JP5223885B2 - Gelatin cross-linked gel-polyurethane-based cold medium and cold insulation material - Google Patents

Description

  The present invention relates to a gelatin-crosslinked gel-polyurethane-based cold medium, particularly a cold medium used for cooling or heating by storing heat, and a cold insulation material for keeping cold or keeping warm with this cold medium.

  As a cold insulation material to be put in an ice pillow, ice bag, cold insulation container, or a heat insulation material such as a hot water tampo or a squirrel furnace, a cold insulation heat material in which a cold heat medium is contained in the container is used. Water having a large heat capacity is used as a cooling medium for keeping cold or keeping warm, but in order to keep cold or keeping warm, a thickener such as CMC (carboxymethylcellulose) is added to the water to make it viscous. A cooling medium with increased heat resistance is used. In other words, in a low viscosity medium such as water, convection occurs and heat leaks unnecessarily, and in order to prevent this, convection is prevented by using a cooling medium whose viscosity is increased by a thickener, and this is maintained. The cooling effect is enhanced and the heat retention time is maintained. However, in order to increase the viscosity to such an extent that convection can be prevented, it is necessary to add a large amount of a thickener such as CMC, which increases the cost, reduces the amount of water with high heat capacity, and reduces the overall heat capacity. Get smaller.

  In addition, a pack-shaped cold insulation material containing such a cold medium in a container is used as a cold insulation material in a state of being frozen in a refrigerator or freezer, or immersed in hot water, or in some cases microwaved in a microwave oven. Used as a heat insulating material by heating. However, when such a cold insulation heat material is used, if the cooling or heating cycle is repeated, the aqueous phase and the thickener phase are separated, and the cold insulation heat effect is lowered. In particular, when frozen and used as a cold insulation material, ice crystals grow by freezing, so when melted, water separates like agar, frozen tofu, etc., and does not return to the original viscous solution, reducing the heat insulation effect To do.

  In addition, a pack-shaped cold insulation material that contains such a cooling medium in a container is a container composed of a thin sheet such as a resin film bag, but when used for cooling or heating the human body, etc. Because it is cooled and heated through the thin sheet as described above, it cannot be raised to a very high temperature, and in the case of freezing, it cannot be hardened and deformed, and it cannot be used directly by hitting the human body. There are also problems such as bad.

  Patent Document 1 (Japanese Patent Laid-Open No. 2008-156582) proposes a cold-retaining agent having a gel-like form in which water is absorbed in a crosslinked sodium polyacrylate high water-absorbing polymer. This is what absorbs water in a superabsorbent resin and uses it as a heat medium, and can increase the amount of water absorbed in the resin, but when the cooling or heating cycle is repeated, the water phase and the resin are separated, Cooling heat effect is reduced. This point is not much different from the case of using a conventional thickener, and the same is true when it is used as a heat retaining medium. This phenomenon is presumed to be due to the separation of water from the resin because the water dispersed in the resin with a cross-linked structure flows due to cooling or heating, and especially ice crystals grow in the case of freezing. Like the above, it does not return to the dispersed state in the original cross-linked structure, and the heat insulation heat effect is reduced.

In Patent Document 2 (Japanese Patent Application Laid-Open No. 2008-156588), a gel body is formed by adding a gelling thickener derived from a natural product such as agar, carrageenan, gelatin, and CMC to a saccharide such as a starch degradation product. A cryogen has been proposed. Here, gelatin is said to be used as a gel-forming agent, but this is only used as a thickening agent like agar, carrageenan and CMC, and no use of cross-linked gelatin is shown. For this reason, the cold-retaining agent obtained here is essentially the same as that using a thickener such as a conventional CMC, and the cost increases and the cold-retaining heat effect is low.

JP2008-156582 JP2008-156588

  The object of the present invention is to increase the amount of water contained in the cooling medium, thereby reducing the cost, increasing the heat capacity and extending the cooling heat time, and increasing the cooling heat effect. It is to provide a cooling medium capable of extending the repeated use time without water separating even after repeated cooling or heating cycles, and a cold insulation heat material using the same.

The present invention is the following cooling medium and cold insulation material.
(1) A cold medium containing a composite of a gelatin crosslinked gel containing crosslinked gelatin and water and a polyurethane substrate.
(2) A cold medium containing a granulated or pulverized product containing a composite of a gelatin crosslinked gel containing crosslinked gelatin and water and a polyurethane substrate.
(3) A reaction product of a raw material mixture comprising the granulated or pulverized product of a gelatin cross-linked gel containing a cross-linked gelatin and water and a polyurethane raw material containing a polyol and a polyisocyanate in the above (1) or (2) Including cold medium.
(4) The cooling medium according to any one of the above (1) to (3), wherein the gelatin crosslinked gel contains 2 to 60% by weight of crosslinked gelatin and 40 to 98% by weight of water, and has a jelly strength of 9 to 3000 g.
(5) In any one of the above (1) to (4), the gelatin crosslinked gel is a reaction product of an aqueous sol containing 2 to 59% by weight of gelatin, 1 to 20% by weight of a crosslinking agent and 40 to 97% by weight of water. A cold medium having a jelly strength of 9 to 3000 g.
(6) The cooling medium according to any one of (1) to (5), wherein the polyurethane base material is a polyurethane foam.
(7) The gelatin cross-linked gel according to any one of (1) to (6) above,
A reaction product of a raw material mixture containing a polyol, a polyisocyanate and a polyurethane raw material containing a blowing agent, or a cold medium containing a granulated or pulverized product thereof.
(8) A cold insulation material in which the cooling medium according to any one of (1) to (7) is housed in a container.
(9) A cold insulation material in which the cooling medium according to any one of (1) to (7) is housed in a soft container .
(10) The cold insulation material according to (8) or (9) above, wherein the container is a heat-resistant, microwave-permeable container.

  The gelatin crosslinked gel constituting the cooling medium of the present invention is a gelatin crosslinked gel containing crosslinked gelatin and water. Cross-linked gelatin is obtained by three-dimensionally cross-linking gelatin with a cross-linking agent to form a three-dimensional network structure. Gelatin is a denatured collagen in which the helical structure of collagen, which is a protein in higher animals, is broken, and is a linear polypeptide. By cross-linking this with a cross-linking agent, a three-dimensional network structure is formed. The Gelatin has a high affinity with water and dissolves very well in water, but cross-linked gelatin is similar and absorbs large amounts of water. Moreover, it has a high affinity with water, and it does not separate even after repeated cooling or heating cycles, and can be used repeatedly for a long period of time.

Gelatin cross-linked gel contains 2-60 wt% cross-linked gelatin, preferably 3-50 wt%, and 40-98 wt% water, preferably 50-97 wt%, and has a jelly strength of 9-3000 g, preferably 30-2000 g. Are preferred. Gel jelly strength is JIS
According to K 6503 (2001), it is displayed as the load (g) required to push down the surface of the gel by 4 mm with a probe having a diameter of 12.7 mm. In the case of a fluid gel having a jelly strength of less than 30, the diameter of the probe is Increase to correct. Such gelatin cross-linked gels have a gelatin content of 2 to 59%, preferably 4 to 59%, a cross-linking agent 1 to 20%, preferably 2 to 20%, and water 40 to 97%, preferably 50%. It can be produced by reacting an aqueous sol containing ˜95% by weight, and the reaction product can be used as a gelatin cross-linked gel.

In the present invention, gelatin used as a raw material for crosslinked gelatin has a molecular weight of 10,000 to 500,000, preferably 15,000 to 200,000, but may include those outside this range. . Such gelatin is obtained by denaturing collagen with heat, acid, alkali, enzyme, etc., but commercially available products can also be used. Since the molecular weight of gelatin varies depending on denaturation conditions, for example, the type and concentration of drugs and auxiliaries used for denaturation, temperature, time, and the like, gelatin having the desired molecular weight can be obtained by selecting denaturation conditions. The average molecular weight of gelatin can be determined by measuring the molecular weight distribution according to the Pagii method ninth edition (2002).
As can be seen from the fact that gelatin is used as an adhesive in glue, it has adhesiveness, but cross-linked gelatin that has been cross-linked with a cross-linking agent has reduced adhesiveness, and does not adhere when granulated or pulverized by crushing etc. Maintain shape independently of each other.

Any crosslinking agent may be used as long as it can react with a functional group of gelatin to crosslink, but an ethylenically unsaturated compound-maleic anhydride copolymer, a ring-opening polymer thereof or a salt thereof is preferable. Examples of the ethylenically unsaturated compound include olefins such as ethylene, propylene, butene-1, butene-2, and isobutylene, and other compounds having an ethylenically unsaturated group. The ring-opening polymer is a polymer opened by adding water to an ethylenically unsaturated compound-maleic anhydride copolymer, and the salt thereof is a salt such as an ammonium salt or a sodium salt of the ring-opening polymer. The salt can be formed by reacting the ethylenically unsaturated compound-maleic anhydride copolymer or ring-opening polymer with ammonium hydroxide, sodium hydroxide or the like.

  The ethylenically unsaturated compound-maleic anhydride copolymer is a copolymer of these ethylenically unsaturated compounds and maleic anhydride, and the molar ratio of the ethylenically unsaturated compound and maleic anhydride is 10: 1 to 1. 1:10, preferably 5: 1 to 1: 5, and the average molecular weight is usually 2,000 to 200,000, preferably 3,000 to 100,000. A commercially available product is used as such an ethylenically unsaturated compound-maleic anhydride copolymer. The ratio of ring-opening polymer, ammonium salt, sodium salt, or the like for ring-opening or conversion to a salt is arbitrary, but it is preferable to convert all of the anhydrous rings.

  The gelatin cross-linked gel may be made of a foam in which fine bubbles are dispersed, and may contain other components such as an antibacterial agent, a colorant, a fragrance, an organic solvent, and salts. The antibacterial agent is preferably one that is uniformly dispersed in the crosslinked gelatin. The organic solvent is mainly used as a solvent such as a crosslinking agent or an antibacterial agent, but can be omitted if it is water-soluble. Organic solvents, salts, and the like are sometimes used for freezing point depression, but these may not be used when using latent heat. The content of other components is 0 to 10% by weight, preferably about 0.1 to 5% by weight.

The gelatin cross-linked gel of the present invention is produced by reacting an aqueous sol containing these gelatin, a cross-linking agent and other components added as necessary. At this time, the gelatin and the cross-linking agent react and cross-link so as to embrace water and other components added as necessary, whereby an aqueous gel is formed. Such gelatin cross-linked gel can be produced by reacting the aqueous sol at 20 to 70 ° C., preferably at room temperature to 60 ° C. The gelatin cross-linked gel formed in this way is an aqueous gel in which gelatin is cross-linked with water and other components added as necessary. Even when the concentration of the gel forming agent is low, it has excellent shape retention. Alternatively, a pulverized product or other molded body can be formed.

  When the above-mentioned gelatin crosslinked gel containing crosslinked gelatin and water is integrated with a urethane base material, it is preferably integrated as a granulated or pulverized product of gelatin crosslinked gel. The granulated or pulverized product may be a granulated product granulated at or after the formation of the gelatin cross-linked gel, or may be a pulverized product obtained by pulverizing the formed gelatin cross-linked gel. The granulated or pulverized product may be a spherical shape, a granule having an arbitrary shape such as a pellet, a granular granulated product, or an pulverized product pulverized into an irregular shape. The particle size of the granulated or pulverized product is not limited, but can typically be 0.5 to 20 mm. The amount of the crosslinking agent is selected and the jelly strength is adjusted so that these molded bodies, granulated or pulverized products, etc. maintain their respective shapes in a state of containing water.

The polyurethane substrate constituting the cooling medium of the present invention comprises a reaction product of a raw material mixture containing a polyurethane raw material containing a polyol and a polyisocyanate, or a granulated or pulverized product thereof. This polyurethane base material may comprise a reaction product of a polyurethane raw material not containing gelatin cross-linked gel, or a granulated or pulverized product thereof, but a reaction product of a polyurethane raw material containing gelatin cross-linked gel, or a granular product thereof As the liquefied or pulverized product, those obtained integrally with the gelatin cross-linked gel are preferable. As a result, a cold medium in which the gelatin cross-linked gel and the polyurethane base material are integrated is obtained.

The polyurethane substrate may be a solid material containing no bubbles, but is preferably a polyurethane foam containing cells. In this case, the polyurethane base material is made of a polyurethane foam composed of a reaction product of a raw material mixture containing the gelatin cross-linked gel and a polyurethane raw material containing a polyol, a polyisocyanate and a foaming agent, or a granulated or pulverized product thereof. Is preferred. The polyurethane substrate may be hard, but is preferably soft. The hardness of the polyurethane base material can be adjusted by selecting a polyurethane raw material. Moreover, the polyurethane base material may contain other components, such as an antibacterial agent, a coloring agent, a fragrance | flavor, a filler, and salts.

  Known polyols such as polyhydric alcohols, polyether polyols, and polyester polyols can be used as the polyurethane raw material polyol. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and trimethylolpropane. Examples of the polyether polyol include a polyether polyol obtained by addition polymerization of an alkylene oxide to the polyhydric alcohol or polyamine, and a polymer polyol obtained by polymerizing and finely dispersing a vinyl monomer in a polyalkylene glycol. Examples of the polyester polyol include polyester diols and polyester triols produced by a condensation reaction between the polyhydric alcohol and a low molecular weight carboxylic acid such as adipic acid or phthalic acid.

As these polyols, polyether polyols are preferable, and polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide and propylene oxide to the above polyhydric alcohols or polyvalent amines such as ethylenediamine and triethanolamine, and polyethylene A polymer polyol obtained by polymerizing and finely dispersing a vinyl monomer such as acrylonitrile or styrene in a polyalkylene glycol such as glycol or polypropylene glycol, or a combination thereof is preferable. When these are used in combination, the hardness of the polyurethane base material to be produced can be adjusted by changing the mixing ratio.

  As the polyisocyanate of the polyurethane raw material, known ones such as aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate can be used. Among these, aromatic polyisocyanates such as TDI (tolylene diisocyanate), monomeric MDI (diphenylmethane diisocyanate), and polymeric MDI (polymethylene polyphenylene polyisocyanate) are preferable, and polymeric MDI is particularly preferable.

  Water is used as the foaming agent for the polyurethane raw material, but other known foaming agents may be used. When water is used as the foaming agent, water adhering to the gelatin cross-linked gel mixed with the polyurethane raw material can be used. In addition, known additives such as catalysts and foam stabilizers can be used for the polyurethane raw material. As the catalyst, an amine catalyst such as triethylenediamine or N-alkylmorpholine, a tin catalyst such as stannous octoate or dibutyltin dilaurate, or a mixture thereof may be used. As the foam stabilizer, silicone compounds such as dimethylsiloxane-modified products are used.

  The polyurethane base material can be produced as a molded product by mixing polyurethane raw materials containing the above-mentioned polyol, polyisocyanate and other components, pouring them into a mold, and allowing them to stand. When manufacturing a cooling medium in which the polyurethane base material and gelatin cross-linked gel are integrated, the above polyurethane raw material and granulated or pulverized product of gelatin cross-linked gel are mixed, poured into a mold and allowed to stand and react. As a result, a polyurethane base material can be formed so as to embrace the granulated or pulverized product of gelatin cross-linked gel, and a molded product in which gelatin cross-linked gel is integrally dispersed can be produced. When the polyurethane base material is a polyurethane foam, a cooling medium comprising a polyurethane foam can be obtained by mixing a foaming agent and a foam stabilizer in a polyurethane raw material and foaming during the reaction. The reaction temperature is not limited and proceeds at room temperature, but may be adjusted in the range of 0 to 50 ° C.

  The ratio of the polyol and the polyisocyanate in the polyurethane raw material is a ratio necessary for the formation of the urethane bond. Generally, the equivalent ratio of the active hydrogen of the polyol and the NCO group of the polyisocyanate is 1: (0.9 to 1). About 5). The amount of the catalyst is an amount necessary for the reaction, but is generally about 0 to 5% by weight with respect to the total amount of polyol and polyisocyanate. The amount of the foaming agent and the foam stabilizer is determined by the desired foam size, amount, degree of dispersion, etc., but is generally about 0 to 5% by weight based on the total amount of polyol and polyisocyanate, respectively. . The size, amount, degree of dispersion and the like of the foam are not particularly limited, and those which are uniformly dispersed as open cells are preferable, but closed cells may be used.

  The cooling medium of the present invention includes a composite of the above-mentioned gelatin crosslinked gel containing crosslinked gelatin and water and a polyurethane substrate, and in particular, a gelatin crosslinked gel containing crosslinked gelatin and water and a polyurethane substrate. What consists of the granulated or ground material containing a composite_body | complex is preferable. The composite may be a mixture of a gelatin cross-linked gel and a polyurethane base material, but is preferably a combination of both. The ratio of gelatin cross-linked gel to polyurethane substrate in the composite is 40-97 wt% gelatin cross-linked gel, preferably 50-95 wt%, 3-60 wt% polyurethane substrate, preferably 5-50 wt%. It can be a percentage. In addition to the above, the composite may contain other components such as an antibacterial agent, a coloring agent, a fragrance, a filler, and salts.

  In the case of a composite made of a mixture, a composite is formed by mixing a granulated or pulverized product containing a preformed gelatin cross-linked gel and a granulated or pulverized product containing a preformed polyurethane substrate. Is done. The composite composed of such a mixture may be used as it is as a cooling medium, or may be formed by compression or the like to form a molded body, or may be further granulated or pulverized and used as a granulated or pulverized material.

In the case of a composite composed of an integral product, as described above, a reaction in which a granulated or pulverized product of a gelatin crosslinked gel containing crosslinked gelatin and water and a raw material mixture containing a polyurethane raw material containing polyol and polyisocyanate are reacted. Since the product is an integrated product, the reaction product can be used as it is as a cooling medium, or the granulated or pulverized product can be used as a cooling medium. Further, the granulated or pulverized product may be further molded by compression or the like to form a molded body, or further granulated or pulverized and used as a granulated or pulverized product.

  The cooling medium of the present invention can be used in the form of an arbitrarily shaped molded body, or as a granulated or pulverized product, both in the case of a composite made of the above mixture and in the case of a composite made of an integrated product. . The granulated or pulverized product may be a granulated product granulated at the stage of forming the composite or after the formation thereof, or may be a pulverized product obtained by pulverizing the formed composite. The granulated or pulverized product may be a spherical shape, a granule having an arbitrary shape such as a pellet, a granular granulated product, or an pulverized product pulverized into an irregular shape. The particle size of the granulated or pulverized product is not limited, but can typically be 0.5 to 20 mm. These molded bodies, granulated or pulverized products, etc. are adjusted in hardness by selecting the amount of the polyurethane base material so as to maintain the respective shapes in the composite state.

The cooling medium of the present invention can be used as it is as a heat insulating heat material in the state of a composite of a gelatin crosslinked gel containing the above crosslinked gelatin and water and a polyurethane substrate depending on the use form. The composite cold heat medium can be used as a cold insulation heat material in a state of being accommodated in a container. In the case where the cooling medium is a composite molded body, it may be accommodated in a container after forming the molded body and used as a cold insulation material, but the container is allowed to react in a state where the polyurethane raw material containing the gelatin cross-linked gel is accommodated. According to the shape, a composite molded body can be formed as a reaction product . In the case of a granulated or pulverized product of a composite, it is common to store the granulated or pulverized product granulated or pulverized simultaneously with or after the reaction in a container to constitute a cold insulation material.

  The container for storing the cooling medium is appropriately selected depending on the purpose of use, but a resin bag, a bottle, a tank, or the like is selected. When this container is used as a cryogen, any material and shape can be used. However, when it is used as a heat insulator, a container made of a heat-resistant and microwave-permeable material is used. Preferably, this prevents the container itself from being heated and deteriorated even when microwave heating is performed in a microwave oven. Examples of the microwave permeable material include a low dielectric constant resin. Examples of the low dielectric constant resin include resins having a relative dielectric constant of 5 or less, preferably 3 or less, based on ASTM D150, with a dielectric constant of 1 measured at 1 kHz at room temperature. Examples of the resin having a relative dielectric constant of 5 or less include polystyrene, silicon resin, ABS resin, etc., but polyethylene, polypropylene, polyfluorinated ethylene, etc. having a relative dielectric constant of 3 or less are preferable. A resin having a melting point of more than 100 ° C. such as ethylene fluoride is preferable.

  The container may be formed of a solid film or plate-like sheet, may be formed of a film or plate-like sheet made of a foam, or a combination thereof. For example, in the case of a bag, both sides may be formed of a solid film or plate sheet, or a foam film or plate sheet, or one side is a solid film or plate sheet, and the opposite side. May be formed of a foam film or a plate-like sheet. In addition, these both surfaces may be structured such that a cooling medium directly contacts the outer wall formed of a single film or plate-like sheet, and a liquid chamber such as glycerin or a buffer layer such as sponge is formed between them. May be. It is preferable to use a closed-cell foam as the foam used in the container, because evaporation of water contained in the cold medium can be prevented.

  The cold insulation material formed as described above is used as a cold insulation material in a state of being cooled or frozen in a refrigeration or freezer, or immersed in hot water, or in some cases microwaved in a microwave oven to store heat in a cold medium. It is used as a heat insulating material in the finished state. In use, when used as a cold insulator, the cooling medium absorbs external heat through the container and cools it. When used as a heat insulating material, the heat stored in the cold medium is transferred to the outside through the container and heated. When the cooling medium absorbs heat or dissipates heat and the cooling or heating capacity is reduced, the cold insulation material is cooled or heated again and used.

  Thus, unlike the conventional product, the water phase and the thickener phase are separated in the use of the cold insulation heat material, and the cold insulation heat effect is lowered in the conventional product. Then, water does not separate from the cross-linked gelatin, maintains a stable gel state for a long period of time, and can be used repeatedly for a long period of time. This is the same even when a large amount of water is included exceeding the water content in the conventional product. Even when the moisture is frozen and used as a cold insulation material, ice crystals do not separate and grow due to freezing, and even if they are melted, phase separation does not occur, and the cold insulation heat effect is maintained.

  The phase separation of gelatin cross-linked gel does not occur even when used repeatedly in this way due to the extreme strength of affinity between cross-linked gelatin and water, and a phenomenon that cannot be predicted from conventional polyacrylic acid cross-linked products. It is. Collagen is very biased in amino acid composition. About 35% by weight of glycine, about 11% by weight of alanine, about 21% by weight of proline and hydroxyproline, 2/3 of amino acids are hydrophilic, and collagen itself is highly hydrophilic. . Gelatin in which this is modified has a higher hydrophilicity due to cleavage of covalent bonds or formation of hydroxyl groups. Such a cross-linked gelatin obtained by cross-linking gelatin also has a network structure in a state where the properties thereof are maintained, so that it has excellent water retention and water is difficult to separate from the network structure of the cross-linked gelatin.

  The high hydrophilicity of such cross-linked gelatin is due to the high hydrophilicity of specific gelatin and is greatly different from other proteins. For example, the above-mentioned frozen tofu is formed from soy protein, but water is easily separated by freezing and thawing in the same manner as agar mainly composed of alginic acid. In contrast, cross-linked gelatin is much more hydrophilic, and water does not separate from the cross-linked gelatin even after repeated cooling and heating cycles. For this reason, it is useful as a cooling medium for the cold insulation material.

  Since gelatin is highly hydrophilic, gelatin itself can be used as a cooling medium. However, by cross-linking this gelatin, it has a network structure, so that the water retention is further enhanced and the shape maintaining property is also enhanced. Further, when used as a composite of a gelatin cross-linked gel containing such cross-linked gelatin and water and a polyurethane base material, particularly when used as a granulated or pulverized product, the gelatin cross-linked gel is not granulated or the adhesion between the pulverized products is eliminated. Independent granulations or pulverized products are used as the cooling medium. In this case, a layer of air is formed between the granulated or pulverized products, so that the entire heat does not flow intensively and is transferred from the granulated or pulverized products to other granulated or pulverized products. Heat transfer or heat dissipation is prevented, and heat storage and cold insulation efficiency are increased. The same effect can be obtained when a foam is used for the container.

Granulated or pulverized composite of gelatin cross-linked gel containing polyurethane and water containing cross-linked gelatin and water as a cooling medium, filled into a soft container such as a resin bag, and granulated when used as a cold insulation heat material Or, since there is no adhesion between the pulverized products, the entire filling shape can be freely changed without being granulated or bonded between the pulverized products, and it can be fitted to the shape of the heat transfer surface of the cooled part. It is possible to increase the heat transfer effect. In particular, when the cooling medium is used in a frozen state, if the whole is a single gel layer, the whole becomes a hardened layer as a single frozen layer, and it may not be possible to fit the shape of the heat transfer surface of the cooled part. However, by using a granulated or pulverized product of a cross-linked gelatin composite, the contact surface between the granulated or pulverized products can be shifted to change the entire filling shape. In addition to being able to be fitted to the shape, an air layer is interposed between the granulated or pulverized products, so that rapid cooling is alleviated, heat storage properties are improved, and sustainability and heat insulation efficiency are increased.

When using a cold insulation material that contains a cooling medium in a container, if the container is made of a heat-resistant and microwave-permeable material, the microwave will pass through the container even if it is heated in a microwave. Is not heated, and water contained in the cold medium is heated and stored in resonance with the microwave. For this reason, a container does not deteriorate by heating. Gelatin is also heated in a microwave for having polarity, since water is present, the pressurized heat temperature was kept below the boiling point of water and does not cross-linked gelatin is degraded. In addition, even if the resin is microwave permeable, it may deteriorate in the case of a resin with a low softening point such as polyethylene, but it is a heat resistant resin having a melting point of more than 100 ° C. such as polypropylene and polyfluorinated ethylene. If it exists, there is little deterioration and it can be used repeatedly for a long time.

  Since the cold medium of the present invention includes a gelatin crosslinked gel containing crosslinked gelatin and water, the amount of water contained in the cold medium can be increased, thereby increasing the heat capacity. In addition, since the polyurethane base material is included together with the gelatin cross-linked gel, the concentrated heat flow can be relaxed and the heat retention time can be extended. For this reason, by using these composites, the cost can be reduced, the heat capacity can be increased, the heat retention time can be increased, the heat retention effect can be increased, and the water can be maintained even after repeated cooling or heating cycles. Is not separated, and the repeated use time can be extended.

  The cooling medium comprising the granulated or pulverized composite of the gelatin-crosslinked gel and polyurethane base of the present invention loses the adhesion between the granulated or pulverized gelatin-crosslinked gels, and is independently granulated or pulverized. Is used as a cooling medium, and a layer of air is formed between the granulated or pulverized products, so that the entire heat does not flow intensively and is transferred from the granulated or pulverized products to the granulated or pulverized products. , Wasteful heat transfer or heat dissipation is prevented, and heat storage and cold insulation efficiency are increased.

  The cold insulation heat material of the present invention accommodates a cold medium made of a composite containing gelatin cross-linked gel and a polyurethane base in a container, so that the amount of water contained in the cold medium can be increased, thereby reducing the cost and heat capacity. And the heat retention time can be lengthened to increase the heat retention effect, and even when the cooling or heating cycle is repeated, water is not separated, and the repeated use time can be increased.

  The cold insulation heat material in which the cold medium made of the granulated or pulverized composite of the gelatin-crosslinked gel and polyurethane base of the present invention is housed in a soft container is not bonded to the gelatin-crosslinked gel granulated or pulverized product. It is crunchy and the whole filling shape can be changed freely, it can be fitted to the shape of the heat transfer surface of the cold heat part, the heat transfer effect can be enhanced, and the air layer between granulated or crushed products By interposing, rapid cooling is relieved, heat storage property becomes high, and sustainability and cold insulation heat efficiency become high.

  The cold insulation material in which the cooling medium of the present invention is housed in a heat-resistant, microwave-permeable container is not heated even if microwave heating is performed in a microwave oven, and the water contained in the cooling medium resonates with the microwave. Since the container is heated and stored, the container is not deteriorated by heating and can be used repeatedly for a long time.

(A) is a top view of the cold insulation heat material of one Embodiment, (b) is the AA sectional drawing. (A) is a top view of the cold insulation heat material of other embodiment, (b) is the BB sectional drawing.

  Embodiments of the present invention will be described below with reference to the drawings. In the embodiment of FIG. 1, the cold insulation material 1 is formed in a pack shape in which a cold heat medium 2 composed of a composite of a gelatin crosslinked gel containing crosslinked gelatin and water and a polyurethane base material is accommodated in a container 3. Yes. The whole of the cooling medium 2 may be one lump, but is preferably filled with granulated or pulverized material. The container 3 is composed of a container body 4 having an adhesive portion 4a in the periphery and a lid portion 5 having an adhesive portion 5a in the periphery. The container 3 has a tube shape in which the container body 4 and the lid portion 5 are integrated. You may comprise. Although the container 3 may be a hard container, it is preferable to use a soft container because it can be fitted to the shape of the heat transfer surface of the cooled portion.

  The cold insulation heat material 1 contains a cooling medium 2 made of a composite of a gelatin crosslinked gel containing crosslinked gelatin and water and a polyurethane base material between the container main body 4 and the lid 5, and has an adhesive portion 4 a and an adhesive portion. It is manufactured by adhering 5a with an adhesive or heat seal to form a pack. In the case where the cooling medium 2 consists of one lump, the reaction is carried out in a state in which a raw material mixture containing granulated or pulverized gelatin cross-linked gel and a polyurethane raw material containing polyol and polyisocyanate is contained in the container 3. Thus, the cooling medium 2 is formed. When the cooling medium 2 is made of granulated or pulverized material, the container 3 is filled with the granulated or pulverized material obtained by granulating or pulverizing the preformed cooling medium 2, and the bonding portion 4a and the bonding portion 5a are formed. Manufactured by bonding.

  The cold insulation heat material 1 manufactured as described above is used as a cold insulation material in a state of being cooled or frozen in a refrigeration or freezer, or immersed in hot water, or in some cases, microwave heated in a microwave oven, 2 is used as a heat insulating material in a state where heat is stored. When the cold insulation material 1 is used as a cold insulation material, the cold medium 2 absorbs external heat through the container 3 and cools it. When the cold insulation material 1 is used as a heat insulation material, the heat stored in the cold medium 2 is transmitted to the outside through the container 3 and heated. When the cooling medium 2 absorbs heat or dissipates heat and the cooling or heating ability is reduced, the cold insulation heat material 1 is cooled or heated again and used.

  As the cooling medium 2, a cold insulation heat material 1 in which a granulated or pulverized product of a gelatin crosslinked gel containing crosslinked gelatin and water and a polyurethane base material is filled in a soft container 3 such as a resin bag is used. In this case, since there is no adhesion between the granulated or pulverized products, the entire filling shape can be freely changed without the granulated or pulverized products adhering to each other, and the shape of the heat transfer surface of the cooled portion can be changed. It can be fitted and the heat transfer effect can be increased. In particular, when the cooling medium 2 is used in a frozen state, if the whole is a single gel layer, the whole becomes a hardened layer as a single frozen layer, and cannot be fitted to the shape of the heat transfer surface of the cooled portion. In some cases, by using a granulated or pulverized product of a composite of a gelatin cross-linked gel and a polyurethane base material, the contact surface between the granulated or pulverized products is shifted, so that the entire filling shape of the cooling medium 2 is changed. This makes it possible to fit the shape of the heat transfer surface of the heat-receiving part, and the air layer is interposed between the granulated or pulverized products, so that rapid cooling is alleviated and heat storage is high. Sustainability and heat insulation efficiency are increased. The same effect can be obtained when the container 3 is made of foam.

When the container 3 of the heat insulating material 1 is made of a heat-resistant and microwave-permeable material, even if microwave heating is performed in a microwave oven, the microwave is transmitted through the container 3, so the container 3 is not heated and the cooling medium The water contained in 2 is heated and stored in resonance with the microwave. For this reason, the container 3 made of a microwave permeable material is not deteriorated by heating, and particularly when it is made of a foam made of a microwave permeable material, heating by the microwave is reduced. In particular, the container 3 made of a heat-resistant resin having a melting point of more than 100 ° C. such as polypropylene and polyfluorinated ethylene is less likely to be deteriorated by heat and can be used repeatedly over a long period of time.

  In the embodiment of FIG. 2, the cold insulation heat material 1 is formed by forming a divided cooling medium 2 made of a composite of gelatin crosslinked gel containing crosslinked gelatin and water and a polyurethane base material on the container body 4 of the container 3. It is accommodated in a large number of accommodating portions 4b, and is covered with a lid portion 5 from above to form a pack shape. Adhesive portions 4a are formed between and around the multiple accommodating portions 4b of the container body 4, and portions facing the lid portions 5 are bonded to each other as adhesive portions 5a. The adhesive portions 4a and 5a are further extended to form a belt-like portion 6.

  The cold insulation heat material 1 is made of a material of the container 3, in particular, the bonding portions 4a and 5a made of a soft material, thereby facilitating bending at the bonding portions 4a and 5a, and having a wide heat transfer portion. Even in the case of a hot surface, it can be easily fitted and the heat transfer effect can be enhanced. Further, in this state, it can be tied and fixed by the belt-like portion 6, and usability can be improved. The cooling medium 2 accommodated in the container 3 and other configurations and functions are the same as those in FIG.

  Hereinafter, the present invention will be described by reference examples, examples and comparative examples. In each example,% is% by weight and part is part by weight.

[Reference Examples 1 to 5]:
Gelatin having a molecular weight of 50,000 to 100,000, an isobutene-maleic anhydride copolymer as a crosslinking agent ring-opened with sodium hydroxide to form a sodium salt (number average molecular weight 8,000), antibacterial agent, organic solvent As shown in Table 1, ethanol and water were added in the proportions shown in Table 1 and reacted at room temperature for 24 hours to cause gelation. A gelatin crosslinked gel containing crosslinked gelatin and water was produced, and the jelly strength of the gel after 24 hours was measured. Further, the gelatin cross-linked gel was pulverized by a motor with a rotary blade to obtain a pulverized product having a particle size of about 2 mm. The blending ratio (%) and the results are shown in Table 1. In Table 1, the properties of the pulverized product were determined as follows.
A: There is a sticky feeling between the particles B: There is a wet feeling between the particles C: There is fluidity between the particles (paraple feeling)
D: Good fluidity between particles E: High fluidity between particles

[Examples 1-4, Comparative Examples 1-2]:
The crushed gelatin cross-linked gel of Reference Example 2 and the following polyurethane raw materials are mixed in the proportions shown in Table 2, poured into a mold and allowed to stand to react, whereby the crushed gelatin cross-linked gel and the polyurethane substrate are integrated. A composite molded product was dispersed, and the molded product was pulverized to a particle size of about 3 mm with a motor with a rotary blade to produce a composite pulverized product. Polyurethane raw materials include 75 parts of polymer polyol and 25 parts of polyether polyol as polyhydric alcohol, 0.1 part of amine-based triethylenediamine and 0.2 part of stannous stannous octoate as catalyst, and silicone-based as foam stabilizer 0.5 parts of the dimethylsiloxane modified product, 33 parts of polymeric MDI as the isocyanate, and water attached to the crushed gelatin cross-linked gel as the foaming agent were used. 100 g of the obtained pulverized material was used as a cooling medium 2 and filled in a container 3 made of a polyethylene bag to form a cold insulation material 1.

[Cold insulation test]:
Place the above cold insulation material 1 in a freezer and store it at -5 ° C for 24 hours, then remove it, attach a thermocouple to the surface of the bag, leave it at room temperature (25 ° C), and measure the temperature every 10-20 minutes The temperature difference (increased temperature) of 180 minutes and 0 minutes was calculated. As a comparative example 1, a gelatin crosslinked gel pulverized product of Reference Example 2 was tested, and as a comparative example 2, a commercial product using CMC as a thickener was tested in the same manner. The results are shown in Table 2.

  From Table 2, it can be seen that the samples of Examples 1 to 4 have a lower temperature after 180 minutes and a smaller temperature difference than those of Comparative Example 1, and can be cooled for a long time, and have high heat storage properties. I understand that. It can also be seen that it is not too cold compared to that of Comparative Example 2, the temperature rise is gradual, it can be cooled for a long time, and the heat storage property is high. Between Examples 1-4, it turns out that the ratio of gelatin crosslinked gel is high, and heat storage property is so high that there is much quantity of the water contained. In the test using the gelatin cross-linked gel of other reference examples, almost the same result was obtained.

[Reference Examples 6 to 9]
Gelatin having a molecular weight of 50,000 to 100,000, an isobutene-maleic anhydride copolymer as a crosslinking agent ring-opened with sodium hydroxide to form a sodium salt (number average molecular weight 8,000), antibacterial agent, organic solvent As shown in Table 3, ethanol and water were added in the proportions shown in Table 3 and reacted at room temperature for 24 hours to cause gelation. A gelatin crosslinked gel containing crosslinked gelatin and water was produced, and the jelly strength of the gel after 24 hours was measured. Further, the gelatin cross-linked gel was pulverized by a pulverizer with a rotary blade to obtain a pulverized product having a particle diameter of 3 to 4 mm. Table 3 shows the compounding ratio (%) and the jelly strength.

[Examples 5 to 7]:
The gelatin cross-linked gel pulverized product of Reference Example 8 and the following polyurethane raw materials were mixed in the proportions shown in Table 4, poured into a mold and allowed to stand to react, whereby the gelatin cross-linked gel pulverized product and the polyurethane substrate were integrated. A composite molded product was dispersed, and the molded product was pulverized to a particle size of about 3 mm with a motor with a rotary blade to produce a composite pulverized product. Polyurethane raw materials include 75 parts of polymer polyol and 25 parts of polyether polyol as polyhydric alcohol, 0.09 part of amine-based triethylenediamine and 0.10 parts of stannous stannous octoate as catalyst, and silicone-based as foam stabilizer Dimethylsiloxane modified product of 0.25 parts, polymeric MDI as an isocyanate was 18 parts, and as a foaming agent, water adhered to a crushed gelatin cross-linked gel was used. 100 g of the obtained pulverized product was used as the cooling medium 2 to fill the container 3 of FIG. 1 made of a polypropylene film and a polypropylene foam film to form a cold insulation material 1.

[Cold insulation test]:
Place the above cold insulation material 1 in a freezer and store it at -5 ° C for 24 hours, then take it out and cover the container with a cardboard paper in a U-shape, attach a thermocouple between the container and the cardboard paper, and bring it to room temperature (25 ° C). The temperature was measured every 10 to 30 minutes after standing, and the temperature raising time (minutes) required to raise the temperature from 12 ° C to 15 ° C was measured. The results are shown in Table 4.

[Insulation test]:
After heating the above-mentioned cold insulation material 1 in a microwave oven for 1.5 minutes, it is taken out and the container is covered with a corrugated paper in a U shape, and a thermocouple is attached between the container and the corrugated paper, and the room temperature (25 ° C.) is reached. The temperature was measured every 10 to 30 minutes after standing, and the temperature drop time (minutes) required to drop the temperature from 70 ° C to 40 ° C was measured. The results are shown in Table 5.

  From Table 4 and Table 5, it can be seen that the cold insulation heat materials of Examples 5 to 7 maintain the cold insulation and heat insulation effects for a long time and have high heat storage properties. Here, the heat insulating material made of a composite material having a high ratio of gelatin cross-linked gel and containing a large amount of water has a higher heat storage property, and in particular, a heat insulating material made of a composite material having a gelatin cross-linked gel of 70% is excellent in cold storage, It turns out that it has a heat retention effect. In the test using the gelatin cross-linked gel of other reference examples, almost the same result was obtained.

  The present invention can be used as a cold medium used for cooling or heating by storing heat, and a gelatin-crosslinked gel-polyurethane type cold insulation material for keeping cold or keeping warm with this cold medium.

DESCRIPTION OF SYMBOLS 1 Cold insulation heat material 2 Cooling medium 3 Container 4 Container main body 4a, 5a Adhesion part 4b Storage part 5 Cover part 6 Strip | belt-shaped part

Claims (10)

  A cold medium comprising a composite of a gelatin crosslinked gel comprising crosslinked gelatin and water and a polyurethane substrate.   A cold medium comprising a granulated or pulverized product comprising a composite of a gelatin crosslinked gel containing crosslinked gelatin and water and a polyurethane substrate. 3. The cooling medium according to claim 1 or 2, wherein the composite contains a reaction product of a raw material mixture containing a granulated or pulverized product of gelatin cross-linked gel containing cross-linked gelatin and water and a polyurethane raw material containing polyol and polyisocyanate.   4. The cooling medium according to any one of claims 1 to 3, wherein the gelatin crosslinked gel contains 2 to 60% by weight of crosslinked gelatin and 40 to 98% by weight of water, and has a jelly strength of 9 to 3000 g. 5. The reaction product of an aqueous sol according to claim 1, wherein the gelatin cross-linked gel comprises 2 to 59% by weight of gelatin, 1 to 20% by weight of a cross-linking agent and 40 to 97% by weight of water, and has a jelly strength of 9 A cold medium that is ~ 3000g.   6. The cooling medium according to claim 1, wherein the polyurethane base material is a polyurethane foam. Gelatin cross-linked gel according to any of claims 1 to 6,
A reaction product of a raw material mixture containing a polyol, a polyisocyanate and a polyurethane raw material containing a blowing agent, or a cold medium containing a granulated or pulverized product thereof.   A cold insulation heat material in which the cold medium according to any one of claims 1 to 7 is accommodated in a container. A cold insulation heat material in which the cold medium according to any one of claims 1 to 7 is housed in a soft container .   The cold insulation heat material according to claim 8 or 9, wherein the container is a heat-resistant and microwave-permeable container.

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