JPH10338896A - Release agent for self-adhesive tapes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a release agent which provides excellent printability and release characteristics by using, as the main ingredient, a high-molecular compd. having a specified wt. average mol.wt. and comprising pseudocrosslink structure parts and elastomer structure parts in a specified wt. ratio. SOLUTION: This agent is prepd. by compounding 100 pts.wt. high-molecular compd. having a wt. average mol.wt. of 10,000-500,000 and comprising 20-90 wt.% pseudocrossllink structure parts and 80-10 wt.% elastomer structure parts with 0.1-10 pts.wt. lubricant (e.g. liq. paraffin). The pseudocrosslink structure part is e.g. a polyethylene chain or a polystyrene chain and plays a roll of crosslink points, increasing the cohesive power of a release agent film, improving the heat resistance, and reducing the interaction with a self-adhesive to reduce the peeling power. A carbon-carbon double bond chain or an ethylene-propylene copolymer chain is pref. as the elastomer structure part and, exhibiting a low interaction with a self-adhesive, is favorable for light and smooth peeling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a release treatment agent for adhesive tapes, that is, a back surface treatment of adhesive tapes such as adhesive tapes and adhesive labels, and a method for removing the above-mentioned adhesive tapes. The present invention relates to a release treatment agent used for forming a separator for protecting an adhesive surface.

[0002]

2. Description of the Related Art There have been known a large number of release treatment agents of this type, which are mainly composed of silicone-based polymers, fluorine-based polymers, long-chain alkyl-based polymers, and the like. It is used for applications that take advantage of each feature.

[0003] In recent years, with the progress of technology, the demands for release treatment agents have been diversified and advanced. Among these requirements, besides the basic properties such as light peeling force and little transfer to the adhesive surface and the inherent properties of the adhesive are not impaired, it must also be excellent in printability with various inks. In addition, a stable peeling force with little change over time can be obtained, and characteristics such as a smooth peeling independent of the peeling speed and a small peeling sound can be given.

[0004] In response to these requirements, for example, a silicone-based release agent containing resin fine particles having an affinity for an organic solvent with respect to a curable polyorganosiloxane (JP-A-5-156216). And a combination of a specific siloxane-modified acrylic polymer and an organohydrogenpolysiloxane (Japanese Patent Laid-Open No.
No. 329987) has been proposed.

[0005] As a long-chain alkyl-based release agent, a reaction product of an active hydrogen-containing polymer and a long-chain aliphatic isocyanate compound as a main component (Japanese Patent Laid-Open No. 5-29)
No. 5332) or an addition compound of a polyamine compound and a long-chain alkyl monoisocyanate compound containing a compound having a functional group capable of reacting with active hydrogen of an amino group (JP-A-6-73351). And so on.

[0006]

However, the silicone-based releasable treating agent proposed above provides a light and stable peeling force with little change over time, and also has an effect of improving the printing suitability with ink. In addition, the ink has selectivity, and in this respect, it lacks versatility. In addition, although the above-described long-chain alkyl-based release agent has excellent printability with ink, the release force is large and its change with time is also recognized, so that the release speed dependence at the time of release is large, and the release noise is high. However, there was a drawback that it would grow inevitably.

According to the present invention, there is provided an adhesive tape which is excellent in printability, can be printed beautifully with various inks, has a light and stable peeling force with little change over time, and has a small peeling sound. An object of the present invention is to provide a releasable treating agent for use.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies on the above objects and as a result, have found that a pseudo-crosslinked structure such as a polystyrene chain or a polyethylene chain and a carbon-carbon double bond in one molecule. Specific polymer compounds having an elastomeric structure, such as a chain or ethylene-propylene copolymer chain, have excellent printability and release characteristics with ink, can be printed beautifully with various inks, and have a light release force and change over time. The present inventors have found that a peeling agent having a small peeling sound at the time of peeling can be obtained, and completed the present invention.

That is, the present invention relates to a release treatment agent for pressure-sensitive adhesive tapes mainly comprising a polymer compound having a pseudo-crosslinked structure portion and an elastomer structure portion in one molecule (claim 1). In this release treatment agent, the ratio of the pseudo-crosslinked structure in the polymer compound is 20 to 90% by weight, and the ratio of the elastomeric structure in the polymer compound is 80 to 10% by weight. Wherein the pseudo-crosslinked structure part is a polyethylene chain or a polystyrene chain (Claim 3);
Preferred configurations are a carbon double bond chain or an ethylene-propylene copolymer chain (claim 4), and a configuration in which the weight average molecular weight of the polymer compound is 10,000 to 500,000 (claim 5). .

Further, the present invention provides a release treatment agent for pressure-sensitive adhesive tapes comprising 0.1 to 10 parts by weight of a lubricant per 100 parts by weight of a main agent comprising the above-mentioned polymer compound. 6). Further, the present invention provides, in such a variety of peeling treatment agents for pressure-sensitive adhesive tapes, a constitution in which the pressure-sensitive adhesive tapes use an acrylic pressure-sensitive adhesive (Claim 7). And

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer compound used in the present invention has a pseudo-crosslinked structure portion and an elastomer structure portion in one molecule, and the pseudo-crosslinked structure portion has a domain (domain) structure or a crystal. The elastomeric structure plays a role of imparting rubber-like properties to the polymer, while the structure plays a role of a crosslinking point of the polymer.

As such a pseudo-crosslinked structure portion, a polyethylene chain or a polystyrene chain is desirable. These chains increase the cohesive force of the release-treated film, contribute to the improvement of heat resistance, and reduce the interaction with the adhesive. Suppress to reduce the peeling force. On the other hand, as the above-mentioned elastomer structure portion, a carbon-carbon double bond chain or an ethylene-propylene copolymer chain, which has a small interaction with the pressure-sensitive adhesive and is convenient for light and smooth peeling, is used. Desirably, these are
By giving a good film-forming ability to the release treatment agent,
This enables the formation of a peeling-free film without any holes.

In the polymer compound used in the present invention,
The proportion occupied by the pseudo-crosslinked structure portion is 20 to 90% by weight,
It is preferably 40 to 80% by weight, and the proportion occupied by the elastomer structure portion is 80 to 10% by weight, preferably 6%.
It is preferably from 0 to 20% by weight. 2 pseudo-crosslinking structures
If the amount is less than 0% by weight and the amount of the elastomer structure portion exceeds 80% by weight, the cohesive force of the release treatment film is reduced, heat resistance is inferior, interaction with the adhesive becomes large, and the release force becomes heavy. And the peeling sound at the time of peeling increases. On the other hand, when the pseudo-crosslinked structure portion exceeds 90% by weight and the elastomer structure portion becomes less than 10% by weight, the melt viscosity as a releasable treating agent increases, resulting in poor film-forming properties and poor film-forming properties. The inconvenience tends to occur.

The high molecular compound having such two structural parts has a weight average molecular weight of 10,000 to 500,000, preferably 50,000 to 300,000. When the weight average molecular weight is smaller than 10,000, the heat resistance of the release treatment film is reduced,
Easy to form film. Further, the weight average molecular weight is 50
If it is less than 10,000, the solubility in a solvent becomes poor, and a problem is likely to occur in terms of handleability such as coating workability.

As such a high molecular compound, a trans-polyoctene rubber having a pseudo-crosslinking structure part comprising a polyethylene chain and an elastomer structure part comprising a carbon-carbon double bond chain (for example, a product sold by Impetx Chemicals Co., Ltd.) Vestenema-8012 "), polystyrene / ethylene-propylene copolymer block rubber having a pseudo-crosslinked structure part consisting of a polystyrene chain and an elastomer structure part consisting of an ethylene-propylene copolymer chain (for example," Septon 1050 "manufactured by Kuraray Co., Ltd.), etc. Is mentioned.

The release agent for adhesive tapes of the present invention comprises:
The polymer compound having the above-described structure is used as a main component, and is usually used as a low-concentration solution in which the above-mentioned polymer compound is dissolved in an appropriate organic solvent such as toluene. To this solution, an appropriate additive can be added in order to make the performance of the release treatment agent more excellent. The most typical of these additives is a lubricant. This lubricant exists on the surface of the release-treated film, controls the interaction with the adhesive, and is effective in obtaining an appropriate release force.

Examples of such a lubricant include hydrocarbon lubricants such as liquid paraffin, natural paraffin, synthetic paraffin, low molecular weight polyethylene, fatty acid lubricants such as higher fatty acids and oxy fatty acids, and fatty acids such as fatty acid amides and alkylene bis fatty acid amides. Ester lubricants such as amide lubricants, fatty acid lower alcohol esters, fatty acid polyhydric alcohol esters, and fatty acid polyglycol esters, and alcohol lubricants such as aliphatic alcohols, polyhydric alcohols, and polyglycols. No.

The amount of these lubricants is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the polymer compound. If the amount is less than 0.1 part by weight, the effect of the addition is poor.

The release agent for adhesive tapes of the present invention comprises:
This is applied to one or both sides of a base material such as paper, cloth, metal foil, plastic film, etc., and dried to form a release-treated film having a desired thickness, and used as a separator for adhesive tapes. . This separator uses various types of adhesive tapes such as double-sided adhesive tapes, double-sided adhesive labels, and even surface protection sheets.
It is used for the purpose of protecting the adhesive surface until it is put to practical use. Further, in addition to such a separator, the above-mentioned release treatment agent is applied to the back side of a single-sided adhesive tape or the like, and dried to facilitate winding and laminating of the tape. Also used in such as.

Here, the release treatment film formed on the back side of the separator base material or the adhesive tape has excellent printability on the film surface, that is, the release treatment surface, and prints beautifully with various inks. It is possible. In addition, this release treatment film shows a stable release force that is light and has little change over time on an adhesive surface such as an adhesive tape, and enables a smooth release independent of the release speed. Further, the peeling sound at the time of peeling can be reduced as compared with the case where a conventional peeling agent is used.

Such a peeling effect is particularly remarkably exhibited when the pressure-sensitive adhesive tape uses an acrylic pressure-sensitive adhesive. Therefore, the release treatment agent of the present invention is particularly effective for such acrylic pressure-sensitive adhesive tapes. The acrylic pressure-sensitive adhesive may be a normal pressure-sensitive adhesive obtained by adding a crosslinking agent such as a polyisocyanate compound to an acrylic copolymer, or may be a curable pressure-sensitive adhesive.

[0022]

Next, an embodiment of the present invention will be described in more detail. In the following, “parts” means “parts by weight”.

Example 1 As a high molecular compound, a transformer having a weight average molecular weight of 120,000 and having 76% by weight of a polyethylene chain (pseudo-crosslinked structure portion) and 24% by weight of a carbon-carbon double bond chain (estramer structural component). Octenema rubber ("Vestenema-8012", available from Impetx Chemicals Co., Ltd.) was used and dissolved in toluene to prepare a release treatment agent comprising a 10% by weight solution of the polymer compound.

One surface of a polyester film ("Lumilar" manufactured by Toray Industries, Inc.) is subjected to a corona treatment to reduce the surface tension to 52%.
After setting it to dyne / cm, this corona treated surface
Using a bar (No. 7), the above-mentioned release treatment agent was applied, and dried at 130 ° C. for 2 minutes with a hot air drier.
A separator having a release treatment film was produced.

Next, a copolymer of 100 parts of 2-ethylhexyl acrylate and 2 parts of acrylic acid was added to the same polyester film as described above, and a polyisocyanate was used as a crosslinking agent.
An acrylic pressure-sensitive adhesive solution to which 1 part of the compound (1) was added was applied so that the solid content after drying was 20 μm, and dried to prepare a pressure-sensitive adhesive tape. The peeled surface of the separator, that is, the surface having a peeled film, was bonded to the adhesive surface of the adhesive tape to obtain an adhesive tape with a separator.

Example 2 1% by weight of benzophenone peroxide as a polymerization initiator was added to a toluene solution of 10% by weight of trans octene rubber used in Example 1, and the mixture was reacted under a nitrogen stream to obtain a weight average molecular weight. Obtained 180,000 transoctene rubber. This toluene solution was used as a release treatment agent, and an adhesive tape with a separator was prepared in the same manner as in Example 1 using the same.

Example 3 To a 10% by weight toluene solution of trans-octene rubber used in Example 1, 3 parts of natural paraffin ("Parafin Wax 135" manufactured by Nippon Oil Co., Ltd.) was added as a lubricant, and peelability was improved. Example 1 was used as a treating agent.
In the same manner as in the above, an adhesive tape with a separator was produced.

Example 4 A toluene solution of transoctene rubber having a weight average molecular weight of 180,000 obtained in Example 2 was added to a toluene solution of low molecular weight polyethylene ("A" manufactured by Allied Chemical Company) as a lubricant.
C polyethylene 6A ") was added as a release treatment agent, and this was used to produce an adhesive tape with a separator in the same manner as in Example 1.

Example 5 As a high molecular compound, 50% by weight of a polystyrene chain (pseudo-crosslinked structure portion) and 50% of an ethylene-propylene copolymer chain were used.
Polystyrene / ethylene-propylene copolymer block rubber having a weight average molecular weight of 150,000 (Septon 105 manufactured by Kuraray Co., Ltd.)
0 ") was dissolved in toluene to prepare a release treatment agent comprising a 10% by weight solution of the polymer compound. Using this release treatment agent, an adhesive tape with a separator was prepared in the same manner as in Example 1.

Example 6 To a 10% by weight toluene solution of the polystyrene / ethylene-propylene copolymer block rubber used in Example 5 was added 3 parts of a fatty acid amide ("Diamid 200" manufactured by Nippon Hydrogen Corporation) as a lubricant. Then, an adhesive tape with a separator was prepared in the same manner as in Example 1 by using this as a release treatment agent.

Comparative Example 1 On the other hand, a 1% by weight toluene solution of "Pyroyl 1010" manufactured by YAS Co., Ltd. as a long-chain alkyl-based release agent was added to the polyester film used in Example 1 as a Myerbar.
(No. 10) and dried at 130 ° C. for 2 minutes with a hot air drier to obtain a separator having a release-treated film. Using this separator, an adhesive tape with a separator was manufactured in the same manner as in Example 1.

Comparative Example 2 The polyester film used in Example 1 was treated with a silicone-based release agent, "KS-7" manufactured by Shin-Etsu Chemical Co., Ltd.
23AB "in 1% by weight toluene solution
(No. 10) and dried at 130 ° C. for 2 minutes with a hot air drier to obtain a separator having a release-treated film. Using this separator, an adhesive tape with a separator was prepared in the same manner as in Example 1.

With respect to each of the pressure-sensitive adhesive tapes with separators in Examples 1 to 6 and Comparative Examples 1 and 2, a peeling force test and a peeling sound test after a lapse of time were performed by the following methods. Also,
A printability test for the release-treated surface of each separator, ie, the surface of the release-treated film, was conducted by the following method. These results were as shown in Table 1.

<Peeling Force Test> The adhesive tape with the separator was attached to the adhesive surface and left at room temperature for 30 minutes.
180 ° peeling of the separator at 00mm / min.
The peel force was examined.

<Exfoliation sound test after aging> The adhesive tape with the separator was attached to the adhesive surface with the separator, left at 50 ° C. for one day, and then subjected to a 300 mm tensile speed using a universal tensile tester. The separator was peeled at a rate of 180 degrees per minute and the peeling sound was observed.

<Printing Suitability Test> Printing was performed on the release-treated surface of the separator using a wax resin-based or resin-based ink by a thermal transfer method, and the printing suitability was examined.
When the printed characters were not disturbed visually and when the eraser was reciprocated 10 times by applying a load of 2 kg, the character was evaluated as "good" when there was no stain or falling off of the character, and "bad" when there was a certain character.

[0037]

As is clear from Table 1 above, the releasable treating agent of the present invention has excellent printability, and has a small peeling force on an adhesive tape using an acrylic adhesive. Can be peeled off smoothly, so the peeling sound is reduced.

[0039]

As described above, the present invention uses a high molecular compound having a pseudo-crosslinked structure portion and an estramer structure portion in one molecule as a main component, thereby being excellent in ink aptitude for printing and peeling properties. Can be printed beautifully even with
In addition, it is possible to provide a releasable treating agent that has a small peeling force, has little change with time, and has a small peeling sound when peeling.

Claims (7)

[Claims] 1. A releasable treating agent for pressure-sensitive adhesive tapes comprising, as a main component, a polymer compound having a pseudo-crosslinked structure portion and an elastomer structure portion in one molecule. 2. The adhesive tape according to claim 1, wherein the proportion of the pseudo-crosslinked structure portion in the polymer compound is 20 to 90% by weight, and the proportion of the elastomeric structure portion is 80 to 10% by weight. Release treatment agent. 3. The release agent for pressure-sensitive adhesive tapes according to claim 1, wherein the pseudo-crosslinked structure portion is a polyethylene chain or a polystyrene chain. 4. The release agent for pressure-sensitive adhesive tapes according to claim 1, wherein the elastomer structure part is a carbon-carbon double bond chain or an ethylene-propylene copolymer chain. 5. The polymer compound has a weight average molecular weight of 10,000 or more.
The pressure-sensitive adhesive tape according to any one of claims 1 to 4, which has a viscosity of 500,000.
Peeling treatment agent for plastics. 6. The release agent for pressure-sensitive adhesive tapes according to claim 1, wherein a lubricant is contained in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the main agent comprising the polymer compound. . 7. The release agent for pressure-sensitive adhesive tapes according to claim 1, wherein the pressure-sensitive adhesive tapes comprise an acrylic pressure-sensitive adhesive.