JPH03166281A - Releasant and tack member and separator - Google Patents

Abstract

PURPOSE:To provide a highly heat-resistant releasant good in oily ink printability, also excellent in the preservability for the peel force and residual adhesive force after left under a high-temperature atmosphere, comprising a polyorganosiloxane having in its side chain specific fluorine-contg. organic group(s). CONSTITUTION:The objective silicone-based releasant comprising a polyorganosiloxane having in its side chain fluorine-contg. organic group(s) with at least its terminal represented by perfluorohydrocarbon unit.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a silicone release agent forming a film having excellent oil-based ink printability and heat resistance, and to adhesive members and separators having such a film.

PRIOR ART TECHNOLOGIES AND PROBLEMS There is a strong demand for the ability to print addresses, etc. with oil-based ink in a good manner on treated films of release agents applied to adhesive tapes, separators, etc. in order to facilitate peeling from adhesive surfaces. In addition, there are strong demands for heat resistance, such as ensuring that the wound material cannot be unwound even in a high-temperature environment and that the thermal characteristics of peeling performance are stable.

Conventionally, silicone-based release agents made of polydimethylsiloxane have been known.

However, there was a problem that printing was not possible because the treated film repels oil-based ink. There is also a proposal to add oil-based ink printability by blending finely powdered silica or ethyl cellulose (JP-A-59-126475, JP-A-59-147).
Publication No. 048). However, when finely powdered silica is added, the curing properties of the release agent are significantly reduced, causing a problem in which it is difficult to form a satisfactory treated film.

With long-chain alkyl release agents, the treated film has poor heat resistance and cannot be replaced with silicone release agents.

Means for Solving the Problems The present inventor has conducted extensive research to overcome the above problems and develop a silicone-based release agent that forms a treated film with excellent oil-based ink printing performance and heat resistance. The inventors have discovered that the object can be achieved by using a polyorganosiloxane having a perfluorinated fluorine-containing organic group at the end of the chain, and have completed the present invention.

That is, the present invention provides a release agent characterized in that at least the terminal portion thereof is made of a polyorganosiloxane having a fluorine-containing organic group in the side chain formed by a fluorine-containing hydrocarbon group unit, and a release agent having the above-mentioned release agent on one side of a supporting substrate. An adhesive member characterized by having a treated film made of a release agent and an adhesive layer on the other side, and a separator characterized by having a treated film made of the release agent on one or both sides of a supporting base material. It provides:

Effect By using a polyorganosiloxane having a fluorine-containing organic group in its side chain, at least the end portion of which is formed by a perfluorohydrocarbon group unit, it has excellent compatibility with oil-based inks and excellent thermal stability in peeling performance. A silicone-based treated film is formed.

Exemplification of structural elements of the invention The stripping agent of the present invention has at least a terminal portion containing a perfluorohydrocarbon group unit, such as an addition reaction product obtained by hydrosilylation of β-(perfluorooctyl)ethyl acrylate and hydrogen methylsiloxane. A polyorganosiloxane having a fluorine-containing organic group formed in a side chain is used. The fluorine-containing organic group forming the side chain usually consists of a long chain organic group having 3 or more carbon atoms, particularly 5 to 50 carbon atoms, and may have a branched chain. Further, the fluorine-containing organic group has at least a perfluorohydrocarbon group unit such as a trifluoromethyl group unit or a pentafluoroethyl group unit at the long chain terminal portion thereof. The number of carbon atoms in the perfluorohydrocarbon group unit is usually 1 to 30.

The above polyorganosiloxane can be prepared, for example, by a method of polymerizing a siloxane monomer having the fluorine-containing organic group, a method of introducing the fluorine-containing organic group into the side chain of the polyorganosiloxane, and the like. The introduction of the fluorine-containing organic group into the siloxane monomer or polyorganosiloxane is carried out by combining a functional unit such as a C═C bond that reacts with the SiH unit with the carbonization of the fluorine-containing organic group, such as the above-mentioned β-<perfluorooctyl>ethyl acrylate. This can be carried out by reacting a compound having a hydrogen group unit by hydrosilylation or the like.

The release agent of the present invention is a polyorganosiloxane having a fluorine-containing organic group in a side chain prepared in a coatable state. Therefore, if the viscosity of the polyorganosiloxane used is high, it may be diluted with a solvent or the like. In addition, if the molecular weight of the polyorganosiloxane used is so small that the treated film does not exhibit satisfactory heat resistance, the composition is prepared to allow curing treatment.

As a method for preparing a release agent that can be cured, a known method for curing polyorganosiloxane can be applied.
The method of adding a crosslinking agent is preferable from the viewpoint of ease of preparation and ease of curing. The amount of crosslinking agent added is determined appropriately depending on the molecular weight of the polyorganosiloxane used in combination, etc.
Generally, the amount is 0.1 to 10 mol per crosslinking functional unit in the polyorganosiloxane. An example of a crosslinking method using a crosslinking agent is =si}! Examples include crosslinking reaction methods such as hydrosilylation between a unit and a functional unit such as a C═C bond that reacts with the unit. Particularly, an addition reaction method via =si}1 unit and C=C bond is preferable from the viewpoint of curing processability. Specific examples of crosslinking agents include vinyl methylsiloxane, but the crosslinking agent contains
The types of functional units involved in crosslinking, such as H units and C═C combinations, are as follows:
It may be any one that corresponds to the crosslinking-involved functional unit contained in the polyorganosiloxane.

When the release agent has a composition that is cured by an addition reaction method via the above-mentioned SiH units and C═C bonds, a platinum-based catalyst is usually used in combination. In order to inhibit the reaction before use, a reaction inhibitor such as an acetylene compound, an oxime compound, an organic phosphorus compound, an organic nitrogen compound, etc. is added as necessary. When preparing the release agent, other appropriate additives may be used in combination.

The releasability imparting treatment using the release agent of the present invention can be performed by a known method. For example, a release agent is applied to the object to be treated in an amount of about 0.05 to log/j using an appropriate application method such as a squeeze coater, and the applied layer is dried or cured by heat treatment. Examples include a method of shaping a treated film.

The heating temperature is appropriately determined depending on the heat resistance of the object to be treated, etc., but is usually 60 to 200°C.

The release agent of the present invention is preferably used, for example, 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 in the formation of a separator or in the treatment of the back side of an adhesive member such as an adhesive tape.

The adhesive member of the present invention has the above-mentioned treated film on one side of a supporting base material and has an adhesive layer on the other side. Moreover, the separator has such a treated film on one or both sides of a supporting base material.

There are no particular limitations on the support base used. Generally, paper, plastic laminated paper, cloth, plastic laminated cloth, plastic film, metal foil, etc. are used.

Note that the adhesive member may be formed by a known method such as applying an adhesive to the other surface of a support base material on which a treated film has been previously provided.

Effects of the Invention Since the release agent of the present invention is made of polyorganosiloxane having a terminal perfluorinated fluorine-containing organic group, the treated film has excellent release performance, exhibits good printability with oil-based inks, and is heat resistant. It exhibits thermal properties with excellent and stable peeling performance.

As a result, according to the adhesive member and separator of the present invention having such a treated film, the adhesive surface is not contaminated, the adhesive force is maintained well, and when the wound product is placed in a high temperature atmosphere, You can also rewind smoothly.

Examples Reference Examples 20 parts (parts by weight, hereinafter the same) of hydrogen methylsiloxane having a number average molecular weight of 1600 represented by the above formula,
β-(perfluorooctyl)ethyl acrylate 80
and 0.5 parts of a vinylsiloxane complex of chloroplatinic acid were placed in a flask equipped with a cooling tube, a stirring blade, and an inert gas introduction tube, and reacted at 50°C for 4 hours with stirring while purging with dry nitrogen. Thereafter, the mixture was aged at 70° C. for about 2 hours to prepare a polyorganosiloxane having a terminal perfluorinated fluorine-containing organic group in the side chain. ...Infrared absorption spectrum analysis of the SiH unit confirmed that the addition reaction of β-(perfluorooctyl)ethyl acrylate was almost quantitatively completed.

Example 12 parts of vinylmethylsiloxane having a number average molecular weight of 400 represented by the above formula, 88 parts of a polyorganosiloxane having a perfluorinated fluorine-containing organic group in the side chain obtained in Reference Example, methylethylkatosim A stripping agent of the present invention was prepared by adding 1 part of a reaction inhibitor and 0.5 part of a vinylsiloxane complex of chloroplatinic acid and thoroughly stirring and mixing.

Next, apply the above release agent to a thickness of 38 μm using a squeeze coater.
0.5g/n on polyester film? This was coated uniformly at a ratio of 1, and then heated and cured in an oven at 120° C. for 3 minutes to obtain a ceviel coat.

Comparative Example 1 A separator was obtained in the same manner as in Example except that a release agent made of addition reaction type heat cure silicone (manufactured by Shin-Etsu Chemical Co., Ltd.: KNS305) was used.

Comparative Example 2 A long chain alkyl release agent (Japanese Patent Publication No. 7333/1983) consisting of a 1% by weight toluene solution of polyvinyl/N-octadecylcarnocomate was coated onto a 38 μm thick polyester film using a wire coater. Apply uniformly at a rate of 0.5 g/d based on
A separator was obtained by heating and drying in an oven for 3 minutes.

Comparative Example 3 A polyester film having a thickness of 38 μm was used as a separator without being treated with a release agent.

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

[Printability 1: Use a commercially available oil-based ink pen to write on the surface of the release agent-treated film on the separator (film surface in Comparative Example 3); write this character and rate it from 5 (no \ no cissing) to 1 (severe cissing) depending on the degree of cissing. Evaluated in stages.

[Peeling force J] After applying the adhesive side of a commercially available adhesive tape (manufactured by Nitto Denko Corporation, polypropylene-based tape NQ375) with a width of 25 mm to the release agent-treated film surface (film surface in Comparative Example 3) of the separator, A rubber roller having a weight of 2 mm was moved back and forth once to perform pressure bonding. Next, it was left in an oven at 80°C for 7 days, and then heated at 20°C and 65% R. H. The adhesive tape was then peeled off from the tape (180 degrees beer, peeling speed 300 m/min) and the force required for peeling was determined.

[Residual adhesion rate 1 After measuring the above peeling force, the adhesive tape was heated to 65% at 20°C.
R. H. The sample was attached to the cleaning surface of a stainless steel plate (SUS304) and pressed by moving a rubber roller weighing 2 kg back and forth once, and then left for 30 minutes.The force required for peeling was determined in the same manner as above. Then, the ratio of the residual adhesive strength of the obtained measured value to the measured value obtained for the adhesive tape that had not been brought into contact with the surface of the film treated with the release agent in the same manner as described above was calculated as the residual adhesive rate.

The results are shown in the table. Note that the numerical value is the average value of 4 samples.

As is clear from the table, the treated film made of the release agent of the present invention has excellent printability with oil-based inks, excellent peeling strength and retention of residual adhesive strength after exposure to high temperature atmosphere, and good heat resistance. have.

Claims (1)

[Scope of Claims] 1. A stripping agent characterized in that at least the terminal portion thereof is made of a polyorganosiloxane having a fluorine-containing organic group formed from a perfluorohydrocarbon group unit in a side chain. 2. An adhesive member having a treated film made of the release agent according to claim 1 on one side of a supporting base material and an adhesive layer on the other side. 3. A separator characterized by having a treated film made of the release agent according to claim 1 on one or both sides of a supporting base material.