JP3288813B2 - Coating agent and fibrous cotton coated therewith - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating agent for imparting antibacterial properties, water-absorbing and moisture-permeable properties and the like to fibers, and a fiber cotton coated with the coating agents.

[0002]

2. Description of the Related Art Conventionally, various coating processes have been applied to fabrics made of synthetic fibers or natural fibers to impart properties such as waterproofness, windproofness, water repellency, and flame retardancy. . By the way, recently, antibacterial processing for imparting antibacterial performance to textile cotton has attracted attention. However, antibacterial agents having excellent antibacterial performance often have a problem in safety to the human body. In order to improve this problem, attempts have been made to use chitosan, which is a natural polymer having no safety problems. It is intended to impart antibacterial performance to fiber cotton by coating a fiber coating with a coating agent obtained by dispersing chitosan in a resin capable of forming a film, and then drying to form a coating layer. It is assumed that. It is important for such a coating agent that chitosan is uniformly dispersed in the coating agent in order to provide a product having a certain quality of antibacterial performance.

[0003] However, when a solution type resin dissolved in an organic solvent is used as a resin having a film forming ability, chitosan is not uniformly dispersed in a coating agent because chitosan is insoluble in the organic solvent. However, the dispersion state of chitosan in a coating layer formed using such a coating agent became uneven, and the antibacterial performance of the obtained product was likely to vary. Further, when trying to uniformly disperse chitosan, the resin having a film forming ability to be used is limited to a water-soluble type or an emulsion type. In that case, a large amount of water in the coating agent required a large amount of heat energy in the drying step, and a long time was required for drying, so that the processing ability was extremely low. Further, if the drying temperature is too high in order to shorten the drying time, water is bumped and a uniform coating layer cannot be formed, resulting in a problem that the antibacterial performance of the obtained product varies. .

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to provide a coating agent which is very safe, has a uniform dispersion of chitosan, and has an excellent coating processing ability. Another object of the present invention is to provide a fiber cotton having a certain quality of antibacterial performance.

[0005]

Means for Solving the Problems Claim 1 of the present invention
In the coating agent described above, the solution of the above-mentioned problem is to dissolve a chitosan-containing synthetic resin obtained by salting out a synthetic resin emulsion with a chitosan acid aqueous solution in an organic solvent.

Further, in the case of the coated cotton fabric according to the present invention, the coating agent of the present invention is coated on the cotton fabric and dried to form a coating layer. The solution.

The present inventors salt out a synthetic resin emulsion with an aqueous solution of chitosan acid to obtain a chitosan-containing synthetic resin in which chitosan is uniformly dispersed in the synthetic resin, and further dissolve the chitosan-containing synthetic resin in an organic solvent. It became a light brown transparent liquid, and it was found that chitosan was obtained in a very fine particle and uniformly dispersed,
The inventors of the present invention have found that the above problem can be effectively solved by using this as a coating agent, and have completed the present invention.

Hereinafter, the present invention will be described in detail. The coating agent of the present invention is obtained by washing a chitosan-containing synthetic resin with water, drying it, and dissolving it in an organic solvent. The chitosan-containing synthetic resin is obtained by salting out a synthetic resin emulsion with an aqueous solution of chitosan acid,
Chitosan is uniformly dispersed in the synthetic resin. In the present invention, the synthetic resin emulsion may be any one that is suitable as a fiber coating processing agent when salted out with an aqueous chitosan acid solution, washed with water, dried, and further dissolved in an organic solvent. The emulsion may be produced by any method, for example, an acrylic emulsion obtained by an emulsion polymerization method, a vinyl acetate emulsion, a styrene emulsion, a vinyl chloride emulsion, a butadiene emulsion, a copolymer emulsion thereof, and a synthetic resin obtained by post-emulsification. Emulsions are used, and one or more synthetic resin emulsions are appropriately selected from these depending on the purpose, and acrylic resins are particularly preferable.

[0009] The chitosan acid aqueous solution is obtained by dissolving chitosan in an acid. Chitosan is a basic polysaccharide obtained by treating the chitin of crustaceans such as crabs and shrimps with concentrated alkali and deacetylating it.It has antibacterial properties, biodegradability, water absorption and moisture permeability, biocompatibility It is a very safe natural polymer having unique properties such as properties. Acids used to obtain the chitosan acid aqueous solution include formic acid,
Organic acids such as acetic acid, propionic acid, lactic acid, citric acid, ascorbic acid, adipic acid, and L-glutamic acid; and inorganic acids such as hydrochloric acid.

As an example of an operation for salting out the synthetic resin emulsion with an aqueous solution of chitosan acid, the synthetic resin emulsion is diluted with water or the like as necessary, and then heated to 40 to 95 ° C. Next, the above-mentioned aqueous solution of chitosan acid was added dropwise to the heated synthetic resin emulsion.
, And then cooled. In this case, the synthetic resin is deposited. Then, the precipitated synthetic resin is separated from the aqueous solution, washed with water until neutral, and dried to obtain a chitosan-containing synthetic resin in which chitosan is uniformly dispersed in the synthetic resin. In this salting-out operation, the chitosan acid aqueous solution alone may be used, or another salting-out agent may be used in combination. As other salting-out agents, inorganic salts such as calcium chloride, aluminum sulfate, sodium chloride, magnesium chloride, magnesium sulfate and magnesium chloride can be used.

In the chitosan-containing synthetic resin, the content of chitosan with respect to the synthetic resin is preferably 1% by weight or more. If the amount is less than 1% by weight, the properties of chitosan, particularly the antibacterial property and the water-absorbing and moisture-absorbing property, may not be sufficiently imparted to the fibrous cotton having the coating layer formed using the coating agent.

The organic solvent may be any one as long as the synthetic resin in the chitosan-containing synthetic resin can be dissolved.
Aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; chlorine solvents such as 1,1,1-trichloroethane and perchloroethane; and dimethylformamide. Examples include, but are not limited to: These solvents may be used alone or in combination of two or more.

In this coating agent, the synthetic resin emulsion is salted out with a chitosan acid aqueous solution to obtain a chitosan-containing synthetic resin in which chitosan is uniformly dispersed in the synthetic resin. By dissolving in the solvent, chitosan becomes a very fine particle and uniformly dispersed. In addition, since this coating agent is obtained by dissolving a synthetic resin separated from an aqueous solution by salting out in an organic solvent,
The water content is lower than that of the conventional water-soluble or emulsion-type coating agent, and therefore, when forming a coating layer on fiber cotton using this coating agent, it is possible to save heat energy in a drying process, Since the drying time can be shortened, the coating processing ability is excellent. For this reason, since it is not necessary to raise the drying temperature considerably in order to shorten the drying time unlike the conventional case, bumping of water is reduced, and a uniform coating layer can be formed. Further, since chitosan is used as an antibacterial agent, there is an advantage that there is no problem for the human body and safety is excellent.

Next, the coated fiber fabric of the present invention will be described. The coated cotton fabric of the present invention is obtained by coating the above-mentioned coating agent on the cotton fabric, drying and forming a coating layer. In the present invention, the fiber cotton may be any of a woven fabric, a knitted fabric, and a nonwoven fabric, and is not limited in its chemical composition. For example, cotton, polyester, rayon, nylon, acrylic fiber, and fibers of these fibers It may be a blended product, mixed weave, or mixed knit.

The above-mentioned coating agent is coated on the above-mentioned fiber cotton by a dry coating method such as a knife coater, knife over roll coater, blanket knife coater, inverted knife coater, direct roll coater, reverse roll coater, and the like. A gravure coater, a kiss coater, a bead coater and the like can be preferably used. When the above-mentioned coating agent is coated on fiber cotton, a cross-linking agent may be used in combination in order to impart solvent resistance and adhesiveness to the obtained coating layer.

[0016] In the case of this coated cotton fabric, by coating the cotton fabric with the above-mentioned coating agent, a uniform coating layer in which chitosan is uniformly dispersed is formed. Has the properties of, especially excellent antibacterial performance, moisture absorption and moisture permeability,
In addition, there is little variation in these properties and performance, and chitosan having a certain quality, especially antibacterial performance and water absorption performance, is obtained.

[0017]

The present invention will be specifically described below with reference to examples. Reference Example 1 A 2-liter, four-necked flask was charged with 600 g of ion-exchanged water and 1 g of sodium phosphate monobasic, deoxygenated with nitrogen gas, and heated to 50 ° C. with stirring.
Then, a pre-emulsion having the following composition and 202 g of an aqueous sodium hydrogen sulfate solution (sodium hydrogen sulfate / ion-exchanged water = 2/200) were added therein for 3 hours while maintaining the internal temperature of the flask at 49 to 51 ° C. Over a period of time, a polymerization reaction was performed, and an aging reaction was performed at the same temperature for 2 hours to obtain an acrylic emulsion.

[Pre-emulsion composition] butyl acrylate 400 g ethyl acrylate 130 g acrylonitrile 60 g 2-hydroxyethyl methacrylate 10 g dodecyl mercaptan 0.08 g emulgen 106 (trade name; emulsifier manufactured by Kao Corporation) 6 g emal 2F (trade name; Kao Corporation) Company-made emulsifier) 2.4 g potassium persulfate 2.4 g ion-exchanged water 200 g

Next, 50 g of an aqueous chitosan acid solution consisting of 30 g of chitosan, 30 g of acetic acid and 500 g of water was added to 1080 g of water.
g, the temperature was raised to 80 ° C, 360 g of the above acrylic emulsion was added dropwise with stirring, and the mixture was kept at 80 ° C for 1 hour, cooled to room temperature, and the precipitated acrylic resin was separated and neutralized. The resultant was thoroughly washed with water and dried to obtain 127.5 g of a brown chitosan-containing acrylic resin. Dissolve the dried chitosan-containing acrylic resin in toluene and add 15%
A toluene solution was prepared and used as the chitosan-containing acrylic resin solution of Reference Example 1. The chitosan-containing acrylic resin solution was a light brown, transparent liquid, and it was confirmed that chitosan was uniformly dispersed.

Reference Example 2 Aluminum sulfate hydrate 10
was dissolved in 1080 g of water, the solution was heated to 80 ° C., and 360 g of the acrylic emulsion obtained in the same manner as in Reference Example 1 was added dropwise with stirring for 15 minutes.
After cooling for 1 hour at room temperature, the precipitated acrylic resin was separated, washed sufficiently until it became neutral, and dried to obtain 126.5 g of a white acrylic resin. The dried acrylic resin was dissolved in toluene to prepare a 15% toluene solution, which was used as the acrylic resin solution of Reference Example 2. The acrylic resin solution was a colorless transparent liquid.

Reference Example 3 A 15% toluene solution was prepared by dissolving an acrylic resin in toluene, and 1 g of chitosan was dispersed in 1000 g of the 15% toluene solution to obtain a chitosan-containing acrylic resin solution of Reference Example 3. The solution of the chitosan-containing acrylic resin solution itself was a colorless and transparent liquid, but the chitosan was not dissolved at all and was in an unevenly dispersed state.

(Embodiment 1) Latitude 80D / 48f, Latitude 80D
A coating resin solution of the following composition is coated on a 210 taffeta woven fabric composed of / 48f nylon filament using a knife coater so that the thickness of the coating layer is uniform, dried at 120 ° C., and heat-set at 170 ° C. to perform coating. I got the cotton. The adhesion amount of the coating resin liquid was 1.8 g / m ² in dry weight. [Coating resin liquid] 100 parts of chitosan-containing acrylic resin solution of Reference Example 1 Paracuron CL-conc (trade name; crosslinking agent manufactured by Negami Kogyo Co., Ltd.) 3 parts Toluene 10 parts And the antibacterial performance of the obtained coated cotton was measured. As a result of measurement by the bacterial count method, the average was 3.2 and antimicrobial performance was recognized. In addition, it was found that there was almost no variation in the antibacterial performance depending on the test cloth, and the test cloth had antibacterial performance of a constant quality.

The antibacterial property was evaluated in the following manner according to the method of the Sanitary and Textile Processing Council of Japan (SEK). Test bacteria (Staphylococcus aureus, Staphylococcsu aureus IFO) were placed on two sterile test cloths weighing 0.2 g each.
13277) was added, and the viable cell count was measured after culturing at 37 ° C. for 18 hours in a closed container. The difference between the increase and decrease of the untreated cloth was determined by the following formula (I). . Increase / decrease value difference = log (B / A) −log (C / A) (I) (where A is the number of bacteria immediately after inoculation of the unprocessed sample, and B is culture for 18 hours in the unprocessed sample) And C is the number of bacteria after 18 hours of cultivation in the processed sample.) In the test, it is necessary to confirm the active state of the test bacteria.
If og (B / A)> 2, the test was considered valid, but if log (B / A) ≦ 2, the test was considered invalid and retested. The washing resistance is based on JIS
After washing 10 times according to the L0217-103 method,
The antibacterial performance was evaluated by the above method. When the difference in the number of bacteria after washing 10 times exceeded 1.6, it was determined that there was antibacterial activity.

(Example 2) Using a 75d / 76f polyester filament as a polyester filament,
A 5% aqueous solution of Asahi Guard AG-710 (trade name; water-repellent agent manufactured by Asahi Glass Co., Ltd.) is impregnated into a plain woven fabric composed of inches and 86 wefts / inch, squeezed with a mangle, dried,
It heat-set at 160 degreeC, and obtained the water-repellent cotton. next,
The chitosan-containing acrylic resin obtained in Reference Example 1 was coated using a knife with an acute-angled blade so that the thickness of the coating layer was uniform, dried at 120 ° C, and set at 160 ° C. The adhesion amount of the chitosan-containing acrylic resin was 2 g / m ² in terms of dry weight. When the antibacterial performance of the obtained coated cotton was measured in the same manner as in the above-mentioned method for measuring the number of bacteria, it was 4.6 on average, and antibacterial properties were recognized. In addition, it was found that there was almost no variation in the antibacterial performance depending on the test cloth, and the test cloth had antibacterial performance of a constant quality.

Comparative Example 1 A coated cotton was produced in the same manner as in Example 1 except that a coating resin solution having the following composition was used. When the antibacterial performance was measured in the same manner as in the above-mentioned bacterial cell count method, the average was 0.9, and no antibacterial activity was observed. [Coating resin solution] Acrylic resin solution of Reference Example 2 100 parts Paracron CL-conc (trade name; crosslinking agent manufactured by Negami Industry Co., Ltd.) 3 parts Toluene 10 parts

Comparative Example 2 A coated cotton was produced in the same manner as in Example 1 except that the chitosan-containing acrylic resin obtained in Reference Example 3 was used instead of the coating resin solution. When the antibacterial performance was measured in the same manner as in the above-mentioned bacterial count measurement method, it was 1.5, and no antibacterial activity was observed. Further, it was found that the antibacterial performance varied depending on the test cloth, and that the test cloth did not have a constant quality antibacterial performance.

[0027]

As described above, the coating agent according to the first aspect provides a chitosan-containing synthetic resin in which chitosan is uniformly dispersed in the synthetic resin by salting out the synthetic resin emulsion with an aqueous solution of chitosan acid. Furthermore, by dissolving the chitosan-containing synthetic resin in an organic solvent, chitosan is dispersed in a very fine particle state. In addition, since this coating agent is obtained by dissolving a synthetic resin separated from an aqueous solution by salting out in an organic solvent, the water content is lower than that of a conventional water-soluble or emulsion type coating agent. Therefore, when a coating layer is formed on fiber fabric using this coating agent, heat energy can be reduced in the drying step and the drying time can be shortened, so that the coating processing ability is excellent. For this reason, since it is not necessary to raise the drying temperature considerably in order to shorten the drying time unlike the conventional case, bumping of water is reduced, and a uniform coating layer can be formed. Also,
Since chitosan is used as an antibacterial agent, there is an advantage that there is no problem for the human body and safety is excellent.

Further, the coated cotton fabric according to claim 2 is coated on the fiber cotton with the coating agent according to claim 1 so that the coating is uniform and chitosan is uniformly dispersed. A layer is formed, thus the properties of chitosan, especially excellent antibacterial performance,
It has water-absorbing and moisture-permeable properties, and there is little variation in these properties and performance.
In particular, there is an advantage of having antibacterial performance and water absorption performance.

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Sumida 1-12 Wakamatsucho, Kanazawa City, Ishikawa Prefecture (56) References JP-A-7-133589 (JP, A) JP-A-3-51369 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) D06M 15/03

Claims (2)

(57) [Claims] 1. A coating agent obtained by dissolving a chitosan-containing synthetic resin obtained by salting out a synthetic resin emulsion with an aqueous solution of chitosan acid in an organic solvent. 2. A coated fiber fabric, wherein the coating agent according to claim 1 is coated on a fiber fabric and dried to form a coating layer.