JP2006335940A - Process for manufacturing emulsion-type heat storage material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the stability of an emulsion-type heat storage material to temperature changes. <P>SOLUTION: The process for manufacturing the emulsion-type heat storage material comprises dispersing a phase change material into water using an emulsifier. The emulsifier is a nonionic and an amphoteric surfactant. The phase change material is added in an amount of 10-70 wt.% of the total emulsion including water. The total amount of the emulsifier added to 100 pts.wt. of the phase change material is 0.5-200 pts.wt. Preferably, the nonionic surfactant is a polyoxyalkylene addition product of an aliphatic alcohol and the amphoteric surfactant is an amino acid-type. The adequate mixing ratio of the nonionic surfactant to the amphoteric surfactant is nonionic/amphoteric=1/9-1/1. Addition of the surfactants at the adequate mixing ratio promotes the contribution to the stability of the emulsion to temperature changes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a method for producing an emulsion heat storage material that can satisfactorily stabilize emulsion particles even when cooling and heating are repeated.

As a heat storage material for utilizing latent heat generated in accordance with a phase change of a substance, organic compounds represented by ice and aliphatic hydrocarbons, inorganic salts, and the like are known. Emulsion type, capsule type, fixed type, etc. are being studied as heat storage materials using aliphatic hydrocarbons, but fluid type emulsion type and capsule type are excellent considering thermal efficiency and ease of control. ing.
The emulsion type is advantageous in terms of cost because it is easier to prepare than the capsule type, and is expected to become the mainstream in the future from the point of mass supply. On the other hand, the stability in repeated cooling and heating is capsule type. There is a problem that it is inferior.
That is, in a general emulsion, the particles and the emulsifier constituting the emulsion are stabilized by attracting each other by the action of intermolecular force. When such an emulsion is used in a heat storage and heat transfer system, cooling and heating are repeated. As a result, the inside of the particle changes from a solid to a liquid or vice versa, so that the volume of the particle itself changes greatly each time. For this reason, the emulsifier at the interface is easily detached due to its unstable state, and the required long-term emulsion stability is not sufficiently satisfactory.

The following are mentioned as a prior art of an emulsion type heat storage material.
First, Patent Document 1 uses a nonionic surfactant and an anionic surfactant in water (dispersion medium) for n-paraffin (dispersoid) in order to prevent phase separation for a long period of time. A latent heat storage material that has been emulsified is disclosed (see claim 1, paragraph 9).

  In Patent Document 2, for the purpose of facilitating coagulation and improving heat storage efficiency (see paragraph 6), an oily substance (phase change substance) is mixed with a low HLB surfactant and a high HLB surfactant in water. A heat storage material dispersed in is disclosed. The surfactant can be mixed and used under the condition that the total HLB does not deviate from a specific range (see paragraph 16). For example, in Example 1, two nonionic surfactants and one anionic surfactant are used. Is used as an emulsifier (see paragraph 31).

Patent Document 3 discloses an emulsion-type heat storage material that improves the dispersibility of an oily substance and improves the fluidity by limiting the viscosity of an emulsifier that disperses the oily substance (phase change substance) in water to a specific range. (See claim 1, paragraph 6, paragraph 46).
As the emulsifier, a nonionic surfactant may be used alone (the examples are examples of this single use), but nonionic and anionic surfactants, nonionic and cationic surfactants, nonionic and amphoteric It describes that a surfactant may be used in combination (see paragraph 22).

Patent Document 4 discloses a coolant in which a regenerator in which a hydrophobic aliphatic compound having a melting point in a specific range is dispersed as dispersed particles in an aqueous medium is enclosed in a bag (see claim 1).
An emulsion of dispersed particles may be formed with an emulsifier composed of an anionic, nonionic or cationic surfactant or a polymeric dispersant (protective colloid, etc.) (see paragraph 24). A combination of anionic and nonionic surfactants) (see paragraph 29).

  On the other hand, Patent Document 5 relates to a microcapsule type heat storage material, which is a heat storage material in which a core material containing paraffin is enclosed in a partition wall made of polyurethane resin or polyurea resin (see claim 1). The oil phase mixture containing the above paraffin is dispersed in water using an emulsifier (see paragraph 26), and the emulsifier may be an anionic, nonionic, amphoteric surfactant, or a protective colloid alone or in combination of two or more. It is described that this may be done (see paragraph 28). In the examples, the protective colloid is used for dispersion.

  Patent Document 6 relates to a water (ice) slurry, not a heat storage material that uses paraffins as phase change substances, and one or two kinds of specific surfactants are prepared when preparing the ice slurry. It is described that the above can be used (see claims 1 to 11 and paragraph 4), and in addition to the specific surfactant, known anionic, cationic and amphoteric surfactants can be used in combination ( Claims 12-27, paragraph 68).

Japanese Patent Laid-Open No. 7-126614 JP 2004-2833 A JP 2004-231838 A JP 2004-189999 A JP 2004-189843 A JP 2001-131538 A

Some prior arts of the above-mentioned emulsion-type heat storage material are aimed at emulsion stability, but actually, the emulsion stability accompanying repeated heating and cooling is not yet satisfactory (refer to the test examples described later).
This invention makes it a technical subject to improve the stability with respect to the temperature change of an emulsion thermal storage material.

As a result of earnestly studying the stability of the emulsion heat storage material by changing the temperature by changing the type and blending ratio of the emulsifier, the present inventors have found that the addition rate of the phase change material to the emulsion system and the addition rate of the emulsifier to the phase change material It was found that the emulsion stability can be improved satisfactorily when two types of specific types of emulsifiers are combined under the condition of adjusting to a specific range.
That is, not the combination of nonionic and anionic surfactants as described in Patent Document 1 above, but the combination of nonionic and amphoteric surfactants contributes well to emulsion stability, particularly aliphatic alcohols. The combination of polyoxyalkylene adducts (nonionic surfactants) and amino acid-type amphoteric surfactants contributes to this contribution, and when nonionic and amphoteric surfactants are mixed, the main component nonionic properties The present invention has been completed by finding out that the effect of contributing to emulsion stability can be better brought out by mixing the surfactant with an amphoteric surfactant as an auxiliary component in an appropriate ratio not too much or too little.

That is, the present invention 1 is a method for producing an emulsion-type heat storage material in which a phase change material is dispersed in water using an emulsifier.
The emulsifier is a nonionic surfactant and an amphoteric surfactant,
The addition ratio of the phase change material to the whole emulsification system containing water is 10 to 70% by weight, and the total addition amount of the emulsifier to 100 parts by weight of the phase change material is 0.5 to 200 parts by weight. It is a manufacturing method of an emulsion type heat storage material.

  The present invention 2 is the emulsion according to the present invention 1, wherein the nonionic surfactant is an aliphatic alcohol, a polyoxyalkylene adduct of fatty acids, or a polyoxyalkylene adduct having an aromatic ring. It is a manufacturing method of a type | mold heat storage material.

  Invention 3 is a method for producing an emulsion-type heat storage material according to Invention 1 or 2, wherein the amphoteric surfactant is at least one of a betaine-type, amino acid-type, and imidazoline-type surfactant. .

  Invention 4 is as described in any one of Inventions 1 to 3, wherein the weight mixing ratio of the nonionic surfactant and the amphoteric surfactant is amphoteric surfactant / nonionic surfactant = 1/9 to 1/1. It is a manufacturing method of the emulsion type heat storage material characterized by the above-mentioned.

  Invention 5 is that in any one of Inventions 1 to 3, wherein the nonionic surfactant is a polyoxyalkylene adduct of aliphatic alcohols, and the amphoteric surfactant is an amino acid type surfactant. It is the manufacturing method of the emulsion type heat storage material characterized by these.

  Invention 6 is a method for producing an emulsion-type heat storage material according to any one of Inventions 1 to 5, wherein a thickener is added during or after the emulsification step.

The present invention 7, in any of the above the present invention 1-6, a phase change material, normal paraffins C ₈ -C _40, isoparaffins, at least one aliphatic hydrocarbon selected from the group consisting of cycloparaffins It is a manufacturing method of an emulsion type heat storage material characterized by being.

  Invention 8 is a method for producing an emulsion-type heat storage material according to any one of Inventions 1 to 7, wherein a supercooling inhibitor is further added in the emulsification step.

  Invention 9 is an emulsion-type heat storage according to Invention 8, wherein the supercooling inhibitor is an aliphatic hydrocarbon having a melting point higher than that of the phase change material and good compatibility with the phase change material. It is a manufacturing method of material.

In the present invention, the phase change material is dispersed in water by using two types of emulsifiers of nonionic and amphoteric surfactants, so that the stability of the emulsion particles against temperature change is improved, and the obtained heat storage material is cooled and heated. Excellent emulsion stability by repetition.
In particular, when a polyoxyalkylene adduct (nonionic surfactant) of an aliphatic alcohol is combined with an amino acid type amphoteric surfactant, contribution to emulsion stability can be enhanced (see Invention 5). In addition, when the main component nonionic surfactant is mixed in an appropriate weight ratio that is not too small and not too small as an auxiliary component amphoteric surfactant, that is, amphoteric / nonionic property = 1/9 to 1/1. Thus, the contribution effect to the emulsion stability can be better extracted (see the present invention 4).

  (2) In the present invention, a high viscosity heat storage material can be produced by adding a thickener to the emulsification system (see the present invention 6). When preparing a high-viscosity heat storage material by adding this thickener (polyacrylic acid emulsion or the like), a quaternary ammonium salt type such as betaine type or imidazolinium betaine type is used as an amphoteric surfactant. However, the addition of a thickener alone does not increase the viscosity and requires the addition of a neutralizing agent. However, if an amino acid type whose molecular end is salified with sodium or the like is used, the viscosity can be increased without neutralization. The productivity of the heat storage material can be simplified and the productivity can be increased.

  The present invention is an emulsion-type heat storage material in which phase change substances are dispersed in water using two types of emulsifiers, nonionic and amphoteric surfactants, and a thickener is added to form a high-viscosity heat storage material. You can also.

Phase change materials used in the present invention include aliphatic hydrocarbons, inorganic hydrates such as calcium chloride and sodium sulfate hydrates, fatty acids such as lauric acid, palmitic acid and stearic acid, esterified products thereof, Any higher alcohols or other substances that undergo phase changes such as a solid phase and a liquid phase can be used without particular limitation.
As the phase change substance, as shown in the present invention 7, C _{8 to} C ₄₀ aliphatic hydrocarbons are preferable. Specifically, dodecane, tetradecane, pentadecane, hexadecane, octadecane, nonadecane, eicosane, heneicosane, These are normal paraffins such as docosan, tetracosan, hexacosan, heptacosan, octacosan, and triacontane, isoparaffins that are various isoforms thereof, and various cycloparaffins that include a ring structure in a part of the molecule. More preferably a saturated aliphatic hydrocarbons C ₁₀ -C _30, in particular, n- tetradecane, n- pentadecane, n- hexadecane, n- octadecane, or mixtures thereof.
Needless to say, the phase change material can be used alone or in combination in consideration of the temperature and heat quantity to be taken out and the melting point of the phase change material.

The emulsifier for dispersing the phase change material in water is a combination of two types, a nonionic surfactant and an amphoteric surfactant.
Examples of the nonionic surfactant include the following compounds (1) to (6) and other known compounds. Among the following (1) to (6), the adduct of (1) to (3) is preferable (that is, polyoxyalkylene adduct of aliphatic alcohols, fatty acids, or polyoxyalkylene having an aromatic ring. Adducts are preferred; see invention 2).
(1) Polyoxyalkylene ether addition products to aliphatic alcohols, or polyoxyalkylene adducts having an aromatic ring
(2) Polyoxyalkylene ester addition products of fatty acids
(3) Ether addition product of aliphatic alcohol to polyoxyalkylene ester addition product of fatty acids
(4) Polyoxyalkylene ether addition products to polyhydric alcohols such as glycerin
(5) Ester addition products of fatty acids to polyoxyalkylene ether addition products of polyhydric alcohols such as glycerin
(6) Polyoxyalkylene addition product to castor oil or hydrogenated castor oil

In the ether addition product of polyoxyalkylene to aliphatic alcohols of (1) above, ethylene oxide (2 to 100 mol) and / or propylene oxide (1 to 10 mol) to C _{8 to} C ₂₂ aliphatic alcohols Specific examples include the mono and diether addition products. The following (a)-(d) etc. are as a commercial item of the aliphatic alcohol ether in said (1).
(a) FINESURF D system (polyoxyethylene decyl ether), BLAUNON EL system (polyoxyethylene lauryl ether), BLAUNON CH system (polyoxyethylene cetyl ether), BLAUNON SR system (polyoxyethylene stearyl ether), BLAUNON EN system (Polyoxyethylene oleyl ether), COCOSURF (polyoxyethylene coconut alcohol ether), COCOSURF HG (polyoxyethylene refined coconut alcohol ether): manufactured by Aoki Oil & Fat Co., Ltd.
(b) Emulgen 100 series (polyoxyethylene lauryl ether), Emulgen 200 series (polyoxyethylene cetyl ether), Emulgen 300 series (polyoxyethylene stearyl ether) series, Emulgen 400 series (polyoxyethylene stearyl ether), Emulgen 1100 (Polyoxyethylene alkyl ether) series, Emulgen 4085 (Polyoxyethylene myristyl ether), Emulgen 2020G-HA, 2025G (Polyoxyethylene octyldodecyl ether), Emulgen LS (Polyoxyalkylene alkylene alkyl ether): manufactured by Kao Corporation
(c) Arypon FT (polyoxyethylene lauryl ether), Euglegin B series (polyoxyethylene cetostearyl ether), Euglegin O series (polyoxyethylene oleyl cetyl ether): manufactured by Cognis Japan
(d) EMALEX 100 series (polyoxyethylene cetyl ether), EMALEX 500 series (polyoxyethylene oleyl ether), EMALEX 600 series (polyoxyethylene stearyl ether), EMALEX 700 series (polyoxyethylene lauryl ether), EMALEX 1600 series (Polyoxyethylene isocetyl ether), EMALEX 1800 (polyoxyethylene isostearyl ether), EMALEX OD series (polyoxyethylene octyldodecyl ether), EMALEX BHA (polyoxyethylene behenyl ether), EMALEX DAPE series (polyoxy Ethylene polyoxypropylene decyl ether): manufactured by Nippon Emulsion Co., Ltd.

  In addition, commercially available products of the polyoxyalkylene adduct having the aromatic ring of (1) include BLAUNON DSP, TSP (polyoxyethylene styrenated phenyl ether), BLAUNON PH (polyoxyethylene phenyl ether), BLAUNON BA. (Polyoxyethylene benzyl ether), BLAUNON BN (polyoxyethylene β-naphthyl ether), BLAUNON BEO (polyoxyethylene bisphenol A ether), BLAUNON BFE (polyoxyethylene bisphenol F ether) Kogyo Co., Ltd.).

Specific examples of the ester addition product of (2) above include mono- and diester addition products of ethylene oxide (2 to 100 mol) and / or propylene oxide (1 to 10 mol) to C _{12 to} C ₂₂ fatty acids. It is done. Examples of commercially available products of the ester addition product include the following (a) to (c).
(a) Emanon 1112 (polyoxyethylene monolaurate), Emanon 3199 (polyoxyethylene monostearate), Emanon 3299 and 3299V (polyoxyethylene distearate), Emanon 4110 (polyoxyethylene monooleate): Kao Made by Co., Ltd.
(b) BLAUNON L (polyoxyethylene monolaurate), BLAUNON S (polyoxyethylene monostearate), BLAUNON DS (polyoxyethylene distearate): manufactured by Aoki Oil & Fat Co., Ltd.
(c) EMALEX 800 series (polyethylene glycol monostearate), EMALEX OE series (polyethylene glycol monooleate), EMALEX 200 di-L (polyethylene glycol dilaurate), EMALEX 200 di-S, etc. (polyethylene glycol diisostearate) , EMALEX DEG-di-IS, etc. (polyethylene glycol diisostearate), EMALEX 200 di-O, etc. (polyethylene glycol dioleate): manufactured by Nippon Emulsion Co., Ltd.

In the ether addition product of (3) above, ether addition of aliphatic alcohols to ester addition products of ethylene oxide (2 to 100 mol) and / or propylene oxide (1 to 10 mol) of C _{12 to} C ₂₂ fatty acids. The product is given as a specific example. Commercially available products of the ether addition products include EMALEX CWS (stearic acid polyoxyethylene cetyl ether), EMALEX CWS (stearic acid polyoxyethylene stearyl ether), EMALEX SWS (stearic acid polyoxyethylene stearyl ether), Examples include EMALEX LWS (polyoxyethylene lauryl ether stearate) and EMALEX LWIS (polyoxyethylene lauryl ether isostearate) (both manufactured by Nippon Emulsion Co., Ltd.).

  Specific examples of the ether addition product of (4) above include mono, di, or triether addition products to ethylene oxide (2 to 40 mol) to polyhydric alcohols such as glycerin. Commercially available products of the ether addition products include BLAUNON GL (polyoxyethylene glycerol ether), BLAUNNTMP (polyoxyethylene trimethylol propane ether), BLAUNON 240 (polyoxyethylene sorbitol ether) (both Aoki Oil and Fat Industries ( Etc.).

In the ester addition product of (5) above, C ₁₂ -C ₂₂ fatty acid mono-, di- and triester addition products to ethylene oxide (2-100) ether addition products of polyhydric alcohols such as glycerin are examples. Can be mentioned. Commercially available products of the ester addition products include the following (a) to (b).
(a) BLAUNON PDO (polyoxyethylene pentaerythritol diolate), ST (polyoxyethylene sorbitan monostearate), OT (polyoxyethylene sorbitan monooleate): manufactured by Aoki Oil & Fat Co., Ltd.
(b) Cutina E24 (polystearic acid polyoxyethylene glycerin) Cognis Japan KK, EMALEX GM series (polystearic acid polyoxyethylene glycerin), EMALEX GWIS-300 series (polyisoethylene stearic acid polyoxyethylene glyceryl), EMALEX GWIS -100 series (polyoxyethylene glyceryl isostearate), EMALEX GWS-300 series (polyoxyethylene glyceryl tristearate), EMALEX GWS-204 (polyoxyethylene glyceryl distearate), EMALEX GWS-300 series (polytrioleic acid poly) Oxyethylene glyceryl): manufactured by Nippon Emulsion Co., Ltd.

Among the addition products of (6) above, ethylene oxide addition products to castor oil or hydrogenated castor oil are preferred, and commercially available products include the following (a) to (d).
(a) BLAUNON BR type (polyoxyethylene castor oil), BLAUNON CW type and BLAUNON RCW type (polyoxyethylene hydrogenated castor oil): manufactured by Aoki Oil & Fat Co., Ltd.
(b) Emanon CH (polyoxyethylene hydrogenated castor oil): manufactured by Kao Corporation
(c) Euglegine HRE (polyoxyethylene hydrogenated castor oil): Cognis Japan Co., Ltd.
(d) EMALEX HC system (polyoxyethylene hydrogenated castor oil), EMALEX C (polyoxyethylene castor oil), EMALEX RWIS-100 system (isostearic acid polyoxyethylene hydrogenated castor oil), EMALEX RWIS-300 system (triisostearic acid) Polyoxyethylene hydrogenated castor oil), EMALEX RWL-100 series (polyoxyethylene hydrogenated castor oil laurate): manufactured by Nippon Emulsion Co., Ltd.

As the other amphoteric surfactant of the emulsifiers, alkyl or alkenyl betaine type, alkyl or alkenyl amide betaine type, alkyl or alkenyl sulfobetaine type, alkyl or alkenyl amide sulfobetaine type, imidazoline type, amino acid type, amine oxide type Compound etc. are mentioned. The amino acid type includes β-alanine type and (alkyl) amino fatty acid type.
Among amphoteric surfactants, betaine type, amino acid type and imidazoline type are preferable (see the present invention 3). Among these, specific examples of the betaine type include an alkyl or alkenyl betaine type, an alkyl or alkenyl amide betaine type, an alkyl or alkenyl sulfobetaine type, and an alkyl or alkenyl amide sulfobetaine type.

The betaine-type commercial products include the following (a) to (f).
(a) Enadicol C-30B (coconut oil fatty acid amidopropyl betaine solution), Enadicol L-30B (lauric acid amidopropyl betaine solution): manufactured by Lion Corporation
(b) Amhitor 20BS and 24B (lauryl betaine), Amhitor 86B (stearyl betaine): manufactured by Kao Corporation
(c) Genegen (Betaine): manufactured by Clariant Japan
(d) DEHITONE AB30 (Lauryldimethylaminoacetic acid betaine), DEHITONE K (palm fatty acid amidopropyl betaine liquid), DEHITON L12 (lauric acid amidopropyl betaine liquid): Cognis Japan Co., Ltd.
(e) Amipol NO-6S and Amipol S (betaine surfactant): manufactured by Nikka Chemical Co., Ltd.
(f) Softazoline CPB (coconut oil fatty acid amide propyl betaine liquid), softazolin LPB (lauric acid amidopropyl betaine liquid), softazolin MPB (myristate amidopropyl betaine liquid), softazolin PKPB (palm kernel oil fatty acid amidopropyl betaine liquid): Made by Kawaken Fine Chemical Co., Ltd.

Examples of the commercial products of the sulfobetaine type include SOFTAZOLIN LSB (lauramide amidopropyl hydroxysulfobetaine solution: manufactured by Kawaken Fine Chemical Co., Ltd.).
The commercially available products of the amino acid type include the following (a) to (b).
(a) Enadicol CNS (N-coconut oil fatty acid acyl-N′-carboxyethyl-N′-hydroxyethylethylenediamine sodium): manufactured by Lion Corporation
(b) Softazoline NS and SF (N-coconut oil fatty acid acyl-N'-carboxyethyl-N'-hydroxyethylethylenediamine sodium), softazoline OSF (oleyl-N-carboxyethyl-N-hydroxyethylethylenediamine sodium), softazoline PKNS (Palm kernel oil fatty acid acyl-N-carboxyethyl-N-hydroxyethylethylenediamine sodium): Kawaken Fine Chemical Co., Ltd.

The imidazoline-type commercial products include the following (a) to (c).
(a) Amhitoal 20YB (2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine): manufactured by Kao Corporation
(b) Enadicol C-40H (2-alkyl-N′-carboxymethyl-N-hydroxyethylimidazolinium betaine): manufactured by Lion Corporation
(c) Softazoline CL (2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine), softazoline HL (N-lauroyl-N'-carboxymethyl-N'-hydroxyethylethylenediamine sodium), softazoline CH ( 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine): manufactured by Kawaken Fine Chemical Co., Ltd.

The amine oxide type commercial products include the following (a) to (b).
(a) Amphital 20N (lauryl dimethylamine oxide): manufactured by Kao Corporation
(b) Standamox C1214 (lauryl dimethylamine oxide solution), O1 (oleyl dimethylamine oxide): manufactured by Cognis Japan
(c) Softazoline LAO (Lauric acid amidopropylamine oxide solution): Kawaken Fine Chemical Co., Ltd.

The nonionic surfactants and amphoteric surfactants can be used alone or in combination.
Further, as a preferred combination of nonionic and amphoteric surfactants, a combination of a polyoxyalkylene adduct of an aliphatic alcohol and an amino acid type surfactant is exemplified as shown in the present invention 5. Examples of the polyoxyalkylene adduct of aliphatic alcohols include polyoxyethylene lauryl ether and polyoxyethylene stearyl ether. Examples of the amino acid type surfactant include N-coconut oil fatty acid acyl-N′-carboxyethyl-N′-hydroxyethylethylenediamine sodium, oleyl-N-carboxyethyl-N-hydroxyethylethylenediamine sodium, and the like.

The present invention is characterized in that nonionic and amphoteric surfactants are used in combination as emulsifiers. These surfactants can be mixed in an arbitrary ratio, but basically it is appropriate that the weight ratio of the main component nonionic surfactant is larger than that of the auxiliary amphoteric surfactant.
The mixing ratio (weight ratio) of the nonionic surfactant and the amphoteric surfactant is suitably amphoteric / nonionic property = 1/9 to 1/1, preferably 1/4 to 1/2, more preferably Is around 1/3. Amphoteric / Nonionicity = Even if it is less than 1/9 or exceeds 1/1, it is easy to impair the emulsion stability accompanying the temperature change. It is important to mix within the range (see test examples below).
The nonionic surfactant and the amphoteric surfactant may be mixed in advance and added to the emulsifying system, or may be added separately to the emulsifying system.
Moreover, the addition rate of the said phase change substance with respect to the whole emulsification system containing water needs to be 10 to 70 weight%, and 30 to 60 weight% is preferable. If it is less than 10% by weight, the heat storage efficiency is lowered, and if it exceeds 70% by weight, the ratio of water is lowered, the oil-in-water emulsion becomes unstable, and there is a risk of phase inversion into the water-in-oil emulsion.
The addition ratio of the above-mentioned emulsifier with respect to 100 parts by weight of the phase change material is 0.5 to 200 parts by weight, and preferably 3 to 20 parts by weight. If the amount is less than 0.5 parts by weight, the production of an aqueous emulsion is hindered. If the amount exceeds 200 parts by weight, the cost increases, and the proportion of substances that do not contribute to the amount of heat increases, resulting in insufficient heat.

In the emulsion type heat storage material of the present invention, a high viscosity type heat storage material can be prepared by adding a thickener to the emulsification system. The high-viscosity heat storage material is advantageous in that, even when the packaging bag containing the heat storage material is damaged, there is little contamination of the surroundings due to outflow, and the heat storage material can be uniformly present in the packaging bag.
The thickener is preferably a polymer compound that is easily dissolved in water. For example, gum arabic, arginine carbomer, alginic acid, sodium alginate, propylene glycol alginate, ethyl cellulose, sodium carboxymethylcellulose, xanthan gum, synthetic sodium silicate / magnesium, dimethyl Examples include distearyl ammonium hectorite, cyclodextrin, polyacrylic acid, sodium polyacrylate, and (meth) acrylic acid copolymer.
Among these thickeners, when adding an acid-type thickener (alginic acid, polyacrylic acid, etc.) to prepare a high-viscosity heat storage material, one of the emulsifier surfactants, betaine-type, imidazoli When a quaternary ammonium salt type surfactant such as a nium betaine type is used, thickening is not sufficient only by adding a thickening agent, and neutralization by adding an alkaline solution such as aqueous sodium hydroxide, aqueous ammonia or amines. Work is required, but amphoteric surfactants that are tertiary amines such as amino acid type and have a salt (eg, sodium salt) structure at the molecular end can be thickened only by adding a thickener. The neutralization operation can be omitted and the productivity of the heat storage material can be improved.
Moreover, in order to add a thickener to an emulsification system, you may add at the below-mentioned emulsification process, and may add after emulsification. However, when a thickener is added after the emulsification step, the various polymer thickeners are preferably in the form of an aqueous solution or an emulsion from the viewpoint of quick and uniform mixing with the heat storage material emulsion. However, emulsions such as poly (meth) acrylic acid are particularly desirable.
Commercially available products of this aqueous solution or emulsion type thickener include the following (a) to (d).
(a) Aron A-20L (sodium polyacrylate), Aron A-7180 (carboxylic acid copolymer sodium salt): manufactured by Toagosei Co., Ltd.
(b) Jurimer AC-103 (sodium polyacrylate), Jurimer AC10-S (polyacrylic acid): manufactured by Nippon Pure Chemical Co., Ltd.
(c) AQUALIC DL series (sodium polyacrylate), AQUALIC TL series (acrylic acid / maleic acid copolymer salt), AQUALIC HL series (polyacrylic acid), Aron B-300K (carboxylic acid-based copolymer weight) Coalescence), Aron A-7070 (carboxylic acid copolymer): manufactured by Toagosei Co., Ltd.
(d) Primal ASE-60 (polyacrylic acid): manufactured by Rohm and Haas Japan Co., Ltd.

As shown in the present invention 8, when producing an emulsion-type heat storage material, a supercooling inhibitor (also referred to as an ice nucleating agent) is added to the emulsification system from the viewpoint of preventing a supercooling phenomenon that causes a reduction in thermal efficiency. Is effective.
As the supercooling inhibitor, known amines, alcohols, carboxylic acids, and saturated hydrocarbons can be used, but they have a higher melting point than phase change materials (that is, they can cause solidification from an early stage). Saturated aliphatic hydrocarbons having good compatibility with phase change materials are preferred (see the present invention 9).
As shown in the present invention 8, among the saturated aliphatic hydrocarbons, paraffin wax which is a mixture of plural kinds of saturated aliphatic hydrocarbons is more preferable.
Various products are commercially available depending on the melting point of the paraffin wax, but various paraffin waxes including specially refined products can be used singly or in combination in consideration of the melting point and compatibility of the phase change material used. Representative products include refined paraffin wax commercially available from Nippon Seiwa, ExxonMobil Chemical, Esso Petroleum, etc., highly purified paraffin wax, and specially refined paraffin wax mainly composed of isoparaffin.
In addition, unlike the known amines, alcohols, carboxylic acids and the like, the paraffin wax has an advantage that it has suitability for a heat storage material and contributes to an increase in heat quantity in combination with a phase change material. .

The emulsion-type heat storage material of the present invention is produced by emulsifying and dispersing a phase change material using an emulsifier, and further, if necessary, a thickener and a supercooling inhibitor in water (the thickener is As mentioned above, it may be added after the emulsification step).
This emulsification dispersion can be arbitrarily selected from known methods such as a high-pressure emulsification method and a phase inversion emulsification method.
In the high pressure emulsification method, first, emulsified water in which an emulsifier is dissolved in water is added to a mixture of the phase change material and the supercooling inhibitor, and premixed to form coarse particles. This is a fine emulsification method using a high-pressure emulsifier, a high-pressure discharge type emulsifier, a high shear type emulsifier-disperser, or the like.
In the phase inversion emulsification method, the emulsifier to be used is sufficiently kneaded to the mixture of the phase change material, the supercooling inhibitor, etc., and then water is gradually added while stirring to convert the water-in-oil emulsion into an oil-in-water This is a method of phase inversion to an emulsion.

If necessary, the emulsion-type heat storage material of the present invention may be added with various additives such as antifreezing agents such as ethylene glycol, polyethylene glycol and various inorganic salts, preservatives, dispersants and antifoaming agents. it can.
The emulsion-type heat storage material of the present invention is suitable for heat storage for heating and cooling of buildings, houses, etc., freezing and refrigeration of foods, or heat transfer systems.

Hereinafter, examples of production of the emulsion-type heat storage material (including the high-viscosity heat storage material) of the present invention and test examples such as emulsion stability with respect to temperature change and heat quantity evaluation by the heat storage material obtained in the examples will be sequentially described. “Parts” and “%” in Examples and Test Examples are based on weight.
The present invention is not limited to the following examples and test examples, and it is needless to say that arbitrary modifications can be made within the scope of the technical idea of the present invention.

<< Embodiment example of emulsion type heat storage material >>
Among Examples 1 to 18, odd-numbered Example 2n + 1 (n = 0 to 8) is an example of an emulsion-type heat storage material to which no thickener is added, and even-numbered Example 2n + 2 (n = 0 to 8) is increased. It is an example of a high-viscosity heat storage material to which a viscosity agent is added. For example, a composition excluding the presence or absence of addition of a thickener in a pair of examples where n = 0, that is, Example 1 and Example 2. Are common (hereinafter, the same applies when n = 1 to 8). In Examples 1 to 18, the types of nonionic and amphoteric surfactants and the mixing ratio (weight) were changed and combined. Examples 1 to 10 are examples in which the weight ratio of nonionicity and amphoteric surfactant is amphoteric / nonionicity = 1/3, and Examples 11 to 14 are examples in which amphoteric / nonionicity = 1 / 3.5. Examples 15 to 16 are examples of amphoteric / nonionic properties = 1/1, and Examples 17 to 18 are examples of amphoteric / nonionic properties = 20/1.
Comparative Example 1 is a blank example in which only a nonionic surfactant is used and no amphoteric surfactant is added, and Comparative Example 2 is an example in which a thickener is added with the same composition. Comparative Example 3 is a blank example in which only an amphoteric surfactant is used and no nonionic surfactant is added, and Comparative Example 4 is an example in which a thickener is added with the same composition. Comparative Example 5 is a combination of nonionic and anionic surfactants, and is an example based on the aforementioned Patent Documents 1, 2, 5, etc., and Comparative Example 6 is an example in which a thickener is added with the same composition. It is.
In addition, the composition of phase change substances and emulsifiers in the examples with odd numbers, the types of nonionic and amphoteric surfactants in the emulsifier, the mixing ratio, and the like are summarized in FIG. FIG. 2 is an equivalent diagram of a high-viscosity heat storage material to which a thickener is similarly added. The ice nucleating agent in FIGS. 1-2 means a supercooling inhibitor.

(1) Example 1
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts, 1.6 parts of polyoxyethylene stearyl ether (20E.O.) (Nippon Emulsion Co., Ltd .: EMALEX 620) as a nonionic surfactant are dissolved and uniformly dissolved. Mixed.
In addition, as an amphoteric surfactant, 1.8 parts of lauric acid amidopropyl betaine solution (manufactured by Kawaken Fine Chemical Co., Ltd .: Softazoline LPB) is dissolved in 42.8 parts of ion-exchanged water to obtain an aqueous surfactant solution. Was prepared.
Then, this aqueous surfactant solution was added to a mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.
In Example 1, 1.6 parts of a nonionic surfactant (polyoxyethylene alkyl ether) with a solid content of 100% and 1.8 parts of an amphoteric surfactant (betaine type) with a 30% solution were mixed. Therefore, the mixing ratio (weight ratio) of nonionicity and amphoteric surfactant is amphoteric / nonionicity = (1.8 × 30%) / 1.6 = 1/3.

(2) Example 2
After performing the same operation as in Example 1, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the obtained high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

(3) Example 3
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts, 1.6 parts of polyoxyethylene stearyl ether (20E.O.) (Nippon Emulsion Co., Ltd .: Emalex 620) as nonionic surfactant is dissolved. Mix evenly.
Further, as an amphoteric surfactant, 1.8 parts of lauric acid amidopropyl hydroxysulfobetaine solution (manufactured by Kawaken Fine Chemical Co., Ltd .: Softazoline LSB) is dissolved in 42.8 parts of ion-exchanged water to obtain a surface activity. An aqueous agent solution was prepared.
Then, this aqueous surfactant solution was added to a mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.

(4) Example 4
After performing the same operation as in Example 3, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the obtained high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

(5) Example 5
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts, 1.6 parts of polyoxyethylene stearyl ether (20E.O.) (Nippon Emulsion Co., Ltd .: EMALEX 620) as a nonionic surfactant are dissolved and uniformly dissolved. Mixed.
Moreover, 1.8 parts of N-coconut oil fatty acid acyl-N'-carboxyethyl-N'-hydroxyethylethylenediamine sodium solution (manufactured by Kawaken Fine Chemical Co., Ltd .: Softazoline NS) as an amphoteric surfactant is ionized. A surfactant aqueous solution was prepared by dissolving in 42.8 parts of exchange water.
Then, this aqueous surfactant solution was added to a mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.

(6) Example 6
After performing the same operation as in Example 5, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the obtained high-pressure emulsion 2 0.0 part was added and mixed to obtain a high-viscosity heat storage material.

(7) Example 7
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts, 1.6 parts of polyoxyethylene stearyl ether (20E.O.) (Nippon Emulsion Co., Ltd .: EMALEX 620) as a nonionic surfactant are dissolved and uniformly dissolved. Mixed.
Further, 1.3 parts of a 2-alkyl-N′-carboxymethyl-N-hydroxyethylimidazolinium betaine solution having a content of 40% as an amphoteric surfactant (manufactured by Kao Corporation: Amphitol 20YB) was added to 43 parts of ion-exchanged water. A surfactant aqueous solution was prepared by dissolving in 2 parts.
Then, this aqueous surfactant solution was added to a mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.

(8) Example 8
After performing the same operation as in Example 7, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the obtained high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

(9) Example 9
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts and 1.6 parts of polyoxyethylene stearyl ether (20E.O.) (Nippon Emulsion Co., Ltd .: Emalex 620) as nonionic surfactant are dissolved. Mix evenly.
Also, an aqueous surfactant solution was prepared by dissolving 1.5 parts of 35% lauryldimethylamine oxide (Kao Co., Ltd .: Amphital 20N) as an amphoteric surfactant in 43.0 parts of ion-exchanged water.
Then, this aqueous surfactant solution was added to a mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.

(10) Example 10
After performing the same operation as in Example 9, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the obtained high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

(11) Example 11
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts, 1.6 parts of polyoxyethylene hydrogenated castor oil (40E.O.) (Kao Co., Ltd .: Emanon CH-40) as nonionic surfactant is dissolved. And mixed uniformly.
In addition, 1.8 parts of N-coconut oil fatty acid acyl-N′-carboxyethyl-N′-hydroxyethylethylenediamine sodium (manufactured by Kawaken Fine Chemical Co., Ltd .: Softazoline NS) as an amphoteric surfactant is ion-exchanged. A surfactant aqueous solution was prepared by dissolving in 42.8 parts of water.
Then, this aqueous surfactant solution was added to a mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.

(12) Example 12
After performing the same operation as in Example 11, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the resulting high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

(13) Example 13
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ) Manufactured: Paraffin wax-155) 10.8 parts, polyoxyethylene monolaurate (12E.O.) (non-ionic surfactant) (Eamon 1112 manufactured by Kao Co., Ltd.) 1.6 parts are dissolved and uniform. Mixed.
Also, 1.8 parts of N-coconut oil fatty acid acyl-N'-carboxyethyl-N'-hydroxyethylethylenediamine sodium (manufactured by Kawaken Fine Chemical Co., Ltd .: Softazoline NS) as an amphoteric surfactant is ion-exchanged. A surfactant aqueous solution was prepared by dissolving in 42.8 parts of water.
Then, this aqueous surfactant solution was added to a mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.

(14) Example 14
After performing the same operation as in Example 13, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the obtained high-pressure emulsion 2 0.0 part was added and mixed to obtain a high-viscosity heat storage material.

(15) Example 15
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts, 1.1 parts of polyoxyethylene stearyl ether (20E.O.) (Nippon Emulsion Co., Ltd .: EMALEX 620) as nonionic surfactant is dissolved and uniformly dissolved. Mixed.
Further, 3.6 parts of lauric acid amidopropyl betaine solution (manufactured by Kawaken Fine Chemical Co., Ltd .: Softazoline LPB) as an amphoteric surfactant is dissolved in 41.5 parts of ion-exchanged water to obtain an aqueous surfactant solution. Was prepared.
Then, this aqueous surfactant solution was added to a mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.

(16) Example 16
After performing the same operation as in Example 11, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the resulting high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

(17) Example 17
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts, 0.1 part of polyoxyethylene stearyl ether (20E.O.) (Nippon Emulsion Co., Ltd .: EMALEX 620) as nonionic surfactant is dissolved and uniformly dissolved. Mixed.
Further, 6.7 parts of a 30% lauric acid amidopropyl betaine solution (manufactured by Kawaken Fine Chemical Co., Ltd .: Softazoline LPB) as an amphoteric surfactant is dissolved in 39.3 parts of ion-exchanged water to obtain an aqueous surfactant solution. Was prepared.
Then, this aqueous surfactant solution was added to a mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.
In Example 17, 0.1 part of a nonionic surfactant (polyoxyethylene alkyl ether) having a solid content of 100% and 6.7 parts of an amphoteric surfactant (betaine type) in a 30% solution were mixed. Therefore, the mixing ratio (weight ratio) of nonionicity and amphoteric surfactant is amphoteric / nonionicity = (6.7 × 30%) / 0.1 = 20/1.

(18) Example 18
After performing the same operation as in Example 17, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the obtained high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

(19) Comparative Example 1
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts, 2.2 parts of polyoxyethylene stearyl ether (20E.O.) (Nippon Emulsion Co., Ltd .: EMALEX 620) as nonionic surfactant is dissolved and uniformly dissolved. Mixed.
Next, 44.0 parts of this ion-exchanged water was added to the mixed solution of the phase change material, the supercooling inhibitor and the nonionic surfactant, and the mixture was stirred and pre-emulsified. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.

(20) Comparative Example 2
After performing the same operation as in Comparative Example 1, the polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the obtained high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

(21) Comparative Example 3
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts was dissolved and mixed uniformly.
Moreover, 7.2 parts of lauric acid amidopropyl betaine solution (Kawaken Fine Chemical Co., Ltd .: Softazoline LPB) having a content of 30% as an amphoteric surfactant was dissolved in 39.0 parts of ion-exchanged water to obtain an aqueous surfactant solution. Was prepared.
Then, this surfactant aqueous solution was put into a mixed solution of the phase change material and the supercooling inhibitor, and the mixture was stirred and mixed to perform preliminary emulsification. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.

(22) Comparative Example 4
After performing the same operation as in Comparative Example 3 above, polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 with respect to 100 parts of the obtained high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

(23) Comparative Example 5
43.1 parts of an n-paraffin mixture having a melting point of about 25 ° C. (Japan Energy Co., Ltd .: Cactus normal paraffin TS-897) as a phase change material, and paraffin wax having a melting point of 69 ° C. (Nippon Seiwa Co., Ltd.) ): Paraffin wax-155) 10.8 parts, 1.6 parts of polyoxyethylene stearyl ether (20E.O.) (Nippon Emulsion Co., Ltd .: EMALEX 620) as a nonionic surfactant are dissolved and uniformly dissolved. Mixed.
Also, 2.2 parts of a polyoxyethylene alkyl ether sulfosuccinic acid half-ester disodium salt aqueous solution having a content of 24% as an ionic surfactant (manufactured by Nippon Shokubai Co., Ltd .: Softanol MES-9) is added to 42.3 parts of ion-exchanged water. A surfactant aqueous solution was prepared.
Then, this surfactant aqueous solution was put into a mixed solution of the phase change material and the supercooling inhibitor, and the mixture was stirred and mixed to perform preliminary emulsification. The obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier manufactured by Menton Gaurin at a pressure of 300 kg / cm ² to obtain an emulsion-type heat storage material.
The mixing ratio (weight ratio) of nonionic and anionic in Comparative Example 5 is anionic / nonionic = (2.2 × 24%) / 1.6 = 1/3, and the present invention The nonionicity and the amphoteric ratio in the preferable ratio range (1/9 to 1/1) were adjusted.

(24) Comparative Example 6
After performing the same operation as in Comparative Example 5 above, polyacrylic acid type thickener (Primal ASE-60: manufactured by Rohm and Haas Japan Co., Ltd.) 2 for 100 parts of the resulting high-pressure emulsion 2 Add 0.0 parts and mix. Next, a 10% aqueous sodium hydroxide solution was added to adjust the pH to 7, thereby obtaining a high-viscosity heat storage material.

<< Evaluation test example of emulsion-type heat storage material >>
Therefore, each emulsion-type heat storage material obtained in odd-numbered Example 2n + 1 (n = 0 to 8) and odd-numbered Comparative Example 2n + 1 (n = 0 to 2) (that is, low viscosity without adding a thickener). Various evaluation tests were performed on the heat storage material in the form of an emulsion by the following methods.
(a) Calorie measurement of heat storage material A differential scanning calorimeter was used to raise the temperature from −10 ° C. to 65 ° C. at a rate of temperature rise of 5 ° C./min, and the amount of latent heat was measured.

(b) Emulsion stability test by repeated cooling and heating of the heat storage material The appearance of the heat storage material was evaluated by visual observation by repeated cooling and heating in which the temperature was changed to 40C. The standard is as follows.
○: The state of the heat storage material did not change and was stable even when the number of repetitions of cooling and heating exceeded 100 times during the test.
(Triangle | delta): During the test, by the time of repetition of cooling and heating exceeding 100 times, the emulsion of the heat storage material was destroyed, the oil phase and the water phase were separated, and phase separation occurred.
X: During the test, the emulsion of the heat storage material was broken, and the oil phase and the water phase were separated and phase separation occurred until the cooling / heating cycle exceeded 10 times.

The lower two columns in FIG. 1 show the evaluation test results.
In Comparative Example 2 using only the amphoteric surfactant, the emulsion was broken up to 10 times, and in Comparative Example 1 using only the nonionic property, the emulsion was broken up to 100 times of the cooling / heating cycle. In Comparative Example 3 using both nonionicity and anionicity, the evaluation was the same as in Comparative Example 1.
On the other hand, in the odd-numbered examples in which nonionic and amphoteric surfactants were used in combination, the stability of the emulsion was destroyed by 100 times in Examples 9 and 17, but all the others exceeded 100 times. Even the emulsion was kept stable.
From the above points, in the comparative example in which only one of the nonionic and amphoteric surfactants is used as the emulsifier, or the nonionic and anionic properties are used together, the emulsion stability with respect to the temperature change of the emulsion-type heat storage material is considerably high. Although it is inferior or insufficient, it has become clear that Examples in which both nonionicity and amphotericity are used in combination with these comparative examples have a remarkable advantage in terms of emulsion stability.

Examining the examples in detail, in Example 9, since amine oxide was used as the amphoteric surfactant, the evaluation of stability with respect to temperature change was backward compared to the other examples. Thus, it has been found that it is preferable to use a betaine type (including sulfobetaine type), an amino acid type, and an imidazoline type for both sexes for improving the stability.
Moreover, in Example 17, since the mixing ratio of nonionicity and amphoteric was inclined to be amphoteric, evaluation of stability was backward compared with other examples. As described above, in the combined use method of the emulsifier of the present invention, since the nonionicity is the main and the amphoteric is auxiliary, the mixing ratio is preferably about amphoteric / nonionicity = 1/9 to 1/1, and the amphoteric is nonionic. It was confirmed that the contribution to emulsion stability is reduced when the amount is more than the surfactant.
On the other hand, in the calorie | heat amount evaluation, it was confirmed that the emulsion type thermal storage material of an Example has high thermal efficiency. However, in calorimetric evaluation, there was not much difference between Examples and Comparative Examples.

<< Evaluation test example of high viscosity heat storage material >>
Then, each high-viscosity heat storage material (ie, thickener) obtained in even-numbered Example 2n + 2 (n = 0-8) and even-numbered Comparative Example 2n + 2 (n = 0-2) was added. Various evaluation tests were performed by the following methods for the high viscosity (paste-like heat storage material) obtained by summing.
(a) Stability test by repeated cooling and heating First, 20 g of each high-viscosity heat storage material was packed in a low-density polyethylene bag (7.5 cm × 12 cm), and the bag was fused.
Then, the appearance of the heat storage material was visually observed through repeated cooling and heating operations to change the temperature to 5 ° C. and 40 ° C., and the stability was evaluated. The standard was the same as in the case of the emulsion-type heat storage material, and the evaluation was made in three stages of ○, Δ, and ×.

(b) Evaluation of operability when adding a thickener In a high-viscosity heat storage material, it was necessary to add a thickener to the emulsion-type heat storage material to increase the viscosity. Thickening with only addition, or thickening without adding thickener alone, neutralizing and thickening by adding neutralizer (specifically, 10% aqueous sodium hydroxide) The operability was confirmed and evaluated whether or not neutralization operation was necessary.

The third and bottom columns from the bottom of FIG. 2 are the evaluation test results.
In the evaluation test of emulsion stability by repeated cooling and heating, the evaluation is almost the same as that of an emulsion-type heat storage material, and even-numbered examples using both nonionic and amphoteric surfactants are one of nonionic and amphoteric surfactants. The evaluation was superior to Comparative Examples 2 and 4 in which only the surfactant was used alone, or Comparative Example 6 in which other surfactants were combined (a combination of nonionic and anionic properties).
However, the stability evaluation of Examples 12 and 14 using polyoxyethylene hydrogenated castor oil and polyoxyethylene monolaurate as the nonionic surfactant is as in Example 10 using amine oxide as the amphoteric surfactant, It was the same level as Example 18 in which amphoteric surfactant was excessively added compared to nonionic property, and the stability due to repeated cooling and heating was retreated compared to other even-numbered examples.
In addition, in the presence or absence of a neutralizing agent when adding a thickener (operability evaluation), amphoteric surfactants include betaine type (including alkylamidobetaine and sulfobetaine), imidazoline type, or amine oxide type. In Examples 2, 4, 8, 10, 16 or 18 in which neutralization was used, neutralization was necessary, but in Examples 6, 12 or 14 in which an amino acid type in which the carboxyl group formed a sodium salt structure was used, It has been clarified that the preparation work of the high-viscosity heat storage material can be simplified by using the amino acid type for both sexes, since the sum work is unnecessary.

Addition composition of phase change material, nonionic surfactant, amphoteric surfactant, supercooling inhibitor, etc., and stability against heat quantity and temperature change in each emulsion type heat storage material of odd numbered examples and odd numbered comparative examples It is a chart which shows the result of various evaluation tests. It is the equivalent figure of FIG. 1 of each high-viscosity heat storage material in the even-numbered example and the even-numbered comparative example.

Claims (9)

In a method for producing an emulsion-type heat storage material in which a phase change material is dispersed in water using an emulsifier,
The emulsifier is a nonionic surfactant and an amphoteric surfactant,
The addition ratio of the phase change material to the whole emulsification system containing water is 10 to 70% by weight, and the total addition amount of the emulsifier to 100 parts by weight of the phase change material is 0.5 to 200 parts by weight. A method for producing an emulsion-type heat storage material.   The nonionic surfactant is a polyoxyalkylene adduct of aliphatic alcohols, fatty acids, or a polyoxyalkylene adduct having an aromatic ring, The emulsion-type heat storage material according to claim 1, Method.   The method for producing an emulsion-type heat storage material according to claim 1 or 2, wherein the amphoteric surfactant is at least one of betaine-type, amino acid-type, and imidazoline-type surfactants.   The weight mixing ratio of the nonionic surfactant and the amphoteric surfactant is amphoteric surfactant / nonionic surfactant = 1/9 to 1/1. The manufacturing method of the emulsion-type heat storage material as described in claim | item.   The nonionic surfactant is a polyoxyalkylene adduct of aliphatic alcohols, and the amphoteric surfactant is an amino acid type surfactant. Manufacturing method of emulsion type heat storage material.   A thickener is added to an emulsification system, The manufacturing method of the emulsion-type heat storage material of any one of Claims 1-5 characterized by the above-mentioned. Phase change material, normal paraffins C ₈ -C _40, isoparaffins, any one of the preceding claims, characterized in that at least one cycloaliphatic selected from the group consisting of paraffin hydrocarbons A method for producing an emulsion-type heat storage material as described in 1.   The method for producing an emulsion-type heat storage material according to any one of claims 1 to 7, wherein a supercooling inhibitor is further added to the emulsification system.   The method for producing an emulsion-type heat storage material according to claim 8, wherein the supercooling inhibitor is an aliphatic hydrocarbon having a melting point higher than that of the phase change material and good compatibility with the phase change material.

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