JP4302500B2 - Emulsion composition for heat storage material - Google Patents

Description

  The present invention is a cold storage heat that accumulates power energy during off-peak hours of electric power demand using latent heat of fusion during phase change in order to eliminate the power shortage caused by the rapid increase in the use of air conditioning accompanying changes in the living environment. Related to system application technology. More particularly, the present invention relates to a latent heat type heat storage material emulsion composition comprising n-paraffin water comprising a linear saturated hydrocarbon and a specific emulsifier composition.

  In recent years, the use of air conditioning in office buildings and homes has been increasing, but in preparation for the peak power demand in the summer, the development of heat storage materials that accumulate cold energy for air conditioning using nighttime power has become active. . As heat storage materials, compounds that can utilize heat absorption and exothermic phenomena associated with phase change, such as compositions composed of hydrocarbon compounds such as n-paraffins and water, are widely used.

  As a method of mixing a heat storage material with water, there is a method of microencapsulation. However, there are disadvantages that the cost is high and the capsule strength is weak and easily deteriorates. On the other hand, in the method of emulsifying, an emulsion composition that forms a stable uniform dispersion system is obtained by using paraffin, water and a surfactant as heat storage components. Emulsification can increase the amount of heat transported per unit flow rate of fluid latent heat transfer, and the resulting benefits include (1) promotion of heat transfer, (2) reduction of pipe diameter, (3) pump Reduction of power, (4) reduction of pressure loss accompanying flow, and the like are mentioned.

Under such circumstances, many emulsion compositions for heat storage materials have been proposed. For example, in Patent Documents 1 to 5, emulsion compositions for heat storage materials comprising n-paraffin, water, and a surfactant as heat storage components having fluidity are proposed. However, Patent Document 6 discloses an emulsion composition for a heat storage material using n-paraffin having a single carbon number and α-olefin. However, in any case, there is a great room for improvement in heat storage performance, emulsion stability, cycle test, viscosity, addition amount, and the like.
JP 57-40582 (1-2 pages) JP-A-7-126614 (1-2 pages) JP 9-255944 (2-4 pages) JP 2000-336350 (2-3 pages) JP2003-321684 (2-5 pages) JP-A-9-13022 (1-2 pages)

  An object of the present invention is to provide an emulsion composition for a heat storage material that exhibits excellent emulsification dispersibility and emulsification stability by using a small amount of emulsifier, has a low viscosity, and has a large endothermic and large calorific value.

As a result of diligent research to solve the above-mentioned problems, the present inventors have found that a specific salt of styrene / maleic anhydride copolymer, a specific polyoxyalkylene alkyl ether phosphate, and a necessary salt are necessary in the preparation of an emulsion for a heat storage material. Accordingly, the present inventors have found that an emulsifier composition containing a polyoxyethylene glycerol borate fatty acid ester at a certain ratio is excellent in emulsifying property and has a large endothermic and exothermic amount accompanying a phase change.
That is, the present invention provides an emulsifier for obtaining an emulsion composition for a heat storage material containing 10 to 70 parts by weight of n-paraffin and 90 to 30 parts by weight of water (however, the total of n-paraffin and water is 100 parts by weight). (A) Styrene / maleic anhydride copolymer salt 40-70 wt%, (B) polyoxyalkylene alkyl ether phosphate 30-60 wt%, (C) polyoxyethylene glycerol borate fatty acid ester 0-30 wt% The emulsion composition for a heat storage material is characterized by using 0.2 to 20.0 parts by weight of a mixture blended at a ratio of% to 100 parts by weight of the total amount of n-paraffin and water.

  As a preferred embodiment of the present invention, the salt of the (A) styrene / maleic anhydride copolymer is a raw material resin having an average acid value of 265 to 495, ammonia, an organic amine, a monovalent alkali metal hydroxide, There is an emulsion composition for a heat storage material which is a salt partially or completely neutralized with a monovalent alkali metal salt.

（但し式中、Ｒ^１は炭素数６〜１８の直鎖もしくは分岐鎖のアルキル基又はアルケニル基又は炭素数８〜１８のアルキル基を有するアルキルフェニル基を示し、（ＡＯ）ｘはＡがエチレン基及び／又はプロピレン基から成る（ポリ）アルキレンオキサイド基を示す。ｘは０〜３０の整数、ｙは１又は２、ｚはｙ＋ｚ＝３の関係を満たす整数を示す。Ｍは水素原子もしくは１価に金属原子、アンモニア、有機アミンを示す。）で表される化合物である上記蓄熱材用エマルション組成物がある。 In another preferred embodiment of the present invention, the (B) polyoxyalkylene alkyl ether phosphate is represented by the following general formula (B):

(In the formula, R ¹ represents a linear or branched alkyl group having 6 to 18 carbon atoms or an alkenyl group or an alkylphenyl group having an alkyl group having 8 to 18 carbon atoms, and (AO) x represents that A is ethylene. A (poly) alkylene oxide group comprising a group and / or a propylene group, x is an integer of 0 to 30, y is 1 or 2, and z is an integer satisfying a relationship of y + z = 3, M is a hydrogen atom or 1 The above-mentioned emulsion composition for a heat storage material is a compound represented by the following formula: metal atom, ammonia, organic amine.

（但し式中、Ｒ²及びＲ³は各々独立して水素原子もしくは炭素数７〜１２の飽和又は不飽和脂肪酸残基を示すがＲ^２、Ｒ³が共に水素原子であることはない。又、ｍ及びｎは１以上の整数でありｍ＋ｎは２〜４０の整数を示す。）で表される化合物である上記蓄熱材用エマルション組成物がある。 In another preferred embodiment of the present invention, the (C) polyoxyethylene glycerol borate fatty acid ester is represented by the following general formula (C):

(In the formula, R ² and R ³ each independently represent a hydrogen atom or a saturated or unsaturated fatty acid residue having 7 to 12 carbon atoms, but R ² and R ³ are not both hydrogen atoms. , M and n are integers of 1 or more, and m + n represents an integer of 2 to 40.) There is the above-mentioned emulsion composition for a heat storage material.

Thus, by using a specific styrene / maleic anhydride copolymer salt, polyoxyalkylene alkyl ether phosphate and polyoxyethylene glycerol borate fatty acid ester according to the present invention in a certain blending ratio, an emulsion for a heat storage material Excellent emulsifying performance is exhibited when producing the composition. That is, the emulsion has a low viscosity and is excellent in long-term emulsion stability and heat storage efficiency. The use of the styrene / maleic anhydride copolymer salt, polyoxyalkylene alkyl ether phosphate, and polyoxyethylene glycerol borate fatty acid ester according to the present invention alone is not effective, and the composition limited in the present invention If it is out of proportion, the performance will be significantly reduced.
The reason why the emulsifier composition of the present invention exhibits excellent performance is not yet clear, but it is relatively large with respect to n-paraffin and has a benzene nucleus when forming an emulsion. Styrene groups and relatively small polyoxyalkylene groups are effectively arranged on the surface of the emulsified droplets, while water has a complex hydrophilic site such as a salt of styrene / maleic anhydride copolymer. This is considered to be the effect of acting on

Hereinafter, the present invention will be described in detail.
The salt of the styrene / maleic anhydride copolymer according to the present invention can be easily obtained by a known production method. For example, commercially available SMA (Styrene Maleic Anhydride) resins have an average acid value of 100 to 800, and there are ester types modified with alcohol and unmodified raw resin. Alternatively, it can be obtained by complete neutralization. Among these, it is preferable to use a raw material resin having an average acid value of 265 to 495 in terms of quality and performance. Examples of alkalis used for neutralization include monovalent alkali metal hydroxides such as caustic soda and caustic potash, alkanolamines such as monoethanolamine, diethanolamine and triethanolamine, and organic substances such as morpholine, cyclohexylamine and monopropanolamine. Although amines can be mentioned, caustic potash or morpholine is preferable in terms of effects.

  The polyoxyalkylene alkyl ether phosphate represented by the general formula (B) according to the present invention can be obtained by a known production method. For example, octyl alcohol, 2-ethylhexyl alcohol, decyl alcohol, dodecyl alcohol (lauryl alcohol), tridecyl alcohol, tetradecyl alcohol (myristyl alcohol), pentadecyl alcohol, hexadecyl alcohol (palmityl alcohol), octadecyl alcohol (stearyl alcohol) Phosphorylation of higher alcohols such as octadecenyl alcohol (oleyl alcohol) or alkylphenols such as phenol, nonylphenol, dodecylphenol, dinonylphenol using anhydrous phosphoric acid, or ethylene oxide and propylene oxide by known methods After addition of alkylene oxide, etc., phosphorylation using anhydrous phosphoric acid, followed by sodium hydroxide, hydroxide Monovalent alkali metal hydroxides, monoethanolamine, such as helium, diethanolamine, alkanolamines such as triethanolamine, morpholine, cyclohexylamine, can be obtained by neutralization with organic amines such as mono-propanolamine.

The quantitative relationship in the synthesis of each compound described above is as follows: anhydrous alcohol or higher alcohol or alkylphenol, or 2 to 3 mol of a compound obtained by adding 0 to 30 mol of ethylene oxide and / or ethylene oxide and propylene oxide thereto. It is preferable that polyoxyalkylene alkyl ether phosphoric acid reacted with 1 mol of phosphoric acid is further reacted with the alkali to form a neutralized salt.
Among these neutralized salts, 1 mol of phosphoric anhydride was reacted with 2.7 mol of a compound obtained by adding 3 to 10 mol of ethylene oxide and 0 to 5 mol of propylene oxide to 1 mol of oleyl alcohol or tridecyl alcohol in terms of effect. Polyoxyalkylene alkyl ether phosphates that are subsequently neutralized with monoethanolamine or morpholine are most preferred.

The polyoxyethylene glycerol borate fatty acid ester represented by the general formula (C) according to the present invention is obtained by reacting boric acid and glycerin to obtain glycerol borate, adding ethylene oxide, and further esterifying with fatty acid. It can be obtained by a known production method that reacts.
R ² and R ³ in the general formula (C) are each independently a hydrogen atom or a saturated or unsaturated fatty acid residue having 7 to 12 carbon atoms (however, R ² and R ³ are not both hydrogen atoms). In other words, specific examples of fatty acids include cabric acid, lauric acid, myristic acid, oleic acid, linoleic acid, palmitic acid, tall oil fatty acid, erucic acid, castor Examples include oil fatty acids, but oleic acid or linoleic acid is preferable in terms of effects. R ² and R ³ may be the same as or different from each other, and may be branched or linear.

M + n in the general formula (C) representing the number of added moles of ethylene oxide is preferably an integer of 2 to 40 in terms of obtaining good emulsifying properties, but is most preferably 8 to 20 in terms of performance.

The emulsifier composition according to the present invention is a blended product of two or more kinds of compounds, and the blending ratio is (A) 40 to 70% by weight of a styrene / maleic anhydride copolymer salt, and (B) polyoxyalkylene. The ratio is 30-60% by weight of alkyl ether phosphate and 0-30% by weight of (C) polyoxyethylene glycerol roll fatty acid ester. More preferably, a mixture containing (A) 45 to 60% by weight, (B) 35 to 50% by weight, and (C) 5 to 20% by weight exhibits the most suitable synergistic effect.

As the n-paraffin according to the present invention, a known paraffin can be used, but it is preferable to use a linear paraffin having 10 to 20 carbon atoms in view of the effect. Since the n-paraffin heat storage material in the emulsion exists in a fine particle state (average particle size of 1 to 10 μm), a peak difference occurs between the freezing point and the melting point compared to the state before emulsification, that is, a supercooling phenomenon occurs. And reduce the heat storage efficiency. In order to eliminate this supercooling phenomenon, it is preferable to add a small amount of a nucleating agent.
In order to exhibit the function as a nucleating agent, it is necessary to have a melting point higher than that of n-paraffin, and petroleum waxes having a melting point 35 ° C. higher than the melting point of n-paraffin are preferable. Specific examples include petroleum waxes such as paraffin wax, microcrystalline wax, and betrolatam. Paraffin wax having a melting point of 55 to 66 ° C. is preferable in terms of performance.

The use amount of the emulsifier composition of the present invention is 0.2 to 20.0 parts by weight with respect to 100 parts by weight of the total amount of n-paraffin and water. The range is parts by weight. If the addition is less than 0.2 parts by weight, the stability of the emulsion is lowered due to insufficient emulsifier, and the desired effect of the present invention is not exhibited. If the addition exceeds 20.0 parts by weight, the emulsifiability is not further improved. However, it is not preferable in terms of economy and quality. Moreover, you may use another additive together in the range which does not impair the effect of this invention.
The emulsification of the mixture of n-paraffin and water is performed by adding n-paraffin in which the emulsifier is dissolved in a container filled with water little by little with stirring. Further, a homomixer, a dispar mill, a high-pressure emulsifier, etc. If a commonly used emulsifier is used, a finer and more stable emulsion can be obtained.
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to a following example, unless the meaning is exceeded.

Compound production example 1
<Preparation of salt (A-1 to 4) of styrene / maleic anhydride copolymer according to the present invention>
A reaction vessel was charged with 2000 g of SMA2000A (manufactured by Sartomer, average acid value 355), 700 g of potassium hydroxide and 3500 g of water, heated to 100-105 ° C., stirred for 30 minutes, cooled to 30 ° C., cooled to 30 ° C., styrene -6150g of maleic anhydride copolymer potassium salt 40% aqueous solution (A-1) was obtained.
Compounds A-2, A-3, and A-4 shown in Table 1 were synthesized in the same manner as Compound A-1.

Compound production example 2
<Synthesis of Polyoxyalkylene Alkyl Ether Phosphate (B-1 to 6) According to the Present Invention>
Synthesis of B-1 compound: 270 g of oleyl alcohol and 0.5 g of caustic potash as a catalyst were added to an autoclave, 264 g of ethylene oxide was reacted at 170 to 180 ° C. over 3 hours, and then 57 g of phosphoric anhydride was added to 35 to 55 After addition at 0 ° C., the mixture was reacted at 100 ° C. for 3 hours.
Thereafter, the mixture was cooled to 30 ° C., and 45 g of monoethanolamine was added in small portions to partially neutralize, and the compound according to the present invention having a pale yellow viscous oil having a pH of 5.1, 630 g of polyoxyethylene oleyl ether phosphate monoethanolamine salt (B-1) Got.
Compounds B-2 and B-5 shown in Table 1 were synthesized in the same manner as Compound B-1.
Synthesis of B-3 compound: 280 g of oleyl alcohol and 0.7 g of caustic potash as a catalyst were added to an autoclave, and a mixture of 176 g of ethylene oxide and 116 g of propylene oxide was randomly reacted at 160 to 170 ° C. over 3 hours, and then After adding 57 g of phosphoric anhydride at 35 to 55 ° C., the mixture was reacted at 100 ° C. for 3 hours.
Thereafter, the mixture was cooled to 30 ° C. and 35 g of morpholine was added in small portions to partially neutralize to obtain 650 g of a light yellow viscous oily polyoxyethylene polyoxypropylene oleyl ether phosphate morpholine salt (B-3) having a pH of 5.2.
Compounds B-4 and B-6 shown in Table 1 were synthesized in the same manner as Compound B-3.

Compound production example 3
<Method for producing polyoxyethylene glycol borate fatty acid ester (C-1 to 4) according to the present invention>
A reaction vessel was charged with 62 g (1.0 mol) of boric acid and 184 g (2.0 mol) of glycerin, reacted at 230 ° C. for 4 hours, cooled to 120 ° C., 1 g of BF ₃ ethyl ether was added as a catalyst, and 1322 g of ethylene oxide. (30 mol: corresponding to a + b in the general formula (C)) was reacted for 3 hours.
Next, 282 g (1.0 mol) of oleic acid was added, the temperature was raised to 230 ° C., and the esterification reaction was carried out for 6 hours to obtain 1800 g of polyoxyethylene glycol borate monooleate (C-1) according to the present invention.
Compounds C-2, C-3, and C-4 shown in Table 1 were synthesized in the same manner as Compound C-1.

Compound Example <Production Method of Mixture 1>
In a mixing vessel, 50 parts by weight of potassium salt (compound A-1) of styrene / maleic anhydride copolymer (average acid value 355) and polyoxyethylene (4 mol) oleyl ether phosphate monoethanolamine salt (compound B-1) 30 parts by weight and 20 parts by weight of polyoxyethylene (30 mol) glycerol borate monooleate (Compound C-1) were charged and mixed at 30 to 40 ° C. for 30 minutes to obtain a mixture 1.
Moreover, the mixtures 2-13 of this invention and the comparative mixtures 1-6 were obtained by the same method. Table 2 summarizes the blend compositions of Mixtures 1-13 and Comparative Mixtures 1-6.

<Preparation of emulsion 1>
540 parts by weight of water is added to a 2 L emulsification container and heated to 60 ° C. In another 1 L container, 230 parts by weight of n-pentadecane (C ₁₅ ) and n-hexadecane (C ₁₆ ) and paraffin wax 125 ° F. 30 parts by weight Then, 20 parts by weight of an emulsifier composition (mixture 1 of the present invention) is added and mixed and heated to 80 ° C. This was gradually added to water with emulsification while emulsifying, and then emulsified, and then stirred at 7000 rpm for 5 minutes with a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) to obtain a crude emulsion 1.
Subsequently, using a high-pressure emulsifier (manufactured by Nippon Seiki Co., Ltd.) at the same temperature for 1 pass emulsification at a pressure of 300 kg / cm ² , the emulsion was cooled to 20 to 30 ° C. to obtain Emulsion 1. In the same manner, the emulsions 2 to 9 and 13 of the present invention (each using the mixtures 2 to 9 and 13 of the present invention shown in Table 2) and the comparative emulsions 1 to 3 and 5 (each shown in Table 2). Comparative mixtures 1 to 3 and 5) were obtained.

<Preparation of emulsion 2>
Add 300 parts by weight of water to a 2 L emulsification container and heat to 60 ° C. In another 1 L container, 400 parts by weight of n-pentadecane, 300 parts by weight of n-hexadecane and 15 parts by weight of an emulsifier composition (mixture 10 of the present invention) Are mixed and heated to 80 ° C. The mixture was gradually added to water while emulsifying and emulsified, and then stirred at 7000 rpm for 5 minutes with a TK homomixer (manufactured by Tokushu Kika Co., Ltd.), and then cooled to 20-30 ° C. to obtain an emulsion 10.
Emulsions 11 and 12 of the present invention (using the inventive mixtures 11 and 12 shown in Table 2, respectively) and comparative emulsions 4 and 6 (using the comparative mixtures 4 and 6 shown in Table 2 respectively) are obtained in the same manner. It was.
Table 3 summarizes the formulations of Examples 1 to 13 and Comparative Examples 1 to 6 for producing the emulsion.

<Evaluation of emulsion>
Using the emulsifier composition adjusted with the formulation shown in Table 2, an emulsion for a heat storage material based on the formulation of Table 3 was prepared. These emulsions were measured for (1) differential scanning calorimetry (DSC), (2) temperature cycle test, (3) viscosity, (4) flash point, and the like. The evaluation results are shown in Table 4.
Test Method (1) DSC (Thermal Analyzer DSC6200 manufactured by Seiko Instruments Inc.)
Temperature control (electric cooler) 20 → 0 → 20 (0 ° C 15 minutes hold, cooling and heating rate 1 ° C / min)
Heat storage amount (mj / mg) = Heat of fusion (2) Temperature cycle test 4L of emulsion is added to a 5L glass bottle and immersed in a low-temperature water bath, and the flow rate of the magnet pump (manufactured by Sansei Electric Co., Ltd.) is 8L / min. (120 cycles / Hr), the temperature was 10 ° C. (12 hours in the day) and 25 ° C. (12 hours in the night) repeatedly circulating for 30 days, and the emulsion stability, viscosity, and DSC were measured after 10 and 30 days. did.
(3) Viscosity BM viscometer 5 ° C
In the examples, the measurement was performed with rotor No. 1 and a rotational speed of 60 rpm. Moreover, the comparative example used rotor No. 2 and measured it at the rotation speed of 12 rpm.

Test results Nos. 1 to 13 in Table 4 are the results of testing emulsions in Examples of the present invention, and Comparative Examples Nos. 1 to 6 are results of testing emulsions other than the present invention.
The heat storage material emulsion composition of the present invention does not cause phase separation even in a cycle test as shown in Table 4, and can be used stably over a long period of time. Furthermore, since it has low viscosity and sufficient fluidity, it can be applied to various air conditioners and the like. Moreover, the test result in DSC measurement is also good, and shows about twice the heat storage efficiency as compared with the emulsion using the comparative compound, and the compound most used in the surfactant (emulsifier) already disclosed in the art. It is possible to provide a heat storage material that is far superior in comparison.

By using the emulsifier composition of the present invention, a low amount of emulsifier (surfactant) used, low viscosity, excellent emulsion stability, no supercooling problem, and high heat storage efficiency emulsion composition are provided. can do. In particular, it is easy to transport by piping and is optimal for use as a heat storage material used in heat transfer systems.

Claims (5)

10-70 parts by weight of n-paraffin, 90-30 parts by weight of water (however, the total of n-paraffin and water is 100 parts by weight), and as an emulsifier, (A) salt of styrene / maleic anhydride copolymer 40- 70% by weight, (B) 30% to 60% by weight of a compound represented by the following general formula (B), and (C) a polyoxyethylene glycerol borate fatty acid ester in a proportion of 0 to 30% by weight. An emulsion composition for a heat storage material, containing 0.2 to 20.0 parts by weight with respect to 100 parts by weight of water and water.

(In the formula , R ¹ represents a linear or branched alkyl group having 6 to 18 carbon atoms or an alkenyl group or an alkylphenyl group having an alkyl group having 8 to 18 carbon atoms, and (AO) x represents that A is ethylene. A (poly) alkylene oxide group comprising a group and / or a propylene group, x is an integer of 0 to 30, y is 1 or 2, and z is an integer satisfying a relationship of y + z = 3, M is a hydrogen atom or 1 Represents a valent metal atom, ammonium, or organic ammonium.) The salt of the (A) styrene / maleic anhydride copolymer is made from a raw material resin having an average acid value of 265 to 495 from ammonia, an organic amine, a monovalent alkali metal hydroxide, and a monovalent alkali metal salt. The emulsion composition for a heat storage material according to claim 1, which is a salt partially or completely neutralized by one or more selected. The (C) polyoxyethylene glycerol borate fatty acid ester is represented by the following general formula (C):

(In the formula, R ² and R ³ each independently represent a hydrogen atom or a saturated or unsaturated fatty acid residue having 7 to 12 carbon atoms, but R ² and R ³ are not both hydrogen atoms. Moreover, m and n are integers greater than or equal to 1, m + n shows the integer of 2-40.) The emulsion composition for heat storage materials of Claim 1 or 2 . The compound represented by the general formula (C) is obtained by reacting boric acid with glycerin to obtain glycerol borate, adding ethylene oxide, and further esterifying with fatty acid. It is a late fatty acid ester, The emulsion composition for heat storage materials of any one of Claims 1-3 . Emulsification is carried out by adding 1.0 to 10.0 parts by weight of petroleum wax having a melting point 35 ° C. or more higher than that of n-paraffin used in the present invention as a nucleating agent to 100 parts by weight of n-paraffin. The emulsion composition for heat storage materials according to any one of claims 1 to 4 .