WO2021197056A1 - Medium viscosity protective film emulsion and preparation method therefor - Google Patents

Abstract

A medium viscosity protective film emulsion and a preparation method therefor. The medium viscosity protective film emulsion comprises the following components: an acrylate monomer, a functional monomer, an emulsifier, an initiator, a neutralizing agent, and deionized water. Preferably, methyl methacrylate is a hard monomer, butyl acrylate and iso-octyl acrylate are soft monomers. Although the amount of the functional monomer is small, after a small amount of such monomer is added and is subjected to a polymerization reaction with the soft and hard monomers, the prepared acrylate emulsion polymer contains an amount of functional group with a high polarity, and thus can obviously increase the cohesive force and adhesive property of an adhesive. The pre-emulsified seed polymerization process is used, excellent water resistance is achieved, and at the same time excellent compliance is achieved, and the film suffers little change over time. Furthermore, the peeling force of a protective film prepared by the product does not increase by more than 10% after sticking to a board for half a year, and the protective film is easily peeled off when the protective film is removed, and does not pollute the surface of a substrate.

Description

Medium-viscosity protective film emulsion and preparation method thereof Technical field

The invention belongs to the technical field of protective film emulsions, and specifically relates to a medium-viscosity protective film emulsion and a preparation method thereof.

Background technique

Surface protective film is an extremely important product in the field of pressure-sensitive adhesives in recent years. It is made by coating a protective film emulsion on the surface of a PE or PVC film substrate. It is a film with a protective function for other materials. Material. The surface protective film is mainly applied on the surface of the material to protect the material from being scratched, polluted and corroded during processing, manufacturing, transportation and storage, and to retain the original high brightness and cleanliness of the surface of the protected product. The performance of the surface protective film requires no damage to the surface of the protective material when it is removed from the surface of the material to be protected, and no residual glue is left on the surface of the material. The key to the quality of the protective film is determined by the characteristics of the protective film emulsion. The current protective film market Most of the emulsions have the defect of large changes over time, which leads to the problem of very difficult to tear or even degumming of the protective film for a few months or even longer. In response to these problems, this patent proposes a medium-viscosity protective film emulsion with small changes over time. This product is an emulsion-to-material prepared with special functional monomers, imported high-quality emulsifiers, and advanced core-shell technology. Good compliance, little change over time, and no pollution to the surface of the material when removed from the protected surface.

Summary of the invention

1. The technical problem to be solved by the invention

The purpose of the present invention is to solve the problem that the existing protective film emulsion has poor conformability and it is difficult to tear the film after use.

2. Technical solution

In order to achieve the above objective, the technical solution provided by the present invention is as follows:

A medium-viscosity protective film emulsion of the present invention includes the following components: acrylate monomer, functional monomer, emulsifier, initiator, neutralizer and deionized water.

Preferably, the specific parts by weight of the components are: 40-50 parts of acrylate monomer, 1-4 parts of functional monomer, 0.5-2.5 parts of emulsifier, 0.2-0.6 parts of initiator, and 1~ 4 parts and 50-60 parts of deionized water.

Preferably, the acrylate monomer is any two or two of butyl acrylate, isooctyl acrylate, methyl methacrylate, ethyl acrylate, methyl acrylate, tert-butyl acrylate, and isobornyl acrylate A mixture of the above.

Preferably, the functional monomer is at least one of acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, β-carboxyethyl acrylate, and diallyl phthalate.

Preferably, the emulsifier is fatty alcohol ether sulfate, fatty alcohol alkyl sulfate, fatty alcohol polyoxyethylene ether sodium sulfate, alkyl diphenyl oxide disulfonate, isomeric C13 alcohol polyoxyethylene At least one of ether and fatty alcohol ethoxylate.

Preferably, the initiator is one of ammonium persulfate, potassium persulfate, and sodium persulfate, and the neutralizer is ammonia.

A preparation process of a medium-viscosity protective film emulsion, which is characterized in that it comprises the following steps:

S100. Prepare the emulsion, put 25-40% deionized water and 70-90% emulsifier into the emulsification tank, stir quickly for 20 minutes, add all the acrylate monomers and functional monomers, and stir quickly for 30 minutes to obtain Emulsion

S200, preparing an initiator aqueous solution, adding all the initiators into 4-10% deionized water to dissolve, to obtain an initiator aqueous solution;

S300. Prepare an emulsion, add the remaining deionized water and emulsifier into the reactor, heat up to 78-85°C, put in 3-8% of the emulsion prepared in step S100, and add 50-60% of the initiator prepared in step S200 Aqueous solution, react for 10-20 minutes, start adding the remaining emulsion and the initiator aqueous solution dropwise at a uniform rate at the same time, after the dripping is finished, keep the temperature at 85-90°C for 1 hour;

S400, adjust the pH, cool the emulsion prepared in step S300 to below 50°C, add neutralizer ammonia to adjust the pH to 7-9, stir evenly, filter out the material through a 200-mesh filter cloth, and obtain the required medium-viscosity protective film Lotion.

Preferably, the uniform dropwise addition of the remaining emulsion and the initiator aqueous solution requires the reaction temperature to be controlled at 80-90° C., and the dropping time is 3 to 4 hours.

A preparation process of a medium-viscosity protective film: using the above-mentioned medium-viscosity protective film emulsion, the protective film emulsion and the crosslinker aziridine are uniformly mixed, coated and dried, and the thickness of the coating is about 7 microns , That is, the medium-viscosity protective film.

Preferably, specifically, 0.1% of the crosslinker aziridine is added to the medium-viscosity protective film emulsion and mixed uniformly, and evenly coated on a 45-micron PE film with a wire rod, dried at 90°C, and the drying time is 3 minutes.

3. Beneficial effects

Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

A medium-viscosity protective film emulsion of the present invention includes the following components: acrylate monomer, functional monomer, emulsifier, initiator, neutralizer and deionized water, preferably methyl methacrylate is a hard monomer, Butyl acrylate and isooctyl acrylate are soft monomers. Although the amount of functional monomers is small, the addition of a small amount of this monomer will polymerize with the soft and hard monomers. The prepared acrylic emulsion polymer contains a certain degree of polarity. Higher functional groups can significantly increase the cohesion and bonding properties of the adhesive. Pre-emulsified seed polymerization process is adopted, which has excellent water resistance, and at the same time has excellent compliance, and the board has little change over time. In addition, the peeling force of the protective film prepared by the product does not increase by more than 10% after half a year, and the protective film is easily peeled off when the protective film is removed, and does not pollute the surface of the substrate.

Detailed ways

In order to facilitate the understanding of the present invention, the following will describe the present invention more comprehensively in conjunction with the embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided. The purpose is to make the disclosure of the present invention more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the technical field of the present invention; the terms used in the specification of the present invention herein are only for describing specific embodiments. The purpose is not to limit the present invention; the term "and/or" as used herein includes any and all combinations of one or more related listed items.

Example 1

The preparation process of the protective film emulsion of this embodiment is as follows:

Weigh 16.5g deionized water, 0.4g fatty alcohol ether sulfate, 0.2g isomeric C13 alcohol polyoxyethylene ether, put it in the emulsification tank, stir for 20 minutes, add 2.7g methyl methacrylate and 37.8g butyl acrylate Ester, 2.7g isooctyl acrylate, 1.35g acrylic acid, 0.45g diallyl phthalate, and stirred for 30 minutes to prepare an emulsion for use. Weigh 4 g of deionized water to dissolve 0.28 g of ammonium persulfate to prepare an aqueous initiator solution for use. Weigh 30g deionized water, 0.05g fatty alcohol ether sulfate, and 0.05g isomeric C13 alcohol polyoxyethylene ether into the reactor, stir and raise the temperature to 80-85℃, add 5% of the total amount of the emulsion, and the initiator 57% of the total amount of the aqueous solution was reacted for 15 minutes, and the remaining emulsion and the initiator aqueous solution were dropped synchronously and uniformly. The reaction temperature was controlled at 82-85°C, and the dropping time was 3 hours. After the dripping, the reaction was kept at 85°C for 1 hour. The temperature is lowered to below 50°C, the neutralizing agent ammonia water is added to adjust the pH to 7-9, and the mixture is evenly stirred, and the material is filtered out with a 200-mesh filter cloth to obtain a medium-viscosity protective film emulsion with little change over time.

Test: Add 0.1% crosslinker aziridine to the medium-viscosity protective film emulsion and mix it evenly. Use a wire rod to evenly coat the 45 micron PE film. Dry at 90°C for 3 minutes to control the adhesive layer. The thickness is about 7 microns, and the 180° peeling force is tested. The test method; according to GB/T 2792-2014, use a desktop tensile testing machine to test. After the test is dried, it is placed at room temperature for 20 minutes, 3 days, 30 days, and 90 days 180° Peel force change data.

Test Results:

180° peeling force	20 minutes	3 days	30 days	90 days	Increase
Sample 1	200g	205g	210g	220g	10%
Sample 2	210g	217g	220g	228g	8.6%

Conclusion: The PE protective film prepared by the medium-viscosity protective film emulsion prepared in this example is attached to the surface of the aluminum-plastic board substrate, and after being placed at room temperature for 3 to 6 months, when the protective film is removed, it is easy to peel off and there is no residual glue Contaminate the surface of the substrate.

Example 2

The preparation process of the protective film emulsion of this embodiment is as follows:

Weigh 90.0g deionized water, 3.0g fatty alcohol ether sulfate, 1.0g isomeric C13 alcohol polyoxyethylene ether, place in the emulsification tank, stir for 20 minutes, add 11.25g methyl methacrylate and 195.75g butyl acrylate Ester, 7.88g isooctyl acrylate, 5.67g hydroxypropyl acrylate, 4.6g β-carboxyethyl acrylate, stirred for 30 minutes to prepare an emulsion for use. Weigh 22.5 g of deionized water to dissolve 1.35 g of sodium persulfate to prepare an aqueous initiator solution for use. Weigh 150g of deionized water, 0.5g of fatty alcohol ether sulfate, and 0.5g of isomeric C13 alcohol polyoxyethylene ether in the reactor, stir and heat to 80-85℃, add 5% of the total emulsion, initiator 60% of the total amount of the aqueous solution was reacted for 20 minutes, and then the remaining emulsion and the initiator aqueous solution were dropped synchronously and uniformly. The reaction temperature was controlled at 82-85°C, and the dropping time was 3 hours. After the dripping, the reaction was kept at 85°C for 1 hour. The temperature is lowered to below 50°C, the neutralizing agent ammonia water is added to adjust the pH to 7-9, and the mixture is evenly stirred, and the material is filtered out with a 200-mesh filter cloth to obtain a medium-viscosity protective film emulsion with little change over time.

Test: Add 0.3% crosslinker aziridine to the medium-viscosity protective film emulsion and mix it evenly. Use a wire rod to evenly coat the 45-micron PE film. Dry at 90°C for 3 minutes to control the adhesive layer. The thickness is about 7 microns, and the 180° peeling force is tested. The test method; according to GB/T 2792-2014, use a desktop tensile testing machine to test. After the test is dried, it is placed at room temperature for 20 minutes, 3 days, 30 days, and 90 days 180° Peel force change data.

Test Results:

180° peeling force	20 minutes	3 days	30 days	90 days	Increase
Sample 1	150g	152g	155g	160g	6.7%
Sample 2	155g	158g	163g	170g	9.7%

Conclusion: The PE protective film prepared by the medium-viscosity protective film emulsion prepared in this example is attached to the surface of the aluminum-plastic board substrate, and after being placed at room temperature for 3 to 6 months, when the protective film is removed, it is easy to peel off and there is no residual glue Contaminate the surface of the substrate.

Example 3

The preparation process of the protective film emulsion of this embodiment is as follows:

Weigh 170.0g deionized water, 6.05g fatty alcohol ether sulfate, 1.45g isomeric C13 alcohol polyoxyethylene ether, put it in the emulsification tank, stir for 20 minutes, add 32.2g methyl methacrylate and 367.2g butyl acrylate Ester, 30.82g isooctyl acrylate, 13.85g methacrylic acid, 5.93g hydroxyethyl acrylate, stirred for 30 minutes to prepare an emulsion for use. Weigh 43.8 g of deionized water to dissolve 3.0 g of potassium persulfate to prepare an aqueous initiator solution for use. Weigh 310g of deionized water, 1.0g of fatty alcohol ether sulfate, and 0.7g of isomeric C13 alcohol polyoxyethylene ether into the reactor, stir and heat to 80-85°C, add 5% of the total emulsion, initiator 60% of the total amount of the aqueous solution was reacted for 20 minutes, and then the remaining emulsion and the initiator aqueous solution were dropped synchronously and uniformly. The reaction temperature was controlled at 82-85°C, and the dropping time was 3 hours. After the dripping, the reaction was kept at 85°C for 1 hour. Cool down to below 50°C, add neutralizer ammonia water to adjust the pH to 7-9, stir evenly, and filter out the material with 200 mesh filter cloth to obtain a medium-viscosity protective film emulsion with little change over time.

Test: Add 0.5% crosslinker aziridine to the medium-viscosity protective film emulsion and mix it evenly. Use a wire rod to evenly coat the 45 micron PE film. Dry at 90°C for 3 minutes to control the adhesive layer. The thickness is about 7 microns, and the 180° peeling force is tested. The test method; according to GB/T 2792-2014, use a desktop tensile testing machine to test. After the test is dried, it is placed at room temperature for 20 minutes, 3 days, 30 days, and 90 days 180° Peel force change data.

Test Results:

180° peeling force	20 minutes	3 days	30 days	90 days	Increase
Sample 1	100g	101g	102g	105g	5%
Sample 2	108g	110g	113g	115g	6.5%

Conclusion: The PE protective film prepared by the medium-viscosity protective film emulsion prepared in this example is attached to the surface of the aluminum-plastic board substrate, and after being placed at room temperature for 3 to 6 months, when the protective film is removed, it is easy to peel off and there is no residual glue Contaminate the surface of the substrate.

To sum up: One of the main factors affecting the mechanical properties of emulsion pressure sensitive adhesives is the glass transition temperature Tg of the emulsion copolymer. Generally, the glass transition temperature of pressure sensitive adhesives should be kept in the range of -20℃～-60℃. Different pressure-sensitive adhesive formulation systems with different application requirements have different optimal Tg values. The glass transition temperature can be adjusted by selecting a soft monomer with a very low glass transition temperature and a hard monomer with a higher glass transition temperature according to a certain ratio, so that it can have a good initial viscosity and cohesion while maintaining a certain cohesion. Keep sticky. Hard monomers have a high glass transition temperature. After copolymerization with soft monomers, they can produce better cohesive strength and provide adhesive peeling force; soft monomers have low glass transition temperature and give adhesives bonding performance. Functional monomer: contains functional groups such as carboxyl, hydroxyl, double bond, etc., which can impart other properties to the adhesive, such as: water resistance, heat resistance, aging resistance, crosslinking, etc., methyl methacrylate is preferred in the dispensing design of the present invention They are hard monomers. Butyl acrylate and isooctyl acrylate are soft monomers. Although the amount of functional monomers is small, the addition of a small amount of this monomer will polymerize with the soft and hard monomers to prepare the acrylic ester emulsion polymerization. Containing certain functional groups with higher polarity can significantly increase the cohesion and bonding properties of the adhesive. According to different applications, when the ratio between the soft monomer and the hard monomer in the formula is moderate, the pressure-sensitive adhesive with good performance can be prepared to meet the application requirements. The ratio of each monomer in the formula of the present invention is adjusted according to the glass transition temperature, which is a preferred ratio.

The above-mentioned embodiments only express a certain embodiment of the present invention. The description is more specific and detailed, but it should not be construed as a limitation on the scope of the present invention; it should be pointed out that for those of ordinary skill in the art, In other words, without departing from the concept of the present invention, a number of modifications and improvements can be made, which belong to the scope of protection of the present invention; therefore, the scope of protection of the patent of the present invention shall be subject to the appended claims.

Claims (10)

1. A medium-viscosity protective film emulsion is characterized by comprising the following components: acrylate monomer, functional monomer, emulsifier, initiator, neutralizer and deionized water.
2. The medium-viscosity protective film emulsion according to claim 1, wherein the specific parts by weight of the components are: 40-50 parts of acrylate monomer, 1-4 parts of functional monomer, and 0.5 parts of emulsifier. ~2.5 parts, 0.2~0.6 parts of initiator, 1~4 parts of neutralizer and 50~60 parts of deionized water.
3. The medium-viscosity protective film emulsion according to claim 2, wherein the acrylate monomer is butyl acrylate, isooctyl acrylate, methyl methacrylate, ethyl acrylate, methyl acrylate, acrylic acid A mixture of any two or more of tert-butyl ester and isobornyl acrylate.
4. A medium-viscosity protective film emulsion according to claim 2, wherein the functional monomer is acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, β-carboxyethyl acrylate, ortho At least one of diallyl phthalate.
5. A medium-viscosity protective film emulsion according to claim 2, wherein the emulsifier is fatty alcohol ether sulfate, fatty alcohol alkyl sulfate, fatty alcohol polyoxyethylene ether sodium sulfate, alkyl two At least one of phenyl oxide disulfonate, isomeric C13 alcohol polyoxyethylene ether, and fatty alcohol ethoxide.
6. The medium-viscosity protective film emulsion according to claim 2, wherein the initiator is one of ammonium persulfate, potassium persulfate, and sodium persulfate, and the neutralizer is ammonia.
7. The preparation process of a medium-viscosity protective film emulsion according to any one of claims 2 to 6, characterized in that it comprises the following steps:

   S100. Prepare the emulsion, put 25-40% deionized water and 70-90% emulsifier into the emulsification tank, stir quickly for 20 minutes, add all the acrylate monomers and functional monomers, and stir quickly for 30 minutes to obtain Emulsion

   S200, preparing an initiator aqueous solution, adding all the initiators into 4-10% deionized water to dissolve, to obtain an initiator aqueous solution;

   S300. Prepare an emulsion, add the remaining deionized water and emulsifier into the reactor, heat up to 78-85°C, put in 3-8% of the emulsion prepared in step S100, and add 50-60% of the initiator prepared in step S200 Aqueous solution, react for 10-20 minutes, start by dropping the remaining emulsion and the initiator aqueous solution at a uniform rate at the same time, after the dropping, keep the temperature at 85-90°C for 1 hour;

   S400, adjust the pH, cool the emulsion prepared in step S300 to below 50°C, add neutralizing agent ammonia to adjust the pH to 7-9, stir evenly, filter out the material through a 200-mesh filter cloth, and obtain the required medium-viscosity protective film Lotion.
8. The medium-viscosity protective film emulsion according to claim 7, characterized in that: the uniform dropwise addition of the remaining emulsion and the initiator aqueous solution requires the reaction temperature to be controlled at 80-90°C, and the dropping time is 3 to 4 hours.
9. A preparation process of a medium-viscosity protective film, which is characterized in that: the medium-viscosity protective film emulsion according to claim 7 is used, the protective film emulsion and the crosslinker aziridine are uniformly mixed, coated and dried, The thickness of the coating is about 7 microns, which is the medium-viscosity protective film.
10. The preparation process of a medium-viscosity protective film according to claim 9, characterized in that: specifically, the medium-viscosity protective film emulsion is mixed with 0.1% of the crosslinker aziridine and uniformly coated with a wire rod. On a 45 micron PE film, dry at 90°C for 3 minutes.