WO2019027046A1 - Method for producing thermal insulation material, and composite thermal insulation material - Google Patents

Method for producing thermal insulation material, and composite thermal insulation material Download PDF

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Publication number
WO2019027046A1
WO2019027046A1 PCT/JP2018/029250 JP2018029250W WO2019027046A1 WO 2019027046 A1 WO2019027046 A1 WO 2019027046A1 JP 2018029250 W JP2018029250 W JP 2018029250W WO 2019027046 A1 WO2019027046 A1 WO 2019027046A1
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Prior art keywords
gel
heat insulating
insulating material
fiber structure
aqueous solution
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PCT/JP2018/029250
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French (fr)
Japanese (ja)
Inventor
依子 下村
剛 安達
永山　健一
中西　和樹
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株式会社サムスン日本研究所
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Publication of WO2019027046A1 publication Critical patent/WO2019027046A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/113—Silicon oxides; Hydrates thereof
    • C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
    • C01B33/16—Preparation of silica xerogels
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
    • D04H1/542—Adhesive fibres
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
    • D04H1/74—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being orientated, e.g. in parallel (anisotropic fleeces)
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L59/00—Thermal insulation in general
    • F16L59/02—Shape or form of insulating materials, with or without coverings integral with the insulating materials

Definitions

  • the present invention relates to a method of manufacturing a heat insulating material, and a composite heat insulating material.
  • Patent Document 1 discloses that a wet gel is prepared by hydrolyzing / condensing an alkoxysilane or an oligomer thereof, and drying the wet gel to reduce the mean free path of gas molecules at atmospheric pressure or less. Techniques for obtaining porous gels with pores have been described.
  • a porous gel having a silica skeleton and having voids formed therein is produced by polymerizing an alkoxysilane compound as a gel material in an aqueous solution to form a gel, and then drying the solvent.
  • a method of drying the solvent for example, a supercritical drying method using carbon dioxide in a supercritical state, a solvent substitution method of replacing the solvent with a low polar solvent, and the like exist.
  • An object of the present invention is to provide a heat insulating material using a porous gel having a silica skeleton, which is low in cost and excellent in heat insulating performance.
  • the method for producing a heat insulating material to which the present invention is applied is such that the amount of the trialkoxysilane compound and the tetraalkoxysilane compound is in the range of 4% to 10% of the total volume of the alkoxysilane compound.
  • the aqueous solution containing the gel raw material blended in water, water, and a surfactant and containing substantially no alcohol is hydrolyzed after the alkoxysilane compound is hydrolyzed to form a sol, and then the alkoxysilane compound is
  • the method is a method for producing a heat insulating material, in which a polymerization reaction is performed to form a gel, and the gel is washed with alcohol, solvent-replaced with hexane, and dried.
  • the alkoxysilane compound is subjected to a polymerization reaction to form a gel-forming fiber structure including the gel, and the gel-forming fiber structure is washed with alcohol.
  • it may be characterized by drying.
  • it can be characterized by impregnating the said aqueous solution with the nonwoven fabric in which fibers were melt
  • the aqueous solution may be impregnated with the fiber structure that has been subjected to plasma treatment or surface treatment with a silane coupling agent.
  • the fiber structure may be characterized in that the aqueous solution is impregnated with the aligned fibers.
  • hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride can be used as the surfactant.
  • the composite heat insulating material to which the present invention is applied is formed by polymerizing a fiber structure, and a trialkoxysilane compound and a tetraalkoxysilane compound, which are held inside the fiber structure. It has a porous structure formed by a silica skeleton, the specific surface area measured by the BET method is in the range of 550 m 2 / g to 700 m 2 / g, and the pore volume measured by the BJH method is 3.0 cm
  • the silica skeleton of the porous gel may be characterized by including a skeleton structure derived from the tetraalkoxysilane compound in a range of 4% to 10%.
  • the fiber structure may be a non-woven fabric in which fibers are fused with a binder resin.
  • the fiber structure may be characterized in that it is subjected to plasma treatment or surface treatment with a silane coupling agent.
  • the fiber structure can be characterized in that the fiber orientations are aligned.
  • FIG. 1 is a view showing a schematic configuration of a composite heat insulating material 1 to which the present embodiment is applied.
  • the composite heat insulating material 1 is a composite of a fiber structure 2 and a porous gel 3.
  • the composite heat insulating material 1 has a structure in which the porous gel 3 is held in the gap between the fibers 2 a constituting the fiber structure 2.
  • the fiber structure 2 is a sheet-like member in which a plurality of fibers 2a are intertwined, and a void is formed between the fibers 2a.
  • the fiber structure 2 for example, non-woven fabric or woven fabric can be used, and it is preferable to use non-woven fabric.
  • the material of the non-woven fabric used as the fiber structure 2 include vinylon fibers, polypropylene fibers, glass fibers (glass fibers), aramid fibers, nylon fibers, polyethylene fibers, cellulose fibers and the like. One of these may be used alone, or two or more of these may be used in combination.
  • the fiber structure 2 it is preferable to use a non-woven fabric made of vinylon fiber or polypropylene fiber.
  • a non-woven fabric made of vinylon fibers or polypropylene fibers as the fiber structure, the adhesion between the fibers 2a constituting the fiber structure 2 and the porous gel 3 is improved. Thereby, detachment of the porous gel 3 from the fiber structure 2 is suppressed.
  • the fibers 2a which comprise a nonwoven fabric are melt
  • the fibers 2a of the fiber structure 2 may be fused via a binder resin, or the fibers 2a may be directly fused.
  • the nonwoven fabric which consists of glass fibers (glass fiber) especially as the fiber structure 2 it is preferable to use the nonwoven fabric with which glass fibers were melt
  • the strength of the fiber structure 2 is improved, and the entire composite heat insulating material 1 is less likely to be crushed during the manufacturing process or use.
  • the pores in the porous gel 3 held by the fiber structure 2 are less likely to be crushed, and the decrease in the heat insulating performance of the composite heat insulating material 1 is suppressed.
  • the porous gel 3 is easily held in the fiber structure 2. Thereby, the thermal conductivity of the composite heat insulating material 1 can be reduced.
  • the binder resin for fusing the fibers 2a of the fiber structure 2 is not particularly limited, and examples thereof include thermoplastic resins such as polyethylene terephthalate (PET), polyethylene, polypropylene, polystyrene and vinyl chloride, and phenol A thermosetting resin such as a resin, an epoxy resin, or a melamine resin can be used. Among these, it is preferable to use PET.
  • PET polyethylene terephthalate
  • PET polyethylene
  • polypropylene polystyrene and vinyl chloride
  • phenol A thermosetting resin such as a resin, an epoxy resin, or a melamine resin
  • PET it is preferable to use PET.
  • the orientation of the fiber 2a which comprises a nonwoven fabric is arrange
  • a non-woven fabric which has been subjected to a process for aligning the orientation of the fibers 2 a in the paper making process in the production of the non-woven fabric.
  • the fiber structure 2 is subjected to coating treatment such as plasma treatment and corona treatment or coating treatment with a silane coupling agent.
  • coating treatment such as plasma treatment and corona treatment or coating treatment with a silane coupling agent.
  • the hydrophilicity of the fiber structure 2 is improved.
  • the raw material aqueous solution of the porous gel 3 becomes easy to permeate between the fibers 2a of the fiber structure 2.
  • the adhesion between the fibers 2a of the fiber structure 2 and the porous gel 3 is improved, and the detachment of the porous gel 3 from the fiber structure 2 is suppressed.
  • the porous gel 3 of the present embodiment is a so-called xerogel obtained by drying a gel having a silica skeleton formed by sterically linking silicon dioxide by solvent substitution.
  • a plurality of voids (pores) are formed between silica skeletons.
  • the porous gel 3 of this embodiment is obtained by polymerizing a trialkoxysilane compound and a tetraalkoxysilane compound as an alkoxysilane compound to form a gel, and drying the gel by solvent substitution.
  • the size of the pores of the porous gel 3 is equal to or less than the mean free path of gas molecules under atmospheric pressure. Therefore, in the composite heat insulating material 1 of the present embodiment, the porous gel 3 suppresses the heat conduction due to the convection of air and maintains the heat insulating property.
  • the porous gel 3 preferably has a specific surface area by BET method in the range of 550 m 2 / g to 700 m 2 / g.
  • the specific surface area of the porous gel 3 according to the BET method is less than 550 m 2 / g, the solid component constituting the silica skeleton in the porous gel 3 is increased. For this reason, the heat conduction through the silica skeleton increases, and the heat conductivity of the composite heat insulating material 1 tends to increase.
  • the specific surface area of the porous gel 3 by BET method is larger than 700 m 2 / g, the solid component constituting the silica skeleton in the porous gel 3 is reduced. For this reason, the void of the porous gel 3 is easily crushed during the manufacturing process or use of the composite heat insulating material 1, and the thermal conductivity of the composite heat insulating material 1 tends to be large.
  • the porous gel 3, the pore volume by the BJH method is preferably in the range of less 3.0 cm 3 / g or more 4.0 cm 3 / g.
  • the pore volume of the porous gel 3 by the BJH method is less than 3.0 cm 3 / g, the solid component constituting the silica skeleton in the porous gel 3 is increased. For this reason, the heat conduction through the silica skeleton increases, and the heat conductivity of the composite heat insulating material 1 tends to increase.
  • the pore volume of the porous gel 3 by the BJH method is larger than 4.0 cm 3 / g, the solid component constituting the silica skeleton in the porous gel 3 is reduced. For this reason, the void of the porous gel 3 is easily crushed during the manufacturing process or use of the composite heat insulating material 1, and the thermal conductivity of the composite heat insulating material 1 tends to be large.
  • the thermal conductivity of the composite heat insulating material 1 of the present embodiment is in the range of not less than 12.5 mW / mK and not more than 14.0 mW / mK.
  • the composite heat insulating material 1 of the present embodiment is superior to, for example, a heat insulating material composed of a hard urethane foam having a thermal conductivity of about 20 mW / mK or a foamed polystyrene having a thermal conductivity of about 30 to 40 mW / mK.
  • a heat insulating material composed of a hard urethane foam having a thermal conductivity of about 20 mW / mK or a foamed polystyrene having a thermal conductivity of about 30 to 40 mW / mK.
  • the manufacturing method of the composite heat insulating material 1 to which this Embodiment is applied is demonstrated.
  • the composite heat insulating material 1 prepares a raw material aqueous solution, and immerses the fiber structure 2 in the raw material aqueous solution. And a raw material aqueous solution is heated and a gel is formed between the fibers 2a of the fiber structure 2 by polymerizing the alkoxysilane compound mentioned later. Subsequently, the fiber structure 2 in which the gel is formed is washed with methanol and then solvent-replaced with hexane.
  • a raw material aqueous solution containing an alkoxysilane compound which is a gel raw material, a surfactant, water and the like in a predetermined ratio is prepared. Specifically, an alkoxysilane compound, a surfactant, and the like are added to an aqueous solution adjusted to be acidic with an acid catalyst such as acetic acid, and dissolved to dissolve the alkoxysilane compound so that it is solified. Prepare the aqueous solution.
  • an alcohol such as methanol or ethanol is not added to the raw material aqueous solution used for producing the composite heat insulating material 1 of the present embodiment.
  • a trialkoxysilane compound and a tetraalkoxysilane compound are used as an alkoxysilane compound which is a gel material, and the tetraalkoxysilane compound is in a range of 4% to 10% with respect to the total volume of the alkoxysilane compound.
  • the thermal conductivity of the composite heat insulating material 1 tends to be large.
  • the blending amount of the tetraalkoxysilane compound in the alkoxysilane compound is less than 4%, the strength of the skeleton structure in the porous gel 3 is reduced, and the voids are easily collapsed. In this case, the thermal conductivity of the composite heat insulating material 1 tends to be large.
  • the blending amount of the tetraalkoxysilane compound in the alkoxysilane compound is more than 10%, there is a possibility that an aggregate is formed in the step of gelation described later. In this case, the skeletal structure of the porous gel 3 may be uneven, and the thermal conductivity of the composite heat insulating material 1 tends to be large.
  • trialkoxysilane compounds include trimethoxysilane, triethoxysilane, monomethyltrimethoxysilane, monomethyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane and the like. Among these, it is preferable to use trimethoxysilane or triethoxysilane, and it is more preferable to use trimethoxysilane.
  • tetraalkoxysilane compounds include tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, and tetra n-butoxysilane. Among these, it is preferable to use tetramethoxysilane or tetraethoxysilane, and it is more preferable to use tetramethoxysilane.
  • the alkoxysilane compound may contain a dialkoxysilane compound or a monoalkoxysilane compound in addition to the trialkoxysilane compound and the tetraalkoxysilane compound.
  • the surfactant is added in order to improve the dispersibility of the trialkoxysilane compound and the tetraalkoxysilane compound in the raw material aqueous solution in the process of causing the alkoxysilane compound to undergo polymerization reaction and gelation.
  • an appropriate phase separation structure of the alkoxysilane compound is formed in the aqueous solution of the raw material.
  • the skeletal structure of the porous gel 3 becomes uniform, and fine voids are uniformly formed in the porous gel 3.
  • the surfactant is not particularly limited, and for example, at least one selected from cationic surfactants, anionic surfactants, and amphoteric surfactants can be used. Among these, it is preferable to use a cationic surfactant, and in particular, it is more preferable to use hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride. By using hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride as a surfactant, the porous gel 3 in which the skeletal structure and the voids are uniformly formed can be obtained.
  • the amount of surfactant added to the raw material aqueous solution varies depending on the type of alkoxysilane compound and surfactant, but can be, for example, in the range of 80 g to 86 g per 1000 mL (1000 cm 3 ) volume of alkoxysilane compound. .
  • an acid catalyst for promoting hydrolysis of the alkoxysilane compound to the raw material aqueous solution.
  • the acid catalyst acetic acid, hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, phosphoric acid, bromic acid, oxalic acid, succinic acid and the like can be mentioned. Among these, it is preferable to use acetic acid.
  • the polymerization reaction is promoted by raising the pH of the raw material aqueous solution in the gelation step of the alkoxysilane compound.
  • urea is added to the aqueous solution of raw material, ammonia is generated by heating in the polymerization process described later, and the pH of the aqueous solution of raw material is raised.
  • Examples of the base catalyst include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and cesium hydroxide, and ammonium compounds such as ammonium hydroxide, ammonium fluoride and ammonium bromide.
  • alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and cesium hydroxide
  • ammonium compounds such as ammonium hydroxide, ammonium fluoride and ammonium bromide.
  • the raw material aqueous solution used for manufacture of the composite heat insulating material 1 of this Embodiment does not contain alcohol.
  • an alcohol which dissolves the alkoxysilane compound and has compatibility with water is added to the raw material aqueous solution for producing the gel using the alkoxysilane compound. It is common to do.
  • the present embodiment by using an alkoxysilane compound in which a trialkoxysilane compound and a tetraalkoxysilane compound are blended in the above ratio, and adding a surfactant, the addition of alcohol to the raw material aqueous solution is performed. Is unnecessary.
  • the fact that the raw material aqueous solution does not substantially contain alcohol means that alcohol is not positively added as a solvent to the raw material aqueous solution.
  • the fiber structure 2 which has been subjected to a treatment such as a coating treatment or a fusion with a binder resin in advance is immersed in the adjusted raw material aqueous solution.
  • a treatment such as a coating treatment or a fusion with a binder resin in advance
  • the fiber structure 2 is immersed in the raw material aqueous solution so as to be completely immersed.
  • the raw material aqueous solution spreads over the fibers 2 a of the fiber structure 2.
  • the raw material aqueous solution in which the fiber structure 2 is immersed is heated to a predetermined temperature to cause the alkoxysilane compound contained in the raw material aqueous solution to undergo a polymerization reaction to gelate.
  • a polymerization reaction to gelate.
  • ammonia is generated from urea contained in the aqueous solution of raw material, and the pH of the aqueous solution of raw material rises.
  • the polymerization reaction of the alkoxysilane compound is promoted, the trialkoxysilane compound and the tetraalkoxysilane compound are polymerized, and a gel is formed between the fibers 2 a of the fiber structure 2.
  • generated between the fibers 2a may be called a gel production fiber structure.
  • the heating temperature of the raw material aqueous solution can be, for example, in the range of 60 ° C. or more and 80 ° C. or less.
  • the time for heating and gelling the raw material aqueous solution may vary depending on the heating temperature and the like, but can be, for example, in the range of 24 hours to 120 hours.
  • the curing temperature can be, for example, in the range of 60 ° C. or more and 80 ° C. or less.
  • curing time changes with curing temperature etc. it can be made into the range of 5 hours or more and 72 hours or less, for example.
  • curing may be performed while the gel-forming fiber structure is continuously immersed in the raw material aqueous solution, or the gel-forming fiber structure may be removed from the raw material aqueous solution and immersed in pure water or the like.
  • the gel-forming fiber structure is washed with alcohol.
  • the surfactant remaining in the pores of the gel of the gel-formed fiber structure, the unreacted alkoxysilane compound, water and the like are removed by washing with alcohol.
  • the alcohol used for the washing those having high affinity to the alkoxysilane compound, water, surfactant, and high affinity to hexane used for solvent substitution described later are used.
  • Specific examples of such alcohols include methanol, ethanol, isopropyl alcohol and the like. Among these, it is preferable to use methanol.
  • the skeletal structure of the gel shrinks as the water and surfactant decrease in the drying step described later.
  • the specific surface area and pore volume of the obtained porous gel 3 may be reduced, and the heat insulation efficiency of the composite heat insulating material 1 may be reduced.
  • by washing the gel-forming fiber structure with alcohol before solvent substitution it is possible to suppress the water and the surfactant from remaining in the gel.
  • the gel produced between the fibers 2a of the fiber structure 2 is dried by heating the solvent-replaced gel-formed fiber structure with hexane at a predetermined temperature to completely remove the hexane, and the porous gel is obtained.
  • the step of drying the gel-forming fiber structure does not have to be performed in a high pressure environment as in the supercritical drying method, and can be performed in a normal pressure environment or a reduced pressure environment.
  • an alkoxysilane compound containing a trialkoxysilane compound and a tetraalkoxysilane compound in a predetermined ratio is used as a gel material.
  • a surfactant is added to the raw material aqueous solution.
  • the inside of the pores of the gel is replaced with hexane having a small surface tension.
  • the composite heat insulating material 1 in which the porous gel 3 is formed between the fibers 2 a of the fiber structure 2 can be obtained.
  • the solvent is dried to manufacture the porous gel 3 without performing the supercritical drying method. doing.
  • cost, effort, time, etc. which manufacture of composite heat insulating material 1 requires can be reduced.
  • an alkoxysilane compound containing a trialkoxysilane compound and a tetraalkoxysilane compound in a predetermined ratio is used as the gel material of the porous gel 3. Furthermore, in addition to the alkoxysilane compound, a surfactant is added to the raw material aqueous solution. Furthermore, alcohol is not added to the raw material aqueous solution. As a result, an appropriate phase separation structure of an appropriate alkoxysilane compound is formed in the aqueous solution of the raw material, and a porous gel 3 in which fine voids are uniformly formed can be obtained. And the heat insulation efficiency of the composite heat insulating material 1 with which the fiber structure 2 and the porous gel 3 were compounded can be improved.
  • the composite heat insulating material of the present embodiment can be employed for products that require heat insulation such as cold insulation and heat retention.
  • examples of such products include, but are not limited to, refrigerators, freezers, showcases, washing and drying machines, vending machines, construction walls, and the like.
  • Example 1 (Raw material aqueous solution adjustment process) To 1000 mL of 5 mM aqueous acetic acid solution, 40 g of hexadecyltrimethylammonium bromide as a surfactant was added and stirred, and further 300 g of urea was added and stirred for 1 hour. Into this aqueous solution, 475 mL of trimethoxysilane as a trialkoxysilane compound and 25 mL of tetramethoxysilane as a tetraalkoxysilane compound were added as gel raw materials and stirred for 30 minutes.
  • the transparent raw material aqueous solution in which the alkoxysilane compound was hydrolyzed was obtained.
  • the content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in the aqueous solution of the raw material is 5%.
  • the raw material aqueous solution contains substantially no alcohol.
  • a fiber structure 2 formed by overlapping 14.6 g of a PET non-woven fabric (14.5 cm square) with a raw material aqueous solution and sewing them together with a yarn was immersed in the above raw material aqueous solution in a completely immersed state . Then, it was left to stand in an oven at 60 ° C. for 4 days to make a gel between the fibers 2 a of the fiber structure 2. Thereafter, the fiber structure 2 (gel-forming fiber structure) in which the gel is formed between the fibers 2a is taken out from the raw material aqueous solution, and immersed in pure water in a completely immersed state for one day at 60.degree. Time) healed.
  • the fiber structure 2 (gel-forming fiber structure) in which the gel was formed between the fibers 2a was taken out from the pure water and washed with methanol. Subsequently, the gel-formed fiber structure after washing was immersed in hexane while completely immersed, and the inside of the pores of the gel was replaced with hexane.
  • the thermal conductivity of the obtained composite heat insulating material 1 was measured using a NETZSCH HFM436 / 3, and was 13.5 mW / mK. Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 680 m ⁇ 2 > / g, and the pore volume by BJH method was 3.6 cm ⁇ 3 > / g. Furthermore, the porosity of the gel calculated from the density of quartz was 95% for the composite heat insulating material 1 obtained.
  • Example 2 A composite heat insulating material 1 was obtained in the same manner as in Example 1 except that 465 mL of trimethoxysilane and 35 mL of tetramethoxysilane were used as the alkoxysilane compound used for the raw material aqueous solution.
  • the content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in this raw material aqueous solution is 7%.
  • the thermal conductivity of the obtained composite heat insulating material 1 was measured using HFM436 / 3 manufactured by NETZSCH, and was 14.0 mW / mK. Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 640 m ⁇ 2 > / g, and the pore volume by BJH method was 3.4 cm ⁇ 3 > / g. Furthermore, the porosity of the gel calculated from the density of quartz was 94.8% for the composite heat insulating material 1 obtained.
  • Example 3 A composite heat insulating material was prepared in the same manner as in Example 1, except that 450 mL of trimethoxysilane and 50 mL of tetramethoxysilane were used as the alkoxysilane compound used in the raw material aqueous solution and 43 g of hexadecyltrimethylammonium chloride was used as the surfactant. I got one. The content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in the aqueous solution of the raw material is 10%.
  • the thermal conductivity of the obtained composite heat insulating material 1 was measured using HFM436 / 3 manufactured by NETZSCH, and was 12.5 mW / mK. Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 700 m ⁇ 2 > / g, and the pore volume by BJH method was 4.0 cm ⁇ 3 > / g. Furthermore, the porosity of the gel calculated from the density of quartz was 95% for the composite heat insulating material 1 obtained.
  • Example 4 A composite heat insulating material 1 was obtained in the same manner as in Example 1 except that 40 g of hexadecyltrimethylammonium chloride was used as a surfactant used for the raw material aqueous solution.
  • the thermal conductivity of the obtained composite heat insulating material 1 was measured using HFM436 / 3 manufactured by NETZSCH, and was 13.8 mW / mK. Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 650 m ⁇ 2 > / g, and the pore volume by BJH method was 3.5 cm ⁇ 3 > / g. Furthermore, the porosity of the gel calculated from the density of quartz was 94.8% for the composite heat insulating material 1 obtained.
  • Example 5 The same procedure as in Example 1 was repeated, except that 14.6 g of a glass fiber non-woven fabric (14.5 cm square) was overlapped and sewed with yarn as the fiber structure 2 to be immersed in the raw material aqueous solution. The composite heat insulating material 1 was obtained.
  • the thermal conductivity of the obtained composite heat insulating material 1 was measured using a NETZSCH HFM436 / 3, and was 13.5 mW / mK. Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 680 m ⁇ 2 > / g, and the pore volume by BJH method was 3.6 cm ⁇ 3 > / g. Furthermore, the porosity of the gel calculated from the density of quartz was 95% for the composite heat insulating material 1 obtained.
  • Example 6 As a fiber structure 2 to be immersed in a raw material aqueous solution, 14.6 g of a glass fiber non-woven fabric (14.5 cm square) is overlapped and sewed with a thread, oxygen Plasma under conditions of 500 W for 180 seconds with PC-1000 made by SAMCO. A composite heat insulating material was obtained in the same manner as in Example 1 except that the fiber structure 2 formed by irradiating the same was used.
  • the thermal conductivity of the obtained composite heat insulating material 1 was measured using HFM436 / 3 manufactured by NETZSCH, and was 12.5 mW / mK. Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 700 m ⁇ 2 > / g, and the pore volume by BJH method was 4.0 cm ⁇ 3 > / g. Furthermore, the porosity of the gel calculated from the density of quartz was 95.2% for the composite heat insulating material 1 obtained.
  • Comparative Example 1 A composite heat insulating material 1 was obtained in the same manner as in Example 1 except that 485 mL of trimethoxysilane and 15 mL of tetramethoxysilane were used as the alkoxysilane compound used for the raw material aqueous solution.
  • the content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in the aqueous solution of the raw material is 3%.
  • the thermal conductivity of the obtained composite heat insulating material 1 measured using NETM SCH HFM436 / 3 was 16.5 mW / mK.
  • the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 510 m ⁇ 2 > / g, and the pore volume by BJH method was 4.1 cm ⁇ 3 > / g.
  • the porosity of the gel calculated from the density of quartz was 93.5% for the composite heat insulating material 1 obtained.
  • Comparative Example 2 A composite heat insulating material 1 was obtained in the same manner as in Example 1 except that 400 mL of trimethoxysilane and 100 mL of tetramethoxysilane were used as the alkoxysilane compound used for the raw material aqueous solution.
  • the content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in the aqueous solution of the raw material is 20%.
  • the thermal conductivity of the obtained composite heat insulating material 1 measured using NETM SCH HFM436 / 3 was 16.2 mW / mK.
  • the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 530 m ⁇ 2 > / g, and the pore volume by BJH method was 4.0 cm ⁇ 3 > / g.
  • the porosity of the gel calculated from the density of quartz was 93.8% for the composite heat insulating material 1 obtained.
  • Comparative Example 3 The composite heat insulating material 1 was obtained like Example 1 except having used the mixed solvent of 300 mL of methanol, and 700 mL of water as a solvent with respect to raw material aqueous solution.
  • the thermal conductivity of the obtained composite heat insulating material 1 was measured using a NETZSCH HFM 436/3, and was 20 mW / mK. Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 460 m ⁇ 2 > / g, and the pore volume by BJH method was 8.0 cm ⁇ 3 > / g. Furthermore, the porosity of the gel calculated from the density of quartz was 93% for the composite heat insulating material 1 obtained.
  • Table 1 shows the configuration and evaluation results of the composite heat insulator 1 of Examples 1 to 6, and Table 2 shows the configuration and evaluation results of the composite heat insulator 1 of Comparative Examples 1 to 3.
  • a trialkoxysilane compound and a tetraalkoxysilane compound are used as an alkoxysilane compound which is a gel material, and the tetraalkoxysilane compound is in the range of 4% to 10% with respect to the total volume of the alkoxysilane compound.
  • the raw material aqueous solution contains substantially no alcohol while the surfactant is added to the raw material aqueous solution and the raw material aqueous solution contains substantially no alcohol, a composite heat insulating material having a high thermal insulation performance with uniformly formed skeleton structure and voids. It was confirmed that 1 was obtained.
  • Comparative Example 1 where the content of the tetraalkoxysilane compound is less than 4% relative to the total volume of the alkoxysilane compound, Comparative Example 2 more than 10%, and Comparative Example 3 in which the raw material aqueous solution contains alcohol. It has been confirmed that the heat insulating performance of the composite heat insulating material 1 is reduced as compared with Examples 1 to 6.
  • Example 1 when Example 1-Example 6 are compared with each other, in Example 6 which performed the plasma processing with respect to the fiber structure 2 (glass fiber), the plasma processing was not performed to the fiber structure 2 (glass fiber) As compared with Example 5, it was confirmed that the thermal conductivity of the composite heat insulating material 1 is lowered and the heat insulating performance is enhanced.

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Abstract

This composite thermal insulation material 1 is able to be obtained by a process wherein: an aqueous solution, which contains water, a surfactant and a gel starting material that is obtained by blending a trialkoxysilane compound and a tetraalkoxysilane compound so that the amount of the tetraalkoxysilane compound relative to the total volume of alkoxysilane compounds is within the range of from 4% to 10% (inclusive), while containing substantially no alcohol, is heated after hydrolyzing the alkoxysilane compounds so as to produce a sol, thereby causing a polymerization reaction of the alkoxysilane compounds and forming a gel; and the thus-obtained gel is cleaned with an alcohol, is then subjected to solvent exchange by means of hexane, and is subsequently dried.

Description

断熱材の製造方法、および複合断熱材Method of manufacturing insulation and composite insulation
　本発明は、断熱材の製造方法、および複合断熱材に関する。 The present invention relates to a method of manufacturing a heat insulating material, and a composite heat insulating material.
　従来技術として、特許文献１には、アルコキシシランあるいはそのオリゴマーを加水分解・縮重合させることで湿潤ゲルを作製し、これを乾燥させることで、大気圧下での気体分子の平均自由行程以下の孔を有する多孔質ゲルを得る技術が記載されている。 As a prior art, Patent Document 1 discloses that a wet gel is prepared by hydrolyzing / condensing an alkoxysilane or an oligomer thereof, and drying the wet gel to reduce the mean free path of gas molecules at atmospheric pressure or less. Techniques for obtaining porous gels with pores have been described.
　一般に、シリカ骨格を有し内部に空隙が形成された多孔質ゲルは、水溶液中でゲル原料となるアルコキシシラン化合物を重合反応させてゲルを形成した後、溶媒を乾燥させることにより作製される。溶媒を乾燥させる方法としては、例えば超臨界状態の二酸化炭素を用いる超臨界乾燥法や、溶媒を低極性溶媒に置換する溶媒置換法等が存在する。 In general, a porous gel having a silica skeleton and having voids formed therein is produced by polymerizing an alkoxysilane compound as a gel material in an aqueous solution to form a gel, and then drying the solvent. As a method of drying the solvent, for example, a supercritical drying method using carbon dioxide in a supercritical state, a solvent substitution method of replacing the solvent with a low polar solvent, and the like exist.
特開２００４－１０４２４号公報JP 2004-10424 A
　溶媒を乾燥させる方法として超臨界乾燥法を採用する場合、乾燥に用いる設備のコストが高く、また乾燥に時間や手間を要する。
　一方、溶媒を乾燥させる方法として溶媒置換法を採用する場合、ゲル原料として用いるアルコキシシラン化合物の種類や原料水溶液の配合等によっては、置換した溶媒を乾燥させる際にゲルの骨格構造が収縮、破裂して、多孔質ゲルの比表面積や細孔容積が減少するおそれがある。そして、この多孔質ゲルを断熱材として用いた場合には、断熱性能が低下するおそれがある。 When supercritical drying is employed as a method for drying the solvent, the cost of equipment used for drying is high, and drying requires time and effort.
On the other hand, when the solvent substitution method is adopted as the method of drying the solvent, the skeleton structure of the gel shrinks or bursts when drying the substituted solvent depending on the kind of alkoxysilane compound used as the gel raw material and the composition of the raw material aqueous solution. As a result, the specific surface area and pore volume of the porous gel may be reduced. And when this porous gel is used as a heat insulating material, there exists a possibility that heat insulation performance may fall.
　本発明は、シリカ骨格を有する多孔質ゲルを用いた断熱材であって、低コストで且つ断熱性能に優れた断熱材を提供することを目的とする。 An object of the present invention is to provide a heat insulating material using a porous gel having a silica skeleton, which is low in cost and excellent in heat insulating performance.
　本発明が適用される断熱材の製造方法は、トリアルコキシシラン化合物とテトラアルコキシシラン化合物とを当該テトラアルコキシシラン化合物がアルコキシシラン化合物の総体積に対して４％以上１０％以下の範囲となるように配合したゲル原料と、水と、界面活性剤とを含み、且つアルコールを実質含まない水溶液を、当該アルコキシシラン化合物を加水分解してゾルを生成させたうえで加熱し、当該アルコキシシラン化合物を重合反応させてゲルを生成し、前記ゲルをアルコールで洗浄し、ヘキサンで溶媒置換した後、乾燥する断熱材の製造方法である。
　ここで、前記水溶液に対して繊維構造物を含浸した後、前記アルコキシシラン化合物を重合反応させて、前記ゲルを包含するゲル生成繊維構造物を生成し、前記ゲル生成繊維構造物をアルコールで洗浄し、ヘキサンで溶媒置換した後、乾燥することを特徴とすることができる。
　また、前記繊維構造物として、繊維同士がバインダ樹脂により融着された不織布を、前記水溶液に含浸することを特徴とすることができる。
　さらに、プラズマ処理またはシランカップリング剤による表面処理が施された前記繊維構造物を前記水溶液に含浸することを特徴とすることができる。
　さらにまた、繊維の配向が揃えられた前記繊維構造物を前記水溶液に含浸することを特徴とすることができる。
　また、前記界面活性剤として、臭化ヘキサデシルトリメチルアンモニウムまたは塩化ヘキサデシルトリメチルアンモニウムを用いることを特徴とすることができる。 The method for producing a heat insulating material to which the present invention is applied is such that the amount of the trialkoxysilane compound and the tetraalkoxysilane compound is in the range of 4% to 10% of the total volume of the alkoxysilane compound. The aqueous solution containing the gel raw material blended in water, water, and a surfactant and containing substantially no alcohol is hydrolyzed after the alkoxysilane compound is hydrolyzed to form a sol, and then the alkoxysilane compound is The method is a method for producing a heat insulating material, in which a polymerization reaction is performed to form a gel, and the gel is washed with alcohol, solvent-replaced with hexane, and dried.
Here, after impregnating the fiber structure with the aqueous solution, the alkoxysilane compound is subjected to a polymerization reaction to form a gel-forming fiber structure including the gel, and the gel-forming fiber structure is washed with alcohol. And after solvent substitution with hexane, it may be characterized by drying.
Moreover, it can be characterized by impregnating the said aqueous solution with the nonwoven fabric in which fibers were melt | fused by binder resin as said fiber structure.
Furthermore, the aqueous solution may be impregnated with the fiber structure that has been subjected to plasma treatment or surface treatment with a silane coupling agent.
Furthermore, the fiber structure may be characterized in that the aqueous solution is impregnated with the aligned fibers.
In addition, hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride can be used as the surfactant.
　また、他の観点からとらえると、本発明が適用される複合断熱材は、繊維構造物と、前記繊維構造物の内部に保持され、トリアルコキシシラン化合物とテトラアルコキシシラン化合物とを重合させてなるシリカ骨格により形成される多孔質構造を有し、ＢＥＴ法により測定される比表面積が５５０ｍ2／ｇ以上７００ｍ2／ｇ以下の範囲であり、ＢＪＨ法により測定される細孔容積が３．０ｃｍ3／ｇ以上４．０ｃｍ3／ｇ以下の範囲である多孔質ゲルとを含み、熱伝導率が１２．５ｍＷ／ｍＫ以上１４．０ｍＷ／ｍＫ以下の範囲である複合断熱材である。
　ここで、前記多孔質ゲルの前記シリカ骨格は、前記テトラアルコキシシラン化合物に由来する骨格構造を４％以上１０％以下の範囲で含むことを特徴とすることができる。
　また、前記繊維構造物は、繊維同士がバインダ樹脂で融着された不織布であることを特徴とすることができる。
　さらに、前記繊維構造物は、プラズマ処理またはシランカップリング剤による表面処理が施されていることを特徴とすることができる。
　さらにまた、前記繊維構造物は、繊維配向が揃えられていることを特徴とすることができる。 From another viewpoint, the composite heat insulating material to which the present invention is applied is formed by polymerizing a fiber structure, and a trialkoxysilane compound and a tetraalkoxysilane compound, which are held inside the fiber structure. It has a porous structure formed by a silica skeleton, the specific surface area measured by the BET method is in the range of 550 m 2 / g to 700 m 2 / g, and the pore volume measured by the BJH method is 3.0 cm A composite heat insulating material including a porous gel in the range of 3 / g to 4.0 cm 3 / g and having a thermal conductivity in the range of 12.5 mW / mK to 14.0 mW / mK.
Here, the silica skeleton of the porous gel may be characterized by including a skeleton structure derived from the tetraalkoxysilane compound in a range of 4% to 10%.
Further, the fiber structure may be a non-woven fabric in which fibers are fused with a binder resin.
Furthermore, the fiber structure may be characterized in that it is subjected to plasma treatment or surface treatment with a silane coupling agent.
Furthermore, the fiber structure can be characterized in that the fiber orientations are aligned.
　本発明によれば、シリカ骨格を有する多孔質ゲルを用いた断熱材であって、低コストで且つ断熱性能に優れた断熱材を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, it is a heat insulating material using the porous gel which has a silica structure, Comprising: The heat insulating material which was low-cost and excellent in the heat insulation performance can be provided.
本実施の形態が適用される複合断熱材の概略構成を示した図である。It is the figure which showed schematic structure of the composite heat insulating material to which this Embodiment is applied.
　以下、本発明の実施の形態について詳細に説明する。
［複合断熱材］
　図１は、本実施の形態が適用される複合断熱材１の概略構成を示した図である。複合断熱材１は、繊維構造物２と、多孔質ゲル３とが複合化されている。具体的には、複合断熱材１は、図１に示すように、繊維構造物２を構成する繊維２ａ同士の間隙に、多孔質ゲル３が保持された構造を有している。 Hereinafter, embodiments of the present invention will be described in detail.
[Compound insulation material]
FIG. 1 is a view showing a schematic configuration of a composite heat insulating material 1 to which the present embodiment is applied. The composite heat insulating material 1 is a composite of a fiber structure 2 and a porous gel 3. Specifically, as shown in FIG. 1, the composite heat insulating material 1 has a structure in which the porous gel 3 is held in the gap between the fibers 2 a constituting the fiber structure 2.
（繊維構造物）
　繊維構造物２は、複数の繊維２ａが絡み合わさったシート状の部材であり、繊維２ａ間には空隙が形成されている。繊維構造物２としては、例えば不織布や織布を用いることができ、不織布を用いることが好ましい。また、繊維構造物２として不織布を用いる場合、複数枚の不織布を、例えば糸で縫い合わせる等して重ねて用いてもよい。
　繊維構造物２として用いる不織布の材質としては、例えば、ビニロン繊維、ポリプロピレン繊維、ガラス繊維（グラスファイバ）、アラミド繊維、ナイロン繊維、ポリエチレン繊維、セルロース繊維等が挙げられる。これらは、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 (Fiber structure)
The fiber structure 2 is a sheet-like member in which a plurality of fibers 2a are intertwined, and a void is formed between the fibers 2a. As the fiber structure 2, for example, non-woven fabric or woven fabric can be used, and it is preferable to use non-woven fabric. Moreover, when using a nonwoven fabric as the fiber structure 2, you may overlap and use a plurality of nonwoven fabrics, for example by sewing with thread.
Examples of the material of the non-woven fabric used as the fiber structure 2 include vinylon fibers, polypropylene fibers, glass fibers (glass fibers), aramid fibers, nylon fibers, polyethylene fibers, cellulose fibers and the like. One of these may be used alone, or two or more of these may be used in combination.
　繊維構造物２としては、これらの中でも、ビニロン繊維またはポリプロピレン繊維からなる不織布を用いることが好ましい。繊維構造物としてビニロン繊維またはポリプロピレン繊維からなる不織布を用いることで、繊維構造物２を構成する繊維２ａと多孔質ゲル３との密着性が良好になる。これにより、繊維構造物２から多孔質ゲル３が脱離することが抑制される。 Among these, as the fiber structure 2, it is preferable to use a non-woven fabric made of vinylon fiber or polypropylene fiber. By using a non-woven fabric made of vinylon fibers or polypropylene fibers as the fiber structure, the adhesion between the fibers 2a constituting the fiber structure 2 and the porous gel 3 is improved. Thereby, detachment of the porous gel 3 from the fiber structure 2 is suppressed.
　また、繊維構造物２として不織布を用いる場合、不織布を構成する繊維２ａ同士が融着されていることが好ましい。なお、繊維構造物２の繊維２ａは、バインダ樹脂を介して融着されていてもよく、繊維２ａ同士が直接融着されていてもよい。特に、繊維構造物２としてガラス繊維（グラスファイバ）からなる不織布を用いる場合、ガラス繊維同士が融着された不織布を用いることが好ましい。 Moreover, when using a nonwoven fabric as the fiber structure 2, it is preferable that the fibers 2a which comprise a nonwoven fabric are melt | fused. The fibers 2a of the fiber structure 2 may be fused via a binder resin, or the fibers 2a may be directly fused. When using the nonwoven fabric which consists of glass fibers (glass fiber) especially as the fiber structure 2, it is preferable to use the nonwoven fabric with which glass fibers were melt | fused.
　繊維構造物２として繊維２ａ同士が融着された不織布を用いることで、繊維構造物２の強度が向上し、製造過程や使用時に複合断熱材１全体がつぶれにくくなる。この結果、繊維構造物２に保持される多孔質ゲル３内の孔がつぶれにくくなり、複合断熱材１の断熱性能の低下が抑制される。
　また、繊維構造物２として繊維２ａ同士が融着された不織布を用いることで、繊維構造物２内に多孔質ゲル３が保持されやすくなる。これにより、複合断熱材１の熱伝導率を低下させることができる。 By using a non-woven fabric in which the fibers 2a are fused together as the fiber structure 2, the strength of the fiber structure 2 is improved, and the entire composite heat insulating material 1 is less likely to be crushed during the manufacturing process or use. As a result, the pores in the porous gel 3 held by the fiber structure 2 are less likely to be crushed, and the decrease in the heat insulating performance of the composite heat insulating material 1 is suppressed.
In addition, by using a non-woven fabric in which the fibers 2 a are fused together as the fiber structure 2, the porous gel 3 is easily held in the fiber structure 2. Thereby, the thermal conductivity of the composite heat insulating material 1 can be reduced.
　繊維構造物２の繊維２ａ同士を融着するバインダ樹脂としては、特に限定されるものではないが、例えば、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレン、ポリプロピレン、ポリスチレン、塩化ビニル等の熱可塑性樹脂や、フェノール樹脂、エポキシ樹脂、メラミン樹脂等の熱硬化性樹脂等を用いることができる。これらの中でも、ＰＥＴを用いることが好ましい。 The binder resin for fusing the fibers 2a of the fiber structure 2 is not particularly limited, and examples thereof include thermoplastic resins such as polyethylene terephthalate (PET), polyethylene, polypropylene, polystyrene and vinyl chloride, and phenol A thermosetting resin such as a resin, an epoxy resin, or a melamine resin can be used. Among these, it is preferable to use PET.
　また、繊維構造物２として不織布を用いる場合、不織布を構成する繊維２ａの配向が所定方向に揃えられていることが好ましい。言い換えると、繊維構造物２として、不織布の製造における抄紙工程において繊維２ａの配向を揃える処理を行った不織布を用いることが好ましい。
　繊維構造物２として繊維２ａの配向が揃えられた不織布を用いることで、繊維２ａの配向が揃えられていない場合と比較して、複合断熱材１における熱伝導率を低下させることができる。 Moreover, when using a nonwoven fabric as the fiber structure 2, it is preferable that the orientation of the fiber 2a which comprises a nonwoven fabric is arrange | equalized by the predetermined direction. In other words, it is preferable to use, as the fiber structure 2, a non-woven fabric which has been subjected to a process for aligning the orientation of the fibers 2 a in the paper making process in the production of the non-woven fabric.
By using a non-woven fabric in which the orientations of the fibers 2a are aligned as the fiber structure 2, the thermal conductivity in the composite heat insulating material 1 can be reduced as compared with the case where the orientations of the fibers 2a are not aligned.
　さらに、繊維構造物２は、プラズマ処理、コロナ処理等のコーティング処理やシランカップリング剤によるコーティング処理が施されていることが好ましい。繊維構造物２にコーティング処理が施されることで、繊維構造物２の親水性が向上する。これにより、後述する複合断熱材１の製造工程において、繊維構造物２の繊維２ａ間に多孔質ゲル３の原料水溶液が浸み込みやすくなる。また、繊維構造物２の繊維２ａと多孔質ゲル３との密着性が向上し、繊維構造物２から多孔質ゲル３が脱離することが抑制される。 Furthermore, it is preferable that the fiber structure 2 is subjected to coating treatment such as plasma treatment and corona treatment or coating treatment with a silane coupling agent. By subjecting the fiber structure 2 to a coating process, the hydrophilicity of the fiber structure 2 is improved. Thereby, in the manufacturing process of the composite heat insulating material 1 mentioned later, the raw material aqueous solution of the porous gel 3 becomes easy to permeate between the fibers 2a of the fiber structure 2. As shown in FIG. Further, the adhesion between the fibers 2a of the fiber structure 2 and the porous gel 3 is improved, and the detachment of the porous gel 3 from the fiber structure 2 is suppressed.
（多孔質ゲル）
　本実施の形態の多孔質ゲル３は、二酸化ケイ素が立体的に繋がることで形成されたシリカ骨格を有するゲルを溶媒置換により乾燥させることで得られた所謂キセロゲルである。多孔質ゲル３には、シリカ骨格の間に複数の空隙（孔）が形成されている。
　詳細については後述するが、本実施の形態の多孔質ゲル３は、アルコキシシラン化合物としてトリアルコキシシラン化合物およびテトラアルコキシシラン化合物を重合させてゲルを生成し、これを溶媒置換により乾燥させることで得られる。これにより、多孔質ゲル３のシリカ骨格には、３つの架橋点を有するトリアルコキシシラン化合物に由来する骨格構造と、４つの架橋点を有するテトラアルコキシシラン化合物に由来する骨格構造とが存在する。 (Porous gel)
The porous gel 3 of the present embodiment is a so-called xerogel obtained by drying a gel having a silica skeleton formed by sterically linking silicon dioxide by solvent substitution. In the porous gel 3, a plurality of voids (pores) are formed between silica skeletons.
Although details will be described later, the porous gel 3 of this embodiment is obtained by polymerizing a trialkoxysilane compound and a tetraalkoxysilane compound as an alkoxysilane compound to form a gel, and drying the gel by solvent substitution. Be As a result, in the silica skeleton of the porous gel 3, a skeleton structure derived from a trialkoxysilane compound having three crosslinking points and a skeleton structure derived from a tetraalkoxysilane compound having four crosslinking points are present.
　多孔質ゲル３の空隙の大きさは、大気圧下での気体分子の平均自由行程以下となっている。これにより、本実施の形態の複合断熱材１では、多孔質ゲル３によって空気の対流による熱伝導を抑制し、断熱性を維持している。 The size of the pores of the porous gel 3 is equal to or less than the mean free path of gas molecules under atmospheric pressure. Thereby, in the composite heat insulating material 1 of the present embodiment, the porous gel 3 suppresses the heat conduction due to the convection of air and maintains the heat insulating property.
　多孔質ゲル３は、ＢＥＴ法による比表面積が、５５０ｍ2／ｇ以上７００ｍ2／ｇ以下の範囲であることが好ましい。多孔質ゲル３のＢＥＴ法による比表面積が５５０ｍ2／ｇ未満である場合には、多孔質ゲル３においてシリカ骨格を構成する固体成分が多くなる。このため、シリカ骨格を介した熱伝導が多くなり、複合断熱材１の熱伝導率が大きくなりやすい。一方、多孔質ゲル３のＢＥＴ法による比表面積が７００ｍ2／ｇよりも大きい場合には、多孔質ゲル３においてシリカ骨格を構成する固体成分が少なくなる。このため、複合断熱材１の製造過程や使用時に、多孔質ゲル３の空隙がつぶれやすくなり、複合断熱材１の熱伝導率が大きくなりやすい。 The porous gel 3 preferably has a specific surface area by BET method in the range of 550 m 2 / g to 700 m 2 / g. When the specific surface area of the porous gel 3 according to the BET method is less than 550 m 2 / g, the solid component constituting the silica skeleton in the porous gel 3 is increased. For this reason, the heat conduction through the silica skeleton increases, and the heat conductivity of the composite heat insulating material 1 tends to increase. On the other hand, when the specific surface area of the porous gel 3 by BET method is larger than 700 m 2 / g, the solid component constituting the silica skeleton in the porous gel 3 is reduced. For this reason, the void of the porous gel 3 is easily crushed during the manufacturing process or use of the composite heat insulating material 1, and the thermal conductivity of the composite heat insulating material 1 tends to be large.
　また、多孔質ゲル３は、ＢＪＨ法による細孔容積が、３．０ｃｍ3／ｇ以上４．０ｃｍ3／ｇ以下の範囲であることが好ましい。多孔質ゲル３のＢＪＨ法による細孔容積が３．０ｃｍ3／ｇ未満である場合には、多孔質ゲル３においてシリカ骨格を構成する固体成分が多くなる。このため、シリカ骨格を介した熱伝導が多くなり、複合断熱材１の熱伝導率が大きくなりやすい。一方、多孔質ゲル３のＢＪＨ法による細孔容積が４．０ｃｍ3／ｇよりも大きい場合には、多孔質ゲル３においてシリカ骨格を構成する固体成分が少なくなる。このため、複合断熱材１の製造過程や使用時に、多孔質ゲル３の空隙がつぶれやすくなり、複合断熱材１の熱伝導率が大きくなりやすい。 The porous gel 3, the pore volume by the BJH method is preferably in the range of less 3.0 cm 3 / g or more 4.0 cm 3 / g. When the pore volume of the porous gel 3 by the BJH method is less than 3.0 cm 3 / g, the solid component constituting the silica skeleton in the porous gel 3 is increased. For this reason, the heat conduction through the silica skeleton increases, and the heat conductivity of the composite heat insulating material 1 tends to increase. On the other hand, when the pore volume of the porous gel 3 by the BJH method is larger than 4.0 cm 3 / g, the solid component constituting the silica skeleton in the porous gel 3 is reduced. For this reason, the void of the porous gel 3 is easily crushed during the manufacturing process or use of the composite heat insulating material 1, and the thermal conductivity of the composite heat insulating material 1 tends to be large.
　本実施の形態の複合断熱材１の熱伝導率は、１２．５ｍＷ／ｍＫ以上１４．０ｍＷ／ｍＫ以下の範囲である。これにより、本実施の形態の複合断熱材１は、例えば熱伝導率が２０ｍＷ／ｍＫ程度の硬質ウレタンフォームや熱伝導率が３０～４０ｍＷ／ｍＫ程度の発泡スチロールからなる断熱材と比較して、優れた断熱効率を有する。 The thermal conductivity of the composite heat insulating material 1 of the present embodiment is in the range of not less than 12.5 mW / mK and not more than 14.0 mW / mK. Thereby, the composite heat insulating material 1 of the present embodiment is superior to, for example, a heat insulating material composed of a hard urethane foam having a thermal conductivity of about 20 mW / mK or a foamed polystyrene having a thermal conductivity of about 30 to 40 mW / mK. Have adiabatic efficiency.
［複合断熱材の製造方法］
　続いて、本実施の形態が適用される複合断熱材１の製造方法について説明する。複合断熱材１は、まず、原料水溶液を調整し、原料水溶液に繊維構造物２を浸漬する。そして、原料水溶液を加熱して、後述するアルコキシシラン化合物を重合させることで、繊維構造物２の繊維２ａ間にゲルを形成する。続いて、ゲルが形成された繊維構造物２をメタノールで洗浄した後、ヘキサンを用いて溶媒置換する。その後、予め定めた温度に加熱することで溶媒が完全に揮発するまで乾燥し、繊維構造物２に多孔質ゲル３が複合化された複合断熱材１を得る。
　以下、複合断熱材１の製造方法における各工程について、順に説明する。 [Method of manufacturing composite heat insulating material]
Then, the manufacturing method of the composite heat insulating material 1 to which this Embodiment is applied is demonstrated. First, the composite heat insulating material 1 prepares a raw material aqueous solution, and immerses the fiber structure 2 in the raw material aqueous solution. And a raw material aqueous solution is heated and a gel is formed between the fibers 2a of the fiber structure 2 by polymerizing the alkoxysilane compound mentioned later. Subsequently, the fiber structure 2 in which the gel is formed is washed with methanol and then solvent-replaced with hexane. Thereafter, by heating to a predetermined temperature, drying is performed until the solvent is completely evaporated, and the composite heat insulating material 1 in which the porous gel 3 is complexed to the fiber structure 2 is obtained.
Hereinafter, each process in the manufacturing method of the composite heat insulating material 1 is demonstrated in order.
（原料水溶液調整工程）
　ゲル原料であるアルコキシシラン化合物、界面活性剤、水等を予め定められた割合で含有する原料水溶液を調整する。具体的には、酢酸等の酸触媒で酸性に調整された水溶液に対して、アルコキシシラン化合物、界面活性剤等を添加し、溶解させることで、アルコキシシラン化合物が加水分解してゾル化した原料水溶液を調整する。ここで、本実施の形態の複合断熱材１の製造に用いる原料水溶液には、メタノールやエタノール等のアルコールは添加しない。 (Raw material aqueous solution adjustment process)
A raw material aqueous solution containing an alkoxysilane compound which is a gel raw material, a surfactant, water and the like in a predetermined ratio is prepared. Specifically, an alkoxysilane compound, a surfactant, and the like are added to an aqueous solution adjusted to be acidic with an acid catalyst such as acetic acid, and dissolved to dissolve the alkoxysilane compound so that it is solified. Prepare the aqueous solution. Here, an alcohol such as methanol or ethanol is not added to the raw material aqueous solution used for producing the composite heat insulating material 1 of the present embodiment.
　本実施の形態では、ゲル原料であるアルコキシシラン化合物として、トリアルコキシシラン化合物とテトラアルコキシシラン化合物とを、テトラアルコキシシラン化合物がアルコキシシラン化合物の総体積に対して４％以上１０％以下の範囲となるように配合した混合物を用いる。 In this embodiment, a trialkoxysilane compound and a tetraalkoxysilane compound are used as an alkoxysilane compound which is a gel material, and the tetraalkoxysilane compound is in a range of 4% to 10% with respect to the total volume of the alkoxysilane compound. Use a mixture formulated to be
　アルコキシシラン化合物におけるテトラアルコキシシラン化合物の配合量が４％未満である場合には、多孔質ゲル３における骨格構造の強度が低下して、空隙がつぶれやすくなる。この場合、複合断熱材１の熱伝導率が大きくなりやすい。
　一方、アルコキシシラン化合物におけるテトラアルコキシシラン化合物の配合量が１０％よりも多い場合には、後述するゲル化の工程において凝集物が生成されるおそれがある。この場合、多孔質ゲル３における骨格構造が不均一になる場合があり、複合断熱材１の熱伝導率が大きくなりやすい。 When the blending amount of the tetraalkoxysilane compound in the alkoxysilane compound is less than 4%, the strength of the skeleton structure in the porous gel 3 is reduced, and the voids are easily collapsed. In this case, the thermal conductivity of the composite heat insulating material 1 tends to be large.
On the other hand, if the blending amount of the tetraalkoxysilane compound in the alkoxysilane compound is more than 10%, there is a possibility that an aggregate is formed in the step of gelation described later. In this case, the skeletal structure of the porous gel 3 may be uneven, and the thermal conductivity of the composite heat insulating material 1 tends to be large.
　トリアルコキシシラン化合物としては、トリメトキシシラン、トリエトキシシラン、モノメチルトリメトキシシラン、モノメチルトリエトキシシラン、エチルトリメトキシシラン、エチルトリエトキシシラン、プロピルトリメトキシシラン、プロピルトリエトキシシラン等が挙げられる。これらの中でも、トリメトキシシランまたはトリエトキシシランを用いることが好ましく、トリメトキシシランを用いることがより好ましい。 Examples of trialkoxysilane compounds include trimethoxysilane, triethoxysilane, monomethyltrimethoxysilane, monomethyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane and the like. Among these, it is preferable to use trimethoxysilane or triethoxysilane, and it is more preferable to use trimethoxysilane.
　テトラアルコキシシラン化合物としては、テトラメトキシシラン、テトラエトキシシラン、テトラｎ－プロポキシシラン、テトラｎ－ブトキシシラン等が挙げられる。これらの中でも、テトラメトキシシランまたはテトラエトキシシランを用いることが好ましく、テトラメトキシシランを用いることがより好ましい。 Examples of tetraalkoxysilane compounds include tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, and tetra n-butoxysilane. Among these, it is preferable to use tetramethoxysilane or tetraethoxysilane, and it is more preferable to use tetramethoxysilane.
　なお、アルコキシシラン化合物には、トリアルコキシシラン化合物およびテトラアルコキシシラン化合物の他、ジアルコキシシラン化合物やモノアルコキシシラン化合物を含んでいてもよい。 The alkoxysilane compound may contain a dialkoxysilane compound or a monoalkoxysilane compound in addition to the trialkoxysilane compound and the tetraalkoxysilane compound.
　界面活性剤は、アルコキシシラン化合物を重合反応させゲル化させる過程において、原料水溶液におけるトリアルコキシシラン化合物およびテトラアルコキシシラン化合物の分散性を改善するために添加される。言い換えると、界面活性剤を用いることで、原料水溶液中で、アルコキシシラン化合物の適当な相分離構造が形成される。これにより、多孔質ゲル３の骨格構造が均一となり、多孔質ゲル３に微細な空隙が均一に形成されるようになる。 The surfactant is added in order to improve the dispersibility of the trialkoxysilane compound and the tetraalkoxysilane compound in the raw material aqueous solution in the process of causing the alkoxysilane compound to undergo polymerization reaction and gelation. In other words, by using the surfactant, an appropriate phase separation structure of the alkoxysilane compound is formed in the aqueous solution of the raw material. As a result, the skeletal structure of the porous gel 3 becomes uniform, and fine voids are uniformly formed in the porous gel 3.
　界面活性剤としては、特に限定されるものではないが、例えば、カチオン性界面活性剤、アニオン性界面活性剤、両イオン性界面活性剤から選ばれる少なくとも一種を用いることができる。これらの中でも、カチオン性界面活性剤を用いることが好ましく、特に臭化ヘキサデシルトリメチルアンモニウムまたは塩化ヘキサデシルトリメチルアンモニウムを用いることがより好ましい。
　界面活性剤として臭化ヘキサデシルトリメチルアンモニウムまたは塩化ヘキサデシルトリメチルアンモニウムを用いることで、骨格構造および空隙が均一に形成された多孔質ゲル３を得ることができる。 The surfactant is not particularly limited, and for example, at least one selected from cationic surfactants, anionic surfactants, and amphoteric surfactants can be used. Among these, it is preferable to use a cationic surfactant, and in particular, it is more preferable to use hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride.
By using hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride as a surfactant, the porous gel 3 in which the skeletal structure and the voids are uniformly formed can be obtained.
　原料水溶液に対する界面活性剤の添加量は、アルコキシシラン化合物や界面活性剤の種類等によっても異なるが、例えば、アルコキシシラン化合物の体積１０００ｍＬ（１０００ｃｍ3）あたり８０ｇ以上８６ｇ以下の範囲とすることができる。 The amount of surfactant added to the raw material aqueous solution varies depending on the type of alkoxysilane compound and surfactant, but can be, for example, in the range of 80 g to 86 g per 1000 mL (1000 cm 3 ) volume of alkoxysilane compound. .
　原料水溶液には、ｐＨを酸性に調整し、アルコキシシラン化合物の加水分解を促進するための酸触媒を添加することが好ましい。酸触媒としては、酢酸、塩酸、硝酸、硫酸、亜硫酸、リン酸、臭酸、シュウ酸、コハク酸等が挙げられる。これらの中でも、酢酸を用いることが好ましい。 It is preferable to adjust pH to acidity and to add an acid catalyst for promoting hydrolysis of the alkoxysilane compound to the raw material aqueous solution. As the acid catalyst, acetic acid, hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, phosphoric acid, bromic acid, oxalic acid, succinic acid and the like can be mentioned. Among these, it is preferable to use acetic acid.
　ここで、詳細については後述するが、本実施の形態の複合断熱材１の製造方法では、アルコキシシラン化合物のゲル化工程において、原料水溶液のｐＨを上昇させることで、重合反応を促進させる。本実施の形態では、原料水溶液に尿素を添加しておき、後述する重合過程において加熱によりアンモニアが発生するようにして、原料水溶液のｐＨを上昇させる。
　なお、後述するゲル化工程において、原料水溶液に塩基触媒を添加することで原料水溶液のｐＨを上昇させてもよい。塩基触媒としては、水酸化リチウム、水酸化ナトリウム、水酸化カリウム、水酸化セシウム等の水酸化アルカリ金属や、水酸化アンモニウム、フッ化アンモニウム、臭化アンモニウム等のアンモニウム化合物等が挙げられる。 Here, although the details will be described later, in the method of manufacturing the composite heat insulating material 1 of the present embodiment, the polymerization reaction is promoted by raising the pH of the raw material aqueous solution in the gelation step of the alkoxysilane compound. In the present embodiment, urea is added to the aqueous solution of raw material, ammonia is generated by heating in the polymerization process described later, and the pH of the aqueous solution of raw material is raised.
In addition, in the gelation process mentioned later, you may raise pH of raw material aqueous solution by adding a base catalyst to raw material aqueous solution. Examples of the base catalyst include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and cesium hydroxide, and ammonium compounds such as ammonium hydroxide, ammonium fluoride and ammonium bromide.
　上述したように、本実施の形態の複合断熱材１の製造に用いる原料水溶液は、アルコールを含んでいない。ここで、アルコキシシラン化合物を用いてゲルを生成するための原料水溶液には、生成されるゲルの分散性を改善するために、アルコキシシラン化合物を溶解し且つ水との相溶性を有するアルコールを添加することが一般である。これに対し、本実施の形態では、トリアルコキシシラン化合物とテトラアルコキシシラン化合物とを上記の割合で配合したアルコキシシラン化合物を用い、且つ、界面活性剤を添加することで、原料水溶液に対するアルコールの添加を不要としている。
　原料水溶液にアルコールを実質含まないことで、ゲル原料中のアルコキシシラン化合物の加水分解によるゾルの生成時間を短縮化することができる。なお、本実施の形態において、原料水溶液がアルコールを実質含まないとは、原料水溶液に対して溶媒としてアルコールを積極的には添加していないことを意味する。 As mentioned above, the raw material aqueous solution used for manufacture of the composite heat insulating material 1 of this Embodiment does not contain alcohol. Here, in order to improve the dispersibility of the gel to be produced, an alcohol which dissolves the alkoxysilane compound and has compatibility with water is added to the raw material aqueous solution for producing the gel using the alkoxysilane compound. It is common to do. On the other hand, in the present embodiment, by using an alkoxysilane compound in which a trialkoxysilane compound and a tetraalkoxysilane compound are blended in the above ratio, and adding a surfactant, the addition of alcohol to the raw material aqueous solution is performed. Is unnecessary.
By containing substantially no alcohol in the raw material aqueous solution, it is possible to shorten the formation time of the sol by hydrolysis of the alkoxysilane compound in the gel raw material. In the present embodiment, the fact that the raw material aqueous solution does not substantially contain alcohol means that alcohol is not positively added as a solvent to the raw material aqueous solution.
（含浸工程）
　続いて、調整した原料水溶液に、予めコーティング処理やバインダ樹脂による融着等の処理を施した繊維構造物２を浸漬する。この際、原料水溶液に対して繊維構造物２が完全に浸かるように浸漬する。これにより、繊維構造物２の繊維２ａに原料水溶液が行き渡るようになる。 (Impregnation process)
Subsequently, the fiber structure 2 which has been subjected to a treatment such as a coating treatment or a fusion with a binder resin in advance is immersed in the adjusted raw material aqueous solution. At this time, the fiber structure 2 is immersed in the raw material aqueous solution so as to be completely immersed. As a result, the raw material aqueous solution spreads over the fibers 2 a of the fiber structure 2.
（ゲル化工程）
　続いて、繊維構造物２を浸漬した原料水溶液を予め定めた温度に加熱することで、原料水溶液に含まれるアルコキシシラン化合物を重合反応させ、ゲル化させる。付言すると、原料水溶液を加熱することで、原料水溶液に含まれる尿素からアンモニアが発生し、原料水溶液のｐＨが上昇する。これにより、アルコキシシラン化合物の重合反応が促進され、トリアルコキシシラン化合物およびテトラアルコキシシラン化合物が重合し、繊維構造物２の繊維２ａ間にゲルが生成される。なお、以下の説明において、繊維２ａ間にゲルが生成された繊維構造物２を、ゲル生成繊維構造物と称する場合がある。 (Gelation process)
Subsequently, the raw material aqueous solution in which the fiber structure 2 is immersed is heated to a predetermined temperature to cause the alkoxysilane compound contained in the raw material aqueous solution to undergo a polymerization reaction to gelate. In addition, by heating the aqueous solution of raw material, ammonia is generated from urea contained in the aqueous solution of raw material, and the pH of the aqueous solution of raw material rises. As a result, the polymerization reaction of the alkoxysilane compound is promoted, the trialkoxysilane compound and the tetraalkoxysilane compound are polymerized, and a gel is formed between the fibers 2 a of the fiber structure 2. In addition, in the following description, the fiber structure 2 in which the gel was produced | generated between the fibers 2a may be called a gel production fiber structure.
　原料水溶液の加熱温度は、例えば、６０℃以上８０℃以下の範囲とすることができる。
　また、原料水溶液を加熱してゲル化する時間としては、加熱温度等によっても異なるが、例えば、２４時間以上１２０時間以下の範囲とすることができる。 The heating temperature of the raw material aqueous solution can be, for example, in the range of 60 ° C. or more and 80 ° C. or less.
In addition, the time for heating and gelling the raw material aqueous solution may vary depending on the heating temperature and the like, but can be, for example, in the range of 24 hours to 120 hours.
　また、原料水溶液の加熱によるゲル化を行った後、加熱を継続して養生（エイジング）することが好ましい。養生を行うことで、ゲルを構成するシリカ骨格の結合を強化することができ、後述する乾燥工程での空隙のつぶれ等を抑制することができる。
　養生温度は、例えば、６０℃以上８０℃以下の範囲とすることができる。また、養生時間は、養生温度等によっても異なるが、例えば、５時間以上７２時間以下の範囲とすることができる。なお、養生は、ゲル生成繊維構造物を原料水溶液に継続して浸漬したまま行ってもよく、ゲル生成繊維構造物を原料水溶液から取り出して純水等に浸漬して行ってもよい。 Moreover, it is preferable to continue heating and to perform aging (aging) after gelation by heating the raw material aqueous solution. By curing, it is possible to strengthen the bond of the silica skeleton that constitutes the gel, and to suppress the collapse of voids or the like in the later-described drying step.
The curing temperature can be, for example, in the range of 60 ° C. or more and 80 ° C. or less. Moreover, although curing time changes with curing temperature etc., it can be made into the range of 5 hours or more and 72 hours or less, for example. In addition, curing may be performed while the gel-forming fiber structure is continuously immersed in the raw material aqueous solution, or the gel-forming fiber structure may be removed from the raw material aqueous solution and immersed in pure water or the like.
（洗浄工程）
　続いて、ゲル生成繊維構造物をアルコールで洗浄する。具体的には、ゲル生成繊維構造物のゲルの空隙内に残存する界面活性剤や未反応のアルコキシシラン化合物、水等をアルコールで洗浄することにより取り除く。
　洗浄に用いるアルコールとしては、アルコキシシラン化合物や水、界面活性剤との親和性が高く、また後述する溶媒置換に用いるヘキサンとの親和性が高いものが用いられる。このようなアルコールとして具体的には、メタノール、エタノール、イソプロピルアルコール等が挙げられる。これらの中でも、メタノールを用いることが好ましい。 (Washing process)
Subsequently, the gel-forming fiber structure is washed with alcohol. Specifically, the surfactant remaining in the pores of the gel of the gel-formed fiber structure, the unreacted alkoxysilane compound, water and the like are removed by washing with alcohol.
As the alcohol used for the washing, those having high affinity to the alkoxysilane compound, water, surfactant, and high affinity to hexane used for solvent substitution described later are used. Specific examples of such alcohols include methanol, ethanol, isopropyl alcohol and the like. Among these, it is preferable to use methanol.
　ここで、ゲル生成繊維構造物のゲルに水や界面活性剤等が残存している場合、後述する乾燥工程において水や界面活性剤の減少に伴ってゲルの骨格構造が収縮する。この場合、得られる多孔質ゲル３の比表面積や細孔容積が減少し、複合断熱材１による断熱効率が低下するおそれがある。
　これに対し、本実施の形態では、溶媒置換する前にゲル生成繊維構造物をアルコールで洗浄することで、ゲル内に水や界面活性剤が残存することが抑制される。 Here, when water, surfactant, and the like remain in the gel of the gel-forming fiber structure, the skeletal structure of the gel shrinks as the water and surfactant decrease in the drying step described later. In this case, the specific surface area and pore volume of the obtained porous gel 3 may be reduced, and the heat insulation efficiency of the composite heat insulating material 1 may be reduced.
On the other hand, in the present embodiment, by washing the gel-forming fiber structure with alcohol before solvent substitution, it is possible to suppress the water and the surfactant from remaining in the gel.
（溶媒置換工程）
　続いて、ゲル生成繊維構造物におけるゲルの空隙内に残存するアルコールを、ヘキサンで置換する。
　ヘキサンは、洗浄工程に用いるアルコールとの親和性を有し、且つ水や洗浄工程に用いるアルコールと比較して表面張力が小さい溶媒である。したがって、ゲル生成繊維構造物におけるゲルの空隙内をヘキサンで置換することで、後述する乾燥工程において、溶媒の減少に伴うゲルの骨格構造の収縮が抑制される。この結果、多孔質ゲル３の比表面積や細孔容積の減少が抑制され、複合断熱材１による断熱効率の低下が抑制される。 (Solvent substitution process)
Subsequently, the alcohol remaining in the pores of the gel in the gel-formed fiber structure is replaced with hexane.
Hexane is a solvent that has an affinity to the alcohol used in the washing step and has a smaller surface tension as compared to water or an alcohol used in the washing step. Therefore, by substituting the inside of the gel voids in the gel-forming fiber structure with hexane, the shrinkage of the gel skeleton structure accompanying the reduction of the solvent is suppressed in the drying step described later. As a result, the decrease in the specific surface area and the pore volume of the porous gel 3 is suppressed, and the decrease in the adiabatic efficiency by the composite heat insulating material 1 is suppressed.
（乾燥工程）
　続いて、ヘキサンで溶媒置換したゲル生成繊維構造物を予め定めた温度で加熱してヘキサンを完全に取り除くことで、繊維構造物２の繊維２ａ間に生成されたゲルを乾燥し、多孔質ゲル３を生成する。
　本実施の形態では、ゲル生成繊維構造物の乾燥工程は、超臨界乾燥法のように高圧環境で行う必要はなく、常圧環境または減圧環境で行うことができる。 (Drying process)
Subsequently, the gel produced between the fibers 2a of the fiber structure 2 is dried by heating the solvent-replaced gel-formed fiber structure with hexane at a predetermined temperature to completely remove the hexane, and the porous gel is obtained. Generate 3
In the present embodiment, the step of drying the gel-forming fiber structure does not have to be performed in a high pressure environment as in the supercritical drying method, and can be performed in a normal pressure environment or a reduced pressure environment.
　本実施の形態では、上述したように、ゲル原料として、トリアルコキシシラン化合物とテトラアルコキシシラン化合物とを所定の割合で含むアルコキシシラン化合物を用いている。また、原料水溶液に界面活性剤を添加している。これにより、ゲル生成繊維構造物のゲルについて、均一で強固な骨格構造が形成されている。さらに、上述したように、溶媒置換工程においてゲルの空隙内を表面張力の小さいヘキサンにて置換している。
　これにより、常圧環境または減圧環境で乾燥工程を行った場合であっても、溶媒の減少に伴う骨格構造の収縮や破裂が抑制される。この結果、微細な空隙が形成された多孔質ゲル３が形成され、複合断熱材１の熱伝導率を低くすることができる。 In the present embodiment, as described above, an alkoxysilane compound containing a trialkoxysilane compound and a tetraalkoxysilane compound in a predetermined ratio is used as a gel material. In addition, a surfactant is added to the raw material aqueous solution. As a result, a uniform and strong skeletal structure is formed for the gel of the gel-forming fiber structure. Furthermore, as described above, in the solvent replacement step, the inside of the pores of the gel is replaced with hexane having a small surface tension.
As a result, even when the drying step is performed in a normal pressure environment or a reduced pressure environment, the contraction and rupture of the skeletal structure caused by the decrease in the solvent can be suppressed. As a result, the porous gel 3 in which the fine space | gap was formed is formed, and the heat conductivity of the composite heat insulating material 1 can be made low.
　以上の工程により、図１に示したように、繊維構造物２の繊維２ａ間に多孔質ゲル３が形成された複合断熱材１を得ることができる。 By the above steps, as shown in FIG. 1, the composite heat insulating material 1 in which the porous gel 3 is formed between the fibers 2 a of the fiber structure 2 can be obtained.
　以上説明したように、本実施の形態の複合断熱材１の製造方法では、ヘキサンによる溶媒置換を行った後、溶媒を乾燥させることで、超臨界乾燥法を行わずに多孔質ゲル３を作製している。これにより、多孔質ゲル３を作製する場合に超臨界乾燥法を採用する場合と比較して、複合断熱材１の製造に要するコストや手間、時間等を低減することができる。 As explained above, in the manufacturing method of the composite heat insulating material 1 of the present embodiment, after the solvent substitution with hexane is performed, the solvent is dried to manufacture the porous gel 3 without performing the supercritical drying method. doing. Thereby, compared with the case where a supercritical drying method is adopted when producing porous gel 3, cost, effort, time, etc. which manufacture of composite heat insulating material 1 requires can be reduced.
　また、本実施の形態では、多孔質ゲル３のゲル原料として、トリアルコキシシラン化合物とテトラアルコキシシラン化合物とを所定の割合で含むアルコキシシラン化合物を用いている。さらに、原料水溶液に、アルコキシシラン化合物に加えて界面活性剤を添加している。さらにまた、原料水溶液には、アルコールを添加していない。
　これにより、原料水溶液中で適当なアルコキシシラン化合物の適当な相分離構造が形成され、微細な空隙が均一に形成された多孔質ゲル３を得ることができる。そして、繊維構造物２と多孔質ゲル３が複合化された複合断熱材１の断熱効率を向上させることができる。 Further, in the present embodiment, an alkoxysilane compound containing a trialkoxysilane compound and a tetraalkoxysilane compound in a predetermined ratio is used as the gel material of the porous gel 3. Furthermore, in addition to the alkoxysilane compound, a surfactant is added to the raw material aqueous solution. Furthermore, alcohol is not added to the raw material aqueous solution.
As a result, an appropriate phase separation structure of an appropriate alkoxysilane compound is formed in the aqueous solution of the raw material, and a porous gel 3 in which fine voids are uniformly formed can be obtained. And the heat insulation efficiency of the composite heat insulating material 1 with which the fiber structure 2 and the porous gel 3 were compounded can be improved.
［複合断熱材の用途］
　本実施の形態の複合断熱材は、保冷や保温等の断熱が必要となる製品に採用することができる。このような製品としては、例えば、冷蔵庫、冷凍庫、ショーケース、洗濯乾燥機、自動販売機、建築用壁等が挙げられるが、これらに限定されるものではない。 [Application of composite heat insulating material]
The composite heat insulating material of the present embodiment can be employed for products that require heat insulation such as cold insulation and heat retention. Examples of such products include, but are not limited to, refrigerators, freezers, showcases, washing and drying machines, vending machines, construction walls, and the like.
　続いて、本発明を実施例に基づいてより詳細に説明する。なお、本発明は、以下の実施例に限定されるものではない。
［実施例１］
（原料水溶液調整工程）
　５ｍＭ酢酸水溶液１０００ｍＬに対して、界面活性剤として臭化ヘキサデシルトリメチルアンモニウム４０ｇを添加し攪拌し、さらに尿素３００ｇを添加して１時間攪拌した。この水溶液に対して、ゲル原料として、トリアルコキシシラン化合物としてトリメトキシシラン４７５ｍＬと、テトラアルコキシシラン化合物としてテトラメトキシシラン２５ｍＬとを投入し、３０分攪拌した。これにより、アルコキシシラン化合物が加水分解された透明な原料水溶液を得た。なお、この原料水溶液においてアルコキシシラン化合物の総体積におけるテトラアルコキシシラン化合物（テトラメトキシシラン）の含有量は、５％である。また、この原料水溶液には、アルコールは実質含まれていない。 The invention will now be described in more detail on the basis of examples. The present invention is not limited to the following examples.
Example 1
(Raw material aqueous solution adjustment process)
To 1000 mL of 5 mM aqueous acetic acid solution, 40 g of hexadecyltrimethylammonium bromide as a surfactant was added and stirred, and further 300 g of urea was added and stirred for 1 hour. Into this aqueous solution, 475 mL of trimethoxysilane as a trialkoxysilane compound and 25 mL of tetramethoxysilane as a tetraalkoxysilane compound were added as gel raw materials and stirred for 30 minutes. Thereby, the transparent raw material aqueous solution in which the alkoxysilane compound was hydrolyzed was obtained. The content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in the aqueous solution of the raw material is 5%. In addition, the raw material aqueous solution contains substantially no alcohol.
（含浸工程、ゲル化工程）
　続いて、原料水溶液に対して、ＰＥＴ製の不織布（１４．５ｃｍ角）１４．６ｇを重ねて糸で縫い合わせることで形成した繊維構造物２を、上記の原料水溶液に完全に浸る状態で浸漬した。
　次いで、６０℃のオーブンに４日間静置し、繊維構造物２の繊維２ａ間にゲルを作製した。その後、繊維２ａ間にゲルが形成された繊維構造物２（ゲル生成繊維構造物）を原料水溶液から取り出し、純水に完全に浸かる状態で浸漬して、６０℃の温度条件で１日間（２４時間）養生した。 (Impregnation process, gelation process)
Subsequently, a fiber structure 2 formed by overlapping 14.6 g of a PET non-woven fabric (14.5 cm square) with a raw material aqueous solution and sewing them together with a yarn was immersed in the above raw material aqueous solution in a completely immersed state .
Then, it was left to stand in an oven at 60 ° C. for 4 days to make a gel between the fibers 2 a of the fiber structure 2. Thereafter, the fiber structure 2 (gel-forming fiber structure) in which the gel is formed between the fibers 2a is taken out from the raw material aqueous solution, and immersed in pure water in a completely immersed state for one day at 60.degree. Time) healed.
（洗浄工程、溶媒置換工程）
　繊維２ａ間にゲルが形成された繊維構造物２（ゲル生成繊維構造物）を純水から取り出し、メタノールを用いて洗浄した。
　続いて、洗浄後のゲル生成繊維構造物をヘキサンに完全に浸かる状態で浸漬し、ゲルの空隙内をヘキサンで置換した。 (Washing process, solvent substitution process)
The fiber structure 2 (gel-forming fiber structure) in which the gel was formed between the fibers 2a was taken out from the pure water and washed with methanol.
Subsequently, the gel-formed fiber structure after washing was immersed in hexane while completely immersed, and the inside of the pores of the gel was replaced with hexane.
（乾燥工程）
　ゲルの空隙内をヘキサンで置換したゲル生成繊維構造物を４０℃のホットプレートに配置し、溶媒が完全に揮発するまで乾燥して多孔質ゲル３を形成し、複合断熱材１を得た。 (Drying process)
The gel-formed fiber structure in which the gel voids were replaced with hexane was placed on a hot plate at 40 ° C., and dried until the solvent was completely evaporated to form a porous gel 3 to obtain a composite heat insulating material 1.
（評価）
　得られた複合断熱材１についてＮＥＴＺＳＣＨ社製ＨＦＭ４３６／３を用いて測定した熱伝導率は、１３．５ｍＷ／ｍＫであった。
　また、得られた複合断熱材１について、Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＡＳＡＰ２０１０を用いて測定したＢＥＴ法による比表面積は６８０ｍ2／ｇであり、ＢＪＨ法による細孔容積は３．６ｃｍ3／ｇであった。
　さらにまた、得られた複合断熱材１について、石英の密度から算出したゲルの空隙率は９５％であった。 (Evaluation)
The thermal conductivity of the obtained composite heat insulating material 1 was measured using a NETZSCH HFM436 / 3, and was 13.5 mW / mK.
Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 680 m < 2 > / g, and the pore volume by BJH method was 3.6 cm < 3 > / g.
Furthermore, the porosity of the gel calculated from the density of quartz was 95% for the composite heat insulating material 1 obtained.
［実施例２］
　原料水溶液に用いるアルコキシシラン化合物として、トリメトキシシラン４６５ｍＬと、テトラメトキシシラン３５ｍＬとを用いた以外は実施例１と同様にして、複合断熱材１を得た。なお、この原料水溶液においてアルコキシシラン化合物の総体積におけるテトラアルコキシシラン化合物（テトラメトキシシラン）の含有量は、７％である。 Example 2
A composite heat insulating material 1 was obtained in the same manner as in Example 1 except that 465 mL of trimethoxysilane and 35 mL of tetramethoxysilane were used as the alkoxysilane compound used for the raw material aqueous solution. The content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in this raw material aqueous solution is 7%.
（評価）
　得られた複合断熱材１についてＮＥＴＺＳＣＨ社製ＨＦＭ４３６／３を用いて測定した熱伝導率は、１４．０ｍＷ／ｍＫであった。
　また、得られた複合断熱材１について、Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＡＳＡＰ２０１０を用いて測定したＢＥＴ法による比表面積は６４０ｍ2／ｇであり、ＢＪＨ法による細孔容積は３．４ｃｍ3／ｇであった。
　さらにまた、得られた複合断熱材１について、石英の密度から算出したゲルの空隙率は、９４．８％であった。 (Evaluation)
The thermal conductivity of the obtained composite heat insulating material 1 was measured using HFM436 / 3 manufactured by NETZSCH, and was 14.0 mW / mK.
Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 640 m < 2 > / g, and the pore volume by BJH method was 3.4 cm < 3 > / g.
Furthermore, the porosity of the gel calculated from the density of quartz was 94.8% for the composite heat insulating material 1 obtained.
［実施例３］
　原料水溶液に用いるアルコキシシラン化合物として、トリメトキシシラン４５０ｍＬと、テトラメトキシシラン５０ｍＬとを用い、界面活性剤として、塩化ヘキサデシルトリメチルアンモニウム４３ｇを用いた以外は実施例１と同様にして、複合断熱材１を得た。なお、この原料水溶液においてアルコキシシラン化合物の総体積におけるテトラアルコキシシラン化合物（テトラメトキシシラン）の含有量は、１０％である。 [Example 3]
A composite heat insulating material was prepared in the same manner as in Example 1, except that 450 mL of trimethoxysilane and 50 mL of tetramethoxysilane were used as the alkoxysilane compound used in the raw material aqueous solution and 43 g of hexadecyltrimethylammonium chloride was used as the surfactant. I got one. The content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in the aqueous solution of the raw material is 10%.
（評価）
　得られた複合断熱材１についてＮＥＴＺＳＣＨ社製ＨＦＭ４３６／３を用いて測定した熱伝導率は、１２．５ｍＷ／ｍＫであった。
　また、得られた複合断熱材１について、Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＡＳＡＰ２０１０を用いて測定したＢＥＴ法による比表面積は７００ｍ2／ｇであり、ＢＪＨ法による細孔容積は４．０ｃｍ3／ｇであった。
　さらにまた、得られた複合断熱材１について、石英の密度から算出したゲルの空隙率は、９５％であった。 (Evaluation)
The thermal conductivity of the obtained composite heat insulating material 1 was measured using HFM436 / 3 manufactured by NETZSCH, and was 12.5 mW / mK.
Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 700 m < 2 > / g, and the pore volume by BJH method was 4.0 cm < 3 > / g.
Furthermore, the porosity of the gel calculated from the density of quartz was 95% for the composite heat insulating material 1 obtained.
［実施例４］
　原料水溶液に用いる界面活性剤として、塩化ヘキサデシルトリメチルアンモニウム４０ｇを用いた以外は実施例１と同様にして、複合断熱材１を得た。 Example 4
A composite heat insulating material 1 was obtained in the same manner as in Example 1 except that 40 g of hexadecyltrimethylammonium chloride was used as a surfactant used for the raw material aqueous solution.
（評価）
　得られた複合断熱材１についてＮＥＴＺＳＣＨ社製ＨＦＭ４３６／３を用いて測定した熱伝導率は、１３．８ｍＷ／ｍＫであった。
　また、得られた複合断熱材１について、Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＡＳＡＰ２０１０を用いて測定したＢＥＴ法による比表面積は６５０ｍ2／ｇであり、ＢＪＨ法による細孔容積は３．５ｃｍ3／ｇであった。
　さらにまた、得られた複合断熱材１について、石英の密度から算出したゲルの空隙率は、９４．８％であった。 (Evaluation)
The thermal conductivity of the obtained composite heat insulating material 1 was measured using HFM436 / 3 manufactured by NETZSCH, and was 13.8 mW / mK.
Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 650 m < 2 > / g, and the pore volume by BJH method was 3.5 cm < 3 > / g.
Furthermore, the porosity of the gel calculated from the density of quartz was 94.8% for the composite heat insulating material 1 obtained.
［実施例５］
　原料水溶液に浸漬する繊維構造物２として、グラスファイバ製の不織布（１４．５ｃｍ角）１４．６ｇを重ねて糸で縫い合わせることで形成した繊維構造物２を用いた以外は実施例１と同様にして、複合断熱材１を得た。 [Example 5]
The same procedure as in Example 1 was repeated, except that 14.6 g of a glass fiber non-woven fabric (14.5 cm square) was overlapped and sewed with yarn as the fiber structure 2 to be immersed in the raw material aqueous solution. The composite heat insulating material 1 was obtained.
（評価）
　得られた複合断熱材１についてＮＥＴＺＳＣＨ社製ＨＦＭ４３６／３を用いて測定した熱伝導率は、１３．５ｍＷ／ｍＫであった。
　また、得られた複合断熱材１について、Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＡＳＡＰ２０１０を用いて測定したＢＥＴ法による比表面積は６８０ｍ2／ｇであり、ＢＪＨ法による細孔容積は３．６ｃｍ3／ｇであった。
　さらにまた、得られた複合断熱材１について、石英の密度から算出したゲルの空隙率は、９５％であった。 (Evaluation)
The thermal conductivity of the obtained composite heat insulating material 1 was measured using a NETZSCH HFM436 / 3, and was 13.5 mW / mK.
Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 680 m < 2 > / g, and the pore volume by BJH method was 3.6 cm < 3 > / g.
Furthermore, the porosity of the gel calculated from the density of quartz was 95% for the composite heat insulating material 1 obtained.
［実施例６］
　原料水溶液に浸漬する繊維構造物２として、グラスファイバ製の不織布（１４．５ｃｍ角）１４．６ｇを重ねて糸で縫い合わせたものに、ＳＡＭＣＯ社製ＰＣ－１０００にて５００Ｗ１８０秒の条件で酸素Ｐｌａｓｍａを照射して形成した繊維構造物２を用いた以外は実施例１と同様にして、複合断熱材を得た。 [Example 6]
As a fiber structure 2 to be immersed in a raw material aqueous solution, 14.6 g of a glass fiber non-woven fabric (14.5 cm square) is overlapped and sewed with a thread, oxygen Plasma under conditions of 500 W for 180 seconds with PC-1000 made by SAMCO. A composite heat insulating material was obtained in the same manner as in Example 1 except that the fiber structure 2 formed by irradiating the same was used.
（評価）
　得られた複合断熱材１についてＮＥＴＺＳＣＨ社製ＨＦＭ４３６／３を用いて測定した熱伝導率は、１２．５ｍＷ／ｍＫであった。
　また、得られた複合断熱材１について、Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＡＳＡＰ２０１０を用いて測定したＢＥＴ法による比表面積は７００ｍ2／ｇであり、ＢＪＨ法による細孔容積は４．０ｃｍ3／ｇであった。
　さらにまた、得られた複合断熱材１について、石英の密度から算出したゲルの空隙率は、９５．２％であった。 (Evaluation)
The thermal conductivity of the obtained composite heat insulating material 1 was measured using HFM436 / 3 manufactured by NETZSCH, and was 12.5 mW / mK.
Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 700 m < 2 > / g, and the pore volume by BJH method was 4.0 cm < 3 > / g.
Furthermore, the porosity of the gel calculated from the density of quartz was 95.2% for the composite heat insulating material 1 obtained.
［比較例１］
　原料水溶液に用いるアルコキシシラン化合物として、トリメトキシシラン４８５ｍＬと、テトラメトキシシラン１５ｍＬとを用いた以外は実施例１と同様にして、複合断熱材１を得た。なお、この原料水溶液においてアルコキシシラン化合物の総体積におけるテトラアルコキシシラン化合物（テトラメトキシシラン）の含有量は、３％である。 Comparative Example 1
A composite heat insulating material 1 was obtained in the same manner as in Example 1 except that 485 mL of trimethoxysilane and 15 mL of tetramethoxysilane were used as the alkoxysilane compound used for the raw material aqueous solution. The content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in the aqueous solution of the raw material is 3%.
（評価）
　得られた複合断熱材１についてＮＥＴＺＳＣＨ製ＨＦＭ４３６／３を用いて測定した熱伝導率は、１６．５ｍＷ／ｍＫであった。
　また、得られた複合断熱材１について、Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＡＳＡＰ２０１０を用いて測定したＢＥＴ法による比表面積は５１０ｍ2／ｇであり、ＢＪＨ法による細孔容積は４．１ｃｍ3／ｇであった。
　さらにまた、得られた複合断熱材１について、石英の密度から算出したゲルの空隙率は、９３．５％であった。 (Evaluation)
The thermal conductivity of the obtained composite heat insulating material 1 measured using NETM SCH HFM436 / 3 was 16.5 mW / mK.
Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 510 m < 2 > / g, and the pore volume by BJH method was 4.1 cm < 3 > / g.
Furthermore, the porosity of the gel calculated from the density of quartz was 93.5% for the composite heat insulating material 1 obtained.
［比較例２］
　原料水溶液に用いるアルコキシシラン化合物として、トリメトキシシラン４００ｍＬと、テトラメトキシシラン１００ｍＬとを用いた以外は実施例１と同様にして、複合断熱材１を得た。なお、この原料水溶液においてアルコキシシラン化合物の総体積におけるテトラアルコキシシラン化合物（テトラメトキシシラン）の含有量は、２０％である。 Comparative Example 2
A composite heat insulating material 1 was obtained in the same manner as in Example 1 except that 400 mL of trimethoxysilane and 100 mL of tetramethoxysilane were used as the alkoxysilane compound used for the raw material aqueous solution. The content of the tetraalkoxysilane compound (tetramethoxysilane) in the total volume of the alkoxysilane compound in the aqueous solution of the raw material is 20%.
（評価）
　得られた複合断熱材１についてＮＥＴＺＳＣＨ製ＨＦＭ４３６／３を用いて測定した熱伝導率は、１６．２ｍＷ／ｍＫであった。
　また、得られた複合断熱材１について、Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＡＳＡＰ２０１０を用いて測定したＢＥＴ法による比表面積は５３０ｍ2／ｇであり、ＢＪＨ法による細孔容積は４．０ｃｍ3／ｇであった。
　さらにまた、得られた複合断熱材１について、石英の密度から算出したゲルの空隙率は、９３．８％であった。 (Evaluation)
The thermal conductivity of the obtained composite heat insulating material 1 measured using NETM SCH HFM436 / 3 was 16.2 mW / mK.
Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 530 m < 2 > / g, and the pore volume by BJH method was 4.0 cm < 3 > / g.
Furthermore, the porosity of the gel calculated from the density of quartz was 93.8% for the composite heat insulating material 1 obtained.
［比較例３］
　原料水溶液に対して、溶媒としてメタノール３００ｍＬ及び水７００ｍＬの混合溶媒を用いた以外は実施例１と同様にして、複合断熱材１を得た。 Comparative Example 3
The composite heat insulating material 1 was obtained like Example 1 except having used the mixed solvent of 300 mL of methanol, and 700 mL of water as a solvent with respect to raw material aqueous solution.
（評価）
　得られた複合断熱材１についてＮＥＴＺＳＣＨ製ＨＦＭ４３６／３を用いて測定した熱伝導率は、２０ｍＷ／ｍＫであった。
　また、得られた複合断熱材１について、Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＡＳＡＰ２０１０を用いて測定したＢＥＴ法による比表面積は４６０ｍ2／ｇであり、ＢＪＨ法による細孔容積は８．０ｃｍ3／ｇであった。
　さらにまた、得られた複合断熱材１について、石英の密度から算出したゲルの空隙率は、９３％であった。 (Evaluation)
The thermal conductivity of the obtained composite heat insulating material 1 was measured using a NETZSCH HFM 436/3, and was 20 mW / mK.
Moreover, about the obtained composite heat insulating material 1, the specific surface area by BET method measured using ASAP2010 by Micromeritics company was 460 m < 2 > / g, and the pore volume by BJH method was 8.0 cm < 3 > / g.
Furthermore, the porosity of the gel calculated from the density of quartz was 93% for the composite heat insulating material 1 obtained.
　実施例１～実施例６の複合断熱材１の構成および評価結果について表１に、比較例１～比較例３の複合断熱材１の構成および評価結果について表２に示す。 Table 1 shows the configuration and evaluation results of the composite heat insulator 1 of Examples 1 to 6, and Table 2 shows the configuration and evaluation results of the composite heat insulator 1 of Comparative Examples 1 to 3.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表１に示すように、ゲル原料であるアルコキシシラン化合物としてトリアルコキシシラン化合物とテトラアルコキシシラン化合物とを、テトラアルコキシシラン化合物がアルコキシシラン化合物の総体積に対して４％以上１０％以下の範囲となるように配合し、原料水溶液に界面活性剤を添加するとともに、原料水溶液が実質アルコールを含まない実施例１～実施例６では、骨格構造および空隙が均一に形成され断熱性能の高い複合断熱材１が得られることが確認された。 As shown in Table 1, a trialkoxysilane compound and a tetraalkoxysilane compound are used as an alkoxysilane compound which is a gel material, and the tetraalkoxysilane compound is in the range of 4% to 10% with respect to the total volume of the alkoxysilane compound. In Examples 1 to 6 in which the raw material aqueous solution contains substantially no alcohol while the surfactant is added to the raw material aqueous solution and the raw material aqueous solution contains substantially no alcohol, a composite heat insulating material having a high thermal insulation performance with uniformly formed skeleton structure and voids. It was confirmed that 1 was obtained.
　これに対し、テトラアルコキシシラン化合物の含有量がアルコキシシラン化合物の総体積に対して４％未満である比較例１、１０％よりも多い比較例２、および原料水溶液にアルコールを含む比較例３では、実施例１～実施例６と比べて複合断熱材１の断熱性能が低下することが確認された。 On the other hand, in Comparative Example 1 where the content of the tetraalkoxysilane compound is less than 4% relative to the total volume of the alkoxysilane compound, Comparative Example 2 more than 10%, and Comparative Example 3 in which the raw material aqueous solution contains alcohol. It has been confirmed that the heat insulating performance of the composite heat insulating material 1 is reduced as compared with Examples 1 to 6.
　また、実施例１～実施例６を互いに比較すると、繊維構造物２（グラスファイバ）に対してプラズマ処理を施した実施例６では、繊維構造物２（グラスファイバ）にプラズマ処理を施していない実施例５と比べて、複合断熱材１の熱伝導率が低下し、断熱性能が高まることが確認された。 Moreover, when Example 1-Example 6 are compared with each other, in Example 6 which performed the plasma processing with respect to the fiber structure 2 (glass fiber), the plasma processing was not performed to the fiber structure 2 (glass fiber) As compared with Example 5, it was confirmed that the thermal conductivity of the composite heat insulating material 1 is lowered and the heat insulating performance is enhanced.
１…複合断熱材、２…繊維構造物、２ａ…繊維、３…多孔質ゲル DESCRIPTION OF SYMBOLS 1 ... Composite thermal insulation, 2 ... fiber structure, 2a.

Claims (11)

  1. 　トリアルコキシシラン化合物とテトラアルコキシシラン化合物とを当該テトラアルコキシシラン化合物がアルコキシシラン化合物の総体積に対して４％以上１０％以下の範囲となるように配合したゲル原料と、水と、界面活性剤とを含み、且つアルコールを実質含まない水溶液を、当該アルコキシシラン化合物を加水分解してゾルを生成させたうえで加熱し、当該アルコキシシラン化合物を重合反応させてゲルを生成し、
    　前記ゲルをアルコールで洗浄し、ヘキサンで溶媒置換した後、乾燥する断熱材の製造方法。     A gel material containing a trialkoxysilane compound and a tetraalkoxysilane compound such that the tetraalkoxysilane compound is in the range of 4% to 10% of the total volume of the alkoxysilane compound, water, and a surfactant And an aqueous solution substantially containing no alcohol, wherein the sol is formed by hydrolyzing the alkoxysilane compound and then heated to polymerize the alkoxysilane compound to form a gel;
    The manufacturing method of the heat insulating material which wash | cleans the said gel by alcohol, carries out solvent substitution by hexane, and is dried.
  2. 　前記水溶液に対して繊維構造物を含浸した後、前記アルコキシシラン化合物を重合反応させて、前記ゲルを包含するゲル生成繊維構造物を生成し、
    　前記ゲル生成繊維構造物をアルコールで洗浄し、ヘキサンで溶媒置換した後、乾燥することを特徴とする請求項１に記載の断熱材の製造方法。     After impregnating the fiber structure with the aqueous solution, the alkoxysilane compound is polymerized to form a gel-forming fiber structure including the gel,
    The method for producing a heat insulating material according to claim 1, wherein the gel-formed fiber structure is washed with alcohol, solvent-replaced with hexane, and then dried.
  3. 　前記繊維構造物として、繊維同士がバインダ樹脂により融着された不織布を、前記水溶液に含浸することを特徴とする請求項２に記載の断熱材の製造方法。 The method for producing a heat insulating material according to claim 2, wherein the aqueous solution is impregnated with a non-woven fabric in which fibers are fused by a binder resin as the fiber structure.
  4. 　プラズマ処理またはシランカップリング剤による表面処理が施された前記繊維構造物を前記水溶液に含浸することを特徴とする請求項２に記載の断熱材の製造方法。 The method according to claim 2, wherein the aqueous solution is impregnated with the fiber structure which has been subjected to plasma treatment or surface treatment with a silane coupling agent.
  5. 　繊維の配向が揃えられた前記繊維構造物を前記水溶液に含浸することを特徴とする請求項２に記載の断熱材の製造方法。 The method according to claim 2, wherein the aqueous solution is impregnated with the fiber structure in which the fiber orientations are aligned.
  6. 　前記界面活性剤として、臭化ヘキサデシルトリメチルアンモニウムまたは塩化ヘキサデシルトリメチルアンモニウムを用いることを特徴とする請求項１に記載の断熱材の製造方法。 The method for producing a heat insulating material according to claim 1, wherein hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride is used as the surfactant.
  7. 　繊維構造物と、
    　前記繊維構造物の内部に保持され、トリアルコキシシラン化合物とテトラアルコキシシラン化合物とを重合させてなるシリカ骨格により形成される多孔質構造を有し、ＢＥＴ法により測定される比表面積が５５０ｍ2／ｇ以上７００ｍ2／ｇ以下の範囲であり、ＢＪＨ法により測定される細孔容積が３．０ｃｍ3／ｇ以上４．０ｃｍ3／ｇ以下の範囲である多孔質ゲルとを含み、
    　熱伝導率が１２．５ｍＷ／ｍＫ以上１４．０ｍＷ／ｍＫ以下の範囲である複合断熱材。     A fiber structure,
    It has a porous structure formed of a silica skeleton formed by polymerizing a trialkoxysilane compound and a tetraalkoxysilane compound, held inside the fiber structure, and having a specific surface area of 550 m 2 / measured by the BET method. in the range of more than 700 meters 2 / g or less g, and a porous gel ranges pore volume below 3.0 cm 3 / g or more 4.0 cm 3 / g as measured by the BJH method,
    A composite heat insulating material having a thermal conductivity in the range of 12.5 mW / mK to 14.0 mW / mK.
  8. 　前記多孔質ゲルの前記シリカ骨格は、前記テトラアルコキシシラン化合物に由来する骨格構造を４％以上１０％以下の範囲で含むことを特徴とする請求項７に記載の複合断熱材。 The composite heat insulating material according to claim 7, wherein the silica skeleton of the porous gel contains a skeleton structure derived from the tetraalkoxysilane compound in a range of 4% to 10%.
  9. 　前記繊維構造物は、繊維同士がバインダ樹脂で融着された不織布であることを特徴とする請求項７に記載の複合断熱材。 The composite heat insulating material according to claim 7, wherein the fiber structure is a non-woven fabric in which the fibers are fused with a binder resin.
  10. 　前記繊維構造物は、プラズマ処理またはシランカップリング剤による表面処理が施されていることを特徴とする請求項７に記載の複合断熱材。 The composite heat insulating material according to claim 7, wherein the fiber structure is subjected to plasma treatment or surface treatment with a silane coupling agent.
  11. 　前記繊維構造物は、繊維配向が揃えられていることを特徴とする請求項７に記載の複合断熱材。 The composite heat insulating material according to claim 7, wherein the fiber structure is aligned in fiber orientation.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112010629A (en) * 2019-05-29 2020-12-01 松下知识产权经营株式会社 Heat insulating sheet, method for producing same, and electronic device and battery unit using heat insulating sheet
WO2022013841A1 (en) * 2020-07-17 2022-01-20 3M Innovative Properties Company Thermal insulation material, method of preparing thermal insulation material, and product prepared from thermal insulation material

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113396134B (en) * 2019-09-30 2022-11-11 株式会社Lg化学 Aerogel felt

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0834678A (en) * 1994-07-27 1996-02-06 Matsushita Electric Works Ltd Aerogel panel
JP2011136859A (en) * 2009-12-28 2011-07-14 Asahi Fiber Glass Co Ltd Fiber heat insulating material and method for manufacturing the same
JP2011162756A (en) * 2010-02-15 2011-08-25 Eiju Sangyo:Kk Method for producing porous silica-fiber composite, porous silica-fiber composite, and vacuum heat insulation material using the same
JP2014035041A (en) * 2012-08-09 2014-02-24 Panasonic Corp Heat insulation material using aerogel particle
JP2014040750A (en) * 2012-08-23 2014-03-06 Panasonic Corp Heat insulating material using aerogel
JP2014095049A (en) * 2012-11-12 2014-05-22 Polymer Associates Kk Cellulose fiber reinforced thermoplastic resin composite molded article
WO2016159196A1 (en) * 2015-04-02 2016-10-06 日東電工株式会社 Porous body, and method for producing porous body
WO2016207096A1 (en) * 2015-06-25 2016-12-29 Wacker Chemie Ag Economically viable process for producing organically modified lyo- or aerogels
JP2017114744A (en) * 2015-12-25 2017-06-29 パナソニックＩｐマネジメント株式会社 Hydrophilic silica aerogel and manufacturing method therefor and heat insulator

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0834678A (en) * 1994-07-27 1996-02-06 Matsushita Electric Works Ltd Aerogel panel
JP2011136859A (en) * 2009-12-28 2011-07-14 Asahi Fiber Glass Co Ltd Fiber heat insulating material and method for manufacturing the same
JP2011162756A (en) * 2010-02-15 2011-08-25 Eiju Sangyo:Kk Method for producing porous silica-fiber composite, porous silica-fiber composite, and vacuum heat insulation material using the same
JP2014035041A (en) * 2012-08-09 2014-02-24 Panasonic Corp Heat insulation material using aerogel particle
JP2014040750A (en) * 2012-08-23 2014-03-06 Panasonic Corp Heat insulating material using aerogel
JP2014095049A (en) * 2012-11-12 2014-05-22 Polymer Associates Kk Cellulose fiber reinforced thermoplastic resin composite molded article
WO2016159196A1 (en) * 2015-04-02 2016-10-06 日東電工株式会社 Porous body, and method for producing porous body
WO2016207096A1 (en) * 2015-06-25 2016-12-29 Wacker Chemie Ag Economically viable process for producing organically modified lyo- or aerogels
JP2017114744A (en) * 2015-12-25 2017-06-29 パナソニックＩｐマネジメント株式会社 Hydrophilic silica aerogel and manufacturing method therefor and heat insulator

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112010629A (en) * 2019-05-29 2020-12-01 松下知识产权经营株式会社 Heat insulating sheet, method for producing same, and electronic device and battery unit using heat insulating sheet
WO2022013841A1 (en) * 2020-07-17 2022-01-20 3M Innovative Properties Company Thermal insulation material, method of preparing thermal insulation material, and product prepared from thermal insulation material

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