JPH09151365A - Solid adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition capable of preventing the change in the hardness of the surface with time without deteriorating an initial adhesive performance and good in coatability by adding sodium hyaluronate to the solid adhesive. SOLUTION: This solid adhesive composition comprises (A) a solvent, (B) an adhesive component, (C) a gelation agent, and further (D) sodium hyaluronate having a mol.wt. of 800000-3000000 as a water-retaining agent. The concentration of the component D is 0.001-0.2wt.% in the solid adhesive. The component C is preferably a pentahydric or hexahydric sugar alcohol dibenzal compound. For example, 40 pts.wt. of ethyleneglycol monoethylether as the component A, 18 pts.wt. of polyvinyl alcohol and 7 pts.wt. of polyvinyl alcohol as the component B, 3 pts.wt. of dibenzylidene sorbitol as the component C, and 1 pt.wt. of the 1% aqueous solution of the sodium hyaluronate having a mol.wt. of 1500000 are compounded to provide the solid adhesive composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid adhesive composition, and more particularly to a solid adhesive having water retention stability over time without deteriorating the initial adhesive performance.

[0002]

2. Description of the Related Art Generally, a solid adhesive is an adhesive in which an adhesive component is dissolved in a solvent and cured by a gelling agent to give a certain shape and hardness, but the solvent is volatilized with time, As a result, there is a drawback that the surface becomes hard and the beginning of application is hard and difficult to apply. In order to prevent this, polyhydric alcohols such as glycerin have been added in the past, but after a long time, the surface will become dry and hard, and it will be hard to start coating and hard to apply. However, when the solid adhesive was added, the surface drying of the solid adhesive was moderated, but the drying after the paste was applied was delayed, and the initial adhesive performance was deteriorated.

[0003]

Therefore, as a result of various studies to improve the above-mentioned drawbacks, the present inventor can solve the problem by adding sodium hyaluronate having a moisturizing effect to a solid adhesive. The present invention has been completed, and the object of the present invention is to provide a solid adhesive having water retention stability over time without deteriorating the initial adhesive performance.

[0004]

The gist of the present invention is to provide a solid adhesive comprising a solvent, an adhesive component and a gelling agent, which contains sodium hyaluronate having a molecular weight of 800,000 to 3,000,000 as a water retention component. It is a solid adhesive composition characterized by the above.

That is, in the present invention, the inclusion of sodium hyaluronate having a moisturizing effect in the solid adhesive eliminates the increase in surface hardness due to the change with time, and retains the water retention over time without lowering the initial adhesive performance. , And the surface does not dry, so that a solid adhesive having stable coating performance can be obtained.

The present invention will be described in detail. The adhesive component used in the present invention is not different from the adhesive component of the conventional solid adhesive, and examples thereof include polyvinylpyrrolidone, polyvinyl alcohol, and (meth) acrylic acid hydroxyester.

The gelling component used in the present invention is a dibenzal compound of a sugar alcohol having a valence of 5 to 6. The 5 to 6 sugar alcohol dibenzalides include, for example, mannitol, rhamnitol, xylitol, sorbitol, and the like.
A dibenzal compound obtained by reacting a hexavalent sugar alcohol with benzaldehyde or a nuclear substitution product thereof in the presence of an acid catalyst, which may be used alone or in a mixture with each other, or a small amount of the above-mentioned monosaccharide sugar sugar. Alternatively, it is used in the form of a mixture with tribenzal compound. Particularly good excipients are xylitol, sorbitol or a dibenzal compound of a mixture thereof.

A mixture of water and an organic solvent is used as a solvent component. The organic solvent may be any of alcohols, ethers, ketones, hydrocarbons and the like which are usually used as a solvent, and these may be used alone or in combination. Specific preferred organic solvents include ethanol, isopropanol, acetone, tetrahydrofuran, ethylene glycol, methyl cellosolve, ethyl cellosolve, ethylene glycol, monoisopropyl ether, ethylene glycol monoethyl ether, petriol, etc., and these solvents are mixed and used. May be. In the present invention, the reason for using a mixture of water and an organic solvent as a solvent is to add water to an organic solvent solution of a gelling agent having an oleophilic organic lipophilic property, in order to achieve gelation. The ratio of both is 1
The range is 0:90 to 90:10. Preferably 30:
The range is 70 to 70:30.

In the present invention, the solid adhesive consisting of the above-mentioned adhesive component, gelling component and solvent has a molecular weight of 800,000-3.
With the addition of, 000,000 sodium hyaluronate, the addition of sodium hyaluronate solution does not reduce the initial adhesion performance, increases water retention over time, makes the surface hard to dry and hard, and provides stable coating performance. Is obtained. The molecular weight of hyaluronic acid contained is 800,000 to 3
When the molecular weight is less than 800,000, the water retention effect is reduced, and when the molecular weight is more than 3 million, it is difficult to mix in the adhesive. The concentration of sodium hyaluronate contained in the solid adhesive may be a small amount, for example, 0.001 to
0.2 wt% is sufficient. Sodium hyaluronate is added as an aqueous solution, but since the aqueous solution of sodium hyaluronate has a high viscosity, it is usually 0.1% as a 1% aqueous solution concentration.
Add about 20 wt%. 0.1 wt as a 1% aqueous solution
If the added amount is less than%, it is not possible to expect a remarkable effect on the water retention of sodium hyaluronate.
Adding more than 0 wt% also reduces the initial adhesive performance,
The shapeability of the paste is also poor. Furthermore, in addition to the above components, the solid adhesive according to the present invention may contain additives usually added to the adhesive, such as fillers, fragrances, and coloring agents.

Usually, the solid adhesive is produced by heating and mixing so as to obtain a homogeneous mixture of at least the above-mentioned three components. In the present invention, these three components are added in the form of an aqueous sodium hyaluronate solution. It is preferable. However, as far as possible, there is no particular limitation on the mixing method itself for the mixing means. Then, the mixture is mixed with the above components by a means such as a heating pot equipped with a stirring blade, a Banbury mixer, a Brabender plastograph, etc., and the mixture is melted and then cast-molded or a screw-type extruder. Therefore, a method of cooling and solidifying after extrusion can be adopted.

[0011]

[Examples and Comparative Examples]

Example 1 To a three-necked flask equipped with a stirrer, 18 parts of polyvinylpyrrolidone as an adhesive component and 7 parts of polyvinyl alcohol were added to a solvent component consisting of 31 parts of water and 40 parts of ethylene glycol monoethyl ether, and dibenzylidene sorbitol 3 as a gelling agent. Parts, 1 part of a 1% aqueous solution of sodium hyaluronate having a molecular weight of 1,500,000 is added and dissolved by stirring, and the whole is stirred to form a sol state having fluidity and good transparency. A solid adhesive was obtained by allowing the transparent liquid to cool.

Comparative Examples 1 to 5 In the same manner as in Example 1, the compounding ingredients shown in Table 1 were mixed to produce solid adhesives. In addition, the compounding ratio in the case of Example 1 is also described. The solid adhesives obtained in Examples and Comparative Examples were examined for hardness, initial adhesion time and coating property. Table 2 shows the results. The test method was as follows. Hardness: The hardness of the paste was measured using RHEO METER RUD-J (manufactured by Fuji Science Co., Ltd.). The higher the value, the harder it is. Initial adhesion time: 25 x 25 of 85 g / m ² kraft paper
Glue is applied to the adhesive surface of mm, and the same kraft paper is pressed well with a hand roller. After press-bonding, the paper is peeled off to indicate the time when the adhesive failure of the paper begins. Applicability: A solid adhesive with a diameter of 17 mm is placed on kraft paper with a load of 500 g, and the degree of shape deformation when the paper is towed at a speed of 5 mm / sec is visually judged to be good or bad. The evaluation was made in four stages of a>b>c> d.

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

As described above, in the present invention, by incorporating sodium hyaluronate having a specific molecular weight in the solid adhesive, the initial adhesive performance is not deteriorated as seen in the examples. A change in surface hardness over time was suppressed, and a solid adhesive having good coatability could be obtained.

Claims (3)

[Claims] 1. A solid adhesive composition comprising a solvent, an adhesive component and a gelling agent, wherein sodium hyaluronate having a molecular weight in the range of 800,000 to 3,000,000 is contained as a water retention component. Stuff. 2. The solid adhesive composition according to claim 1, wherein the concentration of sodium hyaluronate in the solid adhesive is 0.001 to 0.2 wt%. 3. A solid adhesive composition in which the gelling agent is a dihydric alcohol alcohol having a valence of 5 to 6.