JP5631783B2 - Antibacterial polyurethane - Google Patents

Description

  The present invention relates to an antibacterial polyurethane, and more particularly to an antibacterial polyurethane containing a polyurethane in which an active hydrogen compound having a metal-trapping site is incorporated into a polymer skeleton.

  Polyurethane foam is used for various applications. For example, seating sheets for automobiles, train cars, etc., housing building materials such as sound absorbing materials provided inside ceilings, walls, etc., cosmetics and medical supplies such as other foundation puffs, medical pads, etc. . In these applications, when there is a problem such as odor due to the growth of fungi such as fungi, it may be required to impart antibacterial properties to the polyurethane foam.

  Therefore, by adding an inorganic antibacterial agent such as one in which silver, copper, zinc, or metal ions are held in zeolite to the polyurethane foam foaming raw material, A method for obtaining a polyurethane foam having an antibacterial property in which an agent is integrally dispersed has been proposed (Patent Document 1).

JP-A-10-114812

  In the polyurethane foam obtained by the method of Patent Document 1, sufficient antibacterial effect was not obtained. Then, an object of this invention is to provide the polyurethane which has higher antimicrobial property.

The present invention (1) is, possess a polyurethane metal scavenging active hydrogen compound having a metal capture sites were incorporated into the polymer backbone, and a antimicrobial metal component held by the metal capture site of the polyurethane,
The metal-capturing active hydrogen compound is alginic acid or a salt thereof, or a single-stranded or double-stranded oligonucleotide or polynucleotide;
Said polyurethane, said metal scavenging active hydrogen compound with at least reacting a prepolymer having at least two isocyanate groups, in water, characterized in polyurethane der Rukoto obtained, an antibacterial polyurethane.

The invention ( 2 ) is the antibacterial polyurethane according to the invention (1), wherein the antibacterial metal component is any one metal component selected from the group consisting of silver, copper and zinc. .

The invention ( 3 ) is the antibacterial polyurethane according to any one of the inventions (1) to ( 2 ), wherein the antibacterial metal component is contained in an amount of 0.01 to 10 wt%.

The present invention ( 4 ) is the antibacterial polyurethane according to any one of the inventions (1) to ( 3 ), wherein the polyurethane is a foamed polyurethane.

  In the antibacterial polyurethane according to the present invention, the metal capturing site is present on the polyurethane surface, and the antibacterial metal component is retained on the urethane surface by the metal capturing site. It has particularly high antibacterial properties because it has high contact efficiency with a fluid such as liquid or gas.

The antibacterial polyurethane according to the present invention comprises a polyurethane in which an active hydrogen compound having a metal scavenging site is incorporated in a polymer skeleton, and an antibacterial metal component held by the metal scavenging site of the polyurethane. Features. “Incorporated into the polymer backbone” means that it is incorporated into the main chain or side chain of the polyurethane via a covalent bond by a condensation reaction or addition reaction, or is bonded to a part of the functional group contained in the polyurethane. It means having.

  The antibacterial polyurethane according to the present invention has a metal-capturing site on the surface of the polyurethane, and the anti-bacterial metal component can be retained on the urethane surface by the metal-capturing site. Since the contact efficiency with a fluid such as liquid or gas that is an antibacterial object is high, it has particularly remarkable antibacterial properties. Also, according to the antibacterial polyurethane according to the present invention, unlike the conventional case, the antibacterial metal component is held by the metal-capturing site incorporated in the urethane polymer skeleton, so that the metal content can be significantly increased. Since it is possible, it is considered that it exhibits excellent antibacterial properties. Here, the surface of the urethane means an interface between the urethane and the outside of other liquid or gas. For example, when the urethane is foamed polyurethane, the surface of the cell or the like formed in the foamed surface. Corresponds to the urethane surface referred to here.

  The polyurethane according to the present invention is preferably a foamed polyurethane. Since it is a foam, the surface area of the polyurethane is increased, so that more antibacterial metal components can be retained, and thus higher antibacterial properties are exhibited.

The polyurethane according to the present invention is preferably a hydrophilic polyurethane. By being hydrophilic, it becomes easy to absorb more water, so that it is easy to hold the antibacterial metal component and it is easy to make contact with the aqueous liquid to be antibacterial.
Hereinafter, each component of the antibacterial polyurethane according to the present invention will be described in detail.

<Polyurethane>
Next, the “polyurethane” according to the present invention is a structure obtained by reacting at least two active hydrogen compounds with an isocyanate compound containing at least two isocyanate groups, as in the case of ordinary polyurethanes. It is preferable to use an active hydrogen compound having a metal-trapping site as at least a part of the hydrogen compound. As a result, the obtained polyurethane has an active hydrogen compound having a metal capture site bonded to the polymer skeleton of the polyurethane via a covalent bond, so that the metal capture site is hardly eluted from the polyurethane. In addition to the active hydrogen compound and the isocyanate compound, those added in the reaction for obtaining the polyurethane may include a foaming agent, a catalyst, a surfactant, a foam stabilizer, and other additives.

“Active hydrogen compound” refers to a compound having a hydrogen atom that is reactive with an isocyanato group. For example, a compound having OH, NH ₂ or the like bonded to O or N having a high electronegativity (eg, organic compound) Can be mentioned.

  The “metal capturing site” means a site capable of capturing a metal.

  The “polyurethane” according to the present invention is not particularly limited, and includes all of soft, semi-rigid, hard and the like, and is preferably soft from the viewpoint of wide range of use and workability. The “polyurethane” according to the present invention may be non-foamed (solid), closed-cell foam, or open-cell foam. However, an open-cell foam is preferable from the viewpoint of treatment effect.

  Here, the various raw materials used when manufacturing the said polyurethane are demonstrated in order.

(Active hydrogen compound)
Examples of the “active hydrogen compound” include a compound having an active hydrogen group such as a hydroxyl group, a carboxyl group, an amino group, a phosphate group, a mercapto group, and more specifically, a polyol having at least two hydroxyl groups, Examples include polyamines having two amino groups. It is preferable that at least a part of the “active hydrogen compound” is a metal-trapping active hydrogen compound. Here, the metal-trapping active hydrogen compound means an active hydrogen compound having a metal-trapping site. The metal-trapping active hydrogen compound is preferably an active hydrogen compound having at least two active hydrogen groups in addition to the metal-trapping site. Although it does not specifically limit as a metal capture | acquisition part, For example, a metal capture group and a nucleotide chain are mentioned. Although it does not specifically limit as a metal capture group, For example, a carboxyl group, a hydroxyl group, a phosphate group, a sulfone group etc. are mentioned. Among these, it is preferable to have a carboxyl group. In addition, the salt of the compound which has these metal capture groups may be sufficient. More specifically, the metal-trapping active hydrogen compound is not particularly limited, and examples thereof include alginic acid and nucleotide chains.

  Here, alginic acid has a chain structure in which β- 1,4-linked D-mannuronic acid (M) and α-1,4-linked L-guluronic acid (G) are linked (as described later, When extracted from natural brown algae, the M / G ratio varies depending on the type of raw material and the season). The term “alginic acid” as used in the present specification includes not only alginic acid but also alginic acid salts and alginic acid derivatives (however, the carboxyl group and the hydroxyl group are limited to those not completely modified), for example, Examples include alginic acid derivatives such as alginic acid; alginates such as sodium alginate, calcium alginate, and ammonium alginate; and partial esters such as propylene glycol alginate (for example, 30 to 150 cP). Among these, water-soluble alginates (preferably alkali metal salts, particularly preferably sodium alginate) are preferable. Further, the degree of polymerization of “alginic acid” is not particularly limited, but for example, 80 to 600 is preferable, and about 300 to 400 is more preferable. Here, it is preferable to use alginic acid in a natural product in view of production cost, use of unnecessary materials, and the like. For example, alginic acid is known as a dietary fiber contained in brown algae. Here, the brown algae used as a raw material for alginic acid is not particularly limited. For example, in addition to edible kombu and wakame, sujime, Ainuwakame and Uganomok that are rarely used in industry for reasons such as non-edible It is. Furthermore, a disposal comb after removing the dashi can be used. A method for extracting alginic acid from brown algae is described in, for example, “From Kushiro Water Test No. 85 (2005) 13-15”.

  The nucleotide chain of the present invention means a single-stranded or double-stranded oligonucleotide or polynucleotide, and the base composition, base sequence order, base sequence length, etc. are not particularly limited, and any oligonucleotide or polynucleotide Nucleotides can be used. Such nucleotide chains include single-stranded or double-stranded DNA, single-stranded or double-stranded RNA, single-stranded or double-stranded cDNA, DNA / RNA hybrid, cDNA / DNA hybrid, cDNA / RNA hybrid, and the like. Illustrated. A double-stranded nucleotide chain having a double helix structure is preferable in that it can exhibit excellent capture properties by using intercalation. In the present invention, one or more of the above nucleotide chains may be used. The nucleotide chain can be obtained by a conventional method from a microorganism such as Escherichia coli or yeast, or from any site / organ / tissue of animals and plants. For example, it can be obtained from the testis or thymus of an animal such as chicken, cow or pig. In particular, fish larvae such as salmon, herring, trout, and cod contain a large amount of nucleotides such as DNA in the nucleus and have been discarded in the past, so that they can be used as raw materials for mass production of nucleotide chains at low cost. Is suitable. In order to obtain a nucleotide chain from a baby, for example, after removing the skin, muscles, blood vessels, etc., the oil is removed and purified. Alternatively, the nucleotide chain of the present invention can be artificially synthesized by a biotechnological method or chemical synthesis.

  Here, as a physical property of polyurethane, it is ideal that water absorption is high. Therefore, the polyurethane is preferably a hydrophilic polyurethane. In this case, it is preferable to add a hydrophilic polymer polyol (for example, one containing a hydrophilic unit such as an oxyethylene unit or a hydroxyethylacrylic acid unit) as the “other active hydrogen compound”. As a specific example, as the “other active hydrogen compound” used as an optional component in order to form a hydrophilic and soft polyurethane, a polyether polyol is preferable, which may be used alone or in combination of two or more. Those having an average of 2.0 to 3.5 hydroxyl groups are preferred. In addition, the hydroxyl-containing surfactant mix | blended as a below-mentioned surfactant may comprise some polyols used together.

  Here, examples of the hydrophilic polyether polyol include polyethylene glycol, and a copolymer of oxyethylene units and oxypropylene units in which the polyol has an oxyethylene unit of 10% by weight or more. It may be a copolymer containing a unit such as an oxytrimethylene unit or an oxytetramethylene unit. The oxyethylene unit is preferably 20% by weight or more, more preferably 50% by weight or more, and the hydrophilicity becomes remarkable. The copolymer may be a random copolymer or a block copolymer. The linear polyether polyol uses a dihydric alcohol such as ethylene glycol, propylene glycol, neopentyl glycol, diethylene glycol or dipropylene glycol as a starting material, and a cyclic oxide compound such as ethylene oxide and, if necessary, propylene oxide. Can be synthesized by ring-opening polymerization. The branched polyether polyol uses a trivalent or higher polyhydric alcohol such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, glucose, sucrose as a starting material, and a cyclic oxide compound similar to the above. By synthesis by ring-opening polymerization, a branch unit derived from the above polyhydric alcohol can be included in the molecule. Alternatively, branching may be introduced into the molecule by first synthesizing a bifunctional polyol and then reacting with a trihydric or higher polyhydric alcohol. The number average molecular weight of the polyether polyol is usually 800 to 4,000, preferably 900 to 3,500.

(Isocyanate compound)
Next, the “isocyanate compound containing at least two isocyanato groups” is not particularly limited as long as it contains at least two isocyanato groups in the molecule. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate Isocyanate, mixture of the two, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl polyisocyanate, mixture of the two Aromatic isocyanate compounds such as m-xylene diisocyanate and tetramethyl m-xylene diisocyanate; tetramethylene diisocyanate, hexamethylene diisocyanate, cyclohexylene diisocyanate, isophoro Diisocyanate, aliphatic or cycloaliphatic isocyanate compounds such as dicyclohexylmethane diisocyanate; their isocyanurate, allophanate body, biuret, etc. are exemplified, tolylene diisocyanate and diphenylmethane diisocyanate are preferred.

  It is also possible to use a prepolymer obtained by previously reacting these isocyanate compounds with an active hydrogen compound such as a polyol. For example, a prepolymer having at least two isocyanato groups at the molecular terminals obtained by reacting an isocyanate compound having at least two isocyanato groups with a polymer polyol can also be used as the isocyanate compound. Examples of the polymer polyol include polyether polyol (for example, polyether polyol as the above-mentioned “other active hydrogen compound”) and polyester polyol. Among these, it is particularly preferable to use a prepolymer obtained by reacting 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate or a mixture of both with a polyol.

  The compounding amount of the isocyanate compound is that the end of the prepolymer is blocked with an isocyanato group-containing group, and the reaction with water forms a polyurethane in which alginic acid and nucleotide chains are incorporated into the polymer backbone, and its flexibility and hardness change over time. Therefore, the number of isocyanate groups relative to the hydroxyl group of the polyol is preferably 1.5 to 3.5, and more preferably 2.0 to 3.0.

  Here, as described above, “hydrophilic polyurethane” is preferable as the polyurethane. When the hydrophilic polyurethane is produced, at least a part of the “isocyanate compound having at least two isocyanato groups” is added to the preform. It is preferred to use a polymer.

  In the above, since the main material at the time of manufacturing the polyurethane which concerns on this invention was demonstrated, an auxiliary component is demonstrated below.

(Foaming agent)
When a polyurethane is obtained by the reaction of an active hydrogen compound and an isocyanate compound, it is preferable to add a foaming agent. An example of the foaming agent is water. In particular, when the metal-trapping active hydrogen compound and the prepolymer are reacted, it is preferable to perform the reaction in water to obtain a polyurethane foam.

(catalyst)
In addition, in the reaction of an active hydrogen compound (for example, alginic acid, polyol, etc.) and an isocyanate compound having at least two isocyanato groups (for example, the aforementioned prepolymer), the reaction is completed at a lower temperature and / or in a shorter time. Therefore, you may mix | blend a catalyst. Such catalysts include triethylamine, triethylenediamine, N, N, N′N′-tetramethylethylenediamine, N, N, N′N′-tetramethyltetramethylenediamine, N, N, N′N′-tetra. Amines such as methylhexamethylenediamine, 1,4-diaza [2.2.2] bicyclooctane, N-ethylmorpholine; metal organics such as tin octoate, tin naphthenate, zinc octoate, zinc naphthenate Examples thereof include acid salts; organotin compounds such as dibutyltin dioctate and dibutyltin dilaurate; metal chelate compounds such as acetylacetonatoiron and the like. In addition to these catalysts, a catalyst that promotes dimerization and trimerization of the diisocyanate compound, for example, a tertiary amine such as pyridine may be blended.

(Surfactant, foam stabilizer)
Furthermore, in the case of producing “hydrophilic polyurethane” which is a suitable polyurethane, the formation of polyurethane by the reaction of the prepolymer, water, and a metal-trapping active hydrogen compound (also a hydrophilic polyol in some cases) is made more uniform. In order to perform (performed in an emulsified state), a surfactant may be added. Surfactants include amphoteric surfactants such as carboxylic acid type, sulfonic acid type, sulfate ester type, and polymer type; and oxyethylene / oxypropylene block copolymers, polyoxyethylene alkyl ether, polyoxyethylene Nonionic surfactants such as alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, and glycerin fatty acid esters are preferably used, and one or more of them may be used in combination. Here, in order to obtain a homogeneous and good foam, a polyoxyethylene / polyoxypropylene block copolymer; a nonionic type such as polyoxyethylene alkyl ether such as polyoxyethylene cetyl ether and polyoxyethylene stearyl ether It is preferable to foam in the presence of a surfactant and / or a foam stabilizer such as a polysiloxane / polyoxyalkylene graft copolymer.

  Of these surfactants, those having a plurality of hydroxyl groups in the molecule, such as an oxyethylene / oxypropylene block copolymer, react with the isocyanate group of the prepolymer to form part of the polyurethane. Configure. In addition, those having one hydroxyl group in the molecule, such as polyoxyethylene alkyl ether, react with the isocyanate group of the prepolymer to form the side chain of the polyurethane, and therefore can be used as an active hydrogen compound. .

(Other additives)
In addition, if necessary, a filler, a colorant, a stabilizer, and the like may be blended. Furthermore, depending on the application, various components that are essential or suitable for the application (for example, flame retardant components, bactericidal components, Perfume ingredients etc.) may be blended.

<Antimicrobial metal component>
The antibacterial polyurethane according to the present invention has an antibacterial metal component held by a metal-trapping site. The antibacterial metal component is not particularly limited as long as it is a metal having antibacterial properties, but at least one metal component selected from the group consisting of silver, zinc, and copper is preferable. The form of the metal component is not particularly limited, and may be a metal or a metal ion. In the present invention, these metals are used while being held at a metal-trapping site incorporated in the polymer skeleton of the polyurethane. In other words, these antibacterial metal components are not used by being embedded in the polyurethane as in the prior art, but are captured in the polyurethane in a state of being captured by the metal capturing group formed on the surface of the polyurethane. Presumed to exist. Therefore, since these antibacterial metal components are present in a state where they are exposed on the polyurethane surface, they are held in a state where the antibacterial properties can be exhibited more efficiently.

  The antibacterial metal component source is not particularly limited as long as it is a metal-containing substance that becomes an aqueous solution. Here, as silver used as an antibacterial metal component source, silver nitrate, silver acetate, etc. are mentioned, for example. Similarly, examples of zinc include zinc nitrate and zinc chloride. Similarly, examples of copper include copper chloride and copper nitrate. The content of the antibacterial metal component in the antibacterial polyurethane is not particularly limited, but is preferably 0.01 to 10 wt%, more preferably 0.05 to 10 wt%, and 0.05 to 3 wt%, for example. Is more preferred.

Production Method Next, a method for producing the antibacterial polyurethane according to the present invention will be described. In addition, in the item of the polyurethane as described above, a part of the description related to the manufacturing method has already been made, so the description will be omitted. First, the production method includes a step of reacting at least a metal-trapping active hydrogen compound with an isocyanate compound containing at least two isocyanato groups. In this step, it is preferable to use a prepolymer method for producing foamed polyurethane by using a prepolymer as the isocyanate compound and further adding water as a foaming agent to the reaction system. The prepolymer has both excellent reactivity and excellent mechanical properties (flexibility and elasticity). Moreover, the polyurethane foam excellent in mechanical characteristics can be obtained by the reactivity of a prepolymer and a water | moisture content. Hereinafter, a typical production method (not particularly limited) will be described by taking a prepolymer method as an example.

  More specifically, in the prepolymer method of the present invention, a prepolymer production process for producing a prepolymer having an isocyanato group at the terminal, and a foamed polyurethane in which a metal-trapping active hydrogen compound and the prepolymer are reacted in water. Manufacturing process.

  First, in the prepolymer production process, a reaction vessel equipped with a stirrer and a heating / cooling device is placed in an inert gas atmosphere such as nitrogen, and a polyol is charged, for example, polyethylene glycol (average molecular weight 1,000). In this case, while stirring at 45 ± 5 ° C., if necessary, a polyfunctional compound such as trimethylolpropane is added and the temperature is increased, and a trifunctional unit and three hydroxyl groups are added to the molecule by a dehydration reaction. A polyether polyol having oxyethylene units other than the trimethylolpropane unit at the branch point is obtained. Subsequently, an isocyanate compound containing at least two isocyanato groups is added at a liquid temperature of 50 to 60 ° C. By reacting at 110 ± 5 ° C. for 2 hours, a prepolymer having an isocyanate group at the molecular end can be synthesized. The prepolymer can also be purified by cooling to 50 ° C. or lower and passing through a filter. The reaction proceeds even without a catalyst, but a catalyst may be added as necessary. Here, when manufacturing the said prepolymer, it is preferable to make it react so that the molar ratio of an isocyanate group may be 1.5-3.5 with respect to the hydroxyl group of a polyol, 2.0-3.0 It is more preferable to make it react so that it may become.

  On the other hand, subsequently, in the foamed polyurethane production process, the foamed polyurethane is obtained by reacting the metal-trapping active hydrogen compound and the prepolymer while foaming. Here, the foaming method is particularly preferably foamed by reacting with the moisture in water. In this step, more specifically, a metal scavenging active hydrogen compound is added to water, and a metal scavenging activity such as alginic acid containing additives such as a catalyst, a surfactant and / or a foam stabilizer as necessary. An aqueous solution of a hydrogen compound is prepared. And the said prepolymer and the said aqueous solution are violently mixed at room temperature, it is made to react in an emulsion state, bridge | crosslinking and foaming are advanced, and hydrophilic polyurethane is obtained. In producing the hydrophilic polyurethane, excess water is used and the foam is formed at a relatively low temperature. Therefore, this method is suitable from the viewpoint of preventing thermal decomposition of alginic acid and nucleotide chains.

  It should be noted that the metal-capturing active hydrogen compound, water, and, if necessary, a catalyst, a foam stabilizer and / or a surfactant are blended and dispersed by the so-called one-shot method, regardless of the prepolymer method as described above. In addition, an isocyanate compound is vigorously mixed and reacted with the premix at room temperature to proceed with crosslinking and foaming to obtain a polyurethane in the same manner.

  Subsequently, the antibacterial polyurethane according to the present invention can be obtained by bringing the obtained polyurethane and metal into contact with each other so as to retain the antibacterial metal component in the metal-trapping site. For example, an aqueous solution of an antibacterial metal salt is impregnated with polyurethane to capture the antibacterial metal component. Thereafter, the polyurethane may be washed and dried.

  Here, the impregnation time of the polyurethane is, for example, preferably 1 minute to 48 hours, more preferably 1 hour to 35 hours, and particularly preferably 20 hours to 30 hours. The concentration of the aqueous solution of the antibacterial metal salt used for contact is preferably 0.01 mmol% or more, for example. Although an upper limit is not specifically limited, For example, it is 1000 mmol%.

Applications The antibacterial polyurethane according to the present invention is used for applications where antibacterial properties are required, for example, daily necessities (for example, walls, seat cushions, sofas), medical supplies, sanitary products, electrical appliances, humans and animals. Used for products distributed in the living environment.

  More specifically, seat cushions for automobiles, construction machinery, railway vehicles, etc., cover fabric laminate backing materials, cushioning materials such as door trims and center pyra garnishes, sealing materials, sound absorption and vibration control materials such as floor ceilings, etc. Equipment, motorcycle-related products such as saddles, air filters, oil filters, helmet linings, rider cushions, various sound-absorbing materials, air-conditioning filters, liquid-tight / air-tight sealing materials, sound-proofing flooring materials, chairs, Furniture such as sitting chairs, sofas, and cushions, mattresses, bedding and mattresses, pillows, bed pads, and other interior-related products such as cushions, various cushions, carpets / mats lining, kotatsu mats / hangers, etc. Packaging equipment such as equipment, food and fruit packing materials, fresh fish trays, kitchen cleaners, body soup Cleaners for shoes, shoe polish cleaners, car wash cleaners, side gathers for diapers, shoes (skin lining, insole, inner boots), slippers core, stuffed items such as stuffed toys, cosmetics puffs, and other daily goods, shoulders and bras Padding, clothing material such as cold protection liner, seedling / horticultural soil, hydroponics material, fish culture material, fence impact absorbing wall, exercise landing mat, mannequin body, marine chair cushion, playground equipment It is used for applications such as balls, sound-absorbing chamber sound absorbers, wheelchair cushions, and heat insulation / heat insulation materials.

  Among these, it is preferable to use them as seedling / horticultural soil, hydroponics material, and fish culture material. By using for these purposes, sterilization can be performed without applying a disinfectant such as agricultural chemicals, so there is no concern about contamination of agricultural crops or fish. In addition, for example, when used as a car seat material, antibacterial polyurethane can be used to prevent, for example, sweat odor.

  Hereinafter, the present invention will be described in more detail by way of examples. In the following examples, “part” means “part by weight”, and the compounding ratio and the like indicate a weight ratio (eg, wt%). The technical scope of the present invention is not limited by these examples.

Production Example 1 (Prepolymer production)
100 parts of polyethylene glycol having a number average molecular weight of 1,000 is charged into a reaction vessel, heated to 50 ° C. to form a liquid, then heated to 65 ° C., 4.7 parts of trimethylolpropane and 1.0% of potassium hydroxide. Part was added and stirred to melt trimethylolpropane, and a terminal reactive intermediate was obtained by dehydration reaction. By cooling to 40 ° C. and neutralizing potassium hydroxide, a polyether polyol having a trifunctional unit and three hydroxyl groups in the molecule and consisting of oxyethylene units other than the trimethylolpropane unit at the branch point is obtained. Obtained. To this, 54 parts of an 80:20 mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate was added and reacted at 110 ° C. for 2 hours, whereby the molecular terminal was blocked with an isocyanato group. Polymer P-1 was obtained as a pale yellow liquid. The NCO group content was 8.5%, and the viscosity at 25 ° C. was 27.5 Pa · s. Its number average molecular weight was 1,800.

Production Example 2 (Production of hydrophilic foamed polyurethane (alginate foam))
Sodium alginate {manufactured by Wako Pure Chemical Industries, Ltd., primary sodium alginate 300-400} and polyoxyethylene / polyoxypropylene / polyoxyethylene block copolymer having hydroxyl groups at both ends (number average of polyoxypropylene moieties) 1 part of molecular weight 1,750, oxyethylene unit content 20) was added to 100 parts of water and stirred to prepare an alginate aqueous solution in which a surfactant (the block copolymer) was dispersed. While vigorously stirring this, 100 parts of pre-synthesized prepolymer P-1 was mixed at 20 ° C. and reacted in an emulsified state to obtain a urethane foam in which alginic acid was incorporated into the crosslinked structure. Since the foam contained water, it was left to stand at room temperature for one day to evaporate water. The obtained urethane foam was open-celled with a cell number of 50/25 mm and a density of 85 kg / m ³ . When this foam was immersed in water, it had a water absorption of 18 times its own weight and was hydrophilic.

Production Example 3 (Prepolymer production)
A reactor equipped with a mixer is placed in a nitrogen atmosphere, the temperature is set to 45 ° C., 100 parts of polyethylene glycol having an average molecular weight of 1,000 is charged, the temperature is raised while stirring, and 4.7 parts of trimethylolpropane is added. Then, 1 part of potassium hydroxide was added, and a polyether polyol having a trifunctional unit and a hydroxyl group at the molecular end and consisting of an oxyethylene unit was obtained by dehydration reaction. Next, while maintaining the liquid temperature at 50 to 60 ° C., 53.5 parts of a 80:20 mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate was added and reacted at 110 ° C. for 2 hours, whereby Was blocked with an isocyanato group to obtain a prepolymer P-2 as a pale yellow liquid. It cooled to 50 degrees C or less, filtered, and used for the following experiments. The average molecular weight was about 1,800, the NCO group content was 8.5 g / 100 g, and the viscosity at 25 ° C. was 19 Pa · s.

Production Example 4 (DNA urethane foam)
In Production Example 4, the following materials were used in addition to the prepolymer P-2 (Production Example 3).
D-1: Salmon white-derived DNA, 3% by weight aqueous solution, manufactured by Biochem, DNA-Na-HP (strap) nitrogen 12.4% or more, phosphorus 8% or more E-1: poly having hydroxyl groups at both ends Oxyethylene / polyoxypropylene / polyoxyethylene block copolymer, average molecular weight of polyoxypropylene part 1,750, oxyethylene unit content 20

100 parts of P-2 obtained in Production Example 3 and 100 parts of D-1 were mixed, and 1 part of E-1 was added thereto and foamed at room temperature. This foam was allowed to stand at room temperature for 3 days and dried until the linear shrinkage reached 85% before drying to obtain a polyurethane foam (open cell foam, density 85 kg / m ³ , cell number 50/25 mm).

Example 1 (Production of antibacterial polyurethane: alginic acid)
A 0.1 mmol / L (100 μmol / L) aqueous silver nitrate solution was impregnated with the polyurethane of Production Example 2 (alginic acid) for 24 hours, washed and dried to fix the silver in the foamed polyurethane. As a result, the antibacterial polyurethane according to Example 1 was obtained.

Example 2 (Production of antibacterial polyurethane: DNA)
A 0.1 mmol / L (100 μmol / L) aqueous silver nitrate solution was impregnated with the polyurethane of Production Example 4 (DNA) for 24 hours, washed and dried to fix the silver in the foamed polyurethane. As a result, the antibacterial polyurethane according to Example 2 was obtained.

Comparative Example 100 g urethane urethane polymer was added to 100 g of 0.5 wt% aqueous solution of silver zeolite, and reacted and foamed to obtain an antibacterial polyurethane of a comparative example. In addition, the silver zeolite used here used Zeomic by Sinanen Zeomic Co., Ltd.

Metal content measurement In order to measure the metal adhesion content of urethane foam used in the following antibacterial tests, the "urethane foam part" which is an organic substance that gets in the way of analysis is pretreated and eluted in nitric acid (1 + 1) Then, measurement was performed by flame atomic absorption method at measurement wavelengths of 328.1 nm and 338.3 nm. As a result, when DNA was used (Example 2), it was 0.44 wt% with respect to the total weight, and when alginic acid was used (Example 1), it was 0.56 wt%.

Antibacterial test Technical Committee of Antibacterial Products Antibacterial activity evaluation test method of antibacterial processed products of test method (2003 version) An antibacterial activity evaluation test was conducted based on Test Method II (2003 version) (shake method). Here, the total surface area was 32 ± 5 cm ² and the number of bacteria was measured over time after shaking conditions. The results are shown in Tables 1-3. Here, DNA-Ag is the antibacterial polyurethane according to Example 2, ALG-Ag is the antibacterial polyurethane according to Example 1, and Zomic is the polyurethane using the silver zeolite of the comparative example. Blank is a polyurethane produced by using 100 g of NB9000B prepolymer in 100 g of water, and is a sample having a thickness of 3 mm. The upper control is a value in the control experiment in the example and the comparative example, and the lower control is a value in the control experiment in relation to the blank.

Claims (4)

And polyurethane metal scavenging active hydrogen compound having a metal capture sites were incorporated into the polymer backbone, and a antimicrobial metal component held by the metal capture site of the polyurethane possess,
The metal-capturing active hydrogen compound is alginic acid or a salt thereof, or a single-stranded or double-stranded oligonucleotide or polynucleotide;
It said polyurethane, characterized and the metal-scavenging active hydrogen compound, and a prepolymer having at least two isocyanato groups, the at least reacted polyurethane der Rukoto obtained in water, polyurethane antibacterial.   The antibacterial polyurethane according to claim 1, wherein the antibacterial metal component is any one metal component selected from the group consisting of silver, copper, and zinc. The antibacterial polyurethane according to any one of claims 1 to 2 , wherein the antibacterial metal component is contained in an amount of 0.01 to 10 wt%. The antibacterial polyurethane according to any one of claims 1 to 3 , wherein the polyurethane is a foamed polyurethane.