JPH02129219A - Silicone releasing agent, self-adhesive member and separator - Google Patents

Abstract

PURPOSE:To obtain the title releasing agent having excellent curing characteristics and forming a releasable film printable with an oil-based ink by mixing a specified polyorganosiloxane, a fine particle of a silicone rubber elastomer and an onium salt curing catalyst. CONSTITUTION:The tilt releasing agent is prepared from a polyorganosiloxane of the formula [wherein R is a 1-20C alkyl, cycloalkyl, aryl or aralkyl; X is an epoxy group; Y is a polyether or polymethylene group; m/(l+m+n) is 0.05-90%; n/(l+n+m) is 0.5-90%], a fine particle of a silicone rubber elastomer having one or more functional groups such as phenyl, epoxy, hydroxyl or mercapto groups and a mean particle diameter of 0.1-20mum and an onium salt curing agent (e.g., an ultraviolet reactive sulfonium salt).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a silicone release agent containing fine particles of silicone rubber elastic material and forming a release film having excellent oil-based ink printability, and an adhesive member having such a film. and related to separators.

BACKGROUND OF THE INVENTION In adhesive members such as adhesive tapes, the back side of the supporting base material is treated with a release agent so that the adhesive side can be easily peeled off from the back side of the base material. Similarly, it is desirable that it be printable for purposes such as writing addresses.

Further, from the viewpoints of environmental hygiene, fire safety, energy saving, and efficiency of releasability imparting treatment, it is desirable to use a release agent that can be applied without solvent.

Conventional techniques and problems Conventionally, as a silicone release agent for forming a printable release film, a mixture of special polysiloxane with finely powdered silica or ethyl cellulose has been known. , No. 59-147048). However, there was a fatal problem in that the release agent did not cure sufficiently and the formed film had poor release properties. Furthermore, in order to ensure the viscosity and homogeneity of the release agent, it is necessary to apply the release agent as a dispersion using an organic solvent, which poses the problem that solvent-free application is difficult.

On the other hand, a solvent-free silicone release agent has been known in which an onium salt curing catalyst is blended with a polyorganosiloxane containing an epoxy functional component in the molecule, and is cured by ultraviolet irradiation ( JP-A-56-38350, JP-A-60-47064).

However, there was a problem in that the formed film could not be printed with oil-based ink. In addition, the formed film tends to be insufficiently cured, requiring a large amount of UV irradiation to cure it to a practical level, and even in that case, the peeling characteristics of the formed film tend to vary (and the adhesive surface to which it is attached) There was also the problem that the adhesive strength deteriorated due to contamination.

Means for Solving the Problems The present inventor has overcome the above problems and has developed a silicone-based release agent that can be applied without solvent, can be printed on the formed film with oil-based ink, and has good curing properties. As a result of intensive research for development, it was discovered that the purpose could be achieved by using polyorganosiloxane containing polyether/polymethylene components in the molecule and silicone rubber elastomer fine particles, and the present invention has been made. It's arrived.

That is, the present invention is based on the general formula (wherein R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group, X is an epoxy group-functional organic group, and Y is a boether polymethylene group, and m/(1!+m + n) is 0.
05-90%, and n/<e +m+n) is 0.5
~90%. ), silicone-based rubber elastomer fine particles, and an onium salt-based curing catalyst; an adhesive member having a releasable film on one side and an adhesive layer on the other side, and a releasable film comprising the silicone release agent described above on one or both sides of a supporting base material. It provides a separator.

Function: By using silicone rubber elastic fine particles, the wettability of the film formed with oil-based ink and, as a result, the printing properties are improved. On the other hand, the polyorganosiloxane represented by the above general formula has excellent compatibility with onium salt curing catalysts based on the polyether/polymethylene components contained in the molecule, and has good and stable UV curability or heat curability. Shows curability.

As a result, a silicone-based release film with excellent printability and release properties is formed.

Examples of Constituent Elements of the Invention The polyorganosiloxane used in the present invention is represented by the following general formula.

In the general formula, R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group. Methyl group is preferable from the viewpoint of peeling performance.

X is an epoxy functional organic group. For example,
Examples include γ-glycidyloxybrobyl group, β-(3,4-epoxycyclohexyl)ethyl group, β-(4-methyl-3,4-epoxycyclohexyl), and the like.

Y is a polyether polymethylene group. This group is
Any polyether/polymethylene group-containing compound that has good compatibility with the onium salt curing catalyst may be used. An example of this is the general formula: % Formula %. In the formula, R1 is a polymethylene group. R2 is an ethylene group: (-CH2CH2)
, a propylene group: (CH2CH(CH3) -) or a butylene group: (CH2CH(C2Hs)).

R3 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. In the present invention, it is preferable that the polymethylene group (R1) is a trimethylene group (CH2C82CH2) from the viewpoint of easy availability. Polymerization degree y of polyether part
Although it depends on the content ratio of polyether polymethicone groups in the polyorganosiloxane, in general, from the point of view of improving compatibility with the curing catalyst, 2 to 100 is appropriate, and 2 to 4.
0 is preferred.

e, m, and n in the general formula mean the number of each structural unit contained. In the present invention, m/(e+m+n) is 0.05
~90%, and n/(e+m+n) of 0.5 to 90% is suitable. The m/<e +m+n) is 0.
If it is less than 0.5%, the resulting release agent will have poor curability, and if it exceeds 90%, the formed release film will have poor release performance. If n/(e+m+n) is less than 0.5%, the compatibility with the onium salt curing catalyst, the curability of the resulting release agent, and the oil-based ink printability of the release film will be poor, and if n/(e+m+n) is less than 90%. The releasable film becomes poor in releasability.

When imparting solvent-free coating properties to the release agent, the number average molecular weight is 500 to soo, ooo, especially 1.000 to soo.
, ooo polyorganosiloxanes are preferably used.

The above-mentioned polyorganosiloxane containing an epoxy functional organic group and a polyether/polymethylene group in the molecule can be prepared, for example, by the following method.

That is, it has a predetermined number of unsubstituted hydrogens so as to have the content ratio of each structural unit described above, and the remaining hydrogens have 1 to 2 carbon atoms.
Polysiloxane substituted with 0 alkyl group, cycloalkyl group, aryl group, or aralkyl group and a functional group that has an ethylenic double bond such as olefin gnosidyl ether or that can react with hydrogen bonded to silicon Reacting a predetermined amount of an epoxy group-containing compound with a predetermined amount of a polyether compound having an ethylenic double bond, such as olefin or ethylene glycol, or a functional group capable of reacting with silicon-bonded hydrogen. It can be obtained by a method in which an epoxy group-containing compound and a polyether compound are introduced through unsubstituted hydrogen in the polysiloxane by hydrosilylation or the like.

In addition, in this invention, the series of each structural unit may be block-like and may be random.

The silicone-based rubber elastic fine particles used in the present invention may be those containing silicone rubber as a component (
There are no particular limitations on the type.

Those having at least one functional group such as a phenyl group, an epoxy group, a hydroxyl group, and a mercapto group are preferably used from the viewpoint of miscibility with polyorganosiloxane and strength of the resulting peelable film. The particles may have any shape, such as spherical or amorphous, and preferably have an average particle diameter of 0.1 to 20 μs from the viewpoint of miscibility and printability with oil-based ink.

The amount of silicone rubber elastomer fine particles blended is preferably 5 to 95% by weight, particularly 10 to 70% by weight, based on the total solid content of the release agent. If the blending ratio is less than 5% by weight, the releasable film formed will have poor oil-based ink printability;
If it exceeds % by weight, it becomes difficult to mix, and the formed release film has poor release properties, such as an increase in the adhesive force with the adhesive surface and a decrease in the adhesion force with the object to be treated, making it easy to fall off.

The release agent of the present invention can be cured by ultraviolet irradiation or heating using an onium salt curing catalyst. The onium salt curing catalyst to be used is not particularly limited (any known catalyst may be used. Examples thereof include the formula: % formula % (where Ar is an aryl group, R is an alkyl group or an aryl group, Z- BF4- PF6- ASF8-3
It is a non-basic and non-nucleophilic anion such as bF s -5bC1e -H3O4-ClO4-. ), diazonium salts, sulfonium salts, iodonium salts, etc.

The onium salt curing catalyst is blended in an amount of 0.1 to 20 parts by weight, especially 0.1 to 20 parts by weight, per 100 parts by weight of polyorganosiloxane.
5 to 10 parts by weight are suitable. If the amount is less than 0.1 parts by weight, the curability will be poor, and if it exceeds 20 parts by weight, the peeling performance may be impaired.

In the release agent of the present invention, a coupling agent such as a silane type, a filler, a pigment or a coloring agent, etc. may be added as necessary. Furthermore, if necessary, a monomer having one or more epoxy functional groups may be blended. Such monomers are effective in dispersing onium salt-based curing catalysts, and improve curability,
It is also effective in improving printing performance. Examples of commonly used monomers include ethylene glycol diglycidyl ether, glycerin diglycidyl ether, vinylcyclohexene dioxide, limonene dioxide, 3,
Examples include 4-epoxycyclohexylmethyl-3', 4'-epoxycyclohexylcarboxylate, and bis-(6-methyl-3,4-epoxycyclohexyl) adipate. The blending amount of the monomer having an epoxy functional group is 1 per 100 parts by weight of polyorganosiloxane.
-10,000 parts by weight is appropriate, and 10 to 10,000 parts by weight is preferred. In that case, the amount of onium salt curing catalyst used is suitably 0.1 to 20 parts by weight per 100 parts by weight of the monomer and polyorganosiloxane in total.

The silicone release agent of the present invention can be prepared by appropriately mixing the ingredients.

In terms of homogeneous mixing, it is advantageous to mix the polyorganosiloxane and the onium salt curing catalyst in advance, and then mix the silicone rubber elastomer fine particles therewith. Furthermore, if the mixing viscosity is too high, a method may be used in which each component is made into a solution or dispersion using an organic solvent and then mixed.

The treatment for imparting releasability using the silicone release agent of the present invention can be performed in the same manner as with conventional silicone release agents. That is, a release agent is applied to the object to be treated using an appropriate coating machine such as a squeeze coater, and the coating layer is heated with hot air or the like, or through an appropriate ultraviolet source such as a high-pressure mercury lamp or a metal halide lamp. This can be done by curing treatment by irradiation. Coating amount is 0.1-5g/d
is common. The heating temperature may be appropriately determined depending on the heat resistance of the object to be processed. Usually 60-200℃, especially 10
The temperature is 0 to 150°C. Further, the amount of ultraviolet ray irradiation may be appropriately determined depending on the curing characteristics of the release agent, and may be used in combination with heat treatment.

The silicone release agent of the present invention can be used, for example, to form a separator or to treat the back surface of an adhesive member such as an adhesive tape.
It 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.

The adhesive member of the present invention has a releasable film made of the silicone release agent described above on one side of a supporting base material, and an adhesive layer on the other side. Furthermore, the separator is one in which such a releasable film is provided on one or both sides of a supporting base material. There are no particular limitations on the supporting base material to be used. Generally, paper,
Plastic laminated paper, cloth, plastic laminated cloth, plastic film, metal foil, foam, etc. are used. Note that the adhesive member may be formed by a known method, such as a method of attaching an adhesive to the other surface of a supporting base material on which a releasable film has been previously provided.

Effects of the Invention The silicone release agent of the present invention has good compatibility with the onium salt curing catalyst, has excellent curability, and has excellent release properties such as excellent adhesion to the object to be treated and is difficult to fall off. Forms a film. Further, the releasable film contains fine particles of silicone-based rubber elastic material, exhibits good wettability with oil-based ink, and has excellent printability.

As a result, in the adhesive member and separator of the present invention having such a releasable film, the adhesive surface is less likely to be contaminated by the releasable film (and the adhesive force is maintained well).

Examples Reference Example 1 In a glass three-way flask equipped with a stirring blade, a thermometer, and a dropping funnel, 37.8 parts of 4-vinylcyclohexene monooxide (parts by weight, the same applies hereinafter) and polyethylene glycol allyl methyl ether (number average molecular weight 450)
A solution prepared by dissolving 137.1 parts in 500 parts of tetrahydrofuran was added, and after stirring for 30 minutes under a stream of dry nitrogen, 2.0 parts of a platinum catalyst for hydrosilylation (platinum-vinylsiloxane complex salt) was added thereto, and an additional 10 parts was added. After stirring for 4 minutes, the system
Warmed to 0°C.

Next, 100 parts of a polydimethyl methylhydrodiene siloxane copolymer with a number average molecular weight of 2000 expressed by the formula: (where p / q = 18/10 and are arranged randomly) The mixture was gradually added dropwise over about 1 hour to the stirred system heated to 40°C, and then the system was kept at 45°C and reacted for 24 hours.

The obtained reaction solution was placed in a vacuum dryer to dry the tetrahydrofuran, and then the dried product was repeatedly purified in n-hebutane to remove unreacted materials, and the dried product was purified with n-hebutane again in a vacuum dryer. was removed by drying.

As a result of infrared absorption spectrum and NMR spectrum analysis, the obtained product had the following molecular structure. Further, its number average molecular weight was 4,700.

p/r according to Reference Example 1 in the presence of 00 parts of Roblanf.
A polyorganosiloxane with a ratio of 2/1/s and a number average molecular weight of 6,300 was obtained.

Ya is -C38a-〇-+CH2CH20h-TCH3
and p/r/5=181515. In addition, in Reference Example 3, the amount of 4-vinylcyclohexene monooxide used was 7
p/r/s according to Reference Example 1 except that the amount of tetrahydrofuran used was 350 parts and polyethylene glycol allyl methyl ether was not used.
A polyorganosiloxane having a ratio of 18/1010 and a number average molecular weight of 3,200 was obtained.

Reference example 2 The amount of 4-vinylcyclohexene monooxide used was 5
5.8 parts, the amount of polyethylene glycol allyl methyl ether used is 202.5 parts, and the polydimethyl methylhydrodiene siloxane copolymer differs only in that p/q in the above formula is 15/15. Example 1: To 72 parts of the polyorganosiloxane obtained in Reference Example 1, 3 parts of an ultraviolet-reactive sulfonium salt-based curing catalyst were added and mixed thoroughly with stirring. Add 25 parts of the silicone rubber elastomer contained and stir and mix uniformly to obtain the silicone release agent (solvent-free coating type) of the present invention.
was prepared.

Next, apply the above release agent to a thickness of 120 μm using a squeeze coater.
Coat the laminated surface of Ashi's polyethylene laminated kraft paper at a coating weight of 1 g/J, and cure the release agent-coated surface by irradiating it with ultraviolet rays using an ultraviolet irradiation device equipped with a high-pressure mercury lamp. A separator was formed by processing. The amount of ultraviolet rays irradiated is 1 joule/c++
It was set as f.

Example 2 4 parts of a heat-reactive sulfonium salt-based curing catalyst was added to 76 parts of the polyorganosiloxane obtained in Reference Example 1, and the mixture was sufficiently stirred and mixed. Elastic silicone rubber having an average particle size of 5 μm and containing an epoxy group was added to the mixture. A silicone release agent (solvent-free coating type) of the present invention was prepared by adding 20 parts of the silicone release agent and stirring the mixture uniformly, and using this, a separator was obtained according to Example 1.

However, the curing treatment for the release agent coating layer was carried out by heating it in a hot air constant temperature machine at 100° C. for 10 minutes.

Example 3 In place of the polyorganosiloxane of Reference Example 1, Reference Example 2 was used.
Example 1 except that the polyorganosiloxane obtained in Example 1 was used.
A silicone release agent and separator of the present invention were obtained according to the method.

Example 4 4 parts of an ultraviolet-reactive sulfonium salt-based curing catalyst was added to 76 parts of the polyorganosiloxane obtained in Reference Example 2, and the mixture was thoroughly stirred and mixed. Elastic silicone rubber having an average particle size of 5 μm and containing an epoxy group was added to the mixture. Add 20 parts of the silicone release agent of the present invention (solvent-free coating type) by stirring and mixing uniformly.
was prepared and used to obtain a separator according to Example 1.

Comparative Example 1 A silicone release agent was prepared by adding 6 parts of an ultraviolet-reactive sulfonium salt curing catalyst to 94 parts of the polyorganosiloxane obtained in Reference Example 3 and thoroughly stirring and mixing. A similar separator was obtained.

Comparative Example 2 In place of the polyorganosiloxane of Reference Example 1, Reference Example 3 was used.
Example 1 except that the polyorganosiloxane obtained in Example 1 was used.
A silicone release agent and a separator were obtained in accordance with .

The following properties of the separators obtained in the evaluation test examples and comparative examples were investigated.

[Curability 1] Evaluation was given as ◯ when there was no stickiness in the peelable film of the separator, △ when there was a little stickiness, and × when there was large stickiness.

[Printability] Characters were written on the surface of the releasable film of the separator using a commercially available oil-based ink, and the results were evaluated as ◎ if there was no repelling at all, ○ if there was almost no repelling, △ if there was some, and × if there was significant repelling.

[Peeling force J: 20°C, 65% R, H, a commercially available adhesive tape (manufactured by Nitto Denko Corporation, Kraft Tape Nn712) with a width of 2511 IIl was applied once back and forth with a rubber roller weighing 2 dazzles on the peelable film surface of the separator. After pressing and bonding, the adhesive tape was left at 20° C. for 48 hours with a load of 50 g/cd applied. After that, the load was released and the temperature was 20℃, 65%R,)
1. The adhesive tape was then peeled off using a shopper at a speed of 300 wm/min (180°), and the force required for peeling was determined (average value of 4 samples).

[Residual adhesion rate] (Non-staining of adhesive surface) After measuring the above peeling force, the adhesive tape was coated with waterproof abrasive paper (No. 280) on a stainless steel plate (SO52TCP) at 20°C and 65% R, H. After thorough polishing and cleaning, a rubber roller weighing 2 kg was moved back and forth once to press the surface, and the surface was left to stand for 30 minutes. The force required for peeling was determined in the same manner as above. Then, the ratio of the residual adhesive force of the obtained measured value to the measured value obtained for the adhesive tape that had never been brought into contact with the releasable film surface in the same manner as above was calculated as the residual adhesive rate (average of 4 samples). value).

The results are shown in the table.

As is clear from the table, the silicone release agent of the present invention has excellent curability, and its peelable film has excellent oil-based ink printing properties and non-staining properties on the adhesive surface.

Patent applicant: Nitto Denko Corporation

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group, and It is a functional organic group, Y is a polyether polymethylene group, and m/(l+m+n) is 0.05 to 9
0%, and n/(l+m+n) is 0.5 to 90%. ) A silicone-based release agent characterized by comprising a polyorganosiloxane represented by the following formula, silicone-based rubber elastomer fine particles, and an onium salt-based curing catalyst. 2. The silicone release agent according to claim 1, which is made of a polyorganosiloxane having a number average molecular weight of 500 to 500,000 to impart solvent-free coating properties. 3. An adhesive member having a releasable film made of the silicone release agent according to claim 1 on one side of a supporting base material and an adhesive layer on the other side. 4. A separator characterized by having a releasable film made of the silicone release agent according to claim 1 on one or both sides of a supporting base material.