JP5641302B2 - Antibacterial resin composition - Google Patents

Description

  The present invention relates to an antibacterial resin composition.

  Conventionally, resin has been introduced in a wide range of fields such as sanitary fields around toilet seats, kitchens, and bathrooms, medical equipment, sundries, and building materials, as well as electrical / electronic related parts, OA related parts, and automotive parts. Yes. In particular, it has been pointed out that bacteria and sputum breeding in products used in the sanitary field and medical devices have adverse effects on the human body, and it is preferable to impart antibacterial properties. In addition, with the recent increase in the building level, indoors that have become warmer due to an increase in the degree of hermetic sealing are likely to condense, and the number of building materials imparted with antibacterial properties is increasing. Furthermore, anti-bacterial properties are often required due to the increasing cleanliness even in electrical / electronic related parts, OA related parts, and automotive parts.

  As a method for imparting antibacterial properties, there is a method in which an antibacterial agent is kneaded into a thermoplastic resin or a thermosetting resin, or the antibacterial agent is applied to the surface. At present, inorganic antibacterial agents are mainly used for kneading as antibacterial agents, and organic antibacterial agents are mainly applied in liquid form to products. Representative examples of inorganic antibacterial agents include zeolites substituted with metals such as silver and synthetic minerals (see Patent Document 1), and examples of organic antibacterial agents include chlorohexidine and quaternary ammonium salts ( Patent Document 2). However, inorganic antibacterial agents have problems such as inactivation in an environment where chlorine, sulfur, etc. coexist, inducing action of allergic symptoms, and coloration of molded products over time due to discoloration of metal compounds. In addition, organic antibacterial agents obtained by organic chemical synthesis exhibit a strong antibacterial effect in a very small amount, but have low safety for the human body and are difficult to use for life-related uses such as food packaging.

  On the other hand, among organic antibacterial agents, naturally-derived antibacterial components are considered to have high safety, and various naturally-derived antibacterial components are being studied. As organic antibacterial agents derived from natural products, there are various kinds such as hinokitiol, wasaolo (active ingredient: allyl isothiocyanate), wasabi, ginger, and the like. However, although there is an advantage that it is derived from a natural product and is safe, it has a drawback that it generally cannot withstand the processing temperature of the resin due to its low heat resistance. In addition, there are problems such as difficulty in obtaining due to limited supply, and addition of other additives in order to improve compatibility with the resin.

  Lignin, which is one of naturally derived components, is also used as an antibacterial agent (see Patent Document 3). The only commercially available lignins are lignin sulfonates such as sodium lignin sulfonate, calcium lignin sulfonate, magnesium lignin sulfonate, and the like. Conventionally, these lignin sulfonates have been used as antibacterial agents. However, since these lignin sulfonates have high polarity, there is a problem that they are difficult to dissolve and disperse in thermoplastic resins such as PP and PE having low polarity. Moreover, since lignin sulfonate is water-soluble, there was a problem in water resistance when kneaded with a thermoplastic resin.

JP 2007-091501 A Japanese Patent No. 3502140 Japanese Patent Laid-Open No. 11-152410

  Therefore, an object of the present invention is to provide an antibacterial resin composition using lignin that is a plant-derived component, has high safety to the human body, and is excellent in antibacterial properties.

The present invention is as follows.
(1) An antibacterial resin composition containing lignin and a thermoplastic resin, the lignin being a separation technique using water, crushing plants by hydrolysis and physical crushing, and washing with water The lignin obtained by removing the water-soluble component, separating from the cellulose component and hemicellulose component, and dissolving in an organic solvent, having a weight average molecular weight of 100 to 7000 and a sulfur atom content of 0.5 mass. %, And soluble in an organic solvent. Solvent solubility of acetone, cyclohexanone, tetrahydrofuran, ethylene glycol, and N-methyl-2 is obtained when 5 g of lignin is added to 95 ml of solvent and dissolved. -It dissolves in pyrrolidone at 25 ° C, and dissolves in methanol, ethanol and methyl ethyl ketone at 50-70 ° C. RESIN is port Riechiren are those selected from and polypropylene, antibacterial resin composition which comprises 0.01 to 50% by weight of lignin as a non-volatile content.
(2 ) A molded product obtained using the antibacterial resin composition described in (1 ) above.

  ADVANTAGE OF THE INVENTION According to this invention, the antimicrobial resin composition excellent in safety | security (antimicrobial property) was able to be provided by using the lignin which is a plant origin component.

Hereinafter, the present invention will be described in more detail.
The present invention is an antibacterial resin composition comprising lignin and a thermoplastic resin or a thermosetting resin, wherein the lignin is soluble in an organic solvent, and lignin is contained in an amount of 0.01 to 50% by mass as a nonvolatile content. An antibacterial resin composition. An antibacterial resin composition containing lignin as a nonvolatile content, preferably 0.01 to 20% by mass, and further 0.1 to 10% by mass is preferable. When the addition amount is less than 0.01% by mass, the phenolic hydroxyl group exhibiting antibacterial properties hardly appears on the surface of the cured product (molded product) of the antibacterial resin composition. If the antibacterial property is inferior and the addition amount exceeds 50% by mass, the appearance and strength of the cured product (molded product) of the antibacterial resin composition may be inferior. The antibacterial resin composition of the present invention may contain either one or both of a thermoplastic resin and a thermosetting resin.

The weight average molecular weight of lignin is preferably 100 to 7000, more preferably 200 to 5000, and particularly preferably 500 to 4000 in terms of polystyrene. When the weight average molecular weight of lignin exceeds 7000, the solubility to an organic solvent will fall. If the weight average molecular weight is less than 100, an antibacterial resin composition utilizing the structure of lignin may not be obtained.
The weight average molecular weight was measured by gel permeation chromatography (GPC), and a value converted to standard polystyrene was used.

  The basic skeleton of lignin is generally a crosslinked polymer having a hydroxyphenylpropane unit as a basic unit. Trees form an interpenetrating network (IPN) structure of hydrophilic linear polymer polysaccharides (cellulose and hemicellulose) and hydrophobic cross-linked lignin. Lignin accounts for about 25% by weight of trees and has an irregular and extremely complex chemical structure of polyphenols. Phenols are excellent in flame retardancy because they easily form graphite during combustion. In addition, it has a characteristic structure of having many phenolic hydroxyl groups and is strongly adsorbed to bacteria and exhibits antibacterial activity by suppressing their growth. The present invention provides an antibacterial resin composition having flame retardancy and antibacterial properties by making use of this complex structure obtained from plants as it is and using it as an additive to a thermoplastic resin or a thermosetting resin. It is.

  There are no particular restrictions on the raw material of lignin. Conifers such as cedar, pine and cypress, broad-leaved trees such as beech, bamboo, rice straw, bagasse and the like are used. Examples of methods for separating and taking out lignin from trees include kraft method, sulfuric acid method, and explosion method. Many of the lignins currently produced in large quantities are obtained as residues during the production of cellulose, which is a raw material for paper and bioethanol. Examples of lignin that can be obtained include lignin sulfonate that is produced as a by-product mainly by the sulfuric acid method. Other examples include alkaline lignin, organosolv lignin, solvolysis lignin, filamentous fungus treated wood, dioxane lignin and milled wood lignin, and explosive lignin. The lignin described above can be used regardless of the method of taking out the lignin used in the present invention.

  When taking out, components other than lignin, such as cellulose and hemicellulose, may be contained to some extent. Also included are lignin derivatives prepared by acetylation, methylation, halogenation, nitration, sulfonation, reaction with sodium sulfide or hydrogen sulfide, and the like.

As a method for obtaining lignin as a main raw material, a method using a separation technique using water is preferable. The lignin used is preferably a lignin obtained by separating it from a cellulose component and a hemicellulose component by a treatment method using only water and dissolving it in an organic solvent. Moreover, as a method for obtaining lignin, a steam explosion method is preferred. The steam explosion method crushes plants in a short time by hydrolysis with high-temperature and high-pressure steam and a physical crushing effect by instantaneously releasing the pressure.
The conditions for steam explosion are not particularly limited. Usually, the raw material is placed in a pressure vessel for a steam explosion apparatus, 3-4 MPa of steam is injected, left to stand for 1-15 minutes, and then the pressure is instantaneously released for explosion. To do. The organic solvent-soluble lignin is also referred to as steam explosion lignin. The raw material is not particularly limited as long as lignin can be extracted. .
This method is a clean separation method because only water is used without using sulfuric acid, sulfite or the like, compared with other separation methods such as sulfuric acid method and kraft method. In this method, lignin containing no sulfur atom in the lignin or lignin having a low content of sulfur atoms can be obtained. Usually, the content of sulfur atoms in lignin is preferably 2% by mass or less, more preferably 1% by mass or less, and more preferably 0.5% by mass or less. If the sulfur atom content exceeds 2% by mass, hydrophilic sulfonic acid groups increase, so that the solubility in organic solvents may be reduced. The present inventors have further found that the molecular weight of lignin can be controlled from the blasted product by extraction with an organic solvent.

  Since the lignin obtained by the steam explosion method is less polar than the conventional lignin sulfonate, it is easier to dissolve and disperse in a low-polarity thermoplastic resin such as PE or PP, making a uniform molded body easier. Can be obtained. Moreover, since it is insoluble in water, the water resistance when formed into a molded body (cured product of the antibacterial resin composition) is good.

  The organic solvent used in the extraction of lignin used in the present invention is one or a mixture of two or more kinds of alcohol solvents, a hydrous alcohol solvent in which alcohol and water are mixed, another organic solvent, or a hydrous organic solvent in which water is mixed. Can be used. It is preferable to use ion exchange water as water. The water content of the mixed solvent with water is preferably 0% by mass to 70% by mass. Since lignin used in the present invention has low solubility in water, it is difficult to extract lignin using only water as a solvent. Moreover, it is possible to control the weight average molecular weight of the lignin obtained by selecting the solvent to be used.

  The thermoplastic resin used in the antibacterial resin composition of the present invention can be arbitrarily selected from thermoplastic resins used as ordinary molding materials. Examples of such materials include, but are not limited to, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycaprolactone (PCL), acrylonitrile butadiene, and the like. -Styrene resin (ABS), polystyrene (PS), methacrylic resin (PMMA), polyamide (PAI), polycarbonate (PC), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyacetal (POM), modified polyphenylene ether Examples thereof include tellurium (PPE), polysulfone (PSF), liquid crystal polymer (LCP), acrylonitrile / styrene resin (AS), and various thermoplastic elastomers. More preferably, it is a plant-derived thermoplastic resin from the viewpoint of reducing fossil resource usage. Specifically, polylactic acid (PLA), esterified starch, polyhydroxyalkanoic acid (PHA), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), succinic acid, itaconic acid and 1,3-propanediol Polyester resin synthesized using 1,4-butanediol or the like as a monomer can be used, and one kind can be used alone or two or more kinds can be used in combination.

  The thermosetting resin used in the antibacterial resin composition of the present invention can be arbitrarily selected from thermosetting resins used as ordinary molding materials. Examples of such materials include, but are not limited to, epoxy resins, phenol resins, furan resins, urea resins, melamine resins, unsaturated polyester resins, and silicon resins.

  Examples of the epoxy resin include bisphenol A glycidyl ether type epoxy, bisphenol F glycidyl ether type epoxy, bisphenol S glycidyl ether type epoxy, bisphenol AD glycidyl ether type epoxy, phenol novolac type epoxy, biphenyl type epoxy, and cresol novolak type epoxy. It is done. Further, an epoxy resin obtained from a naturally-derived substance is preferable from the viewpoint of reducing the environmental load. Specific examples include epoxidized soybean oil, epoxidized fatty acid esters, epoxidized linseed oil, and dimer acid-modified epoxy resin.

  Examples of the phenol resin include those obtained by reacting phenols such as phenol and cresol with formaldehyde and the like to synthesize a novolac type phenol resin and the like, and by adding hexamethylenetetramine and the like to this. For example, phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol and other phenols and / or naphthols such as α-naphthol, β-naphthol, dihydroxynaphthalene and formaldehyde, benzaldehyde, salicylaldehyde, etc. Phenol aralkyl resins synthesized from novolak-type phenol resins, phenols and / or naphthols, and dimethoxyparaxylene or bis (methoxymethyl) biphenyl obtained by condensation or cocondensation with a compound having an aldehyde group , Aralkyl type phenol resins such as biphenylene type phenol aralkyl resins and naphthol aralkyl resins, phenols and / or naphthols and dicyclopentadiene Dicyclopentadiene-type phenol novolac resin, dicyclopentadiene-type naphthol novolak resin and other dicyclopentadiene-type phenol resins, triphenylmethane-type phenol resins, terpene-modified phenol resins, paraxylylene and / or metaxylylene-modified Examples thereof include phenol resins, melamine-modified phenol resins, cyclopentadiene-modified phenol resins, and phenol resins obtained by copolymerizing two or more of these. These may be used alone or in combination of two or more.

  Examples of the furan resin include furfural resin, furfural phenol resin, furfural ketone resin, furfuryl alcohol resin, and furfuryl alcohol phenol resin. Examples of the urea resin include polymerization reaction products (dehydration condensation reaction products) such as urea and formaldehyde. Examples of the melamine resin include polymerization reaction products such as melamine and formaldehyde.

Examples of the unsaturated polyester resin include resins that are obtained by dissolving an unsaturated polyester obtained from an unsaturated polybasic acid or the like and a polyhydric alcohol in a monomer that is polymerized therewith. Examples of unsaturated polybasic acids include phthalic acid, isophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, succinic acid, itaconic acid, citraconic acid, and the like. Polyhydric alcohol includes polyethylene glycol. , Polypropylene glycol, polyethylene / polypropylene glycol, trimethylolpropane, diethylene glycol, 1,4-butanediol, 1,6-hexane glycol and the like.
Examples of the silicon resin include those having an organopolysiloxane as a main skeleton.

  The thermosetting resin curing agent and curing catalyst are not particularly limited. For example, amine compounds, compounds such as polyaminoamide compounds synthesized from amine compounds, tertiary amine compounds, imidazole compounds, hydrazide compounds, melamine compounds. , Acid anhydrides, phenol compounds, thermal latent cationic polymerization catalysts, dicyanamide and derivatives thereof. These can be used alone or as a mixture of two or more.

  In the antibacterial resin composition of the present invention, various additive components, plasticizers (mineral oil, silicone oil, etc.), lubricants, stabilizers, antioxidants, ultraviolet absorbers, mold release agents, antifungal agents as necessary Inorganic fillers, organic fillers, and the like can also be blended when polymer components are polymerized or when polymer molded bodies are molded. Moreover, you may use together with another well-known flame retardant and antibacterial agent.

  The antibacterial resin composition of the present invention can be obtained by kneading the lignin into the thermoplastic resin or the thermosetting resin using a melt kneader. Examples of the kneading apparatus used here include a roll, a banbury, a kneader, a kneading extruder, and the like, and a method using a kneading extruder is preferable. A single-screw or twin-screw extruder is preferably used as the kneading extruder. Although the temperature at the time of kneading is not specifically limited, the range of 140-280 degreeC is preferable, 160-250 degreeC is more preferable, 180-230 degreeC is further more preferable. If the temperature is too low, the solubility or fluidity of lignin is poor, and if the temperature is too high, the antibacterial resin composition may be thermally decomposed and the physical properties may be deteriorated. In addition, when adding the various additive components described above, lignin, thermoplastic resin, and additive components may be mixed together. After kneading a part of the components first, the remaining components are divided all at once or in multiple stages. Then, it may be added and kneaded.

  The antibacterial resin composition of the present invention can be used in the form of a varnish after dissolving in an organic solvent. Organic solvents contained in the antibacterial resin composition or organic solvents used for extraction of lignin include alcohol, toluene, benzene, N-methylpyrrolidone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ether, methyl cellosolve (ethylene glycol monomethyl ether) , Cyclohexanone, dimethylformamide, methyl acetate, ethyl acetate, acetone, tetrahydrofuran and the like, and two or more of these can be used in combination.

  Alcohols include monools such as methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, n-hexanol, benzyl alcohol, cynohexanol, ethylene glycol, diethylene glycol, 1,4-butanediol, , 6-hexanediol, trimethylolpropane, glycerin, triethanolamine and other polyols. Further, an alcohol obtained from a natural substance is more preferable from the viewpoint of reducing environmental load. Specifically, methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, ethylene obtained from natural substances Examples include glycol, glycerin, and hydroxymethylfurfural.

  The molded product obtained by curing the antibacterial resin composition of the present invention can be molded into an arbitrary shape. For example, it can be used for various parts in a wide range of fields such as electrical / electronic related parts, OA related parts or automobile parts, sanitary parts such as toilet seats / kitchen / bathrooms, miscellaneous goods, and building materials. Moreover, since the molded object which consists of an antibacterial resin composition of this invention has content of lignin in an antibacterial resin composition being 50 mass% or less, it is excellent also in the external appearance.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, the scope of the present invention is not limited to these Examples.

( Reference Example 1 )
(Extraction of lignin)
Bamboo was used as a lignin extraction raw material. Bamboo material cut to an appropriate size was placed in a 3 L pressure-resistant container of a steam explosion apparatus, 3.5 MPa of steam was injected, and held for 4 minutes. Thereafter, the valve was rapidly opened to obtain an explosion-treated product. The explosion-treated product obtained until the pH of the cleaning solution reached 6 or more was washed with water to remove water-soluble components. Thereafter, residual moisture was removed with a vacuum dryer. After adding 300 ml of acetone as an extraction solvent to 100 g of the obtained dried product, the mixture was stirred for 10 minutes, and then the fiber material was removed by filtration. The extraction solvent was removed from the obtained filtrate to obtain lignin. The obtained lignin was a brown powder at room temperature (25 ° C.).

(Lignin analysis)
The solvent solubility was evaluated by adding 5 g of the lignin to 95 ml of an organic solvent. When it melt | dissolved easily at normal temperature (25 degreeC), it evaluated as (circle), when it melt | dissolved at 50-70 degreeC, (triangle | delta), and when it did not melt | dissolve even if heated, it evaluated as x. As a result of evaluating the solubility as acetone, cyclohexanone, tetrahydrofuran, ethylene glycol, N-methyl-2-pyrrolidone as the solvent group 1 and methanol, ethanol, and methyl ethyl ketone as the solvent group 2, all of the solvents in the solvent group 1 are ○, In all cases, the evaluation was Δ.

  The content of sulfur atoms in lignin was quantified by combustion decomposition-ion chromatography. As the apparatus, an automatic sample combustion apparatus (AQF-100) manufactured by Mitsubishi Chemical Analytech Co., Ltd. and an ion chromatograph (ICS-1600) manufactured by Nippon Dionex Co., Ltd. were used. The content rate of the sulfur atom in the said lignin was 0.1 mass%. Furthermore, the molecular weight of lignin was measured by gel permeation chromatography (GPC) equipped with a differential refractometer. Polystyrene having a low polydispersity was used as a standard sample, the mobile phase was used as tetrahydrofuran, and gel packs GL-A120S and GL-A170S manufactured by Hitachi High-Technologies Corporation were connected in series as columns to measure the molecular weight. Its weight average molecular weight was 2400.

  The hydroxyl equivalent of the lignin (organic solvent soluble lignin) obtained above was determined by measuring the hydroxyl value by acetic anhydride-pyridine method and the acid value by potentiometric titration (the units of hydroxyl equivalent and epoxy equivalent below are gram). / Equivalent and hereinafter expressed as g / eq.). The hydroxyl equivalent of acetone-extracted bamboo-derived lignin is 140 g / eq. Met. The molar ratio (hereinafter P / A ratio) of the phenolic hydroxyl group and alcoholic hydroxyl group of lignin was determined by the following method. An acetylation treatment of 2 g of lignin was performed, the unreacted acetylating agent was distilled off, and the dried product was dissolved in deuterated chloroform and analyzed by 1H-NMR (manufactured by BRUKER, V400M, proton fundamental frequency 400.13 MHz). It was measured. Determine the molar ratio from the integral ratio of protons derived from acetyl groups (derived from acetyl groups bonded to phenolic hydroxyl groups: 2.2 to 3.0 ppm, derived from acetyl groups bonded to alcoholic hydroxyl groups: 1.5 to 2.2 ppm). As a result, the P / A ratio was 2.2 / 1.0.

(Molding of antibacterial resin composition)
After putting 99.99 g of polylactic acid (REVODE manufactured by Zhejiang Kaisei Biological Materials Co., Ltd.), which is a plant-derived thermoplastic resin, into a kneader (Toyo Seiki Co., Ltd., Labo Plast Mill, Model 4C150), 0.01 g of the above lignin (organic solvent soluble lignin) was added. Therefore, an antibacterial resin composition containing 0.01% by mass of lignin and having a plant-derived component ratio of 100% by mass was obtained.
Hereinafter, the content of lignin is in the nonvolatile content of the antibacterial resin composition.
Further, the antibacterial resin composition was kneaded at 180 ° C. for 5 minutes, and then press molded under the conditions of 1 MPa, 180 ° C. and 5 minutes to obtain a molded body.

(Appearance evaluation)
The appearance of the obtained molded body was visually evaluated.
No coloration due to lignin addition or pale, smooth surface shape and suitable as a molded product ◎, coloration due to lignin addition but smooth surface shape and suitable as a molded product ○, coloration due to lignin In addition, the lignin kneading degree was not uniform or the surface shape was poor, and it was not suitable as a molded article.
The antibacterial resin composition of Example 1 obtained above was evaluated as ◎.

(Antimicrobial test)
According to JIS Z2801, antibacterial activity against Staphylococcus aureus and Escherichia coli was evaluated. On a test piece (molded body), 0.4 mL of a bacterial solution (viable cells of 2.5 to 10 × 10 5 cells / mL) was seeded, covered with a film, and cultured at 35 ° C. ± 1 ° C. for 24 hours. In order to measure the number of viable bacteria on the test piece (molded body), sampling was performed, the sample was appropriately diluted, and cultured in an agar plate culture at 35 ° C. ± 1 ° C. for 48 hours to obtain the viable cell count.
R = [Log (B / A) -log (C / A)] = [Log (B / C)]
R: antibacterial activity value A: average number of viable bacteria immediately after inoculation in unprocessed test pieces (pieces)
B: Average number of viable cells after 24 hours in unprocessed test piece
C: Average number of viable bacteria after 24 hours in antibacterial processed test piece
An antibacterial activity value of 2 or more was considered to be antibacterial. The antibacterial activity value of the molded antibacterial resin composition was 3.2 and 2.2 for Escherichia coli and Staphylococcus aureus, respectively.

( Reference Example 2 )
(Extraction and analysis of lignin)
Lignin was obtained in the same manner as in Reference Example 1 except that methanol was used as the extraction solvent. Elemental analysis and molecular weight measurement were performed in the same manner as in Reference Example 1. As a result, the sulfur atom content in lignin was 0.1% by mass, and the weight average molecular weight was 1,900. As a result of evaluating the solvent solubility in the same manner as in Reference Example 1 , the solvent group 1 was evaluated as “good” and the solvent group 2 was evaluated as “good”. The molar ratio of the phenolic hydroxyl group to the alcoholic hydroxyl group (hereinafter referred to as P / A ratio) of lignin was measured in the same manner as in Reference Example 1 . The P / A ratio of the lignin obtained in Reference Example 2 was 1.6 / 1.0. As a result of measuring the hydroxyl equivalent of the lignin (organic solvent-soluble lignin) obtained in the same manner as in Reference Example 1 , the hydroxyl equivalent was 120 g / eq. Met.

(Molding and appearance evaluation of antibacterial resin composition, antibacterial test)
An antibacterial resin composition was obtained in the same manner as in Reference Example 1 except that the lignin extracted from methanol was used and the lignin addition amount was 0.1 g and the polylactic acid addition amount was 99.9 g. The obtained resin composition contained 0.1% by mass of lignin, and the plant-derived component ratio was 100% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , it was judged as ◎. Moreover, as a result of performing an antibacterial test similarly to Reference Example 1 , the antibacterial activity values were 6.0 and 4.5 for Escherichia coli and Staphylococcus aureus, respectively, and were judged to have antibacterial properties.

(Example 1 )
The antibacterial resin composition was the same as in Reference Example 1 except that 0.1 g of lignin described in Reference Example 1 was added and 99.9 g of polyethylene (PE), which is a petroleum-derived thermoplastic resin, was used instead of polylactic acid. Got. The obtained antibacterial resin composition contained 0.1% by mass of lignin, and the plant-derived component ratio was 0.1% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , it was judged as ◎. Moreover, as a result of conducting the antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 5.9 and 4.6 for Escherichia coli and Staphylococcus aureus, respectively.

(Example 2 )
An antibacterial resin composition was obtained in the same manner as in Reference Example 1 except that 1 g of lignin described in Reference Example 1 was added and 99 g of polyethylene (PE), which is a petroleum-derived thermoplastic resin, was used instead of polylactic acid. The obtained resin composition contained 1% by mass of lignin, and the plant-derived component ratio was 1% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , it was judged as ◎. In addition, as a result of conducting the antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 6.2 and 4.6 for Escherichia coli and Staphylococcus aureus, respectively, and were judged to have antibacterial properties.

(Example 3 )
An antibacterial resin composition was obtained in the same manner as in Reference Example 1 except that 1 g of lignin described in Reference Example 1 was added and 99 g of polypropylene (PP), which is a petroleum-derived thermoplastic resin, was used instead of polylactic acid. The obtained resin composition contained 1% by mass of lignin, and the plant-derived component ratio was 1% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , it was judged as ◎. Moreover, as a result of performing the antibacterial test similarly to Reference Example 1 , the antibacterial activity values were 6.3 and 4.8 for E. coli and Staphylococcus aureus, respectively.

(Example 4 )
An antibacterial resin composition was obtained in the same manner as in Reference Example 1 except that 50 g of lignin described in Reference Example 1 was added and 50 g of polypropylene (PP), which is a petroleum-derived thermoplastic resin, was used instead of polylactic acid. The obtained resin composition contained 50% by mass of lignin, and the plant-derived component ratio was 50% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , it was judged as ◯. Moreover, as a result of conducting an antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 6.5 and 5.1 for Escherichia coli and Staphylococcus aureus, respectively.

(Comparative Example 1)
A resin composition was obtained in the same manner as in Reference Example 1 except that 0.009 g of lignin described in Reference Example 1 was added and the amount of polylactic acid added was 99.991 g. The obtained resin composition contained 0.009% by mass of lignin and the plant-derived component ratio was 100% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , it was judged as ◎. Moreover, as a result of conducting an antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 1.8 and 1.7 for Escherichia coli and Staphylococcus aureus, respectively.

(Comparative Example 2)
A resin composition was obtained in the same manner as in Reference Example 1 except that 0.009 g of lignin described in Reference Example 1 was added and 99.991 g of polyethylene (PE) was used instead of polylactic acid. The obtained resin composition contained 0.009% by mass of lignin, and the plant-derived component ratio was 0.009% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Example 1, it was judged as ◎. Moreover, as a result of conducting an antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 1.7 and 1.7 for Escherichia coli and S. aureus, respectively.

(Comparative Example 3)
A resin composition was obtained in the same manner as in Reference Example 1 except that 52 g of lignin described in Reference Example 1 was added and 48 g of polypropylene (PP) was used instead of polylactic acid. The obtained resin composition contained 52% by mass of lignin and had a plant-derived component ratio of 52% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , the result was x. Moreover, as a result of conducting the antibacterial test similarly to Reference Example 1 , the antibacterial activity values were 6.5 and 5.3 for Escherichia coli and Staphylococcus aureus, respectively, and were judged to have antibacterial properties.

(Comparative Example 4)
(Analysis of lignin sulfonate)
A resin composition was obtained using lignin sulfonate (Vanilex N, manufactured by Nippon Paper Industries Co., Ltd.) instead of lignin described in Reference Example 1 . As a result of measuring the content of sulfur atoms in the same manner as in Reference Example 1 , the content of sulfur atoms in the lignin sulfonate was 3% by mass. Further, the weight average molecular weight was measured by high performance liquid chromatography (C-R4A) manufactured by Shimadzu Corporation and calculated by a calibration curve using standard polystyrene. The mobile phase was used as DMF + LiBr (0.06 mol / L) + phosphoric acid (0.06 mol / L), and two gel packs GL-S300MDT-5 manufactured by Hitachi High-Technologies Corporation were connected in series as a column for molecular weight measurement. went. Its weight average molecular weight was 11,000. Further, the solubility in organic solvents was evaluated in the same manner as in Example 1. As a result of evaluating the solubility using acetone, cyclohexanone, tetrahydrofuran, methanol, ethanol, and methyl ethyl ketone as the solvent, it was insoluble in all the solvents.

(Molding of resin composition)
Instead of the lignin described in Reference Example 1 , 0.1 g of the lignin sulfonate insoluble in the organic solvent was added, and the amount of polylactic acid was changed to 99.9 g. Obtained. The obtained resin composition contained 0.1% by mass of lignin sulfonate, and the plant-derived component ratio was 100% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , the result was x. Moreover, as a result of conducting the antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 3.9 and 4.0 for Escherichia coli and Staphylococcus aureus, respectively.

(Comparative Example 5)
Instead of the lignin described in Reference Example 1 , 50 g of lignin sulfonate (Vanilex N, manufactured by Nippon Paper Industries Co., Ltd.) insoluble in organic solvents was added, and 50 g of polypropylene (PP) was used instead of polylactic acid. A resin composition was obtained in the same manner as in Reference Example 1 . The obtained resin composition contained 50% by mass of lignin sulfonate, and the plant-derived component ratio was 50% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , the result was x. Moreover, as a result of conducting an antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 4.2 and 4.1 for Escherichia coli and Staphylococcus aureus, respectively.

(Reference Example 3 )
(Molding of antibacterial resin composition)
Kneading machine (Toyo Seiki Co., Ltd.) 230 g of epoxidized soybean oil (Eposizer W-100-EL, manufactured by DIC Corporation), which is a plant-derived thermosetting resin, and 174 g of phenol resin (XLC-LL, manufactured by Mitsui Chemicals, Inc.) The product was put into a company-made Laboplast mill, model 4C150) and kneaded at 180 ° C., and then 0.041 g of lignin described in Reference Example 1 was added and sufficiently kneaded. Further, 1 g of Curazole 2PZ-CN (manufactured by Shikoku Chemicals Co., Ltd., 1-cyanoethyl-2-phenylimidazole) was added as a curing accelerator and kneaded. An antibacterial resin composition containing 0.01% by mass of lignin and 57% by mass of plant-derived components was obtained.
The obtained antibacterial resin composition (kneaded material) was uniformly pulverized and packed in a mold, and molded using a press molding machine at 1 MPa, 180 ° C. for 10 minutes. Then, it heated for 2 hours in 180 degreeC oven, and obtained the molded object (hardened | cured material).

(Appearance evaluation and antibacterial test)
As a result of evaluating the appearance of the molded article (cured product of the antibacterial resin composition) in the same manner as in Reference Example 1 , it was judged as ◎. Moreover, as a result of conducting an antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 3.8 and 2.6 for Escherichia coli and Staphylococcus aureus, respectively.

(Reference Example 4 )
(Molding of antibacterial resin composition)
An antibacterial resin composition was obtained in the same manner as in Reference Example 3 except that the lignin described in Reference Example 2 was used and the amount of lignin added was 0.41 g. An antibacterial resin composition containing 0.1% by mass of lignin and 57% by mass of plant-derived components was obtained.

(Molding and appearance evaluation of antibacterial resin composition, antibacterial test)
As a result of evaluating the appearance of the molded article (cured product of the antibacterial resin composition) in the same manner as in Reference Example 1 , it was judged as ◎. Moreover, as a result of conducting an antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 6.1 and 4.7 for Escherichia coli and Staphylococcus aureus, respectively.

(Reference Example 5 )
Except for adding 0.34 g of lignin described in Reference Example 1 and using 156 g of epoxy resin (YDF-8170C, manufactured by Nippon Steel Chemical Co., Ltd.), which is a thermosetting resin derived from petroleum, instead of epoxidized soybean oil. In the same manner as in Reference Example 3 , an antibacterial resin composition was obtained. The obtained antibacterial resin composition contained 0.1% by mass of lignin, and the plant-derived component ratio was 0.1% by mass. As a result of evaluating the appearance of the molded article (cured product of the antibacterial resin composition) in the same manner as in Reference Example 1 , it was judged as ◎. Moreover, as a result of conducting an antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 6.0 and 4.8 for Escherichia coli and Staphylococcus aureus, respectively.

(Reference Example 6 )
Other than adding 3.4 g of lignin described in Reference Example 1 and using 156 g of an epoxy resin (YDF-8170C, manufactured by Nippon Steel Chemical Co., Ltd.) which is a thermosetting resin derived from petroleum instead of epoxidized soybean oil. In the same manner as in Reference Example 3 , an antibacterial resin composition was obtained. The obtained antibacterial resin composition contained 1% by mass of lignin, and the plant-derived component ratio was 1% by mass. As a result of evaluating the appearance of the molded article (cured product of the antibacterial resin composition) in the same manner as in Reference Example 1 , it was judged as ◎. In addition, as a result of performing the antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 6.2 and 4.8 for E. coli and S. aureus, respectively, and were judged to have antibacterial properties.

(Reference Example 7 )
Except for adding 375 g of lignin described in Reference Example 1 and using 200 g of an epoxy resin (YDCN-701, manufactured by Nippon Steel Chemical Co., Ltd.), which is a thermosetting resin derived from petroleum, instead of epoxidized soybean oil. An antibacterial resin composition was obtained in the same manner as in Example 3 . The obtained antibacterial resin composition contained 50% by mass of lignin, and the plant-derived component ratio was 50% by mass. As a result of evaluating the appearance of the molded body (cured product of the antibacterial resin composition) in the same manner as in Reference Example 1 , it was judged as ◯. Moreover, as a result of performing an antibacterial test similarly to Reference Example 1 , the antibacterial activity values were 6.7 and 5.4 for Escherichia coli and Staphylococcus aureus, respectively.

(Comparative Example 6)
A resin composition was obtained in the same manner as in Reference Example 3 except that 0.038 g of lignin described in Reference Example 1 was added. The obtained resin composition contained 0.009% by mass of lignin, and the plant-derived component ratio was 57% by mass. As a result of evaluating the appearance of the molded body (cured product of the resin composition) in the same manner as in Reference Example 1 , it was judged as ◎. Moreover, as a result of performing the antibacterial test similarly to the reference example 1 , the antibacterial activity value was 1.9 and 1.7 with respect to Escherichia coli and Staphylococcus aureus, respectively, and it was determined that there was no antibacterial property.

(Comparative Example 7)
A resin composition was obtained in the same manner as in Reference Example 3 except that 0.021 g of lignin described in Reference Example 1 was added and 230 g of polyethylene (PE) was used instead of epoxidized soybean oil. The obtained resin composition contained 0.009% by mass of lignin, and the plant-derived component ratio was 0.009% by mass. As a result of evaluating the appearance of the molded body in the same manner as in Reference Example 1 , it was judged as ◎. Moreover, as a result of conducting an antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 1.8 and 1.7 for Escherichia coli and Staphylococcus aureus, respectively.

(Comparative Example 8)
A resin composition was obtained in the same manner as in Reference Example 3 , except that 250 g of lignin described in Reference Example 1 was added and 230 g of polypropylene (PP) was used instead of epoxidized soybean oil. The obtained resin composition contained 52% by mass of lignin and had a plant-derived component ratio of 52% by mass. As a result of evaluating the appearance of the molded body (cured product of the resin composition) in the same manner as in Reference Example 1 , the result was x. Moreover, as a result of conducting an antibacterial test in the same manner as in Reference Example 1 , the antibacterial activity values were 6.6 and 6.5 for Escherichia coli and Staphylococcus aureus, respectively.

Claims (2)

An antibacterial resin composition containing lignin and a thermoplastic resin, wherein the lignin is a separation technique using water, crushing plants by hydrolysis and physical crushing, washing with water, and water-soluble It is a lignin obtained by removing components, separating from cellulose components and hemicellulose components, and dissolving them in an organic solvent, having a weight average molecular weight of 100 to 7000 and a sulfur atom content of 0.5% by mass or less. Yes, lignin is soluble in an organic solvent, and the solvent solubility of acetone, cyclohexanone, tetrahydrofuran, ethylene glycol, and N-methyl-2-2, when 5 g of lignin is dissolved in 95 ml of solvent. It dissolves at 25 ° C. in pyrrolidone, and dissolves at 50-70 ° C. in methanol, ethanol and methyl ethyl ketone, Thermoplastic resins, port Riechiren are those selected from and polypropylene, antibacterial resin composition which comprises 0.01 to 50% by weight of lignin as a non-volatile content. The molded object obtained using the antibacterial resin composition of Claim 1.