JP2010168538A - Endothermic/exothermic capsule and endothermic/exothermic capsule dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endothermic/exothermic capsule destroying less microencapsulating wall upon swelling/shrinkage of a phase transfer material accompanied by endotherm/exotherm of the endothermic/exothermic capsule and showing high dispersion stability in a highly safe fluorinated solvent; an endothermic/exothermic capsule dispersion; and a method for producing the same. <P>SOLUTION: The endothermic/exothermic capsule includes a water-curable urethane monomer or urethane prepolymer and a fluorinated polymer having a hydroxy group in its molecule as materials for a film-like capsule wall forming an enclosed space therein, and further includes at least one of sugar alcohol, urea and thiourea as materials enclosed in the closed space inside of the capsule wall. The endothermic/exothermic capsule is produced by a first stage of microencapsulation wherein an encapsulating wall is formed by means of a quick-curable urethane monomer or urethane prepolymer in the coexistence of a surfactant, and a subsequent second stage of microencapsulation wherein a further encapsulating wall is formed by means of a urethane monomer or urethane prepolymer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an absorption / radiation capsule, an absorption / radiation capsule dispersion, and a method for producing the same.

  A microcapsule of a phase change material that dissolves in solvent water is described in Japanese Patent Application Laid-Open No. 2001-181612 (Patent Document 1). In this patent document, an inorganic salt hydrate such as sodium sulfate decahydrate or calcium chloride hexahydrate is used as a phase transition material in a solution containing a vinyl monomer that is a capsule wall forming material, a polymerization initiator, and a dispersant. Disperse to obtain a W / O emulsion in which a phase transition material dissolved in a solvent water is dispersed in a capsule wall-forming substance solution. The W / O emulsion is dispersed in an aqueous solution containing a dispersant, and W / O / By preparing a W-based emulsion and polymerizing the capsule wall-forming substance, an absorbing / dissipating capsule and an absorbing / dissipating capsule dispersion provided with phase change substances interspersed with the capsule wall-forming substance are obtained.

  In Japanese Patent Application Laid-Open No. 2007-031597 (Patent Document 2), barium hydroxide octahydrate (melting point: 78 ° C.) as a phase transition material, perfluorocarbon (trade name “Fluorinert FC3255”, manufactured by Sumitomo 3M) as a fluorine-based solvent, and After preparing an emulsified dispersion using a high-pressure emulsifier at a temperature (85 ° C.) above the melting point of the phase change material with a fluorosurfactant (trade name “Furgent 150”, manufactured by Neos), microencapsulation A styrene monomer, a divinylbenzene monomer, and 4,4-azobis-4-cyanovaleric acid (trade name “AVCC”, manufactured by Otsuka Chemical Co., Ltd.), which is a polymerization initiator, are added under stirring of the dispersion, and a phase is added. A film-like capsule wall body that forms a sealed space inside by polymerizing vinyl monomer at the interface of the transfer material particles, and the sealed space of the capsule wall body Newsletter intake and radiator capsules and intake and radiator capsule dispersion with the incoming has been phase change material.

  In JP-A-2005-203148 (Patent Document 3), barium hydroxide octahydrate (melting point: 78 ° C.) particles as a phase transition material are dispersed in fluorine oil (perfluorocarbon), and a silane coupling agent is added to the dispersion. After adding and adsorbing the silane coupling agent to the interface of the barium hydroxide octahydrate particles of the phase change material which is inorganic particles, the temperature of the dispersion is brought to about 55 ° C. A silane coupling agent at the particle interface is polymerized to obtain an absorption / radiation capsule and an absorption / radiation capsule dispersion in a fluorine-based solvent.

  In Japanese Patent Application Laid-Open No. 2007-330872 (Patent Document 4), an inorganic salt hydrate (barium hydroxide octahydrate, sodium acetate trihydrate) is used as a phase transition material, and water added to the inorganic salt hydrate is added. As an initiator, a microcapsule wall is formed at the interface of a water curable urethane monomer or urethane prepolymer and an inorganic salt hydrate as a phase transition material, and the absorption / radiation capsule is placed in an absorption / radiation capsule and a water-insoluble solvent. A dispersed absorption / radiation capsule dispersion is obtained.

  In Japanese Patent Application Laid-Open No. 2007-244935 (Patent Document 5), water-insoluble paraffin wax, saturated fatty acid, and unsaturated fatty acid as a phase change material (latent heat storage material) are dispersed in water, and an amine-based polymerizable reactive material is added. Add an aqueous alkaline solution to form a nylon film at the phase change material particle interface, and then form an O / W emulsion made of a dispersion of several nm to 10 μm containing a polymerizable reactive material having an isocyanate group or a double bond. By adding it to cause interfacial polymerization or radical polymerization reaction, a polymer film is formed on the surface of the nylon film, and an absorbing / dissipating capsule is obtained.

  In JP-A-2008-221046 (Patent Document 6), water-insoluble hexadecane as a phase change material (phase change material) is heated and dispersed in a formaldehyde aqueous solution of melamine powder to thereby form an outer shell made of melamine resin (151 nm˜ 300 nm thickness), and then coated with a reactive substance such as polyvinyl alcohol to obtain an absorption / heat dissipation capsule.

JP 2001-181612 A JP 2007-031597 A JP-A-2005-203148 JP 2007-330876 A JP 2007-244935 A JP 2008-221046 A

  The absorbent / heat-dissipating capsule having the characteristics described in Patent Document 1 is obtained by dispersing droplets of a phase change material dissolved in solvent water in oil composed of a monomer or the like as an encapsulating agent. Since the O / W emulsion is dispersed in the solvent water after the formation, the volume fraction of the phase change material in the entire capsule cannot be more than the close-packed state of the phase change material droplets. It is difficult to make the ratio of the volume fraction of the phase change material with respect to the total volume substantially 60% by volume or more.

  In addition, since the O / W emulsion is dispersed once in the solvent water after the O / W emulsion is formed, there is a problem that the particle size of the capsule is larger than the particle size of the droplet of the phase change material. .

  The absorption / radiation capsule having the characteristics described in Patent Document 2 uses barium hydroxide octahydrate or strontium hydroxide octahydrate, which are inorganic salt hydrates, as the phase transition material. When the capsule wall is destroyed, barium hydroxide and strontium hydroxide, which are deleterious substances, are eluted. In addition, the inorganic salt hydrate as a phase transition material has a problem that the water of hydration is eliminated by repeated melting and solidification, and the melting and solidification cannot be performed stably.

  In addition, after obtaining inorganic salt hydrate particles as a phase transition material, a vinyl monomer and a radical polymerization initiator as an encapsulating agent are added, and the encapsulating agent is polymerized at the interface between the inorganic hydrate particles and the dispersion medium. Although the reaction is proceeding, there is a possibility that the polymerization reaction of the encapsulating agent may occur at a place other than the interface between the inorganic hydrate particles and the dispersion medium, resulting in the generation of capsule particles containing no phase change material. Have.

  The absorption / heat dissipation capsule having the characteristics described in Patent Document 3 uses barium hydroxide octahydrate which is an inorganic salt hydrate as a phase transition material, and water contained in the phase transition material by a silane coupling agent. The polymerization reaction of the encapsulating agent can proceed only at the interface between the inorganic hydrate particles and the dispersion medium, but alcohol such as ethanol is generated by the polymerization of the silane coupling agent. For this reason, there is a problem that the dispersibility of the absorbing / dissipating capsule is significantly lowered by the action of the generated alcohol.

  The absorption / heat dissipation capsule having the characteristics described in Patent Document 4 improves the problems of Patent Documents 1 to 3, but is an inorganic salt water as a phase change material with a water-curable urethane monomer or urethane prepolymer. When the microcapsule wall is formed at the interface of the Japanese product, the microencapsulation wall is not elastic, and the microencapsulation wall is torn due to the expansion / contraction of the phase change material due to the absorption / dissipation of the phase change material. Has drawbacks.

  In addition, microencapsulated particles formed with water-curable urethane monomer or urethane prepolymer have organic walls, so there is no problem when absorbing and dissipating capsule dispersion liquid by dispersing in organic solvent, but flammability In the case of dispersing in a fluorinated solvent that does not have any, there is a problem that the affinity between the microencapsulation wall and the fluorinated solvent is weak, and the stability of the absorbing / dissipating capsule dispersion is deteriorated.

  The manufacturing method of the absorption / radiation capsule having the characteristics described in Patent Documents 5 and 6 is a method in which a water-insoluble phase transition material is microencapsulated in two stages in a water-soluble solvent. When the transfer substance is a water-soluble substance such as sugar alcohol, urea, thiourea, etc., the above method cannot form a microencapsulated wall.

  The present invention has been made in view of the circumstances as described above, and uses a highly safe phase change material, which can sufficiently withstand the expansion and contraction of a water-soluble phase change material during repeated melting and solidification. An object of the present invention is to provide an absorbing / dissipating capsule dispersion liquid having high dispersion stability when dispersed in a fluorine-based solvent and an absorbing / dissipating capsule having an encapsulating wall.

  The inventors of the present invention have intensively studied to achieve the above object. As a result, the present inventor conducted extensive research while paying attention to the current state of the prior art, and as a result, the membrane-like capsule wall forming an enclosed space inside, and the sealed space of the capsule wall were enclosed. An absorption / radiation capsule comprising a phase change material dissolved in water or a water-miscible organic solvent as an encapsulated material, wherein the encapsulated material is a phase transition comprising at least one of sugar alcohol, urea, and thiourea By using a phase transition material with high safety by containing a substance, by containing a water-curable urethane monomer or urethane prepolymer and a fluorine-based polymer having a hydroxyl group in the molecule as the capsule wall, Absorption / radiation capsules with microencapsulated walls that can withstand the expansion and contraction of phase change materials, and absorption / radiation with high dispersion stability when dispersed in fluorinated solvents After the formation of an encapsulated wall in the presence of a surfactant with a urethane monomer or urethane prepolymer having a high curing speed as a first-stage microencapsulation, a urethane monomer is obtained as a second-stage microencapsulation. Alternatively, the inventors have found that the above-described absorption / heat dissipation capsule can be produced by forming a further encapsulating wall with a urethane prepolymer, and have completed the present invention.

That is, the present invention relates to the following absorbing / dissipating capsule, absorbing / dissipating capsule dispersion, and manufacturing method thereof.
(1) A membrane-like capsule wall that forms a sealed space inside, and a phase change material that dissolves in water or a water-miscible organic solvent as a sealed material sealed in the sealed space of the capsule wall A heat-absorbing / heat-dissipating capsule comprising the phase-change material comprising at least one of sugar alcohol, urea and thiourea as the encapsulating material, A heat-absorbing and heat-dissipating capsule comprising a functional urethane monomer or urethane prepolymer and a fluorine-based polymer having a hydroxyl group in the molecule.
(2) The mass ratio of the water-curable urethane monomer or urethane prepolymer of the capsule wall body to the fluorine-based polymer having a hydroxyl group in the molecule is 40/60 to 60/40 ).
(3) The absorbing / dissipating capsule according to (1) or (2), wherein the encapsulating substance contains water or a polyhydric alcohol.
(4) The absorbing / dissipating capsule according to (3), wherein the polyhydric alcohol is composed of at least one of ethylene glycol, diethylene glycol, and glycerin.
(5) The above-mentioned (1), wherein the absorption / heat dissipation capsule has a particle diameter of 10 to 50 μm, and the ratio of the capsule wall thickness to the absorption / heat dissipation capsule particle diameter is 2 to 10%. ) To (4).
(6) An absorbent / heat dissipating capsule dispersion comprising the fluorine-based dispersion medium and the absorbing / dissipating capsule according to any one of (1) to (5) dispersed in the dispersion medium.
(7) The absorption / heat dissipation capsule dispersion according to (6), wherein the phase change material is 10 to 40% by mass with respect to the dispersion, and the fluorosurfactant is 2% with respect to the phase change material. The absorbing / dissipating capsule dispersion described above, which contains ˜30% by mass and a glycol-based glidant in an amount of 10 to 100% by mass with respect to the phase change material.
(8) The method for producing an absorption / radiation capsule according to any one of (1) to (5) above, wherein the surfactant is made of a urethane monomer or urethane prepolymer having a high curing rate as the first-stage microencapsulation. The method as described above, wherein after forming the encapsulated wall in the coexistence, a further encapsulated wall is formed by urethane monomer or urethane prepolymer as the second-stage microencapsulation.
(9) When forming the encapsulation wall with a urethane monomer or urethane prepolymer having a high curing speed as the first-stage microencapsulation, 2 to 50% by mass of a surfactant is contained with respect to the phase change material. The method for producing an absorption / radiation capsule according to (8), characterized in that:

  The absorbing / dissipating capsule described in (1) above does not use a strong basic deleterious substance such as barium hydroxide octahydrate or strontium hydroxide octahydrate as a phase transition material, and absorbs / releases heat. When the capsule is broken, the deleterious substances do not elute in the dispersion. In addition, since inorganic salt hydrates with low stability of repeated melting and solidification due to the detachment of hydrated water are not used as phase transition materials, it is possible to obtain absorption / heat dissipation capsules with high durability against repeated melting and solidification. . Further, by containing a water-curable urethane monomer or urethane prepolymer and a fluorine-based polymer having a hydroxyl group in the molecule as the capsule wall body, elasticity is generated in the microencapsulated wall, It is possible to obtain an absorbing / dissipating capsule that can withstand the expansion / contraction of the phase change material accompanying the absorption / dissipation of the phase change material and that does not break the microencapsulated wall.

  According to the absorption / heat dissipation capsule described in (2), the mass ratio of the water-curable urethane monomer or urethane prepolymer and the fluorine-based polymer having a hydroxyl group in the molecule is controlled from 40/60 to 60/40. As a result, the microencapsulated wall can be made more elastic, and the microencapsulated wall contains a fluorine-based polymer, so that the affinity between the microencapsulated wall and the fluorine-based solvent is improved.

  According to the absorption / heat dissipation capsule described in (3) above, the interface between the phase change material and the urethane monomer or urethane polymer solution in which the phase change material is dispersed by containing water or a polyhydric alcohol as the encapsulating material. Since the polymerization reaction continues, it is possible to obtain a heat-absorbing and heat-dissipating capsule that is reliably microencapsulated. When water is contained as the encapsulating material, water and the urethane monomer or urethane polymer having an isocyanate group react at the interface between the phase change material and the urethane monomer or urethane polymer solution in which the phase change material is dispersed. Since the terminal of the urethane polymer becomes an amine and the terminal reacts with another urethane monomer or urethane polymer, the polymerization reaction continues at the interface. In addition, since water having a low molecular weight can quickly move from the inside of the phase change material to the interface during the polymerization reaction, the polymerization reaction continues at the interface, and it is possible to reliably obtain microcapsulated absorption / heat dissipation capsules. it can. When polyhydric alcohols are contained as the encapsulating substance, the urethane monomer or urethane polymer having an alcohol group and an isocyanate group reacts at the interface between the phase change substance and the urethane monomer or urethane polymer solution in which the phase change substance is dispersed, Since the terminal of the urethane monomer or urethane polymer becomes a hydroxyl group and the terminal reacts with another urethane monomer or urethane polymer, the polymerization reaction continues at the interface.

  According to the capsule for absorbing and releasing heat described in the above (4), as the encapsulating substance, polyhydric alcohols having a low molecular weight, such as ethylene glycol, diethylene glycol or glycerin, are contained in the capsule quickly during the polymerization reaction. Since it can move from the inside of the phase change material to the interface, the polymerization reaction continues at the interface, and a microcapsulated absorption / heat dissipation capsule can be obtained.

  According to the absorption / radiation capsule described in (5) above, since the particle diameter of the absorption / radiation capsule is 10 to 50 μm, the absorption / radiation capsule enters the gap of the mechanical seal of the pump that transfers the absorption / radiation capsule dispersion liquid. Absorptive and heat dissipation capsule can be obtained. Further, since the ratio of the capsule wall thickness to the particle diameter of the absorbing / dissipating capsule is 2 to 10%, it withstands the expansion / contraction of the phase change material accompanying the absorption / dissipation of the phase change material in the microencapsulated wall. In addition, it is possible to obtain a heat-absorbing and heat-dissipating capsule with little destruction of the microencapsulated wall.

  According to the absorbent / heat dissipation capsule dispersion described in (6) above, since the non-flammable fluorine-based dispersion medium is used as the dispersion medium, it is possible to obtain an absorbent / heat dissipation capsule dispersion without flammability. In addition, since the microencapsulated wall contains a fluorinated polymer, the affinity between the microencapsulated wall and the fluorinated solvent is improved, and an absorbing / dissipating capsule dispersion having high dispersion stability in the fluorinated solvent is obtained. be able to.

  According to the absorbing / dissipating capsule dispersion described in (7) above, the phase change material in the absorbing / dissipating capsule is 10 to 40% by mass with respect to the dispersion, and the fluorosurfactant is used as the phase change material. In contrast, by containing 2 to 30% by mass of the glycol-based glidant in an amount of 10 to 100% by mass with respect to the phase change material, aggregation of the microencapsulated water-soluble phase change material particles is prevented, and the water-soluble phase change material is obtained. A dispersion of a fluorine-based solvent of a microencapsulated water-soluble phase change material stabilized with less sedimentation of particles can be obtained.

  According to the method for producing a heat-absorbing / heat-radiating capsule described in (8) above, the ratio of the capsule wall thickness to the particle diameter of the heat-absorbing / heat-radiating capsule can be 2 to 10%. It is possible to provide an absorbing / dissipating capsule that can withstand expansion and contraction of the phase change material accompanying absorption / dissipation of the phase change material, and that does not break the microencapsulated wall.

  According to the method for producing a heat-absorbing / radiating capsule described in (9) above, when forming an encapsulated wall with a urethane monomer or urethane prepolymer having a high curing rate, 2 to 50% by mass with respect to the phase change material. Since the surfactant is contained, it is possible to provide an absorbing / dissipating capsule with less coalescence of the absorbing / dissipating capsule.

  According to the present invention, the microencapsulation wall is less damaged by the expansion / contraction of the phase change material accompanying the absorption / dissipation of the absorption / radiation capsule, and the absorption stability is high in a highly safe fluorinated solvent. A heat dissipation capsule, a heat absorption / heat dissipation capsule dispersion, and a method for producing the same can be provided.

It is an optical micrograph of the absorption-heat radiation capsule obtained in Example 7 of this invention.

One embodiment of the present invention will be described as follows.
The water curable urethane monomer or urethane prepolymer is not particularly limited as long as it has an isocyanate group at the terminal and reacts with water to cause a polymerization reaction, but a tolylene diisocyanate (TDI) monomer. Alternatively, prepolymer, diphenylmethane diisocyanate (MDI) monomer or prepolymer, hexamethylene diisocyanate (HDI) monomer or prepolymer, 1,3-bis (isocyanatomethyl) cyclohexane (H ₆ XDI) monomer or prepolymer A polymer can be illustrated. These can be used alone or in combination.

Commercially available water-curing urethane monomers include Mitsui Chemicals polyurethane Cosmonate T65, T80, T100 (TDI), Cosmonate PH, M50, 100, 200, 300 (MDI), Takenate 700 (HDI) ), Takenate 500 (XDI series), Takenate 600 (H ₆ XDI series).

Commercially available water-curing urethane prepolymers include Olester M83-42MBP, M37-33J, M37-50SS, M75-50SS, Takenate M-417BA, M-408, M-402 (TDI) manufactured by Mitsui Chemicals Polyurethane. System), Takenate M405-BA (MDI system), Takenate M-631N (HDI system), Takenate M-605N (H ₆ XDI system).

  Among the above, as the urethane monomer or urethane prepolymer having a high curing rate used for the first-stage microencapsulation, a urethane monomer or prepolymer having a curing time of 2 hours or less at room temperature (25 ° C.) and humidity of 60% is used. Preferably, examples of commercially available water-curable urethane prepolymers include Olester M83-42MBP, M37-33J, M37-50SS, M75-50SS, Takenate M-417BA, and M-408.

  Among the above, the curing rate of the urethane monomer or urethane prepolymer used for the second-stage microencapsulation is not particularly limited, but in general, the curing time is 3 hours or less at room temperature (25 ° C.) and 60% humidity. A urethane monomer or prepolymer having a hydrogen atom is preferred, and examples of commercially available water-curable urethane prepolymers include Takenate M-402, M-405-BA, M-631N, and M-605N.

  The fluoropolymer used as the microencapsulating agent constituting the capsule wall in the present invention is particularly limited as long as it has a hydroxyl group in the molecule and at least one fluorine atom is bonded to the carbon skeleton. Not done.

  The fluorine-based polymer having a hydroxyl group in the molecule used in the present invention can be produced, for example, by copolymerization using a fluorine-based vinyl monomer having a hydroxyl group and a vinyl monomer having no hydroxyl group.

Examples of the fluorine-based vinyl monomer having a hydroxyl group include CX ₂ = CX ¹ —Rf—CH ₂ OH. Wherein X, X ¹ are the same or different, a hydrogen atom or a fluorine atom, Rf is a divalent fluorine-containing alkylene group, a fluorine-containing oxyalkylene group having 1 to 40 carbon atoms of 1 to 40 carbon atoms, carbon atoms 1 to 40 A fluorine-containing alkylene group containing an ether bond or a fluorine-containing oxyalkylene group containing an ether bond having 1 to 40 carbon atoms.

More specifically, the fluorine-based vinyl monomer having a hydroxyl group is CF ₂ ═CF—Rf ¹ —CH ₂ OH.
Can be mentioned. Wherein, Rf ¹ is a divalent fluorine-containing alkylene group or ORf ² of 1 to 40 carbon atoms, provided that, Rf ² is a divalent fluorine-containing alkylene group or an ether bond having 1 to 40 carbon atoms of 1 to 40 carbon atoms Is a divalent fluorine-containing alkylene group.

CF ₂ = CFCF ₂ —ORf ³ —CH ₂ OH
Can be mentioned. In the formula, -Rf ³ represents a divalent fluorinated alkylene group having 1 to 39 carbon atoms or a divalent fluorinated alkylene group containing an ether bond having 1 to 39 carbon atoms.

In ^{_{addition, CH 2 = CFCF 2 -Rf 4}} -CH 2 OH
Can be mentioned. In the formula, -Rf ⁴ is a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms, or ORf ⁵ (Rf ⁵ is a divalent fluorine-containing alkylene group having 1 to 39 carbon atoms or an ether bond having 1 to 39 carbon atoms. Represents a divalent fluorine-containing alkylene group).

In ^{_{addition, CH 2 = CH-Rf 6}} -CH 2 OH
Can be mentioned. In the formula, Rf ⁶ is a divalent fluorine-containing alkylene group having 1 to 40 carbon atoms.

On the other hand, as vinyl monomers having no hydroxyl group, fluorine-based vinyl monomers such as tetrafluoroethylene, chlorotrifluoroethylene, vinyl fluoride, vinylidene fluoride, hexafluoropropylene, hexafluoroisobutene, perfluoro (alkyl vinyl ether) s CH ₂ ═CF— (CF ₂ ) _n —X, CH ₂ ═CH— (CF ₂ ) _n —X, wherein X is a hydrogen atom, chlorine atom or fluorine atom, and n is 1 to An integer of 5).

  As the fluorine-based polymer having a hydroxyl group in the molecule, a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether is preferable.

  The fluorine-based polymer having a hydroxyl group in the molecule used in the present invention can also be produced by copolymerization using a fluorine-based vinyl monomer having no majority hydroxyl group and a vinyl monomer having a small amount of hydroxyl group. .

  Examples of the fluorine-based vinyl monomer having no hydroxyl group include fluoroolefins such as tetrafluoroethylene, trifluoroethylene, and chlorotrifluoroethylene.

  Examples of the vinyl monomer having a hydroxyl group include hydroxyalkyl vinyl ethers. Hydroxyalkyl vinyl ether is an alkyl vinyl ether containing a substituted hydroxyl group on the alkyl chain. Examples of the alkyl vinyl ether include linear or branched aliphatic alkyl vinyl ethers having 3 to 8 carbon atoms such as methyl vinyl ether, ethyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, and similar lower alkyl vinyl ethers.

  As the fluorine-based polymer having a hydroxyl group in the molecule, a copolymer of hydroxyalkyl vinyl ether and fluoroolefin is preferable. Similarly, a fluoropolymer containing a terpolymer of alkyl vinyl ether, hydroxyalkyl vinyl ether, and fluoroolefin ether is also preferred. The fluorocopolymer or terpolymer may contain 30% to 70% fluoroolefin and 30% to 70% vinyl ether units containing hydroxyalkyl vinyl ether units on a mole percent basis. The hydroxyalkyl vinyl ether unit usually constitutes 1 mol% to 30 mol% of the fluoropolymer having a hydroxyl group in the molecule. The hydroxyl value of the fluorine-based polymer having a hydroxyl group in the molecule is usually 2 to 200, preferably 5 to 150. Suitable fluoropolymers having a hydroxyl group in the molecule are terpolymers of alkyl vinyl ethers, hydroxyalkyl vinyl ethers and trifluoroethylene, and commercially available copolymers known as Lumiflon polymers.

  U.S. Pat. No. 4,916,188 discloses that a fluorine-based polymer having a hydroxyl group in the molecule is 45% to 48% fluorine-based monomer, 1% to 30%, preferably 2% to 5% based on mol%. It is stated that hydroxyalkyl vinyl ether monomers and those containing the remaining amount of alkyl vinyl ether monomers are preferred. This fluoropolymer is solid at ambient temperature and has a softening point or Tg greater than about 35 ° C, preferably 35 ° C to 50 ° C, according to ASTM D 3016, D 3536-76 and D 3593-80. It has a number average molecular weight measured by GPC (gel permeation chromatography) of 8,000 to 16,000, preferably 10,000 to 14,000. Such types of fluoropolymers are also suitable for use in the present invention. Such a polymer is called Lumiflon LF-200D and is sold by Asahi Glass Co., Ltd.

  The fluorine-based polymer having a hydroxyl group in the molecule is generally a number average molecular weight of about 8,000 to about 16,000, preferably about 9,000 to about 13,000, more preferably about 10,000 to about 11,000. Have

  A preferred fluoropolymer having a hydroxyl group in the molecule used in the present invention is Lumiflon LF-710F manufactured by Asahi Glass Co., Ltd. Lumiflon LF-710F has a hydroxyl value of 46 ± 5, Tg 55, an average molecular weight of 10,000, and a melting point of 100 ° C. Lumiflon LF-710F has an alternating arrangement of carbon and fluorine and exhibits excellent weather resistance. Such polymers have both hydroxyl and carboxyl groups.

  The fluorine-based polymer can be used alone or in combination, but in order to enhance the effect of adding the fluorine-based surfactant, among the microencapsulating agents constituting the capsule wall body, the amount of the fluorine-based polymer is adjusted. It is preferable to set it as 10 mass%-90 mass%, and it is more preferable to set it as 30 mass%-70 mass%. The mass ratio of the water-curable urethane monomer or urethane prepolymer and the fluoropolymer having a hydroxyl group in the molecule is preferably 40/60 to 60/40, and more preferably 45/55 to 55/45 preferable.

  The fluorinated solvent used as the fluorinated dispersion medium in the absorption / heat dissipation capsule dispersion of the present invention is not particularly limited as long as it is a solvent in which at least one fluorine atom is bonded to the carbon skeleton. Examples thereof include perfluoropolyether, perfluorocarbon, and hydrofluoroether. These fluorinated solvents may be used alone or in combination. Fluorine-based solvents do not cause a decrease in the melting temperature of phase transition materials dissolved in water or water-miscible organic solvents, and the absorption / radiation capsule dispersion has characteristics that are not flammable. Preferred as a capsule dispersion.

  The phase change material (hereinafter referred to as “water-soluble phase change material”) dissolved in water or a water-miscible organic solvent in the present invention is not particularly limited as long as it is any of sugar alcohol, urea, and thiourea. Examples thereof include sugar alcohols such as erythritol, threitol, xylitol, sorbitol, maltitol and the like.

  The water-miscible organic solvent that dissolves the phase change material is not particularly limited as long as it is a solvent that dissolves the sugar alcohol, urea, and thiourea that are the phase change materials, and monohydric alcohols (methanol, ethanol, propanol, butanol). Etc.), polyhydric alcohols (ethylene glycol, diethylene glycol, glycerin, etc.), ketones (acetone, methyl ethyl ketone, diethyl ketone, etc.) and esters (methyl acetate, ethyl acetate, etc.).

  These water-soluble phase change materials can be used alone or in combination. Moreover, in order to adjust a melting point, the substance which melt | dissolves in water or a phase change substance may be included. The substance that dissolves in the phase transition material is not particularly limited as long as it has a melting temperature lower than that of the phase transition material and dissolves in the phase transition material at a temperature higher than the phase transition temperature, but monohydric alcohols (methanol, ethanol, propanol) And butanol), polyhydric alcohols (ethylene glycol, diethylene glycol, glycerin, etc.), ketones (acetone, methyl ethyl ketone, diethyl ketone, etc.) and esters (methyl acetate, ethyl acetate, etc.).

  It is preferable to add water or a polyhydric alcohol to the water-soluble phase change material as an encapsulating material that serves as an initiator for the microencapsulation reaction. The polyhydric alcohol is not particularly limited as long as it is a dihydric or higher alcohol and can be dissolved in the phase change material at a temperature higher than the phase transition temperature. In order to react with the monomer or prepolymer, the molecular weight is preferably not large, and examples thereof include ethylene glycol, diethylene glycol and glycerin.

  The amount of water or polyhydric alcohols used as an initiator for the microencapsulation reaction added to the water-soluble phase change material is preferably 1% by mass to 20% by mass with respect to the phase change material, and 5% by mass to 15% by mass. % Is more preferable. When the amount is less than 1% by mass, the effect of adjusting the melting temperature and the effect of the polymerization initiator are not exerted. When the amount exceeds 20% by mass, the content of the phase change material, which is an effective material for absorbing and releasing heat, is preferably reduced. Absent.

  The supercooling inhibitor that adjusts the solidification temperature of the phase change material, which is a material that adjusts the phase transition temperature of the phase change material, has a melting temperature higher than the melting temperature of the phase change material, The substance is not particularly limited as long as it can be a seed crystal.

  Examples of the supercooling preventive agent include inorganic salts, metal oxides, metals, and organic substances.

  The inorganic salt is not particularly limited as long as it has a melting temperature higher than the melting temperature of the phase change material, and examples thereof include sodium chloride, potassium chloride, potassium bromide, magnesium chloride, sodium carbonate, and borax.

  Examples of the metal oxide include fine particles such as copper oxide, silver oxide, zinc oxide, nickel oxide, alumina, titania, silica, and zirconia.

  Examples of the metal include fine particles such as platinum, gold, silver, palladium, iridium, ruthenium, and nickel.

  Examples of organic substances include mannitol and pentaerythritol.

  These supercooling inhibitors may be used alone or in combination of two or more. Further, when the supercooling of the phase change material is not large, it may not be used. The content of the supercooling inhibitor with respect to the phase change material is preferably 0.1% by mass to 10% by mass. When the amount is less than 0.1% by mass, the effect of preventing overcooling is not exhibited, and when it exceeds 10% by mass, the content of the phase change material, which is an effective substance for absorbing and releasing heat, is undesirably reduced.

  The dispersion medium may contain a surfactant in order to improve the dispersibility of the absorbing / dissipating capsule. The surfactant in the present invention is not particularly limited, but various known nonionic surfactants, anionic surfactants, and cationic surfactants can be exemplified. Moreover, the surfactant to be used may be one kind or a combination of two or more kinds.

  Nonionic surfactants include sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene polyoxypropylene A block polymer etc. can be illustrated.

  Examples of the anionic surfactant include alkylbenzene sulfonate, alkyl sulfate, rosin soap, polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene alkylphenyl ether sulfonate, polyoxyethylene alkylphenyl ether sulfosuccinic acid. Examples thereof include salts, polyoxyethylene distyryl phenyl ether sulfate, sulfosuccinate of polyoxyethylene distyryl phenyl ether, and the like.

  Examples of the cationic surfactant include alkyl trimethyl ammonium chloride and reverse soap.

  As the surfactant to be dispersed in the fluorinated medium, the nonionic surfactant is polyoxyethylene ether of hexafluoropropene oligomer, and the anionic surfactant is sulfonate or phosphonate of hexafluoropropene oligomer. In the case of carboxylate and cationic surfactant, hexafluoropropene oligomer is preferable.

  Preferred fluorine-based surfactants used in the present invention are KB-L110, KB-L109 and KB-L115 manufactured by Neos Co., Ltd.

  From the viewpoint of the safety of the heat-absorbing and heat-dissipating capsule dispersion, from the viewpoint of the safety of the fluorine-based solvent dispersion, the glycol-type flow promoter to be added preferably has a high flash point. From this viewpoint, ethylene glycol, diethylene glycol Preferred are ethers or esters of triethylene glycol.

  From the viewpoint of the stability of the heat-absorbing / radiating capsule dispersion, the glycol type glidant to be added is diethylene glycol monoethyl ether acetate (DEG-MEEA), diethylene glycol monobutyl ether acetate (DEG MBuEA) and triethylene glycol dimethyl ether (TEG-DME) are particularly preferred.

  When the microcapsule wall is formed on the surface of the phase change material particles, the method of dispersing the melted phase change material in a solvent containing a water-curable urethane monomer or urethane prepolymer forms phase change material microparticles. Although it will not specifically limit if it can be performed, In order to obtain a fine phase change material particle, the emulsification dispersion | distribution method by a homomixer or a high-pressure emulsifier, or the film | membrane emulsifier is preferable.

  The solvent that dissolves the urethane monomer or urethane prepolymer is a solvent that dissolves the urethane monomer or prepolymer and hardly dissolves the phase change material, and is not particularly limited as long as it has a boiling point equal to or higher than the melting point of the phase change material. And hydrocarbon solvents such as toluene, xylene, ethylbenzene, nonane, decane, and dodecane.

  When the phase change material is dispersed in a solvent containing a water curable urethane monomer or urethane prepolymer, it is necessary to add a surfactant that lowers the interface tension of the phase change material interface and stabilizes the phase change material particles. However, in order to reduce the particle size of the phase change material particles by coalescence of the phase change material particles, it is preferably 2 to 50% by mass, more preferably 5 to 20% by mass, based on the phase change material. The surfactant is contained at the time of microencapsulation in the first stage.

  The particle diameter of the absorbing / dissipating capsule is small from the viewpoint of the stability of the dispersion, and is preferably several tens of μm or more from the viewpoint of not entering the gap of the mechanical seal of the pump that transfers the absorbing / dissipating capsule dispersion. From both viewpoints, the particle diameter of the absorbing / dissipating capsule is preferably selected to be 10 to 50 μm, more preferably 15 to 30 μm.

  The thickness of the capsule wall of the absorbing / dissipating capsule is preferably thicker from the viewpoint of the strength of the absorbing / dissipating capsule, and is preferably thinner from the viewpoint of containing a large amount of phase change material in the capsule. From both viewpoints, the ratio of the thickness of the capsule wall body to the diameter of the absorbing / dissipating capsule is preferably 2 to 10%, more preferably 5 to 10%.

  In order to produce an absorption / radiation capsule in which the ratio of the capsule wall thickness to the absorption / radiation capsule diameter is 2 to 10%, water curing at a temperature equal to or higher than the melting point of the phase change material (90 ° C. in the case of threitol) By adding the molten phase change material to the state where the temperature of the solvent containing the urethane monomer or urethane prepolymer is maintained and stirred, at the interface of the phase change material at the same time as the dispersion of the phase change material Microcapsule walls are formed by reacting water or polyhydric alcohols that promote the urethanization reaction with urethane monomers or urethane prepolymers.

  The concentration of the urethane monomer or urethane prepolymer in the first-stage microencapsulation is not particularly limited as long as the urethane monomer or urethane prepolymer is dissolved in the solvent, but is selected between 3 to 30% by mass. Is done. When the concentration of the urethane monomer or urethane prepolymer is low, the formation of the encapsulation wall is not sufficient, and when the concentration is high, the entire solvent containing the urethane monomer or urethane prepolymer is gelled. In order to carry out the microencapsulation reaction in a relatively short time while preventing coalescence of the absorption / radiation capsule diameter, the concentration of the urethane monomer or urethane prepolymer in the solvent is particularly preferably 10 to 20% by mass.

  Since the curing rate of the urethane monomer or urethane prepolymer used for the first stage microencapsulation is high, the first stage microencapsulation reaction time is preferably 10 to 30 minutes, and preferably 15 to 25 minutes. Further preferred. When the reaction time is shorter than 10 minutes, the formation of the encapsulated wall is not sufficient. When the reaction time is longer than 30 minutes, not only is the time wasted, but also water in which the unreacted urethane monomer or urethane prepolymer is dissolved in the solvent. Alternatively, the reaction is promoted by polyhydric alcohols, and it is not preferable because it reacts at other than the phase change material interface.

  The ratio of the capsule wall thickness to the absorption / radiation capsule diameter in the first-stage microencapsulation is 2% or less, but in the second-stage microencapsulation process, the coalescence of the phase change material particles is prevented. Is a sufficient thickness.

  In the first stage microencapsulation, in order to stabilize the dispersed phase change material particles and prevent coalescence of the particles, the amount is preferably 2 to 50% by mass, more preferably 5 to 20%, based on the phase change material. Contains% by weight surfactant.

  Before moving to the second-stage microencapsulation, the absorption / heat dissipation capsule is filtered to separate the unreacted urethane monomer or urethane prepolymer, and the newly prepared solvent containing the urethane monomer or urethane prepolymer is added to the first stage. It is preferable to re-disperse the absorbing / dissipating capsule prepared and filtered in the same manner as in the above microencapsulation.

  The concentration of the second-stage microencapsulated urethane monomer or urethane prepolymer in the solvent is not particularly limited as long as the urethane monomer or urethane prepolymer is dissolved in the solvent, preferably 3 to 15% by mass, Preferably, it is selected between 5 and 12% by mass.

  The second stage microencapsulation reaction time of the urethane monomer or urethane prepolymer used for the second stage microencapsulation is preferably 30 to 90 minutes, and more preferably 35 to 45 minutes. When the reaction time is shorter than 30 minutes, the formation of the encapsulated wall is not sufficient, and when it is longer than 90 minutes, not only is the time wasted, but also water in which the unreacted urethane monomer or urethane prepolymer is dissolved in the solvent. Alternatively, the reaction is promoted by polyhydric alcohols, and it is not preferable because it reacts at other than the phase change material interface.

  By performing the second-stage microencapsulation, the ratio of the capsule wall thickness to the absorption / radiation capsule diameter increases from 2% to 10%, preferably from 5% to 10%, and the phase transition in the microencapsulation wall It will be able to withstand the expansion and contraction of the phase change material accompanying the absorption and release of the material.

  The second-stage microencapsulation may contain 2 to 50% by mass, preferably 5 to 20% by mass of a surfactant with respect to the phase change material in order to prevent coalescence of particles.

  After completion of the second-stage microencapsulation, the absorbing / dissipating capsule is filtered to separate the unreacted urethane monomer or urethane prepolymer.

  When the absorption / radiation capsule is dispersed in the dispersion medium, the absorption / radiation capsule volume fraction with respect to the absorption / radiation capsule dispersion is preferably 10% by volume to 50% by volume, and more preferably 15% by volume to 30% by volume. More preferably. When the amount is less than 10% by volume, the content of the phase change material, which is an effective material for absorbing and releasing heat, is small, and the effect as a heat storage medium is small, which is not preferable. If it exceeds 50% by volume, the viscosity of the capsule for absorbing and releasing heat is remarkably increased, which is not preferable.

  In the case where the absorption / radiation capsule is dispersed in a fluorine-based solvent, the phase change material is preferably contained in an amount of 10 to 40% by mass, more preferably 15 to 30% by mass with respect to the absorption / radiation capsule dispersion. When the amount is less than 10% by mass, the content of the phase change material, which is an effective material for absorbing and releasing heat, is small, and the effect as a heat storage medium is small, which is not preferable. If it exceeds 40% by mass, the viscosity of the capsule for absorbing and releasing heat is remarkably increased, which is not preferable.

  In the case where the absorption / radiation capsule is dispersed in a fluorinated solvent, in order to stabilize the absorption / radiation capsule, the fluorine-based surfactant is preferably 2 to 30% by mass, more preferably 5 to 5%, based on the phase transition material. 20% by mass is contained. If the amount of the fluorosurfactant added is less than 2% by mass, the stability of the dispersion is not sufficient, and if it exceeds 30% by mass, the viscosity of the dispersion increases, which is not preferable.

  A glycol-type flow promoter may be contained in the dispersion of the fluorine-based solvent in the absorption / heat dissipation capsule. The amount of the glycol-based glidant added is preferably 10 to 100% by mass, more preferably 20 to 80% by mass, based on the phase change material. When the amount of the glycol type glidant added is less than 10% by mass, the improvement of the fluidity is not sufficient. When the amount exceeds 100% by mass, the ratio of the phase change material in the dispersion is lowered, which is not preferable.

  According to the above, the microencapsulation wall is less damaged against the expansion / contraction of the phase change material accompanying the absorption / dissipation of the absorption / radiation capsule, and the absorption / absorption with high dispersion stability in the highly safe fluorinated solvent. A heat dissipating capsule, a heat dissipating / heat dissipating capsule dispersion, and a method for producing the same can be provided.

1.1 Production of absorption / radiation capsule and absorption / radiation capsule dispersion by a step-encapsulation reaction (Example 1)
Toluene dehydrated with Molecular Sieve 3A (manufactured by Nacalai Tesque), Takenate M-408 (manufactured by Mitsui Takeda Chemical Co., Ltd.) and a fluoropolymer Lumiflon LF-710F (manufactured by Asahi Glass Co., Ltd.), 90 ml, was heated to 90 ° C. while rotating at 16000 rpm with a homogenizer to prepare a microencapsulant solution container. . Here, the resin ratio of Takenate M-408 and Lumiflon LF-710F was 50/50 mass%. Furthermore, the toluene solution prepared so that it might become 50 mass% of fluorine-type surfactant KB-L110 (made by Neos Co., Ltd.) was prepared, and 6 ml was added to the resin toluene solution. Meanwhile, 10 ml of ion-exchanged water added to Threitol (manufactured by API Corporation) to 10% by mass is heated to 90 ° C. to prepare a threitol melt, which is stirred at 16000 rpm at 90 ° C. The threitol melt was poured into a toluene solution in which Takenate M-408, Lumiflon LF-710F, and KB-L110 were maintained under stirring in about 3 minutes. After pouring the thritol melt, the toluene solution in which Takenate M-408, Lumiflon LF-710F, and KB-L110 are dissolved is kept stirred at 90 ° C. for 30 minutes to complete the microencapsulation reaction. It was. Thereafter, the microencapsulated dispersion was cooled to room temperature, 40 ml of perfluorocarbon (trade name “Fluorinert FC 3283”, manufactured by Sumitomo 3M Limited) was added, and the mixture was uniformly stirred with a magnetic stirrer for 2 minutes. After completion of the stirring, the mixture was allowed to stand at room temperature for 30 minutes to obtain 63 g of a water-soluble phase transition material dispersion in which the upper layer was toluene and the lower layer was microencapsulated. In 63 g of the fluorinated solvent dispersion of the microencapsulated water-soluble phase change material particles, 39.6 g of perfluorocarbon, 13 g of threitol, 6.5 g of microcapsules, and 3.9 g of fluorinated surfactant (KB-L110) were added. Contains. Microencapsulated water-soluble phase change material particles dispersed in a fluorinated solvent are measured with a laser diffraction / scattering particle size distribution analyzer LA-910 (manufactured by Horiba, Ltd.), and the volume average diameter is 5 μm. It was confirmed. The amount of threitol contained in the heat-absorbing / heat-releasing capsule particles is the literature value of slatol, which is obtained by measuring the change in latent heat of fusion obtained by repeating heating and cooling 10 times in the same sample using a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.). It was calculated by comparing with. The absorption / heat dissipation capsule particles contained 84% by mass of thritol, and the thritol content was 82% by mass even after repeated heating and cooling 10 times. Moreover, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the heat-absorbing / radiating capsule was measured to be 70 ° C to 75 ° C. The microcapsulated particle dispersion separated from the upper / lower layer after leaving this absorbing / dissipating capsule dispersion at room temperature for 24 hours was separated, and the mass of the lower fluorine solvent (perfluorocarbon) was measured to be 10 g. That is, 16% by mass of the dispersion mass was separated.

(Example 2)
A fluorine-based solvent dispersion 63 g was obtained by the method of Example 1 except that the resin ratio of Takenate M-408 and Lumiflon LF-710F was 40/60% by mass. The microencapsulated water-soluble phase change material particles dispersed in a fluorine-based solvent were measured with a laser diffraction / scattering particle size distribution analyzer LA-910 (manufactured by Horiba, Ltd.), and the volume average diameter was 5.5 μm. I confirmed that there was. The amount of threitol contained in the heat-absorbing / heat-releasing capsule particles is the literature value of slatol, which is obtained by measuring the change in latent heat of fusion obtained by repeating heating and cooling 10 times in the same sample using a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.). It was calculated by comparing with. The absorption / heat dissipation capsule particles contained 80% by mass of thritol, and the slatitol content of 79% by mass was exhibited even after repeated heating and cooling 10 times. Moreover, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the absorption / radiation capsule was measured to be 70 ° C to 75 ° C. When the microencapsulated particle dispersion separated from the upper / lower layer after leaving this absorbing / dissipating capsule dispersion at room temperature for 24 hours was separated, and the mass of the lower fluorine solvent (perfluorocarbon) was measured, it was 7 g. That is, 11% by mass of the dispersion mass was separated.

(Example 3)
A fluorine-based solvent dispersion 63 g was obtained by the method of Example 1 except that the resin ratio of Takenate M-408 and Lumiflon LF-710F was 60/40% by mass. Microencapsulated water-soluble phase change material particles dispersed in a fluorinated solvent are measured with a laser diffraction / scattering particle size distribution analyzer LA-910 (manufactured by Horiba, Ltd.), and the volume average diameter is 5 μm. It was confirmed. The amount of threitol contained in the heat-absorbing / heat-releasing capsule particles is the literature value of slatol, which is obtained by measuring the change in latent heat of fusion obtained by repeating heating and cooling 10 times in the same sample using a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.). It was calculated by comparing with. The absorbing / dissipating capsule particles contained 85% by weight of threitol, and the content of threitol was 83% by weight even after repeated heating and cooling 10 times. Moreover, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the absorption / radiation capsule was measured to be 70 ° C to 75 ° C. The microcapsulated particle dispersion separated from the absorbent / heat-radiating capsule dispersion at room temperature for 24 hours and then separated into the upper layer was separated, and the mass of the lower layer fluorinated solvent (perfluorocarbon) was measured to be 16 g. That is, 25% by mass of the mass of the dispersion is separated.

Example 4
A fluorine-based solvent dispersion 63 g was obtained by the method of Example 1 except that the resin ratio of Takenate M-408 and Lumiflon LF-710F was 20/80 mass%. Microencapsulated water-soluble phase change material particles dispersed in a fluorinated solvent are measured with a laser diffraction / scattering particle size distribution analyzer LA-910 (manufactured by Horiba, Ltd.), and the volume average diameter is 5 μm. It was confirmed. The amount of threitol contained in the heat-absorbing / heat-releasing capsule particles is the literature value of slatol, which is obtained by measuring the change in latent heat of fusion obtained by repeating heating and cooling 10 times in the same sample using a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.). It was calculated by comparing with. The absorbent / heat-radiating capsule particles contained 60% by mass of thritol, and showed a slateol content of 50% by mass even after repeated heating and cooling 10 times. Moreover, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the absorption / radiation capsule was measured to be 70 ° C to 75 ° C. The microcapsulated particle dispersion separated from the absorbent / heat-radiating capsule dispersion was allowed to stand at room temperature for 24 hours and then separated into the upper layer, and the mass of the lower layer fluorine-based solvent (perfluorocarbon) was measured to be 5 g. That is, 8% by mass of the dispersion mass was separated.

(Example 5)
A fluorine-based solvent dispersion 63 g was obtained by the method of Example 1 except that the resin ratio of Takenate M-408 and Lumiflon LF-710F was 80/20% by mass. Microencapsulated water-soluble phase change material particles dispersed in a fluorinated solvent are measured with a laser diffraction / scattering particle size distribution analyzer LA-910 (manufactured by Horiba, Ltd.), and the volume average diameter is 5 μm. It was confirmed. The amount of threitol contained in the heat-absorbing / heat-releasing capsule particles is the literature value of slatol, which is obtained by measuring the change in latent heat of fusion obtained by repeating heating and cooling 10 times in the same sample using a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.). It was calculated by comparing with. The absorption / heat dissipation capsule particles contained 82% by mass of threitol, and showed a 77% by mass thritol content even after repeated heating and cooling 10 times. Moreover, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the absorption / radiation capsule was measured to be 70 ° C to 75 ° C. The microcapsulated particle dispersion separated from the upper / lower layer after leaving this absorbing / dissipating capsule dispersion at room temperature for 24 hours was separated, and the mass of the lower fluorine solvent (perfluorocarbon) was measured to be 25 g. That is, 40% by mass of the dispersion liquid was separated.

(Example 6)
As a phase transition material, 10 g of slateol (manufactured by API Corporation) was used. In the first stage microencapsulation reaction, 60 g% of microencapsulating agent 6 g (Takenate M-408 (produced by Mitsui Takeda Chemical Co., Ltd.), which is a tolylene diisocyanate-based prepolymer) A certain Lumiflon LF-710F (Asahi Glass Co., Ltd. 3 g), 5% by mass of fluorosurfactant KB-L110 (Neos Co., Ltd.) 0.5 g with respect to Threitol, and the concentration of the microencapsulating agent is 16% by mass. 38 g of toluene solution dissolved in 31.5 g of toluene dehydrated with Molecular Sieve 3A (manufactured by Nacalai Tesque Co., Ltd., reagent grade) is heated to 90 ° C. while rotating at 16000 rpm with a homogenizer. did. On the other hand, 11 g of 1 g (10% by mass) of ion-exchanged water added to 10 g of threitol was heated to 90 ° C. to prepare a threitol melt and maintained at 90 ° C. with stirring at 16000 rpm with stirring. It was added to 38 g of toluene solution. The toluene solution was kept stirring at 90 ° C. for 20 minutes to complete the first microencapsulation reaction. After completion of the reaction, the reaction solution was rapidly cooled to room temperature, and the toluene solution containing the unreacted microencapsulating agent was separated from the absorption / release heat capsule by decantation.

  The dried capsule for absorbing and releasing heat was observed with an optical microscope and confirmed to be spherical particles having a particle diameter of about 20 μm. The amount of thritol of the phase transition material contained in the absorption / radiation capsule particles was measured by a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.) for the latent heat of fusion and the melting temperature. The capsule contains 97% by weight of thritol based on the latent heat of fusion of the capsule, and the capsule wall thickness is calculated to be 0.15 μm. For the capsule diameter of 20 μm (radius 10 μm), 1.5% It became the thickness ratio of the capsule wall body. After repeating the two absorption / heat dissipation cycles, it was surmised that some of the absorption / radiation capsules were united and the capsule wall could not be formed sufficiently. Further, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the absorption / radiation capsule was measured to be 87 ° C.

(Comparative Example 1)
An attempt was made to obtain 63 g of the fluorinated solvent dispersion by the method of Example 1 except that the resin ratio of Takenate M-408 and Lumiflon LF-710F was 0/100% by mass. The microencapsulated water-soluble phase change material particles could not be obtained, and a mass in which the microencapsulating agent and the water-soluble phase change material were combined was obtained.

(Comparative Example 2)
A fluorine-based solvent dispersion 63 g was obtained by the method of Example 1 except that the resin ratio of Takenate M-408 and Lumiflon LF-710F was 100/0% by mass. Microencapsulated water-soluble phase change material particles dispersed in a fluorine-based solvent are measured with a laser diffraction / scattering particle size distribution analyzer LA-910 (manufactured by Horiba, Ltd.), and the volume average diameter is 4 μm. It was confirmed. The amount of threitol contained in the heat-absorbing / heat-releasing capsule particles is the literature value of slatol, which is obtained by measuring the change in latent heat of fusion obtained by repeating heating and cooling 10 times in the same sample using a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.). It was calculated by comparing with. The absorption / heat dissipation capsule particles contained 80% by mass of thritol, and the thritol content was 75% by mass even after repeated heating and cooling 10 times. Moreover, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the absorption / radiation capsule was measured to be 70 ° C to 75 ° C. When the microencapsulated particle dispersion separated from the upper / lower layer after leaving this absorbing / dissipating capsule dispersion at room temperature for 24 hours was separated, the mass of the lower fluorine solvent (perfluorocarbon) was measured and found to be 32 g. That is, 51% by mass of the dispersion liquid was separated.

  The results of these Examples 1 to 5 and Comparative Examples 1 and 2 are summarized in Table 1. In the absorption / heat dissipation capsule containing a water-soluble phase change substance inside, as a capsule wall, a water-curable urethane monomer or When a urethane prepolymer and a fluorine-based polymer having a hydroxyl group in the molecule are contained, the water-soluble phase transition in the absorbing / dissipating capsule against the expansion / contraction of the phase change material accompanying the absorbing / dissipating of the absorbing / dissipating capsule The amount of the fluorinated solvent was reduced in a highly safe fluorinated solvent with little decrease in the amount of substances.

2.2 Production of absorption / radiation capsules and absorption / radiation capsule dispersions by encapsulating reaction
Manufacture of absorption / radiation capsules (Example 7)
<First stage microencapsulation reaction>
For the preparation of the one-time absorption / radiation capsule, 10 g of slateol (manufactured by API Corporation) was used as a phase change material. In the first stage microencapsulation reaction, 60 g% of microencapsulating agent 6 g (Takenate M-408 (produced by Mitsui Takeda Chemical Co., Ltd.), which is a tolylene diisocyanate-based prepolymer) A certain Lumiflon LF-710F (Asahi Glass Co., Ltd. 3 g), 5% by mass of fluorosurfactant KB-L110 (Neos Co., Ltd.) 0.5 g with respect to Threitol, and the concentration of the microencapsulating agent is 16% by mass. 38 g of toluene solution dissolved in 31.5 g of toluene dehydrated with Molecular Sieve 3A (manufactured by Nacalai Tesque Co., Ltd., reagent grade) is heated to 90 ° C. while rotating at 16000 rpm with a homogenizer. did. On the other hand, 11 g of 1 g (10% by mass) of ion-exchanged water added to 10 g of threitol was heated to 90 ° C. to prepare a threitol melt and maintained at 90 ° C. with stirring at 16000 rpm with stirring. It was added to 38 g of toluene solution. The toluene solution was kept stirring at 90 ° C. for 20 minutes to complete the first microencapsulation reaction. After completion of the reaction, the reaction solution was rapidly cooled to room temperature, and the toluene solution containing the unreacted microencapsulating agent was separated from the absorption / release heat capsule by decantation.

<Second stage microencapsulation reaction>
In the second microencapsulation reaction, 6 g of microencapsulating agent 6 g (1,3-bis (isocyanatomethyl) cyclohexane prepolymer 3 g of Takenate M-605N with respect to threitol, Lumiflon LF- 710F (3 g) and 5% by mass of fluorosurfactant (KB-L110) with respect to threitol (0.5 g) were dissolved in 54 g of toluene dehydrated with molecular sieve 3A so that the concentration of the microencapsulating agent was 10% by mass. 60.5 g of toluene solution was heated to 90 ° C. while rotating at 16000 rpm with a homogenizer. On the other hand, the absorption / release heat capsule obtained by the first-stage microencapsulation was added to 60.5 g of the toluene solution maintained at 90 ° C. with stirring at 16000 rpm. The toluene solution was kept stirring at 90 ° C. for 40 minutes to complete the second-stage microencapsulation reaction. After completion of the reaction, the reaction solution was rapidly cooled to room temperature, and the toluene solution containing the unreacted microencapsulating agent was separated from the absorption / release heat capsule by decantation. The separated absorption / radiation capsule was washed with 50 g of toluene dehydrated with molecular sieve 3A to completely remove the unreacted microencapsulating agent, and the solvent was removed from toluene at room temperature under reduced pressure. Obtained.

  The dried absorption / radiation capsule was observed with an optical microscope and confirmed to be spherical particles having a particle diameter of about 20 μm as shown in FIG. The amount of thritol of the phase transition material contained in the absorption / radiation capsule particles was measured by a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.) for the latent heat of fusion and the melting temperature. 82 mass% of thritol is contained in the capsule from the latent heat of fusion of the absorption / radiation capsule, and the capsule wall thickness is 0.92 μm, that is, 9.2% of the absorption / radiation capsule diameter of 20 μm (radius 10 μm). It became the thickness ratio of the capsule wall. After repeating the two absorption / radiation cycles, the absorption / radiation capsule maintained a spherical shape. Further, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the heat-absorbing / radiating capsule was measured to be 88 ° C.

(Example 8)
In the first-stage microencapsulation reaction, 6 g of a microencapsulating agent of 60% by mass with respect to threitol (3 g of Takenate M-408, 3 g of Lumiflon LF-710F) and 5% by mass of a fluorosurfactant with respect to threitol ( The same operation as in Example 7 was performed except that 0.5 g of KB-L110) was dissolved in 114 g of toluene dehydrated with molecular sieve 3A so that the concentration of the microencapsulating agent was 5% by mass.

  The dried capsule for absorbing and releasing heat was observed with an optical microscope and confirmed to be spherical particles having a particle diameter of about 20 μm. The amount of thritol of the phase transition material contained in the absorption / radiation capsule particles was measured by a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.) for the latent heat of fusion and the melting temperature. From the amount of latent heat of fusion of the absorbing / dissipating capsule, 94% by mass of thritol is contained in the capsule, and the capsule wall thickness is 0.27 μm, that is, 2.7% of the absorbing / dissipating capsule diameter of 20 μm (radius 10 μm). It became the thickness ratio of the capsule wall. After repeating the two absorption / radiation cycles, the absorption / radiation capsule maintained a spherical shape. Further, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the heat-absorbing / radiating capsule was measured to be 88 ° C.

Example 9
In the second-stage microencapsulation reaction, 6 g of a microencapsulating agent of 60% by mass with respect to threitol (3 g of Takenate M-605N and 3 g of Lumiflon LF-710F) and 5% by mass of a fluorosurfactant with respect to threitol ( The same operation as in Example 7 was performed except that 0.5 g of KB-L110) was dissolved in 114 g of toluene dehydrated with molecular sieve 3A so that the concentration of the microencapsulating agent was 5% by mass.

  The dried capsule for absorbing and releasing heat was observed with an optical microscope and confirmed to be spherical particles having a particle diameter of about 20 μm. The amount of thritol of the phase transition material contained in the absorption / radiation capsule particles was measured by a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.) for the latent heat of fusion and the melting temperature. From the amount of latent heat of fusion of the absorbing / dissipating capsule, 84% by mass of thritol is contained in the capsule, and the capsule wall thickness is 0.81 μm, that is, 8.1% with respect to the absorbing / dissipating capsule diameter of 20 μm (radius 10 μm). It became the thickness ratio of the capsule wall. After repeating the two absorption / radiation cycles, the absorption / radiation capsule maintained a spherical shape. Further, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the absorption / radiation capsule was measured to be 87 ° C.

(Example 10)
In the second-stage microencapsulation reaction, the same operation as in Example 7 was performed, except that 0.5 g of 5% by mass of a fluorosurfactant (KB-L110) was not added to threitol.

  The dried capsule for absorbing and releasing heat was observed with an optical microscope and confirmed to be spherical particles having a particle diameter of about 20 μm. The amount of thritol of the phase transition material contained in the absorption / radiation capsule particles was measured by a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.) for the latent heat of fusion and the melting temperature. Based on the amount of latent heat of fusion of the absorbing / dissipating capsule, 88% by mass of thritol is contained in the capsule, and the capsule wall thickness is 0.58 μm, that is, 5.8% of the absorbing / dissipating capsule diameter of 20 μm (radius 10 μm). It became the thickness ratio of the capsule wall. After repeating the two absorption / radiation cycles, the absorption / radiation capsule maintained a spherical shape. Further, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the absorption / radiation capsule was measured to be 87 ° C.

(Example 11)
As an accelerator for the encapsulation reaction in 10 g of thritol, 1 g (10 mass%) of diethylene glycol (DEG) is used instead of 1 g (10 mass%) of ion-exchanged water, and the first stage microencapsulation reaction time is 120 minutes. The same operation as in Example 7 was performed except that the microencapsulation reaction time was changed to 120 minutes.

  The dried capsule for absorbing and releasing heat was observed with an optical microscope and confirmed to be spherical particles having a particle diameter of about 20 μm. The amount of thritol of the phase transition material contained in the absorption / radiation capsule particles was measured by a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.) for the latent heat of fusion and the melting temperature. From the amount of latent heat of fusion of the absorbing / dissipating capsule, 84% by mass of thritol is contained in the capsule, and the capsule wall thickness is 0.80 μm, that is, 8.0% against the absorbing / dissipating capsule diameter of 20 μm (radius 10 μm). It became the thickness ratio of the capsule wall. After repeating the two absorption / radiation cycles, the absorption / radiation capsule maintained a spherical shape. Further, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the heat-absorbing / heat-radiating capsule was measured to be 72 ° C.

(Comparative Example 3)
The first stage microencapsulation reaction does not contain Lumiflon LF-710F, which is a fluoropolymer, as a microencapsulating agent, but only 6 g of Takenate M-408, a tolylene diisocyanate prepolymer, and second stage microencapsulation. Example except that Lumiflon LF-710F, which is a fluorine-based polymer, is not included as a microencapsulating agent in the reaction, and 6 g is formed using only Takenate M605N, which is a 1,3-bis (isocyanatomethyl) cyclohexane-based prepolymer. The same operation as 7 was performed.

  When the separated absorption / radiation capsule was washed with 50 g of toluene dehydrated with molecular sieve 3A, the absorption / radiation capsule aggregated into a large lump, and an absorption / radiation capsule having a particle diameter of 10 to 50 μm was not formed.

(Comparative Example 4)
In the first-stage microencapsulation reaction, the same operation as in Example 7 was performed except that 0.5 g of 5% by mass of a fluorosurfactant (KB-L110) was not added to the threitol.

  The dried capsule for absorbing and releasing heat was observed with an optical microscope and confirmed to be spherical particles having a particle diameter of about 20 μm. The amount of thritol of the phase transition material contained in the absorption / radiation capsule particles was measured by a differential thermal analyzer DSC3100 (manufactured by Mac Science Co., Ltd.) for the latent heat of fusion and the melting temperature. The capsule contains 100% by weight of thritol from the latent heat of fusion of the absorbing / dissipating capsule, and the capsule wall thickness is calculated to be 0 μm. Thickness ratio. It was surmised that after the two absorption / heat dissipation cycles were repeated, the absorption / radiation capsules were united into a large lump and a capsule wall could not be formed sufficiently. Further, from the measurement result of the differential thermal analyzer DSC3100, the melting temperature of thritol in the absorption / radiation capsule was measured to be 87 ° C.

(Comparative Example 5)
In the first-stage microencapsulation reaction, 1,3-bis (isocyanatomethyl) having a slow curing time is used instead of Takenate M-408, which is a tolylene diisocyanate prepolymer having a fast curing time, which is a microencapsulating agent. The same operation as in Example 7 was performed except that Takenate M-605N, which is a cyclohexane-based prepolymer, was used to extend the first-stage microencapsulation reaction time from 20 minutes to 60 minutes.

  Gelation was observed in the entire reaction solution at the end of the second-stage microencapsulation reaction, and an absorption / radiation capsule could not be obtained.

  Regarding Examples 7 to 11 above, seeds of phase change material (PCM), seeds of accelerator for encapsulating reaction, amount added, seeds of encapsulating agent and fluoropolymer in first and second stage microencapsulation reactions Ratio, reaction temperature, reaction time, amount of encapsulating agent added, concentration of encapsulating agent in toluene solution, amount of surfactant added, diameter of absorbing / dissipating capsule, capsule wall thickness, capsule wall ratio, phase change material (PCM) ), The melting temperature of the phase change material (PCM), and the maintenance of the capsule wall after two absorption / release cycles are shown in Table 2. Similarly, it shows in Table 3 about Example 6 and 7 and Comparative Examples 3-5.

Production of absorption / radiation capsule dispersion (Example 12)
Perfluorocarbon (Fluorinert FC 3283, manufactured by Sumitomo 3M Co.) 56 g (5.6 times the phase change material) perfluorocarbon (Fluoronate FC 3283) to 11.9 g (10 g of phase change material) of the absorption / heat dissipation capsule prepared in Example 7, fluorine-based surface activity Agent KB-L110 (manufactured by Neos Co., Ltd.) 1.25 g (12.5% by mass with respect to the phase change material), diethylene glycol monobutyl ether acetate (DEG-MBuEA) 5 g (with respect to the phase change material) 50 mass%) was added and stirred at room temperature to prepare 75.15 g of an absorbing / dissipating capsule dispersion. The content of the phase change material contained in the absorption / radiation capsule dispersion is 13.3% by mass. Since the density of perfluorocarbon (Fluorinert FC 3283) as a dispersion medium is 1.82 g / cm ³ , the volume fraction of the phase change material contained in the absorbing / dissipating capsule dispersion is approximately 20% by volume.

  The thus-prepared absorption / radiation capsule dispersion was heated at 90 ° C. for 30 minutes under non-stirring conditions, and then allowed to cool to room temperature and repeatedly cooled for 10 times. Since the difference was large, the two phases were separated in the stationary state, but when the stirring was added, the original dispersed state was restored. When the latent heat of fusion and the melting temperature were measured with a differential thermal analyzer DSC3100 after the absorption / radiation cycle was carried out 10 times, 83 mass% of thritol was found in the capsule based on the latent heat of fusion of the absorption / radiation capsule. Contained, the melting temperature of threitol was measured to be 88 ° C., and the value before the absorption / release heat cycle was substantially maintained.

(Example 13)
The same as Example 12 except that the fluorosurfactant KB-L110 was changed to 0.5 g (5% by mass with respect to the phase change material) with respect to 11.9 g of the absorption / heat dissipation capsule (10 g for the phase change material). The absorption / radiation capsule dispersion was prepared by the same method, and the same absorption / radiation cycle was carried out.

  After 10 absorption / release cycles, the two-phase separation occurred in the standing state, but when the stirring was applied, the original dispersion state was restored. Moreover, 83 mass% of thritol was contained in the capsule from the amount of latent heat of fusion of the absorption / radiation capsule, and the melting temperature of thritol was measured to be 87 ° C., and the value before the absorption / radiation cycle was almost maintained. .

(Comparative Example 6)
An absorbent / heat dissipating capsule dispersion was prepared in the same manner as in Example 12, except that the fluorosurfactant KB-L110 was not added to 11.9 g of the absorbing / dissipating capsule (10 g of the phase change material). The same absorption / release heat cycle was carried out.

  After carrying out the absorption / heat radiation cycle 10 times, the two phases were separated in a stationary state, and even if agitation was added, the original dispersed state was not restored.

(Comparative Example 7)
Except for the fluorine-based surfactant KB-L110, 5 g (50% by mass with respect to the phase change material) with respect to 11.9 g of the absorption / heat dissipation capsule (10 g with the phase change material), the same method as in Example 12 An absorption / radiation capsule dispersion was prepared, but a dispersion with very high viscosity and no fluidity was obtained.

(Comparative Example 8)
As a glycol-based glidant, diethylene glycol monobutyl ether acetate (DEG-MBuEA) was absorbed in the same manner as in Example 12 except that it was not added to 11.9 g of the heat-absorbing and heat-dissipating capsule (10 g of the phase change material). -A heat dissipation capsule dispersion was prepared, but a dispersion with very high viscosity and no fluidity was obtained.

  About Example 12, 13 and Comparative Examples 6-8, content (mass%) of the phase change material (PCM) with respect to an absorption-heat dissipation capsule seed | species and a dispersion liquid, surfactant seed | species and addition amount, glidant seed | species addition, and addition Table 4 shows the amount of the phase change substance in the absorption / radiation capsule before and after the cycle.

  Applications of the absorbing / radiating capsule and absorbing / dissipating capsule dispersion of the present invention include applications such as a cooling fluid medium for an automobile engine and a fuel cell, and a heat transfer medium for a heat storage system. Since the apparent specific heat per unit volume is larger than that of a conventional heat transfer medium, the circulation flow rate of the medium can be reduced, contributing to energy saving.

Claims (9)

  An absorbent comprising a membrane-like capsule wall that forms a sealed space inside, and a phase change material that dissolves in water or a water-miscible organic solvent as a sealed material sealed in the sealed space of the capsule wall. A heat-radiating capsule that is a heat-dissipating capsule and contains a phase change material composed of at least one of sugar alcohol, urea, and thiourea as the encapsulating material, and a water-curable urethane as the capsule wall. An air-absorbing / dissipating capsule comprising a monomer or urethane prepolymer and a fluorine-based polymer having a hydroxyl group in the molecule.   The mass ratio of the water-curable urethane monomer or urethane prepolymer of the capsule wall body to the fluorine-based polymer having a hydroxyl group in the molecule is 40/60 to 60/40. Absorption / heat dissipation capsule.   The capsule according to claim 1 or 2, wherein the encapsulating substance contains water or a polyhydric alcohol.   The absorption / heat dissipation capsule according to claim 3, wherein the polyhydric alcohol is composed of at least one of ethylene glycol, diethylene glycol, and glycerin.   The particle diameter of the absorbing / dissipating capsule is 10 to 50 μm, and the ratio of the thickness of the capsule wall body to the particle diameter of the absorbing / dissipating capsule is 2 to 10%. The absorption / radiation capsule according to any one of the above items.   An absorbing / dissipating capsule dispersion comprising the fluorine-based dispersion medium and the absorbing / dissipating capsule according to any one of claims 1 to 5 dispersed in the dispersing medium.   The absorption / heat dissipation capsule dispersion according to claim 6, wherein the phase change material is 10 to 40% by mass with respect to the dispersion, and the fluorosurfactant is 2 to 30% by mass with respect to the phase change material. The above-mentioned absorbing / dissipating capsule dispersion, wherein the glycol-based glidant is contained in an amount of 10 to 100% by mass with respect to the phase change material.   It is a manufacturing method of the absorption-heat radiation capsule of any one of Claims 1-5, Comprising: In the coexistence of surfactant by the urethane monomer or urethane prepolymer with a quick hardening rate as 1st step | paragraph microencapsulation. The method as described above, wherein after the formation of the encapsulated wall, a further encapsulated wall is formed by urethane monomer or urethane prepolymer as the second stage microencapsulation.   When the encapsulation wall is formed with a urethane monomer or urethane prepolymer having a high curing speed as the first-stage microencapsulation, 2 to 50% by mass of a surfactant is contained with respect to the phase change material. The manufacturing method of the absorption-heat radiation capsule of Claim 8.

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