WO2019077753A1

WO2019077753A1 - Hydrophilic carbon molded article and production method therefor

Info

Publication number: WO2019077753A1
Application number: PCT/JP2017/038071
Authority: WO
Inventors: 麻理清水; 慶紀内山; 丸山　貴史
Original assignee: 日立化成株式会社
Priority date: 2017-10-20
Filing date: 2017-10-20
Publication date: 2019-04-25
Also published as: JP7173029B2; JPWO2019077753A1

Abstract

This hydrophilic carbon molded article is provided with: a carbon molded article containing a carbonaceous material; and an inorganic oxide layer disposed on at least a part of the surface of the carbon molded article.

Description

Hydrophilic carbon molding and method for producing the same

The present invention relates to a hydrophilic carbon molded body and a method for producing the same.

BACKGROUND ART A carbon molded body is widely used in various industrial fields because it has excellent heat resistance in a non-oxidizing atmosphere, is resistant to chemical attack, is excellent in conductivity, and has extremely low toxicity to the human body.
Since the surface of the carbon molded body is hydrophobic, techniques for hydrophilizing the surface have been studied. As a method of hydrophilizing the surface of the carbon molded body, plasma treatment, UV treatment, ozone treatment and the like can be mentioned. For example, in Patent Document 1, the porous carbon molded body is subjected to ozone oxidation treatment, and the oxygen-containing functional group in the through pores is 0.1 μmol / m ² to 20 μmol / m ² , and the quinone group in the oxygen-containing functional group It is disclosed that a hydrophilic porous carbon molded body can be obtained by setting the ratio of 30% or more. As another hydrophilization process, the method of introduce | transducing a hydrophilic functional group into the surface of a carbon molded object is mentioned. For example, Patent Document 2 discloses a surface-modified carbon molding modified with a hydrophilic sulfonic acid group.

JP 2007-1455653 Japanese Patent Application Publication No. 2007-161511

In recent years, with the background of the expansion of the use of carbon moldings, development of carbon moldings that maintain hydrophilicity for a longer period of time is required.
An object of the present invention is to provide a carbon molded body having excellent hydrophilicity over a long period of time and a method for producing the same in view of the above-mentioned circumstances.

The hydrophilic carbon molded object provided with the carbon molded object containing a <1> carbonaceous material, and the inorganic oxide layer arrange | positioned at at least one part of the surface of the said carbon molded object.
<2> The inorganic oxide layer according to <1>, wherein the inorganic oxide layer contains at least one selected from the group consisting of aluminum oxide, silicon oxide, tin oxide, titanium oxide, selenium oxide, zirconium oxide, and niobium oxide. Hydrophilic carbon moldings.
The hydrophilic carbon molded object as described in <1> or <2> in which the <3> above-mentioned carbonaceous material contains 2 or more types of carbonaceous materials from which crystallinity differs.
In <4> differential thermal analysis (DTA), it has one exothermic peak in a temperature range of 300 ° C. to less than 700 ° C., and one exothermic peak in a temperature range of 700 ° C. to less than 1000 ° C. <1> to <3 The hydrophilic carbon molded object of any one of>.
The hydrophilic carbon molded article according to any one of <1> to <4>, having a volume resistivity of 50 μΩm or less.
The hydrophilic carbon molded article according to any one of <1> to <5>, having a <6> bulk density of 1.20 g / cm ³ to 1.80 g / cm ³ .
<7> The hydrophilic carbon molding according to any one of <1> to <6>, wherein the average thickness of the inorganic oxide layer is 5 μm or less.
Any one of <1>-<7> whose content rate of the inorganic oxide contained in the <8> above-mentioned inorganic oxide layer is 0.01 mass%-5.0 mass% of the said hydrophilic carbon molded object The hydrophilic carbon molded article according to item 1.
The manufacturing method of the hydrophilic carbon molded object provided with the process of immersing the <9> carbon molded object in the liquid containing an inorganic oxide or its precursor, and the process of heating the said carbon molded object taken out from the said liquid.
<10> A step of obtaining a carbon molded body composition containing a carbon powder and a binder, a step of molding and processing the carbon molded body composition to obtain a molded article, and the carbon molded body by carbonizing and firing the molded body A method of producing a hydrophilic carbon molding according to claim 9, further comprising:

According to the present invention, a carbon molded article having excellent hydrophilicity over a long period of time and a method for producing the same are provided.

Hereinafter, modes for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and ranges thereof, and does not limit the present invention.

In the present disclosure, the term “step” includes, in addition to steps independent of other steps, such steps as long as the purpose of the step is achieved even if it can not be clearly distinguished from other steps. .
In the present disclosure, numerical values described before and after “to” are included in the numerical range indicated using “to” as the minimum value and the maximum value, respectively.
The upper limit value or the lower limit value described in one numerical value range may be replaced with the upper limit value or the lower limit value of the other stepwise description numerical value range in the numerical value range described stepwise in the present disclosure. . In addition, in the numerical range described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the example.
In the present disclosure, each component may contain a plurality of corresponding substances. When a plurality of substances corresponding to each component are present in the composition, the content or content of each component is the total content or content of the plurality of substances present in the composition unless otherwise specified. Means quantity.
In the present disclosure, particles corresponding to each component may contain a plurality of types. When there are a plurality of particles corresponding to each component in the composition, the particle diameter of each component means the value for the mixture of the plurality of particles present in the composition unless otherwise specified.
In the present disclosure, the term “layer” may mean that when the region in which the layer is present is observed, it is formed in only a part of the region, in addition to the case where the region is entirely formed. included.

<Hydrophilic carbon molding>
The hydrophilic carbon molding of the present disclosure comprises a carbon molding containing a carbonaceous material and an inorganic oxide layer disposed on at least a part of the surface of the carbon molding.

The hydrophilic carbon molded body having the above-described configuration exhibits excellent hydrophilicity by the inorganic oxide layer being disposed on at least a part of the surface of the carbon molded body. Furthermore, this hydrophilicity persists over a long period of time.

In the present disclosure, the “hydrophilic carbon molded body” means that the inorganic oxide layer is disposed on at least a part of the surface of the carbon molded body, which is more hydrophilic than the case where the inorganic oxide layer is not provided. Means an improved carbon molding. The method of determining whether the hydrophilicity of the carbon molded body is improved is not particularly limited. For example, it can be determined based on the amount of water absorption within a fixed time, the time required for water absorption of a fixed amount, the contact angle, and the like.

In the present disclosure, “the surface of a carbon molded body” means the surface of the boundary between the inside of the carbon molded body (the inorganic oxide layer when the inorganic oxide layer is disposed) and the outer side. Therefore, for example, when the carbon compact has pores, the inner wall portion of the pores also corresponds to the "surface of the carbon compact".

(Carbon molded body)
The material of the carbon molded body is not particularly limited as long as it contains a carbonaceous material. Examples of the carbonaceous material include graphite, amorphous carbon, carbon fiber and the like. The carbonaceous material contained in the carbon molded body may be one kind alone or two or more kinds. The carbon molded body may contain components other than the carbonaceous material. In addition, only a part of the region (for example, the surface) may include the carbonaceous material.

The carbon compact preferably contains two or more kinds of carbonaceous materials having different crystallinity. As a combination of two or more kinds of carbonaceous materials having different crystallinity, for example, carbonaceous matter derived from these raw materials when producing a carbon molded body using two or more kinds of raw materials (for example, carbon powder and a binder) A combination of materials may be mentioned.

As a carbon powder used for manufacture of a carbon molded object, artificial graphite, natural graphite, expanded graphite, carbon black, and these mixtures are mentioned, for example. A carbon molded body in which at least a part of the raw material is carbon powder is excellent in heat resistance and chemical resistance, has a low electrical resistance, a low friction coefficient, and tends to have a high thermal conductivity. The carbon powder may be used alone or in combination of two or more.

The particle diameter of the carbon powder is not particularly limited, but for example, one having a volume average particle diameter (D50) of 1 μm to 150 μm is preferable, and one having a volume average particle diameter (D50) of 5 μm to 70 μm is more preferable. When the volume average particle diameter (D50) of the carbon powder is 1 μm or more, good moldability tends to be obtained, and when it is 150 μm or less, good strength tends to be obtained.
The volume average particle diameter of the carbon powder is a particle diameter at which integration from the small diameter side is 50% in the volume-based particle size distribution curve obtained by the laser diffraction / scattering method.

As a binder used for manufacture of a carbon molded object, a thermosetting resin, petroleum, the extract component from coal etc., etc. are mentioned, for example. Examples of the thermosetting resin include epoxy resin, phenol resin, furan resin, polyimide resin, unsaturated polyester resin and the like. Examples of extracted components from petroleum, coal and the like include petroleum pitch, coal pitch, synthetic pitch, coal tar and the like. Among these, phenol resins are preferable because they are excellent in moldability and carbonization yield. The binder may be used alone or in combination of two or more.

Whether or not the carbon molded body contains two or more kinds of carbonaceous materials different in crystallinity, for example, the heat generation of two or more DTAs which can be distinguished from each other in differential thermal analysis (DTA) in an air stream. It can be confirmed by whether or not a peak (hereinafter, also simply referred to as "pyrogenic peak") is observed. Here, that the plurality of exothermic peaks are “identifiable” means that the peak values of the exothermic peaks are separated by at least 5 ° C., as long as they are distinguishable in terms of measurement accuracy of the device.

The differential thermal analysis (DTA) can be performed using a differential thermal-gravity simultaneous measurement apparatus (for example, DTG-60H manufactured by Shimadzu Corporation). Specifically, measurement can be performed at a temperature rising rate of 10 ° C./min under a flow of 200 ml / min of dry air with α-alumina as a reference.

The carbon compact preferably has at least two DTA exothermic peaks in the temperature range of 300 ° C. to 1000 ° C. as measured under the above conditions. In this case, the temperature difference between the exothermic peaks is not particularly limited, but the temperature difference between the exothermic peak on the highest temperature side and the exothermic peak on the lowest temperature side is preferably 300 ° C. or less, and 200 ° C. or more and 290 ° C. It is more preferable that the temperature be as follows, particularly preferably 215 ° C. or more and 280 ° C. or less, and most preferably 220 ° C. or more and 275 ° C. or less.

From the viewpoint of volume specific resistance, the exothermic peak is an exothermic peak observed in a temperature range of 300 ° C. to less than 700 ° C. (hereinafter, may be referred to as “low temperature range”), and a temperature of 700 ° C. to 1000 ° C. It is preferable to include an exothermic peak observed in a range (hereinafter sometimes referred to as “high temperature range”), and one exothermic peak observed in the low temperature range and one exothermic peak observed in the high temperature range It is more preferable to have two in total.

The hydrophilic carbon molding may have pores. When the hydrophilic carbon molded product has pores, the proportion of the pores (porosity) is not particularly limited, but is preferably 10% by volume to 50% by volume, for example, 15% by volume to 45% by volume. %, More preferably 20% to 40% by volume. If the porosity is in the above range, good strength tends to be obtained. The porosity can be adjusted, for example, by the blending ratio of raw materials (for example, carbon powder and binder) at the time of production of the carbon molded body.

When the hydrophilic carbon molding has pores, an inorganic oxide layer may be formed on the inner wall portion of the pores. In this case, even if the inorganic oxide layer is formed on all the inner wall portions of the pores, the inorganic oxide layer may be formed on only a part.

When the hydrophilic carbon molding has pores, the size of the pores is not particularly limited. For example, the median pore diameter (D50) of the pores is preferably 1 μm to 10 μm, more preferably 1.5 μm to 8 μm, and still more preferably 2 μm to 7 μm. When the median pore diameter (D50) of the pores is in the above range, good water absorption tends to be obtained. The size of the pores can be adjusted, for example, by the blending ratio of raw materials (for example, carbon powder and binder) at the time of production of the carbon molded body.

The volume resistivity of the hydrophilic carbon molding is not particularly limited. For example, 50 μΩm or less is preferable, 1 μΩm to 50 μΩm is more preferable, 5 μΩm to 40 μΩm is more preferable, and 10 μΩm to 30 μΩm is particularly preferable. If the volume resistivity of the hydrophilic carbon molding is in the above range, good conductivity tends to be obtained. The volume resistivity can be adjusted, for example, by the blending ratio of raw materials (eg, carbon powder and binder) at the time of production of the carbon molded body.

The bulk density of the hydrophilic carbon molding is not particularly limited. For example, it is preferably 1.20 g / cm ³ to 1.80 g / cm ³ , more preferably 1.25 g / cm ³ to 1.70 g / cm ³ , and 1.3 g / cm ³ to 1. More preferably, it is 65 g / cm ³ . If the bulk density of the hydrophilic carbon molding is in the above range, good strength tends to be obtained. The bulk density can be adjusted, for example, by the blending ratio of raw materials (for example, carbon powder and binder) at the time of production of the carbon molded body.

The bending strength of the hydrophilic carbon molding is not particularly limited. For example, the pressure is preferably 8 MPa or more, more preferably 10 MPa or more, and still more preferably 15 MPa or more. The upper limit of the bending strength is preferably, for example, 50 MPa or less. When the flexural strength of the hydrophilic carbon molding is in the above range, the external pressure resistance tends to be good. The bending strength can be adjusted, for example, by the blending ratio of the raw materials (for example, carbon powder and binder) at the time of production of the carbon molded body.

(Inorganic oxide layer)
The inorganic oxide layer is disposed on at least a part of the surface of the carbon compact. As a method of confirming whether the inorganic oxide layer is disposed on at least a part of the surface of the carbon molded body, a method of observing the surface of the carbon molded body with an electron microscope or the like, energy dispersive X-ray analysis (Energy A method of elemental mapping by dispersive X-ray spectrometry (EDX, EDS), a method of elemental analysis by X-ray photoelectron spectroscopy (XPS), and the like can be mentioned, and a suitable one can be selected from these.

The type of inorganic oxide contained in the inorganic oxide layer is not particularly limited. From the viewpoint of imparting good hydrophilicity to the surface of the carbon molded body, it contains at least one selected from the group consisting of aluminum oxide, silicon oxide, tin oxide, titanium oxide, selenium oxide, zirconium oxide and niobium oxide. preferable. The inorganic oxide contained in the inorganic oxide layer may be one kind alone or two or more kinds.

The inorganic oxide layer may be composed only of an inorganic oxide, and from the viewpoint of imparting good hydrophilicity to the surface of the carbon molded body, the inorganic oxide layer may be composed only of an inorganic oxide or an inorganic oxide The content of is preferably 90% by mass or more.

The thickness of the inorganic oxide layer is not particularly limited. For example, the average thickness is preferably 5 μm or less. The lower limit of the average thickness of the inorganic oxide is not particularly limited, but is preferably 0.05 μm or more. The average thickness of the inorganic oxide layer is an arithmetic mean value of values measured at any five places.
The mass per unit area of the inorganic oxide layer is not particularly limited. For example, it may be between 0.1 mg / m ² and 1.0 mg / m ² .

The content of the inorganic oxide in the hydrophilic carbon molding is not particularly limited. For example, the content is preferably 0.01% by mass to 5.0% by mass, more preferably 0.05% by mass to 3.0% by mass, based on the whole of the hydrophilic carbon molded body, 0.1% by mass or more Particularly preferred is 2.0% by mass. If the content of the inorganic oxide is in the above range, good hydrophilicity tends to be obtained.

<Method of producing hydrophilic carbon molding>
The method for producing a hydrophilic carbon molding according to the present disclosure includes the steps of immersing the carbon molding in a liquid containing an inorganic oxide or a precursor thereof, and heating the carbon molding taken out of the liquid. .

According to the above method, the inorganic oxide layer can be formed on at least a part of the surface of the carbon molded body. Further, even when the carbon molded body has pores, the liquid containing the inorganic oxide can enter the inside of the pores and form an inorganic oxide layer on the inner wall portion of the pores.

In the above method, a liquid containing an inorganic oxide or a precursor thereof may be prepared, for example, by mixing an inorganic oxide or a substance that becomes an inorganic oxide upon heating (a precursor of an inorganic oxide) into a liquid medium. it can. The inorganic oxide or its precursor may be in a state of being dissolved or dispersed in a liquid medium.

The type of liquid medium is not particularly limited. For example, water, alcohol solvents, ether solvents, ester solvents, ketone solvents, aprotic polar solvents, glycol monoether solvents, terpene solvents and the like can be mentioned. The liquid medium may be used alone or in combination of two or more.

Specific examples of the liquid containing an inorganic oxide or a precursor thereof include metal alkoxide solution, metal chelate solution, dispersion liquid of metal oxide fine particles, liquid surface coating agent, liquid coupling agent and the like. The liquid containing the inorganic oxide or the precursor thereof may be prepared by itself or a commercially available product. Examples of commercially available products include dispersions of titanium oxide fine particles such as trade name of Taki Chemical Co., Ltd., Tinoc A-6, M-6, AM-15, CZP-223 and the like.

The type of inorganic oxide is not particularly limited. For example, aluminum oxide, silicon oxide, tin oxide, titanium oxide, selenium oxide, zirconium oxide and niobium oxide can be mentioned. Among these, titanium oxide is preferable.

The type of inorganic oxide precursor is not particularly limited. For example, the alkoxide compound of the element contained in the inorganic oxide mentioned above is mentioned. Specifically, aluminum alkoxides such as aluminum butoxide and aluminum isopropoxide, silane alkoxides such as tetraethoxysilane and tetramethoxysilane, tin alkoxides such as tin n-butoxide and tin tetraisopropoxide, titanium butoxide, Titanium alkoxides such as titanium tetraisopropoxide, selenium alkoxides such as sodium tert-butyl selenoxide, zirconium alkoxides such as zirconium butoxide, zirconium isopropoxide, niobium alkoxides such as niobium butoxide, niobium isopropoxide, etc. Can be mentioned. Among these, titanium alkoxides are preferable, and titanium butoxide and titanium tetraisopropoxide are more preferable.

The method for immersing the carbon compact in a liquid containing an inorganic oxide is not particularly limited, and a known method may be used. The time for immersing the carbonaceous material is also not particularly limited, and can be appropriately adjusted depending on the number and area of the carbon molded body. The temperature of the liquid containing the inorganic oxide at the time of immersing the carbon molded body is also not particularly limited, and cooling or heating may be performed as necessary.

The method for heating the carbon compact taken out from the liquid containing the inorganic oxide or the precursor thereof is not particularly limited, and can be performed by a known method.
In the present disclosure, "heating" includes those intended for drying, sintering and the like. From the viewpoint of forming an inorganic oxide layer excellent in hydrophilicity, the heating is preferably performed in this order of drying and sintering. The temperature of drying is not particularly limited, but is preferably 80 ° C. to 250 ° C., more preferably 100 ° C. to 230 ° C., and still more preferably 120 ° C. to 210 ° C. The sintering temperature is not particularly limited, but is, for example, preferably 280 ° C. to 500 ° C., more preferably 290 ° C. to 450 ° C., and still more preferably 300 ° C. to 400 ° C.

The heating temperature is not particularly limited, but it is preferably, for example, 80 ° C. to 500 ° C., and 100 ° C. to 400 ° C., from the viewpoint of forming an inorganic oxide layer having excellent hydrophilicity. Is more preferable, and 150.degree. C. to 350.degree. C. is more preferable. The heating step may be performed at a constant temperature from start to finish or may be performed at different temperatures.

The heating time is not particularly limited, but may be, for example, 30 minutes to 180 minutes.

The method may further comprise the step of making the carbon compact prior to immersion in the liquid comprising the inorganic oxide.
The method for producing the carbon molded body is not particularly limited. For example, a step of obtaining a carbon molded body composition containing (A) carbon powder and a binder as shown below, (B) a step of molding and processing the carbon molded body composition to obtain a molded article, and (C) Carbonizing and firing the molded product to obtain a carbon molded product.

(Step (A))
In step (A), a carbon molded body composition containing carbon powder and a binder is obtained. The carbon molded body composition can be obtained, for example, by mixing the above-described carbon powder and a binder. The mixing method is not particularly limited, and the mixing can be performed by a known method.

The blending ratio of the carbon powder and the binder is not particularly limited, but for example, it is preferable that carbon powder / binder = 95/5 to 60/40 as a ratio (mass standard) after carbonation, It is more preferably 90/10 to 70/30, and still more preferably 85/15 to 75/25. When the blending ratio of the binder is 5% by mass or more of the total of the carbon powder and the binder, the carbon powder and the binder are sufficiently mixed, and the formability becomes good, so that the bending strength of the obtained carbon molded body becomes good. There is a tendency. In addition, when the blending ratio of the binder is 40% by mass or less of the total of the carbon powder and the binder, the porosity of the carbon compact does not become too low, and the swelling of the carbon compact tends to be suppressed at the time of carbonization and firing.

The carbon molded body composition may be mixed with components other than the carbon powder and the binder. As such a component, a component which does not correspond to a carbon powder and a binder and which is carbonized by carbonization and firing in the step (C), a component which is volatilized in the carbonization and firing, and the like can be mentioned.

(Step (B))
In the step (B), the carbon molded body composition obtained in the step (A) is molded to obtain a molded article. The method of molding is not particularly limited. For example, a method of pouring a carbon molded body composition into a mold and heating and pressing may be mentioned.

The heating and pressurizing conditions are not particularly limited. The heating temperature is, for example, preferably 150 ° C. to 250 ° C., more preferably 160 ° C. to 240 ° C., and still more preferably 170 ° C. to 230 ° C. The pressure at the time of pressurization is, for example, preferably 0.5 MPa to 10 MPa, more preferably 1 MPa to 8 MPa, and still more preferably 2 MPa to 5 MPa. The heating and pressurizing time is, for example, preferably 0.1 minutes to 30 minutes, more preferably 0.5 minutes to 20 minutes, and still more preferably 1 minute to 10 minutes.

(Step (C))
In the step (C), the molded product obtained in the step (B) is carbonized and fired to obtain a carbon molded body. The method of carbonization and firing is not particularly limited, but is preferably performed in a vacuum or an inert gas atmosphere. The inert gas is not particularly limited, and nitrogen gas, helium gas, argon gas and the like can be mentioned. The firing temperature is not particularly limited, but is preferably in the range of 800 ° C. to 1500 ° C. When the firing temperature is in the above range, carbonization of the binder tends to be sufficiently promoted, which is also advantageous in terms of energy efficiency at the time of production.

Hereinafter, embodiments of the present disclosure will be more specifically described based on examples, but the present disclosure is not limited to these examples. In addition, unless there is particular notice, "part" and "%" are mass references.

Example 1
85 parts by mass of artificial graphite powder having an average particle diameter (D50) of 40 μm as carbon powder and 15 parts by mass of phenol resin as a binder were mixed to obtain a carbon molded body composition. The resultant was filled in a molding die, and heat compression molding was performed at 190 ° C. and 1000 kN for 5 minutes to produce a molding having a length of 140 mm, a width of 190 mm and a thickness of 2.5 mm. The molded product was fired at 900 ° C. for 60 minutes in an inert gas atmosphere to obtain a carbon molded product.

The obtained carbon molded body is cut into a size of 50 mm in length and 50 mm in width, and titanium tetraisopropoxide (Wako Pure Chemical Industries, Ltd., structural formula: [(CH ₃ ) ₂ CHO] ₄ Ti) in methanol In a liquid diluted to 0.5% by mass for 30 minutes.

After immersion, the carbon molded body was taken out, the solvent on the surface was naturally dried, and then heated (dried) for 60 minutes with a dryer set at 150 ° C. Thereafter, heating (sintering) was performed at 350 ° C. for 60 minutes to obtain a carbon molded body (hydrophilic carbon molded body) having the inorganic oxide layer formed thereon.

The following measurement was implemented about the obtained hydrophilic carbon molded object (50 mm in length, 50 mm in width, 2.5 mm in thickness). The results are shown in Table 1.

[1] Bulk Density The hydrophilic carbon molding was dried for 60 minutes in a dryer set at 100 ° C., and then the mass was measured. In addition, the dimensions of the hydrophilic carbon molding were measured, and the volume was calculated. The bulk density (g / cm ³ ) was calculated by dividing the obtained mass by volume.

[2] Volume Specific Resistance A hydrophilic carbon molded body was sandwiched between two smooth copper plates subjected to gold plating, and the volume specific resistance (μΩm) was measured from the drop in voltage when a constant current was applied.

[3] Bending Strength The bending strength (MPa) was measured by the three-point bending test described in JIS K-6911 (2006).

[4] DTA heat generation peak temperature difference Of the two heat generation peaks measured by the TG-DTA measurement device, the value obtained by subtracting the peak temperature on the low temperature side from the peak temperature on the high temperature side was taken as the DTA heat generation peak temperature difference (° C) .

[5] Median Pore Diameter The pore size (median pore diameter, μm) of the hydrophilic carbon molding was measured by mercury porosimetry, and it was calculated by data processing.

[6] Porosity The porosity (volume%) of the hydrophilic carbon molding was measured by the mercury intrusion method, and calculated by data processing.

[7] Content of Inorganic Oxide The value obtained by subtracting the mass B before immersion from the mass A of the carbon molded body after immersion in the liquid containing titanium tetraisopropoxide is divided by the mass B before immersion The value obtained by multiplying the above value by 100 is defined as the content (mass%) of the inorganic oxide.

[8] Water absorption time (immediately after production)
10 μL of pure water was dropped by a micropipette on the hydrophilic carbon molding immediately after production, and the time of water absorption was measured by a timer. It measured similarly in five places in a surface, and calculated | required the arithmetic mean value.

[9] Water absorption time (one year after production)
10 μL of pure water was dropped by a micropipette on the hydrophilic carbon molded body stored at room temperature (20 ° C. to 30 ° C.) for one year, and the time of water absorption was measured by a timer. It measured similarly in five places in a surface, and calculated the arithmetic mean value.

Example 2
A hydrophilic carbon molded body was produced and evaluated in the same manner as in Example 1 except that a carbon molded body having a bulk density different from that of Example 1 was used.

Example 3
A carbon compact having a bulk density different from that of Example 1 was used, and as a liquid containing an inorganic oxide, a fine particle titanium oxide sol (Taki Chemical Co., Ltd., CZP-223) diluted to 2% by mass with methanol was used. A hydrophilic carbon molded body was produced and evaluated in the same manner as in Example 1 except for the above.

Example 4
A carbon compact having a bulk density different from that of Example 1 was used, and as a liquid containing an inorganic oxide, a fine particle titanium oxide sol (Taki Chemical Co., Ltd., AM-15) diluted to 2% by mass with methanol was used. A hydrophilic carbon molded body was produced and evaluated in the same manner as in Example 1 except for the above.

Example 5
A carbon compact having a bulk density different from that of Example 1 was used, and as a liquid containing an inorganic oxide, one obtained by diluting fine particle titanium oxide sol (Taki Chemical Co., Ltd., M-6) with methanol to 1% by mass was used. A hydrophilic carbon molded body was produced and evaluated in the same manner as in Example 1 except for the above.

Example 6
A carbon compact having a bulk density different from that of Example 1 was used, and as a liquid containing an inorganic oxide, one obtained by diluting fine particle titanium oxide sol (Taki Chemical Co., Ltd., M-6) with methanol to 1% by mass was used. A hydrophilic carbon molded body was produced and evaluated in the same manner as in Example 1 except for the above.

Example 7
A carbon compact having a bulk density different from that of Example 1 was used, and as a liquid containing an inorganic oxide, one obtained by diluting fine particle titanium oxide sol (Taki Chemical Co., Ltd., M-6) with methanol to 1% by mass was used. A hydrophilic carbon molded body was produced and evaluated in the same manner as in Example 1 except for the above.

Comparative Example 1
Using a carbon compact having a bulk density different from that of Example 1, the carbon compact in a state in which immersion (hydrophilization treatment) in a liquid containing an inorganic oxide was not performed was evaluated in the same manner as in Example 1.

The above results are summarized in the following table.

As shown in Table 1, the carbon moldings of Examples 1 to 7 which have been subjected to the hydrophilization treatment absorb a certain amount of water as compared with the carbon moldings of Comparative Example 1 which have not been subjected to the hydrophilization treatment. It was found that the time to do so was short and the hydrophilicity was excellent. Furthermore, it was found that the hydrophilicity improvement effect by the hydrophilization treatment continued even after one year.

All documents, patent applications, and technical standards described herein are as specific and individually as individual documents, patent applications, and technical standards are incorporated by reference. Hereby incorporated by reference.

Claims

A hydrophilic carbon molded body, comprising: a carbon molded body containing a carbonaceous material; and an inorganic oxide layer disposed on at least a part of the surface of the carbon molded body.
The hydrophilicity according to claim 1, wherein the inorganic oxide layer comprises at least one selected from the group consisting of aluminum oxide, silicon oxide, tin oxide, titanium oxide, selenium oxide, zirconium oxide, and niobium oxide. Carbon moldings.
The hydrophilic carbon molded object according to claim 1 or 2 in which said carbonaceous material contains two or more sorts of carbonaceous materials from which crystallinity differs.
The differential thermal analysis (DTA) according to any one of claims 1 to 3, which has one exothermic peak in a temperature range of 300 ° C to less than 700 ° C and one exothermic peak in a temperature range of 700 ° C to less than 1000 ° C. The hydrophilic carbon molded article according to any one of the preceding claims.
The hydrophilic carbon molding according to any one of claims 1 to 4, which has a volume resistivity of 50 μΩm or less.
A bulk density of 1.20g / cm 3 ~ 1.80g / cm 3, hydrophilic carbon molded body according to any one of claims 1 to 5.
The hydrophilic carbon molded article according to any one of claims 1 to 6, wherein the average thickness of the inorganic oxide layer is 5 μm or less.
The content rate of the inorganic oxide contained in the said inorganic oxide layer is 0.01 mass%-5.0 mass% of the said hydrophilic carbon molded object in any one of Claims 1-7. The hydrophilic carbon molded object as described.
A method for producing a hydrophilic carbon molded body, comprising: a step of immersing a carbon molded body in a liquid containing an inorganic oxide or a precursor thereof; and a step of heating the carbon molded body taken out of the liquid.
A step of obtaining a carbon molding composition containing carbon powder and a binder, a step of molding the carbon molding composition to obtain a molding, and a step of carbonizing and sintering the molding to obtain the carbon molding The method for producing a hydrophilic carbon molding according to claim 9, further comprising