JPH0699672B2 - Peeling treatment agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a release treatment agent, and more specifically, in a product using an adhesive such as an adhesive tape, an adhesive label, and an adhesive sheet, the adhesive surface is overlaid. The present invention relates to a releasable treatment agent capable of imparting releasability to the back surface of a base material such as a tape or the like or the surface of a release paper.

(Prior Art) Conventionally, as a release agent used for the above purpose, a polymer compound such as an acrylic acid-based, polyester-based or polyamide-based compound having a long-chain alkyl group bonded and an organopolysiloxane-based compound have been known. It is used to form a release surface on the back surface of an adhesive tape or an adhesive sheet or on the surface of release paper. Among these, organopolysiloxane compounds are excellent in properties such as peelability and residual adhesiveness.

(Problems to be Solved by the Invention) Conventional organopolysiloxane compounds have the above-mentioned characteristics, but the peeling force is not appropriate, and high-temperature baking is required at the time of coating on a substrate. There was a problem that it could not be used for the material film. Further, there is a defect that the adhesion to the base material is insufficient depending on the base material and the base material cannot be used for many kinds of base materials.

Further, since the peelable polysiloxane compound has a small critical surface tension, it cannot be written on the peeled surface, and cissing often occurs when a pressure-sensitive or heat-sensitive adhesive is applied to the peeled surface. However, there is a problem that a good coated surface cannot be formed.

Therefore, an object of the present invention is to provide a releasable treatment agent which can be baked at a low temperature and can be applied to a thermoplastic resin film or the like.

Another object of the present invention is to have no selectivity for the substrate,
It is an object of the present invention to provide a release treatment agent capable of forming a release surface on any base material.

Still another object of the present invention is to provide a releasable treatment agent capable of forming a releasable surface on which a writable aqueous ink or oily ink can be written.

(Means for Solving Problems) The above object is achieved by the present invention described below.

That is, the present invention is a release treatment agent containing a resin having a siloxane segment, wherein the resin is a polyurethane resin containing a copolymer segment of a siloxane compound and caprolactene. is there.

(Function) By using a specific polyurethane-based resin having a siloxane segment, it is possible to form a release surface which can be baked at a low temperature and has no selectivity for a substrate, and which can be written with a pen or the like and has an appropriate release force. .

(Preferred Embodiment) Next, the present invention will be described in more detail with reference to preferred embodiments.

The polyurethane-based resin used in the present invention and mainly characterizing the present invention is obtained by reacting a polyol, a polyisocyanate, and optionally a chain extender, etc. to obtain a polyurethane-based resin. It is obtained by using a copolymer of a siloxane compound having OH and caprolactone.

Preferred examples of the active hydrogen-containing siloxane compound used in the present invention include the following compounds.

(1) Amino-modified siloxane oil (2) Epoxy-modified siloxane oil The above-mentioned epoxy compound can be used by reacting with a polyol, polyamine, polycarboxylic acid or the like so that it has active hydrogen at the terminal.

(3) Alcohol-modified siloxane oil (4) Mercapto-modified siloxane oil (5) Carboxyl-modified siloxane oil The siloxane compound having active hydrogen as described above is an example of a preferable siloxane compound in the present invention, and the present invention is not limited to these examples, and the above-exemplified compounds and other siloxane compounds are , Which are currently on the market and are easily available from the market,
Any of them can be used in the present invention. Incidentally, in the siloxane compound, a monofunctional compound can be incorporated into the polyurethane by copolymerizing with caprolactone and then reacting with the polyurethane having NCO at the terminal.

In the present invention, ε-caprolactone that is reacted with a siloxane compound having active hydrogen is represented by the following general formula.

Most preferred for the purposes of the present invention are ε-caprolactone, monomethyl-ε-caprolactone, monoethyl-ε.
-Various monoalkyl- [epsilon] -caprolactones such as caprolactone, monopropyl- [epsilon] -caprolactone and monododecyl- [epsilon] -caprolactone or two alkyl groups, both without being bound to a carbon atom in the [epsilon] -position. A dialkyl-ε-caprolactone or a carbon atom at the ε-position of the lactone ring which is respectively substituted with a different carbon atom is not di-substituted and thus another 2 or 3 carbon atom is substituted with 3 alkyl. Alkoxy-ε-caprolactones such as trialkyl-ε-caprolactone and ethoxy-ε-caprolactone substituted by groups or cycloalkyl-ε-caprolactones such as cyclohexyl, phenyl- and benzyl-ε-caprolactone,
And aryl-ε-caprolactone and aralkyl-ε-caprolactone.

The reaction between the siloxane compound and the caprolactone is carried out by mixing the two, and preferably using a suitable catalyst under a nitrogen stream, and reacting at a temperature of 150 to 200 ° C. for several hours to several tens of hours to obtain a siloxane-modified polysiloxane. A caprolactone copolymer is obtained. Both can be reacted at any reaction ratio, but for the purpose of the present invention, it is preferable to react at a ratio such that the siloxane segment accounts for 10 to 80% by weight in the copolymer. If the amount of the siloxane compound used is too small, the non-adhesiveness, blocking resistance, etc. of the finally obtained polyurethane resin will be insufficient, while if it is too large, the flexibility of the obtained polyurethane resin will decrease. Not preferable.

Further, an intermediate obtained by reacting the copolymer as described above with a polyisocyanate as described below so that at least one of the hydroxyl group of the copolymer or the isocyanate group of the polyisocyanate group remains, for example, a bifunctional copolymer It is also possible to use a product obtained by reacting the polymer with a polyfunctional polyisocyanate in a rich isocyanate group or, conversely, an intermediate obtained by reacting the copolymer with a rich reactive group.

Further, polyester polyols obtained by reacting a copolymer with polycarboxylic acid can be used in the same manner.

As the polyol that may be used in combination with the siloxane-modified polycaprolactone copolymer, any conventionally known polyol for polyurethane can be used. For example, a terminal group is preferably a hydroxyl group, and a molecular weight of 300 to 300 is preferable.
4,000 polyethylene adipate, polyethylene propylene adipate, polyethylene butylene adipate, polydiethylene adipate, polybutylene adipate, polyethylene succinate, polybutylene succinate, polyethylene sebacate, polybutylene sebacate, polytetramethylene ether glycol, poly-ε-caprolactone Examples include diols, polyhexamethylene adipate, carbonate polyols, polypropylene glycols, and the like, and those containing a suitable amount of polyoxyethylene chains in the above polyols.

As the organic polyisocyanate, any conventionally known one can be used, but, for example, as preferred ones, 4,4′-diphenylmethane diisocyanate (MDI), hydrogenated MDI, isophorone diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, etc., or organic polyisocyanates thereof As a matter of course, a urethane prepolymer obtained by reacting a low molecular weight polyol or polyamine with a terminal isocyanate to obtain a urethane prepolymer can be used.

As the chain extender, any conventionally known one can be used, but preferred examples include ethylene glycol, propyne glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, ethylenediamine, 1 , 2-propylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, decamethylenediamine, isophoronediamine, m-xylylenediamine, hydrazine, water and the like.

Among the polyurethane-based resins obtained from the materials as described above, particularly preferable one is that the siloxane-caprolactone copolymer segment is about 10 in the polyurethane-based resin molecule.
If the copolymer is less than about 10% by weight, the non-adhesiveness, which is the intended purpose of the present invention, the expression of blocking resistance, etc. becomes insufficient, while the amount of 80% by weight is 80% by weight. When it exceeds the above range, the flexibility of the obtained polyurethane resin becomes insufficient, which is not preferable.

The preferred ones have a molecular weight of 20,000 to 500,000, and the most preferred ones have a molecular weight of 20,000 to 250,000.

In the present invention, the above copolymer and polyisocyanate are reacted in an isocyanate-rich state to give a polyurethane resin having at least one free isocyanate group, which is used for forming another film. It can also be used as a modifier thereof in combination with a resin.

The polyurethane resin containing the siloxanecaprolactone copolymer segment as described above can be easily obtained by a conventionally known production method. These polyurethane-based resins may be prepared without a solvent or may be prepared in an organic solvent, but in the process, by preparing in an organic solvent, the resulting solution can be directly used for various purposes. It is advantageous because it can be used.

Preferred as such an organic solvent are methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate,
Propyl formate, methyl acetate, ethyl acetate, butyl acetate and the like, and also acetone, cyclohexane, tetrahydrofuran, dioxane, methanol, ethanol, isopropyl alcohol, butanol, toluene, xylene,
Dimethylformamide, dimethylsulfoxide, perchlorethylene, trichloroethylene, methylcellosolve, butylcellosolve, cellosolve acetate and the like can also be used.

The polyurethane-based resin as described above has excellent non-adhesiveness and blocking resistance, but is easily soluble in various organic solvents and can form an excellent flexible film.

The above-mentioned polyurethane resin solution itself is the release treatment agent of the present invention, and it can be used as it is, and further various additives, for example, known additives such as colorants, crosslinking agents, stabilizers, fillers, etc. Can be added arbitrarily.

In particular, a conventionally known releasing agent as one kind of additives, for example, wood powder, talc, silica, boron nitride, alumina, polyethylene resin powder, benzoguanamine resin powder, silicone resin powder, melamine resin powder, fluororesin powder,
Phenol resin powder and the like can be added in an amount of 0 and 200 parts by weight per 100 parts by weight of the polyurethane resin. Further, as the additive, a general thermoplastic or thermosetting resin can be used together.

(Effects) According to the present invention as described above, by using a polyurethane resin having a siloxane segment, it is possible to perform low-temperature baking, no selectivity for a substrate, and writing with a pen or the like, and a suitable peeling force. A surface can be formed.

(Example) Next, the present invention will be described more specifically with reference to Reference Examples, Examples, and Comparative Examples. In the text, parts and% are based on weight.

Reference example 1 (K is a value at which the molecular weight becomes 980.) 310 parts of ε-caprolactone and the above structure (1) are contained in a reactor equipped with a stirrer, a thermometer, a nitrogen gas introducing pipe, and a reflux condenser. Alcohol-modified siloxane oil 15
0 parts and 0.05 parts of tetrabutyl titanate were charged and reacted at 180 ° C. for 10 hours under a nitrogen stream to obtain a polysiloxane-polyester copolymer having a hydroxyl value of 37, an acid value of 0.40 and a molecular weight of 3,030.

The above copolymer 150 and 27 parts of 1,4-butanediol were mixed with 200
Dissolve in a mixed solvent of 100 parts of methyl ethyl ketone and 100 parts of dimethylformamide, and stir at 60 ° C. with good stirring.
Part of hydrogenated MDI dissolved in 188 parts of dimethylformamide was gradually added dropwise, and after completion of the addition, reaction was carried out at 80 ° C. for 6 hours to obtain a polyurethane resin solution used in the present invention.
This solution is very transparent with 35% solids at 35,500 cps
It had a viscosity of (25 ° C).

Reference Example 2 75 parts of the copolymer of Reference Example 1, 75 parts of polybutylene adipate (hydroxyl value 56.0, acid value 0.40, molecular weight 2,000) and 27 parts of 1,4-butanediol were mixed with 200 parts of methyl ethyl ketone and 150 parts.
Part of dimethylformamide dissolved in a mixed solvent, 60
A mixture of 90 parts of MDI dissolved in 146 parts of dimethylformamide was slowly added dropwise while stirring well at ℃.
The reaction was performed at 6 ° C. for 6 hours to obtain a polyurethane resin solution used in the present invention. This solution is very transparent and solid
It had a viscosity of 31,200 cps (25 ° C) at 35%.

Reference example 3 (K is a value at which the molecular weight becomes 1,900.) A reactor equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, and a reflux condenser has 166 parts of ε-caprolactone and the above structure (2). Alcohol-modified siloxane oil 15
Charge 0 parts and 0.04 parts of tetrabutyl titanate, react for 10 hours at a temperature of 180 ° C under a nitrogen stream, and have a hydroxyl value of 28,
A polysiloxane-polyester copolymer having an acid value of 0.35 and a molecular weight of 4,010 was obtained.

20 parts of 150 parts of the above copolymer and 27 parts of 1,4-butanediol are added.
Dissolve it in a mixed solvent of 0 parts of methyl ethyl ketone and 100 parts of dimethylformamide and stir well at 60 ° C. 88
One part of hydrogenated MDI dissolved in 192 parts of dimethylformamide was gradually added dropwise, and after completion of the addition, reaction was carried out at 80 ° C. for 6 hours to obtain a polyurethane resin solution used in the present invention.
This solution is very transparent and has a solid content of 35% at 31,200 cps.
It had a viscosity of (25 ° C).

Reference Example 4 75 parts of the copolymer of Reference Example 3, 75 parts of polyethylene adipate (hydroxyl value 56.0, acid value 0.28, molecular weight 2,000) and 27 parts of 1,4-butanediol were mixed with 200 parts of methyl ethyl ketone and 150 parts of dimethylformamide. Dissolved in a mixed solvent of 60 ℃
A solution of 93 parts of MDI dissolved in 151 parts of dimethylformamide was slowly added dropwise with thorough stirring at 80 ° C after the addition was completed.
Was reacted for 6 hours to obtain a polyurethane resin solution used in the present invention. This solution is very transparent and has a solid content of 35
It had a viscosity of 40,500 cps (25 ° C) in%.

Reference example 5 (M is a value at which the molecular weight becomes 1,600.) A reactor equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, and a reflux condenser has 178 parts of ε-caprolactone and the above structure (3). Amino-modified siloxane oil (150 parts) and tetrabutyl titanate (0.04 parts) were charged and reacted under a nitrogen stream at a temperature of 180 ° C for 10 hours to give a hydroxyl value of 32 and an acid value of 32.
A polysiloxane-polyester copolymer having a molecular weight of 0.28 and a molecular weight of 3,500 was obtained.

20 parts of 150 parts of the above copolymer and 27 parts of 1,4-butanediol are added.
It is dissolved in a mixed solvent of 0 part of methyl ethyl ketone and 100 parts of dimethylformamide, and stirred at 60 ° C. with good stirring.
One part of MDI dissolved in 187 parts of dimethylformamide was gradually added dropwise, and after completion of the addition, reaction was carried out at 80 ° C. for 6 hours to obtain a polyurethane resin solution used in the present invention. This solution is very transparent and has 35% solids and 35,600 cps (25%
C.).

Comparative Reference Example 1 (Synthesis of Conventionally Known Polyurethane Resin) With 150 parts of polybutylene adipate having an average molecular weight of about 2,000
10 parts of 1,4-butanediol was dissolved in a mixed organic solvent consisting of 120 parts of methyl ethyl ketone and 130 parts of dimethylformamide, and 47 parts of water-added MDI was dissolved in 135 parts of methyl ethyl ketone. A polyurethane resin solution was obtained in the same manner as in Reference Example 1.

The solid content of this solution was 35% and had a viscosity of 14,500 cps (25 ° C).

Comparative Reference Example 2 Shin-Etsu Chemical Co., Ltd. polysiloxane resin (trade name; K
S-841) 100 parts and accompanying solvent (trade name; PL-7)
1 part was dissolved in 1,000 parts of toluene to obtain a polysiloxane resin coating solution.

Examples 1 to 5 and Comparative Examples 1 to 2 The following release treatment agents were used to obtain a 100% modulus of 60 kg / cm ² and a thickness.
Solid content 0.6 g on one side of 50 μm polyvinyl chloride film
The sample was evenly coated so that the coating amount was / m ² , and dried by heating at 80 ° C. for 30 seconds to prepare a sample having a peelable coating layer. still,
When the temperature was raised to a high temperature (100 ° C or higher), the polyvinyl chloride film was softened and could not maintain its shape as a film.

Acrylic adhesive tape (made by Sekisui Chemical Co., Ltd.) with a width of 20 mm was pressure-bonded onto the coated substrate prepared in this way using a rubber roller with a weight of 2 kg, and after 1 day at normal temperature (20 ° C, humidity 52%) and high temperature (40 ° C, The peel strength, the residual adhesive strength, the residual adhesive strength retention rate, the peeling property of the peelable coating layer, and the writability with the magic ink after standing for 3 days at a humidity of 90% or more) were measured and the results are shown in Table 1 below. .

Example 1 Resin solution of Reference Example 1 100 parts Methyl ethyl ketone 250 parts Example 2 Resin solution of Reference Example 2 100 parts Fluororesin powder (Daikin Industries; Lubron L-2) 5 parts Methyl ethyl ketone 250 parts Resin of Example 3 Reference Example 3 Solution 100 parts Coronate L (addition product of trimethylolpropane and TDI) 2 parts Methyl ethyl ketone 250 parts Resin solution of Example 4 Reference Example 4 100 parts Coronate L 2 parts Silicone resin powder (Toshiba Silicone, Tospearl 12
0) 5 parts methyl ethyl ketone 250 parts Example 5 Resin solution of Reference Example 5 100 parts Methyl ethyl ketone 250 parts Comparative Example 1 Resin solution of Comparative Reference Example 1 100 parts Silicone oil (SH-200, Toray Silicone) 5 parts Methyl ethyl ketone 250 parts Comparative Example 2 100 parts of resin solution of Comparative Reference Example 2 Each evaluation was performed according to the following.

Peeling force: Stick an adhesive tape with a width of 20 mm on the peelable coating layer,
After storing at 40 ℃ under 20g / cm ² load for 24 hours, 300mm /
The force (g) required for peeling by pulling at an angle of 180 ° at a speed of minute was measured (20 ° C).

Residual adhesive strength: Adhere the adhesive tape after measuring the peeling force to a stainless steel plate # 280, make one reciprocation with a 2 Kg tape roller, and after 30 minutes pull it at an angle of 180 ° at a speed of 300 mm / min to peel it off. The force (s) required for was measured (20 ° C).

Residual adhesive strength retention rate: Indicates the% of residual adhesive strength when a clean adhesive tape that has not been subjected to peeling resistance is adhered to a stainless steel plate # 280 and the adhesive strength (320g / 20mm) to the stainless steel plate is 100%. ing.

Detachability; The strippable coating layer is subjected to a removability test after the gauze is reciprocated once with a load of 50 g / cm ^{2 on} the strippable coating layer.

Writability with Magic Ink: Characters were written with a commercially available oil-based Magic Ink on the peelable coating layer, and the presence or absence of ink repellency during writing was examined.

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Claims (5)

[Claims] 1. A peeling treatment agent containing a resin having a siloxane segment, wherein the resin comprises a polyurethane resin containing a copolymer segment of a siloxane compound and caprolactone. 2. The peeling treatment agent according to claim 1, wherein the siloxane segment accounts for 10 to 80% by weight in the copolymer. 3. A copolymerized segment 10 to 10 in polyurethane.
The release treatment agent according to claim 1, which accounts for 80% by weight. 4. The peeling treatment agent according to claim 1, which further contains a peeling substance. 5. The peeling treatment agent according to claim 1, which is an organic solvent solution.