JPH1081854A - Antibacterial hot melt acrylic adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antibacterial hot melt acrylic adhesive made capable of the abridgement of a process on account of its assured antibacterial properties and antimold properties by copolymerizing a vinyl monomer mixture based on acryl (meth)acrylate with a macromonomer and a specified vinyl compound. SOLUTION: This adhesive is prepared by copolymerizing 100 pis.wt. vinyl monomer mixture based on acryl (meth)acrylate with 3-35 pis.wt. macromonomer and 0.5-35 pts.wt. vinyl compound represented by formula I (wherein n=9, 13 or 17) or formula II and adding various additives to the obtained copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an antibacterial acrylic hot melt adhesive which can be suitably used for assembling sanitary materials such as disposable diapers and sanitary napkins.

[0002]

2. Description of the Related Art Hot melt adhesives are generally used for assembling sanitary materials such as disposable diapers and sanitary napkins. These sanitary materials receive body wastes, excrement such as manure, physiological wastes and the like, and after absorption of the wastes, the environment of the site in contact with the wastes becomes unsanitary. In particular, as in the case of diapers for infants and the disabled, if they are left for a long time in this state because they cannot be replaced by themselves, there is a very high possibility that molds and bacteria will propagate, which is very unsanitary.

In view of the above problems, Japanese Patent Application Laid-Open No. 61-2720 discloses
No. 50 proposes an absorbent article in which silver-containing glass powder containing phosphoric acid as a main component is dispersed on the inner surface and outer surface of a paper diaper to impart sterilization and antibacterial functions.

However, the absorbent article described in Japanese Patent Application Laid-Open No. 61-272050 has a step of spraying and dispersing an antibacterial / antifungal agent in the step of producing a cotton-like pulp from a pulp sheet for imparting antibacterial / antifungal properties. This not only complicates the process but also increases the manufacturing cost of the product.

The inventors of the present invention have studied diligently to provide antibacterial and antifungal properties and to simplify the process, and have developed an acrylic hot melt adhesive which is used by spray coating when assembling paper diapers. The inventors attempted to solve the above problem by imparting antibacterial and antifungal properties to the agent, and completed the present invention.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an antibacterial acrylic hot melt adhesive which can reliably provide antibacterial and antifungal properties and can simplify the process. It is in.

[0007]

SUMMARY OF THE INVENTION The present invention provides a vinyl monomer 100 containing an alkyl (meth) acrylate as a main component.
Parts by weight, 3 to 35 parts by weight of macromonomer and the following formula (1) or (2)

Embedded image

Embedded image An antibacterial acrylic hot melt adhesive comprising 0.5 to 35 parts by weight of a vinyl compound represented by the formula:

The alkyl (meth) acrylate, which is the main component of the vinyl monomer used in the present invention, is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl ( (Meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, and the like. These can be used alone or in combination.

The vinyl monomer other than the above-mentioned alkyl (meth) acrylate is not particularly limited. For example, acrylic acid, methacrylic acid, dimethylaminoethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (Meth) acrylate, phenoxyethyl (meth) acrylate, (meth) acrylamide, dimethyl (meth) acrylamide, diethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, butoxymethyl (meth) acrylamide, diacetone (meth)
Acrylamide, 2- (meth) acrylamido-2-methylpropanesulfonic acid, (meth) acrylsulfonic acid, oxyethyl (meth) acrylate phosphate, N-vinylpyrrolidone and the like can be mentioned. The amount of the vinyl monomer other than the alkyl (meth) acrylate is preferably 20% by weight or less based on the total amount of the vinyl monomer. If the amount exceeds 20% by weight, the adhesive strength of the obtained antibacterial acrylic hot melt adhesive tends to decrease.

The macromonomer used in the present invention is not particularly limited. For example, US Pat.
And macromonomers which can be produced by the methods disclosed in JP-A-86116, JP-A-3842059 and JP-A-60-133007. As these macromonomers, specifically, polystyrene and its derivatives, polymethyl methacrylate and its derivatives, styrene-acrylonitrile copolymer and the like are suitably used.

The amount of the macromonomer is limited to 3 to 35 parts by weight based on 100 parts by weight of the vinyl monomer. When the amount is less than 3 parts by weight, the initial cohesive strength of the obtained antibacterial acrylic hot melt adhesive is reduced. When the amount is more than 35 parts by weight, the melt viscosity becomes too high, resulting in poor applicability and adhesion. descend.

The vinyl compound used in the present invention has the following formula (1) or (2)

Embedded image

Embedded image And exhibits antibacterial and antifungal properties as a copolymer obtained by copolymerizing with a vinyl monomer and a macromonomer containing the alkyl (meth) acrylate as a main component. As the vinyl compound represented by the above formula (1), dimethyldecyl-4-vinylbenzylphosphonium chloride (n = 9), dimethyltetradecyl-4-vinylbenzylphosphonium chloride (n = 13), dimethyloctadecyl-4- And dimethylalkyl-4-vinylbenzylphosphonium chloride such as vinylbenzylphosphonium chloride (n = 17). The vinyl compound represented by the above formula (2) is 2-ethyl methacrylate tri-n-butylphosphonium chloride.

The amount of the vinyl compound represented by the above formulas (1) and (2) is limited to 0.5 to 35 parts by weight based on 100 parts by weight of the vinyl monomer. When the amount is less than 0.5 part by weight, the antibacterial and antifungal properties are not sufficiently exhibited. On the other hand, when the amount exceeds 35 parts by weight, the melt viscosity of the obtained antibacterial acrylic hot melt adhesive becomes too high, and the applicability and the adhesiveness are reduced.

The antibacterial acrylic hot melt adhesive of the present invention may be a solvent-type acrylic hot melt adhesive obtained by copolymerizing the above components in a solvent and removing the solvent.
Further, a block polymerization type acrylic hot melt adhesive by ultraviolet irradiation may be used.

If necessary, a heat stabilizer, an antioxidant, a plasticizer, a tackifier, a filler, and the like may be added to the antibacterial acrylic hot melt adhesive of the present invention. Examples of the heat stabilizer include dioctadecylpentaerythritol diphosphite, ditridecylpentaerythritol diphosphite, bis (2-t-butyl-4-methylphenyl) pentaerythritol diphosphite, and bis (2,6-di t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, triphenylphosphite, tris (monononylphenyl) phosphite, bis (dinonylphenyl) monononylphenylphosphite Phosphite compounds such as phytite, bis (monononylphenyl) dinonylphenyl phosphite, diphenyloctyl phosphite, and diphenyldecyl phosphite are exemplified, and are preferably used.

The antibacterial acrylic hot melt adhesive of the present invention is obtained by converting the vinyl compound having the antibacterial and antifungal functions represented by the above formulas (1) and (2) to the alkyl (meth)
As it is used as a copolymer obtained by copolymerizing with vinyl monomers and macromonomers containing acrylate as a main component, it can reliably demonstrate antibacterial and antifungal properties to sanitary materials such as paper diapers and sanitary napkins over a long period of time. The antibacterial and antifungal properties can be imparted to the sanitary material without adding a special step of imparting an antibacterial and antifungal function.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention are shown below, but the present invention is not limited to these examples.

(Examples 1 to 8 and Comparative Examples 1 to 8) (Preparation of antibacterial acrylic copolymer) Ethyl acetate 100 was placed in a separable flask equipped with a cooling tube, a thermometer and a stirrer.
Parts by weight, and a copolymerization component such as a vinyl monomer and a macromonomer containing an alkyl (meth) acrylate as a main component and a vinyl compound represented by the formula (1) and / or the formula (2) shown in Tables 1 and 2. The specified amount by weight was added, and n-dodecanethiol 0.1 as a chain transfer agent was further added.
Parts by weight, and the mixture was uniformly mixed and then heated. Under the reflux of ethyl acetate, 0.01 parts by weight of a polymerization initiator azobisisobutyronitrile was added dropwise every hour, and a polymerization reaction was carried out for 6 hours. 1 and Table 2 were prepared. Weight average molecular weight (Mw) of the obtained copolymer
Was measured by a gel permeation chromatography (GPC) method and expressed as a molecular weight in terms of polystyrene.

(Preparation of Antibacterial Acrylic Hot Melt Adhesive) After the solvent of the obtained copolymer solution was volatilized, 100 parts by weight of the antibacterial acrylic copolymer was added in the amounts shown in Tables 1 and 2. Each additive is blended, and under nitrogen atmosphere, 150
The mixture was heated and kneaded at 4 ° C. for 4 hours to prepare an antibacterial acrylic hot melt adhesive.

In the preparation of the antibacterial acrylic copolymer and the antibacterial acrylic hot melt adhesive, the monomers and additives used are shown in Table 1 and Table 2 in the column of copolymer composition and the column of compounding composition. As shown, abbreviations are used for monomer names and the like as follows.

(Monomers) BA: n-butyl acrylate 2EHA: 2-ethylhexyl acrylate MMA: methyl methacrylate Macromer: manufactured by Shin Nihon Rika Co., Ltd., trade name "Macromer 13"
K-PSMA "Vinyl compound A: dimethyldecyl-4-vinylbenzylphosphonium chloride Vinyl compound B: dimethyltetradecyl-4-vinylbenzylphosphonium chloride Vinyl compound C: dimethyloctadecyl-4-vinylbenzylphosphonium chloride Vinyl compound D: 2- Ethyl methacrylate tri-n-butylphosphonium chloride

(Additives) Heat stabilizer A: dioctadecyl pentaerythritol diphosphite Heat stabilizer B: ditridecyl pentaerythritol diphosphite Tackifying resin: trade name "YS resin S-145" manufactured by Yashara Chemical Co., Ltd. Terpene phenolic resin

In order to evaluate the performance of the antibacterial acrylic hot melt adhesives obtained in Examples and Comparative Examples, antibacterial activity, melt viscosity, cohesive strength and adhesive strength were tested by the following methods. Tables 1 and 2 show the test results and the comprehensive evaluation performed based on the test results.

1. Antibacterial activity: Antibacterial activity was measured by a commonly used solution dilution method. First, physiological saline 1
In 8 ml, 10 ⁷ E. coli (Escheric
hia coli IFO 3806) was uniformly mixed and suspended, and 2 ml of the pseudo-filtration was spray-coated on a nonwoven fabric having a size of 100 mm x 100 mm at a ratio of 1 g of the above-mentioned antibacterial acrylic hot melt adhesive, and cut to a size of 10 mm x 10 mm.
, And incubated for 24 hours, and the growth rate of the bacteria was evaluated as follows: ○: no bacterial growth, Δ: slight bacterial growth, ×: bacterial growth almost all over the test specimen , According to the criteria of.

2. Melt viscosity: Using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.), using a rotor # HH4, and rotating at 2.
The melt viscosity at 190 ° C. was measured at 5 rpm.

3. Cohesion: 10 mm x 10 mm x 10 m
A test piece of antibacterial acrylic hot melt adhesive cut into m-square was attached to an aluminum plate with a pressing force of 2 kg,
The specimen was held vertically in an oven at 80 ° C. for 12 hours, and the sag length of the test piece was measured as a cohesive force.

4. Adhesive strength: two pieces 1.5 mm thick x 2 width
190 ° C. between polyethylene plates of 0 mm × length 70 mm
The antibacterial acrylic hot melt adhesive melted in step 1 was applied to a thickness of 1 mm × width of 20 mm × length of 10 mm, and a 2 kg roller was pasted and reciprocated from two polyethylene plates to form a test piece. 2 at a pulling speed of 50 mm / min.
The shear tensile strength at 3 ° C. was measured as the adhesive strength.
In Tables 1 and 2, those in which a horizontal bar is drawn in the corresponding column are those that could not be measured.

5. Overall evaluation: “○” indicates that all of the test results in the above items 1 to 4 are satisfactory,
Those that could be used by taking some auxiliary means were rated "△", and those that were completely unsatisfactory were rated "x".

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

Since the antibacterial acrylic hot melt adhesive of the present invention is constituted as described above, it can surely exhibit antibacterial and antifungal properties over a long period of time, and it is particularly antibacterial and antifungal. Antibacterial and antifungal properties can be imparted to sanitary materials without adding a step of imparting a mold function, so that paper diapers, sanitary napkins and the like having antibacterial and antifungal properties can be easily and at low product cost. Disposable products or members such as bed pad components can be assembled.

Claims (1)

[Claims] 1. 100 parts by weight of a vinyl monomer containing an alkyl (meth) acrylate as a main component, macromonomer 3
~ 35 parts by weight and the following formula (1) or (2) Embedded image An antibacterial acrylic hot melt adhesive comprising 0.5 to 35 parts by weight of a vinyl compound represented by the formula: