JPH0643575B2 - Adhesive sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pressure-sensitive adhesive sheet, and more specifically, to a pressure-sensitive adhesive comprising a diene-based copolymer on a base material sheet comprising a polyurethane-polyvinyl chloride composite containing no plasticizer. Relates to a pressure-sensitive adhesive sheet that is directly and firmly adhered and can be suitably used as, for example, a patch.

Conventional technology Adhesive sheets are used in various applications, for example,
BACKGROUND OF THE INVENTION Patches prepared by laminating an adhesive containing a drug such as a skin stimulant or an anti-inflammatory analgesic on a base sheet are used for medical purposes. In such a patch, for example, as described in JP-A-54-138124, not only does the patch have good adhesiveness and elasticity when it is applied to the skin, but also when it is peeled off. It is known that a diene-based copolymer, particularly a diene-based block copolymer, is preferable as the adhesive because it can be easily peeled off without irritating the skin.

On the other hand, in the patch as described above, as the base sheet, a vinyl chloride resin which is soft and conforms to the skin is preferable, but on the other hand, the vinyl chloride resin sheet is a diene-based adhesive as an adhesive. Poor affinity with block copolymer, especially in patch, since diene block copolymer as an adhesive contains higher fatty acid and fluid paraffin as a plasticizer together with a drug, vinyl chloride type Poor affinity with resin base sheet. As a result, when a pressure-sensitive adhesive composed of a diene-based block copolymer is simply applied directly onto a vinyl chloride-based resin base sheet to form a patch, there is a problem in that the adhesiveness of the pressure-sensitive adhesive to the base sheet is poor.

Therefore, it is possible to increase the affinity for the diene block copolymer by subjecting the vinyl chloride resin sheet to an appropriate primer treatment, but with this method, as the number of steps increases, However, the manufacturing cost must be high.

In order to solve such a problem, for example, JP-A-62-2
No. 27983 discloses that a resin composition obtained by mixing styrene-ethylene-butylene-styrene block copolymer with polyvinyl chloride together with ethylene-vinyl acetate copolymer and thermoplastic polyurethane is processed into a base sheet. A method for producing a pressure-sensitive adhesive sheet by laminating and bonding a pressure-sensitive adhesive comprising a styrene-diene-styrene block copolymer on this base sheet has been proposed.

However, according to this method, the physical properties of the base sheet are deteriorated with time, such as the agent in the pressure-sensitive adhesive migrating into the base sheet, and the strength of the base sheet is impaired. -Ethylene-butylene-styrene block copolymer is not necessarily compatible, at the stage of processing the resin composition into a substrate sheet, the copolymer is difficult to gel, the resulting substrate sheet has a hole To do. Further, the base sheet containing the styrene-ethylene-butylene-styrene block copolymer has rubber elasticity due to this copolymer, and the smoothness and suppleness inherent in the soft vinyl chloride resin are lost. Further, it is desired that the base sheet has transparency, but the base sheet containing the styrene-ethylene-butylene-styrene block copolymer is opaque.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention has been made to solve the above-mentioned problems, and is a group comprising a polyurethane-polyvinyl chloride composite containing no tackifier resin and containing a plasticizer. A pressure-sensitive adhesive comprising a diene block copolymer is directly and firmly adhered and laminated on a material sheet, and is excellent in feeling and flexibility, and, for example, provides a pressure-sensitive adhesive sheet which can be suitably used as a patch. The purpose is to

Means for Solving the Problems In the pressure-sensitive adhesive sheet according to the present invention, with respect to 100 parts by weight of the polyurethane-polyvinyl chloride composite, tackifying resins 5 to 3 are used.
It is characterized in that a pressure-sensitive adhesive made of a styrene-diene-styrene block copolymer is laminated and adhered on a base material sheet made of a resin composition containing 0 part by weight.

In the present invention, the polyurethane-polyvinyl chloride composite is a polyvinyl chloride graft polyurethane copolymer obtained by dissolving thermoplastic polyurethane in a vinyl chloride monomer and carrying out suspension polymerization (for example, JP-A-58-40312).
JP-A-58-42611, JP-A-58-
No. 37019, etc. ), A solid polyvinyl chloride is impregnated with a polyol, and then polyisocyanate is added thereto to form a polyurethane in the solid polyvinyl chloride (for example, Japanese Examined Patent Publication No.
9-39464 and the like. ), A mixture of polyvinyl chloride, polyol and polyisocyanate are heated and melted to form polyurethane (for example, JP-A-62-1715 and JP-A-63-163).
It is described in Japanese Patent No. 251413. ) Etc.

For example, JP-A-63-251413 discloses a method of obtaining a polyurethane-polyvinyl chloride composite by adding a polyester polyol to a mixture containing polyvinyl chloride powder and hexamethylene diisocyanate and reacting the mixture under heating and melting. Have been described. In the present invention, in particular,
Such a polyurethane-polyvinyl chloride composite is preferably used. Such a polyurethane-polyvinyl chloride composite is already commercially available, and for example, in the present invention, a polyurethane-polyvinyl chloride composite commercially available as "Dominus" from Tosoh Corporation is preferably used. You can

The substrate sheet used in the present invention is obtained by filming a resin composition containing 5 to 30 parts by weight of a tackifying resin with respect to 100 parts by weight of a polyurethane-polyvinyl chloride composite by, for example, a calendar method. You can

In the present invention, as the tackifying resin, in particular,
At least one selected from the group consisting of alicyclic saturated hydrocarbon, hydrogenated rosin ester and ketone resin and having a softening point (by the ring and ball method) in the range of 40 to 150 ° C. is preferably used. To be When the tackifying resin has a softening point lower than 40 ° C., in the obtained pressure-sensitive adhesive sheet, the tackifying resin migrates to the pressure-sensitive adhesive layer described later with time and causes stickiness in the pressure-sensitive adhesive layer. When used as a patch, the application feeling is significantly deteriorated. On the other hand, when the adhesion-imparting resin has a softening point higher than 150 ° C., the compatibility with the polyurethane-polyvinyl chloride composite is poor and it remains ungelled during film processing to obtain a uniform film. Will be difficult.

When a tackifying resin other than those mentioned above is used, the resulting polyurethane-polyvinyl chloride composite has poor heat resistance such as thermal decomposition or discoloration when processed into a film, and the resulting substrate. A strong adhesive force cannot be achieved between the sheet and the pressure-sensitive adhesive layer described below.

However, according to the present invention, in particular, at least one selected from the group consisting of alicyclic saturated hydrocarbons, hydrogenated rosin ester and ketone resins, and 40-
When a tackifying resin having a softening point in the range of 150 ° C. is used, it is possible to obtain a uniform film having strong adhesion to the pressure-sensitive adhesive layer described later, and moreover, in the resulting pressure-sensitive adhesive sheet, the tackifying resin is aged over time. It is possible to obtain a medicated patch which is excellent in application feeling without shifting to the pressure-sensitive adhesive layer.

However, when such a tackifying resin is used too much, in the resulting pressure-sensitive adhesive sheet, it is unavoidable that the tackifying resin migrates to the pressure-sensitive adhesive layer over time, while when too little, the pressure-sensitive adhesive is In the present invention, the tackifying resin is a polyurethane-polyvinyl chloride composite 10 since strong adhesion with the layers cannot be achieved.
About 0 parts by weight, it is contained in the range of 5 to 30 parts by weight.

The polyurethane-polyvinyl chloride composite film used in the present invention is a plastic-free soft film containing no plasticizer because the polyurethane component functions as a plasticizer. When a polyurethane-polyvinyl chloride composite contains a plasticizer together with a tackifying resin, it causes stickiness during film processing, making film processing difficult, and blooming or bleeding of the plasticizer or the tackifying resin on the film surface. And so on. Furthermore, even in the obtained pressure-sensitive adhesive sheet, the pressure-sensitive adhesive layer becomes sticky over time, which is not preferable.

In the present invention, the polyurethane-polyvinyl chloride graft composite film preferably has a thickness in the range of 50 to 150 μm so as not to cause a feeling of strangeness when applied to the skin. Particularly, the range of 70 to 100 μm is suitable. When it is too thin, the strength is not practically sufficient, while when it is too thick, it is easily peeled off after sticking to the skin, which is not preferable.

Furthermore, in the present invention, the polyurethane-polyvinyl chloride composite film preferably contains a suitable amount of a so-called non-toxic stabilizer. As a suitable example of such a stabilizer,
For example, calcium-zinc-based stabilizers, which are already well known as stabilizers for vinyl chloride resins, can be mentioned, but are not particularly limited to the above as long as they are non-toxic.

Further, the polyurethane-polyvinyl chloride graft copolymer may contain a filler. The filler is, for example,
When the base material sheet is a roll, its developability is enhanced.
That is, it is effective in improving the blocking resistance. The filler is usually added in an amount of 30 parts by weight or less with respect to 100 parts by weight of the polyurethane-polyvinyl chloride graft copolymer.

Further, the polyurethane-polyvinyl chloride graft copolymer may contain polyvinyl chloride. in this case,
Polyvinyl chloride has an average degree of polymerization of 400 to 2000,
In particular, it is preferably in the range of 700 to 1400.
However, when blended in an excessive amount, the compatibility with the skin is deteriorated. Therefore, the blending amount is preferably 30 parts by weight or less per 100 parts by weight of the polyurethane-polyvinyl chloride graft copolymer.

In the pressure-sensitive adhesive sheet according to the present invention, a layer of styrene-diene-styrene block copolymer as a pressure-sensitive adhesive is directly laminated and adhered on the base sheet. According to the invention,
Since the base material sheet comprising the above resin composition contains the above-mentioned tackifying resin, it has an excellent affinity for styrene-ethylene-butylene-styrene block copolymer,
When a pressure sensitive adhesive composed of a styrene-diene-styrene copolymer is applied thereon, high adhesiveness can be obtained during that time.

In the present invention, styrene-diene-constituting the pressure-sensitive adhesive
Specific examples of the styrene block copolymer 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 a pressure-sensitive adhesive, or a composition containing a plasticizer, a tackifying resin, a filler, an antioxidant and the like together with these block copolymers. It may be used as a product. Further, it may contain a necessary drug as in the case of the above-mentioned attached drug.

Such a styrene-diene-styrene block copolymer is already known as described in detail in, for example, JP-A-54-138124 mentioned above, and A is a glassy or hard non-polymer made of styrene. When the block is an elastic thermoplastic polymer and B is the block of an elastic polymer of a conjugated diene such as butadiene or isoprene, the block copolymer having the structure ABA, in which all the blocks A are It accounts for 10 to 50% by weight of the polymer weight. Such styrene-butadiene-styrene block copolymers are known as Califlex TR-1101, TR-.
1102 and the like, and styrene-isoprene and styrene block copolymers are Califlex TR-1107.
(All manufactured by Ciel Chemical Co., Ltd.),
Can be obtained.

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

EFFECTS OF THE INVENTION As described above, according to the pressure-sensitive adhesive sheet of the present invention, the polyurethane-polyvinyl chloride composite does not contain a plasticizer, but it contains a tackifying resin and is processed into a film, Since it is used as a base sheet, such a film has not only excellent feeling and flexibility, but also excellent affinity with a styrene-diene-styrene block copolymer, so that it can be used as an adhesive on the base sheet. The styrene-diene-styrene block copolymer is directly and firmly adhered, and can be suitably used, for example, as a patch.

Further, according to the pressure-sensitive adhesive sheet of the present invention, there is no component that migrates from the base material sheet to the pressure-sensitive adhesive, and on the other hand, since it does not contain a styrene-ethylene-butylene-styrene block copolymer, the drug in the pressure-sensitive adhesive is a base material. It does not migrate into the sheet, thus the adhesiveness of the adhesive sheet is maintained over a long period of time, and the physical properties of the substrate sheet do not deteriorate over time, such as the strength of the substrate sheet, and durability is improved. It is excellent and has little skin irritation when used as a patch.

Further, according to the present invention, since the resin composition does not contain a styrene-ethylene-butylene-styrene block copolymer, even when the resin composition is processed into a base material sheet, no perforation occurs and it is obtained. The base sheet is transparent.

EXAMPLES The present invention will be described below with reference to examples. In the following, parts mean parts by weight.

Example As shown in Table 1, a polyurethane-polyvinyl chloride composite (Dominus K-800C manufactured by Tosoh Corp.) was kneaded together with a tackifying resin, a stabilizer, and optionally polyvinyl chloride, and subjected to a calendering method. To obtain a film having a thickness of 80 μm.

Styrene-Isprene-as an adhesive on this film
Styrene block copolymer (Califlex TR-1107)
Was melt-coated at a rate of 70 g / m ² to prepare an adhesive sheet.

With respect to these pressure-sensitive adhesive sheets, the adhesiveness between the film and the pressure-sensitive adhesive layer, its change over time, thermochromic discoloration and the like were examined. The results are shown in Table 1.

In the above evaluation, the adhesion between the film and the pressure-sensitive adhesive layer immediately after production and after being left at 40 ° C. for 1 week was determined by attaching a pressure-sensitive adhesive sheet having a width of 19 mm to a Bakelite plate and performing a 180 ° peel test at a pulling speed of 200 mm / min. Line When the adhesive residue was applied to the Bakelite plate in an amount of more than 5%, the result was x, in the range of 1 to 5% was Δ, and when it was less than 1%, it was o.

The stickiness of the pressure-sensitive adhesive layer after standing at 40 ° C. for 1 hour was judged by touch with a finger. ○: no stickiness, △: slightly sticky, but practically no problem, ×: sticky, It means that it cannot be put to practical use.

As for the thermochromic property, a polyurethane-polyvinyl chloride composite (Dominus K-800C manufactured by Tosoh Corporation) was used together with a tackifier resin, a stabilizer and, if necessary, polyvinyl chloride.
The color difference meter (Nihon Denki Co., Ltd.) was kneaded at 0 ° C. for 20 minutes, formed into a film with a thickness of 1 mm by a roll, kneaded at 180 ° C. for 5 minutes and formed into a film with a thickness of 1 mm by reference. The color difference (ΔE) is measured by SZ-Σ80 manufactured by Color Co., and when ΔE exceeds 10, it is ×, between 3 and 10 is Δ,
When it was less than 3, it was evaluated as ◯.

Further, for comparison, a polyvinyl chloride film containing a plasticizer and a tackifying resin is used to make a film, and a polyurethane-polyvinyl chloride composite film containing neither a plasticizer nor a tackifying resin is used to make a film. Then, using each of these as a substrate, a pressure-sensitive adhesive sheet was prepared in the same manner as in Example (Comparative Examples 1 and 2). In these pressure-sensitive adhesive sheets, the tackiness of the pressure-sensitive adhesive layer is remarkable over time, or they do not adhere to the pressure-sensitive adhesive layer.

When the compounding amount of the tackifying resin is too small or too large, the film does not adhere to the pressure sensitive adhesive layer, or thermal discoloration is remarkable.

On the other hand, each of the pressure-sensitive adhesive sheets according to the present invention can achieve strong adhesion between the film and the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer does not become sticky with time.

Claims (2)

[Claims] 1. A polyurethane-polyvinyl chloride composite 10
About 0 parts by weight, a pressure-sensitive adhesive made of a styrene-diene-styrene block copolymer is laminated and adhered on a base material sheet made of a resin composition containing 5 to 30 parts by weight of a tackifying resin. Adhesive sheet. 2. The tackifying resin is at least one selected from the group consisting of alicyclic saturated hydrocarbons, hydrogenated rosin ester and ketone resins, and has a softening point in the range of 40 to 150 ° C. The pressure-sensitive adhesive sheet according to claim 1, wherein: