JP5456390B2 - Antibacterial resin composition - Google Patents

Description

  The present invention relates to a resin composition having antibacterial performance.

Conventionally, a method for imparting antibacterial properties to a resin composition is, for example, a method in which an antibacterial agent composed of metal or metal oxide particles is used as a plastic material and molded into a film or sheet-like plastic containing the antibacterial agent. It has been proposed (see, for example, Patent Document 1).
In addition, a resin composition using a phosphate glass containing one or more metal ions having antibacterial properties such as silver, copper, zinc, tin, or a boron oxide glass containing metal ions has been proposed (for example, , See Patent Document 2).
Furthermore, a multilayer plastic container using an organic antibacterial agent has been proposed (for example, see Patent Document 3).

JP 2005-132866 A JP 2006-213796 A Japanese Patent Laid-Open No. 11-236037

  In the above-described method, although antibacterial performance can be imparted, in general, the antibacterial agent itself has a certain toxicity, and has a safety problem. An object of this invention is to provide a highly safe antibacterial resin composition.

As a result of intensive investigations on safe antibacterial agents, the present inventors have conventionally used highly safe materials such as foods and food additives used in the food field, and polylactic acid in resin compositions. The above problems were solved by using bioplastics such as
That is, the present invention relates to an antibacterial resin composition characterized by containing a food and a food additive as an antibacterial agent, a method for producing these antibacterial resin compositions, and a method for preserving foods using them. .

By using a highly safe antibacterial agent for resin compositions used as food containers, food films, etc., the commercial value can be significantly improved.
In addition, in the case of bioplastics obtained from plant-derived raw materials such as polylactic acid, the plant resistance of bioplastics is not reduced by using plant-derived antibacterial agents such as glycerin fatty acid esters and tea extracts as antibacterial agents. Has an effect.

  In the present invention, the resin composition is desirably a thermoplastic resin or a thermosetting resin, but is not limited thereto. The resin composition is preferably a bioplastic in consideration of environmental load, but is not limited thereto. The resin may be one type or a mixture of two or more types.

  Specific examples of biodegradable plastics include polybutylene succinate (PBS), poly (butylene succinate / adipate) (PBSA), poly (butylene succinate / carbonate) (PEC), poly (ethylene). Terephthalate / succinate) (PETS), poly (butylene adipate / terephthalate) (PBAT), poly (tetramethylene adipate / terephthalate) (PTMAT), polyethylene succinate (PES), polyvinyl alcohol (PVA), polyglycolic acid (PGA) ), Polylactic acid (PLA), (polylactic acid / polybutylene succinate system) block copolymer (PLA-co-PHB), polycaprolactone (PCL), poly (caprolactone / butylene succinate) (PCLBS), polyhydroxy Examples include biomass-derived resins such as acid (PHB), poly (hydroxybutyrate / hydroxyhexanoate) (PHBH), polyhydroxyalkanoate (PHA), carbodiimide compounds, cellulose acetate, starch resin, and derivatives thereof. Can do. These can be used alone or in combination of two or more. Of these, polybutylene succinate (PBS) and polycaprolactone (PCL) are particularly preferable in terms of strength improvement. By using these biomass-derived resins, the effect of greatly reducing the environmental load can be obtained.

  Here, the biomass-derived resin refers to a resin containing as a main component a resin made from biomass as a raw material, and these derivatives are substituted or modified in part of the molecular structure with other compounds or functional groups. It means what was done.

  The biodegradable organic compound preferably has a weight average molecular weight of 4000 to 70000, more preferably 10,000 to 30000. If the weight average molecular weight is 4,000 or more, the effect of surface modification is obtained and the wettability with the matrix resin is sufficient. Moreover, if a weight average molecular weight is 70000 or less, it can suppress that the cohesion force of biodegradable organic compounds increases, and can suppress that a dispersibility falls. It is preferable that it is 4000-10000 since the adhesiveness of the interface between fibrous fillers and between matrix resins can be improved and an improvement in intensity | strength can be aimed at.

  It is preferable that the said biodegradable organic compound is couple | bonded in the range of 10-50 mass% with respect to a fibrous filler, More preferably, it is 30-40 mass%. If the binding amount of the biodegradable organic compound is 10% by mass or more, the wettability of the fibrous filler to the matrix resin is sufficient, and if it is 50% by mass or less, the aggregation of the fibrous filler is suppressed and the matrix is suppressed. It becomes easy to uniformly disperse the resin.

  The biodegradable organic compound and the fibrous filler are preferably contained in an amount of 0.5% by mass or more and 30% by mass or less, more preferably 1 to 15% by mass with respect to the total amount of the resin composition. If the content of the biodegradable organic compound and the fibrous filler is 0.5% by mass or more, a mechanical strength effect can be obtained in the resin molded body, and if it is 30% by mass or less, the fibrous filler It becomes easy to suppress aggregation and uniformly disperse in the matrix resin, and a reinforcing effect can be obtained in the resin molded body.

  The matrix resin used in the reinforced resin composition of the present invention may be a thermoplastic resin, thermosetting, a mixture or alloy thereof, and a general-purpose resin in the resin molding field can be applied.

  Specific examples of the thermoplastic resin include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), and liquid crystal polyester (LCP). Polyolefins such as polyethylene (PE), polypropylene (PP), polybutene 1 (PB-1), polybutylene, styrene resins, polyoxymethylene (POM), polyamide (PA), polycarbonate (PC), polymethylene methacrylate (PMMA), polyvinyl chloride (PVC), polyphenylene ether (PPE), polyphenylene sulfide (PPS), polyimide (PI), polyamideimide (PAI), polyetherimide (PEI), polysulfone (PSU), polyether sulfone, polyketone (PK), polyether ketone (PEK), polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polyarylate (PAR), polyether nitrile (PEN), phenol (Novolac type and the like) Fluorine resins such as phenoxy resin, polytetrafluoroethylene (PTFE), copolymers thereof, modified products, or resins obtained by blending two or more types may be used.

  The thermoplastic resin mentioned above can select and use a specific thing according to the characteristic requested | required of the molded object shape | molded using the reinforced resin composition of this invention. Specifically, for example, a polyester resin is not only excellent in practical properties such as heat resistance, friction resistance, chemical resistance, and workability, but also blended with various fillers and other resins. It has characteristics that it is easy, and is suitable as a matrix resin for a molded product that requires these characteristics.

  Furthermore, as biodegradable plastics, polylactic acid (PLA), polybutylene succinate (PBS), polycaprolactone (PCL), polyhydroxybutyric acid (PHB), polyhydroxyalkanoate (PHA), cellulose acetate, starch resin, etc. Biomass-derived resins and derivatives thereof are preferred as matrix resins because they have the characteristics that they can be decomposed by microorganisms and greatly reduce the environmental burden. In particular, polylactic acid is preferable from the viewpoint of strength improvement. These polyester resins can be arbitrarily mixed with other thermoplastic resins.

  Specific examples of the thermosetting resin include unsaturated polyesters, vinyl esters, epoxies, phenols (resol type), urea melamines, polyimides, copolymers thereof, modified products, or two types. The blended resin can be used.

  Moreover, an elastomer and rubber | gum can be used with the said resin for impact resistance improvement. Elastomers such as EPR and EPDM, styrene elastomers such as SBR made of a copolymer of styrene and butadiene, silicone elastomers, nitrile elastomers, butadiene elastomers, urethane elastomers, nylon elastomers, Examples thereof include ester-based elastomers, fluorine-based elastomers, natural rubber, and modified products in which reaction sites (double bonds, anhydrous carboxyl groups, etc.) are introduced into these elastomers.

  In the present invention, the resin composition is applied not only to normal resin molding such as injection molding, extrusion molding, blow molding, and sheet molding, but also to higher melt molding such as fiberization by spinning and film formation by film formation. Is possible.

In the present invention, the antibacterial agent is not particularly limited as long as it is an antibacterial agent used in the food field, but if specifically mentioned, an organic acid, an organic acid salt (especially mainly sodium acetate) , Amino acid, phosphate, glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, polysorbate, benzoic acid and / or its salt, sorbic acid and / or its salt, sodium dehydroacetate, paraoxybenzoic acid Isobutyl, isopropyl paraoxybenzoate, ethyl paraoxybenzoate, butyl paraoxybenzoate, propyl paraoxybenzoate, propionic acid and / or its salt, sodium sulfite, sodium hyposulfite, sulfur dioxide, pyrosulfite, tea extract, udo extraction Food, Egony extract, Mosquito Ray mugwort extract, enzymatically decomposed pearl barley extract, shirako protein extract, tsuyaprisin, pectin degradation product, honoki extract, ε-polylysine, natamycin, melanoidin, allyl isothiocyanate, hinokitiol, agar oligosaccharide, tea tannin, betaine, Chitin chitosan, chitosan degradation product, red yeast rice degradation product, pectin degradation product, bearfish ingredient, citrus seed extract, perilla extract, grapefruit seed extract, rosemary extract, oyster mushroom extract, strawberries extract, Mace extract, nutmeg extract, ferulic acid, forsythia extract, glycine, leucine, isoleucine, nisin, gassericin A, alanine, serine, phenylalanine, tryptophan, threonine, sorghum peel pigment, acetic acid and / or salt thereof, thiamine lauryl sulfate Salt and fig leaf Extract, oregano extract, mustard extract, licorice oily extract, chitosan, clove extract, mulberry extract, enzyme-treated tea extract, enzymatically decomposed apple extract, saponin extract, perilla extract, ginger extract, Horseradish extract, Sage extract, Tade extract, Pepper aqueous extract, Raw soybean extract, Garlic extract, Bee extract, Pimenta extract, Grape peel extract, Grape seed extract, Propolis extract, Pepper Extract, squeeze extract, mushroom extract, mandarin seed extract, moso bamboo dry extract, moso bamboo extract, peach extract, yucca foam extract, licorice extract, hop extract, yucca extract, tamarind extract, etc. Plant extract extract, spice extract, lysozyme, lactoferrin, lactoferricin, protamine, bacteria Antibacterial agents such as syn, lactoperoxidase, glucose oxidase, catalase, isothiocyanate compound, rosemary extract, horseradish extract, orthophosphoric acid and / or salt thereof, polymerized phosphate, carbonate, phytic acid, itaconic acid , Α-ketoglutaric acid, ferulic acid, vitamins (mainly vitamin C, vitamin B ₁ ), egg white peptide, ethanol, and other antibacterial components, and one or more of these can be used.

The antibacterial agents listed above are preferably glycerin fatty acid esters, sucrose fatty acid esters, and tea extracts from the viewpoint of antibacterial properties.
In addition, the glycerin fatty acid ester of the antibacterial agent listed above includes, but is not limited to, polyglycerin fatty acid ester, organic acid monoglyceride, etc., but glycerin medium chain fatty acid ester, polyglycerin medium chain fatty acid ester, Furthermore, medium chain fatty acid monoglycerides are desirable.

  The glycerin medium chain fatty acid ester is an ester of glycerin and a medium chain fatty acid, and the medium chain fatty acid is not particularly limited, but caprylic acid, capric acid, and lauric acid having 8 to 12 carbon atoms are preferable. Examples of glycerin medium chain fatty acid esters include mono-, di-, and triesters, and examples thereof include glycerin monocaprylate, glycerin monocaprate, and glycerin monolaurate. The glycerin medium chain fatty acid ester used in the present invention is preferably one having a monoester content of 40% or more, more preferably one having a monoester content of 80% or more from the viewpoint of antibacterial activity. The monoester content referred to in the present invention refers to a monoester in the glycerin fatty acid ester.

  It is desirable that the antibacterial agent of the antibacterial resin composition has a release property depending on the application. Furthermore, it is desirable to adjust the sustained release rate of the antibacterial agent according to the application. In the case where the antibacterial resin composition is a food packaging container for short-term distribution or short-term use such as lunch box, side dish, sandwich, etc., the antibacterial effect can be improved by increasing the release rate.

On the other hand, in the case of a resin composition that is used for a long period of time, such as household goods, the effect can be maintained over a long period of time by slowing the dividing rate.
The release property of the antibacterial agent can be freely adjusted depending on the combination of the resin and the antibacterial agent used, and is not particularly limited.

  Among the antibacterial agents listed above, those that can be expected to be effective as a resin composition modifier such as glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, and polysorbate are desirable. .

  Among the antibacterial agents listed above, those that can be expected to be effective as a deodorant in addition to antibacterial properties such as tea extract are desirable.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

Example 1. Film preparation by cast film method (Invention product 1)
10 parts of polylactic acid, 0.1 part of an antibacterial agent, and 10 parts of chloroform were stirred and stirred in a beaker for 3 hours, and the whole was poured into a circular petri dish and dried at 50 ° C. for 24 hours. ) Containing petri dishes were prepared. As an antibacterial agent, glycerin monocaprylate (Sunsoft No. 700P-2 manufactured by Taiyo Kagaku Co., Ltd.) was used.

Example 2 Film preparation by cast film method (Invention product 2)
A petri dish containing a film (product 2 of the present invention) was prepared in the same manner as in Example 1 except that the tea extract (Sanphenon 100S manufactured by Taiyo Kagaku Co., Ltd.) was used as the antibacterial agent.

Example 3 Film preparation by cast film method (Invention product 3)
A petri dish containing a film (Product 3 of the present invention) was prepared in the same manner as in Example 1 except that the tea extract (Sunphenon EGCg manufactured by Taiyo Kagaku Co., Ltd.) was used as the antibacterial agent.

Comparative Example 1 Film preparation by the cast film method (Comparative product 1)
As a comparative example, a petri dish containing a film (comparative product 1) was prepared in the same manner as in Example 1 except that no antibacterial agent was blended.

Test example 1
225 g of weak flour, 75 g of strong flour, 15 g of sugar, 5 g of dry yeast, 20 g of refined lard, and 180 g of milk were mixed in a cake mixer for 8 minutes, and this was subjected to primary fermentation at 37 ° C. for 30 minutes. And steamed on high heat for 10 minutes to prepare steamed steamed rice.

  The prepared steamed bun was cut equally, the steamed pieces were put into the petri dishes with the films prepared in Examples 1 to 3 and Comparative Example 1, sealed and stored at 25 ° C., and the number of days on which mold was generated was checked. The results are shown in Table 1.

  As apparent from Table 1, mold was generated in 3 days in the comparative product 1, but mold was not generated in the product of the present invention for 5 to 6 days.

Test example 2
The bacteriostatic effect in the culture medium was observed using the following strains.
Bacillus cereus
Escherichia coli
Staphylococcus aureus (staphylococci)
A commercially available medium (dried broth) was prepared in a test tube and pasteurized with high-pressure steam, and the above-mentioned strain was inoculated into one platinum ear and cultured at 30 ° C. for 4 days to prepare a preculture solution. A petri dish containing a film was prepared in the same manner as in Test Example 1, and 0.5 g of the preculture solution prepared previously was uniformly applied thereto, and cultured at 30 ° C. for 1 day to observe the growth of the bacteria. The results are shown in Table 2.

◎: No colony generation ○: Slight colony generation ×: Colony generation recognized

  As is clear from Table 2, in all of the strains in Comparative Product 1, colonies were observed, but in the products of the present invention, there were no colonies or only a few colonies were observed.

  According to the present invention, it is possible to provide a highly safe antibacterial resin composition (a packaging container, sheet or film for foods), which contributes greatly to the industry.

Claims (2)

  Antibacterial polylactic acid characterized in that it is a medium-chain fatty acid monoglyceride having a monoester content of 80% or more as an antibacterial agent, and the fatty acid is one or more selected from the group of caprylic acid, capric acid and lauric acid Resin composition.   The antimicrobial polylactic acid resin composition according to claim 1, wherein the medium chain fatty acid monoglyceride is caprylic acid monoglyceride.