Among the conventional antibacterial compounds, those of low molecular weight are used as merely mixed with materials (such as resins) for forming various products, so that the antibacterial compound inevitably dissolves out, consequently becoming impaired in antibacterial activity and causing environmental pollution. Also encountered are problems such as toxicity of the compound to the living body due to contact with the product, and appearance of resistant bacteria.
To solve these problems, antibacterial polymers have been developed in recent years which are prepared by introducing an antibacterial functional group into high-molecular-weight compounds. These antibacterial polymers include, for example, those comprising a repeating unit represented by the general formula (3) (JP-A-100254/1986) and those comprising a repeating unit represented by the general formula (4) (JP-A-246205/1986). ##STR2## wherein R.sup.10 is methyl or ethyl, R.sup.11 is alkyl having 3 to 30 carbon atoms. ##STR3## wherein the groups R.sup.12 are the same or different and are each alkyl having 1 to 4 carbon atoms, R.sup.13 is alkyl having 14 to 20 carbon atoms, and X.sup.- is an anion.
However, these known antibacterial polymers are not fully satisfactory in antibacterial activity.
The antibacterial polymer is prepared by reacting a tertiary amine with a polymer having a reactive chlorine group in its side chain to substitute the tertiary amine for the reactive chlorine group, whereas difficulty is encountered in completely effecting the substitution, consequently permitting many active chlorine-containing functional groups to remain in the molecule. Accordingly, the antibacterial polymer itself problems in respect of stability and safety to the human body.
To overcome these problems, antibacterial polymers are also prepared by synthesizing an antibacterial polymerizable monomer and copolymerizing the monomer with other monomer. For example, antisoiling coating compositions are known which comprise as an effective component a copolymer containing a monomer represented by the general formula (5) (JP-A-64167/1990). ##STR4## wherein R.sup.14 is a straight-chain or branched alkyl or alkenyl having 8 to 22 carbon atoms, R.sup.15 and R.sup.16 are each alkyl having 1 to 3 carbon atoms, R.sup.17 is a hydrogen atom or methyl, B is O--CO or O--CH.sub.2, and X is a monovalent anion.
Further according to a report of Senuma et al., polymers are prepared by reacting chloromethylstyrene with cetyldimethylamine [C.sub.16 H.sub.33 N(CH.sub.3).sub.2 ] to obtain a quaternary ammonium salt polymer represented by the general formula (6), and copolymerizing the monomer with acrylonitrile [High-Polymer Fiber Material Research Institute, Research Report, No. 159 (1988) , pp. 17.about.22]. However, these polymers still remain to be improved in antibacterial activity. ##STR5##
Further U.S. Pat. No. 4,009,201 discloses that a polymer is produced by preparing a cationic monomer represented, for example, by the formula (7) and polymerizing the monomer, but merely states that the polymer is for use as an absorber or is useful for giving improved antistatic or pigment accepting effects, and says nothing whatever about antibacterial applications. Additionally, the monomer, wherein a polymerizable vinyl group is linked to a functional group having a cationic group by arm ester group, is susceptible to hydrolysis, so that the polymer derived from the cationic monomer has the problem that the side chain containing the cationic group (diammonium group) dissolves out as released from the polymer main chain to impair the function of the polymer. ##STR6##
Among these researches, we have already found the compounds disclosed in U.S. Pat. No. 4,826,924 and the compounds disclosed in JP-A-342504/1992 as compounds which are especially excellent in antibacterial activity. These compounds are prepared conventionally by reacting a tertiary amine with a polymer having a reactive chlorine group on the side chain and substituting the tertiary amine for the reactive chlorine group, whereas it is difficult to completely effect the substitution of the tertiary amine or like compound having a great molecular weight. The reaction therefore requires a prolonged period of time or involves the likelihood that the chlorine group will remain unreacted in the molecule to impair the safety and stability of the polymer.
Accordingly, we have conducted continued research to ensure higher safety and, at the same time, to simplify the reaction process. In the course of the research, an attempt was made, for example, to substitute a third component, such as an alkyl ammonium salt, which is lower in molecular weight and easy to substitute, for the unreacted chlorine group, and a corresponding result was achieved. To obtain the desired composition with greater ease, the result was nevertheless still unsatisfactory from the viewpoint of simplifying the reaction process and the stability of the polymer in respect of quaternization and polydispersity.
Further in the case of compounds (2) wherein A is phenylene which may have a substituent, a problem arises when the compound is present in a medium, such as water or alcohol, which has nucleophilic reactivity. Since the benzyl group is highly reactive, the compound is likely to decompose in the solvent, permitting the amine-containing side chain to become released or becoming degraded or insoluble while being stored for a long period. Furthermore, since the compound is not always fully amenable to adsorption to a wide variety of carriers, articles for example of acrylic, urethane or like sheet or fibers having the compound applied thereto fail to semipermanently retain an antibacterial effect. To solve this problem, we have devoted efforts to the preparation and screening of peripheral substances and found substances having high safety for use in such a field.
An object of the present invention is to provide a polymerizable monomer for readily giving an antibacterial polymer which is excellent in bactericidal activity, high in safety and stability and capable of retaining its effect for a prolonged period of time even in a reactive environment, and to provide the polymer and a process for preparing the same.
The present invention provides a polymerizable monomer represented by the general formula (1) ##STR7## wherein R.sup.1 is a hydrogen atom, methyl, chlorine or cyano, R.sup.2 is alkylene having 1 to 4 carbon atoms, R.sup.3 is alkylene having 3 to 10 carbon atoms, R.sup.1 is alkyl having 6 to 18 carbon atoms, R.sup.5 to R.sup.8 are the same or different and are each alkyl or substituted alkyl having 1 to 3 carbon atoms, A is methylene, phenylene, substituted phenylene, --CH.sub.2 O--, --CH.sub.2 CH.sub.2 O--, --CO--, --CO--N(R.sup.9)-- (wherein R.sup.9 is a hydrogen atom or methyl) or vinylene, m is 0 or 1, arid X and Y are the same or different, and are each a monovalent anion or form a bivalent anion when taken together.
The present invention further provides a polymer which has a structural unit derived from noncrosslinkable or crosslinkable vinyl monomer or from a mixture of such monomers, and a structural unit represented by the general formula (2) ##STR8## wherein R.sup.1 is a hydrogen atom, methyl, chlorine or cyano, R.sup.2 is alkylene having 1 to 4 carbon atoms, R.sup.3 is alkylene having 3 to 10 carbon atoms, R.sup.4 is alkyl having 6 to 18 carbon atoms, R.sup.5 to R.sup.8 are the same or different and are each alkyl or substituted alkyl having 1 to 3 carbon atoms, A' is methylene, --CH.sub.2 O--, --CH.sub.2 CH.sub.2 O--, --CO--, --CO--N(R.sup.9)-- (wherein R.sup.9 is a hydrogen atom or methyl) or vinylene, m is 0 or 1, and X and Y are the same or different, and are each a monovalent anion or form a bivalent anion when taken together.
The present invention further provides a process for preparing a polymer characterized by polymerizing a noncrosslinkable or crosslinkable vinyl monomer or a mixture of such monomers with a monomer represented by the general formula (1).
The present invention further provides a disinfectant composition comprising the polymer for destroying bacteria which are resistant to antibiotics.
The present invention further provides a method of imparting antibacterial properties to fibers by applying the polymer to the fibers.
In the compound represented by the general formula (1), especially preferable as the alkylene group represented by R.sup.3 is a group having 4 to 6 carbon atoms from the viewpoint of antibacterial properties. Further preferable as the alkyl group represented by R.sup.4 is a group having 10 to 14 carbon atoms from the viewpoint of antibacterial properties because it is thought that the hydrophobicity of the functional group and the electron density of quaternary ammonium on the functional group have a close relation with antibacterial properties.
With reference to the general formula (1), examples of substituents on the substituted phenylene represented by A are halogen atom such as fluorine, chlorine, bromine and iodine, lower alkyl such as methyl, ethyl, propyl and butyl, lower alkoxyl such as methoxy, ethoxy, propoxy and butoxy. Although the anions represented by X and Y are not limited specifically insofar as they are capable of neutralizing positive charges, examples of useful anions are monovalent anion such as chlorine ion, bromine ion, iodine ion, nitrate on, perchloration, acetate ion, methylsulfate ion, benzenesulfonate ion, chlorobenzenesulfonate ion and toluene sulfonate ion, bivalent anion such as sulfate ion and methyl phosphate ion.
Among the compounds of the general formula (1), the compound (1a) wherein the group represented by A is methylene, phenylene, substituted phenylene, --CO--, --CO--N(R.sup.9)-- (wherein R.sup.9 is as defined above) or vinylene can be prepared, for example, by reacting a compound represented by the general formula (8) with a compound represented by the general formula (9). ##STR9## wherein R.sup.3 to R.sup.8 and X are as defined above. ##STR10## wherein R.sup.1, R.sup.2, m and Y are as defined above, A.sup.1 is methylene, --CO--, --CO--N(R.sup.9)--, (wherein R.sup.9 is as defined above) or vinylene.
The reaction is conducted usually in a solvent, with heating if required. The solvent is not limited specifically insofar as it does not influence the reaction. Examples of useful solvents are methanol, ethanol, propanol and like alcohols, dimethyl ether, tetrahydrofuran and like ethers, benzene, toluene and like aromatic hydrocarbons, dichloromethane, carbon tetrachloride and like halogensted hydrocarbons, acetone, ethyl acetate, dimethyl sulfoxide and dimethylformamide. Since the desired product (2a) and the compound (9) are both polymerizable, the reaction may be conducted with a usual polymerization inhibitor, such as hydroquinone or catechol, added to the reaction system when so required. The mixing ratio of the compound (9) to the compound (8) is not limited specifically but can be determined suitably from a wide range. The compound is used usually in an amount of about 0.7 to about 0.2 moles, preferably about 0.9 to about 1.0 mole, per mole of the compound (8).
The mono quaternary ammonium salt derivative of the general formula (8) is prepared, for example, by reacting an alkanediamine derivative substituted with lower alkyl and represented by the general formula (10) with a compound represented by the general formula (11) in a solvent or in the absence of solvent, with application of heat when required. ##STR11## wherein R.sup.3 and R.sup.5 to R.sup.8 are as defined above. EQU R.sup.4 X (11)
wherein R.sup.4 is as defined above.
The solvent is not limited specifically insofar as it produces no influence on the reaction. Examples of useful solvents are methanol, ethanol and like lower alcohols, acetonitrile and like nitriles, and tetrahydrofuran and like ethers. Although the mixing ratio of the compound (10) to the compound (11) is not limited specifically, usually about 1.0 to about 5 moles, preferably about 1.2 to about 4 moles, of the compound (10) is used per mole of the compound (11).
Examples of useful compounds (10) are N,N,N',N'-tetramethyl-1,3-propanediamine, N,N,N',N'-tetramethyl-1,4-butanediamine, N,N,N',N'-tetramethyl-1,5-pentanediamine, N,N,N',N'-tetramethyl-1,6-hexanediamine, N,N,N',N'-tetramethyloctanediamine, N,N,N',N'-tetramethyldecanediamine, N,N,N',N'-tetraethylethylenediamine, N,N,N',N'-tetraethyl-1,3-propanediamine, N,N,N',N'-tetraethyl-1,4-butanediamine, N,N,N',N'-tetraethyl-1,5-pentanediamine and N,N,N',N'-tetraethyl-1,6-hexanediamine. Examples of useful compounds (11) are those having about 6 to about 18 carbon atoms, such as alkyl chloride, alkyl bromide, alkyl iodide, alkyl benzenesulfonate, alkyl chlorobenzenesulfonate and alkyl toluenesulfonate.
Examples of useful compounds (9) are alkyl halides or methallyl halides wherein the halogen atom is chlorine, bromine or iodine, allyl benzenesulfonate, allyl chlorbenzenesulfonate, allyl toluenesulfonate, chloromethylstyrene, chloromethyl vinyl ketone, bromomethyl vinyl ketone, methallyl benzenesulfonate, methallyl chlorobenzenesulfonate, methallyl toluenesulfonate, .alpha.-methyl (chloromethyl) styrene, .alpha.-chloro (chloromethyl) styrene, .alpha.-cyano (chloromethyl) styrene, .alpha.-chloromethylacrylonitrile, N-2-chloroethylacrylamide, N-2-bromoethylacrylamide, N-methyl-N-2-bromoethylacrylamide, N-2-bromoethylmethacrylamide, N-methyl-N-2-bromoethylmethacrylamide, N-2-tosyloxyethylacrylamide and N-methyl-N-2-tosyloxyethylmethacrylamide.
The compound (1b) of the formula (1) wherein the group represented by A is --CH.sub.2 O-- or --CH.sub.2 CH.sub.2 O-- can be prepared, for example, by reacting a compound represented by the general formula (12) with a compound represented by the general formula (13). ##STR12## wherein R.sup.2 to R.sup.8, X and Y are as defined above. ##STR13## wherein R.sup.1 is as defined above, A.sup.2 is methylene or ethylene, Z is a halogen atom, lower alkoxyl having 1 to 4 carbon atoms, lower acyloxy having 2 to 5 carbon atoms, benzenesulfonyloxy, chlorobenzenesulfonyloxy, tosyloxy or methanesulfonyloxy. Examples of lower acyloxy groups are acetyloxy, propionyloxy, butyryloxy and valeryloxy.
The reaction is carried out usually in a solvent in the presence of a base, with application of heat when required. The solvent is not limited specifically insofar as it produces no influence on the reaction. Examples of useful solvent are ether, tetrahydrofuran, dichloromethane, chloroform, dimethylformamide, dimethyl sulfoxide, etc. Since the desired product (2b) and the compound (13) are both polymerizable, the reaction may be carried out with hydroquinone, catechol or like usual polymerization inhibitor added to the reaction system when so required. The base is used usually in an approximately stoichiometric amount although the amount is not limited specifically. While the mixing ratio of the compound (12) to the compound (13) is not limited specifically, usually about 0.7 to about 1.2 moles, preferably about 0.9 to about 1.0 mole, of the compound (12) is used per mole of the compound (13).
The base to be used is not limited specifically but can be a usual one. Examples of useful bases include inorganic bases such as sodium hydroxide, potassium hydroxide and sodium carbonate, and organic bases such as pyridine, piperidine, diisopropylamine, triethylamine and diazabicyclooctane.
Examples of useful compounds (13) are allyl halides or methallyl halides wherein the halogen atom is chlorine, bromine or iodine, 4-bromo-1-butene, 3-butenyl toluenesulfonate, esters of benzenesulfonic acid, toluenesulfonic acid or chlorobenzenesulfonic acid with allyl alcohol or methallyl alcohol, and 2,3-dichloropropene.
The compound (12), which is a known substance, can be prepared, for example, by reacting a compound (8) with a compound represented by the general formula (14). EQU HO--R.sup.2 Y (14)
wherein R.sup.2 and Y are as defined above.
The reaction is conducted usually in a solvent which will not exert any influence on the reaction while heating the reaction system when so required. Although the mixing ratio of the compound (14) to the compound (8) is not limited specifically, usually about 1.0 to about 3 moles, preferably about 7.2 to about 2 moles, of the compound (14) is used per mole of the compound (8). Examples of useful compounds (14) are 2-halogeno-1-ethanol, 3-halogeno-1-propanol, 4-halogeno-1-butanol, 3-halogeno-2-methyl-1-propanol (wherein halogen atom is chlorine, bromine, iodine atom, etc.), 2-hydroxyethyl benzenesulfonate, 2-hydroxyethyl toluenesulfonate, 3-hydroxypropyl toluenesulfonate and 4-hydroxybutyl toluenesulfonate.
The compound (12) can also be produced, for example, by the process comprising protecting the hydroxyl group of the compound (14) with a suitable functional group W to obtain a compound represented by the general formula (14a), reacting this compound with the compound (8) to prepare a compound represented by the general formula (12a) and hydrolyzing the resulting compound. The functional group represented by W is, for example, acetyl, tetrahydropyranyl, methoxymethyl, benzenesulfonyl, toluenesulfonyl or the like. EQU WO--R.sup.2 Y (14a)
wherein R.sup.2 and Y is as defined above, and W is the functional group. ##STR14## wherein R.sup.2 to R.sup.8, X, Y and W are as defined above.
The reaction between the compound (8) and the compound (14a) is carried out in a suitable solvent, with application of heat when so required. The solvent is not limited particularly insofar as it exerts no influence on the reaction. For example, the same solvent as is used for preparing the compound (8) is usable. The amount of the compound (14a) to be used is not limited specifically but can be determined suitably from a wide range. It is usually about 1.0 to about 3 moles, preferably about 1.2 to about 2 moles, per mole of the compound (8). Examples of compounds (14a) are 2-halogenoethyl acetate, 2-halogenoethyl tetrahydropyranyl ether, 4-halogenobutyl toluenesulfonate (wherein halogen atom is chlorine, bromine, iodine atom, etc.), ethylene glycol blsbenzenesulfonate and ethylene glycol bistoluenesulfonate.
The compound (12a) is hydrolyzed by a usual method. The compound (12a) can be readily converted to the compound (12), for example, by treating the compound in dilute hydrochloric acid, with heating when necessary.
The compounds (1) and intermediates thereof obtained by the foregoing reactions can be isolated and purified by usual methods such as filtration, extraction, concentration and recrystallization.
The copolymer of the present invention can be produced by subjecting a noncrosslinkable or crosslinkable vinyl monomer or a mixture of such monomers, and the compound (1) to a usual polymerization process such as solution polymerization, solid-phase polymerization, bulk polymerization, emulsion polymerization or suspension polymerization. Among these processes, it is desirable to use the solution polymerization process. The type of solvent to be used for the process is not limited particularly insofar as the solvent produces no adverse effect on the reaction. Examples of solvents usable are protonic solvent such as water, methanol, ethanol and propanol, ether solvent such as ether, tetrahydrofuran and dioxane, halogenated hydrocarbon such as chloroform and carbon tetrachloride, aromatic hydrocarbon such as benzene and toluene, nitrile solvent such as acetonitrile and propionitrile, aprotic polar solvent such as dimethylformamide, dimethyl acetamide, hexamethylphosphoric triamide and dimethyl sulfoxide.
Examples of useful noncrosslinkable vinyl monomers are styrene, p-methylstyrene, p-bromostyrene, p-chlorostyrene, .alpha.-chlorostyrene, .alpha.-bromostyrene or like polymerizable aromatic compound; acrylic acid, methyl acrylate, ethyl acrylate, lauryl acrylate, methyl .alpha.-chloroacrylate, 2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, lauryl methacrylate or like polymerizable carboxylic acid ester and salt thereof; vinyl acetate, vinyl trifluoroacetate, vinyl butyrate, vinyl benzoate or like vinyl ester monomer; vinyl chloride, vinyl fluoride, vinylidene chloride, vinylidene fluoride or like halogenated vinyl monomer; isobutyl vinyl ether, n-butyl vinyl ether or like vinyl ether monomer; acrylamide, N-methyl acrylamide, N-ethyl acrylamide, N-methyl methacrylamide, N-ethyl methacrylamide or like polymerizable amide; acrylonitrile, methacrylonitrile, .alpha.-chloroacrylonitrile, vinylidene cyanide or like polymerizable nitrile; ehtylene, propylene, isobutylene, pentene, hexene, cyclohexene, norbornene, allene, butadiene, isoprene, chloroprene or like olefinic monomer; alkyl vinyl sulfide or like vinyl sulfide monomer; N-vinylcarbazole, 4-vinylpyridine, N-vinylpyrrolidone or like nitrogen-containing heterocyclic monomer; methyl vinyl ketone, phenyl vinyl ketone or like vinyl ketone monomer; maleic acid, maleic anhydride, acrolein, acrylic acid chloride, vinyl isocyanate, vinyl silane, allyl silane, polymerizable monomer represented by the formula (1).
Examples of useful crosslinkable vinyl monomers are divinylbenzene, divinylnaphthalene and the like. These monomers are usable singly, or at least two of them can be used in mixture.
The charge molar ratio of the compound of the formula (1) of the invention to the monomer to be copolymerized therewith is usually about 0.001.about.99.0: 99.999.about.1.0, preferably about 1.about.50: 99.about.50.
The polymerization reaction can be conducted efficiently usually in the presence of a polymerization initiator. Examples of useful polymerization initiators are azo initiator such as 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis-1-cyclohexanecarbonitrile and dimethyl-2,2'-azobisisobutyrate, peroxide such as hydrogen peroxide, benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, ammonium persulfate and potassium persulfate, redox initiater such as a combination of hydrogen peroxide or ammonium persulfate and sodium sulfite or ferrous ion, organic metal compound such as phenylmagnesium bromide and butyl lithium. The amount of the initiator to be used, which differs with the kind thereof, mode of polymerization and desired molecular weight of the copolymer, is usually 1.times.10.sup.-5 .about.0.5 mole/l, preferably 1.times.10.sup.-4 .about.5.times.10.sup.-2 mole/l.
In the case where the solution polymerization process is employed, the solvent to be used is not limited specifically insofar as it exerts no adverse influence on the reaction. Examples of useful solvents are protonic solvent such as water, methanol, ethanol, propanol, methyl cellosolve and ethyl cellosolve, ether solvent such as ether, tetrahydroluran, dioxane, dimethoxyethane and diglyme, halogenated hydrocarbon such as dichloromethane, chloroform and carbon tetrachloride, aromatic hydrocarbon such as benzene, toluene and xylene, nitrile solvent such as acetonitrile and propionitrile, aprotic polar solvent such as dimethylformamide, dimethyl acetamide, hexamethylphosphoric triamide and dimethyl sulfoxide. At least two of these solvents are usable in mixture.
The reaction temperature and the reaction time, although varying with the reactivity of the monomer and the type of solvent used, are determined preferably from the respective ranges usually of 0.degree. to 100.degree. C. and 3 to 120 hours.
The copolymer can be isolated and purified by a usual method of after treatment. For example, the reaction mixture is added to an excessive amount of solvent in which the product is sparingly soluble to separate out the product, which is then separated off as by filtration. When the product needs to be further purified, reprecipitation or like conventional method is resorted to.
It is desired that the copolymer of the present invention be 1,000 to 2,000,000, preferably 5,000 to 300,000, in number average molecular weight Mn and 1.1 to 2.0 in Mw/Mn (Mw: weight average molecular weight). Since the polymerization degree is governed by factors such as the concentration of charges for the polymeriazation reaction, kind and concentration of the initiator, reaction temperature and reaction time, a copolymer having the desired molecular weight and polydispersity can be obtained by determining these factors in accordance with the situation concerned.
The copolymer obtained is subjected to ion exchange by a known procedure to make the counter anion a monovalent anion such as chlorine ion, bromine ion, iodine ion, nitrate ion, perchlorate ion, acetate ion or methylsulfate ion, or bivalent ion such as sulfate ion or methyl phosphate ion.
For use as the active component, the polymers of the present invention are usable singly, or at least two of them can be used in mixture.
The polymers of the invention can be in the form of a powder, granules, fibers, film or the like depending on the process for preparing the polymer.
In the case where the polymers of the invention are used, for example, as the active component of antibacterial compositions, these compositions are usable for a wide variety of applications, for example, for tap water, cooling water, slime control, pools, fishing nets, ship bottoms, underwater structures, food packaging materials, building materials, agricultural materials, medical products, materials or utensils for use in the oral cavity (toothbrushes, toothpastes, etc.), spectacle frames, cosmetics, clothes and household utensils.
The present antibacterial polymers are usable by known methods. For example, for the antibacterial surface treatment of articles, the article can be treated by being dipped in or sprayed with a solution prepared by dissolving one or at least two of the polymers in a suitable solvent. At this time, the polymer is usable as admixed with known polymers.
The materials for which the antibacterial polymers are usable are, for example, synthetic high polymers of any form such as polypropylene, polyethylene, polystyrene, polyester, polyamide, polyacrylate, polyurethane and polyvinyl chloride, natural high polymers such as cotton, wool, feathers, hemp, silk, paper and rubber, and further wood, glass, metal and ceramics.
These materials may be in the form of molded or shaped materials, or unprocessed materials. The material to be subjected to the antibacterial treatment can be in the form of yarns, fibers, film, sheet, grains, powder or the like.
The polymers of the present invention impart high antibacterial activity to these materials with high safety over a prolonged period of time.
When the antibacterial polymers are to be used, it is generally preferable to use the polymer as dissolved in methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulioxide or the like, or in a solvent mixture of such a solvent and acetone, tetrahydrofuran, benzene, toluene, xylene or the like. The concentration of the solution is 0.01 to 2.0 wt. %, preferably 0.1 to 1.0 wt. %. The substance to be given antibacterial properties is dipped in or sprayed with the solution, whereby the solution is applied to the surface, followed by drying to remove the solvent. It is desirable to dry the wet substance in a drying chamber at a temperature of 0.degree. to 80.degree. C., preferably 20.degree. to 60.degree. C. for 10 to 48 hours.
The antibacterial polymers are also excellent in underwater antisoiling properties. When to be used underwater for preventing soiling, the antibacterial polymer is usable as admixed with a known coating composition. Known substances containing an antisoiling component can be added to the mixture.
For underwater antisoiling applications, the antibacterial polymers are usable, for example, for fishing nets, ship bottoms, cooling water piping, buoys, dam gates, water tanks of culture facilities and underwater structures, and are very effective for preventing adhesion of sea weed, green layer, sea lettuce, barnacles, etc.
When the antibacterial polymers are to be used for underwater antisoiling applications, it is generally desirable to dissolve the polymer in a solvent such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, N,N-dimethylformamide or dimethyl sulfoxide, or in a solvent mixture of such a solvent and benzene, toluene, xylene or the like. The method of use can be a known method.
The known substance containing an antisoiling component and usable as admixed with the antibacterial polymer is not limited particularly. Examples of such substances are copper compounds, dithiocarbamate compounds, phenarsazine compounds, quaternary ammonium salt compounds, etc. Also usable as admixed with the antibacterial polymer are crosslinking agents, fillers, monomers, polymers and the like which have antisoiling activity.
Next, the coating composition usable as mixed with the antibacterial polymer may be any of those already known, which include, for example, acrylic acid resin, phthalic acid resin, aminoalkyd resin and synthetic resin emulsion compositions, lacquers, etc.