamination, there is a high probability that defective products will need to be reworked. During rework, the OCA optical adhesive needs to be removed with a degumming agent, but there is also black oil used for decoration on the cover. If the degumming agent is highly corrosive to the black oil, it will increase the process and increase costs; if the degumming agent has weak cleaning ability, it is easy to cause residue, affecting the subsequent process. Summary of the Invention

[0003] In order to effectively remove OCA optical glue without damaging the black oil, the present application provides a water-based neutral glue remover and a preparation method thereof.

[0004] In the first aspect, the present application provides a water-based neutral adhesive remover, which adopts the following technical solution:

[0005] A water-based neutral adhesive remover comprises the following raw materials in percentage by weight: 13-17% of methyl salicylate, 27-33% of ethylene glycol ethyl ether, 3-7% of polyvinyl pyrrolidone, 3-5% of softener, 1.1-1.4% of pH regulator, 1-5% of liquid paraffin, and the balance is water.

[0006] By adopting the above technical solution, polyvinyl pyrrolidone plays a role similar to that of a penetrant. As a surfactant and a polymer, the lipophilic group in the molecule of polyvinyl pyrrolidone can better wrap methyl salicylate. The hydrophilic group has a strong polarity. Under the synergistic effect with ethylene glycol ethyl ether, it can quickly penetrate into the interior of the OCA optical adhesive, allowing methyl salicylate to take effect quickly. Polyvinyl pyrrolidone also has a strong solubilizing effect. After dissolving in water, it can make the distribution of methyl salicylate in the water more uniform, which helps to uniformize the water-based neutral degumming agent. Working together with other substances in the system, the degumming agent can completely remove the glue and the degumming time is relatively short.

[0007] Preferably, the molecular weight of the polyvinyl pyrrolidone is 3500-5500.

[0008] By adopting the above technical solution, as the molecular weight of polyvinyl pyrrolidone gradually increases, the time required for its degumming tends to increase. When the molecular weight is within this range, the degumming time is shorter. This is because the molecular weight of polyvinyl pyrrolidone is relatively large, and its encapsulation of methyl salicylate is too strong, affecting its release and function. Therefore, the molecular weight of polyvinyl pyrrolidone should not be too large.

[0009] Preferably, the weight percentage of the added polyvinyl pyrrolidone is 5%.

[0010] By adopting the above technical solution, when the added amount of polyvinyl pyrrolidone is 5 kg, the degumming effect is better. When the added amount is too large, its encapsulation of methyl salicylate is also stronger, which is not conducive to the release of methyl salicylate.

[0011] Preferably, the softener is a mixture of amino-terminated hyperbranched polyamide and triethanolamine, and the weight ratio of amino-terminated hyperbranched polyamide to triethanolamine is (1-3):1.

[0012] By adopting the above technical solution, the amino-terminated hyperbranched polyamide is used as a hyperbranched polymer, which has strong solubility in water and low viscosity, and contains more functional amino groups in the molecule. The inventor designed an experiment and applied it to a degumming agent and found that it can cooperate with triethanolamine to achieve a synergistic effect, accelerate the softening of OCA optical adhesive, effectively reduce the toughness of OCA optical adhesive, and remove OCA optical adhesive faster, greatly shortening the degumming time. In addition, the amino-terminated hyperbranched polyamide is a polymer with extremely low volatility compared to triethanolamine. Adding the amino-terminated hyperbranched polyamide can effectively improve the safety of degumming and reduce environmental pollution.

[0013] Preferably, the molecular weight of the amino-terminated hyperbranched polyamide is 800-1000.

[0014] By adopting the above technical solution, when the molecular weight of the amino-terminated hyperbranched polyamide is in the range of 800-1000, the synergistic effect between the amino-terminated hyperbranched polyamide and triethanolamine is optimal, and the degumming time is shortest.

[0015] Preferably, the weight ratio of the amino-terminated hyperbranched polyamide to the triethanolamine is 2:1.

[0016] By adopting the above technical solution, as the addition ratio of terminal amino hyperbranched polyamide increases, the degumming ability of the degumming agent becomes stronger and stronger. However, when the addition ratio reaches 3:1, the degumming ability is too strong and the black oil on the cover plate is slightly corroded. Therefore, the addition ratio is 2:1, which is the optimal addition ratio. The degumming time can reach 3-4 minutes, and the black oil is not damaged and no residual glue is left.

[0017] Preferably, the molecular structure of the pH regulator contains a benzene ring, a phenolic hydroxyl group and a carboxyl group.

[0018] By adopting the above technical solution and using pH adjusters with different structures, the debonding effect of the debonding agent was significantly affected. Experiments found that carboxylic acids containing phenolic hydroxyl groups in their molecular structure were more effective in debonding. Analysis suggests that in addition to regulating pH, the benzene rings and phenolic hydroxyl groups in the molecular structure can also participate in the swelling effect of methyl salicylate on OCA optical adhesive, thereby reducing debonding time.

[0019] Preferably, the pH regulator is one or more of caffeic acid, ferulic acid, p-coumaric acid, syringic acid and vanillic acid.

[0020] In a second aspect, the present application provides a method that employs the following technical solutions:

[0021] A method for preparing a water-based neutral adhesive remover comprises the following steps:

[0022] S1. Add polyvinyl pyrrolidone and softener to water and stir until dissolved to obtain component A;

[0023] S2. Evenly mix methyl salicylate and ethylene glycol ethyl ether to obtain component B;

[0024] S3. Add component B to component A, stir thoroughly, then add a pH adjuster, continue stirring, and finally add liquid paraffin to obtain a water-based neutral debonding agent.

[0025] By adopting the above technical solution, the present application does not require additional improvements to the equipment, its preparation process is relatively conventional, the parameter requirements for the preparation process are relatively broad, the qualified rate of the prepared products is high, and it is suitable for large-scale production.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. Polyvinylpyrrolidone acts like a penetrant. As a surfactant and polymer, the lipophilic group in its molecule can effectively encapsulate methyl salicylate. The hydrophilic group has strong polarity. Working synergistically with ethylene glycol ethyl ether, it can quickly penetrate into the interior of the OCA optical adhesive, allowing methyl salicylate to take effect quickly. Polyvinylpyrrolidone also has a strong solubilizing effect. Once dissolved in water, it can make the methyl salicylate more evenly distributed in the water, contributing to the uniformity of the water-based neutral adhesive remover. Working together with other substances in the system, the adhesive remover can completely remove the adhesive and remove it in a short time.

[0028] 2. As a hyperbranched polymer, amino-terminated hyperbranched polyamide has strong solubility in water and low viscosity, and contains a large number of functional amino groups in the molecule. The inventor designed an experiment and applied it to a degumming agent and found that it can cooperate with triethanolamine to achieve a synergistic effect, accelerate the softening of OCA optical adhesive, effectively reduce the toughness of OCA optical adhesive, and remove OCA optical adhesive more quickly, greatly shortening the degumming time. In addition, as a polymer, amino-terminated hyperbranched polyamide has extremely low volatility compared to triethanolamine. Adding amino-terminated hyperbranched polyamide can effectively improve the safety of degumming and reduce environmental pollution.

[0029] 3. The residual glue content of the water-based neutral glue remover prepared in this application is 3.2% or less, and it has basically no corrosion to the black oil on the cover plate. The glue removal time is basically less than 21-22 minutes, and can be as low as 2-3 minutes; it greatly shortens the glue removal time, improves work efficiency, and saves time costs. DETAILED DESCRIPTION

[0030] The following is a further detailed description of this application in conjunction with the specific content.

[0031] raw material

[0032] The raw materials used in the examples of the present application were all purchased from commercial sources, and the raw materials used were all industrial-grade products, and the water was deionized water.

[0033] Example

[0034] Example 1

[0035] A water-based neutral desmear agent, the raw materials and the amounts of the raw materials are shown in Table 1, and the preparation method is as follows:

[0036] S1. Add polyvinyl pyrrolidone and triethanolamine to water and stir until dissolved to obtain component A;

[0037] S2. Evenly mix methyl salicylate and ethylene glycol ethyl ether to obtain component B;

[0038] S3. Add component B to component A, stir for 1 hour, then add citric acid, continue stirring for 20 minutes, and finally add liquid paraffin to obtain a water-based neutral debonding agent.

[0039] Among them, the softener is triethanolamine; the pH adjuster is caffeic acid; the average molecular weight of polyvinylpyrrolidone is 3500, and the corresponding product specification is K12.

[0040] Table 1 Raw materials and amounts of raw materials used in Example 1 (kg)

[0041] Methyl salicylate 15 Ethylene glycol ethyl ether 30 Polyvinylpyrrolidone 5 softener 4 pH adjusters 1.2 liquid paraffin 3 water Replenish to 100

[0042] Example 2

[0043] A water-based neutral debonding agent is different from Example 1 in that the average molecular weight of polyvinyl pyrrolidone is 5500, the corresponding product specification is K15, the amount of pH regulator added is 1.3 kg, and the remaining steps are the same as Example 1.

[0044] Example 3

[0045] A water-based neutral degumming agent is different from Example 1 in that the average molecular weight of polyvinyl pyrrolidone is 10100, the corresponding product specification is K17, the amount of pH regulator added is 1.4 kg, and the remaining steps are the same as Example 1.

[0046] Example 4

[0047] A water-based neutral debonding agent is different from Example 1 in that the amount of polyvinyl pyrrolidone added is 3 kg, the amount of pH adjuster added is 1.3 kg, and the remaining steps are the same as Example 1.

[0048] Example 5

[0049] A water-based neutral debonding agent is different from Example 1 in that the amount of polyvinyl pyrrolidone added is 7 kg, the amount of pH regulator added is 1.1 kg, and the remaining steps are the same as Example 1.

[0050] Example 6

[0051] A water-based neutral debonding agent, which differs from Example 1 in that its softener is a mixture of amino-terminated hyperbranched polyamide and triethanolamine, the mass ratio of amino-terminated hyperbranched polyamide to triethanolamine is 1:1, the molecular weight range of amino-terminated hyperbranched polyamide is 350-370, and the remaining steps are the same as Example 1.

[0052] Example 7

[0053] A water-based neutral debonding agent is different from Example 6 in that the molecular weight of its amino-terminated hyperbranched polyamide is in the range of 800-1000, and the remaining steps are the same as Example 6.

[0054] Example 8

[0055] A water-based neutral debonding agent is different from Example 6 in that the molecular weight of the amino-terminated hyperbranched polyamide is in the range of 1900-2200, and the remaining steps are the same as Example 6.

[0056] Example 9

[0057] A water-based neutral debonding agent is different from Example 7 in that the mass ratio of the amino-terminated hyperbranched polyamide and triethanolamine in the softener is 2:1, and the remaining steps are the same as Example 7.

[0058] Example 10

[0059] A water-based neutral degumming agent is different from Example 7 in that the mass ratio of the amino-terminated hyperbranched polyamide and triethanolamine in the softener is 3:1, and the remaining steps are the same as Example 7.

[0060] Example 11

[0061] A water-based neutral adhesive remover is different from Example 9 in that its pH adjuster is syringic acid of equal mass, and the remaining steps are the same as Example 9.

[0062] Comparative Example

[0063] Comparative Example 1

[0064] A water-based neutral adhesive remover is different from Example 1 in that its pH adjuster is 0.3 kg of citric acid, and the remaining steps are the same as Example 1.

[0065] Comparative Example 2

[0066] A water-based neutral adhesive remover is different from Example 1 in that its pH adjuster is 1.4 kg of benzoic acid, and the remaining steps are the same as Example 1.

[0067] Comparative Example 3

[0068] A water-based neutral adhesive remover is different from Example 1 in that the polyvinyl pyrrolidone is replaced by LF305 of equal mass, and the remaining steps are the same as Example 1.

[0069] Performance testing

[0070] Detection method / test method

[0071] Water-based neutral debonding agents were prepared according to the preparation methods of Examples 1-11 and Comparative Examples 1-3, and then tested according to the following test method. The test results are shown in Table 2.

[0072] The OCA optical adhesive on the mobile phone cover was debonded using the aqueous neutral adhesive remover of Examples 1-11 and Comparative Examples 1-3, and the residual adhesive content, black oil corrosivity, and debonding time were recorded.

[0073] Table 2 Test results of Examples 1-11 and Comparative Examples 1-3

[0074]

[0075]

[0076] The residual glue is usually at the corners, where the contact area between the glue and the cover is large and the thickness is relatively thick. It is difficult to completely remove the glue when the removal ability of the glue remover is low.

[0077] It can be seen from Examples 1-11 and Comparative Examples 1-3, as well as the test data in Table 2, that the residual glue content of the water-based neutral degumming agent prepared in the present application is 3.2% or less, and it has basically no corrosion to the black oil on the cover plate. The degumming time is basically less than 21-22 minutes, and can be as low as 2-3 minutes; the degumming time is greatly shortened, the work efficiency is improved, and time costs are saved.

[0078] Polyvinyl pyrrolidone has a similar effect as a penetrant here. As a surfactant and a polymer, the lipophilic group in its molecule can better wrap methyl salicylate, and the hydrophilic group has a strong polarity. Under the synergistic effect with ethylene glycol ethyl ether, it can quickly penetrate into the interior of the OCA optical adhesive, allowing methyl salicylate to quickly take effect. Polyvinyl pyrrolidone also has a strong solubilizing effect. After being dissolved in water, it can make the distribution of methyl salicylate in water more uniform, which helps to improve the uniformity of the water-based neutral adhesive remover. It can also be seen from the test data of Example 1 and Comparative Example 3 that compared to LF305, the addition of polyvinyl pyrrolidone can remove the adhesive more thoroughly and can effectively shorten the adhesive removal time. In combination with Examples 2-3, as the molecular weight of polyvinyl pyrrolidone gradually increases, the time required for its adhesive removal tends to increase, and when its molecular weight increases to 10100, it cannot completely remove the OCA optical adhesive, and the residual adhesive content reaches 3.2%. Considering that due to the large molecular weight of polyvinyl pyrrolidone, its wrapping property for methyl salicylate is too strong, affecting its release and function, therefore, the molecular weight of polyvinyl pyrrolidone should not be too large. In combination with Examples 4-5, when the amount of polyvinyl pyrrolidone added is 5kg, the degumming effect is better.

[0079] As a hyperbranched polymer, amino-terminated hyperbranched polyamide has strong solubility in water and very low viscosity, and contains more functional amino groups in the molecule. The inventor applied it to the degumming agent by designing an experiment and found that it can cooperate with triethanolamine to achieve a synergistic effect, accelerate the softening of OCA optical adhesive, effectively reduce the toughness of OCA optical adhesive, remove OCA optical adhesive faster, and greatly shorten the degumming time. It can be verified by Example 1 and Example 6. In conjunction with Examples 7-8, when the molecular weight range of amino-terminated hyperbranched polyamide is 800-1000, the synergy between it and triethanolamine is best, and the degumming time is the shortest. In conjunction with Examples 9-10, as the addition ratio of amino-terminated hyperbranched polyamide increases, the degumming ability of the degumming agent becomes stronger, and the degumming time can reach 2-3 minutes. However, when the addition ratio reaches 3:1, the degumming ability is too strong, and the black oil on the cover plate is slightly corrosive. Therefore, the addition ratio of 2:1 is the optimal addition ratio, and the degumming time can reach 3-4 minutes without damaging the black oil and leaving no residual glue. In addition, as a polymer, amino-terminated hyperbranched polyamide has extremely low volatility compared to triethanolamine. Adding amino-terminated hyperbranched polyamide can effectively improve the safety of degumming and reduce environmental pollution.

[0080] It can be seen from the test data of Example 9 and Example 11 that when the pH regulator of the present application is syringic acid, the technical effect of the present application can also be achieved. Combined with the test data molecules of Comparative Examples 1-2, the pH regulators of different structures are used, and the degumming effect of the degumming agent is affected to a certain extent. The experiment found that the degumming effect is better when a carboxylic acid containing a phenolic hydroxyl group in the molecular structure is used. The analysis shows that in addition to playing the role of regulating pH, it can also utilize the benzene ring, phenolic hydroxyl group and other groups in the molecular structure to participate in the swelling effect of methyl salicylate on OCA optical adhesive, thereby reducing the degumming time.

[0081] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A water-based neutral glue remover, characterized in that: The method comprises the following raw materials in percentage by weight: 13-17% methyl salicylate, 27-33% ethylene glycol ethyl ether, 3-7% polyvinyl pyrrolidone, 3-5% softener, 1.1-1.4% pH regulator, 1-5% liquid paraffin, and the balance is water; The molecular weight of the polyvinyl pyrrolidone is 3500-5500; The softener is a mixture of amino-terminated hyperbranched polyamide and triethanolamine, and the weight ratio of amino-terminated hyperbranched polyamide to triethanolamine is (1-3):1; The pH regulator is one or more of caffeic acid, ferulic acid, p-coumaric acid, syringic acid and vanillic acid.

2. The water-based neutral adhesive remover according to claim 1, characterized in that: The weight percentage of the added polyvinyl pyrrolidone is 5%.

3. The water-based neutral adhesive remover according to claim 1, characterized in that: The molecular weight of the amino-terminated hyperbranched polyamide is 800-1000.

4. The aqueous neutral adhesive remover according to claim 3, characterized in that: The weight ratio of the amino-terminated hyperbranched polyamide to the triethanolamine is 2:

1.

5. A method for preparing the water-based neutral adhesive remover according to any one of claims 1 to 4, characterized in that: It includes the following steps: S1. Add polyvinyl pyrrolidone and softener to water and stir until dissolved to obtain component A; S2. Evenly mix methyl salicylate and ethylene glycol ethyl ether to obtain component B; S3. Add component B to component A, stir thoroughly, then add a pH adjuster, continue stirring, and finally add liquid paraffin to obtain a water-based neutral debonding agent.

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