A release coating for hot melt pressure sensitive adhesives and a method for making the same

Abstract

The present application relates to the technical field of release coating, in particular to a release coating for hot melt pressure sensitive adhesive and a preparation method thereof. The present application provides a release coating for hot melt pressure sensitive adhesive, according to mass fraction, the preparation raw materials of the release coating include: release agent 100 parts, water 50-1000 parts, defoaming agent 0.2-0.8 parts, lubricant 0.2-1.5 parts, anti skinning agent 0-1 part, bridging agent 0-2 parts, wetting agent 0.1-1 part; the release agent includes polyvinyl alcohol or water-based emulsion. The release coating can avoid the problem of film warping.

Description

Technical Field

[0001] This invention relates to the field of isolation layer coating technology, and in particular to an isolation coating for hot melt pressure-sensitive adhesive and its preparation method. Background Technology

[0002] Hot melt pressure-sensitive adhesive, a type of pressure-sensitive adhesive, is a new type of adhesive tape made by mixing synthetic rubber, resin, and rubber oil, heating them to a molten state, and then coating them onto substrates such as cotton, cloth, or plastic film. Its biggest advantage is its low cost, but its adhesion is significantly affected by temperature. It is mainly used for various types of box sealing, paper packaging, beverage bottle labels, sealing aluminum foil, waterproof rolls, express delivery waybills, flexible packaging, and other packaging materials, as well as environmentally friendly paper pallets, and is suitable for various materials. However, existing hot melt pressure-sensitive adhesives can cause swelling of the film, leading to label peeling after application, which does not meet current requirements. Summary of the Invention

[0003] The purpose of this invention is to provide a release coating for hot melt pressure-sensitive adhesives and a method for preparing the same, wherein the release coating can prevent the film from peeling off.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a release coating for hot melt pressure-sensitive adhesives. The raw materials for preparing the release coating, by weight, include: 100 parts release agent, 500-1000 parts water, 0.2-0.8 parts defoamer, 0.2-1.5 parts lubricant, 0-1 parts anti-skinning agent, 0-2 parts crosslinking agent, and 0.1-1 parts wetting agent.

[0006] The separating agent includes polyvinyl alcohol or an aqueous emulsion.

[0007] Preferably, the aqueous emulsion includes one or more of acrylic emulsions, polyurethane emulsions, epoxy emulsions, and polyester emulsions.

[0008] Preferably, when the separating agent is an aqueous emulsion, the amount of the anti-skinning agent is 0, and the amount of water is 50-70 parts.

[0009] Preferably, the defoamer includes one or more of modified organosilicon, mineral oil, and alkynol;

[0010] The lubricant includes stearates and / or wax emulsions;

[0011] The anti-skinning agent includes one or more of methyl ethyl ketone oxime, o-methoxyphenol, o-isopropylphenol, methyl ethyl ketone ester, butyraldehyde ester, cyclohexanone palladium, and acetone oxime;

[0012] The crosslinking agent includes polyethyleneimine and / or a silane coupling agent;

[0013] The wetting agent includes one or more of alkynyl alcohol wetting agents, organosilicon wetting agents, and sodium sulfonate wetting agents.

[0014] The present invention also provides a method for preparing the coating described in the above technical solution. When the release agent includes polyvinyl alcohol, the method for preparing the release coating includes:

[0015] After mixing water and release agent, the mixture is first heated and then cooled. Then, under stirring, it is mixed with defoamer, lubricant, wetting agent, anti-skinning agent and crosslinking agent to obtain the first coating.

[0016] The first coating is applied to the surface of the original film to obtain the isolation coating.

[0017] The present invention also provides a method for preparing the coating described in the above technical solution. When the release agent includes polyvinyl alcohol, the method for preparing the release coating includes:

[0018] A portion of water and crosslinking agent are mixed and then coated onto the surface of the original film to form a pre-coated film.

[0019] The remaining water, polyvinyl alcohol, defoamer, lubricant, wetting agent, and anti-skinning agent are mixed in the fourth step to obtain the second coating.

[0020] The second coating is applied to the surface of the pre-coated film to obtain the isolation coating.

[0021] The present invention also provides a method for preparing the coating described in the above technical solution. When the separating agent includes an aqueous emulsion, the method for preparing the separating coating includes:

[0022] The fifth mixture of water, release agent, defoamer, lubricant, wetting agent, crosslinking agent and anti-skinning agent is mixed to obtain the third coating;

[0023] The third coating is applied to the surface of the original film to obtain the isolation coating.

[0024] Preferably, the first mixing is carried out under the condition of first stirring, and the speed of the first stirring is 50-100 r / min;

[0025] The temperature after heating is 90℃, and the holding time is 1 hour;

[0026] The second mixing is carried out under the condition of a second stirring, the stirring speed of which is 200 r / min;

[0027] The second mixing involves sequentially adding an antifoaming agent, a lubricant, a wetting agent, an anti-skinning agent, and a crosslinking agent to the mixture obtained after the first mixing.

[0028] Preferably, the third mixing is carried out under the condition of a third stirring, and the speed of the third stirring is 50-100 r / min;

[0029] The basis weight of the coating is 0.1–0.2 g / m³. 2 ;

[0030] The fourth mixing process involves mixing water and the sixth separating agent, heating the mixture to 90°C, cooling it down, and then sequentially adding an antifoaming agent, a lubricant, a wetting agent, and an anti-skinning agent while stirring.

[0031] Preferably, the fifth mixing is: under stirring conditions, an antifoaming agent, a lubricant, a wetting agent and a bridging agent are added sequentially to the separating agent.

[0032] This invention provides a release coating for hot-melt pressure-sensitive adhesives. The release coating, by weight, comprises the following raw materials: 100 parts release agent, 50-1000 parts water, 0.2-0.8 parts defoamer, 0.2-1.5 parts lubricant, 0-1 part anti-skinning agent, 0-2 parts crosslinking agent, and 0.1-1 parts wetting agent. The release agent includes polyvinyl alcohol or an aqueous emulsion. The polyvinyl alcohol in the coating of this invention forms a very dense film after drying, and the coating is incompatible with the hot-melt pressure-sensitive adhesive, providing excellent barrier properties against small molecule compounds in the adhesive. Simultaneously, the crosslinking agent in the coating can chemically bond with the film surface and also with the polyvinyl alcohol, resulting in excellent adhesion between the coating and the film, thus solving the problem of poor adhesion after adhesive application. Therefore, the coating will not cause swelling or damage to the coating after it is applied. The coating also avoids contact between the hot melt pressure-sensitive adhesive and the film, thus solving the problem of swelling and damage to the film caused by the hot melt pressure-sensitive adhesive, and thus solving the problem of label peeling of the hot melt pressure-sensitive adhesive film material. Attached Figure Description

[0033] Figure 1 The image shows the warpage of the original film with or without the isolation coating described in Example 2 after 30 days at room temperature. Detailed Implementation

[0034] This invention provides a release coating for hot melt pressure-sensitive adhesive, characterized in that, by weight, the raw materials for preparing the release coating include: 100 parts release agent, 50-1000 parts water, 0.2-0.8 parts defoamer, 0.2-1.5 parts lubricant, 0-1 parts anti-skinning agent, 0-2 parts crosslinking agent, and 0.1-1 parts wetting agent;

[0035] The separating agent includes polyvinyl alcohol or an aqueous emulsion.

[0036] In this invention, unless otherwise specified, all raw materials are commercially available products well known to those skilled in the art.

[0037] The raw materials for preparing the isolation coating of the present invention, by weight, include 100 parts of isolation agent; the isolation agent includes polyvinyl alcohol or an aqueous emulsion. In the present invention, the aqueous emulsion preferably includes one or more of acrylic emulsion, polyurethane emulsion, epoxy emulsion, and polyester emulsion; when the aqueous emulsion is two or more of the above-mentioned specific selections, the present invention does not impose any special limitation on the proportion of the above-mentioned specific substances, and they can be mixed in any proportion. In the present invention, the isolation agent can form a dense protective coating after drying and film formation, blocking the contact between the chemical substances in the hot melt pressure-sensitive adhesive and the film, thus preventing the hot melt pressure-sensitive adhesive from swelling the film.

[0038] Based on the mass fraction of the release agent, the raw materials for preparing the release coating of the present invention include 50 to 1000 parts of water. When the release agent is an aqueous emulsion, the amount of water is preferably 50 to 70 parts. When the release agent is polyvinyl alcohol, the amount of water is preferably 500 to 1000 parts.

[0039] Based on the mass fraction of the release agent, the raw materials for preparing the release coating of the present invention include 0.2 to 0.8 parts of defoamer, preferably 0.3 to 0.7 parts, and more preferably 0.4 to 0.6 parts. In the present invention, the defoamer preferably includes one or more of modified organosilicon, mineral oil, and alkynol; the modified organosilicon preferably includes one or more of BYK-021, BYK-024, and BYK1610; the mineral oil preferably includes one or more of NOPCO NXZ, SN-DEFOAMER180, and NOTETM 5000V; the alkynol preferably includes one or more of 104E, Dynol604, and Dynol810; when the defoamer is two or more of the above-mentioned specific selections, the present invention does not have any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. In the present invention, the function of the defoamer is to eliminate bubbles generated during the preparation of the release coating.

[0040] Based on the mass fraction of the release agent, the raw materials for preparing the release coating of the present invention include 0.2 to 1.5 parts of lubricant, preferably 0.4 to 1.2 parts, and more preferably 0.6 to 0.8 parts. In the present invention, the lubricant preferably includes stearate and / or wax emulsion; the stearate preferably includes one or more of zinc stearate, calcium stearate, and barium stearate; the stearate preferably exists as a zinc stearate emulsion; the present invention does not have any special limitation on the solid content of the zinc stearate emulsion, and a solid content known to those skilled in the art can be used. The wax emulsion preferably includes paraffin wax emulsion and / or polyethylene wax emulsion; the present invention does not have any special limitation on the solid content of the wax emulsion, and a solid content known to those skilled in the art can be used. When the lubricant is two or more of the above-mentioned specific selections, the present invention does not have any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. In the present invention, the function of the lubricant is to reduce friction during the coating process of the release coating.

[0041] Based on the mass fraction of the release agent, the raw materials for preparing the release coating of the present invention include 0-1 parts of an anti-skinning agent. When the release agent is an aqueous emulsion, the amount of the anti-skinning agent is preferably 0; when the release agent is polyvinyl alcohol, the amount of the anti-skinning agent is preferably 0.2-1 parts, more preferably 0.4-0.8 parts, and most preferably 0.5-0.6 parts. In the present invention, the anti-skinning agent preferably includes one or more of methyl ethyl ketone oxime, o-methoxyphenol, o-isopropylphenol, methyl ethyl ketone ester, butyraldehyde ester, cyclohexanone palladium, and acetone oxime; when the anti-skinning agent is two or more of the above-mentioned specific selections, the present invention does not have any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. In the present invention, the function of the skinning agent is to reduce the dry skin formed on the surface of the release coating liquid.

[0042] Based on the mass fraction of the release agent, the raw materials for preparing the release coating of the present invention include 0-2 parts of a crosslinking agent, preferably 0.8-1.8 parts, and more preferably 1.2-1.6 parts. In the present invention, the crosslinking agent preferably includes polyethyleneimine and / or a silane coupling agent, and the silane coupling agent is preferably one or more of KH550, Evonik DAMO, and 4721. When the crosslinking agent is two or more of the above-mentioned specific selections, the present invention does not have any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. In the present invention, the function of the crosslinking agent is to improve the adhesion between the release coating and the film.

[0043] Based on the mass fraction of the release agent, the raw materials for preparing the release coating of the present invention include 0.1 to 1 part of wetting agent, preferably 0.2 to 0.8 parts, and more preferably 0.4 to 0.6 parts. In this invention, the wetting agent preferably includes one or more of alkynol wetting agents, organosilicon wetting agents, and sodium sulfonate wetting agents; the alkynol wetting agent preferably includes one or more of Gas Chemical Surfynol 104E, Gas Chemical Surfynol 440, and Gas Chemical Surfynol 420; the organosilicon wetting agent preferably includes one or more of BYK3455, BYK3400, and TEGO Wet 270; the sodium sulfonate wetting agent preferably includes one or more of Solvay OT-75, Solvay GPG, and Solvay ABO; when the wetting agent is two or more of the above-mentioned specific selections, this invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio. In this invention, the function of the wetting agent is to reduce the surface tension of the isolation coating liquid.

[0044] The present invention also provides a method for preparing the isolation coating described in the above technical solution. When the isolation agent includes polyvinyl alcohol, the method for preparing the isolation coating includes:

[0045] After mixing water and release agent, the mixture is first heated and then cooled. Then, under stirring, it is mixed with defoamer, lubricant, wetting agent, anti-skinning agent and crosslinking agent to obtain the first coating.

[0046] The first coating is applied to the surface of the original film to obtain the isolation coating.

[0047] In this invention, the first mixing is preferably carried out under the condition of a first stirring, and the stirring speed is preferably 50-100 r / min, more preferably 60-90 r / min, and most preferably 70-80 r / min. The first mixing process preferably involves adding water to a container, starting stirring, and then adding a separating agent. In this invention, the temperature after heating is preferably 90°C, and the holding time is preferably 1 hour. This invention does not impose any special limitations on the cooling process; a process well-known to those skilled in the art can be used to cool to room temperature. In this invention, the second mixing is preferably carried out under the condition of a second stirring, and the stirring speed is preferably 200 r / min. In this invention, the second mixing preferably involves sequentially adding an antifoaming agent, a lubricant, a wetting agent, an anti-skinning agent, and a bridging agent to the mixture obtained after the first mixing. After adding the antifoaming agent, stirring is preferably performed for 20 minutes; after adding the lubricant, stirring is preferably performed for 5-10 minutes; after adding the wetting agent, stirring is preferably performed for 10-15 minutes; after adding the anti-skinning agent, stirring is preferably performed for 5-10 minutes; and after adding the bridging agent, stirring is preferably performed for 5-10 minutes.

[0048] After the second mixing is completed, the present invention preferably includes applying the obtained first coating to a storage tank of the coating head, and turning on low-speed stirring in the storage tank to prevent the coating from forming a skin.

[0049] After obtaining the first coating, the present invention applies the first coating to the surface of the original film to obtain the isolation coating.

[0050] In this invention, the coating process preferably includes:

[0051] The coating material in the storage tank is circulated and filtered through a pump to the coating head. The coating is then applied to the surface of the original film using methods such as curtain coating, anilox roller coating, wire rod coating, or doctor blade coating. After drying in an oven, the moisture content of the coating is controlled to be less than 1%, and the coating basis weight is 0.5–3 g / m². 2 Once rolled up, it becomes the finished product.

[0052] The present invention also provides a method for preparing the coating described in the above technical solution. When the release agent includes polyvinyl alcohol, the method for preparing the release coating includes:

[0053] A portion of water and crosslinking agent are mixed and then coated onto the surface of the original film to form a pre-coated film.

[0054] The remaining water, polyvinyl alcohol, defoamer, lubricant, wetting agent, and anti-skinning agent are mixed in the fourth step to obtain the second coating.

[0055] The second coating is applied to the surface of the pre-coated film to obtain the isolation coating.

[0056] A portion of water and a crosslinking agent are mixed and then coated onto the surface of the original film to form a pre-coated film.

[0057] In this invention, the third mixing is preferably carried out under the condition of a third stirring, and the stirring speed of the third stirring is preferably 50-100 r / min, more preferably 60-90 r / min, and most preferably 70-80 r / min. The process of the third mixing involves adding some water to the container, starting the stirring, and then adding the crosslinking agent. After the third mixing is completed, the stirring is further continued at a speed of 200 r / min for 10 minutes.

[0058] In this invention, the mass ratio of the partial water to the remaining water is preferably (1-1.2):1, more preferably (1.15-1.2):1, and most preferably 1.15:1.

[0059] This invention does not impose any special limitations on the coating process, and adopts a process well known to those skilled in the art to ensure that the moisture content of the prepared coating is less than 1% and the coating basis weight is 0.1-0.2 g / m³. 2 That's all.

[0060] After preparing the pre-coated film, the present invention mixes the remaining water, polyvinyl alcohol, defoamer, lubricant, wetting agent and anti-skinning agent to obtain the second coating.

[0061] In this invention, the fourth mixing is preferably performed by first heating the water and the release agent to 90°C and then cooling them down, followed by the sequential addition of an antifoaming agent, a lubricant, a wetting agent, and an anti-skinning agent while stirring. In this invention, the sixth mixing is preferably performed under sixth stirring conditions, with the stirring speed preferably being 50–100 r / min, more preferably 60–90 r / min, and most preferably 70–80 r / min. The sixth mixing process is preferably performed by adding water to the container, starting stirring, and then adding the release agent. In this invention, the holding time after heating is preferably 1 hour. This invention does not impose any special limitations on the cooling process; a process well-known to those skilled in the art can be used to cool to room temperature. In this invention, the stirring speed is preferably 200 r / min. In this invention, it is preferable to stir for 20 minutes after adding the defoamer; it is preferable to stir for 5 to 10 minutes after adding the lubricant; it is preferable to stir for 10 to 15 minutes after adding the wetting agent; it is preferable to stir for 5 to 10 minutes after adding the anti-skinning agent; and it is preferable to stir for 5 to 10 minutes after adding the crosslinking agent.

[0062] The present invention also preferably includes a storage tank for applying the obtained second coating to the coating head, wherein low-speed stirring is turned on in the storage tank to prevent the coating from forming a skin.

[0063] After obtaining the second coating, the present invention applies the second coating to the surface of the pre-coated film to obtain the isolation coating.

[0064] In this invention, the coating process preferably includes:

[0065] The coating material in the storage tank is circulated and filtered through a pump to the coating head. The second coating is applied to the pre-coated film surface using methods such as curtain coating, anilox roller coating, wire rod coating, or doctor blade coating. After drying in an oven, the moisture content of the coating is controlled to be less than 1%, and the coating basis weight is 0.5–3 g / m². 2 Once rolled up, it becomes the finished product.

[0066] The present invention also provides a method for preparing the coating described in the above technical solution. When the separating agent includes an aqueous emulsion, the method for preparing the separating coating includes:

[0067] The fifth mixture of water, release agent, defoamer, lubricant, wetting agent, crosslinking agent and anti-skinning agent is mixed to obtain the third coating;

[0068] The third coating is applied to the surface of the original film to obtain the isolation coating.

[0069] In this invention, the fifth mixing preferably includes adding a separating agent to the container, starting the stirring at 50-100 r / min, adding a defoamer, stirring for 20 min, adding a lubricant, stirring for 5-10 min, adding a wetting agent, stirring for 10-15 min, adding a crosslinking agent, and stirring for 5-10 min.

[0070] After the fifth mixing is completed, the present invention preferably includes applying the obtained third coating to a storage tank of the coating head, and turning on low-speed stirring in the storage tank to prevent the coating from forming a skin.

[0071] After obtaining the third coating, the present invention applies the third coating to the surface of the original film to obtain the isolation coating.

[0072] In this invention, the coating process preferably includes:

[0073] The coating material in the storage tank is circulated and filtered through a pump to the coating head. The coating is then applied to the surface of the original film using methods such as curtain coating, anilox roller coating, wire rod coating, or doctor blade coating. After drying in an oven, the moisture content of the coating is controlled to be less than 1%, and the coating basis weight is 0.5–3 g / m². 2 Once rolled up, it becomes the finished product.

[0074] The present invention does not impose any special limitations on the original film; any original film known to those skilled in the art for preparing hot melt pressure-sensitive adhesives can be used.

[0075] The following detailed description, in conjunction with embodiments, of the isolation coating for hot melt pressure-sensitive adhesive provided by the present invention and its preparation method, should not be construed as limiting the scope of protection of the present invention.

[0076] Example 1

[0077] By weight, the coating consists of: 100 parts of 0588 polyvinyl alcohol (50 mesh), 566 parts of water, 0.3 parts of BYK-024, 1.5 parts of zinc stearate emulsion (40% solid content), 0.5 parts of methyl ethyl ketone oxime, 2 parts of polyethyleneimine (molecular weight 10000), and 0.5 parts of Surfynol 104E from Gas Chemicals, USA.

[0078] Preparation method: Add water to the preparation container, start stirring at 50 r / min, add 0588 polyvinyl alcohol and start heating, raise the temperature to 90℃ within 1 hour, keep it at this temperature for 1 hour and then cool it to room temperature. Adjust the stirring speed to 200 r / min, add BYK-024 and stir for 20 min, add zinc stearate emulsion and stir for 7 min, add Surfynol 104E from Gas Chemicals (USA) and stir for 10 min, add methyl ethyl ketone oxime and stir for 5 min, add polyethyleneimine and stir for 8 min, stop stirring, use a pump to pump the coating into the storage tank of the coating head, start low-speed stirring in the storage tank to prevent the coating from forming a skin; apply the prepared coating to the surface of the original film;

[0079] The coating process on the original film surface: The coating material in the storage tank is circulated and filtered through a pump to the coating head. The coating material is then applied to the film surface using an anilox roller coating method. After drying in an oven, the moisture content of the coating is controlled to be less than 1%, and the coating basis weight is 1.6 g / m². 2 Once rolled up, it becomes the finished product.

[0080] Example 2

[0081] By weight, the coating consists of: 100 parts of 1799 polyvinyl alcohol (50 mesh), 566 parts of water, 0.3 parts of NOPCO NXZ, 2 parts of paraffin emulsion (30% solid content), 0.5 parts of methyl ethyl ketone oxime, 2 parts of polyethyleneimine (molecular weight 10000), and 0.2 parts of Solvay OT-75.

[0082] Preparation method: Add water to the preparation container, start stirring at 50 r / min, add 1799 polyvinyl alcohol and start heating, raise the temperature to 90℃ within 1 hour, keep it at this temperature for 1 hour and then cool it to room temperature. Adjust the stirring speed to 200 r / min, add NOPCO NXZ and stir for 20 min, add paraffin emulsion and stir for 5 min, add Solvay OT-75 and stir for 10 min, add methyl ethyl ketone oxime and stir for 5 min, add polyethyleneimine and stir for 8 min, stop stirring, use a pump to pump the coating into the storage tank of the coating head, start low-speed stirring in the storage tank to prevent the coating from forming a skin; apply the prepared coating to the surface of the original film;

[0083] The coating process on the original film surface: The coating material in the storage tank is circulated and filtered through a pump to the coating head. The coating material is then applied to the film surface using an anilox roller coating method. After drying in an oven, the moisture content of the coating is controlled to be less than 1%, and the coating basis weight is 2 g / m². 2 Once rolled up, it becomes the finished product.

[0084] Example 3

[0085] By weight, the coating consists of: 100 parts of 0588 polyvinyl alcohol (50 mesh), 666 parts of water, 0.3 parts of BYK1610, 1.5 parts of zinc stearate emulsion (40% solid content), 0.5 parts of methyl ethyl ketone oxime, 2 parts of polyethyleneimine (molecular weight 10000), and 0.5 parts of Surfynol 4400 from Gas Chemicals, USA.

[0086] Preparation method: Add 100 parts of water to a preparation container, start stirring at 200 rpm, add polyethyleneimine, stir for 10 minutes, stop stirring to prepare a pre-coating, pump the pre-coating onto the coating head, and coat the pre-coating onto the surface of the original film to prepare a pre-coated film (the coating basis weight of the pre-coated film is 0.2 g / m). 2 Add the remaining water to the preparation container, stir at 50 rpm, add 0588 polyvinyl alcohol and start heating, raise the temperature to 90°C within 1 hour, keep it at that temperature for 1 hour and then cool it to room temperature. Adjust the stirring speed to 200 rpm, add BYK1610 and stir for 20 minutes, add zinc stearate emulsion and stir for 7 minutes, add Surfynol 440 from Gas Chemicals (USA) and stir for 10 minutes, add methyl ethyl ketone oxime and stir for 5 minutes, stop stirring, use a pump to pump the coating into the storage tank of the coating head, start low-speed stirring in the storage tank to prevent the coating from forming a skin; apply the prepared coating onto the surface of the original film.

[0087] The coating process on the original film surface: The coating material in the storage tank is circulated and filtered through a pump to the coating head. The coating material is then applied to the film surface using an anilox roller coating method. After drying in an oven, the moisture content of the coating is controlled to be less than 1%, and the coating basis weight is 1.8 g / m². 2 Once rolled up, it becomes the finished product.

[0088] Test case

[0089] Coating adhesion test: 3M 810 standard tape was applied to the original film surface of the isolation coating and the uncoated isolation coating described in Example 3. The tape was pressed back and forth twice with a 2kg roller. After 20 minutes, the tape was quickly pulled off and the coating peeling was observed (as shown in Table 1).

[0090] The warpage height is the same as that of the thin film (the isolation coating described in Example 2). Figure 1 (Left of the image) and the original film without the isolation coating ( Figure 1 (See the right side of the image) After applying the hot melt pressure-sensitive adhesive, the material was placed in the test environment for the required time (as shown in Table 1). The sample was then cut into 10cm × 10cm squares, the release layer removed, and the adhesive side facing down. The height of the film's curl was measured; a positive value indicates upward curling, and a negative value indicates downward curling (as shown in Table 1). Figure 1 The image shows the actual product to demonstrate the degree of warpage after 30 days of testing at room temperature.

[0091] Table 1 shows the adhesion and warpage height of the original film with or without the isolation coating described in Example 2.

[0092]

[0093] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An application of a protective coating, characterized in that, The insulating coating is used to prevent the contact between chemicals in the hot melt pressure-sensitive adhesive and the film; The raw materials for preparing the isolation coating, by weight, are: 100 parts of isolation agent, 566 parts of water, 0.2-0.8 parts of defoamer, 0.2-1.5 parts of lubricant, 0-1 parts of anti-skinning agent, 2 parts of crosslinking agent, and 0.1-1 parts of wetting agent; The separating agent is polyvinyl alcohol; The bridging agent includes polyethyleneimine; The amount of the anti-skinning agent is not zero.

2. The application as described in claim 1, characterized in that, The defoamer includes one or more of modified organosilicon, mineral oil, and alkynol; The lubricant includes stearates and / or wax emulsions; The anti-skinning agent includes one or more of methyl ethyl ketone oxime, o-methoxyphenol, o-isopropylphenol, cyclohexanone oxime, and acetone oxime; The wetting agent includes one or more of alkynyl alcohol wetting agents, organosilicon wetting agents, and sodium sulfonate wetting agents.

3. The application as described in claim 1 or 2, characterized in that, The method for preparing the isolation coating includes: After mixing water and release agent, the mixture is first heated and then cooled. Then, under stirring, it is mixed with defoamer, lubricant, wetting agent, anti-skinning agent and crosslinking agent to obtain the first coating. The first coating is applied to the surface of the film to obtain the isolation coating.

4. The application as described in claim 1 or 2, characterized in that, The method for preparing the isolation coating includes: A portion of water and crosslinking agent are mixed and then coated onto the film surface to form a pre-coated film. The remaining water, polyvinyl alcohol, defoamer, lubricant, wetting agent, and anti-skinning agent are mixed in the fourth step to obtain the second coating. The second coating is applied to the surface of the pre-coated film to obtain the isolation coating.

5. The application as described in claim 3, characterized in that, The first mixing is carried out under the condition of first stirring, the stirring speed of which is 50~100 r / min; The temperature after heating is 90℃, and the holding time is 1 hour; The second mixing is carried out under the condition of a second stirring, the stirring speed of which is 200 r / min; The second mixing involves sequentially adding an antifoaming agent, a lubricant, a wetting agent, an anti-skinning agent, and a crosslinking agent to the mixture obtained after the first mixing.

6. The application as described in claim 4, characterized in that, The third mixing is carried out under the condition of a third stirring, wherein the stirring speed is 50~100 r / min; The basis weight of the coating is 0.1~0.2 g / m³. 2 ; The fourth mixing process involves mixing water and the sixth separating agent, heating the mixture to 90°C, cooling it down, and then sequentially adding an antifoaming agent, a lubricant, a wetting agent, and an anti-skinning agent while stirring.

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