JPH0457873A - adhesive sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to an adhesive sheet.
The present invention relates to a pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive made of a diene copolymer is directly and strongly adhered to a base sheet made of a polyvinyl chloride composite, and which can be suitably used as a medicinal patch, for example.

Conventional Ibarado adhesive sheets have been used for various purposes, such as:
BACKGROUND OF THE INVENTION Patch medicines made by laminating an adhesive containing drugs such as skin irritants and anti-inflammatory analgesics on a base sheet are used for medical purposes. For example, as described in JP-A No. 54-138124, such patch medicines not only have good adhesiveness and elasticity when applied to the skin, but also have good adhesiveness and elasticity when removed from the skin. It is known that diene-based copolymers, particularly diene-based block copolymers, are suitable as adhesives because they do not cause irritation and can be easily peeled off.

On the other hand, for the above-mentioned patches, vinyl chloride resin is suitable as the base sheet because it is flexible and blends well with the skin. It has poor affinity with block copolymers, and in particular, in patch drugs, diene block copolymers as adhesives contain higher fatty acids and liquid paraffin as plasticizers together with drugs, so vinyl chloride-based Compatibility with the resin base sheet is even poorer.

As a result, when a pressure-sensitive adhesive made of a diene block copolymer is simply applied directly onto a vinyl chloride-based resin base sheet to form a patch, there is a problem that the adhesive properties of the pressure-sensitive adhesive to the base sheet are poor.

Therefore, it is possible to increase the affinity for the diene block copolymer by subjecting the vinyl chloride resin sheet to an appropriate brimer treatment, but this method requires an increase in the number of steps. , manufacturing costs inevitably increase.

In order to solve this problem, for example, Japanese Patent Laid-Open No. 62-2
No. 27983 discloses that a resin composition obtained by mixing polyvinyl chloride with an ethylene-vinyl acetate copolymer, a thermoplastic polyurethane, and a styrene-ethylene-butylene-styrene block copolymer is molded into a base sheet. A method has been proposed in which a pressure-sensitive adhesive sheet made of a styrene-diene-styrene block copolymer is laminated and bonded onto this base sheet.

However, according to this method, the chemical in the adhesive migrates into the base sheet, impairing the strength of the base sheet, and the physical properties of the base sheet deteriorate over time. is not necessarily compatible with the styrene-ethylene-butylene-styrene block copolymer, and at the stage of processing the resin composition into a base sheet, the copolymer is difficult to gel and the resulting base sheet has holes. occurs. Further, a base sheet containing a styrene-ethylene-butylene-styrene block copolymer has rubber elasticity due to this copolymer, and loses the smoothness and suppleness inherent to the soft vinyl chloride resin.

Furthermore, although it is desired that the base sheet has transparency, a base sheet containing a styrene-ethylene-butylene-styrene block copolymer is opaque.

The present invention has been made to solve the above-mentioned problems, and uses ethylene-vinyl acetate as a tackifying resin.
An adhesive made of a diene block copolymer is directly and firmly adhered and laminated onto a base sheet made of a polyurethane-polyvinyl chloride composite containing a carbon monoxide copolymer, resulting in improved texture and flexibility. It is an object of the present invention to provide a pressure-sensitive adhesive sheet that can be suitably used, for example, as a patch.

The pressure-sensitive adhesive sheet of the present invention for reading fortune-telling contains 100 parts by weight of a polyurethane-polyvinyl chloride composite and 1 to 60 parts of an ethylene-vinyl acetate-M carbon copolymer as a tackifying resin.
A pressure-sensitive adhesive made of a styrene-diene-styrene block copolymer is laminated and bonded onto a base sheet made of a resin composition containing parts by weight.

In the present invention, the polyurethane-polyvinyl chloride composite is a polyvinyl chloride graft polyurethane copolymer obtained by dissolving thermoplastic polyurethane in vinyl chloride monomer and subjecting it to suspension polymerization (for example, JP-A-58-40312
Publication No. 42611/1983, Japanese Patent Application Laid-Open No. 1987-42611
It is described in Publication No. 37019 and the like. ), solid polyvinyl chloride is impregnated with a polyol, and then polyisocyanate is added thereto to produce polyurethane in the solid polyvinyl chloride (for example, copolymers made by
It is described in Publication No. 9-39464 and the like. ), a composite obtained by heating and melting a mixture of polyvinyl chloride, polyol and polyisocyanate to produce polyurethane (for example, JP-A-62-1715, JP-A-632)
It is described in Publication No. 51413 and the like. ) etc.

For example, JP-A No. 63-251413 discloses a method for obtaining a polyurethane-polyvinyl chloride composite by adding a polyester polyol to a mixture containing polyvinyl chloride powder and hexamethylene diisocyanate and causing the mixture to react while being heated and melted. is listed. In the present invention, in particular,
Such polyurethane-polyvinyl chloride composites are preferably used.

Such polyurethane-polyvinyl chloride composites are already commercially available. For example, in the present invention, a polyurethane-polyvinyl chloride composite commercially available as "Dominus J" from Tosoh can be suitably used. .

The base sheet used in the present invention contains 100 parts by weight of a polyurethane-polyvinyl chloride composite, and 1 to 10 parts of an ethylene-vinyl acetate-carbon oxide copolymer as a tackifying resin.
It can be obtained by forming a resin composition containing 60 parts by weight into a sheet, for example, by a calendering method.

The ethylene-vinyl acetate-carbon monoxide copolymer used as the tackifying resin in the present invention is already known, and for example, one commercially available from Mitsui-DuPont Polychemicals as "Elvaloy" is preferably used. be able to.

When the amount of the ethylene-vinyl acetate-carbon monoxide copolymer blended is less than 1 part by weight with respect to 100 parts by weight of the polyurethane-polyvinyl chloride composite, the adhesion between the base sheet and the adhesive is improved. On the other hand, when the amount exceeds 60 parts by weight, the ethylene-vinyl acetate-carbon monoxide copolymer has a low melt viscosity and gels more quickly than the polyurethane-polyvinyl chloride composite, and the raw resin is used in the production of the base sheet. The composition is prone to non-gelling. In particular, in the present invention, the ethylene-vinyl acetate-carbon monoxide combination is preferably used in an amount of 5 to 50 parts by weight per 100 parts by weight of the polyurethane-polyvinyl chloride composite.

In this way, according to the present invention, a predetermined amount of ethylene-vinyl acetate-
By using a carbon monoxide copolymer, it is possible to obtain a uniform base sheet that has strong adhesion to the adhesive layer, which will be described later. For example, it is possible to obtain a patch that does not migrate and feels smooth when applied.

Polyurethane used as base sheet in the present invention
Since the polyurethane component functions as a plasticizer, the polyvinyl chloride composite sheet can be a non-plasticized soft sheet that does not contain a plasticizer, but if necessary, the base sheet may contain a plasticizer. . However, when a polyurethane-polyvinyl chloride composite contains a large amount of plasticizer together with a tackifying resin, it becomes sticky during sheet manufacturing, making sheet manufacturing difficult. Bloom, bleed, etc. occur, and the adhesive layer of the resulting adhesive sheet also becomes sticky over time. Therefore, the plasticizer is preferably
It is used in an amount of 20 parts by weight or less per 100 parts by weight of the polyurethane-polyvinyl chloride composite. As the plasticizer, a high molecular weight polyester plasticizer is suitable.

In the present invention, the polyurethane-polyvinyl chloride graft composite sheet preferably has a thickness in the range of 50 to 150 μm so as not to cause discomfort when applied to the skin. If it is too thin, it will not have sufficient strength for practical purposes, and if it is too thick, it will easily peel off after being applied to the skin, which is not preferable.

Furthermore, in the present invention, the polyurethane-polyvinyl chloride composite sheet preferably contains an appropriate amount of a so-called non-toxic stabilizer. Suitable examples of such stabilizers include, for example, calcium-zinc stabilizers, which are already well known as stabilizers for vinyl chloride resins; however, as long as they are non-toxic, they are not particularly limited to the above. It is not something that will be done.

Furthermore, the polyurethane-polyvinyl chloride graft copolymer may contain fillers. Fillers include, for example,
When the base sheet is made into a roll, its expandability is improved.

That is, it is effective in improving blocking resistance. The filler is usually blended in an amount of 30 parts by weight or less per 100 parts by weight of the polyurethane-polyvinyl chloride graft copolymer.

Moreover, in the present invention, polyvinyl chloride may be used together with the polyurethane-polyvinyl chloride graft copolymer. Polyvinyl chloride has an average degree of polymerization of 400 to
2000, particularly preferably in the range of 700 to 1400. However, if too much is added, the adhesion to the skin will be impaired, so the appropriate amount is 30 parts by weight or less per 100 parts by weight of the polyurethane-polyvinyl chloride graft copolymer.

In the pressure-sensitive adhesive sheet of the present invention, a layer of a styrene-diene-styrene block copolymer as a pressure-sensitive adhesive is directly laminated and adhered onto the base sheet. According to the invention,
Since the base sheet made of the resin composition contains the tackifying resin described above and has excellent affinity for the styrene-ethylene-butylene-styrene block copolymer,
When a pressure-sensitive adhesive made of a styrene-diene-styrene copolymer is applied thereon, high adhesiveness can be obtained between the adhesives.

In the present invention, specific examples of the styrene diene-styrene block copolymer constituting the adhesive include a styrene-butadiene-styrene block copolymer and a styrene-isoprene-styrene block copolymer. These styrene-diene-styrene block copolymers may be used alone or as a mixture as an adhesive, or together with these block copolymers, plasticizers, tackifying resins other than those listed above, fillers, anti-aging agents, etc. may be used. It may be used as a composition containing. Furthermore, as in the case of the attached drug described above, it may contain necessary drugs.

Such styrene-diene-styrene block copolymers are already known, for example, as described in detail in the above-mentioned Japanese Patent Application Laid-open No. 54-138124. a block of an elastic thermoplastic polymer, and B is a block of an elastic polymer of a conjugated diene such as butadiene or isoprene;
A block copolymer having an A-BA structure, in which block A accounts for 10 to 50% by weight of the total polymer weight.

Such styrene-butadiene-styrene block copolymers are called Cariflex TR-110f, TR-110
In addition, a styrene-isoprene-styrene block copolymer is commercially available as Cariflex TR-1107 (all manufactured by Shell Chemical Co., Ltd.).

The adhesive sheet according to the present invention is produced by molding the resin composition into a base sheet by an appropriate method such as calendering or extrusion, and forming a styrene-diene-styrene block containing drugs and other additives as necessary. It can be obtained by melt coating a copolymer.

As described above, according to the adhesive sheet of the present invention, the base sheet is made of a polyurethane-polyvinyl chloride composite containing an ethylene-vinyl acetate-carbon monoxide copolymer as a tackifying resin. Therefore, such a base sheet not only has excellent texture and flexibility, but also has excellent adhesion to the styrene-diene-styrene block copolymer, so styrene-diene as an adhesive is used on the base sheet. - The styrene block copolymer is directly and strongly adhered, and can be suitably used as a patch, for example.

Furthermore, according to the pressure-sensitive adhesive sheet of the present invention, the ethylene-vinyl acetate-carbon monoxide copolymer used as the tackifying resin has excellent transparency and the processing temperature is low, so that thermal discoloration does not occur during the production of the base sheet. A substantially transparent base sheet can be obtained.

Further, as a preferred embodiment of the present invention, when the base sheet does not contain a plasticizer, there is no component that transfers from the base sheet to the adhesive;
Since it does not contain an ethylene-butylene-styrene block copolymer, the drug in the adhesive does not migrate into the base sheet, thus maintaining the adhesive properties of the adhesive sheet over a long period of time and increasing the strength of the base sheet. There is no deterioration in the physical properties of the base sheet over time, such as deterioration in the physical properties of the base sheet over time, the durability decreases, and there is little irritation to the skin when used as a patch.

Furthermore, according to the present invention, since the resin composition does not contain a styrene-ethylene-butylene-styrene block copolymer, no holes occur even in the step of processing this into a base sheet, and the resulting The base sheet is transparent.

EXAMPLES The present invention will be explained below with reference to Examples. In addition, in the following, parts mean parts by weight.

Examples As shown in Table 1, a polyurethane-polyvinyl chloride composite (Dominus -8000 manufactured by Tosoh Corporation) was kneaded with a tackifying resin, a stabilizer, and if necessary polyvinyl chloride and a plasticizer, and then calendered. A base sheet having a thickness of 130 μm was obtained.

A styrene-isoprene-styrene block copolymer (Califlex T) was applied as an adhesive on one side of this base sheet.
R-1107) was melt-coated to a thickness of 100 μm to prepare a pressure-sensitive adhesive sheet.

Regarding these pressure-sensitive adhesive sheets, the adhesiveness between the base sheet and the pressure-sensitive adhesive layer and the roll processability were examined as follows.

The results are shown in Table 1.

The pressure-sensitive adhesive sheet was cut into pieces with a convergence of 25 m and a length of 5 cm, which was wrapped and sealed with aluminum foil and left at 40°C for 2 weeks. After that, the adhesive sheet was taken out, attached to a Bakelite plate, left for 1 hour, and then stretched at room temperature at a tensile speed of 200 m/min for 18
A 0° peel test was conducted. The evaluation was based on the following. ○ indicates that the adhesive does not peel off from the base sheet, △ indicates that the adhesive partially peels off from the base sheet, but there is no particular problem in practical use, ×
indicates that almost all of the adhesive is peeled off from the base sheet.

200g of compound was kneaded using two 12-inch rolls heated to about 175°C and the distance between the rolls was set to 0.20. shape) and plate-out were comprehensively evaluated. The evaluation was based on the following. ○: Good, △: Smoothness is slightly decreased,
In practical use, there is no particular problem; × indicates poor lubricity, does not peel easily from the metal roll, and cannot be processed.

Patent applicant Band-Kagaku Co., Ltd. Agent Patent Attorney Itsu Makino

Claims (1)

[Claims] (1) For 100 parts by weight of a polyurethane-polyvinyl chloride composite, styrene- A pressure-sensitive adhesive sheet characterized in that a pressure-sensitive adhesive made of a diene-styrene block copolymer is laminated and bonded.