JP3389715B2 - Antibacterial resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial resin composition having excellent antibacterial properties and excellent surface appearance of a molded article. 2. Description of the Related Art ABS resin, HIPS, polyethylene,
Thermoplastic resins such as polypropylene and polyamide have excellent surface appearance, moldability, physical properties, and mechanical properties of molded products, so they can be used in electrical and electronic fields, office automation and home appliances, automobiles, toilet seats and bathrooms, etc. It is used in a wide range of fields such as sanitary, stationery, and miscellaneous goods. In recent years, there has been a problem that bacteria are generated in products used in these products and adversely affect human bodies. As a method of imparting antibacterial properties to these resins, there is a method of kneading a commercially available antibacterial fungicide. However, it is necessary to use a large amount of an antibacterial agent in order to increase the antibacterial property's immediate effect or durability, which deteriorates the appearance of a molded article. DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and expresses antimicrobial sustainability with a small amount of an antibacterial agent, and has excellent surface appearance of a molded article.
An object is to provide an antibacterial resin composition that can be used for a wide range of applications. The present invention relates to (A) 100 parts by weight of a styrene resin and (B) 0.01 parts of a silver antibacterial agent.
(A) a styrene-based resin obtained by emulsion polymerization and recovered by acid coagulation. Is what you do. [0003] The styrenic resin used in the present invention comprises:
(Graft) polymerization of (b) an aromatic vinyl compound or a monomer component comprising an aromatic vinyl compound and another monomer copolymerizable therewith in the presence or absence of (a) a rubbery polymer (Graft) polymer resin (rubber-modified aromatic vinyl resin) obtained by the above method, or a thermoplastic resin obtained by polymerizing the monomer component (b) and the graft polymer resin. It may be a blend-type graft copolymer resin obtained by blending, or may simply be a blend of (a) a rubbery polymer and a thermoplastic resin comprising the component (b). (A) The styrene resin is preferably (a) 5 to 70% by weight of a rubbery polymer and (b) an aromatic vinyl compound or another copolymerizable with the aromatic vinyl compound from the viewpoint of impact resistance. 95-30% by weight of a monomer component composed of a monomer
[However, (a) + (b) = 100% by weight] is a rubber-reinforced resin. Here, (a) the rubbery polymer used in the present invention includes, for example, polybutadiene, polyisoprene, styrene-butadiene copolymer (preferably having a styrene content of 5 to 60% by weight), silicone rubber, and styrene-isoprene copolymer. Polymer, acrylonitrile-butadiene copolymer, ethylene-α-olefin-based copolymer, ethylene-α-olefin-polyene copolymer, acrylic rubber, butadiene- (meth) acrylate copolymer, polyisoprene, styrene -Butadiene block copolymer, styrene-isoprene block copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated butadiene-based polymer, ethylene-based ionomer and the like. In addition, the styrene-butadiene block copolymer and the styrene-isoprene block copolymer include those having an AB type, ABA type, a taper type, a radial teleblock type, and the like. further,
The hydrogenated butadiene-based polymer is, in addition to the hydride of the block copolymer, a styrene block and a styrene-butadiene random copolymer block, and a 1,2-vinyl bond content in polybutadiene of 20% by weight. % Or less, and a hydride of a polymer comprising a polybutadiene block having a 1,2-vinyl bond content of more than 20% by weight. These (a) rubbery polymers are:
Used alone or in combination of two or more. The content of the rubbery polymer in the styrene resin is preferably 5 to 70% by weight, more preferably 5 to 60% by weight. Also,
The monomer constituting the component (b) is an aromatic vinyl compound or another monomer copolymerizable with the aromatic vinyl compound. As the aromatic vinyl compound constituting the component (b), styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-diethyl −
p-Aminoethylstyrene, N, N-diethyl-p-aminomethylstyrene, vinylpyridine, vinylxylene, monochlorostyrene, dichlorostyrene, monobromostyrene, fluorostyrene, ethylstyrene, vinylnaphthalene and the like. α-Methylstyrene is preferred. These aromatic vinyl compounds may be used alone or in combination of two or more.
Other monomers constituting the component (b) include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; methyl acrylate, ethyl acrylate,
Acrylic esters such as propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, dodecyl acrylate, octadecyl acrylate, phenyl acrylate and benzyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate Butyl methacrylate, amyl methacrylate, hexyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, phenyl methacrylate, benzyl methacrylate, and other methacrylic esters; maleic anhydride, itaconic anhydride, silicon anhydride Unsaturated acid anhydrides such as Rakon acid;
Unsaturated acids such as acrylic acid and methacrylic acid; maleimide, N-methylmaleimide, N-butylmaleimide, N
Imide compounds of α- or β-unsaturated dicarboxylic acids such as-(p-methylphenyl) maleimide, N-phenylmaleimide and N-cyclohexylmaleimide; epoxy compounds such as glycidyl methacrylate and allyl glycidyl ether; acrylamide and methacrylamide Unsaturated carboxylic acid amides; amino group-containing unsaturated compounds such as acrylamine, aminomethyl methacrylate, aminoethyl methacrylate, aminopropyl methacrylate and aminostyrene; 3-hydroxy-1-propene;
4-hydroxy-1-butene, cis-4-hydroxy-
2-butene, trans-4-hydroxy-2-butene,
Examples include hydroxyl-containing unsaturated compounds such as 3-hydroxy-2-methyl-1-propene, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate; and oxazoline-containing unsaturated compounds such as vinyl oxazoline. Other monomers preferred as component (b) include:
Examples include acrylonitrile, methacrylic acid, methyl methacrylate, maleic anhydride, N-phenylmaleimide, glycidyl methacrylate, and 2-hydroxyethyl methacrylate, and particularly preferably acrylonitrile, methyl methacrylate, N-phenylmaleimide, and 2-hydroxyethyl methacrylate. These other monomers can be used alone or in combination of two or more. The intrinsic viscosity of the methyl ethyl ketone soluble component in the styrene resin of the present invention (measured at 30 ° C. using methyl ethyl ketone as a solvent) is preferably from 0.2 to 2.0 dl / g. If the intrinsic viscosity is less than 0.2 dl / g, the impact resistance is poor, while if it exceeds 2.0 dl / g, the moldability is poor. This intrinsic viscosity can be controlled by a chain transfer agent, polymerization time, polymerization temperature, and the like. The graft ratio of a styrene resin containing a rubber component is usually 10 to 300% by weight.
If it is less than 10% by weight or more than 300% by weight, the impact resistance tends to decrease, which is not preferable. The styrene-based resin is preferably obtained by polymerizing by emulsion polymerization and then recovering the polymer by acid coagulation in which an acid is added to the emulsified and dispersed polymer emulsion to coagulate. Preferred acid coagulants for achieving the object of the present invention include sulfuric acid, acetic acid, nitric acid and hydrochloric acid, and more preferably hydrochloric acid, acetic acid or sulfuric acid. Particularly preferred is sulfuric acid or acetic acid. In addition, the styrenic resin recovered by the acid coagulation may be used in combination with another styrenic resin obtained by another polymerization method, for example, solution polymerization, within a range not to impair the object of the present invention. [0005] The component (B) of the present invention is a silver-based antibacterial agent. An organic or inorganic silver compound, and a substance having a porous structure (a porous structure) may be a silver compound and / or a silver compound. Examples thereof include those supporting a complex salt and those obtained by ion-exchanging silver ions in a porous structure. The silver-based antibacterial agent of the present invention may be a combination of other antibacterial metals, metal compounds, metal complex salts, metal ions, and the like. Other metals used herein include copper, zinc, magnesium, mercury, tin, lead, bismuth, cadmium, chromium, cobalt, nickel, iron, manganese, arsenic, antimony, barium and the like, preferably copper, zinc,
More preferably, such as magnesium, copper, zinc,
Particularly preferred is zinc. Examples of the silver compound include colloidal silver (colloidal silver), silver carbonate, silver chlorate, silver perchlorate, silver bromate, silver iodate, silver periodate, silver phosphate, silver diphosphate, and silver nitrate. , Silver nitrite, silver sulfate, silver tungstate, silver vanadate, silver thiocyanate, silver amide sulfate, silver borate, silver thiosulfate, silver oxide, silver peroxide, silver sulfide, silver fluoride, silver chloride, bromide Silver, silver iodide, silver acetate, silver benzoate, silver lactate, silver pyrophosphate, silver citrate, silver behenate, silver diethylcarbamate, silver stearate, silver carboxylate, silver tartrate, silver metasulfonate, silver trifluoro Silver acid salts, alkyl esters of phosphoric acid or phosphorous acid, silver salts of phenyl esters or alkyl phenyl esters, silver phosphofluoride, silver phthalocyanine, silver ethylenediaminetetraacetate, silver protein, etc. It is possible. Among these, preferred are colloidal silver, silver chlorate, silver perchlorate, silver carbonate, silver bromate,
Silver iodate, silver periodate, silver phosphate, silver diphosphate, silver nitrate, silver sulfate, silver tungstate, silver vanadate, silver citrate, silver thiocyanate, silver carboxylate, silver amide sulfate, silver thiosulfate , Silver chloride, silver oxide and silver peroxide. Particularly preferred are colloidal silver, silver oxide, silver phosphate, silver carbonate, silver iodate, silver pyrophosphate, silver citrate, silver tungstate, and silver chloride. As the copper compound, for example, copper nitrate (I
I), copper sulfate, copper perchlorate, copper acetate, potassium tetracyanocuprate, copper chloride and the like. Examples of the zinc compound include zinc nitrate (II), zinc sulfate, zinc perchlorate, zinc thiocyanate, zinc acetate, zinc chloride, zinc oxide, and the like. One or more of these metal compounds are used. This colloidal silver usually has a silver component of 0.02 to 1% by weight, a particle size of 50 mμ or less, and a pH of 7.0.
± 1.0, preferably 0.05 to 0.2
% By weight and a particle size of 10 mμ or less. Note that the antimicrobial activity of silver tends to increase as the particle size becomes finer. Examples of the carboxylic acid salts include the following carboxylic acid salts. An aliphatic saturated monocarboxylic acid having 1 to 30 carbon atoms, preferably 2 to 22 carbon atoms, for example, acetic acid, propionic acid, butyric acid, valeric acid, lauric acid, myristic acid, palmitic acid, stearic acid, docosanoic acid, and having 2 to 34 carbon atoms , Preferably 2
To 8 aliphatic saturated dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, suberic acid, sebacic acid, and aliphatic unsaturated carboxylic acids having 1 to 34, preferably 2 to 22 carbon atoms, such as oleic acid and erucic acid , Maleic acid, fumaric acid, carbocyclic carboxylic acids such as benzoic acid, phthalic acid, cinnamic acid, hexahydrobenzoic acid, abietic acid,
Hydrogenated abietic acid, hydrocarboxylic acid such as lactic acid,
Malic acid, tartaric acid, citric acid, salicylic acid, aminocarboxylic acids such as aspartic acid, glutamic acid. In the present invention, preferred salts of carboxylic acids are silver salts, for example, silver salts of aliphatic saturated monocarboxylic acids, particularly silver laurate, silver stearate, silver salts of aliphatic unsaturated carboxylic acids, especially silver oleate, And silver salts of carbocyclic carboxylic acids, especially silver benzoate and hydrogenated silver abietic acid. Further, examples of salts of alkyl esters, phenyl esters or alkylphenyl esters of phosphoric acid or phosphorous acid include the following, for example, silver salts. Monoalkyl or disilver salts of monoalkyl phosphate (C1 to C22) esters, monosilver or disilver salts of monoalkyl phosphite (C1 to C22) esters, dialkyl phosphate (carbon A silver salt of an ester of the formulas 1 to 22),
Mono- or di-silver salts of monophenyl phosphate,
Mono- or di-silver salt of monophenyl phosphite,
Monosilver salt of diphenyl phosphate, monosilver or disilver salt of mono [alkyl (C1-22) phenyl] phosphate, mono [alkyl (C1-22) phenyl] ester of phosphorous acid Monosilver salt or disilver salt,
Monosilver salt of di [alkyl (C1-22) phenyl] phosphate. Among them, preferred silver salts are mono- or di-silver salts of monoalkyl phosphates, particularly those having an alkyl group of 6 to 22 carbon atoms, more preferably di-silver salts of stearyl phosphate, dialkyl phosphates. Monosilver salts of esters, especially those having 6 to 22 carbon atoms in the alkyl group,
More preferably, a monosilver salt of dioctel phosphate and a monosilver salt of di (alkylphenyl) phosphate, particularly those having an alkyl group having 4 to 22 carbon atoms, more preferably di (4-t-butyl phosphate) Phenyl) and di (nonylphenyl) phosphate. Further, as the porous structure, silica gel, activated carbon, zeolite,
There are zirconium phosphate, calcium phosphate, hydrotalcite, hydroxyapatite, calcium-based ceramics, etc., those containing the above-mentioned metals and the above-mentioned metal compounds, those containing silver oxide or the like in soluble glass (JP-A-4-178433). Publication). The particle size of these molecular weights is preferably 50 μm or less, more preferably 0.1 to 10 μm. Among them, zeolite can be used in both natural products and synthetic products. [0007] Examples of the calcium-based ceramics include calcium phosphate, calcium carbonate, calcium silicate, and hydroxyapatite, with hydroxyapatite being particularly preferred. Hydroxyapatite is C
It has a composition of a ₁₀ (PO ₄ ) ₆ (OH) ₂ , and it is recognized that it has good adsorbability to proteins and lipids as a main component of bone and teeth, has good affinity with biological components, and has ion exchange ability. Have been. However, as described above, Ca / P (molar ratio) =
Synthesis of 10/6 hydroxyapatite from calcium and phosphate salts is difficult and uneconomical. On the other hand, it is easy to synthesize hydroxyapatite analogs having Ca / P (molar ratio) = 1.4 to 1.8 from calcium salts and phosphates, and these analogs are also similar to hydroxyapatite. It can be used in the present invention. The amount of the metal which exhibits the antibacterial property which is ion-exchanged or carried on the porous structure is not particularly limited,
0 wt% or less, preferably 0.001 to 30 wt%, more preferably 0.001 to 10 wt%. The most preferred antimicrobial agent is zeolite ion exchanged with silver or silver / zinc. As the antibacterial agent (B), an organic compound may be used in combination, and examples thereof include a benzimidazolate compound, an organic iodine compound, an ether compound, a haloalkyl compound, a nitrile compound, and a sulfone compound. Can be The amount of the antibacterial agent (B) used is 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, more preferably 0.05 to 3 parts by weight, per 100 parts by weight of the component (A).
1.5 parts by weight. If the amount is less than 0.01 part by weight, the antibacterial property is poor, and if it exceeds 5 parts by weight, the surface appearance of the molded article is poor. In order to improve the antimicrobial durability, which is the object of the present invention, it is preferable that the component (A) be subjected to emulsion polymerization and then coagulated and recovered with an acid. Those recovered by a coagulation method using a metal salt compound such as calcium chloride or magnesium chloride as a coagulant have poor persistence of antibacterial properties. In addition,
The antimicrobial resin composition of the present invention includes glass fibers, carbon fibers, metal fibers, glass beads, wollastonite, rock filler, calcium carbonate, talc, mica, glass free, kaolin, barium sulfate, graphite, molybdenum disulfide, Fillers such as magnesium oxide, zinc oxide whiskers, and potassium titanate whiskers can be used alone or in combination. Among these fillers, those having a fiber type of 6 to 60 μm and a fiber length of 30 μm or more are preferable as the shape of the glass fiber and the carbon fiber.
These fillers are generally used in the range of 5 to 150 parts by weight based on 100 parts by weight of the composition of the present invention. Further, various known additives may be added to the composition of the present invention. For example, there are a coupling agent, a flame retardant, an antioxidant, a plasticizer, a coloring agent, an antistatic agent, and silicone oil. Further, in the composition of the present invention, other thermoplastic resins can be blended with 100 parts by weight of the composition of the present invention, preferably in the range of 1 to 200 parts by weight, depending on the required performance. . Specifically, as other thermoplastic resins, polyethylene, polypropylene, polyamide-based elastomer, polyester-based elastomer, polyethylene glycol, polyethylene oxide, polyamide resin, polybutylene terephthalate, polyethylene terephthalate,
Polyacrylate, polycarbonate, polyphenylene ether, polyacetal, vinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, PPS, EV
A, EEA, EVOH and the like can be used alone or in combination of two or more. Particularly, it is preferable to add an anionic or nonionic antistatic agent because the antibacterial property is improved. The antimicrobial resin composition of the present invention can be obtained by kneading the components using various extruders, Banbury mixers, kneaders, rolls, and the like. A preferred production method is a method using a twin-screw extruder. Also,
When kneading the respective components, the respective components may be kneaded at once, or may be kneaded by a multi-stage addition method. The antibacterial resin composition of the present invention thus obtained is molded into various molded articles by injection molding, sheet extrusion, vacuum molding, heteromorphic molding, foam molding, injection press, press molding, blow molding and the like. be able to. When obtained by injection molding, the higher the injection speed, the better the antibacterial properties. Various molded products obtained by the above molding method are used for toilet seats, humidifiers, water purifiers, air conditioners, miscellaneous goods, stationery, other various home appliances, telephone parts and other parts, housings, etc., utilizing their excellent properties. Can be used. Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, parts and% are based on weight unless otherwise specified. Various evaluations in the examples are values measured as follows. Antibacterial property A flat molded product with a thickness of 1.6 mm x 50 mm x 50 mm
Samples were held in a gear oven maintained at 70 ° C. for the times shown in Tables 2 and 3. The specimen is inoculated with 0.2 ml of a bacterial solution of MRSA (mesicillin-resistant staphylococcus) (the number of bacteria per ml is about 10 ⁶ ), adhered to a polyethylene film, and stored at 35 ° C., at the start of storage and for 24 hours. Later, SCDLP agar medium [manufactured by Nippon Pharmaceutical Co., Ltd.]
The viable bacteria were washed out. About this wash-out solution, an agar plate culture method (35 ° C., 2 days) using a medium for measuring the number of bacteria
The number of viable bacteria was measured by the above method, and converted to the number of viable bacteria per sample. The initial number of bacteria tested in Examples and Comparative Examples was 3 ×
10 ⁵ . Further, the evaluation results of the antibacterial properties shown in Tables 2 and 3 are represented by using the following symbols. ◎: less than 5 × 10 ² △: less than 5 × 10 ⁴ 5 × 10 ² or more ×: 5 × 10 ⁴ or more Molded product surface appearance 1.0 mm × 150 mm × 150 mm flat plate molded with two pinpoint gates. The appearance of the weld portion and the surface other than the weld was visually evaluated according to the following evaluation criteria. ：: good appearance ×: poor appearance Reference Example (A) -1 to (A) -3 Polybutadiene latex A mixture of 40 parts (solid content 58%) of JSR # 0700, 250 parts of water and 5 parts of potassium rosinate was added with 0.2 part of sodium pyrophosphate, 0.2 parts of textrose, 0.004 parts of ferrous sulfate and 0.4 part of cumene hydroperoxide are added. Each of the monomers shown in Table 1 (60 parts in total) and t-dodecyl mercaptan 0.1% were added.
The three parts of the mixture were added dropwise to the reactor with stirring under a nitrogen stream. The addition time was 4 hours and the polymerization temperature was 60 ° C. The polymerization was almost complete. As a result, the obtained resin latex was coagulated using the coagulant shown in Table 1, dried and dried, and used for evaluation. (A) -4 to (A) -7 In a mixed solution of 250 parts of water and 5 parts of potassium rosinate, 0.2 part of sodium pyrophosphate, 0.2 part of dextrose, 0.004 part of ferrous sulfate, and cumene 0.4 parts of hydroperoxide are added. Each of the monomers shown in Table 1 (total 100
Part) and 0.4 part of t-dodecyl mercaptan were stirred and added dropwise to the reactor under a nitrogen stream. The dripping time is 3
The polymerization temperature was 60 ° C over time. After completion of the dropping, 0.04 part of sodium pyrophosphate, 0.04 part of dextrose, 0.001 part of ferrous sulfate, and 0.0% of cumene hydroperoxide
8 parts were added and the polymerization temperature was maintained at 70 ° C. for 1 hour. The polymerization was almost complete. As a result, the obtained resin latex was coagulated using the coagulant shown in Table 1, dried and dried, and used for evaluation. (A) -8 Polymers having the respective monomer composition ratios shown in Table 1 were subjected to solution polymerization using toluene as a solvent and recovered without using a coagulant. Examples 1 to 4 Powders blended with the composition shown in Table 2 were pelletized and subjected to injection molding. Table 2 shows the evaluation results.
Table 2 shows that the resin composition of the present invention has excellent antimicrobial durability. Comparative Examples 1 to 6 Powders blended with the composition shown in Table 3 were pelletized and subjected to injection molding. Table 3 shows the evaluation results.
From the comparison between Tables 2 and 3, it is found that blending of the product solidified with CaCl ₂ or MgCl ₂ is inferior in persistence of antibacterial activity to that of blending only the product solidified and recovered with H ₂ SO _4. I understand. In addition, Zeomic XAW10D (silver ion exchange type) manufactured by Sinanen Zeomics was used as the antibacterial agent. Description of Comparative Example In Comparative Example 1, since the copolymer (A) -7 is a salt-coagulated product of CaCl ₂ , the antibacterial life is short. Comparative Example 2
Since the amount of the antibacterial agent added is small, no antibacterial property is exhibited. Comparative Example 3 was obtained using copolymers (A) -2 and (A)
Since both -7 are CaCl ₂ salt coagulated products, the antibacterial life is shorter than that of Comparative Example 1. Comparative Example 4 has a short antibacterial life because the copolymer (A) -3 is a salt-coagulated product of MgCl ₂ . In Comparative Example 5, although the copolymers (A) -2 and (A) -7 were both salt-coagulated products of CaCl ₂ , the antibacterial life was good because the added amount of the antibacterial agent was large. However, the surface appearance is reduced. The antibacterial resin composition of the present invention is excellent in antibacterial lifespan and surface appearance of molded articles, and can be used in a wide range of applications such as humidifiers, water purifiers, air conditioners, toilet seats, stationery, miscellaneous goods, It is useful for various other home appliances, parts such as telephones, housings, and the like. [Table 1] [Table 2] [Table 3]

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hisao Nagai 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-8-143740 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 51 / 04,55 / 02

Claims (1)

(57) [Claim 1] (A) Copolymerizable with an aromatic vinyl compound or an aromatic vinyl compound and an aromatic vinyl compound in the presence or absence of a rubbery polymer 100 parts by weight of a styrene resin obtained by emulsion polymerization of another vinyl monomer and (B) 0.01 to 5 parts by weight of a silver antibacterial agent, wherein (A) is recovered by acid coagulation An antibacterial resin composition, characterized in that: