JP2011062693A - Method for producing adsorbing material having heat accumulation function, adsorbing material having heat accumulation function and canister - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adsorbing material having a heat accumulation function, in which a heat storage material including a heat storage capsule and an adsorbing material are mixed, and to provide a technique for allowing the heat storage capsule to be hardly broken by increasing the strength thereof and ensuring excellent adsorption-desorption performance so that the heat accumulation performance is not deteriorated even under such a condition that moisture exists and even under such a condition that an organic solvent exists. <P>SOLUTION: A method for producing the adsorbing material 10 having the heat accumulation function, in which the heat storage material 4 including the heat storage capsule 3, that is obtained by encapsulating a phase change substance 1 for absorbing/radiating latent heat according to a temperature change in an outer shell, and the adsorbing material 5 are mixed, comprises the steps of: drying a dispersion liquid 3a including the heat storage capsule 3 to obtain powdery heat storage capsule 3b; and performing post-heat treatment for reheating the powdery heat storage capsule 3b within 110-140°C in order to again advance a polymerization reaction of a polymer compound 2 constituting the outer shell of the powdery heat storage capsule 3b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention has a heat storage function comprising a heat storage material including a heat storage capsule formed by encapsulating a phase change material that absorbs and releases latent heat in response to a temperature change, and an adsorbent. The present invention relates to an adsorbent manufacturing method, an adsorbent with a heat storage function manufactured by the manufacturing method, and a canister filled with the adsorbent with a heat storage function.

Production of an adsorbent with a heat accumulating function by mixing an adsorbent with a heat accumulator comprising a heat accumulator encapsulating a phase change material that absorbs and releases latent heat in response to temperature changes. The method is described in Patent Document 1, for example.
According to the adsorbent with a heat storage function, the temperature increase and decrease due to the heat of adsorption and desorption of the adsorbent can be prevented by the heat storage function of the heat storage material, and the adsorption / desorption performance of the adsorbent can be prevented from being lowered.

  That is, in general, the adsorption performance of the adsorbent decreases as the temperature of the adsorbent increases, and the desorption performance of the adsorbent decreases as the temperature of the adsorbent decreases. Therefore, when the temperature of the adsorbent rises due to the heat of adsorption generated when gas or the like is adsorbed on the adsorbent, the adsorption performance is reduced. On the other hand, when gas or the like is desorbed from the adsorbent, heat absorption due to desorption occurs, and when the temperature of the adsorbent decreases, the desorption performance is reduced. Such a decrease in adsorption / desorption performance is due to the temperature change of the adsorbent due to heat of adsorption / desorption. Therefore, a heat storage material is enclosed in a shell that contains a phase change substance that absorbs and releases latent heat according to the temperature change. The heat storage capsule (micro capsule, the same in the following) is configured to absorb or release latent heat when the phase change material undergoes a phase change, minimizing the temperature change of the adsorbent. Therefore, it is possible to obtain higher adsorption / desorption performance than those without a heat storage material.

  Conventionally, the above heat storage capsule is generally obtained by encapsulating in a medium of about 70 ° C. to 80 ° C., and then drying and solidifying the medium. Such solidified heat storage capsules are easy to handle and easy to use, and are used in a wide range of applications.

JP 2001-145832 A

  However, generally, when encapsulation is performed in a medium at 70 ° C. to 80 ° C., polymerization of a polymer compound (for example, melamine resin) constituting the outer shell of the heat storage capsule proceeds to some extent, but the degree of polymerization is relatively high. It is low and there are a large number of unreacted groups of the polymer compound, and it cannot be said that the heat storage capsule has sufficient strength depending on the application. When using such a heat storage capsule in the water slurry, there was almost no need to consider the possibility of destruction of the heat storage capsule, but when trying to use the heat storage capsule as a heat storage capsule solidified by drying it When the solidified heat storage capsule is mixed with an adsorbent with relatively high strength, etc., the heat storage capsule may be destroyed, and the heat storage performance is reduced due to the destruction of the heat storage capsule. Performance may be reduced.

In addition, when the adsorbent with a heat storage function in which the solidified heat storage capsule and the adsorbent are mixed is filled in a canister case, for example, gasoline adsorbed by the adsorbent in the case The vaporized fuel (organic solvent) may destroy or permeate the outer shell of the heat storage capsule and leak the phase change material enclosed in the outer shell to the outside.
Here, the canister is generally a surplus when the vehicle is stopped in order to prevent the vaporized fuel (gasoline etc.) supplied to the internal combustion engine of the vehicle etc. from being released to the outside (in the atmosphere etc.). The vaporized fuel is adsorbed by the adsorbent in the case, and the air is introduced into the case as a purge gas during traveling, and the adsorbed vaporized fuel is desorbed and supplied again to the internal combustion engine or the like.
Further, when the adsorbent with a heat storage function in which the solidified heat storage capsule and the adsorbent are mixed, for example, in the case of the canister, moisture or moisture present in the case is removed. There is a possibility that the outer shell of the heat storage capsule is deteriorated, the outer shell is destroyed, and the phase change material enclosed in the outer shell is leaked to the outside.
Such leakage of the phase change material to the outside may reduce the heat storage function and may cause a decrease in adsorption / desorption performance.

  The present invention has been made in view of the above-described problems, and its purpose is to provide a heat storage function-adsorbing material in which a heat storage material including an heat storage capsule and an adsorbent are mixed, and the strength of the heat storage capsule is reduced. Therefore, the present invention is to provide a technique capable of ensuring good adsorption / desorption performance without deteriorating heat storage performance even under conditions where moisture and moisture are present and conditions where an organic solvent is present.

In order to achieve the above object, a method for producing an adsorbent with a heat storage function according to the present invention includes a heat storage capsule in which a phase change material that absorbs and releases latent heat according to a temperature change is enclosed in an outer shell. A method for producing an adsorbent with a heat storage function formed by mixing an adsorbent and a heat storage material, wherein the first characteristic means is to dry the dispersion containing the heat storage capsule to obtain a powdered heat storage After completing the capsule,
As a reaction re-promoting treatment for re-promoting the polymerization reaction of the polymer compound that forms the outer shell of the powder heat storage capsule, the powder heat storage capsule is reheated at a heating temperature in the range of 110 ° C. to 140 ° C. It is in the point which performs a post-heating process.

  According to the first feature means, the adsorbent is mixed with a heat storage material configured to include a heat storage capsule formed by enclosing a phase change material that absorbs and releases latent heat in response to a temperature change. When the adsorbent with a heat storage function is manufactured, a reaction re-promoting process for re-promoting the polymerization reaction is performed on the polymer compound constituting the outer shell of the heat storage capsule.

Thereby, the polymerization reaction of the polymer compound constituting the outer shell of the heat storage capsule is re-promoted, the degree of polymerization can be increased, and the strength of the outer shell (heat storage capsule) can be increased.
That is, the outer shell of the heat storage capsule is formed by forming a film of a polymer compound around the phase change material, and the degree of polymerization of the film is increased by the polymerization reaction. In some cases, pores remain, and the presence of the pores may not provide sufficient film strength. That is, the strength of the outer shell is determined according to the degree of polymerization of the membrane, but the strength of the heat storage capsule can be increased by increasing the degree of polymerization (reducing the pores).
Such a heat storage capsule with increased strength is difficult to break even when mixed with a relatively hard adsorbent, and the heat storage performance is unlikely to deteriorate, thus preventing a decrease in the adsorption / desorption performance of the adsorbent with the heat storage function. be able to.
In addition, since the pores existing in the membrane are substantially reduced, the outer shell of the heat storage capsule is destroyed or permeated under the condition where the organic solvent is present, and the phase change material enclosed in the outer shell is externally exposed. In addition, the outer shell of the heat storage capsule is deteriorated and destroyed even under conditions where moisture, moisture, etc. are present, and the phase change material enclosed in the outer shell is prevented from leaking to the outside. it can.

Furthermore, after drying the dispersion liquid containing the heat storage capsule and completing the powdered heat storage capsule, the powdered heat storage capsule after the encapsulation treatment is post-heat treated, so at the stage where the encapsulation process is completed, Even when the degree of polymerization of the completed heat storage capsule is low, the degree of polymerization of the polymer compound constituting the outer shell can be further increased by post-heating the heat storage capsule, and the strength of the heat storage capsule can be increased. Can be raised.
That is, when a solid heat storage capsule is completed, if the heat storage capsule is used as it is, the strength becomes insufficient, and even when the heat storage performance is deteriorated due to destruction of the heat storage capsule, the heat storage capsule is post-heat treated. By doing so, it is possible to further increase the strength of the heat storage capsule, to prevent a decrease in heat storage performance due to the destruction of the heat storage capsule, and to prevent a decrease in adsorption / desorption performance of the adsorbent with a heat storage function .
In this case, in particular, as shown in FIG. 6, when a solid (powder) thermal storage capsule (the outer shell is a melamine resin) is post-heat treated, the thermal storage capsule is compared with a case where no post-heating treatment is performed. The weight reduction rate of will decrease. That is, by performing the post-heating treatment, the degree of polymerization of the polymer compound (melamine resin, which is a thermosetting resin in FIG. 6) constituting the outer shell of the heat storage capsule is increased, and the phase change enclosed in the outer shell is increased. The substance does not leak to the outside, and the weight reduction of the heat storage capsule hardly occurs. Therefore, the heat storage performance can be prevented from being lowered, and the adsorption / desorption performance can be prevented from being lowered.
In addition, since the strength of the heat storage capsule is increased, the number of minute pores remaining when the degree of polymerization is low is reduced, and the outer shell of the heat storage capsule is destroyed or permeated in the presence of an organic solvent, The phase change material enclosed in the outer shell can be more effectively prevented from leaking to the outside, and the outer shell of the heat storage capsule is deteriorated and destroyed even under conditions where moisture, moisture, etc. exist, It is possible to more effectively prevent the phase change material enclosed in the liquid from leaking outside.

  Furthermore, since the heating temperature in the reheating treatment can be set within a range of 110 ° C. or more and 140 ° C. or less, the polymer compound is sufficiently destroyed while the polymer compound is not destroyed by heat. It can reheat and can prevent the heat storage performance from deteriorating. Here, the heating temperature is set to 110 ° C. or higher in order to sufficiently advance the further polymerization reaction, while the heating temperature is set to 140 ° C. or lower in order to thermally decompose the polymer compound constituting the outer shell of the heat storage capsule. It is for suppressing.

  The 2nd characteristic means of the manufacturing method of the adsorbent with a heat storage function which concerns on this invention exists in the point which makes the said heat storage material the granular heat storage material which shape | molded the said powder-like heat storage capsule into the particle shape with the binder.

According to the said 2nd characteristic means, a some heat storage capsule can be shape | molded to a granule with a binder, and a heat storage material can be comprised as a granular heat storage material.
This makes it possible to reduce the breakage when mixing with a relatively hard adsorbent by forming a plurality of heat storage capsules in a granular form with a binder before mixing with the adsorbent, preventing deterioration of the heat storage performance Thus, it is possible to manufacture an adsorbent with a heat storage function that can prevent a decrease in adsorption / desorption performance.

  The third characteristic means of the method for producing an adsorbent with a heat storage function according to the present invention is the adsorption with an integrally formed heat storage function in which the adsorbent with the heat storage function is integrally formed by mixing the heat storage material and the adsorbent together with a binder. It is in the point to use as a material.

According to the said 3rd characteristic means, the heat storage material and the adsorbent are mixed with the binder, and the integrally formed heat storage function-equipped adsorbent can be obtained.
As a result, when the heat storage material and the adsorbent are simply mixed, the heat storage material and the adsorbent are separated and classified according to usage conditions, etc., and the adsorption performance due to the inability to properly store the heat of adsorption and desorption from the adsorbent. Can be prevented, and an integrally formed heat storage function-equipped adsorbent capable of maintaining high adsorption / desorption performance can be obtained.

  The first characteristic configuration of the adsorbent with a heat storage function according to the present invention for achieving the above object is the one with a heat storage function manufactured by the method for manufacturing an adsorbent with a heat storage function according to any one of the first to third characteristic means. It is an adsorbent.

  According to the first characteristic configuration, it is possible to obtain an adsorbent with a heat storage function in which an adsorbent is mixed with a heat storage material in which the strength of the heat storage capsule is improved, and when the adsorbent adsorbs / desorbs gas or the like. Since the heat of adsorption / desorption can be stored appropriately, a decrease in adsorption performance can be appropriately prevented.

  To achieve the above object, the second characteristic configuration of the canister according to the present invention is an adsorbent with a heat storage function manufactured by the method for manufacturing an adsorbent with a heat storage function according to any one of the first to third characteristic means. The point is that it is filled in the case.

  According to the second characteristic configuration, by filling the adsorbent with the heat storage function in which the strength of the heat storage capsule is improved in the case of the canister, the transpiration fuel such as gasoline adsorbed by the adsorbent in the case Breaks or permeates the outer shell of the heat storage capsule and prevents the phase change material enclosed in the outer shell from leaking to the outside, and moisture or moisture present in the case deteriorates the outer shell of the heat storage capsule. Thus, the outer shell can be destroyed and the phase change material sealed in the outer shell can be prevented from leaking to the outside.

  As a result, the adsorption / desorption performance can be maintained at a high level to improve the throughput of the vaporized fuel in the canister, and the possibility that a phase change material or a polymer compound enters the internal combustion engine to cause a malfunction can be reduced. .

Schematic showing the process of manufacturing an adsorbent with a heat storage function in the first embodiment The figure which shows the outline of the post-heating process in this method The figure which shows the outline of post-heating processing different from this method The figure which shows the outline of the acid treatment in a reference example The figure which shows the outline of the acid treatment in a reference example Graph showing the relationship between post-heating temperature and weight loss rate Graph showing the relationship between E10 gasoline immersion time and the amount of heat that can be stored

An embodiment of a method for producing an adsorbent 10 with a heat storage function according to the present invention (hereinafter abbreviated as the present method) will be described with reference to the drawings.
[First Embodiment]
As shown in FIG. 1, this method includes a heat storage material 4 including a heat storage capsule 3 formed by enclosing a phase change material 1 that absorbs and releases latent heat in response to a temperature change in an outer shell, and an adsorption This is a method for producing the adsorbent 10 with a heat storage function by mixing the material 5, and, as shown in FIGS. 2 to 5, the polymer compound 2 constituting the outer shell of the heat storage capsule 3 with respect to the heat storage capsule 3. A reaction re-promoting treatment for re-promoting the polymerization reaction is performed.

  FIG. 1 is a schematic view showing a process of manufacturing a heat storage capsule 3 to produce a heat storage material 4 and mixing with the adsorbent 5 to manufacture an adsorbent 10 with a heat storage function. There are a stage, a manufacturing stage of the granular heat storage material 4a, and a manufacturing stage of the adsorbent 10 with a heat storage function.

[Heat storage capsule 3]
As shown in FIG. 1, the heat storage capsule 3 is configured by a microcapsule in which a phase change material 1 that absorbs and releases latent heat according to a temperature change is enclosed in an outer shell.
The phase change material 1 is not particularly limited as long as it is a compound that absorbs and releases latent heat in accordance with the phase change, but the temperature at which the phase change occurs corresponding to the use of the adsorbent 10 with a heat storage function (for example, the melting point). The compound can be selected according to the freezing point and the like. For example, the compound is composed of an organic compound and an inorganic compound having a melting point of about −150 ° C. to 100 ° C. and preferably for the canister 30 of about 0 ° C. to 50 ° C. Specific examples include straight-chain aliphatic hydrocarbons such as tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, heikosan, docosan, natural wax, petroleum wax, LiNO ₃ .3H ₂ O, Na ₂ SO _4.・ Hydrates of inorganic compounds such as 10H ₂ O and Na ₂ HPO ₄ · 12H ₂ O, fatty acids such as capric acid and lauric acid, higher alcohols having 12 to 15 carbon atoms, ester compounds such as methyl palmitate, etc. Can be used. In addition, as a phase change, phase changes, such as between solid-liquid, can be illustrated.
The phase change material 1 may be used in combination of two or more compounds selected from the above. When two or more kinds of phase change materials 1 are used in combination, the difference in temperature causing the phase change of each phase change material 1 is about 0 ° C. to 100 ° C., preferably 0 ° C. to 15 ° C. for canisters. A combination is preferred.
Further, in order to prevent the supercooling phenomenon of the phase change material 1, a compound having a melting point higher than that of the phase change material 1 may be added as necessary.

  And these can be used as the heat storage capsule 3 by using microcapsules as a core material by a known method such as a coacervation method or an in-situ method (interface reaction method). For example, after the phase change material 1 is emulsified in a medium using an emulsifier such as a surfactant, and an initial condensate (prepolymer) corresponding to a desired polymer compound 2 (resin etc.) described later is added thereto The dispersion (slurry) 3a of the heat storage capsule 3 having the outer shell (resin wall, etc.) and enclosing the phase change material 1 in the outer shell can be adjusted by heating to about 70 ° C. and proceeding the polymerization reaction. it can. For example, if this heat storage capsule dispersion liquid 3a is dried, a solid material of the heat storage capsule 3 (powdered heat storage capsule 3b) can be obtained.

As the outer shell of the heat storage capsule 3 (microcapsule), the known polymer compound 2 can be used without particular limitation. For example, formaldehyde-melamine resin, melamine resin, formaldehyde-urea resin, urea resin, urea-formaldehyde- Polyacrylic acid copolymer, polystyrene, polyvinyl acetate, polyacrylonitrile, polyethylene, polybutyl methacrylate, gelatin and the like can be used. Preferably, a thermosetting resin, particularly a melamine resin is used.
The weight ratio of the outer shell of the heat storage capsule 3 to the phase change material 1 (outer shell: phase change material 1) is not particularly limited, but is usually about 40:60 to 5:95, preferably about 30:70 to 10:90. is there.
The average particle diameter of the heat storage capsule 3 can be appropriately selected from the necessary heat storage amount and capsule strength, but it can prevent destruction of the heat storage capsule 3 while ensuring the desired heat storage performance. An average particle size of about 10 μm is preferred.

[Heat storage material 4 (granular heat storage material 4a)]
As shown in FIG. 1, the heat storage material 4 is configured to include the heat storage capsule 3 as long as it can be mixed with the adsorbent 5. In the case of the present embodiment, a powdered heat storage capsule 3 b is used. That is, the powdery heat storage capsule 3b can be obtained by drying the dispersion 3a containing the heat storage capsule 3, and the powdery heat storage capsule 3b is kneaded with the binder 6 and granulated by a known granulator. The heat storage material 4a can be obtained.
As the binder 6, a known binder (thermoplastic resin, thermosetting resin) can be used, and can be appropriately selected depending on the usage and conditions of the adsorbent 10 with a heat storage function. For example, methyl cellulose Cellulose such as carboxymethyl cellulose, phenol resin, polyvinyl alcohol, vinyl acetate, amide ester and the like can be used. In particular, when the adsorbent 10 with a heat storage function is used for the canister 30, solvent resistance (transpiration resistance) and water resistance are required, and therefore it is necessary to use a binder 6 that satisfies this requirement. For example, a thermosetting resin such as phenol, acrylic, isocyanate, melamine, urethane, amide ester, etc., in which the granular heat storage material 4 has a JIS hardness (JIS K 1474) of 90% or more. Is preferred.
The shape of the granular heat storage material 4a is not particularly limited, but can be formed into an arbitrary shape such as a pellet (cylindrical or spherical), a disk, a block, or a honeycomb. Further, the average particle diameter is not particularly limited, but can be generally selected from about 0.1 mm to 4 mm, preferably about 0.3 mm to 3.5 mm, more preferably about 0.5 mm to 2.5 mm. In addition, in the relationship with the adsorbent 10a with an integrally-molded heat storage function to be described later (the adsorbent obtained by mixing the heat storage material 4 and the adsorbent 5 together with the binder 6 and integrally molded), it is more than the average particle diameter of the granular heat storage material 4a. The average particle diameter of the integrally molded adsorbent with heat storage function 10a is molded larger.

[Adsorbent 5]
The adsorbent 5 can be a known adsorbent capable of adsorbing gas or the like, and in the case of the canister 30, a known adsorbent capable of adsorbing a vaporized fuel can be used. For example, activated carbon, zeolite, silica gel , Organometallic complexes (copper fumarate, copper terephthalate, copper cyclohexanedicarboxylate, etc.) or a mixture thereof can be used.
Examples of the gas that is adsorbed by the adsorbent 5 include methane, methane-based gas (natural gas, digestion gas, etc.), ethane, propane, dimethyl ether, CO ₂ , hydrogen sulfide, oxygen, nitrogen, NO _x , SO _x , CO, acetylene, ethylene, ammonia, methanol, ethanol, water, chloroform, aldehyde, etc. are exemplified, but when the adsorbent 5 is filled in the case 31 of the canister 30, a vaporized fuel, in particular, It becomes gasoline.
The adsorbent 5 may be obtained by crushing activated carbon or the like, or may be used as the granular adsorbent 5a by molding the crushed material into granules. About this shaping | molding, it knead | mixes with the binder 6 similarly to the case of the granular heat storage material 4a.

[Adsorbent with heat storage function 10 (Adsorbent with integral molding heat storage function 10a)]
Although the heat storage function-equipped adsorbent 10 is configured by mixing the heat storage material 4 and the adsorbent 5, the mixing method is not particularly limited. For example, the respective powders of the heat storage material 4 and the adsorbent 5 may be simply mixed, or the dispersion liquid 3a of the heat storage capsule 3 may be sprayed on the powder of the adsorbent 5, and the granular heat storage material 4a and the granular material It is only necessary to uniformly mix the adsorbent 5a. Furthermore, as shown in the manufacturing stage of the adsorbent 10 with a heat storage function of FIG. 1, after mixing the granular heat storage material 4a and the granular adsorbent 5a, they are integrated by a binder 6 to form an integrally formed adsorbent 10a with a heat storage function. Also good.
The integrally molded adsorbent with heat storage function 10a is configured by mixing the granular heat storage material 4a and the granular adsorbent 5a as described above and then integrated with the binder 6, but there is no particular limitation on the shape thereof. , Pellets (columnar, spherical), disks, blocks, honeycombs, etc. The average particle diameter is not particularly limited, but usually, when used for the canister 30, it is about 0.5 mm to 4 mm, preferably about 0.5 mm to 3.6 mm, more preferably about 1 mm to 3 mm.
The binder 6 is not particularly limited as in the case of the granular heat storage material 4a, and a known binder can be used, but particularly when used for the canister 30, the organic solvent resistance and water resistance are improved. It is preferable to use the binder 6 that is included.

[Reaction promotion process]
In the present application, a reaction re-promotion process is performed in the manufacturing stage of the heat storage capsule 3 shown in FIG. This process will be described below.
As the reaction re-promoting process, a reheating process that is a process for re-promoting the polymerization reaction of the polymer compound 2 is performed.

  As the reheating treatment, a post-heating treatment (FIG. 2) in the manufacturing stage of the heat storage capsule 3 can be exemplified, and this will be described below.

<Reaction promotion treatment I (post-heating treatment)>
As shown in FIG. 2, the post-heat treatment was performed after the heat storage capsule 3 was encapsulated, that is, the phase change material 1 was emulsified, the initial condensate was added, and dried to solidify the heat storage capsule 3. Later, the completed heat storage capsule 3 is reheated.
Thereby, the polymerization reaction of the unreacted groups of the polymer compound 2 in the completed solidified heat storage capsule 3 proceeds, a dense film is formed, the degree of polymerization is improved, and the heat storage capsule 3 having higher strength. Can be obtained.
Specifically, as shown in FIG. 2, the dispersion liquid 3a of the completed heat storage capsule 3 is dried to produce a powder heat storage capsule 3b, and the powder heat storage capsule 3b is post-heat treated. The heat storage capsule 3 having higher strength can be obtained.
As shown in FIG. 3, the powder heat storage capsule 3b may be used as a granular heat storage material 4a with a binder, and the heat storage capsule 3 contained in the granular heat storage material 4a may be post-heat treated, although not shown. Alternatively, the heat storage capsule 3 included in the adsorbent 10a with an integrated heat storage function in which the granular heat storage material 4a and the granular adsorbent 5a are integrated by the binder 6 may be post-heat treated.

  The reheating treatment (including post-heating treatment) is performed in the range of 110 ° C. to 140 ° C. More preferably, it is 110 degreeC or more and 130 degrees C or less. Here, the heating temperature is set to 110 ° C. or higher in order to sufficiently advance the further polymerization reaction, while the heating temperature is set to 140 ° C. or lower in order to thermally decompose the polymer compound constituting the outer shell of the heat storage capsule. It is for suppressing.

<Reaction promotion treatment II, III (acid treatment)>
The acid treatment may be any acid treatment that can improve water resistance by changing a hydrophilic group as described later. For example, in the production stage of the granular heat storage material 4a, for the granular heat storage material 4a, Examples include immersion in a solution containing an acid, spraying of a solution containing an acid, mixing of an acid when molding the granular heat storage material 4a or the adsorbent 10a with an integrally molded heat storage function.
That is, when the heat storage capsule 3 is encapsulated, the phase change material 1 is dissolved in a surfactant solution and emulsified, and then the polymerization reaction of the polymer compound 2 is performed. The surfactant remains in the outer shell of the heat storage capsule 3 (polymer compound 2). Since the remaining surfactant has a hydrophilic hydrophilic group, the outer shell of the heat storage capsule 3 easily binds to moisture, and the outer shell may be deteriorated by moisture. Therefore, it is possible to improve the water resistance by changing the hydrophilic group of the surfactant by acid treatment to prevent binding with moisture.
Thereby, even if the surfactant used in the encapsulation process of the thermal storage capsule 3 remains in the outer shell of the thermal storage capsule 3, the thermal storage capsule 3 can be treated with an acid to treat the surfactant. The hydrophilicity can be reduced and the water resistance of the heat storage capsule 3 can be improved.

Such an acid treatment can be performed on the completed solid heat storage capsule 3 after the encapsulation process of the heat storage capsule 3.
For example, as shown in FIG. 4, the acid treatment can be performed by adding acid when the finished powdery heat storage capsule 3 b is molded together with the binder 6 to form the granular heat storage material 4 a.
Thereby, the hydrophilic group of the surfactant remaining in the outer shell of the heat storage capsule 3 can be reduced, and the granular heat storage material 4a with improved water resistance can be obtained.

In addition, as shown in FIG. 5, the acid treatment is performed by immersing the granular heat storage material 4a in the acid aqueous solution after forming the powdered heat storage capsule 3b with the binder 6 to form the granular heat storage material 4a. Can be done.
Thereby, the hydrophilic group of the surfactant remaining in the outer shell of the heat storage capsule 3 can be reduced, and the granular heat storage material 4a with improved water resistance can be obtained.

  The acid used in the acid treatment is not particularly limited as long as it is a water-soluble acid. For example, acetic acid, formic acid, propionic acid, oxalic acid, phthalic acid, citric acid, phosphoric acid and the like can be used.

Hereinafter, this method will be specifically described with reference to examples.
Example 1
6.5 g of 37% formaldehyde aqueous solution and 10 g of water were added to 5 g of melamine powder and the pH was adjusted to 8, followed by heating to about 70 ° C. to obtain a melamine-formaldehyde initial condensate aqueous solution. To 100 g of sodium salt aqueous solution of styrene maleic anhydride copolymer adjusted to pH 4.5, a mixed solution in which 58 g of hexadecane is dissolved as phase change material 1 is added with vigorous stirring, and the particle size becomes about 6 μm. Until the emulsification. The total amount of the melamine-formaldehyde initial condensate aqueous solution was added to the emulsified aqueous solution, and the mixture was stirred at 70 ° C. for 2 hours. Then, the pH was adjusted to 9 and encapsulation was performed. By this encapsulation process, a dispersion 3a of the heat storage capsule 3 in which hexadecane as the phase change material 1 was enclosed in the outer shell made of melamine resin was obtained. After completion of the reaction, the heat storage capsule 3 was spray-dried to obtain a powdered heat storage capsule 3b having a particle size of about 6 μm.

In the production stage (post-heating treatment) of the heat storage capsule shown in FIG. 2, the encapsulated powdery heat storage capsule 3b obtained is subjected to each predetermined temperature (from 80 ° C. to 130 ° C.) shown on the horizontal axis in FIG. ) For 3 hours as a post-heating treatment. Thereafter, the weight loss rate up to 200 ° C. was measured by thermal analysis. The weight reduction ratio is the weight reduction ratio ((M _i / M _O ) −1 of the weight M _i of the powdered heat storage capsule 3b after the thermal analysis with respect to the weight M _O of the powdered heat storage capsule 3b before the thermal analysis. ) (FIG. 6).
As a result, as shown in FIG. 6, the weight M _i of the powdered heat storage capsule 3b after the thermal analysis is reduced from the weight M _O before the thermal analysis by post-heating the powdered heat storage capsule 3b. It became clear that the polymerization reaction of the melamine resin (polymer compound 2) constituting the outer shell of the heat storage capsule 3 progressed, the degree of polymerization increased, and a dense film (outer shell) was generated.

(Comparative Example 1)
Moreover, as shown in FIG. 6, the result of performing a thermal analysis on the powdered heat storage capsule 3b not subjected to post-heating treatment using the powdered heat storage capsule 3b described in Example 1 is as shown in FIG. It was found that the weight M _i of the powdered heat storage capsule 3b after the thermal analysis was reduced by about 10% from the weight M _O before the thermal analysis.

Therefore, from the results of Example 1 and Comparative Example 1, the weight reduction rate after thermal analysis is smaller when the post-heating treatment is performed than when the post-heating treatment is not performed, and the strength of the heat storage capsule 3 is increased. Can be judged to have improved.
Further, as the temperature of the post-heat treatment rises, a dense outline is formed by polymerization of unreacted groups of the melamine resin, and the phase change material 1 enclosed in the outline is not leaked to the outside of the outline. remain in, be determined that the decrease of the weight M _i of powdered heat storage capsule 3b after thermal analysis is suppressed, with stronger shell are configured, determines that reduction of the heat storage performance is small it can.
In particular, as shown in FIG. 6, when the powdered heat storage capsule 3 b is post-heated at a temperature higher than 80 ° C., the weight reduction rate decreases, but preferably 110 ° C. or higher and 140 ° C. or lower, more preferably 110 ° C. When the post-heating treatment is performed at a temperature of not lower than 130 ° C. and not higher than 130 ° C., the weight reduction ratio may be reduced.

(Example 2)
As shown in FIG. 2, the encapsulated powdered heat storage capsule 3b produced in the same manner as in Example 1 was post-heated at 130 ° C. for 3 hours. Then, the powdered heat storage capsule 3b after the post-heating treatment is immersed in a mixed medium of 90% by mass of E10 gasoline and 10% by mass of ethanol at 40 ° C. for a predetermined time, taken out, washed with hexane, and 100%. It vacuum-dried at 0 degreeC and measured the calorie | heat amount which can be stored (FIG. 7).
As a result, as shown in FIG. 7, even when the immersion time in E10 gasoline elapses, the heat storage capsule 3 has a small decrease in the amount of heat that can be stored, and the heat storage performance does not substantially decrease. This is because by performing post-heating treatment, a dense film is formed by polymerization of unreacted groups of the melamine resin, the strength of the outer shell of the heat storage capsule 3 is improved, and the leakage of the phase change material 1 in the E10 gasoline atmosphere It can be determined that this is due to the result of the minimum suppression.

(Comparative Example 2)
The encapsulated powdery heat storage capsule 3b produced in the same manner as in Example 1 was subjected to a mixed medium of 90% by mass of E10 gasoline and 10% by mass of ethanol at 40 ° C. for a predetermined time without post-heating treatment. After immersion, the sample was taken out, washed with hexane, vacuum dried at 100 ° C., and the amount of heat that could be stored was measured (FIG. 7).
As a result, as shown in FIG. 7, as the immersion time in E10 gasoline elapses, the amount of heat that can be stored in the powdered heat storage capsule 3 b is considerably reduced.

  Therefore, as shown in FIG. 7, the heat storage capsule 3b in powder form has a large amount of heat that can be stored after immersion in E10 gasoline when it is post-heat treated at 130 ° C. for 3 hours and when it is not post-heat treated. Since the difference has arisen and the heat storage performance is maintained when the post-heating process is performed, it can be determined that the resistance to the E10 gasoline is improved by the post-heating process. Therefore, the heat storage capsule 3 that can maintain the adsorption / desorption performance for a long time can be obtained because the heat storage performance is not easily lowered even under the condition of being in contact with E10 gasoline for a long time.

(Reference Example 1)
As shown in FIG. 4, in the production stage of the granular heat storage material 4 a, the encapsulated powdered heat storage capsule 3 b manufactured in the same manner as in Example 1 was used as a 1.2 mass% acetic acid aqueous solution 22 and a binder 6. Mixing with amide ester and water (acid treatment), 2 mm diameter pellets (granular heat storage material 4a) were prepared. The pellet was dried and immersed in water at 80 ° C. for 72 hours, and then the cutting strength of the pellet was measured.
As a result, the cutting strength was 5N.

(Reference Example 2)
As shown in FIG. 5, in the production stage of the granular heat storage material 4a, the powdered heat storage capsule 3b after the encapsulation process manufactured in the same manner as in Example 1 is mixed with an amide ester and water as a binder 6, A 2 mm diameter pellet (granular heat storage material 4a) was prepared. The pellets were dried, then immersed in an acetic acid aqueous solution 22 having a pH of 3.3 at room temperature for 3 hours (acid treatment), taken out, and dried. The dried pellet was immersed in water at 80 ° C. for 72 hours, and then the cutting strength of the pellet was measured.
As a result, the cutting strength was 6N.

(Comparative Example 3)
The encapsulated powdered heat storage capsule 3b produced in the same manner as in Example 1 was mixed with amide ester and water as binder 6 without performing acid treatment as in Reference Examples 1 and 2, and the diameter was 2 mm. A plurality of pellets were prepared. The pellets were dried and immersed in water at 80 ° C. for 72 hours, and then the cutting strength of these pellets was measured.
As a result, the cutting strength was 1 to 1.5N.

  Therefore, the reference examples 1 and 2 in which the acid treatment was performed as described above were compared with the comparative example 3 in which the acid treatment was not performed, and the heat storage composed of the heat storage capsule 3 even when immersed in water for a long time. It can be judged that the strength (cutting strength) of the pellets of the material 4 is improved, and the water resistance is improved. Specifically, the powdered heat storage capsule 3b used in Reference Examples 1 and 2 (similar to the powdered heat storage capsule 3b manufactured in Example 1) has styrene maleic anhydride as a surfactant at the time of manufacture. After the heat storage capsule 3 is manufactured, the styrene maleic anhydride remains in the outer shell (polymer compound 2) of the heat storage capsule 3 in the form of sodium salt of maleic acid. [O-Na] present in the sodium salt is changed to [OH] by the above-mentioned acid treatment, thereby reducing the hydrophilicity of the outer shell of the heat storage capsule 3 and forming a powder heat storage capsule composed of the heat storage capsule 3 It is considered that the water resistance of 3b is improved.

[Another embodiment]
In the first embodiment, the use of the adsorbent with heat storage function 10 manufactured by the present method is not particularly limited, but the adsorbent with heat storage function 10 can also be used particularly for the canister 30.
Here, the canister 30 is generally used when the vehicle is stopped in order to prevent vaporized fuel (organic solvent, etc.) supplied to an internal combustion engine such as a vehicle from being released to the outside (in the atmosphere, etc.). Adsorbs excess vaporized fuel to the adsorbent 5 in the case 31, and introduces the atmosphere into the case 31 as a purge gas during running, etc., desorbs the vaporized fuel adsorbed, and supplies it again to the internal combustion engine or the like. Is.

In the canister 30, the adsorbent 10 with a heat storage function in which the solidified heat storage material 4 and the adsorbent 5 are mixed may be used by filling the case 31. In this case, the adsorbent 5 having relatively high strength is used. The solidified heat storage material 4 may be destroyed, and the heat storage performance may be reduced.
In addition, the adsorbent 10 with a heat storage function filled in the case 31 of the canister 30 is in contact with the vaporized fuel such as gasoline and is also in contact with moisture contained in the atmosphere. Property) and water resistance are required.

  Therefore, when the heat storage function adsorbent 10 constituted by the heat storage capsule 3 having high strength, high solvent resistance, and excellent water resistance described in the first embodiment is filled in the case 31 of the canister 30 and used, It is possible to obtain a canister 30 that can prevent a decrease in adsorption / desorption performance over a long period of time.

The canister 30 is provided with a flow passage through which a vaporized fuel such as gasoline circulates in a case 31, and an inlet into which the vaporized fuel flows in and an outlet through which the vaporized fuel flows out on a wall on one end side of the flow passage. And an air inflow port through which air flows in is provided on the wall on the other end side of the flow passage.
In such a canister 30, the vaporized fuel that has flowed from the fuel tank through the inlet is adsorbed by the adsorbent 10 with a heat storage function filled in the flow passage in the case 31 when the vehicle is stopped, The adsorbed / desorbed operation of the vaporized fuel is performed such that the adsorbed vaporized fuel is desorbed by the air flowing in from the air inlet, and the vaporized fuel is supplied from the outlet to the internal combustion engine and burned.

  The method for producing an adsorbent with a heat storage function according to the present invention is an adsorbent with a heat storage function in which an adsorbent and a heat storage material configured to include a heat storage capsule are mixed. The heat storage performance does not deteriorate even under conditions where moisture and moisture are present and conditions where an organic solvent is present, and can be effectively used as a technique that can ensure good adsorption / desorption performance.

1: Phase change material 2: Polymer compound (outer)
3: Heat storage capsule 3a: Dispersion liquid 3b: Powdered heat storage capsule 4: Heat storage material 4a: Granular heat storage material 5: Adsorbent material 6: Binder 10: Adsorbent material 10a with a heat storage function: Adsorbent material 30 with an integrated molding heat storage function 30: Canister 31: Case

Claims (5)

Production of an adsorbent with a heat accumulating function by mixing an adsorbent with a heat accumulator comprising a heat accumulator encapsulating a phase change material that absorbs and releases latent heat in response to temperature changes. A method,
After drying the dispersion containing the heat storage capsules to complete a powdered heat storage capsule,
As a reaction re-promoting treatment for re-promoting the polymerization reaction of the polymer compound that forms the outer shell of the powder heat storage capsule, the powder heat storage capsule is reheated at a heating temperature in the range of 110 ° C. to 140 ° C. A method for producing an adsorbent with a heat storage function that performs post-heating treatment.   The method for producing an adsorbent with a heat storage function according to claim 1, wherein the heat storage material is a granular heat storage material in which the powdery heat storage capsule is formed into a granular shape with a binder.   The method for producing an adsorbent with a heat storage function according to claim 1 or 2, wherein the adsorbent with a heat storage function is an integrally formed adsorbent with a heat storage function obtained by mixing the heat storage material and the adsorbent together with a binder. .   The adsorbent with a heat storage function manufactured by the manufacturing method of the adsorbent with a heat storage function as described in any one of Claims 1-3.   A canister formed by filling a case with the adsorbent with a heat storage function manufactured by the method for manufacturing an adsorbent with a heat storage function according to any one of claims 1 to 3.

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