JPH0425301B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antibacterial latex composition, and its purpose is to mold latex for medical devices, sanitary products, food manufacturing equipment, supplies, etc. that have sustained antibacterial activity. An object of the present invention is to provide an antibacterial latex composition suitable for manufacturing products.

Conventionally, various sterilizing disinfectants have been used in the medical, sanitary inspection, and food fields to prevent contamination and infection from various types of bacteria, actinobacteria, fungi, slime molds, viruses, and the like. Quaternary ammonium salt compounds, represented by benzalkonium chloride, are the most widely used antibacterial agents today because they have strong sterilizing power on a wide range of sanitary products and are also low in toxicity to the human body. It is one of the disinfectants used. Currently, these are usually provided as aqueous solutions, and the intended purpose can be achieved by immersing medical instruments in the aqueous solution or spraying the aqueous solution before use.

However, when medical instruments are used for a long period of time, we often experience in our daily lives that the effectiveness of antibacterial agents gradually decreases or disappears if only the initial disinfection is performed, and there is a strong desire to improve this situation.

The most effective countermeasure would be a system in which a constant amount of antibacterial agent at a minimum (growth) inhibitory concentration or higher is slowly released from the device during the use process. In order to realize such a system, it is necessary to obtain latex in which antibacterial agents are uniformly and stably dispersed.
Although it is necessary to mold this material into, for example, medical instruments, a latex in which a quaternary ammonium salt is uniformly and stably dispersed has not been obtained so far, as described below.

First, polymer latexes in which hydrophobic natural rubber or synthetic polymer compounds are dispersed in an aqueous medium are used for a variety of useful purposes today, but these latexes usually contain a substance that stabilizes the latex particles. Contains various surfactants and protective colloids to aid in floating and dispersion. For example, in natural rubber latex, protein, which is an ampholyte contained in its components, is adsorbed onto the surface of rubber particles, thereby acting as a kind of protective colloid and helping to stabilize the dispersion of latex particles. In addition, natural rubber latex tends to generate acid and coagulate due to the action of enzymes and bacteria contained in it, so to prevent this, 0.5 to 1.0% ammonium is usually added to keep the liquid alkaline. There is. Therefore, since the rubber particles are basically negatively charged, they are stably suspended and dispersed without agglomeration due to the mutual electrostatic repulsion between the particles. Also, anionic and/or nonionic surfactants are added to synthetic polymer latexes before or after polymerization, and cationic surfactants are used in practice unless there are special circumstances. There are very few examples. On the other hand, as can be seen from its chemical structure, quaternary ammonium salts as antibacterial agents belong to cationic disinfectants that have a positive charge and a hydrophobic group in one molecule. When added to rubber latex, the negative charge of latex particles is neutralized and destabilized, resulting in immediate irreversible gelation of the latex.
Adding grade ammonium salt-based antibacterial agents to Terrax was previously thought to be unreasonable, and no further serious consideration was given.

The present inventors have conducted intensive studies on antibacterial latex compositions suitable for manufacturing medical equipment, sanitary products, food manufacturing equipment, etc. made of terrax that have sustained antibacterial activity, and have surprisingly found that The inventors have discovered that even when a poorly water-soluble quaternary ammonium salt is added to the latex, a stable antibacterial latex composition can be obtained without causing gelation, and the present invention has been achieved.

That is, the present invention is an antibacterial latex composition comprising a natural rubber latex or a synthetic polymer latex and a poorly water-soluble quaternary ammonium salt.

The quaternary ammonium salt in the present invention is represented by the following structural formula ().

Here, R ¹ , R ² , R ³ and R ⁴ are an alkyl group, a benzyl group, a carboxyalkyl group, an alkyl group, or a benzyl group substituted with a nitro group or a chloro group,
hydroxyalkyl group, acetoxyalkyl group,
Alkylphenoxy group, alkoxysialkyl group, etc. Encyclopedia of Chemical
Technology, Vol. 19, pp. 521-531 (1982,
Wiley International Publication), Nishi, Imai,
"Surfactant Handbook" co-edited by Kasai, pp. 737-747 (1960
Journal of
American Chemical Society, Vol. 68, 753-759
(1946), R ¹ R ₂ , R ³ , R ₄ are benzyl groups, R ²
and a benzyldimethyldodecyl ammonium salt in which R ³ is a methyl group and R ⁴ is a dodecyl group, a benzyldimethyltetradecylammonium salt in which R ¹ is a benzyl group, R ² and R ³ are a methyl group, and R ⁴ is a tetradecyl group, R Benzyldimethylhexadecyl ammonium salt in which ¹ is a benzyl group, R ² and R ³ are a methyl group, and R ⁴ is a hexadecyl group, R ¹ , R ² and
Trimethyltetradecylammonium salt in which R ³ is a methyl group and R ⁴ is a tetradecyl group, and (2
-(2-p(1,1,3,3-tetramethylbutyl)phenoxy)ethoxy)ethyl benzethonium salt has strong bactericidal activity against a wide range of microorganisms and has low toxicity to the human body. , is the most widely used sterilizing agent in the medical, hygiene and food industries today, and is preferably used in the present invention. Among the above-mentioned quaternary ammonium salts, salts in which X is iodide, citrate, sulfate, phosphate, borate, etc. are poorly water-soluble.

In the present invention, poorly water-soluble means 100g at 20°C.
The solubility in distilled water is in the range of 0.001 to 3.0 g, preferably 0.005 to 2.0 g. If the solubility in water is less than 0.001 g, the efficacy as a bactericidal agent will be reduced, while if it exceeds 3.0 g, the latex will irreversibly gel when added to the latex, which is undesirable.

The content of poorly water-soluble quaternary ammonium salt in the antibacterial latex composition of the present invention is as follows:
Although it varies depending on the purpose, it is usually preferably 0.01 to 30wt based on the solid content of latex.
%, more preferably 0.1 to 10 wt%. If the content exceeds 30 wt%, the physical strength of the film of a molded product obtained from this latex composition tends to be poor, while if it is less than 0.01 wt%, it becomes difficult to exert its effectiveness as an antibacterial agent, so it is preferable. do not have.

The natural rubber latex used in the present invention is
The dispersion medium is an aqueous solution containing various organic and inorganic substances that flows out when the bark of a rubber plant is cut, and the rubber component is used as a dispersoid. Vulcanized latex containing softeners, fillers, anti-aging agents, colorants, etc. Synthetic polymer latexes include, for example, ethylene, styrene, vinyl acetate,
Homopolymers of vinyl monomers such as vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylic acid esters, vinylpyridine, methyl vinyl ether, or copolymers thereof, butadiene, isoprene, 1,3-pentadiene, 1,5-hexadiene , homopolymers of diene monomers such as 1,6-heptadiene and chloroprene, or copolymers thereof, copolymers of the above vinyl monomers and diene monomers, and other functional groups such as epoxide groups, amino groups, carboxyl groups, and acids. The main component is a copolymer of a vinyl monomer having an anhydride group, a hydroxyl group, an amide group, an N-methylolamide group, an isocyanate group, etc. and the above various monomers, and if necessary, a surfactant, a crosslinking agent, and a filler are added. Examples include those containing additives, softeners, etc.

The method for preparing the antibacterial latex composition of the present invention is not particularly limited as long as each component is mixed uniformly, and various known methods can be used. For example, the antibacterial agent may be mixed in a ball mill. Preferably, a method is employed in which a homogeneous paste-like aqueous dispersion is obtained by grinding with a grinder, and natural rubber latex or synthetic polymer latex is added thereto and mixed with stirring.

The antibacterial Relatex composition of the present invention is suitably used for molding medical instruments, sanitary instruments, food manufacturing equipment or equipment, etc., which have sustained antibacterial properties even during long-term use. Examples of specific molded products include various catheters including urinary catheters, bags such as urine collection bags, fluid supply and drainage tubes, sponges, rubberized cloth, paper sizing agents, nonwoven fabric binders, paints, Examples include adhesives. These are molded by a conventionally known dipping method, casting method, electrodeposition method, or the like. To give a more specific application example, the antibacterial latex composition of the present invention can be used for urinary catheters, which frequently cause urethritis, cystitis, pyelitis, etc. due to bacteria entering through the catheter when left in the body for a long period of time. The molded urinary catheter has the ability to release antibacterial agents in a sustained manner, and during its use, the antibacterial agent is continuously released through urine or drainage, which prevents urinary tract infections from various bacteria. It is extremely effective.

The present invention will be described in detail with reference to specific examples below.

Note that "parts" in the examples mean "parts by weight."

Example 1 0.3 parts of zinc dimethyldithiocarbamate, 1.5 parts of sulfur, 3 parts of zinc white, and 1.2 parts of stearic acid were added to 100 parts of a natural rubber latex solution (PH 10.7) with a solid content concentration of approximately 50 wt%, and the mixture was dispersed uniformly. A compounded latex containing natural rubber as the main component was obtained. When 10 parts of benzyldimethylhexadecyl ammonium iodide as an antibacterial agent was uniformly dispersed in 12 parts of distilled water into a paste form and added to this mixed latex while stirring, the latex did not aggregate and the antibacterial agent It was possible to obtain a latex composition in which the particles were uniformly dispersed. A film can be formed from the obtained composition,
About this film Bacillus subtilis
When an antibacterial activity test was conducted using ATCC6633 (medium NUTRIENTAGAR) as a test bacterium by the cylindrical plate method (disk method), an inhibition circle was produced, and this composition was confirmed to have antibacterial properties.

Comparative Example 1 When a 10 wt % aqueous solution of benzyldimethylhexadecyl ammonium chloride was added little by little to 100 parts of the same latex as used in Example 1 while stirring, the latex gradually became viscous and completely disappeared after approximately 3 ml was added. It turned into a gel.

Example 2 10 parts of benzethonium iodide dispersed in 12 parts of distilled water in paste form was added to 100 parts of the same latex as used in Example 1 with stirring, and the latex became uniform without agglomeration. dispersed into

When the obtained composition was subjected to the same test as in Example 1, the film showed antibacterial properties.

Example 3 10 parts of benzyldimethylhexadecyl ammonium phosphate was uniformly dispersed in 12 parts of distilled water in 100 parts of anionic styrene-butadiene copolymer latex (PH = 9.5) with a solid content concentration of approximately 50 wt%. When added while stirring,
The latex was uniformly dispersed without agglomeration.

When the obtained composition was subjected to the same test as in Example 1, the film showed antibacterial properties.

Claims (1)

[Scope of Claims] 1. An antibacterial latex composition comprising natural rubber latex or synthetic polymer latex and a poorly water-soluble quaternary ammonium salt. 2. The antibacterial latex composition according to claim 1, wherein the quaternary ammonium salt is trimethyltetradecylammonium salt. 3 Claim 1 in which the quaternary ammonium salt is benzyldimethyldodecyl ammonium salt
The antibacterial latex composition described in . 4. The antibacterial latex composition according to claim 1, wherein the quaternary ammonium salt is benzyldimethyltetradecylammonium salt. 5. The antibacterial latex composition according to claim 1, wherein the quaternary ammonium salt is benzyldimethylhexadecyl ammonium salt. 6. The antibacterial latex composition according to claim 1, wherein the quaternary ammonium salt is a benzethonium salt.