JPH0475933B2 - - 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., which have a positive 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. Among these, amphoteric antibacterial agents are one of the most widely used sterilizing disinfectants among the many antibacterial agents available today, as they have strong sterilizing power against a wide range of microorganisms and have low toxicity to the human body. It is. 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 fixed amount of antibacterial agent at a minimum (growth) inhibitory concentration or higher is released from the device during the course of its use. 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 an amphoteric antibacterial agent 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, 0.3 to 1.0% ammonia 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. Therefore,
Conventionally, when an amphoteric antibacterial agent is added to these latex solutions, the latex solution becomes colloidally unstable, and as a result, the latex particles sooner or later agglomerate or gel, resulting in an antibacterial latex composition with excellent long-term storage stability. I couldn't get anything.

The present inventors have developed an antibacterial latex composition suitable for manufacturing medical equipment, sanitary goods, food manufacturing equipment, etc. made of latex having sustained antibacterial activity, and in particular an antibacterial latex composition with excellent long-term storage stability. As a result of intensive research aimed at providing a composition, surprisingly, the desired purpose was achieved by blending cationic natural rubber latex or cationic synthetic polymer latex with a specific amphoteric antibacterial agent. This is what led to the discovery of the present invention.

That is, the present invention is an antibacterial latex composition comprising a cationic natural rubber latex or a cationic synthetic polymer latex and an amphoteric antibacterial agent represented by the following general formula ().

[In the formula, R ₁ is R(NHCH ₂ CH ₂ ) _o , R ₂ is
RNHCH ₂ CH ₂ or a hydrogen atom, R represents an alkyl group having 8 to 18 carbon atoms, and n is an integer of 1 to 3. ] The amphoteric antibacterial agent used in the present invention is alkylpolyaminoethylglycine hydrochloride represented by the above general formula (). When the number of carbon atoms in R in the general formula () is less than 8 or exceeds 18, or n
is 4 or more, it is not suitable because the antibacterial activity of the resulting composition is low. Preferred specific examples of the alkyl polyaminoethylglycine hydrochloride represented by the general formula () include dodecyl di(aminoethyl) in which R ₁ has 12 carbon atoms, n is 2, and R ₂ is H;
Glycine hydrochloride, R in R ₁ has 14 carbon atoms, n is 2,
Tetradecyl di(aminoethyl) where R ₂ is H
Glycine hydrochloride, R in R ₁ has 8 carbon atoms, n is 1,
Examples include di(octylaminoethyl)glycine hydrochloride in which R in R ₂ has 8 carbon atoms. In the present invention, amphoteric antibacterial agents can be used alone or in combination of two or more.

The content of the amphoteric antibacterial agent in the antibacterial latex composition of the present invention varies depending on the purpose, but is usually preferably 0.01 to 30 wt%, more preferably 0.1 to 30 wt%, based on the solid content of the latex.
It is 10wt%. If the content exceeds 30wt%, the physical strength of the film of the molded product obtained from this latex composition tends to be poor;
If it is less than that, it becomes difficult to exert its effectiveness as an antibacterial agent, which is not preferable.

Natural rubber latex is made by using an aqueous solution containing various organic and inorganic substances that flows out when cutting is made on the bark of a rubber plant as a dispersion medium, and using the rubber component as a dispersoid. It is a vulcanized latex containing vulcanization accelerators, softeners, fillers, anti-aging agents, colorants, etc. Ordinary latex contains ammonia as a PH regulator.
It is an anionic latex containing 0.3 to 1.0 wt% and having a pH adjusted to 9 to 11. On the other hand, the cationic natural rubber latex used in the present invention includes a so-called acidic latex whose pH is 4.7 or higher, and preferably 3 or lower, which is the isoelectric point of the protein that is the protective colloid. In this state, the rubber particles are stabilized by having a positive charge opposite to that of normal natural rubber latex and repelling each other. Such acidic latex is, for example, ordinary natural rubber latex (solid content concentration 50
~60%, PH=9~11), add a cationic surfactant or nonionic surfactant to about 1~5wt% based on the rubber content, and then add a suitable inorganic or organic acid. may be added to bring the pH to 4.7 or less, preferably 3 or less. Such acid latexes have rarely been used in the past, except as special cases in the treatment of negatively charged fibers and papers, or in the production of derivatives such as hydrochloric acid rubber, chlorinated rubber, or reduced rubber directly from the latex. First, there has been no known example of incorporating an amphoteric antibacterial agent as in the present invention.

Examples of cationic synthetic polymer latexes include ethylene, styrene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile,
(meth)acrylic acid ester, vinylpyridine,
Homopolymers of vinyl monomers such as methyl vinyl ether or copolymers thereof, homopolymers of diene monomers such as butadiene, isoprene, 1,3-pentadiene, 1,5-hexadiene, 1,6-heptadiene, chloroprene, etc. The copolymer, a copolymer of the above-mentioned vinyl monomer and diene monomer, and an epoxide group as a functional group,
The main component is a copolymer of a vinyl monomer having an amino group, a carboxyl group, an acid anhydride group, a hydroxyl group, an amide group, an N-methylolamide group, an isocyanate group, etc. and the above various monomers, and an emulsifying dispersant is added to the copolymer. Examples include those containing a cationic surfactant, and may also contain a nonionic surfactant, a crosslinking agent, a filler, a softener, etc., if necessary.

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, in the case of easily water-soluble disinfectants,
The aqueous solution can be directly added to the latex, or if the disinfectant is a solid that is poorly water-soluble, it can be ground in a ball mill to form a uniform paste-like aqueous dispersion. A method such as adding it to latex and stirring and mixing it is preferably employed.

The antibacterial latex composition of the present invention can be suitably used for molding medical instruments, sanitary instruments, food manufacturing equipment or fixtures, 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,
Examples include non-woven fabric binders, paints, adhesives, etc. 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 that invade through the catheter when left in the body for a long period of time. The urinary catheter molded in this way has the ability to release antibacterial agents in a sustained manner, and during its use, the antibacterial agents are continuously released in urine or body fluids.
It is extremely effective in preventing urinary tract infections from various bacteria.

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, 1.3 parts of sulfur, 2.8 parts of zinc white, and 1.2 parts of stearic acid were added to 100 parts of acidic natural rubber latex solution (PH2.5) with a solid content concentration of approximately 50 wt%, and uniformly dispersed. A compounded latex containing natural rubber as the main component was obtained. When 10 parts of a 20% aqueous solution of dodecyldi(aminoethyl)glycine hydrochloride as an antibacterial agent was added to this compounded latex, the latex did not aggregate and a latex composition in which the antibacterial agent was uniformly dispersed could be obtained. This latex composition remained stable without gelation even after being left for 3 months. A film can be formed from the obtained composition, and about this film, Bacillus
Subtilis ATCC 6633 (medium NUTRIENT
When an antibacterial activity test was conducted using the punch plate method using A.GAR) as a test bacterium, an inhibition zone was observed, indicating that this composition had antibacterial properties.

Comparative Example 1 When the same antibacterial agent used in Example 1 was added to an alkaline (PH9.8) natural rubber latex having the same composition as in Example 1, it immediately gelled.

Example 2 Tetradecyl di(aminoethyl) as a fungicide
When the same experiment as in Example 1 was conducted except that a 10% aqueous solution of glycine hydrochloride was used, a composition with good long-term storage stability for 3 months or more was obtained as in Example 1, and It was also confirmed that the formed film had antibacterial activity.

Example 3 Example 1 except that a 10% aqueous solution of di(octylaminoethyl)glycine hydrochloride was used as the antibacterial agent.
When the same experiment was conducted as in Example 1, 3
A composition with excellent long-term storage stability for more than a month was obtained, and it was also confirmed that a film formed from the composition had antibacterial properties.

Examples 4 and 5 Experiments were carried out in the same manner as in Example 4, except that octadecyldi(aminoethyl)glycine hydrochloride or dodecyltri(aminoethyl)glycine hydrochloride was used instead of di(octylaminoethyl)glycine hydrochloride. As a result, as in Example 4, a composition with excellent long-term storage stability of 3 months or more was obtained, and it was also confirmed that a film formed from the composition had antibacterial properties.

Claims (1)

[Scope of Claims] 1. An antibacterial latex composition comprising a cationic natural rubber latex or a cationic synthetic polymer latex and an amphoteric antibacterial agent represented by the following general formula (). [In the formula, R ₁ is R(NHCH ₂ CH ₂ ) _o , R ₂ is
RNHCH ₂ CH ₂ or a hydrogen atom, R represents an alkyl group having 8 to 18 carbon atoms, and n is an integer of 1 to 3. ] 2 Amphoteric antibacterial agents are dodecyl di(aminoethyl)glycine hydrochloride and tetradecyl di(aminoethyl)
Glycine hydrochloride or di(octylaminoethyl)
The composition according to claim 1, which is glycine hydrochloride.