Water-based neutral adhesive remover and preparation method thereof

Abstract

The invention relates to the technical field of degumming agents, in particular to a water-based neutral degumming agent and a preparation method thereof.The water-based neutral degumming agent is prepared from, by weight, 13%-17% of methyl salicylate, 27%-33% of glycol ether, 3%-7% of polyvinylpyrrolidone, 3%-5% of a softening agent, 1.1%-1.4% of a pH regulator, 1%-5% of liquid paraffin and the balance water; the device has the advantages that the OCA optical cement can be effectively removed, and the black oil is not damaged.

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 made by making optical acrylic adhesive without a substrate, and then a layer of release film is attached to the upper and lower bottom layers. It is a double-sided laminating tape without a substrate material. Due to the excellent properties of OCA optical adhesive such as high clarity, high light transmittance, high adhesion, high weather resistance, water resistance, high temperature resistance, and UV resistance, OCA optical adhesive is being used more and more widely. Among them, in the application of mobile phone cover lamination, there is a high probability that defective products need to be reworked. During rework, the OCA optical adhesive needs to be removed by 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 the cost; if the degumming agent has a weak removal ability, it is easy to cause residues and affect the subsequent processes. 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 degumming agent, which adopts the following technical solution: 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.

[0005] By adopting the above technical solution, polyvinyl pyrrolidone has a similar effect as a penetrant. As a surfactant and a polymer, the lipophilic group in the molecule of polyvinyl pyrrolidone can wrap methyl salicylate well. 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 being dissolved in water, it can make the distribution of methyl salicylate in water more uniform, which is conducive to the uniformity of 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 short.

[0006] Preferably, the molecular weight of the polyvinyl pyrrolidone is 3500-5500.

[0007] By adopting the above technical solution, as the molecular weight of polyvinyl pyrrolidone gradually increases, the time required for 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, which affects its release and function. Therefore, the molecular weight of polyvinyl pyrrolidone should not be too large.

[0008] Preferably, the weight percentage of the added polyvinyl pyrrolidone is 5%.

[0009] By adopting the above technical solution, when the added amount of polyvinyl pyrrolidone is 5kg, 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.

[0010] 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.

[0011] By adopting the above technical scheme, the amino-terminated hyperbranched polyamide is used as a hyperbranched polymer, and its solubility in water is very strong, and its viscosity is very low, and the molecule contains more functional amino groups. The inventors designed experiments and applied it to the degumming agent, and found that it can cooperate with triethanolamine to play a synergistic effect, accelerate the softening of OCA optical glue, effectively reduce the toughness of OCA optical glue, and remove OCA optical glue faster, greatly shortening the degumming time. In addition, the amino-terminated hyperbranched polyamide is used as a polymer, and its volatility is extremely low compared with triethanolamine. Adding the amino-terminated hyperbranched polyamide can effectively improve the safety of degumming and reduce environmental pollution.

[0012] Preferably, the molecular weight of the amino-terminated hyperbranched polyamide is 800-1000.

[0013] By adopting the above technical scheme, 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 the shortest.

[0014] Preferably, the weight ratio of the amino-terminated hyperbranched polyamide to the triethanolamine is 2:1.

[0015] 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, but 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, and the degumming time can reach 3-4 minutes, and the black oil is not damaged and no residual glue is left.

[0016] Preferably, the molecular structure of the pH regulator contains a benzene ring, a phenolic hydroxyl group and a carboxyl group.

[0017] By adopting the above technical solution, the pH regulator with different structures has a certain influence on the degumming effect of the degumming agent. 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 adjusting pH, it can also use the benzene ring, phenolic hydroxyl and other groups in the molecular structure to participate in the swelling effect of methyl salicylate on OCA optical glue, thereby reducing the degumming time.

[0018] Preferably, the pH regulator is one or more of caffeic acid, ferulic acid, p-coumaric acid, syringic acid and vanillic acid.

[0019] In a second aspect, the present application provides a method that adopts the following technical solution: A method for preparing a water-based neutral degumming agent comprises the following steps: S1. Add polyvinyl pyrrolidone and softener into water and stir until dissolved to obtain component A; S2, mixing methyl salicylate and ethylene glycol ethyl ether uniformly 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 degumming agent.

[0020] By adopting the above technical solution, the present application does not require additional improvements to the equipment, the 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.

[0021] In summary, the present application includes at least one of the following beneficial technical effects: 1. Polyvinyl pyrrolidone plays a role similar to that of a penetrant. As a surfactant and a polymer, the lipophilic group in its molecule can wrap methyl salicylate well. 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 being dissolved in water, it can make the distribution of methyl salicylate in water more uniform, which helps the uniformity of 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 short.

[0022] 2. As a hyperbranched polymer, amino-terminated hyperbranched polyamide 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 the degumming agent, and found that it can cooperate with triethanolamine to play a synergistic role, accelerate the softening of OCA optical glue, effectively reduce the toughness of OCA optical glue, and remove OCA optical glue faster, greatly shortening the degumming time. Moreover, as a polymer, amino-terminated hyperbranched polyamide has extremely low volatility compared with triethanolamine. Adding amino-terminated hyperbranched polyamide can effectively improve the safety of degumming and reduce environmental pollution.

[0023] 3. The residual glue content of the water-based neutral degumming agent prepared in this 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 below 21-22 minutes, and can be as low as 2-3 minutes; it greatly shortens the degumming time, improves work efficiency, and saves time costs. DETAILED DESCRIPTION

[0024] The present application is further described in detail below in conjunction with the specific contents.

[0025] raw material 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. Example

[0026] Example 1 A water-based neutral degumming agent, the raw materials and the amounts of the raw materials are shown in Table 1, and the preparation method is as follows: S1. Add polyvinyl pyrrolidone and triethanolamine into water and stir until dissolved to obtain component A; S2, mixing methyl salicylate and ethylene glycol ethyl ether uniformly to obtain component B; 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 degumming agent.

[0027] Among them, the softener is triethanolamine; the pH adjuster is caffeic acid; the average molecular weight of polyvinyl pyrrolidone is 3500, and the corresponding product specification is K12.

[0028] Table 1 Raw materials and amounts of raw materials in Example 1 (kg) Methyl salicylate 15 Ethylene glycol ether 30 Polyvinylpyrrolidone 5 Softener 4 pH Adjusters 1.2 Liquid paraffin 3 water Top up to 100 Example 2 A water-based neutral degumming agent, which 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 adjuster added is 1.3 kg, and the remaining steps are the same as Example 1.

[0029] Example 3 A water-based neutral degumming agent, which 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 adjuster added is 1.4 kg, and the remaining steps are the same as Example 1.

[0030] Example 4 A water-based neutral degumming agent, which 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.

[0031] Example 5 A water-based neutral degumming agent is different from Example 1 in that the amount of polyvinyl pyrrolidone added is 7 kg, the amount of pH adjuster added is 1.1 kg, and the remaining steps are the same as Example 1.

[0032] Example 6 A water-based neutral degumming agent, which is different from Example 1 in that its softener is a mixture of terminal amino hyperbranched polyamide and triethanolamine, the mass ratio of terminal amino hyperbranched polyamide and triethanolamine is 1:1, the molecular weight range of terminal amino hyperbranched polyamide is 350-370, and the remaining steps are the same as Example 1.

[0033] Example 7 A water-based neutral degumming agent, which is different from Example 6 in that the molecular weight range of its amino-terminated hyperbranched polyamide is 800-1000, and the remaining steps are the same as Example 6.

[0034] Example 8 A water-based neutral degumming agent, which is different from Example 6 in that the molecular weight range of its amino-terminated hyperbranched polyamide is 1900-2200, and the remaining steps are the same as Example 6.

[0035] Example 9 A water-based neutral degumming agent, which is different from Example 7 in that the mass ratio of the terminal amino hyperbranched polyamide and triethanolamine in the softener is 2:1, and the remaining steps are the same as Example 7.

[0036] Example 10 A water-based neutral degumming agent, which is different from Example 7 in that the mass ratio of the terminal amino hyperbranched polyamide and triethanolamine in the softener is 3:1, and the remaining steps are the same as those in Example 7.

[0037] Embodiment 11 A water-based neutral degumming agent, which is different from Example 9 in that its pH regulator is an equal mass of syringic acid, and the remaining steps are the same as Example 9.

[0038] Comparative Example Comparative Example 1 A water-based neutral degumming agent, which is different from Example 1 in that its pH regulator is 0.3 kg of citric acid, and the remaining steps are the same as Example 1.

[0039] Comparative Example 2 A water-based neutral degumming agent, which is different from Example 1 in that its pH regulator is 1.4 kg of benzoic acid, and the remaining steps are the same as those of Example 1.

[0040] Comparative Example 3 A water-based neutral degumming agent, which 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 those of Example 1.

[0041] Performance testing Detection method / test method Aqueous neutral degumming 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.

[0042] 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 time required for debonding were recorded.

[0043] Table 2 Test results of Examples 1-11 and Comparative Examples 1-3 The residual glue is usually at the corners, where the contact area between the glue and the cover plate is large and the thickness is thick. It is difficult to completely remove the glue when the removal ability of the glue remover is low.

[0044] 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 aqueous 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 the time cost is saved.

[0045] Polyvinyl pyrrolidone has a similar effect as a penetrant here. Polyvinyl pyrrolidone is used as a surfactant and as a polymer. The lipophilic group in its molecule can wrap methyl salicylate well. The hydrophilic group has a strong polarity. Under the synergistic effect with ethylene glycol ether, it can quickly penetrate into the interior of the OCA optical glue, so that methyl salicylate can play a role quickly. 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 is helpful for the uniformity of the aqueous neutral degumming agent. It can also be seen from the test data of Example 1 and Comparative Example 3 that compared with LF305, the addition of polyvinyl pyrrolidone can remove glue more thoroughly and can effectively shorten the degumming time. Combined with Examples 2-3, as the molecular weight of polyvinyl pyrrolidone gradually increases, the time required for its degumming tends to increase, and when its molecular weight increases to 10100, it cannot completely remove the OCA optical glue, and the residual glue content reaches 3.2%. It is considered that due to the large molecular weight of polyvinyl pyrrolidone, 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. In combination with Examples 4-5, when the addition amount of polyvinyl pyrrolidone is 5kg, the degumming effect is better.

[0046] As a hyperbranched polymer, amino-terminated hyperbranched polyamide has strong solubility in water, low viscosity, and contains more functional amino groups in the molecule. The inventor applied it to the degumming agent by designing experiments and found that it can cooperate with triethanolamine to play 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 the best, and the degumming time is the shortest. In combination with Examples 9-10, as the addition ratio of the amino-terminated hyperbranched polyamide increases, the degumming ability of the degumming agent becomes stronger and stronger, and the degumming time can reach 2-3min, but 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 a better addition ratio, and the degumming time can reach 3-4min, and the black oil is not damaged, and there is no residual glue. In addition, as a polymer, the amino-terminated hyperbranched polyamide has extremely low volatility compared with triethanolamine. Adding the amino-terminated hyperbranched polyamide can effectively improve the safety of degumming and reduce environmental pollution.

[0047] It can be seen from the test data of Example 9 and Example 11 that when the pH adjusting agent 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 adjusting agents of different structures are used, and the degumming effect of the degumming agent has a certain influence. 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 is that in addition to playing the role of regulating pH, it can also utilize the benzene ring, phenolic hydroxyl groups in the molecular structure to participate in the swelling effect of methyl salicylate on OCA optical glue, thereby reducing the degumming time.

[0048] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A water-based neutral degumming agent, characterized in that: The invention 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.

2. The aqueous neutral adhesive remover according to claim 1, characterized in that: The molecular weight of the polyvinyl pyrrolidone is 3500-5500.

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

4. The aqueous neutral adhesive remover according to claim 1, characterized in that: 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.

5. The aqueous neutral adhesive remover according to claim 4, characterized in that: The molecular weight of the amino-terminated hyperbranched polyamide is 800-1000.

6. The aqueous neutral adhesive remover according to claim 5, characterized in that: The weight ratio of the amino-terminated hyperbranched polyamide to the triethanolamine is 2:

1.

7. The aqueous neutral adhesive remover according to claim 1, characterized in that: The molecular structure of the pH regulator contains a benzene ring, a phenolic hydroxyl group and a carboxyl group.

8. The aqueous neutral adhesive remover according to claim 7, characterized in that: The pH regulator is one or more of caffeic acid, ferulic acid, p-coumaric acid, syringic acid and vanillic acid.

9. A method for preparing the aqueous neutral degumming agent according to any one of claims 1 to 8, characterized in that: It includes the following steps: S1. Add polyvinyl pyrrolidone and softener into water and stir until dissolved to obtain component A; S2, mixing methyl salicylate and ethylene glycol ethyl ether uniformly 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 degumming agent.

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