JPS61163982A - Solvent-resistant peelable treating agent - Google Patents

Abstract

PURPOSE:To obtain a peelable treating agent which has excellent solvent resis tance and is inexpensive, by blending a fluorinated alcohol-modified polyorganohydrosiloxane with a specified polydiorganosiloxane. CONSTITUTION:A peelable treating agent consists of a polyoprganohydrosiloxane contg. at least two H atoms attached to the Si atom per molecule, modified with a fluorinated alcohol of the formula (wherein n is 1-4) and a polydiorganosiloxane contg. at least two vinyl groups attached to the Si atom per molecule. As the polyorganohydrosiloxane to be modified with the alcohol, those having a viscosity of 10-10,000cp at 25 deg.C are prefered from the viewpoints of the reactivity with said alcohol and well-balanced prperpies between the peelability and the adhesion of the resulting treating agent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a silicone-based solvent-resistant release treatment agent modified with a fluorine-containing alcohol and suitable as a back treatment agent.

[Conventional technology]

Adhesive tapes placed in the distribution process as rolled up products usually have a releasable treatment layer made of a backing agent on the back side of the base material coated with an adhesive to make the back side non-adhesive. It is provided.

Conventionally, thermosetting silicone compounds, chain alkyl compounds, and the like have been known as back treatment agents or release treatment agents.

[Problems to be solved]

However, conventional stripping agents made of silicone-based or long-chain alkyl-based compounds have poor resistance to organic solvents such as toluene, benzene, and trichlene.
For example, if a masking tape made of a paper base material to which this masking tape is applied is attached to a car body, etc., and a paint containing an organic solvent is sprayed from the back side and then heated and dried, the tape may come into contact with an organic solvent. The peelable treatment layer is attacked by an organic solvent and swells or dissolves, and the solvent also penetrates the base material and dissolves the adhesive, causing problems such as a residue. .

On the other hand, fluorine-based compounds have been proposed as solvent-resistant compounds, but they are expensive and unsatisfactory as they are practically unsuitable as stripping agents that are consumed in relatively large quantities.

[Means for solving problems]

As a result of extensive research to overcome the above problems and develop a stripping agent that is both excellent in solvent properties and inexpensive, the present inventors have developed a special polysiloxane modified with fluorine-containing alcohol. It was discovered that the purpose could be achieved by using a silicone-based peeling treatment agent containing a silicone-based compound, and
The present invention has been accomplished.

That is, the present invention is directed to hydrogen atoms modified with a fluorine-containing alcohol expressed by the general formula % (for reference, n is an integer of 1 to 4), with at least a silicon atom in the molecule. A polyorganohydrosiloxane having two.

At least 2 silicon atoms directly connected to a vinyl group in the molecule
The object of the present invention is to provide a solvent-resistant peeling treatment agent comprising a polydiorganosiloxane.

The polyorganohydrosiloxane used in the present invention is one modified with a fluorine-containing alcohol expressed by the general formula H+CFg-CF2CH20H (where n is an integer from 1 to 4).
"This modified product can be obtained by reacting, for example, a polyorganohydrosiloxane with the fluorine-containing alcohol in an amount of 0.1 to 5 times its weight, preferably 0.3 to 8 times its weight. The general reaction method is to gradually drop a K-containing alcohol into a polyorganohydrosiloxane under heating (50 to 90° C.).

Further, the polyorganohydrosiloxane used in the present invention has two silicon atoms or #i8 or more silicon atoms directly connected to hydrogen atoms in the molecule. Specifically, rKF made of polymethylhydrosiloxane compounds etc.
-99J (product name; manufactured by Shin-Etsu Chemical Co., Ltd.), “5H-1107
J (Product name: Tone Silicone Co., Ltd.).

The polyorganohydrosiloxane before modification with the fluorine-containing alcohol has a viscosity of 10 to 10,000 centipoise at 25°C, and <20 centipoise.
~8000 centipoise.

It is preferably used in terms of physical properties such as reaction treatment with fluorine-containing alcohol and puffiness of the resulting releasable treatment agent with respect to releasability and adhesive strength.

On the other hand, polydiorganosiloxanes having two or eight or more silicon atoms directly connected to vinyl groups in one molecule are used. Its viscosity at 25°C is 100-5000 centipoise, especially 150-4
It is preferably used in view of the physical properties of the releasable treatment agent that yields a polydiorganosiloxane of 0.000 centipoise. A typical example is:

Vinyl-modified dimethylpolysiloxane, etc. can be used.

The release treatment agent of the present invention is composed of a mixed system of the above-mentioned fluorine-containing alcohol-modified polyorganohydrosiloxane and polydiorganosiloxane. The mixing ratio of the polyorganohydrosiloxane to 1.1 to 2 times the weight of the polydiorganosiloxane is suitable from the viewpoint of melting solvent properties and other physical properties of the resulting stripping agent. Of course, it is not limited to this.

The release treatment agent of the present invention is usually prepared by adding a curing catalyst to a mixed system of the above-mentioned fluorine-containing alcohol-modified polyalkanohydrosiloxane and polydiorganosiloxane, and is used in the adhesive tape in the form of an acid combination that forms an addition reaction type silicone. It is applied to tape-shaped or sheet-shaped base materials for forming etc.

At that time, a known silicone forming catalyst is used as the curing catalyst. Among these, platinum-based catalysts such as platinum or chloroplatinic acid or chloroethylene platinum complexes are preferably used. The appropriate amount of the curing catalyst added is 2 to 20 parts by weight per 100 parts by weight of the total solids of the polyorganohydrosiloxane' and polydiorganosiloxane.

Then, the releasable treatment agent of the present invention is made into a solution using an appropriate solvent such as toluene, and the solution is applied to a base material and dried by heating to form a releasable treated layer.

〔Effect of the invention〕

According to the present invention, a releasable treated layer with excellent solvent resistance can be formed. Incidentally, a masking tape having a releasable treatment layer formed using the releasable treatment agent of the present invention was applied to the body of an automobile, and after spraying urethane paint, which is an automobile paint, on the masking tape, it was heated at 80"C for 80 minutes. Even when the masking tape is peeled off from the car body after the semi-drying process, no glue or sticky substance is transferred to or remains on the car body side.As a result, the car body is not contaminated with glue.

Thus, it has excellent solvent barrier properties.

1. According to the present invention, the removability evaluated by the unwinding force of the rolled up adhesive tape and the puffiness of the adhesive tape to the base material evaluated by the transferability to the adhesive side of the adhesive tape. A treated layer with excellent releasability can be formed.

〔Example〕

Example 1 50 g of polyorganohydrosiloxane (KF-99) =
80f of fluorine-containing alcohol expressed as ei=h÷ was gradually added to the solution, and after the dropwise addition was completed, the reaction was carried out for 2 hours (at 70°C) to complete the reaction.

The resulting reaction product 100F has a viscosity at 25°C.
40 g of vinyl-modified polydimethylsiloxane having 5 vinyl groups directly bonded to silicon atoms in the 11020 centipoise molecule and 8F chloroplatinic acid were added.

Furthermore, toluene was added to obtain a stripping agent having a concentration of 10% wax (solid content).

Next, apply this releasable treatment agent in an amount of 1.5 mm to one side of Japanese paper that has been sealed with a rubber-based undercoat. A paper tape was prepared by coating the tape so that it was of/vf and applying a rubber adhesive to the other side.

The peel strength and solvent resistance of the paper tapes were evaluated by the following method. The results are shown in the table.

[Peeling force]

Polyester adhesive tape &81B (manufactured by Nitto Denki Kogyo Co., Ltd.) was attached by moving a 2 kg loaf back and forth once on the surface of the paper tape provided with the releasable treatment layer, and when the adhesive tape was peeled off after heating at 70°C for 24 hours. The peeling force was examined using a Tensilon tensile tester (manufactured by Shimadzu Corporation) at 20° C. and a tensile speed of 800 tm/min.

[Solvent resistance]

A paper tape was pasted on a clean iron plate via an adhesive, and then a urethane paint dissolved with thinner was sprayed from the releasable treated layer side, heated at 80°C for 30 minutes, and dried. Next, after cooling it to room temperature, remove the paper tape and check whether there is any adhesive left on the iron plate. If there is no adhesive left at all, 0. A case in which a very small amount of alkalinity remained with no substantial effect was evaluated as ○, and a case in which a significant amount remained was evaluated as ×.

Example 2 Polyorganohydrosiloxane (i9) (-1107)
50f.

H(-CF2- CF2-+rC820H2Of, 25
Vinyl-modified polydimethylsiloxane 50f with a viscosity of 5007 mm at °C, chloroplatinic acid 51 (Example 2),
Matake KF-99509, HCF2-CF2-CH20H
Vinyl modified polydimethylsiloxane 86f with a viscosity of 800 centipoise at 20F and 25C! , chloroplatinic acid Tf
(Example 8), or KF-99,50f, H+CF2
-CF2+r CH20H100f.

vinyl modified dimethylpolysiloxane 60F with a viscosity of 2200 centipoise at 25°C;
A releasable treatment agent was prepared in the same manner as in Example 1 using chloroplatinic acid 10f (Example 5), a one-paper tape was prepared, and its peeling force and solvent resistance were examined. Please show the results in the table.

Comparative Example I KF-99, 100fh Vinyl modified polydimethylsiloxane 60f with a viscosity of 800 centipoise at 25°C.

A releasable treatment agent was prepared in the same manner as in Example 1 using chloroplatinic acid 4f, and a paper tape was prepared to examine its releasability and solvent resistance. The results are shown in the table.

Comparative Example 2 KF-99, 100f, viscosity at 25°C is 2200
Centipoise vinyl modified polydimethylsiloxane 90
f.

A releasable treatment agent was prepared in the same manner as in Example 1 using chloroplatinic acid 5f, and a paper tape was prepared to examine its releasability and r# solvent properties. The results are shown in the table.

From the margin table below, the release agent using polyorganohydrosiloxane modified with fluorine-containing alcohol of the present invention is compared to that using polyorganohydrosiloxane not modified with fluorine-containing alcohol.

It can be seen that the solvent resistance is significantly improved.

It is also seen that the peelable treatment agent of the present invention has a peeling rate of -1 bite which is sufficient for practical use.

Claims (1)

[Scope of Claims] 1. Silicon with directly bonded hydrogen atoms modified with a fluorine-containing alcohol represented by the general formula H-(CF_2-CF_2)-_nCH_2OH (where n is an integer from 1 to 4) A solvent-resistant release treatment agent comprising a polyorganohydrosiloxane having at least two atoms in the molecule and a polydiorganosiloxane having at least two silicon atoms directly bonded to vinyl groups in the molecule. 2. The processing agent according to claim 1, wherein the polyorganohydrosiloxane before modification with a fluorine-containing alcohol has a viscosity of 10 to 10,000 centipoise at 25°C. 3. The processing agent according to claim 1, wherein the polydiorganosiloxane has a viscosity of 100 to 5000 centipoise at 25°C. 4. The processing agent according to claim 1, which contains 2 to 20 parts by weight of a curing catalyst per 100 parts by weight of the total solids of the modified polyorganohydrosiloxane and polydiorganosiloxane.