JP3292003B2 - Aqueous adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous pressure-sensitive adhesive composition, and more particularly, to an aqueous pressure-sensitive adhesive composition having high adhesive strength and excellent feeling in use.

[0002]

2. Description of the Related Art Conventionally, a patch has been used which is provided with a pressure-sensitive adhesive layer having adhesiveness on one side of a support and containing water. Such a patch is required to be held on the skin for a predetermined time without peeling off from the skin surface, and at the same time, it is necessary to adhere to the skin, thereby providing a sense of incongruity and excellent usability. Products. Therefore, the pressure-sensitive adhesive layer is required to have a somewhat strong adhesive force.

However, if the adhesive force of the adhesive layer is too large, the following problems occur. For example, when the patch is peeled off, the hair is peeled off and the pain is felt, and the skin is highly irritating, and the skin is easily irritated. Furthermore, a base having a large adhesive strength has a high viscosity, and has a problem in productivity.

Conversely, when the adhesive strength of the adhesive layer is reduced,
Although the hair on the skin is peeled off and the irritation to the skin is reduced, such a patch is easily peeled off from the skin surface and is extremely poor in usability.

[0005] The present invention has been made in view of the above circumstances,
An object of the present invention is to provide an aqueous pressure-sensitive adhesive composition that has an appropriate adhesive strength, does not cause discomfort to the skin, is excellent in usability, and has little skin irritation.

[0006]

Means for Solving the Problems and Embodiments of the Invention The present inventors have found that the adhesive strength of the aqueous pressure-sensitive adhesive composition is not uncomfortable when applied to the skin, has an appropriate level of tackiness, As a result of diligent research on an aqueous adhesive composition with little irritation, as a crosslinked product of polyacrylic acid and polyacrylate, polyacrylic acid having various molecular weights and polyacrylate are used together, and at 25 ° C. 1% by weight in
The inventors have found that the above object can be effectively achieved by further blending a cellulose derivative having a viscosity of an aqueous solution of 1,000 to 4,000 cps and / or a salt thereof, and have accomplished the present invention.

Hereinafter, the present invention will be described in more detail.

The aqueous pressure-sensitive adhesive composition according to the present invention is a water-based pressure-sensitive adhesive composition containing a crosslinked product of polyacrylic acid and polyacrylate, wherein (A) the weight-average molecular weight is 50,000 to 300,000. Polyacrylic acid and / or a salt thereof,
(B) polyacrylic acid and / or a salt thereof having a weight average molecular weight of 500,000 to 2,000,000, and (C) polyacrylic acid and / or a salt thereof having a weight average molecular weight of more than 2,000,000 and 10,000,000 or less. And (D) the viscosity of a 1% by weight aqueous solution at 25 ° C. is 1000 to 4000 cp.
The aqueous adhesive base is obtained by blending a cellulose derivative of s and / or a salt thereof, which has no uncomfortable feeling on the skin, has appropriate adhesive strength, and has little skin irritation.

Here, the total amount of the cellulose derivative and / or the salt of the cellulose derivative is 0.1 to 1% of the whole composition.
0% (% by weight, the same applies hereinafter), particularly preferably 0.5 to 5%. If it is less than 0.1%, the adhesive strength may be insufficient. If it exceeds 10%, the viscosity of the composition becomes high. In some cases, a problem may occur in terms of manufacturability. In addition, a cellulose derivative or salt partially neutralized so that the cellulose derivative salt has the above-mentioned amount may be used.

As the cellulose derivative and the cellulose derivative salt of the present invention, any of them can be used. For example, carboxymethyl cellulose and its alkali metal salts, hydroxymethyl cellulose, hydroxyethyl cellulose,
One or more of hydroxypropylcellulose, methylcellulose and the like can be used, and particularly, alkali metal salts of carboxymethylcellulose such as sodium carboxymethylcellulose and potassium carboxymethylcellulose can be suitably used.

Further, the polyacrylic acid of the aqueous pressure-sensitive adhesive base is not particularly limited in the form such as linear or molecular chain.
Further, in addition to a polymer obtained by polymerizing ordinary acrylic acid, a partially crosslinked acrylic acid polymer such as Carbopol (trade name, manufactured by Goodrich Corporation in the United States) may be suitably used.

Examples of polyacrylates include monovalent metal salts of polyacrylic acid such as sodium polyacrylate and potassium polyacrylate, monoethanolamine polyacrylate, diethanolamine polyacrylate, triethanolamine polyacrylate. One or more of polyacrylic acid amine salts and polyacrylic acid ammonium salts can be suitably used.

In the present invention, the polyacrylic acid and the polyacrylate have a weight average molecular weight of 50,000 to 30.
10,000 polyacrylic acid and / or polyacrylate (low molecular weight) and polyacrylic acid and / or polyacrylate (high molecular weight) having a weight average molecular weight of 500,000 to 2,000,000
And the weight average molecular weight is more than 2,000,000 and 10,000,000 or less,
Preferably 3 to 7 million polyacrylic acid and / or
Alternatively, a polyacrylate (ultra-high molecular weight substance) is used in combination, whereby the object of the present invention is effectively achieved.

In a more preferred embodiment, polyacrylic acid is used as the low molecular weight compound and the high molecular weight compound, and polyacrylate is used as the ultrahigh molecular weight compound.

The amount of the high molecular weight polyacrylic acid / salt having an average molecular weight of 500,000 to 2,000,000 is preferably 0.3 to 10%, more preferably 0.5 to 7%, of the whole composition. on the other hand,
The blending amount of the low molecular weight polyacrylic acid / salt having an average molecular weight of 50,000 to 250,000 is 0.3 to 10% of the whole composition, particularly 0.1 to 1.0%.
Preferably, it is set to 5 to 7%. The mixing ratio (weight ratio) of the high molecular weight and low molecular weight polyacrylic acid / salt is 1: 1.
It is preferably from 0 to 10: 1, more preferably from 1: 8 to 8:
It is one. If these compounding amounts and ratios are outside the above ranges, sufficient adhesive strength cannot be obtained. The amount of the ultrahigh molecular weight compound is preferably from 0.3 to 5%, particularly preferably from 0.5 to 3%, and more preferably from 5 to 100 parts by weight of the total amount of the low molecular weight compound and the high molecular weight compound. ~ 50 parts by weight, especially 10 ~
It is preferably 35 parts by weight. If the compounding amount and the compounding ratio of the ultrahigh molecular weight compound are out of the above ranges, problems occur in the productivity and the adhesiveness.

The mixing ratio (weight ratio) of polyacrylic acid and polyacrylate is from 1:10 to 10: 1, more preferably from 1: 8 to 8: 1, and still more preferably from 1: 4 to 4: 1
However, it is also possible to use a material in which polyacrylic acid or a salt is partially neutralized so that the polyacrylate has the above ratio. The total blending amount of polyacrylic acid and polyacrylate is 0.5% of the whole composition.
-20%, preferably 1-15%,
If it is less than 5%, the adhesive strength may be insufficient, and if it is more than 20%, the adhesive strength may be high, causing pain when peeled off, and causing problems in terms of usability and skin irritation.

Here, the aqueous pressure-sensitive adhesive base of the present invention uses a cross-linked polyacrylic acid and polyacrylate by adding an appropriate cross-linking agent. The type of is not particularly limited as long as the polyacrylic acid and the polyacrylate can be cross-linked, but a polyvalent metal compound is particularly preferably used. In this case, as the polyvalent metal compound, a magnesium compound, a calcium compound, a zinc compound, a cadmium compound, an aluminum compound, a titanium compound, a tin compound, an iron compound,
Although a chromium compound, a manganese compound, a cobalt compound, a nickel compound and the like can be used, the aqueous pressure-sensitive adhesive composition of the present invention is applied to the skin, and if safety to the skin is considered, an aluminum compound, a magnesium compound It is particularly preferable to use calcium compounds and the like.

In this case, any of the aluminum compound, magnesium compound and calcium compound can be suitably used. For example, alums such as potassium alum, ammonium alum, iron alum, aluminum hydroxide, aluminum sulfate, aluminum chloride, aluminum chloride Glycinate, aluminum acetate, aluminum oxide, synthetic aluminum silicate, aluminum metasilicate, calcium hydroxide, calcium carbonate, calcium sulfate, calcium nitrate, calcium chloride, calcium acetate, calcium oxide, calcium phosphate, magnesium hydroxide, magnesium carbonate, sulfuric acid Magnesium, magnesium acetate, magnesium silicate, magnesium oxide,
One or more of water-soluble compounds such as alumina / magnesium hydroxide, magnesium metasilicate aluminate, magnesium aluminate silicate, synthetic hydrotalcite, and double salts containing these metals, and poorly water-soluble compounds may be used. In addition, an antacid containing aluminum and magnesium may be blended as the polyvalent metal compound.

The preferred amount of the crosslinking agent varies depending on the type of the crosslinking agent. For example, when the polyvalent metal compound is used, the amount is preferably 0.001% of the whole composition.
It is preferably set to 10 to 10%, particularly preferably 0.01 to 5%.

In addition, a polyhydric alcohol can be added to the aqueous pressure-sensitive adhesive base of the present invention as long as the effect of the present invention is not impaired. For example, glycerin, sorbitol,
One or more of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, maltitol, xylitol and the like can be used.
In addition, when adding a polyhydric alcohol, it is preferable that the compounding quantity is 50% or less of the whole composition.

Next, a cooling agent may be added to the pressure-sensitive adhesive composition of the present invention. The type of the cooling agent is not limited as long as it is a substance that provides a refreshing sensation. Examples of such a cooling agent include l-menthol, N-substituted-p-menthan-3-carboxamide, and 3-substituted- p-menthane, 2- or 3-substituted-p-menthane-3-carboxamide, 3-substituted-p-menthane, 2- or 3-substituted-p
-Menthanediol, trialkyl-substituted cyclohexanecarboxyamide and the like.
Species can be used alone or in combination of two or more. Among them, l-menthol is particularly preferred because it gives a strong refreshing feeling, and l-menthol is used alone.
Or it is desirable to use it in combination with another cooling agent.
When using l-menthol, l-menthol itself may be blended, and it may be blended as it is in the essential oil as a fragrance component, for example, as peppermint oil. Is also good.

The amount of the cooling agent is preferably 0.001 to 5%, more preferably 0.01 to 2% of the whole composition.

The aqueous pressure-sensitive adhesive composition of the present invention may optionally contain, in addition to the above-mentioned components, other components usually added to a compress sheet or the like, as long as the effects of the present invention are not impaired. You can also. However, the compounding of the medicinal component is not essential.

The aqueous pressure-sensitive adhesive composition of the present invention is used as an external preparation. For example, when it is used as a compress sheet, the above components and other components are mixed with water and kneaded well, if necessary. A paste is prepared, applied to a backing such as paper, woven fabric, non-woven fabric, plastic film and the like, and if necessary, coated with a facing such as a polyethylene film to obtain a product.

The preferred embodiments of the present invention are as follows. In an aqueous pressure-sensitive adhesive composition containing a crosslinked product of polyacrylic acid and polyacrylate, (A) polyacrylic acid having a weight average molecular weight of 50,000 to 300,000 and / or a salt thereof 0.3 to 10 weight (B) 0.3 to 10% by weight of polyacrylic acid and / or a salt thereof having a weight average molecular weight of 500,000 to 2,000,000, and (C) a weight average molecular weight of more than 2,000,000 to 10,000,000 or less. (D) a 1% by weight aqueous solution at 25 ° C. having a viscosity of 1000
An aqueous pressure-sensitive adhesive composition comprising a cellulose derivative of up to 4000 cps and / or a salt thereof.

[0026]

According to the present invention, it is possible to obtain an aqueous pressure-sensitive adhesive composition which has an appropriate adhesive strength when applied to the skin and has little skin irritation.

[0027]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following examples, the viscosity of sodium carboxymethylcellulose indicates the viscosity of a 1% by weight aqueous solution at 25 ° C. The average molecular weight of polyacrylic acid / salt is a weight average molecular weight.

[0028] EXAMPLES Table 1 and sufficiently stirred to a paste placed in a mixer the components shown by preparing an aqueous adhesive composition, which to be 150 g / m ² on the nonwoven The coating was uniformly applied and facing the polyethylene film to produce a compress sheet. The adhesive strength of each compress sheet was evaluated in accordance with the JIS ball tack adhesive strength test method. The results are also shown in Table 1.

<Ball tack adhesion test method>
The ball rolling device used in SZ0237-1980 was used, and the inclination angle was 30 °. JIS G 4805
The size of the ball of the material specified in JIS B15
A total of 3 from 1/16 to 1 of the "call of ball" of 01
One type was used, and a numerical value that was 32 times the “nominal of the ball” was called a ball number, and was used as an index of the adhesive strength. A test piece was attached at a predetermined position on the inclined plate of the ball rolling device with the adhesive surface facing upward, and balls of various sizes were set on the gate. When the gate is slowly opened and the ball rolls, find the largest ball that stops completely (the ball does not move for more than 5 seconds) in the measuring section, and uses the ball number at that time as an index of adhesive force. And

[0030]

[Table 1]

<Skin Irritation> The compressive sheet of the example was applied to the upper arm of 20 healthy persons, and the skin irritation was evaluated by a closed patch test for 24 hours. As a result, skin irritation was observed in all cases. No skin irritation was observed.

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Claims (1)

(57) [Claims] 1. An aqueous pressure-sensitive adhesive composition containing a crosslinked product of polyacrylic acid and polyacrylate, comprising: (A) polyacrylic acid having a weight average molecular weight of 50,000 to 300,000 and / or a salt thereof; (B) polyacrylic acid and / or a salt thereof having a weight average molecular weight of 500,000 to 2,000,000, and (C) polyacrylic acid and / or a salt thereof having a weight average molecular weight of more than 2,000,000 and 10,000,000 or less. And (D) a 1% by weight aqueous solution at 25 ° C. having a viscosity of 1000
An aqueous pressure-sensitive adhesive composition comprising a cellulose derivative of up to 4000 cps and / or a salt thereof.