JPS624063B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a sheet-like material having antibacterial properties, specifically a fiber-constituent sheet-like material to which a binder resin containing an antibacterial agent is attached (simply referred to as a "sheet-like material").
Concerning a new manufacturing method. Conventionally, various antibacterial sheet materials have been used to prevent contamination, discoloration, and decay caused by bacteria, fungi, yeast, etc., and these include polyurethane, SBR, NBR, other synthetic rubbers, and polyacrylic acid. It is made by mixing various antibacterial agents with a solvent-based, aqueous-based solution or dispersion of binder resin such as ester or nylon, applying the resulting treatment agent to a sheet, and coagulating and drying the resin liquid. ing. The type of binder resin is selected depending on the application, but all types are stable in the product state, so the antibacterial agent encapsulated in the binder resin does not easily ooze out to the surface. Therefore, the antibacterial agent is only effective when it appears on the surface of the binder resin, and its utilization rate is low.Furthermore, the antibacterial agent that appears on the surface easily disappears, so the antibacterial effect of a sheet-like material with antibacterial properties The drawback was that the durability was relatively short. The present invention provides a method for producing a sheet-like material having antibacterial properties that has a high utilization rate of antibacterial agents and excellent long-lasting antibacterial effects. The present invention provides a thermoplastic binder resin solution containing an antibacterial agent in an amount of 0.1 to 10% by weight based on the amount of the binder resin, and a liquid swelling agent encapsulated in a thermoplastic polymer shell in an amount of 1 to 100% by weight based on the amount of the binder resin. A treatment agent in which thermally expandable particles having a diameter of 1 to 100 microns is mixed with unexpanded particles or expanded particles is applied to a fiber-constituent sheet material and dried, and when the thermally expandable particles include unexpanded particles, , a method for producing a sheet-like article having antibacterial properties, characterized in that the binder resin is made porous by subjecting the particles to a heat treatment to expand them, either simultaneously with drying or separately. In the sheet material having antibacterial properties obtained by the production method of the present invention, the binder resin is made densely porous by the expanded thermally expandable particles mixed in the binder resin, and its surface area is significantly increased. At the same time, the bulk and flexibility increase, making it easier for the respiration action to exude the antibacterial agent sealed inside to the surface, making it extremely easy to use as a whole. It has the advantage of highly efficient use of antibacterial agents with significantly improved antibacterial properties and durability. In the present invention, the thermoplastic binder resin may be one having appropriate elasticity, strength, elongation, and adhesion to the shell of the thermally expandable particles, such as polyurethane, SBR, NBR, etc. , other synthetic rubbers, polyacrylic acid esters, nylon, and other resins are used, and the binder resin liquid includes solvent-based, aqueous-based solutions or dispersions of the above-mentioned resins that do not destroy the shells of the thermally expandable particles. is used. Antibacterial agents sterilize bacteria, mold, and yeast.
It is a drug that exhibits a growth-inhibiting effect, and examples of bacteria include Bacillus enterica, M. aeruginosa, Bacillus aeruginosa, Staphylococcus aureus, E. streptococcus, Bacillus subtilis, etc.; molds include Penicillium notaum, Black mold, Trichophyton, and Mentha. Examples of the yeast include Glophyllus and Trichophyton rubrum, and Candidauteilis. The antibacterial agent used in the present invention is required to be effective at low concentrations, and examples of such antibacterial agents include the following. 2-(4-thiazolyl)benzimidazole (commonly known as thiabendazole) is effective against Penicillium luteum and the like. N,N-dimethyl-
N′-(fluorodichloromethyl)thio-N′-phenylsulfanide. 2- as effective against Trichophyton mentaglophytes, Trichophyton rubrum, etc.
[3,5-dimethylpyrazolyl]-4-hydroxy-6-phenylpyrimidine. 1,1-hexamethylenebis[5-(P-chlorphenylbigand)] hydrochloride is effective against Aspergillus niger, Aspergillus flavus, etc. 2- as effective against Trichophyton mentaglophytes, Trichophyton rubrum, etc.
Naphthyl-N-methyl-N-(3-tolyl)
Thionocarbamate (also known as naphthiomate T). 2-(thioleanomethylsulfanyl)benzothiazole is effective against Aspergillus niger and the like. Trichlorcarbanilide is effective against Chaetomium and Crobosum. 3-trifluoromethyl-3',4'-dicyanocarbalide is effective against Aspergillus oryzae and the like. As effective against Trichoderma bilibi, etc.
2,4,5-tribromephenol. Organotin compounds effective against general molds, such as N-trichloromethylthio-4-cyclohexene-1,2-dicarboximide, triphenyltin chloride, and tribropyltin chloride. Antibiotics such as streptomycin, kasugamycin, haritamycin, and penicillin are effective against general Gram-positive and Gram-negative bacteria. When these antibacterial agents are crystalline, they are pulverized or dissolved in a solvent and mixed into a binder resin solution, and when they are liquid, such as tribrome phenol, they are adsorbed using silica gel or activated carbon. A good processing agent can be obtained by first adsorbing it onto a chemical substance to form a powder or granule, and then mixing it into a binder resin liquid. By using such adsorbent substances, the sustainability of the antibacterial performance of products using liquid antibacterial agents is greatly improved. The appropriate amount of the antibacterial agent used as described above is in the range of 0.1 to 10% by weight based on the amount of binder resin, and 0.1 to 10% by weight is appropriate.
If it is less than 10%, antibacterial properties will not be exhibited, and if it is more than 10%, problems will arise due to deterioration of the physical properties of the binder resin. The thermally expandable particles used in the present invention have a thermoplastic polymer shell such as vinylidene chloride-acrylonitrile-divinylbenzene copolymer, methyl methacrylate acrylonitrile-divinylbenzene copolymer, etc., and a shell of propane, butane, isobutane, pentane, hexane, etc. The average diameter of the thermally expandable particles is in the range of 1 to 100 microns, such as those shown in Japanese Patent Publication No. 42-26524, which contain a liquid expansion agent that vaporizes below the softening point of the polymer constituting the It is something. If the average diameter is smaller than this range, the coefficient of expansion of the thermally expandable particles will be low and the binder resin will not be porous enough to provide bulk and flexibility. When impregnating objects, it may not be uniformly impregnated, or the porous structure of the binder resin may become coarse and the surface smoothness of the product may be lost.
This may cause problems such as a decrease in the durability of antibacterial performance. The amount of thermally expandable particles added is suitably in the range of 1 to 100% by weight, most preferably in the range of 5 to 50% by weight, based on the amount of binder resin. If the amount added is less than 1%, the porosity will be insufficient and the object of the present invention cannot be achieved, and if it is more than 100%, the expansion coefficient of the binder resin will be excessive, and as a result, the physical properties of the sheet material will be impaired. This is not desirable. The thermally expandable particles are dispersed and mixed in the binder resin liquid while remaining unexpanded or after being expanded in advance. As mentioned above, a binder resin liquid mixed with an antibacterial agent and unexpanded or expanded particles of thermally expandable particles is applied as a treatment agent to a sheet-like object, and this sheet-like object is coated with natural fibers, rayon, acetate, etc. Non-woven fabrics, woven and knitted fabrics, etc. made of synthetic fibers such as man-made fibers, polyester, and nylon are used.For applications that particularly require elasticity, woven fabrics made using fibers and threads that have been given crimped extensibility are used. In the case of knitted fabrics or nonwoven fabrics, it is preferable to use stretchable fabrics in which fibers are adhesively bonded in a dotted network structure. In order to apply a treatment agent to such a sheet-like material, methods used for ordinary resin treatment such as a dipping method, a spray method, a knife roll coating method, etc. can be used. After applying the treatment agent to the sheet-like material, it is dried. When the treatment agent contains unexpanded thermally expandable particles, a heat treatment is performed to expand the unexpanded particles simultaneously with or separately from the drying. The treatment agent is a mixture of thermally expandable particles, and it is preferable to perform the heat treatment to expand the particles at the same time as drying from the viewpoint of simplifying the process, but the antibacterial agent is easily affected by heating. In such a case, it is meaningful to use a processing agent mixed with expanded particles that have been expanded in advance.The present invention is not limited to the above, and the present invention is not limited to the above, but it is possible to use a processing agent mixed with unexpanded thermally expandable particles in the form of a sheet. The particles may be expanded by heating before being applied to an object. In the sheet-like product obtained as described above, the adhered binder resin becomes porous due to the presence of the expanded particles, and the pore structure forms a substantially continuous structure. It is preferable that a sheet material to which a binder resin containing expanded particles is attached is subjected to a compression treatment or a solvent application treatment to destroy the expanded particles, and by performing such treatment, a high level of sustained antibacterial performance can be achieved. Demonstrated. It is preferable to carry out the compression treatment for destroying the expanded particles at the same time as the heating treatment for expanding the thermally expandable particles, from the viewpoint of process simplicity and thermal economy. In addition, as another means to ensure the formation of a communicating structure, it is also effective to apply a treatment agent to the sheet-like material and, before drying, perform a binder resin gelation treatment such as a salt bath or far-infrared irradiation. When such means are used, the level of antibacterial performance is even higher, even if the persistence is somewhat shortened. In addition, in the present invention, the treatment agent includes pigments, dyes, plasticizers, antioxidants, in addition to antibacterial agents and thermally expandable particles.
Of course, additives such as ultraviolet absorbers may be added depending on the application. The present invention will be explained below based on examples. In the examples, all percentages and percentages are by weight unless otherwise specified. Example 1 Using SBR latex (Luxstar TR8255A manufactured by Dainippon Ink and Chemicals) as a binder resin, a binder resin solution containing an antifungal agent and having a gel point adjusted to 45° C. was prepared according to the following composition. SBR latex (concentration 50%) 100 parts Pluconik L-61 (manufactured by Asahi Denka Kogyo) 2 parts Water 15 parts Naphthiomate: antifungal agent 4 parts Scoreol 400 (manufactured by Kao Atlas) 0.4 parts NH ₄ C 10% aqueous solution 30 parts Zno 50 % aqueous dispersion 4 parts This binder resin liquid was made of vinylidene chloride-acrylonitrile-divinylbenzene copolymer (weight ratio 70:30:0.3) with a softening point of about 80°C, with isobutane encapsulating about 15% of the shell weight in the shell. Average diameter is 15
micron thermally expandable particles (containing 30% water),
Test 1 for each 100 parts of SBR latex
0 parts for test 2, 5 parts for test 3, 10 parts for test 4, and 15 parts for test 4 were added and mixed to prepare a processing agent. Apply those processing agents to a thickness of 1.3 mm and a basis weight of 0.25.
g/cm ² of polyester fiber, the solid content is in the range of 100 to 103% of the weight of the nonwoven fabric by impregnation and squeezing method, and after gelling treatment with far infrared irradiation. , and heated at 120°C for 15 minutes. After lightly washing each nonwoven fabric product with water and drying it,
As a result of testing using Trichophyton mentagrophytes according to the agar plate method of the AATCC method, the thermally expandable particle-added product showed excellent antibacterial properties and durability as shown in Table 1.

[Table] Example 2 Using the same thermally expandable particles as in Example 1, the following mixture was made and used as a treatment agent. Polyurethane resin emulsion (product name: Bontaiku 1050 NS, manufactured by Dainippon Ink and Chemicals)
(concentration 20%) 200 parts thermally expandable particles (contains 30% water) 30 parts Hibitene (antibacterial agent) 1 part
It was applied to a 0.7 mm stretchable knitted fabric using the impregnating and squeezing method to give a solid content of 100 g/m ² , and after pre-drying at 60°C,
Heat compression was performed for 2 minutes at 120° C. and a pressure of 0.05 Kg/cm ² using a cylinder press machine. On the other hand, as a comparative sample, a sample was prepared under the same conditions as above using the same Recipe treatment agent as above except that no thermally expandable particles were added. When the cross section of the above-mentioned sheet-like material obtained using a treatment agent containing thermally expandable particles was observed using an electron microscope, the average diameter of the particles was expanded to 52 microns, and it was confirmed that communicating pores were formed. It was done. This sheet-like material has a thickness of 1.2 mm, a moisture permeability of 13.2 mgH ₂ O/cm ² hr,
The expansion/contraction rate was 60%. Here, the expansion/contraction rate is JIS-L-
1018A, a test piece with a width of 2.5 cm and a gauge gap of 50 mm is stretched by 50% at a speed of 200 mm/min and recovered at the same speed after 3 minutes. The recovery rate is calculated using the following formula. Rate= _25-1 /25×100%. However, ₁ is the elongated permanent strain length (mm) in the test when the load becomes 0. Bacterial inhibition diameters were measured for this sheet and comparative samples in order to examine their antibacterial performance.
The measurement was based on inoculating a sheet cut out to a diameter of 8 mm and a comparison sample into a bacterial culture medium with the following composition, and culturing at 35 to 37°C for 48 hours to determine bacterial inhibition. Medium composition: Beef extract 3g Peptone 10g Salt 5g Water 1000c.c. PH 7.2 The results are shown in Table 2.

[Table] Example 3 A treatment was carried out under the same conditions as in Example 2, using a treatment agent in which 1 part of thiabendazole was added instead of Hibitene in the treatment agent in Example 2, and a treatment agent in which thermally expandable particles were removed. A main sample and a comparative sample were prepared and their antibacterial properties were compared. For antibacterial properties, dispense the following bacterial culture medium into a shear dish, cut out each sample to a diameter of 8 mm, place each sample in the center of the shear dish, and heat at 30℃±2.
This was done by measuring the bacterial inhibition diameter after culturing for one week under conditions of 95±5% RH and 95°C. Medium composition: Glucose 40g Peptone 10g Agar 20g Water 1000c.c. PH 5.5-6.5 The results are shown in Table 3.

【table】

Claims (1)

[Claims] 1 In a thermoplastic binder resin liquid, 0.1 to 10% by weight of an antibacterial agent based on the amount of the binder resin, and 1 to
A treatment agent mixed with unexpanded particles or expanded particles of thermally expandable particles with an average diameter of 1 to 100 microns containing a liquid expansion agent in a 100% thermoplastic polymer shell is applied to the fiber-containing sheet material. and drying, and when the processing agent contains unexpanded thermally expandable particles, the binder resin is made porous by performing a heat treatment to expand the particles simultaneously with drying or separately. A method for producing a sheet material with antibacterial properties.