JPH01288371A - Release agent, adhesive member and release sheet - Google Patents

Abstract

PURPOSE:To form a high strength silicone type cured film by preparing a release agent using polyfunctional alkoxysiloxane and an org. compound having a functional group capable of reacting therewith and solid at ambient temp. as main components. CONSTITUTION:Polyfunctional alkoxysiloxane and an org. compound having a functional group reacting therewith are used as main components and, if necessary, polyorganosiloxane having hydroxyl groups at both terminals thereof and/or a high-molecular compound having good adhesiveness to a polyvinyl chloride base material are additional compounded with said components to prepare a release agent. The silicone type cured film composed of the aforementioned release agent is formed to the single surface of a support base material and an adhesive layer is provided to the other surface of said base material to form an adhesive member. The silicone cured film composed of the aforementioned release agent is provided to the single surface or both surfaces of the support base material to form a release sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a release agent that forms a high-strength silicone-based cured film with excellent blocking resistance and non-staining properties, and that can be easily improved for polyvinyl chloride-based substrates. , and an adhesive member and release sheet having such a cured film.

Conventional techniques and problems When obtaining adhesive members such as surface protection sheets, release sheets, etc., a base treated with a release agent is used to make it easier to unwind the rolled product and peel it off from the adherend. wood is used. There are various types of base materials used depending on the purpose of use, but when heat resistance, weather resistance, and mechanical strength are required, polyvinyl chloride base materials are often used because of their excellent properties.

Conventionally, addition-type silicone release agents that can also be applied to polyvinyl chloride base materials have been used, but curing is inhibited by the stabilizer in the polyvinyl chloride and a film that can be used for practical purposes is not formed. A method using a certain condensed type has been proposed (Japanese Unexamined Patent Publication No. 1983-65565).

However, conventional condensation type silicone release agents have
The problem is that the cured film has poor blocking resistance (1'l), such as when it is in contact with the adherend for a long time, as it adheres tightly and becomes difficult to peel off, and that the cured film transfers and contaminates the adherend. Furthermore, when applied to a polyvinyl chloride base material, there was a problem that the cured film would rise from the base material due to the plasticizer in the polyvinyl chloride and easily fall off with light friction.

Means for Solving the Problems The present invention overcomes the above problems by forming a high-strength silicone-based cured film using a polyfunctional alkoxysiloxane.

That is, the present invention comprises a polyfunctional alkoxysiloxane, an organic compound which has a functional group capable of reacting with the polyfunctional alkoxysiloxane and is normally solid at JH, and optionally a polyorganosiloxane having hydroxyl groups at both ends. or/and a release agent characterized by additionally blending a polymeric compound with good adhesion to a polyvinyl chloride base material to form a high-strength silicone-based cured film, and one side of the supporting base material An adhesive member having a silicone-based cured film made of the above-mentioned release agent on one side and an adhesive layer on the other side, and a silicone-based cured film made of the above-mentioned ill agent on one or both sides of a supporting base material. The present invention provides a release sheet characterized by having the following properties.

A cured film made of polyfunctional alkoxysiloxane alone is hard, brittle, and has poor peeling performance, making it unsuitable for practical use as a film that imparts release properties. By doing so, flexibility is imparted while maintaining sufficient film strength, and peelability is also improved.

As a result, a cured film is formed that is tough, has excellent blocking resistance, non-adhesiveness (non-staining property), and has excellent release properties, and can be used practically as a release-imparting film.

On the other hand, by additionally blending a polyorganosiloxane having hydroxyl groups at both ends, the resulting cured film has better peeling performance and is given slipperiness.

Furthermore, by adding a polymeric compound with good adhesion to the polyvinyl chloride base material, it is possible to further improve the adhesion of the cured film to the polyvinyl chloride base material, allowing it to fall off from the base material. It can be made into a hardened film.

Examples of Constituent Elements of the Invention The polyfunctional alkoxysiloxane used in the present invention may have a plurality of alkoxy groups and can be condensed and cured by hydrolysis. Typical examples are methyl group,
Organoalkoxysiloxane containing an alkyl group such as an ethyl group or a propyl group or its halogen-substituted alkyl group, an alkoxy group such as a methoxy group or an ethoxy group, or a perfluorocarbon containing a long chain alkyl group with a trifluoromethyl group at the end. Examples include functional organoalkoxysiloxanes such as alkylalkoxysiloxanes. Alkoxysiloxane compounds used as surface treatment agents such as coupling agents and hard coating agents can be used as polyfunctional alkoxysiloxanes in the present invention. Incidentally, commercially available products include X-62-2296 (trade name: manufactured by Shin-Etsu Chemical Co., Ltd.).

Examples of organic compounds used in the present invention that have a functional group that reacts with polyfunctional alkoxysiloxane, such as a hydroxyl group or a carboxyl group, and are solid at room temperature include cellulose derivatives such as cellulose ether and cellulose ester; Examples include group-containing acrylic acid-based alkyl ester copolymers. Cellulose derivatives include methylcellulose, ethylcellulose,
Benzylcellulose, tritylcellulose, acetylcellulose, cellulose propionate, etc. are commonly used. Examples of hydroxyl group-containing acrylic acid-based alkyl ester copolymers include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, and triethylene glycol monoacrylate. Generally used are copolymers containing acrylic acid alkyl esters containing hydroxyl groups, such as acrylate and triethylene glycol monomethacrylate, and alkyl esters of acrylic acid or methacrylic acid having an alkyl group having 1 to 8 carbon atoms.

In the present invention, those that are soluble in the solvent used to prepare the stripping agent are preferably used.

The amount of the organic compound used is suitably 50 to 1000 parts by weight, preferably 100 to 800 parts by weight, per 100 parts by weight of the polyfunctional alkoxysiloxane. If the amount used is less than 50 parts by weight, the softening effect of the cured film will be poor, and if it exceeds 1000 parts by weight, the cured film will have poor peeling performance.

The cured film made of the above-mentioned polyfunctional alkoxysiloxane and an organic compound that has a functional group capable of reacting with the polyfunctional alkoxysiloxane and is solid at room temperature usually has a weight of 70 kg/cJ or more, especially 100 to 300 kg/cJ.
It has a film strength of kg/cd.

In the release agent of the present invention, a polyorganosiloxane having hydroxyl groups at both ends may be additionally blended, if necessary, to reduce the strength of the cured film formed. 5
Although it is common to lower it to about 0 kg/ant, it may be determined as appropriate depending on the purpose. The polyorganosiloxane used has a number average molecular weight of 5000 to 1.
50,000 is common, but is not limited to this. The combined use of such a polyorganosiloxane is more effective in improving the peeling performance of the cured film, imparting lighter unwinding properties, and imparting better slipperiness.

Cured films with good slip properties are preferably used for adhesive members such as surface protection sheets that are often subjected to processing such as cutting or bending. In particular, polydimethylsiloxane-based materials are preferably used from the viewpoint of imparting slipperiness. Polydimethylsiloxane having hydroxyl groups at both ends is X-62-2295 (trade name; manufactured by Shin-Etsu Chemical Co., Ltd.)
It is commercially available as.

The amount of the polyorganosiloxane used is suitably 50 to 500 parts by weight, preferably 80 to 300 parts by weight, per 100 parts by weight of the polyfunctional alkoxysiloxane. If the amount used is less than 50 parts by weight, the effect of improving peeling performance or slipperiness will be poor, and if it exceeds 500 parts by weight, the film strength will be significantly reduced (and blocking resistance and non-adhesive properties may be poor). .

In the release agent of the present invention, if necessary, a compound exhibiting good adhesion between the alkoxysiloxane film component and the supporting base material, such as a copolymer consisting of a constituent component of the alkoxysiloxane film and a constituent component of the supporting base material, may be used. The adhesion between the formed cured film and the supporting base material may be improved by additionally blending the like.

In particular, when the supporting base material is made of a polyvinyl chloride base material, such as a polyvinyl chloride film, a laminate thereof, or a polyvinyl chloride foam, the cured film will rise above the supporting base material due to the plasticizer in the polyvinyl chloride. If it easily falls off due to light friction, it is effective to add a polymeric compound that has good adhesion to the polyvinyl chloride base material to improve the adhesion.

As the polymer compound, one that is easily oriented toward the polyvinyl chloride base material when a release agent solution is applied is preferably used. As a result, the alkoxysiloxane film component is oriented on the surface side and the polymeric compound component is oriented on the support substrate side, and good adhesion to the substrate is achieved by the adhesive function of the polymeric compound component. Examples of polymeric compounds exhibiting such orientation include copolymers containing alkyl esters of acrylic acid or methacrylic acid having an alkyl group having 1 to 8 carbon atoms, and urethane/vinyl chloride copolymers. can give. As the copolymer containing an alkyl ester of acrylic acid or methacrylic acid as a component, a copolymer containing methyl methacrylate as a component is particularly preferably used.

On the other hand, urethane/vinyl chloride copolymers are based on ethyl carbamate (urethane bonding units) in the molecule.
-NHCOO-) and those containing vinyl chloride units are used. The content of vinyl chloride units is preferably 20 to 70% by weight. Such copolymers include V S -400
There are commercially available products such as 1. VS-4003 and VS-4021 (both trade names; manufactured by Toagosei Co., Ltd.). The urethane/vinyl chloride copolymer may contain as a copolymer component, for example, acrylic acid, methacrylic acid, or hydroxyethyl ester thereof, which has a functional group such as a carboxyl group or a hydroxyl group.

The amount of the above polymeric compound to be used is when a polyfunctional alkoxysiloxane, an organic compound that has a functional group that reacts with it and is solid at room temperature, and a polyorganosiloxane that has hydroxyl groups at both ends are used together. A suitable amount is 10 to 100 parts by weight, and preferably 20 to 80 parts by weight, per 100 parts by weight of the total. The amount used is 10
If the amount is less than 1 part by weight, the effect of improving the adhesion of the cured film to the polyvinyl chloride base material is poor, and if it exceeds 100 parts by weight, the peeling performance may be impaired.

The stripping agent of the present invention is typically prepared as a mixed solution of ingredients. An appropriate solvent may be used (and, if necessary, a curing catalyst made of an organic tin compound may be added. The amount added is 2 to 20% by weight based on the total silicone component.
is appropriate. Further, if necessary, a curing aid such as methylhydrosiloxane may be added in order to accelerate curing and facilitate control of the physical properties of the formed film. The amount added is suitably 1 to 10% by weight based on the total silicone components.

The releasability imparting treatment using the release agent of the present invention can be carried out in a conventional manner by applying the release agent to a supporting substrate and drying it to form a silicone-based cured film. The coating amount is 0.02 to 1 g/= based on solid content.
1 is suitable, and 0.1 to 0.7 g/ze is preferable. If the coating amount is less than 0.02g10f, defects may occur in the cured film that is formed, and sufficient removability may not be imparted.
It has poor adhesion to the supporting substrate and may transfer to an adherend such as an adhesive surface, causing contamination thereon. On the other hand, if the coating amount exceeds 1 g/d, it may tend to transfer to the adherend or fall off due to friction. The adhesion between the cured film of the release agent and the supporting substrate can be improved by adding an appropriate compound as a component of the releasing agent, as well as by using a surface that exhibits good adhesion between the cured film and the supporting substrate. The treatment may be carried out by a method in which the supporting base material is treated in advance with a treatment agent, or by a method in which this method and the above-mentioned blending method are used in combination.

The release agent of the present invention is preferably used in applications where it is desired to be adhered to an adhesive surface and to be easily peeled off from the adhesive surface, such as for back surface treatment of adhesive members and production of release sheets. It is also preferably used for producing adhesive members, etc. that are adhered and laminated to adherends, such as surface protection sheets.

The adhesive member of the present invention, typified by an adhesive tape or a surface protection sheet, has a silicone-based cured film made of the above-mentioned release agent on one side of a supporting base material, and an adhesive layer on the other side. The formation may be carried out by a known method, such as a method in which a cured film of a release agent is previously provided on one side of a support base and an adhesive is attached to the other side. Further, the release sheet of the present invention used as a separator etc. is one in which the silicone-based cured film described above is provided on one or both sides of a supporting base material. Appropriate materials may be used as the support base material for the adhesive member and the release sheet. Commonly used are paper, plastic laminated paper, cloth,
Plastic laminate cloth, plastic film, metal foil, foam, etc. are used. In particular, when the supporting base material is required to have heat resistance 11, weather resistance, and mechanical strength, a polyvinyl chloride base material is preferably used.

Effects of the Invention According to the release agent of the present invention, it is possible to form a silicone-based high-strength cured film made of alkoxysiloxane, and the cured film has good peeling performance and has good blocking resistance to adherends. , excellent non-staining property (non-shedding property).

It also has the advantage that modification treatment for improving peelability, slipperiness, or adhesion to a supporting substrate can be carried out by a simple operation of adding a necessary straw agent. In particular, by using a polyorganosiloxane having hydroxyl groups at both ends, it is possible to form a cured film with better peelability or slipperiness. Furthermore, by using a polymeric compound that has good adhesion to a polyvinyl chloride base material, it is possible to form a cured film that has better adhesion to the polyvinyl chloride base material.

Therefore, the adhesive member or release sheet having a silicone-based cured film made of such a release agent has excellent release performance and, if necessary, also has slippage 11 to prevent it from falling off from the supporting substrate. The body is less likely to be contaminated. Therefore, when the adherend has an adhesive surface, the adhesive strength is excellently maintained.

Examples Example 1 (where n is an integer of 1 to 20, m is an integer of 0 to 20)
10 parts of polyfunctional methoxysiloxane represented by the above formula (parts by weight, the same applies hereinafter), 10 parts of ethyl cellulose,
A 2% by weight solution of the stripping agent was obtained by dissolving 1 part of the organic tin compound in a mixed solvent of toluene and ethyl acetate.

Next, the release agent solution was applied to one side of a 25 part m thick polyester lime at a coating amount (solid content) of 0.2 g/nf and dried to obtain a release sheet. Further, on the other side of the release sheet, a rubber adhesive layer having a thickness of 10μ4 was provided to obtain a surface protection sheet.

Example 2 A release agent solution was obtained in accordance with Example 1, except that the amount of ethyl cellulose used was 30 parts, and a release sheet and a surface protection sheet were obtained using this solution.

Example 3 A release agent solution was obtained in accordance with Example 1, except that the amount of ethyl cellulose used was 40 parts, and a release sheet and a surface protection sheet were obtained using this solution.

Example 4 A release agent solution was obtained in accordance with Example 1, except that the amount of ethyl cellulose used was 50 parts, and a release sheet and a surface protection sheet were obtained using this solution.

Example 5 A release agent solution was obtained in accordance with Example 1, except that the amount of ethyl cellulose used was 60 parts, and a release sheet and a surface protection sheet were obtained using this solution.

Example 6 A release agent solution was obtained in accordance with Example 1, except that the amount of ethyl cellulose used was 80 parts, and a release sheet and a surface protection sheet were obtained using this solution.

Example 7 210 parts of the polyfunctional methoxysiloxane described above, 60 parts of ethylcellulose, 25 parts of polydimethylsiloxane having hydroxyl groups at both ends, 2 parts of methylhydrosiloxane, and 2 parts of an organotin compound were mixed with toluene. A 2% by weight solution of the stripping agent was obtained by dissolving it in an ethyl acetate mixed solvent,
Using this, a release sheet and a surface protection sheet were obtained according to Example 1.

Example 8 210 parts of the polyfunctional methoxysiloxa described above, 30 parts of ethyl cellulose, 20 parts of the acrylic acid copolymer,
5 parts of the stripping agent by dissolving 2 parts of the organic tin compound in toluene.
A weight percent solution was obtained. The acrylic acid copolymer is composed of 40 parts of butyl acrylate, 60 parts of methyl methacrylate, and 610 parts of 2-hydroxyethyl acrylate.

Next, the above release agent solution was applied to one side of a 70 μm thick polyvinyl chloride film in an amount (solid content) of 0.3 g/d.
A release sheet was obtained by coating and drying. Further, a rubber adhesive layer having a thickness of lhm was provided on the other side of the release sheet to obtain a surface protection sheet.

Example 9 A release agent solution was obtained according to Example 8, except that a urethane/vinyl chloride copolymer (vinyl chloride unit content: 50%) was used in place of the acrylic acid copolymer, and this solution was used. A release sheet and a surface protection sheet were obtained.

Example 10 10 parts of the polyfunctional methoxysiloxane described above, 60 parts of ethyl cellulose, 25 parts of polydimethylsiloxane having hydroxyl groups at both ends, 20 parts of acrylic acid copolymer, 2 parts of organotin compound, A 2% by weight solution of a release agent was obtained by dissolving 2 parts of methylhydrosiloxane in a mixed solvent of toluene, yuryl acetate, and chilli, and using this solution, a release sheet and a surface protection sheet were obtained according to Example 8. However, the application amount (solid content) of the release agent is 0.1 g/nf, 0
．． 2g/nf, 0.35g/+j or 0.7g/+
There are four ways of J. The acrylic acid copolymer is composed of 50 parts of butyl acrylate, 50 parts of methyl methacrylate, and 2 parts of 2-hydroxyethyl acrylate.

Example 11 10 parts of the polyfunctional methoxysiloxane described above, 40 parts of ethyl cellulose, 25 parts of polydimethylsiloxane having hydroxyl groups at both ends, 40 parts of an acrylic acid copolymer, 2 parts of an organotin compound, 1 part of methyl hydrosiloxane and 10 parts of dioctyl phthalate were dissolved in toluene to obtain a 3% by weight solution of a release agent, and this was used to obtain a release sheet and a surface protection sheet in accordance with Example 8. However, the application amount (solid content) of the release agent is 0.2g/11
! or 0.4 g/i. In addition, the said acrylic acid copolymer consists of 100 parts of methyl methacrylate and 5 parts of 2-hydroxyethyl acrylate.

Example 12 10 parts of the polyfunctional methoxysiloxane described above, 50 parts of ethyl cellulose, 20 parts of polydimethylsiloxane having hydroxyl groups at both ends, 15 parts of an acrylic acid copolymer, and 3 parts of an organotin compound, Dissolve 1 part of methylhydrosiloxane in toluene to make 5% by weight of the stripping agent.
A solution was obtained, and a release sheet and a surface protection sheet were obtained according to Example 8 using this solution. The acrylic acid copolymer is composed of 40 parts of butyl acrylate, 60 parts of methyl methacrylate, and 10 parts of 2-hydroxyethyl acrylate.

Example 13 A release agent was obtained in accordance with Example 12, except that a urethane/vinyl chloride copolymer (vinyl chloride unit content: 50% by weight) was used in place of the acrylic acid copolymer, and a release sheet was prepared using this. and a surface protection sheet.

Example 14 10 parts of the polyfunctional methoxysiloxane described above, 80 parts of ethyl cellulose, 35 parts of polydimethylsiloxane having hydroxyl groups at both ends, 60 parts of an acrylic acid copolymer, and 3 parts of an organotin compound, 2 parts of methylhydrosiloxane and 3% by weight of the stripping agent are dissolved in toluene.
A solution was obtained, and a release sheet and a surface protection sheet were obtained according to Example 8 using this solution. The acrylic acid copolymer is composed of 40 parts of butyl acrylate, 60 parts of methyl methacrylate, and 5 parts of 2-hydroxyethyl acrylate.

Comparative Example 1 A release sheet and a surface protection sheet were obtained according to Example 8 using a commercially available condensation type silicone release agent (KS-705 manufactured by Shin-Etsu Silicone Co., Ltd.).

Comparative Example 2 A release sheet and a surface protection sheet were obtained in accordance with Example 8 using a release agent prepared by mixing an acrylic resin with the commercially available condensation type silicone release agent described above in accordance with JP-A-55-65565.

The following tests were conducted on the release agents, release sheets, or surface protection sheets obtained in Evaluation Test Examples and Comparative Examples.

[Film strength] After applying a release agent onto a release sheet so that the thickness after drying is approximately 30 μm and drying it, the cured film is peeled off and cut into a tape shape with a width of 10 om+, and its tensile strength (
Measurement was carried out at 20° C., tensile speed of 300 m++/min, and chuck interval of 10 nwi).

[Peeling force] After pressing a rubber adhesive tape by moving a 2 kg rubber roller back and forth once on the treated surface of a release sheet, I wanted to measure the force required to peel off the adhesive tape at 180 degrees beer and a pulling speed of 300 mm/min. ).

[Rewindability] The surface protection sheet was used as a roll and its unwinding properties were investigated.

[Blocking resistance] (1) Presence or absence of accompaniment [] A stainless steel plate (SIJS304 thickness 0.4 mm)
Or attach a surface protection sheet to one side of the aluminum plate,
A BA stainless steel plate or aluminum plate is placed on top of the treated surface of the surface protection sheet and the weight is 2 kg/cni.
When the upper [ ] A stainless steel plate or aluminum plate is picked up after being left in an atmosphere of 60°C, 90% R, and I+ for 24 hours with a load applied, the lower BA stainless steel plate or aluminum plate We investigated whether or not they closely accompany each other.

(2) Adhesive strength The treated surface of the surface protection sheet and the above BA stainless steel plate together under a pressure of 2 kg/cnt, 60°C, 90%
After 24 hours of pressure bonding in an R711 atmosphere, the force required to peel off the release sheet was measured (180 degrees beer, pulling speed 300 wn/min).

[Non-staining] The DA stainless steel plates tested for blocking resistance were visually observed for the presence or absence of whitened areas due to transfer of the hardened film.

The above test results are shown in the table.

*: Defective means that the adhesive force was reduced due to contamination of the adhesive surface by the cured film. Moreover, *; (large) means that the area of the whitened part is large.

From the table, it can be seen that the cured film made of the release agent of the present invention has high film strength and is excellent in release characteristics, blocking resistance, non-staining property, and substrate adhesion.

E-slip property] The surface protection sheet using the polyvinyl chloride film as the base material in Example 8 and later was adhered to a B^ stainless steel plate via its adhesive surface, and this was pressed to a diameter of 1 with a 60t press.
00 mm, with a depth of 251,111 mm, and evaluated based on the degree of breakage of the supporting base material at that time.Example 1 containing a polydimethylsiloxane component
No breakage was observed in the supporting base materials for those with ratings of 0 to 14 based on their good sliding properties.

Patent applicant: Nitto Denko Corporation

Claims (1)

[Claims] 1. It is characterized by forming a high-strength silicone-based cured film, which is composed of a polyfunctional alkoxysiloxane and an organic compound that has a functional group that can react with the polyfunctional alkoxysiloxane and is solid at room temperature. paint remover. 2. The release agent according to claim 1, further comprising a polyorganosiloxane having hydroxyl groups at both ends. 3. The release agent according to claim 1 or 2, further comprising a polyvinyl chloride base material and a polymeric compound having good adhesive properties. 4. An adhesive member comprising a silicone cured film made of the release agent according to claim 1, 2 or 3 on one side of a supporting base material and an adhesive layer on the other side. 5. A release sheet comprising a silicone cured film comprising the release agent according to claim 1, 2 or 3 on one or both sides of a supporting base material.