JPH09249855A - Tacky agent and tape or sheet for medical application using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare an aqueous emulsion type (meth)acrylic tacky agent excellent in adhesion to the skin and a tacky tape or sheet for medical applications using the tacky agent. SOLUTION: This aqueous emulsion type acrylic tacky agent excellent in adhesion comprises a mixture of an emulsion polymer prepared by using an alkyl (meth)acrylate having a 4-18C alkyl group as a main raw material monomer with a solution polymer obtained by using the alkyl (meth)acrylate having a 4-18C alkyl group as a main raw material monomer. Acrylic or methacrylic acid as a raw material monomer is contained in at least the emulsion polymer and the solid weight ratio of the solution polymer is 5-50pts. solution polymer based on 100pts. emulsion polymer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aqueous emulsion type acrylic pressure-sensitive adhesive having excellent initial adhesion to the skin and a medical pressure-sensitive adhesive tape or sheet using the same.

[0002]

[Prior Art] Adhesive bandages and surgical tapes used to fix gauze, bandages, catheters, infusion tubes and other human surfaces at home and in medical settings, first-aid bandages, salicylic acid adhesive bandages, delicate rubber patches, happs, steroid tapes, whole body The adhesives that have been used for therapeutic tapes and sheets such as medicinal transdermal preparations are generally rubber-based and acrylic-based.

The rubber-based pressure-sensitive adhesive is rich in rubber elasticity because the main constituent unit of the polymer chain is a conjugated diene compound.
It has good tack, adhesive strength, and holding power, but lacks storability and stability such as aging resistance and heat resistance, and is apt to cause discoloration or so-called adhesive residue especially under high temperature and high humidity conditions.

On the other hand, the acrylic pressure-sensitive adhesive is mainly composed of a copolymerized polymer having (meth) acrylic acid alkyl ester as a main raw material monomer, so that it is rubber-resistant in terms of aging resistance, heat stability and weather resistance. It is far superior to the system. Also, as is well known, acrylic adhesives
Depending on the form, there are solution type (solution polymerization type) and aqueous emulsion type (emulsion polymerization type), but in recent years, due to social needs such as pollution control, resource conservation, safety and health, the shift to non-solvent type has been steadily made. It's progressing. In particular, when the base material to which the pressure sensitive adhesive is applied is paper or a textile product, the water-based emulsion pressure sensitive adhesive is preferably used because the water-containing substance can be dried quickly.

[0005]

However, since the aqueous emulsion type acrylic pressure-sensitive adhesive contains a large amount of water and an emulsifier, the initial adhesiveness to the skin surface is lower than that of the solution type as it is. It's hard to avoid.

An object of the present invention is to improve the adhesiveness of an aqueous emulsion type acrylic pressure-sensitive adhesive immediately after being applied to the skin and to have excellent preservability, and a medical adhesive which is a coated product thereof. To provide tapes or sheets.

The inventors of the present invention have conducted extensive research, and based on a novel technical idea of modifying an aqueous emulsion type acrylic pressure-sensitive adhesive with a solution polymerization type acrylic pressure-sensitive adhesive, as a result of earnest research, The present invention has been completed by creating an aqueous emulsion type acrylic pressure-sensitive adhesive of the invention.

[0008]

DISCLOSURE OF THE INVENTION According to the present invention, an emulsion polymer obtained by using a (meth) acrylic acid alkyl ester having an alkyl group having 4 to 18 carbon atoms as a main raw material monomer and an alkyl group having carbon number of 4 to 18 (meth) acrylic acid alkyl ester as a main raw material monomer, and a mixture with a solution polymerized product, at least the emulsion polymerized product containing (meth) acrylic acid as a raw material monomer, and The solid emulsion weight ratio is 5 to 50 parts of the solution polymerized product with respect to 100 parts of the emulsion polymer, which is an aqueous emulsion type acrylic pressure-sensitive adhesive excellent in initial adhesion.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The emulsion polymer used in the production of the pressure-sensitive adhesive of the present invention comprises one or more kinds of (meth) acrylic acid alkyl ester as a main raw material monomer and at least (meth) acrylic acid as a comonomer raw material. (Meth) acrylic polymer emulsion having a weight average molecular weight of 200,000 to 1,000,000. This (meta)
The (meth) acrylic acid alkyl ester as a main raw material monomer for forming an acrylic polymer is an alkyl ester of acrylic acid or methacrylic acid having an alkyl group having 4 to 18 (preferably 6 to 12) carbon atoms,
Specific examples include butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and isooctyl (meth) acrylate. The concentration of the (meth) acrylic polymer in this emulsion is usually 50 to 60% by weight.
It is.

The emulsion polymer can be produced, for example, by the method described in Examples below.

On the other hand, the solution polymer used in the production of the pressure-sensitive adhesive of the present invention contains one or more kinds of (meth) acrylic acid alkyl ester as a main raw material monomer and acrylic acid as a comonomer raw material in the presence of a solvent. Or let
Alternatively, it is a (meth) acrylic polymer solution obtained by radical polymerization without containing it. In this case, the weight average molecular weight of the polymer is preferably in the range of 5,000 to 50,000 (category of oligomer) in consideration of the effect on the adhesiveness of the pressure-sensitive adhesive and the compatibility with the emulsion polymer. In addition, as the main raw material monomer, various kinds of (meta) described above are used.
An alkyl acrylate ester is used. In addition, the solvent used in the polymerization includes toluene, ethyl acetate, etc., and is 1 to 2 with respect to 100 parts by weight of the charged monomer.
0 parts by weight is preferred. If the amount is less than 1 part by weight, it is difficult to control heat generation during polymerization and it is difficult to obtain a solution polymerized product.
This is because if it exceeds 0 parts by weight, it becomes difficult to obtain a uniform mixture with the emulsion polymer.

The solution polymerized product can be produced, for example, by the method described in Examples below.

The pressure-sensitive adhesive of the present invention is a mixture containing the above emulsion polymer and solution polymer, and the mixing ratio of the former and the latter is 100 parts by weight of the solid content of the former from the viewpoint of adhesiveness and compatibility. The solid content of the latter is 5 to 50 parts by weight (preferably 10 to 3).
0 parts by weight). Particularly, it is preferable that the former and the latter main raw material monomers are the same from the viewpoint of compatibility.

In the aqueous emulsion type acrylic pressure-sensitive adhesive of the present invention, an acrylic polymer having a large molecular weight and excellent in cohesiveness obtained by emulsion polymerization is obtained by a solution polymerization method in which the amount of solvent is reduced as much as possible. By blending an acrylic polymer having a similar composition and a small molecular weight, it is made into a phase solution and plasticized. In particular, the initial adhesion to the human skin surface can be greatly improved.

In producing the pressure-sensitive adhesive of the present invention, according to a conventional procedure, first, aqueous ammonia is added to the emulsion polymer to neutralize the (meth) acrylic acid unit to increase the viscosity and then solution polymerization. Add the mixture and stir. In this case, various known compounding agents such as a tackifier, a filler and a coloring agent can be added as necessary.

Examples of the base material used in the present invention include Japanese paper, crepe paper, non-woven fabric, and plastic film.

The various kinds of medical adhesive tapes or sheets of the present invention can be obtained by a method of coating an adhesive on the above-mentioned substrate and drying.

[0018]

EXAMPLES Next, examples of the present invention will be shown and described more specifically, but the technical scope of the present invention is not limited by these. In the following, parts and% mean parts by weight and% by weight.

Example 1 98 parts of 2-ethylhexyl acrylate, 2 acrylates
Part, lauryl mercaptan 0.02 part, Triton X-405 (trade name, manufactured by Union Carbide Co.) 4.9 parts as an emulsifier, Neugen EA-190D as an emulsifier
(Trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.08 parts, water 71 parts,
And reacting the mixture consisting of
1 part of 28% ammonia water was added to obtain an emulsion polymer containing an acrylic polymer having a weight average molecular weight of 400,000 to 600,000.

98% 2-ethylhexyl acrylate, 2 parts acrylic acid, 0.24 parts lauryl mercaptan, AI
BN (azobisisobutyronitrile, polymerization initiator) 0.
A mixture of 016 parts and 1.88 parts of toluene was reacted under a nitrogen stream at 50 to 80 ° C. for 6 hours to obtain a solution polymer containing an acrylic polymer (solid content 9%).
8% and a weight average molecular weight of 36000) were obtained. To 100 parts of the solid content of the emulsion polymer, 15 parts of the solution polymer was added as a solid content, and the mixture was stirred for 1 hour with a stirrer to obtain an adhesive of the present invention.

Example 2 A mixture of 97 parts of 2-ethylhexyl acrylate, 3 parts of hydroxylethyl acrylate, 0.016 parts of AIBN and 1.91 parts of toluene was added at 50 to 80 ° C. under a nitrogen stream.
A solution polymer containing an acrylic polymer (solid content concentration 98%, weight average molecular weight 11,000) was obtained by reacting for 6 hours. With respect to 100 parts of the solid content of the emulsion polymer obtained in Example 1, the solution polymer as the solid content was 15 parts.
Parts and stirred for 1 hour with a stirrer to obtain an adhesive of the present invention.

Example 3 106 parts of 2-ethylhexyl acrylate, 28 parts of isobutyl acrylate, 7 parts of acrylic acid, 0.09 parts of lauryl mercaptan, Triton X-301 (trade name, manufactured by Union Carbide Co.) as an emulsifier. 8 copies, 107 water
And a mixture of 10 parts by weight of the mixture was reacted at 60 ° C. for 6 hours under a nitrogen stream, 1 part of 28% ammonia water was added, and the weight average molecular weight was 4
An emulsion polymer containing 0,000 to 600,000 acrylic polymer was obtained. To 100 parts of the solid content of this emulsion polymer, 15 parts of the solution polymer obtained in Example 1 as a solid content was added, and 1
The pressure-sensitive adhesive of the present invention was obtained by stirring for a time.

Example 4 With respect to 100 parts (solid content) of the emulsion polymer obtained in Example 3,
Add 15 parts of the solution polymer obtained in Example 2 as a solid content,
After stirring for 1 hour, the pressure-sensitive adhesive of the present invention was obtained.

Example 5 With respect to 100 parts (solid content) of the emulsion polymer obtained in Example 3,
5 parts as a solid content was added to the solution polymerized product obtained in Example 2 and stirred for 1 hour to obtain an adhesive of the present invention.

Example 6 With respect to 100 parts (solid content) of the emulsion polymer obtained in Example 3,
The solution polymerized product obtained in Example 2 was added in an amount of 50 parts as a solid content and stirred for 1 hour to obtain an adhesive of the present invention.

Example 7 100 parts butyl acrylate, 5 parts acrylic acid, 1 part lauryl mercaptan, 0.1 part AIBN, 10 parts toluene.
A solution polymerization product containing an acrylic polymer having a weight average molecular weight of 35,000 was obtained by reacting a mixture of 5 parts under a nitrogen stream at 50 to 80 ° C for 24 hours. To 100 parts (solid content) of the emulsion polymer obtained in Example 1, 15 parts of the above solution polymer was added as a solid content and stirred for 1 hour to obtain an adhesive of the present invention.

Comparative Example 1 48.4 parts of SOCTEX-CB (trade name, manufactured by SOCFIN COMPANY) as a natural rubber latex, 50 parts of styrene butadiene latex (NT-1006, manufactured by Zeon Corporation), and YS resin Px as a terpene resin.
1150N (trade name, manufactured by Yasuhara Chemical Co., Ltd.) 64.3
Part, lanolin (made by Croda Japan) 13.4 parts, toluene 20 parts, sodium polyoxyethylene lauryl ether sulfate, Santet EN (trade name, manufactured by Sanyo Chemical Co., Ltd.) 0.18 parts, polyoxyethylene octyl phenyl ether octapole An adhesive consisting of 0.25 parts of 50 (trade name, manufactured by Sanyo Kasei Co., Ltd.) and 301 parts of water was mixed at 40 ° C. to obtain an adhesive.

Comparative Example 2 A pressure-sensitive adhesive composed of the emulsion polymer prepared in Example 1.

(Evaluation Test) Examples 1 to 7 and Comparative Examples 1 to 2
Each of the pressure-sensitive adhesives obtained in 1. was applied to a mixed paper of pulp and vinylon having a basis weight of 26 g / m ² , dried at 125 ° C. for 3 minutes to remove the solvent, and 9 types of pressure-sensitive adhesive tapes (thickness of adhesive layer 35 μm) It was created. The following tests were conducted on these adhesive tapes, and the results are summarized in Table 1.

(1) Stability After storage at 40 ° C. × 75% RH for 1 month, the degree of discoloration of the pressure-sensitive adhesive layer was confirmed. Separately from this, affix it to the skin, and
It was peeled off after a lapse of time, and it was observed whether or not the glue remained on the skin. The evaluation results are displayed as follows. ○ No adhesive residue △ Slight adhesive residue × Adhesive residue

(2) Adhesive strength Adhesive tape was cut into a width of 9 mm and affixed to the inside of the upper arm.
The adhesive strength after a minute, Tensilon type tensile tester TENSIRO
N <RTA-100> (trade name, manufactured by ORIENTEC) was measured at a speed of 300 mm / min and a peeling angle of about 90 °.

(3) Gauze Fixing Property Eight-fold gauze (4 cm x 4 cm) is attached to an adhesive tape (6c).
m × 9 mm width) was crosswise applied to the lower arm, and the adhesion state after 8 hours was visually determined (sensory test). The evaluation results are displayed as follows. ○: Adhering firmly △: Peeling at the end (tape) ×: Peeling more than 1/2 (bonding area)

[Table 1]

[0033]

As described above, since the pressure-sensitive adhesive of the present invention is mainly composed of an aqueous emulsion type acrylic polymer, it can meet social needs such as environmental problems, resource saving problems, and safety and health problems. Since it has excellent aging resistance and excellent adhesiveness to the skin surface in spite of being water-based, it is suitable as various medical adhesive tapes or sheets for medical assistance or treatment.

Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location // A61K 9/70 324 A61L 15/06 (72) Inventor Takashi Kinoshita 1-1 Homozumi Shimozumi, Ibaraki-shi, Osaka No. 2 Nitto Denko Corporation

Claims (3)

[Claims] 1. An emulsion polymer obtained by using a (meth) acrylic acid alkyl ester having an alkyl group having 4 to 18 carbon atoms as a main raw material monomer, and an alkyl group having 4 to 18 carbon atoms (meth). A mixture of a solution polymerized product using an acrylic acid alkyl ester as a main raw material monomer, at least the emulsion polymerization product containing (meth) acrylic acid as a raw material monomer, and a solid content weight ratio of The solution polymer 5 to 100 parts of the emulsion polymer
Aqueous emulsion type acrylic pressure-sensitive adhesive having excellent initial adhesion of 50 parts. 2. The aqueous emulsion type (meth) acrylic pressure-sensitive adhesive according to claim 1, wherein the main raw material monomers used in the emulsion polymer and the solution polymer are the same. 3. A medical pressure-sensitive adhesive tape or sheet obtained by forming the pressure-sensitive adhesive layer comprising the aqueous emulsion-type acrylic pressure-sensitive adhesive according to claim 1 or 2 on one side or both sides of a substrate.