JP3070033B2 - Antibacterial film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial film comprising a water-swellable polyurethane resin layer containing a powder of an inclusion compound in which an isothiocyanate is included in cyclodextrin, and a container wrapped with a wrap or the like. The present invention relates to an antibacterial film that is laid or covered between foods and has an antibacterial effect of preventing the occurrence of mold, bacteria, and the like in foods.

[0002]

2. Description of the Related Art Conventionally, as an antibacterial film and a method for producing the same, an isothiocyanate compound or a terpene compound or a compound thereof is included in a synthetic resin film in which a clathrate compound is dispersed and contained in a cyclodextrin. (For example, JP-A-6-191562), an antibacterial film having an adhesive layer in which powder of an inclusion compound in which allyl isothiocyanate is included in cyclodextrin is dispersed in an adhesive for lamination (for example, JP-A-6-92602).
No. 842) is known.

[0003]

However, in both of the above and the above, since the inclusion compound in which allyl isothiocyanate is included in cyclodextrin is incorporated in the film or the adhesive layer, the drip exuding from the food and the inclusion are included. There has been a problem that the contact with the compound is delayed and the antibacterial effect of the food packaged in the container is reduced.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that water swelling is obtained by mixing and dispersing the clathrate powder in a hydrophilic polyurethane prepolymer containing terminal isocyanate groups. By laying or covering an antibacterial film composed of a water-soluble polyurethane resin layer between a container wrapped with wrap or the like and the food, drip oozing from the food quickly penetrates the water-swellable polyurethane resin layer, It has been found that the antibacterial gas is released slowly upon contact with the clathrate compound and the antibacterial gas is immediately released, and the present invention has been found.

That is, the present invention comprises a water-swellable polyurethane resin layer (A) containing a powder of an inclusion compound in which an isothiocyanate ester is included in cyclodextrin, wherein the (A) comprises isothiocyanate ester in cyclodextrin. An antibacterial film, which is obtained by mixing and dispersing a clathrate powder containing a clathrate compound contained in a hydrophilic polyurethane prepolymer (1) having terminal isocyanate groups with water and curing the mixture; and isothiocyanate ester. It comprises a water-swellable polyurethane resin layer (A) containing an inclusion compound powder encapsulated with cyclodextrin, and (A) is used to convert the inclusion compound powder containing isothiocyanate ester into cyclodextrin with terminal isocyanate. Group-containing hydrophilic polyurethane prepolymer (1) and polyether poly An antibacterial film, characterized in that is obtained by curing those mixed dispersed allowed to Lumpur (2).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The isothiocyanate in the present invention includes allyl isothiocyanate, isoamyl isothiocyanate, isobutyl isothiocyanate, isopropyl isothiocyanate, ethyl isothiocyanate, nitrophenyl isothiocyanate, phenyl isothiocyanate, butyl isothiocyanate and isothiocyanate. Propyl acid, benzyl isothiocyanate, methyl isothiocyanate, and the like; and a mixture of two or more thereof. Among these, preferred is allyl isothiocyanate.

In order to exhibit the antibacterial effect of the present invention, it is desirable that the particle diameter of the clathrate compound powder in which the isothiocyanate is included with cyclodextrin is small, usually 50 μm or less, preferably 30 μm or less.

The water-swellable polyurethane resin layer is obtained by mixing and dispersing a powder of an inclusion compound in which an isothiocyanate ester is included with cyclodextrin in a hydrophilic polyurethane prepolymer having an isocyanate group at the end, and then moisture-curing; And a mixture obtained by mixing and dispersing an inclusion compound powder in which an isothiocyanate ester is included with cyclodextrin in a hydrophilic polyurethane prepolymer having terminal isocyanate groups and a polyether polyol, and curing the mixture.

[0009] The water absorption capacity of the water-swellable polyurethane resin is usually 10% or more, preferably 50% or more, particularly preferably 100% or more, from the viewpoint of the sustained release rate of the antibacterial gas. The water absorption capacity (%) is a value calculated by the following equation, where the weight before water immersion is (W1) and the weight after water immersion is (W2). Water absorption capacity (%) = (W2−W1) × 100 / W1

The polyisoanates constituting the hydrophilic polyurethane prepolymer (1) having a terminal isocyanate group in the present invention include aromatic diisocyanates, aliphatic diisocyanates and alicyclic diisocyanates, and tolylene diisocyanate (TDI) ), Α, α, α ', α'-tetramethylxylylene diisocyanate (TMXDI), diphenylmethane diisocyanate (MDI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI), etc .; (HDI), trimethylhexamethylene diisocyanate (TMDI), lysine diisocyanate (LDI), etc .; B hexyl methane diisocyanate (HMDI), isophorone diisocyanate (IPD
I), 1,4-cyclohexane diisocyanate (CH
DI), hydrogenated xylene diisocyanate (HXDI),
And hydrogenated tolylene diisocyanate (HTDI); and a mixture of two or more thereof. Preferred of these are TDI, MDI, HMDI and IP
DI, particularly preferred are TDI and MDI.

As the other polyisocyanate, a modified product of the above-mentioned aromatic, aliphatic or alicyclic polyisocyanate compound can be used. As a modified product of the polyisocyanate compound, a compound in which a part or all of the isocyanate groups of the compounds exemplified above are modified into a carbodiimide group, a uretdione group, a uretoimine group, a buret group, an isocyanurate group, and two or more kinds of these compounds And mixtures thereof. Of these, preferred is TD
I, carbodiimide-modified and isocyanurate-modified polyisocyanates derived from MDI.

The polyether polyol (2) constituting (1) includes low molecular weight polyols [ethylene glycol, propylene glycol, 1,4-butanediol,
Bisphenol A, glycerin, trimethylolpropane, etc.] as a starting material, and addition polymerization or addition copolymerization of an alkylene oxide (alkylene oxide having 2 to 4 carbon atoms; ethylene oxide, propylene oxide, 1,2-butylene oxide, tetrahydrofuran, etc.) ( (Block and / or random). Preferred oxyalkylenes are oxyethylene alone or oxyethylene / oxypropylene mixtures. 2
In the case of an addition copolymer of two or more oxyalkylenes, the oxyethylene content based on the weight of all oxyalkylenes is usually 30% or more, and preferably 50% or more, from the viewpoint of imparting hydrophilicity.

The hydroxyl equivalent of the polyether polyol (2) constituting (1) is 20 due to the flexibility of the antibacterial film.
0 to 3000 is preferred.

(1) is obtained by reacting the polyisocyanate with the polyether polyol. The NCO / OH equivalent ratio of the reaction is usually (1.2 to 3) / 1, preferably (1.5 to 2) / 1. The prepolymerization reaction is carried out without solvent or under dilution with an organic solvent (ethyl acetate, MEK, toluene, xylene, etc.), and the reaction temperature is usually 50 to 150 ° C, preferably 60 to 100 ° C. In the reaction, a known organic metal catalyst (dibutyltin dilaurate, lead stearate, etc.) can be added to accelerate the reaction. The NCO% of (1) is usually 0.3 to 10%, preferably 0.5 to 7% from the viewpoint of the physical properties of the antibacterial film.

When the water-swellable polyurethane resin is obtained by curing (1) and (2), the equivalent ratio (NCO / OH) of the isocyanate group in (1) to the hydroxyl group in (2) is usually 1 /(0.5 to 2), preferably 1 / (0.9 to
1.2). If necessary, a known organic metal catalyst (dibutyltin dilaurate, lead stearin, etc.) can be added.

The antimicrobial film of the present invention may be composed of the water-swellable polyurethane resin layer (A) alone containing the clathrate compound powder in which the isothiocyanate is included in cyclodextrin, but may have a through-hole. A form having (A) on a resin film or sheet (B) or a nonwoven fabric made of synthetic resin and / or natural pulp (C), or (A) interposed between (B) and (C) Is preferred.

The method for producing the resin layer (A) is as follows.
(1) or H (1), a polyether polyol and a powder of the clathrate are mixed and dispersed. The ratio is 100 (resin content) / (5-80), preferably 1 based on weight.
00 (resin content) / (10-50), and if necessary, an organic solvent (ethyl acetate, MEK, toluene, xylene, etc.)
Can be diluted with. It is obtained by casting the mixed dispersion on a release sheet held horizontally so as to have a thickness of 0.5 to 3 mm (after curing) and curing at 45 ° C. overnight.

As the synthetic resin film or sheet (B) having a through hole, a material conventionally used for packaging and other widely used materials is used, and specific examples thereof include PET (polyethylene terephthalate), polyamide, and KPET.
(Vinylidene chloride-coated polyester), KYN (vinylidene chloride-coated nylon), KOP (vinylidene chloride-coated stretched polypropylene), PE (polyethylene),
CPP (unstretched polypropylene), EVA (ethylene-
Vinyl acetate copolymer) and the like.

Although the thickness of the film is not particularly limited, it is preferably, for example, in the range of several μm to several tens μm. Further, the diameter of the through-holes and the number of the through-holes are determined by the amount of drip oozing from the food and the inclusion compound. Should be set in consideration of the degree of sustained release (time or number of days from food preservation to consumption of food). In case of enhancing sustained release (decrease in antibacterial gas release rate from the inclusion compound In this case, the diameter of the through-hole may be reduced or the number of through-holes may be reduced.

Examples of the nonwoven fabric made of the synthetic resin (C) include PET (polyethylene terephthalate), polyester and the like. Although the thickness is not particularly limited, for example, a range of several μm to several tens μm is preferable. As the natural pulp, materials used for packaging and other widely used materials are used.

In the case where (A) is in the form having (B) or (C), or in the case where (A) is interposed between (B) and (C), the manufacturing method is as follows. The mixed dispersion is usually applied to one side of a synthetic resin film having through-holes in a thickness of 3 to 30 μm (after drying), preferably 5 to 20 μm.
(After drying) and then 45 ° C
An antibacterial film can also be produced by a method of curing overnight, or a method of laminating a nonwoven fabric or a natural pulp made of a synthetic resin on the coated surface and then curing it at 45 ° C. for one day.

The antibacterial film of the present invention is cut into a desired size and spread between a container and food to be wrapped with a wrap or the like to exhibit an antibacterial effect. In general, these foods take about 8 hours from the time of food processing and packaging until they are consumed by the consumer, and an antibacterial film which sufficiently exhibits an antibacterial effect within this time is required. The antimicrobial film of the above satisfies these requirements.

[0023]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. In the following, "parts" indicates parts by weight and "%" indicates% by weight.

Production Example 1 [Production of hydrophilic polyurethane prepolymer] A 1-liter volume 4 equipped with a stirrer, thermometer and nitrogen inlet tube was prepared.
484 parts of polyether polyol "SANNIX FA-103" (manufactured by Sanyo Chemical Industries, molecular weight 3300, oxyethylene content 70% based on the weight of all oxyalkylenes) and "Coronate T-80" (Nippon Polyurethane) Industrial, 2,4- and 2,6-tolylene diisocyanate (80/20) mixture, NCO content 48
%) 76 parts, ethyl acetate 240 parts and dibutyltin dilaurate 1 part were charged and reacted at 80 ° C. for 5 hours under a nitrogen stream, NCO content 2.2%, viscosity 1500 cp / 25 ° C.
To obtain 800 parts of a hydrophilic polyurethane prepolymer.

Production Example 2 [Production of hydrophilic polyurethane prepolymer] Using the same reactor as in Production Example 1, polyether polyol "Newpol 80-4000" (manufactured by Sanyo Chemical Industries, molecular weight 4000, all oxyalkylene) 498 parts of oxyethylene content (80% based on weight)
I "(manufactured by Nippon Polyurethane Industry, NCO content 33%) 6
2 parts, 240 parts of ethyl acetate and 1 part of dibutyltin dilaurate were charged, and reacted at 80 ° C. for 5 hours under a nitrogen stream.
800 parts of a hydrophilic polyurethane prepolymer having an NCO content of 1.3% and a viscosity of 1000 cp / 25 ° C. was obtained.

Production Example 3 [Production of Non-Hydrophilic Polyurethane Prepolymer] Using the same reactor as in Production Example 1, a polyether polyol "Sannicks Triol GP-3000" (manufactured by Sanyo Chemical Industries, molecular weight 3000, total oxy 286 parts of oxyethylene content (0% based on the weight of alkylene)
191 parts of "SANNIX Diol PP-2000" (manufactured by Sanyo Chemical Industries, molecular weight 2000, oxyethylene content 0% based on the weight of all oxyalkylenes), "Coronate T-80" (manufactured by Nippon Polyurethane Industry, 2, 4-
And 2,6-tolylene diisocyanate (80/20)
Mixture, NCO content 48%) 83 parts, ethyl acetate 240
And 1 part of dibutyltin dilaurate were charged and reacted at 80 ° C. for 5 hours under a nitrogen stream to obtain 800 parts of a non-hydrophilic polyurethane prepolymer having an NCO content of 2.4% and a viscosity of 1200 cp / 25 ° C.

Example 1 100 parts of the hydrophilic polyurethane prepolymer produced in Production Example 1 and 50 parts of a clathrate compound powder obtained by enclosing allyl isothiocyanate having a particle size of 25 μm with cyclodextrin were mixed using a usual dispersing apparatus. Dispersed. This mixed dispersion was cast on a release sheet held horizontally so as to have a thickness of 1 mm (after curing and drying), and cured at 45 ° C. overnight to produce an antibacterial film. Table 1 shows the performance evaluation results.

Example 2 Antibacterial activity was the same as in Example 1 except that the hydrophilic polyurethane prepolymer obtained in Production Example 2 was used in the same amount instead of 100 parts of the hydrophilic polyurethane prepolymer produced in Production Example 1. A film was produced. Table 1 shows the performance evaluation results.

Example 3 100 parts of the hydrophilic polyurethane prepolymer prepared in Preparation Example 1 was mixed with a polyether polyol "Newpole GE".
P2800 "(manufactured by Sanyo Chemical Industries, molecular weight 2500, oxyethylene content 48% based on the weight of all oxyalkylenes) 40 parts, dibutyltin dilaurate 0.1 parts, allyl isothiocyanate having a particle size of 25 µm are included with cyclodextrin. 50 parts of the clathrate compound powder thus obtained was mixed and dispersed by using an ordinary dispersing apparatus. This mixed dispersion was cast on a release sheet held horizontally so as to have a thickness of 1 mm (after curing and drying), and cured at 60 ° C. overnight to produce an antibacterial film. Table 1 shows the performance evaluation results.

Example 4 100 parts of the hydrophilic polyurethane prepolymer prepared in Preparation Example 2, 50 parts of a clathrate compound powder obtained by enclosing allyl isothiocyanate having a particle size of 25 μm with cyclodextrin, and 110 parts of ethyl acetate were dispersed in a usual manner. The mixture was dispersed using an apparatus. This mixed dispersion is passed through a through-hole (pore diameter: 0.8 m
m, the number of holes; 80 holes / 50 mm × 50 mm)
One side of the film (thickness: 20 μm) was coated so that the thickness after drying was 10 to 15 μm. Further, a polyester non-woven fabric (flexible type, thickness: 0.2 mm) was bonded to the coated surface and cured at 45 ° C. overnight to produce a laminated antibacterial film. Table 1 shows the performance evaluation results.

Comparative Example 1 The procedure of Example 1 was repeated, except that the same amount of the non-hydrophilic polyurethane prepolymer obtained in Production Example 3 was used instead of 100 parts of the hydrophilic polyurethane prepolymer produced in Production Example 1. Similarly, an antibacterial film was produced. Table 1 shows the performance evaluation results.

The performance evaluation items and evaluation methods in Table 1 are as follows. Water absorption capacity (%) of antibacterial film; antibacterial films obtained in Examples 1 to 4 and Comparative Example 1 were each 30 mm ×
It was cut into a size of 30 mm and the weight (W1) was weighed.
Each cut film was immersed in water at a water temperature of 5 ° C. and 25 ° C., and the weight (W2) of the sheet 5 hours after immersion was weighed. Water absorption capacity (%) of antibacterial film = (W2-W1) x
100 / W1. Measurement of antimicrobial gas amount: Each of the antimicrobial films produced in Examples 1 to 4 and Comparative Example 1 was cut into a size of 50 mm × 150 mm. The above-mentioned antibacterial film (the state of the synthetic resin film having a through-hole facing up) was placed in a closed container provided with a gas sampling port, and the entire container was placed in a test chamber at 5 ° C. The upper lid of the closed container was removed, and approximately 3 to 5 g of water was uniformly sprayed on the antibacterial film using a water sprayer, and then the container was immediately closed. Samples were taken from the gas sampling port of the container at regular intervals after water spraying, and the amount of antibacterial sustained release gas was determined by gas chromatography. Explanation of symbols ×; <1 ppm, Δ: 1 to 10 ppm, ；: 10 to 50
ppm, ◎;> 50 ppm

[0033]

[Table 1] Water absorption capacity, sustained release of antibacterial gas after water spray (elapsed time)

[0034]

The antimicrobial film of the present invention has the following effects. (1) The conventional antibacterial film contains a powder of an inclusion compound in which isothiocyanate is included in cyclodextrin, which is dispersed and contained in the synthetic film. Limited. The antibacterial film of the present invention can quickly generate an antibacterial gas when it comes into contact with a drip oozing out of food, and can prevent mold of food (such as fish sashimi) packaged in a container that is consumed in a relatively short time. And antibacterial effects such as suppression of bacterial growth. (2) The antibacterial film having such characteristics is also useful for base materials such as antibacterial bandages and bed antibacterial sheets in the healthcare field.

Continuation of the front page (72) Inventor Toshiro Shimada 11-11 Hitotsubashi Nohonmachi, Higashiyama-ku, Kyoto Sanyo Chemical Industry Co., Ltd. (56) References JP-A-51-36295 (JP, A) JP-A-61-83216 (JP, A) Japanese Utility Model Application Hei 3-111982 (JP, U) Japanese Utility Model Application Hei 3-126489 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A23B 4/00 A23L 3 / 3535 C08G 18/00-18/87

Claims (7)

(57) [Claims] 1. A water-swellable polyurethane resin layer (A) containing a powder of an inclusion compound in which an isothiocyanate is included in a cyclodextrin, wherein the (A) includes an isothiocyanate in a cyclodextrin. An antibacterial film, which is obtained by mixing and dispersing a powder of the clathrate compound in a hydrophilic polyurethane prepolymer (1) having a terminal isocyanate group, followed by moisture curing. 2. A water-swellable polyurethane resin layer (A) containing a powder of an inclusion compound in which an isothiocyanate is included in a cyclodextrin, wherein the (A) includes an isothiocyanate in a cyclodextrin. An antibacterial film characterized by being obtained by mixing and dispersing the obtained clathrate compound powder in a hydrophilic polyurethane prepolymer (1) containing terminal isocyanate groups and a polyether polyol (2). 3. The antibacterial film according to claim 1, wherein (1) is a hydrophilic polyurethane prepolymer having a terminal isocyanate group obtained by reacting a polyisocyanate with a polyether polyol (2). 4. The antibacterial film according to claim 2, wherein (2) has an oxyethylene content of 30 to 100% based on the weight of the total oxyalkylene. 5. The antibacterial film according to claim 2, wherein (2) is oxyethylene alone or an oxyethylene / oxypropylene addition copolymer polyether polyol. 6. The antimicrobial film according to claim 1, wherein the water swellable polyurethane resin has a water absorption capacity of 100% or more. 7. Having (A) on a synthetic resin film or sheet (B) having a through-hole or a nonwoven fabric and / or natural pulp (C) made of synthetic resin, or (B) and (C) The antibacterial film according to any one of claims 1 to 6, wherein (A) is interposed therebetween.