Protective film for protecting glass surface as well as preparation method and application of protective film

Abstract

The invention relates to a protective film for protecting the surface of glass and a preparation method and application thereof, the protective film comprises a base material layer, an adhesive layer and a release layer which are arranged in sequence, and the adhesive layer comprises the following components in parts by weight: 100 parts of polyurethane adhesive; 5-15 parts of a modified antioxidant; 10-15 parts of a curing agent; 5-10 parts of a solvent; the modified antioxidant comprises an antioxidant and a neutralizer, the antioxidant has a tert-butyl group, a benzene ring group and an aniline group, the neutralizer is an acidic substance, the weight ratio of the antioxidant to the neutralizer is 100: (15-30), and the protective film is good in adhesive force.

Description

Technical Field

[0001] The invention relates to the technical field of adhesive tapes, and in particular to a protective film for protecting a glass surface, a preparation method thereof and an application thereof. Background Art

[0002] A protective film is a film-like material that has a protective function for other materials. It is attached to the surface of the protected object to prevent the object from being scratched or corroded by dust, pollutants, and harmful gases during production, processing, and transportation, so that the surface of the object remains in its original state. For example, a protective film is attached to the surface of the glass, such as the "A PU Glue Touch Screen Protective Film" disclosed in the Chinese utility model patent with patent number CN202120756471.0 (publication number CN215203883U). The PU Glue Touch Screen Protective Film includes: a PET transparent film, the thickness of the PET transparent film is set to 50μm; an adhesive layer, the adhesive layer is set to a polyurethane adhesive, the adhesive layer is adhered to the lower surface of the PET transparent film, and the thickness of the adhesive layer is set to 58μm; a PET release film, the PET release film is adhered to the lower surface of the adhesive layer, and the thickness of the PET release film is set to 50μm. The PU adhesive touch screen protective film has an adhesive layer with an outgassing property of 0.3-1s. It has excellent outgassing performance and good high temperature resistance. It is widely used in the manufacturing process and shipment protection of optical glass and electronic components.

[0003] In some processing fields, when using glass, it is necessary to treat it at high temperature (150-260℃), and at the same time, the surface performance of the glass needs to be protected from being affected during this process. When the protective film is peeled off from the glass surface, there should be no marks on the glass surface. At a temperature of about 120℃, the bonding ability and strength of acrylic glue decline, which causes the protective film to fall off and residual glue. When the protective film is peeled off, part of the glue layer remains on the glass surface, which needs to be manually processed, affecting the production process.

[0004] In order to reduce the contamination of the protective film on the glass surface and ensure the stability of the surface tension of the glass surface, the pressure-sensitive adhesive used is required to have high cohesive strength and weather resistance, and the adhesive layer must have sufficient resistance to thermal creep and moisture creep. Summary of the invention

[0005] The first technical problem to be solved by the present invention is to provide a protective film with strong adhesive force for protecting the glass surface in view of the above-mentioned prior art.

[0006] The second technical problem to be solved by the present invention is to provide a method for preparing the protective film for protecting the glass surface according to the above-mentioned prior art.

[0007] The third technical problem to be solved by the present invention is to provide an application of the protective film for protecting the glass surface in view of the above-mentioned prior art.

[0008] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a protective film for protecting the surface of a glass, comprising a substrate layer, an adhesive layer and a release layer arranged in sequence, characterized in that the adhesive layer comprises the following components in parts by weight:

[0009]

[0010] The modified antioxidant comprises an antioxidant and a neutralizer, wherein the antioxidant has a tert-butyl group, a benzene ring group and an aniline group, the neutralizer is an acidic substance, and the weight ratio of the antioxidant to the neutralizer is 100:(15-30).

[0011] Preferably, the antioxidant is 4,4'-dioctyldiphenylamine.

[0012] Preferably, the neutralizing agent is at least one of phosphoric acid, pyrophosphoric acid and metaphosphoric acid, more preferably phosphoric acid.

[0013] Preferably, the curing agent is a multifunctional isocyanate compound.

[0014] Furthermore, the curing agent is at least one of toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), and 4,4'-dicyclohexylmethane diisocyanate (HMDI), and more preferably HDI.

[0015] Preferably, the solvent is at least one of ethyl acetate, toluene, ethyl formate and butanone.

[0016] The technical solution adopted by the present invention to solve the above second technical problem is: a method for preparing the above protective film for protecting the surface of glass, characterized in that it comprises the following steps:

[0017] (1) preparing the modified antioxidant: adding the antioxidant to the neutralizer in a certain proportion, stirring to form a mixed solution, washing the mixed solution with water, filtering, and drying the filtered solid matter to prepare the modified antioxidant;

[0018] (2) dissolving the modified antioxidant in a solvent to form a modified antioxidant solution, stirring the polyurethane adhesive and the modified antioxidant solution, adding a corresponding weight portion of a curing agent, stirring evenly to form a coating, applying the coating to the surface of the substrate layer, and drying the coating to remove the solvent to form an adhesive layer on the substrate layer;

[0019] (3) The release layer is attached to the adhesive layer and after curing, the protective film for protecting the glass surface is obtained.

[0020] The technical solution adopted by the present invention to solve the third technical problem is: an application of the above-mentioned protective film for protecting the glass surface, characterized in that the protective film is used to be pasted on the glass surface.

[0021] Compared with the prior art, the advantages of the present invention are: First, the commonly used antioxidants are modified in a simple and easy manner; the modified antioxidants not only still contain two tert-butyl groups (-C(CH3)3) and a benzene ring structure (-C5H6) that can absorb free radicals to achieve an antioxidant effect; the aniline structure reacts with phosphoric acid to generate an ammonium phosphate structure.

[0022] Second: During processing, high temperature treatment will cause the polyurethane adhesive to thermally decompose and produce small molecules such as ammonia (NH3), resulting in bubbles and bubbling, which will greatly reduce the bonding effect between the adhesive and the glass interface and pollute the glass surface. The ammonium phosphate structure in the modified antioxidant absorbs heat and decomposes at high temperatures, and the regenerated phosphate ions can react and combine with such alkaline small molecules to reduce the adverse effects of the gas generated by thermal decomposition, thereby effectively preventing a significant decrease in bonding performance and ensuring that the glass surface remains clean. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with specific embodiments.

[0024] The protective film for protecting the glass surface of the present invention comprises a substrate layer, an adhesive layer and a release layer arranged in sequence. Except for the adhesive layer, other film layers can adopt existing technologies. In addition, a protective film layer can be arranged on the other side of the substrate layer or not.

[0025] Preferably, the substrate layer is an existing high temperature resistant polyester film material with a thickness of 20-125 μm. Of course, it can also be other existing substrate layers; the protective film layer is selected from one of acrylic, PU or other types of protective films; the release layer thickness is 25 to 150 μm.

[0026] The protective film is used to stick on the glass surface. Before sticking, tear off the release layer and then stick the adhesive layer on the glass surface. It is mainly used in etching or inkjet printing processes that have certain requirements on the surface tension of the glass.

[0027] The adhesive layer of the present invention comprises the following components in parts by weight:

[0028]

[0029] The modified antioxidant comprises an antioxidant and a neutralizer, wherein the antioxidant has a tert-butyl group, a benzene ring group and an aniline group, the neutralizer is an acidic substance, and the weight ratio of the antioxidant to the neutralizer is 100:(15-30).

[0030] The method for preparing a protective film for protecting a glass surface comprises the following steps:

[0031] (1) preparing a modified antioxidant: adding an antioxidant to a neutralizer in a certain proportion, stirring the mixture to form a mixed solution (stirring rate of 200 r / min, stirring time of 30 min), washing the mixed solution with water, filtering, and drying the filtered solid matter to prepare the modified antioxidant;

[0032] (2) dissolving the modified antioxidant in a solvent to form a modified antioxidant solution, adding the polyurethane adhesive and the modified antioxidant solution into a container and stirring them evenly, adding a corresponding weight portion of a curing agent, stirring evenly to form a coating (stirring rate of 300 r / min, stirring time of 10 min), applying the coating on the surface of the substrate layer, and forming an adhesive layer on the substrate layer after the coating is dried (drying oven temperature of 120° C., drying time of 3 min), and the thickness of the adhesive layer is 15±1 μm;

[0033] (3) The release layer is attached to the adhesive layer and after curing (the drying oven temperature is 50° C. and the curing time is 72 hours), the protective film for protecting the glass surface is obtained.

[0034] The present invention is described below in conjunction with specific embodiments:

[0035] Example 1

[0036] The method for preparing the protective film for protecting the glass surface of this embodiment comprises the following steps:

[0037] (1) Preparing a modified antioxidant: adding 100 parts of an antioxidant to 15 parts of a neutralizing agent, phosphoric acid, and stirring for 2 to 3 hours to form a uniform mixed solution, washing the mixed solution with water for multiple times, filtering, and drying the filtered solid matter to prepare the modified antioxidant;

[0038] (2) dissolving 5 parts of modified antioxidant in 5 parts of solvent ethyl acetate, stirring evenly to form a modified antioxidant solution, adding 100 parts of polyurethane adhesive UR-6800 and the modified antioxidant solution into a container and stirring evenly, adding 10 parts of curing agent HDI, stirring evenly for 10 minutes to form a coating, applying the coating on the surface of the substrate layer, drying at 120° C. for 3 minutes to remove the solvent, and forming an adhesive layer on the substrate layer after the coating is dried;

[0039] (3) The release layer is attached to the adhesive layer (if a protective film layer is provided, the protective film layer is attached to the substrate layer), and after curing in a drying oven at 50° C. for 72 hours, the protective film for protecting the glass surface is obtained.

[0040] Example 2

[0041] The method for preparing the protective film for protecting the glass surface of this embodiment comprises the following steps:

[0042] (1) Preparing a modified antioxidant: adding 100 parts of an antioxidant to 20 parts of a neutralizing agent, phosphoric acid, and stirring for 2 to 3 hours to form a uniform mixed solution, washing the mixed solution with water for multiple times, filtering, and drying the filtered solid matter to prepare the modified antioxidant;

[0043] (2) dissolving 10 parts of a modified antioxidant in 10 parts of a solvent, ethyl acetate, and stirring to form a modified antioxidant solution; adding 100 parts of a polyurethane adhesive, UR-6800, and the modified antioxidant solution to a container and stirring to form a coating; adding 12 parts of a curing agent, HDI, and stirring for 10 minutes to form a coating; applying the coating to the surface of the substrate layer; drying at 120° C. for 3 minutes to remove the solvent; and forming an adhesive layer on the substrate layer after the coating is dried;

[0044] (3) The release layer is attached to the adhesive layer and cured in a drying oven at 50° C. for 72 hours to obtain the protective film for protecting the glass surface.

[0045] Example 3

[0046] The method for preparing the protective film for protecting the glass surface of this embodiment comprises the following steps:

[0047] (1) Preparing a modified antioxidant: adding 100 parts of an antioxidant to 25 parts of a neutralizing agent, phosphoric acid, and stirring for 2 to 3 hours to form a uniform mixed solution, washing the mixed solution with water for multiple times, filtering, and drying the filtered solid matter to prepare the modified antioxidant;

[0048] (2) dissolving 10 parts of a modified antioxidant in 10 parts of a solvent, ethyl acetate, and stirring to form a modified antioxidant solution; adding 100 parts of a polyurethane adhesive, UR-6800, and the modified antioxidant solution to a container and stirring to form a coating; adding 15 parts of a curing agent, HDI, and stirring for 10 minutes to form a coating; applying the coating to the surface of the substrate layer; drying at 120° C. for 3 minutes to remove the solvent; and forming an adhesive layer on the substrate layer after the coating is dried;

[0049] (3) The release layer is attached to the adhesive layer and cured in a drying oven at 50° C. for 72 hours to obtain the protective film for protecting the glass surface.

[0050] Example 4

[0051] The method for preparing the protective film for protecting the glass surface of this embodiment comprises the following steps:

[0052] (1) Preparing a modified antioxidant: adding 100 parts of an antioxidant to 30 parts of a neutralizing agent, phosphoric acid, and stirring for 2 to 3 hours to form a uniform mixed solution, washing the mixed solution with water for multiple times, filtering, and drying the filtered solid matter to prepare the modified antioxidant;

[0053] (2) dissolving 15 parts of a modified antioxidant in 15 parts of a solvent, ethyl acetate, and stirring to form a modified antioxidant solution; adding 100 parts of a polyurethane adhesive, UR-6800, and the modified antioxidant solution to a container and stirring to form a coating; adding 15 parts of a curing agent, HDI, and stirring for 10 minutes to form a coating; applying the coating to the surface of the substrate layer; drying at 120° C. for 3 minutes to remove the solvent; and forming an adhesive layer on the substrate layer after the coating is dried;

[0054] (3) The release layer is attached to the adhesive layer and cured in a drying oven at 50° C. for 72 hours to obtain the protective film for protecting the glass surface.

[0055] Comparative Example 1

[0056] The method for preparing the protective film for protecting the glass surface of this comparative example comprises the following steps:

[0057] (1) dissolving 10 parts of an antioxidant in 15 parts of a solvent, ethyl acetate, and stirring to form an antioxidant solution; adding 100 parts of a polyurethane adhesive, UR-6800, and the aforementioned antioxidant solution into a container and stirring to form a coating; adding 12 parts of a curing agent, HDI, and stirring for 10 minutes to form a coating; applying the coating to the surface of the substrate layer; drying at 120° C. for 3 minutes to remove the solvent; and forming an adhesive layer on the substrate layer after the coating is dried;

[0058] (2) The release layer is attached to the adhesive layer and cured in a drying oven at 50° C. for 72 hours to obtain the protective film for protecting the glass surface.

[0059] Comparative Example 2

[0060] The method for preparing the protective film for protecting the glass surface of this comparative example comprises the following steps:

[0061] (1) Preparing a modified antioxidant: adding 100 parts of an antioxidant to 40 parts of a neutralizing agent, phosphoric acid, and stirring for 2 to 3 hours to form a uniform mixed solution, washing the mixed solution with water for multiple times, filtering, and drying the filtered solid matter to prepare the modified antioxidant;

[0062] (2) dissolving 10 parts of a modified antioxidant in 10 parts of a solvent, ethyl acetate, and stirring to form a modified antioxidant solution; adding 100 parts of a polyurethane adhesive, UR-6800, and the modified antioxidant solution to a container and stirring to form a coating; adding 12 parts of a curing agent, HDI, and stirring for 10 minutes to form a coating; applying the coating to the surface of the substrate layer; drying at 120° C. for 3 minutes to remove the solvent; and forming an adhesive layer on the substrate layer after the coating is dried;

[0063] (3) The release layer is attached to the adhesive layer and cured in a drying oven at 50° C. for 72 hours to obtain the protective film for protecting the glass surface.

[0064] Comparative Example 3

[0065] The method for preparing the protective film for protecting the glass surface of this comparative example comprises the following steps:

[0066] (1) 100 parts of polyurethane adhesive UR-6800 were added to a container, and 10 parts of curing agent HDI were added, and the mixture was stirred for 10 minutes to form a coating, and the coating was applied to the surface of the substrate layer, and dried at 120° C. for 3 minutes to remove the solvent. After the coating was dried, an adhesive layer was formed on the substrate layer;

[0067] (3) The release layer is attached to the adhesive layer and cured in a drying oven at 50° C. for 72 hours to obtain the protective film for protecting the glass surface.

[0068] Comparative Example 4

[0069] The method for preparing the protective film for protecting the glass surface of this comparative example comprises the following steps:

[0070] (1) Preparing a modified antioxidant: adding 100 parts of an antioxidant to 20 parts of a neutralizing agent, phosphoric acid, and stirring for 2 to 3 hours to form a uniform mixed solution, washing the mixed solution with water for multiple times, filtering, and drying the filtered solid matter to prepare the modified antioxidant;

[0071] (2) dissolving 20 parts of modified antioxidant in 20 parts of solvent ethyl acetate, stirring evenly to form a modified antioxidant solution, adding 100 parts of polyurethane adhesive UR-6800 and the modified antioxidant solution into a container and stirring evenly, adding 15 parts of curing agent HDI, stirring evenly for 10 minutes to form a coating, applying the coating on the surface of the substrate layer, drying at 120° C. for 3 minutes to remove the solvent, and forming an adhesive layer on the substrate layer after the coating is dried;

[0072] (3) The release layer is attached to the adhesive layer and cured in a drying oven at 50° C. for 72 hours to obtain the protective film for protecting the glass surface.

[0073] Comparative Example 5

[0074] The method for preparing the protective film for protecting the glass surface of this comparative example comprises the following steps:

[0075] (1) Preparing a modified antioxidant: adding 100 parts of an antioxidant to 20 parts of a neutralizing agent, phosphoric acid, and stirring for 2 to 3 hours to form a uniform mixed solution, washing the mixed solution with water for multiple times, filtering, and drying the filtered solid matter to prepare the modified antioxidant;

[0076] (2) dissolving 10 parts of a modified antioxidant in 10 parts of a solvent, ethyl acetate, and stirring to form a modified antioxidant solution; adding 100 parts of a polyurethane adhesive, UR-6800, and the modified antioxidant solution to a container and stirring to form a coating; adding 12 parts of a curing agent, TDI, and stirring for 10 minutes to form a coating; applying the coating to the surface of the substrate layer; drying at 120° C. for 3 minutes to remove the solvent; and forming an adhesive layer on the substrate layer after the coating is dried;

[0077] (3) The release layer is attached to the adhesive layer and cured in a drying oven at 50° C. for 72 hours to obtain the protective film for protecting the glass surface.

[0078] As shown in Appendix 1, the present invention includes 4 embodiments and 5 comparative examples. The type and amount of the substance added in each embodiment, as well as the peel strength, high temperature peel strength, holding force, and dyne value of the surface of the adhered object (glass) of the final tape are listed in the table.

[0079] The amount of each substance in the table without indicating the unit refers to the weight percentage; the peel strength test standard in Table 1 is GB / T2792-2014; the adhesion test standard is method G in GB / T 4851-2014, and the set temperature is 40°C; the dyne value of the surface of the object (glass) is tested by laminating the prepared protective film to the surface of the process glass. During this process, it should be noted that there are no bubbles, dust and other undesirable phenomena on the laminating surface to obtain sample 1; then the sample 1 is placed in an oven at 200°C for treatment for 30 minutes; after the high temperature ends, the sample 1 is cooled to room temperature, the protective film is removed, and the dyne value of the surface of the process glass is tested using a surface tension test pen (i.e., a dyne pen) to confirm the surface tension, and the surface tension of the process glass before and after the experiment is compared.

[0080]

[0081] The antioxidant used in the above-mentioned embodiments and comparative examples is 4,4'-dioctyldiphenylamine (ST#1), the solvent is ethyl acetate, and the polyurethane adhesive is UR-6800 produced by TOYOBO.

[0082] It can be found from the table that adding modified antioxidants can greatly improve the thermal stability of the tape, that is, the percentage of high-temperature peel strength decreases significantly, but excessive modified antioxidants will significantly reduce the peel strength; at the same time, adding modified antioxidants can ensure that the glass surface remains clean, that is, the dyne value of the glass surface can be guaranteed to be greater than 36, but excessive modified antioxidants will reduce the dyne value of the glass surface.

Claims

1. A protective film for protecting a glass surface, comprising a substrate layer, an adhesive layer and a release layer arranged in sequence, characterized in that: The adhesive layer includes the following components in parts by weight: 100 parts of polyurethane adhesive; 5-15 parts of modified antioxidant; 10-15 parts of curing agent; 5-10 parts of solvent; The modified antioxidant comprises an antioxidant and a neutralizer, wherein the antioxidant has a tert-butyl group, a benzene ring group and an aniline group, the neutralizer is an acidic substance, and the weight ratio of the antioxidant to the neutralizer is 100:(15-30).

2. The protective film for protecting a glass surface according to claim 1, characterized in that: The antioxidant is 4,4'-dioctyldiphenylamine.

3. The protective film for protecting a glass surface according to claim 1, characterized in that: The neutralizing agent is at least one of phosphoric acid, pyrophosphoric acid and metaphosphoric acid.

4. The protective film for protecting a glass surface according to claim 1, characterized in that: The curing agent is a multifunctional isocyanate compound.

5. The protective film for protecting a glass surface according to claim 4, characterized in that: The curing agent is at least one of toluene diisocyanate, hexamethylene diisocyanate and 4,4'-dicyclohexylmethane diisocyanate.

6. The protective film for protecting a glass surface according to claim 1, characterized in that: The solvent is at least one of ethyl acetate, toluene, ethyl formate and butanone.

7. A method for preparing a protective film for protecting a glass surface according to any one of claims 1 to 6, characterized in that: The steps include: (1) preparing the modified antioxidant: adding the antioxidant to the neutralizer in a certain proportion, stirring to form a mixed solution, washing the mixed solution with water, filtering, and drying the filtered solid matter to prepare the modified antioxidant; (2) dissolving the modified antioxidant in a solvent to form a modified antioxidant solution, adding the polyurethane adhesive and the modified antioxidant solution into a container and stirring them uniformly, adding a corresponding weight portion of a curing agent, stirring them uniformly to form a coating, applying the coating to the surface of the substrate layer, and forming an adhesive layer on the substrate layer after the coating dries; (3) The release layer is attached to the adhesive layer and after curing, the protective film for protecting the glass surface is obtained.

8. Use of the protective film for protecting a glass surface according to any one of claims 1 to 6, characterized in that: The protective film is used to be pasted on the glass surface.

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