JP2020186142A - Silica-carbon composite material and its manufacturing method - Google Patents

Abstract

To provide a silica-carbon composite material capable of enhancing affinity between silica and a rubber material without using a silane coupling agent and sufficiently exhibiting properties of carbon and silica, and to provide a method for producing the silica-carbon composite material.SOLUTION: A silica-carbon composite material is obtained by using biomass derived from a silicate plant as a raw material and containing a composite of amorphous silica and a carbon porous body.SELECTED DRAWING: Figure 13

Description

The present invention relates to a silica-carbon composite material and a method for producing the same.

Tens of millions of tons of rice husks are generated annually around the world, most of which have been treated as waste. On the other hand, in recent years, attention has been paid to the fact that rice husks contain abundant carbon and silica, and their use as fillers for rubber materials is being promoted.

In general, it is known that rubber is reinforced by adding carbon black, and its fatigue resistance and wear resistance are significantly improved. Further, since silica has better low loss property, wet skid resistance and the like as compared with carbon black, it is used as the filler in order to reduce the rolling resistance of the tire and the like.

As a technique for using rice husks as the filler, for example, a rubber composition containing rice husk charcoal, a rubber composition obtained by adding silica particles to rice husk charcoal, or the like is blended into a tire, and rolling resistance performance, etc. Technology to improve; technology to improve on-ice performance and wear resistance by blending a rubber composition for tread containing rice husk charcoal and a silane coupling agent into a tire; a rubber reinforcing material containing rice husk charcoal as a main component There are known techniques for using and improving the durability of tires and the like (Patent Documents 1 to 8).

Further, there is also known a technique of applying a rubber composition obtained by coating the surface of carbon black with silica by chemical treatment to a tire or the like (Patent Document 9).

Japanese Unexamined Patent Publication No. 2009-114251 (published on May 28, 2009) Japanese Unexamined Patent Publication No. 2009-114252 (published on May 28, 2009) Japanese Unexamined Patent Publication No. 2009-114253 (published on May 28, 2009) Japanese Unexamined Patent Publication No. 2009-114254 (published on May 28, 2009) Japanese Unexamined Patent Publication No. 2009-14255 (published on May 28, 2009) Japanese Unexamined Patent Publication No. 2009-114257 (published on May 28, 2009) Japanese Unexamined Patent Publication No. 2011-68884 (published on April 7, 2011) Japanese Unexamined Patent Publication No. 2013-155254 (published on August 15, 2013) Japanese Unexamined Patent Publication No. 9-118837 (published on May 6, 1997)

As described above, many fillers for rubber materials have been developed utilizing the fact that rice husks contain a large amount of carbon and silica. On the other hand, carbon has a high affinity with rubber materials, but silica has a low affinity with rubber materials because it is hydrophilic. Therefore, the fillers described in Patent Documents 1 to 8 use a silane coupling agent that chemically bonds the rubber material and the surface of the silica particles in order to improve the affinity.

However, since the silane coupling agent is expensive and a large amount of the silane coupling agent must be used, there is a problem that the manufacturing cost of tires and the like is increased. Further, since the silane coupling agent contains sulfur molecules, there is a problem that so-called burning occurs when the processing temperature is raised.

As described above, it is preferable to use a silane coupling agent in order to improve the affinity, but in consideration of the above problems, even when the silane coupling agent is not used, the silane coupling agent can be used. It can be said that it is more preferable that the filler is capable of exhibiting the affinity comparable to that used.

The filler described in Patent Document 9 has a structure in which carbon black is dispersed in water and the surface of the carbon black is treated with silica by a wet reaction between a metal silicate and an acid. The filler may exhibit excellent physical properties due to its structure.

However, due to the treatment method of treating the surface with silica, the filler aggregates due to silanol-silanol interaction without a silane coupling agent, and sufficient dispersibility cannot be ensured. In addition, carbon black is a petroleum-derived product, and since the surface is treated with silica, it has environmental and cost problems such as increased sustainability and energy cost.

Therefore, one aspect of the present invention can enhance the affinity between silica and the rubber material in both cases where the silane coupling agent is not used in combination and when it is used in combination, and the characteristics of carbon and silica. It is an object of the present invention to provide a silica-carbon composite material capable of fully exerting the above and a method for producing the same.

In order to solve the above problems, the silica-carbon composite material according to one aspect of the present invention and the method for producing the silica-carbon composite material according to one aspect of the present invention include the following inventions.

[1] A silica-carbon composite material using biomass derived from a silicic acid plant as a raw material and containing a composite of amorphous silica and a carbon porous body.

[2] The silica-carbon composite material according to [1], which contains 10% by mass or more and 70% by mass or less of carbon contained in the biomass.

[3] The silica-carbon composite material according to [1] or [2], wherein the BET specific surface area is 100 m ² / g or more and 900 m ² / g or less.

[4] The silica-carbon composite material according to [3], wherein the BET specific surface area is 100 m ² / g or more and 350 m ² / g or less.

[5] The silica-carbon composite material according to any one of [1] to [4], wherein the average particle size (D50) is 0.1 μm or more and 10 μm or less.

[6] The silica-carbon composite material according to any one of [1] to [5], which has amphipathic properties.

[7] An additive for a polymer material containing the silica-carbon composite material according to any one of [1] to [6].

[8] A rubber composition containing a rubber component and the additive for a polymer material according to [7], wherein the content of the additive for a polymer material with respect to the rubber component is 3 phr or more and 140 phr or less. There is a rubber composition.

[9] A rubber product containing the rubber composition according to [8].

[10] A gasification step of gasifying a part of carbon contained in the biomass by supplying superheated steam to the biomass derived from a silicic acid plant.
A method for producing a silica-carbon composite material, which comprises a recovery step of recovering a biomass residue that remains as a solid content without being gasified in the gasification step as a silica-carbon composite material.

[11] The biomass residue obtained by the gasification step is contained in the biomass residue by placing it in an atmosphere higher than that of the gasification step between the gasification step and the recovery step. The method for producing a silica-carbon composite material according to [10], which comprises a tar decomposition step of decomposing biomass.

According to one aspect of the present invention, it has a high affinity with a rubber component even though it contains silica, and in both cases where a silane coupling agent is not used in combination and when it is used in combination, conventional carbon. It is possible to provide a material derived from biomass derived from a silicic acid plant, which can exhibit the same performance as the silica-containing composition.

It is a schematic diagram which shows an example of the outline of the structure of the gasification furnace which can carry out the gasification step in the manufacturing method of the silica-carbon composite material which concerns on one Embodiment of this invention. It is a figure which shows the change of the BET specific surface area of the silica-carbon composite material which concerns on one Embodiment of this invention when the gasification rate in a gasification step is changed using rice straw and rice husk in an Example. .. It is a figure which added the result when sawdust, bamboo, and bark were added to the result shown in FIG. It is a figure which showed the composition of a gas and a biomass residue when the gasification rate in a gasification step is 30% to 90% in an Example. It is a figure showing the composition of rice husk, the yield of biomass residue when the gasification rate is 30% to 90%, and the composition of biomass residue. It is a figure which shows the observation result (magnification 100 times) by SEM of the silica-carbon composite material which has not been pulverized. It is a figure which shows the observation result (magnification 500 times) by SEM of the silica-carbon composite material which has not been pulverized. It is a figure which shows the observation result by SEM of the silica-carbon composite material which performed the pulverization treatment and has an average particle diameter (D50) of about 1 μm. It is an SEM photograph which observed the large lumpy particle shown in FIG. 8 at a magnification of 14 times. It is a figure which shows the result of the mapping analysis of the large massive particle shown in FIG. It is a figure which shows the result of the mapping analysis of the small tufted particle shown in FIG. 8, and is the SEM photograph which observed the small tufted particle at a magnification of 14 times. The result of the mapping analysis of the small tufted particles shown in FIG. 8 is shown. It is a figure which shows that the silica-carbon composite material which concerns on one Embodiment of this invention has amphipathic nature.

An embodiment of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to the configurations described below, and various modifications can be made within the scope of the claims, and the technical means disclosed in the different embodiments may be appropriately combined. The obtained embodiments are also included in the technical scope of the present invention. Unless otherwise specified in the present specification, "A to B" representing a numerical range means "A or more and B or less". Further, "mass" and "weight", and "mass%" and "weight%" are treated as synonyms.

[Embodiment 1. Silica / carbon composite material]
(1) Silica-Carbon Composite Material The silica-carbon composite material according to the embodiment of the present invention is made from biomass derived from a silicic acid plant and contains a composite of amorphous silica and a carbon porous body. To do.

The biomass derived from the silicic acid plant is not particularly limited as long as it can be obtained from the silicic acid plant and contains carbon and amorphous silica. For example, rice husks, rice straw, straw, bamboo, sawdust, bark, wood chips, grass and the like can be mentioned. The silica-carbon composite material according to one embodiment of the present invention can be prepared, for example, by the method for producing a silica-carbon composite material according to one embodiment of the present invention, which will be described later.

The "amorphous silica" refers to silica that is not in a crystalline state. Crystalline silica is not preferable because it may be carcinogenic to the human body. The silica contained in the biomass has an amorphous structure. On the other hand, when the biomass is subjected to a water-gas shift reaction at a high temperature of about 950 ° C., a part of silica may crystallize. As will be described later, the silica-carbon composite material according to the embodiment of the present invention. Can be prepared at a temperature of 800 ° C. or lower. Therefore, the silica-carbon composite material according to the embodiment of the present invention does not contain crystalline silica.

The "carbon porous body" is carbon having a large number of pores on the surface and inside, and having a network-like structure in which these pores are connected. Further, the "composite of amorphous silica and carbon porous body" means that amorphous silica and carbon porous body are not merely a mixture but are inseparably composited to form one material. It means something that exists.

As shown in Examples described later, when the silica-carbon composite material according to the embodiment of the present invention is observed with a scanning electron microscope (SEM), a large number of small tufted particles are aggregated and adhered to the large lump particles. You can see that. Further, when the silica-carbon composite material according to the embodiment of the present invention is analyzed by an electron probe X-ray microanalyzer (EPMA), the lumpy particles contain a large amount of carbon, and the tufted particles contain a large amount of silica. It can be seen that the agglomerate particles and the tufted particles are not composed of a single component of carbon or silica. From these results, it can be said that the silica-carbon composite material according to the embodiment of the present invention contains a composite of amorphous silica and a carbon porous body.

It is considered that the silica-carbon composite material according to the embodiment of the present invention is formed by capturing and adsorbing amorphous silica in a large number of pores on the surface and inside of the carbon porous body. In addition, the adsorbed amorphous silica does not easily separate from the carbon porous body. As a result, although it contains amorphous silica which is hydrophilic and has a low affinity with the rubber component, rubber is used in both cases where the silane coupling agent is not used and when it is used in combination. It can show high affinity with the ingredients.

Further, as shown in Examples described later, the silica-carbon composite material according to the embodiment of the present invention contains amorphous silica and carbon in which a silane coupling agent is used in combination even when the silane coupling agent is not used in combination. It is possible to show physical properties equal to or better than the mixture of.

Therefore, according to one embodiment of the present invention, it is possible to provide a filler having a rubber component that exhibits excellent physical properties in both cases where the silane coupling agent is not used in combination and when it is used in combination.

The content of the composite of amorphous silica and the carbon porous body in 100% by mass of the silica-carbon composite material according to the embodiment of the present invention is preferably 50% by mass or more, preferably 70% by mass. The above is more preferable, and 100% by mass is most preferable. When the content is 50% by mass or more, when the silica / carbon composite material is contained in a rubber product such as a tire, the desired properties of amorphous silica and carbon can be sufficiently exhibited.

The silica-carbon composite material according to the embodiment of the present invention may contain other components such as potassium, sodium, iron and phosphorus in addition to the composite.

The silica-carbon composite material according to the embodiment of the present invention preferably contains 10% by mass or more and 70% by mass or less of carbon contained in the biomass.

As shown in Examples described later, the carbon contained in the biomass may be gasified and discharged, or may remain in the silica-carbon composite material without being gasified. In the present specification, the ratio of the weight of gasified carbon to the weight of carbon in biomass is referred to as "gasification rate", but it remains in the silica-carbon composite by adjusting the gasification rate. The amount of carbon can be adjusted, and as a result, the BET specific surface area of the silica-carbon composite material can be optimized.

When the silica-carbon composite material according to the embodiment of the present invention contains 10% by mass or more and 70% by mass or less of carbon contained in the biomass, the BET specific surface area of the silica-carbon composite material will be described later. As described above, it can be 100 m ² / g or more and 900 m ² / g or less.

The silica-carbon composite material according to the embodiment of the present invention preferably has a BET specific surface area of 100 m ² / g or more and 900 m ² / g or less. It is also preferable that the BET specific surface area is 100 m ² / g or more and 350 m ² / g or less.

Among the above-mentioned biomass derived from silicic acid plants, rice straw, rice husks and straw have a high ash content, which is about 20% by weight. On the other hand, bamboo, sawdust, bark, wood chips and grass have a low ash content and contain about several weight%.

Therefore, the BET specific surface area of the silica-carbon composite material differs depending on the type of biomass used as a raw material, but the configuration in which the BET specific surface area is 100 m ² / g or more and 900 m ² / g or less means that the carbon is amorphous. It has a porous state suitable for forming a complex with silica, and is suitable for improving the affinity between amorphous silica and a rubber component.

Further, the structure having a BET specific surface area of 100 m ² / g or more and 350 m ² / g or less is easy to obtain in a silica-carbon composite material made from one or more kinds of biomass selected from the group consisting of rice straw, rice husks and straw. It is a composition. Since these biomasses have a high ash content, many amorphous silicas can be complexed with carbon by adopting the above-mentioned constitution. Therefore, it is useful when a large amount of amorphous silica is desired to be used.

The silica-carbon composite material according to the embodiment of the present invention preferably has an average particle size (D50) of 0.1 μm or more and 10 μm or less. The average particle size (D50) of the silica-carbon composite material is not particularly limited, but for example, D50 can be adjusted according to the application by pulverizing after preparation.

According to the above configuration, the average particle size (D50) is 0.1 μm or more and 10 μm or less, the carbon portion of the silica-carbon composite material ensures reinforcing property and wear resistance, and the silica portion has low loss resistance and resistance to wear. By ensuring the wet skid property, it can be suitably used for applications such as fillers for fuel-efficient tires. From this point of view, the average particle size (D50) is more preferably 0.1 μm or more and 5 μm or less, and particularly preferably 0.1 μm or more and 3 μm or less.

The average particle size (D50) is a value measured by a laser diffraction / scattering type particle size distribution measuring device.

The silica-carbon composite material according to one embodiment of the present invention preferably has amphipathic properties. As described above, the silica-carbon composite material has an excellent affinity with the rubber component even though it contains amorphous silica. As shown in Examples described later, the mixture of silica and carbon black remained separated into two phases even when added to toluene and distilled water, whereas the silica-carbon composite was a stable emulsion. Was formed. As described above, it has been demonstrated that the silica-carbon composite material according to the embodiment of the present invention has amphipathic properties.

According to the above configuration, the affinity between silica and the rubber component can be enhanced, so that a rubber product such as a tire can be manufactured even when a silane coupling agent is not used. That is, it is possible to significantly reduce the manufacturing cost and improve the efficiency of the manufacturing process.

Further, since the silica-carbon composite material according to the embodiment of the present invention has amphipathic properties, it can be said that the contained silica retains the original hydrophilicity. Therefore, in the silica-carbon composite material according to the embodiment of the present invention, for example, the silanol group increases the adhesion friction coefficient by improving the affinity between the rubber component of the tire and the road surface wet with water. The properties due to the hydrophilicity of silica can also be sufficiently retained.

(2) Additive for Polymer Material The additive for polymer material according to one embodiment of the present invention (hereinafter, also simply referred to as “additive”) is a silica-carbon composite material according to one embodiment of the present invention. contains. The additive can be used as an additive for polymer materials such as resins, synthetic leathers, synthetic fibers, and elastomers. As the polymer material, one type may be used, or two or more types may be used.

The resin may be a thermoplastic resin or a thermosetting resin. Further, the elastomer may be a rubber component (thermocurable elastomer) or a thermoplastic elastomer (TPE). As the rubber component, for example, the rubber component shown in the section of "rubber composition" described later can be used. The thermoplastic elastomer may be any kind of thermoplastic elastomer such as styrene-based, olefin-based, vinyl chloride-based, urethane-based, ester-based, and amide-based.

Further, the additive can be used as an additive for resin or rubber if there is no problem even if it is colored black.

By adjusting the amount of the additive added and mixing it with the polymer material, the strength, heat resistance, various resistances, etc. of the polymer material can be improved. In addition, since the additive effectively utilizes biomass as a waste, it is possible to suppress the consumption of mineral resources used as the additive.

The additive can also impart a new function to the polymer material. For example, when used as an additive to a rubber composition, the content of silica in the rubber composition can be increased, so that the insulating property of the rubber composition can be improved. The additive can also improve the processability of the polymer material. Further, by using the additive as a functional extender, it is possible to reduce the manufacturing cost of rubber products and the like while maintaining excellent properties. When the additive is used as an additive for a resin product, the silica-carbon composite material contains a carbon porous body and has a small bulk specific gravity, so that there is an advantage that the product can be made lighter.

The content of the silica-carbon composite material in the additive is preferably 50% by mass or more, preferably 70% by mass or more, from the viewpoint of sufficiently exerting the effect of the silica-carbon composite material. It is more preferable that there is 90% by mass or more. The content may be 100% by mass. That is, the additive may be the silica-carbon composite material itself. Further, the content is preferably 90% by mass or less, more preferably 70% by mass or less, and particularly preferably 50% by mass or less, from the viewpoint of suppressing deterioration of other physical properties of the product. preferable.

Examples of the components that the additive can contain in addition to the silica-carbon composite material include mineral-derived amorphous silica, carbon black, calcium carbonate, clay minerals such as talc, and the like.

The amount of the additive added to the polymer material is preferably 5 phr or more and 100 phr or less, and more preferably 10 phr or more and 50 phr or less. If there is no problem even if the additive is colored black, it can be used for other purposes other than polymer materials such as cosmetics, foods, and paints.

(3) Rubber Composition The rubber composition according to the embodiment of the present invention is a rubber composition containing a rubber component and an additive for a polymer material according to the embodiment of the present invention. The content of the additive for polymer materials with respect to the components is 3 phr or more and 140 phr or less.

As described above, the additive according to the embodiment of the present invention contains the silica-carbon composite material according to the embodiment of the present invention. The silica-carbon composite material can enhance the affinity between silica and the rubber component regardless of whether a silane coupling agent is used or not. Therefore, the additive can be suitably used as a component of the rubber composition.

The rubber component is not particularly limited. For example, natural rubbers such as SIR20, RSS # 1, RSS # 3, TSR20, deproteinized natural rubber (DPNR), high-purity natural rubber (HPNR); isoprene rubber, butadiene rubber, styrene butadiene rubber, butyl rubber, butyl halide rubber, etc. Acrylonitrile butadiene rubber, acrylonitrile-styrene-butadiene copolymer rubber, chloroprene rubber, ethylene-propylene copolymer rubber, styrene-isoprene copolymer rubber, styrene-isoprene-butadiene copolymer rubber, isoprene-butadiene copolymer rubber , Chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, silicone rubber, urethane rubber and the like. These may be used alone or in combination of two or more.

Further, the rubber component may be produced by any polymerization method such as emulsion polymerization or solution polymerization, and may have a structure having a modifying group at the terminal.

In the rubber composition according to the embodiment of the present invention, the content of the additive according to the embodiment of the present invention is preferably 3 phr or more, more preferably 5 phr or more, and 10 phr or more. Is particularly preferred. When the content is 10 phr or more, the desired properties of amorphous silica and carbon can be sufficiently exhibited in a tire or the like manufactured by using the rubber composition.

In addition, "phr" is an abbreviation for parts per hungred rubber, and means a blending amount with respect to 100 parts by weight of a rubber component.

The content is preferably 140 phr or less, more preferably 120 phr or less, and particularly preferably 100 phr or less. When the content is 140 phr or less, there is a tendency that the desired properties of amorphous silica and carbon can be sufficiently exhibited while suppressing an adverse effect on molding processability due to an increase in viscosity of the rubber composition.

The rubber composition according to one embodiment of the present invention may contain a compounding agent usually used in the rubber industry in addition to the additive for polymer material and the rubber component according to one embodiment of the present invention. Examples of the compounding agent include other fillers such as carbon black, silica, calcium carbonate, clay, and talc; vulcanization promotion of sulfenamide-based vulcanization accelerator, guanidine-based vulcanization accelerator, zinc oxide, etc. Auxiliary) agent; Processing auxiliary agent such as stearic acid; Coupling agent such as silane type and titanate type; Antiaging agent such as amine type and phenol type; Reinforcing material; Softener; Plastic agent; Adhesive imparting agent; Scorch inhibitor ; Etc. can be used.

The content of the compounding agent is not particularly limited, but the total amount of the filler such as carbon black and silica is preferably 10 phr or more and 100 phr or less in the rubber composition according to the embodiment of the present invention. ..

The rubber composition according to one embodiment of the present invention contains an additive for a polymer material, a rubber component, and if necessary, the above-mentioned compounding agent according to one embodiment of the present invention, such as a Banbury type mixer, a kneader, and an open roll. It can be prepared by a method of kneading with a kneader of the above and then vulcanizing.

As shown in Examples described later, the rubber composition according to the embodiment of the present invention is equivalent in various physical properties to the rubber composition prepared by using silica, carbon black and a silane coupling agent. Shows the results of. That is, the rubber composition according to the embodiment of the present invention can be produced at low cost and can exhibit sufficient strength, rolling resistance, etc., and is therefore very suitable for rubber products such as tires. It can be said that it is a composition that can be used for.

(3) Rubber Product The rubber product according to the embodiment of the present invention contains the rubber composition according to the embodiment of the present invention. Since the rubber composition has the above-mentioned excellent properties, the rubber product can have the properties. Further, since the silica-carbon composite material according to the embodiment of the present invention does not contain silane coupling, the price of the main body of the rubber product can be reduced. That is, it can be said that the rubber product according to the embodiment of the present invention is an excellent product having both high performance and low price.

The rubber product is, for example, a method in which a rubber composition according to an embodiment of the present invention is processed by extrusion or the like in an unvulcanized state, molded by a usual method, and then heated and pressurized in a vulcanizer. It can be manufactured by such means.

Examples of the rubber product include tires, rubber crawler, anti-vibration rubber, rubber belt, rubber hose, O-ring, packing, sole, oil seal, diaphragm, rubber coating, and rubberized cloth. In order to reduce tan δ while maintaining excellent mechanical strength, these rubber products, for example, reduce fuel consumption of tires and rubber crawlers due to a decrease in rolling resistance, packing and rubber hoses due to an improvement in impact resilience, etc. It is possible to obtain the effects of maintaining the surface pressure at the connecting portion and the like, improving the anti-vibration property and the cushioning property, and the like.

[Embodiment 2: A method for producing a silica / carbon composite material according to an embodiment of the present invention]
The method for producing a silica-carbon composite material according to an embodiment of the present invention is gasification in which a part of carbon contained in the biomass is gasified by supplying superheated steam to the biomass derived from a silicic acid plant. Process and
The step includes a recovery step of recovering the biomass residue that remains as a solid content without being gasified in the gasification step as a silica-carbon composite material.

(1) Gasification Step Hereinafter, the gasification step will be described with reference to FIG. FIG. 1 is a schematic view showing an example of an outline of the configuration of a gasification furnace capable of carrying out a gasification step. The gasification furnace 100 has a two-stage cylindrical shape, and includes a gasification unit 1 and a gas reforming unit 2.

The biomass is composed of a combustible component (organic component) and an ash component (inorganic component). Further, combustibles are roughly classified into carbon and non-carbons (hydrogen, nitrogen, oxygen, etc.), and ash contains potassium and the like as trace components, but most of them are silica (SiO ₂ ). When the biomass is subjected to a gasification step, a part of carbon contained in the biomass is converted into gas (carbon monoxide and hydrogen) by the water gas reaction represented by the formula (1).
C + H ₂ O → CO + H ₂ ... (1)
At this time, almost all of the combustible components other than carbon in the biomass is transferred to the gas. Further, carbon is distributed into gas and biomass residue (gasified ash) according to the conditions of the gasification process. The biomass residue is a portion that remains as a solid content without being gasified in the gasification process. When the carbon contained in the biomass is 100% by mass, the distribution rate of carbon to the gas is the gasification rate. Most of the ash (silica) is transferred to the biomass residue. Therefore, as the gasification rate is lowered, the amount of biomass residue that can be produced from the same amount of biomass increases, and the carbon concentration in the biomass residue also increases.

As shown in FIG. 1, first, biomass derived from silicic acid plants is introduced into the gasification section 1 by a screw conveyor, and superheated steam is supplied to the gasification section 1. That is, by supplying superheated steam to the biomass derived from the silicic acid plant, a part of the carbon contained in the biomass is gasified.

The superheated steam is a gasifying agent that gasifies the biomass, and a part of carbon in the biomass is converted into carbon monoxide and hydrogen by the reaction represented by the formula (1). On the other hand, the carbon distributed in the biomass residue becomes a carbon porous body by being activated by the superheated steam, and the carbon porous body forms a complex with silica, whereby one embodiment of the present invention. It becomes a silica-carbon composite material according to.

The temperature of the superheated steam may be 100 ° C. or higher, more preferably 300 ° C. or higher. When the temperature of the superheated steam is 100 ° C. or higher, the superheated steam having a temperature corresponding to the amount of the biomass input to the gasification unit 1 can be used after adjusting the supply amount. As a result, the rate of gasification of the biomass (gasification rate) can be suitably adjusted.

By adjusting the gasification rate of the biomass, the gasification rate can be adjusted, and as a result, the specific surface area of the silica-carbon composite material can be set to the above-mentioned preferable value. As shown in Examples described later, the specific surface area of the silica-carbon composite material becomes maximum when the gasification rate is about 40% or more and 60% or less regardless of the type of biomass.

The temperature of the superheated steam is preferably 700 ° C. or lower, preferably 600 ° C. or lower, from the viewpoint of performing the gasification at a suitable rate and setting the gasification rate to about 40% or more and 60% or less. More preferably, it is particularly preferably 500 ° C. or lower. When the temperature of the superheated steam is 700 ° C. or lower, the temperature is sufficiently lower than the phase transition temperature at which silica crystallizes. Further, the residence time of the biomass in the gasification furnace 100 is as short as 30 seconds or less. Therefore, in the gasification step, the silica in the biomass is not crystallized.

When supplying the superheated steam to the gasification unit 1, it is more preferable to add an oxidizing agent together with the superheated steam. Since the water gas reaction represented by the formula (1) is an endothermic reaction, a heat source is required to maintain the internal temperature of the gasifier 100 at a predetermined value. However, by adding an oxidizing agent, the biomass is described. Part of the exothermic reaction with the oxidant. Therefore, it becomes easy to maintain the temperature inside the gasification furnace 100 at a predetermined value without inputting external energy such as electricity. It should be noted that the temperature can be maintained at a predetermined value only by supplying superheated steam, but the retention becomes easier by using an oxidizing agent.

The biomass residue rises inside the gasification section 1 together with the gas (carbon monoxide and hydrogen) generated by the gasification step. The oxidizing agent is, for example, air, oxygen, a mixture of oxygen and an inert gas, etc., and the addition thereof improves the linear velocity of the gas and shortens the residence time of the biomass residue in the gasification furnace 100. can do. The type of the inert gas is not particularly limited. The mixing ratio of oxygen and the inert gas is preferably 1: 1 to 1: 4 in volume ratio.

The atmospheric temperature at which the gasification step is performed is preferably 700 ° C. or lower, preferably 600 ° C. or lower, from the viewpoint of performing the gasification at a suitable rate and setting the gasification rate to about 40% or more and 60% or less. More preferably, it is particularly preferably 500 ° C. or lower.

The superheated steam can be obtained, for example, by heating water at a high frequency at normal pressure. Although not shown in FIG. 1, the superheated steam can be supplied to the inside of the gasification unit 1 from the tip of the nozzle of the steam supply unit provided below the gasification unit 1, for example. Further, the oxidizing agent can be supplied to the inside of the gasification unit 1 from the tip of the nozzle of the oxidizing agent supply unit provided below the gasification unit 1, for example.

The amount of the superheated steam input to the gasification section 1 is preferably 1 or more by volume with respect to the carbon amount of the biomass from the viewpoint of appropriately activating the carbon in the biomass, and is 1.25. The above is more preferable, and 1.5 or more is particularly preferable.

The amount of the oxidizing agent charged into the gasification section 1 is determined from the viewpoints of optimizing the gasification rate, optimizing the residence time of the biomass residue, and performing the gasification step in an atmosphere of a predetermined temperature. The volume ratio of oxygen in the oxidizing agent to the carbon content of the biomass is preferably 0.3 or less, more preferably 0.2 or less, and particularly preferably 0.15 or less.

(2) Recovery step In the recovery step, the silica-carbon composite material, which is the biomass residue, is recovered. The biomass residue is transferred to the gas reforming unit 2 together with the gas (carbon monoxide and hydrogen) generated by the gasification step. In the gas reforming unit 2, an aqueous gas shift reaction is performed on carbon monoxide generated in the gasification step, and the ratio of carbon monoxide to hydrogen is adjusted.

The mixture of the gas having the adjusted ratio and the biomass residue (“synthetic gas” in the figure) is discharged from the gas reforming section 2 and separated when the buoyancy of the biomass residue becomes larger than gravity. It is sent to the mechanism (not shown). Then, the biomass residue can be separated from the mixture by a separation mechanism and recovered as a silica-carbon composite material according to an embodiment of the present invention. As the separation mechanism, for example, a centrifuge cyclone or the like can be used.

Between the gasification step and the recovery step, the biomass residue obtained by the gasification step is placed in an atmosphere higher than that of the gasification step, so that the tar contained in the biomass residue is formed. It is preferable to include a tar decomposition step for decomposing. The tar decomposition step can further improve the quality of the silica-carbon composite material.

The "atmosphere higher than the gasification step" can be created by raising the temperature inside the gas reforming unit 2 by adjusting the temperature and / or supply amount of the superheated steam, adding an oxidizing agent, or the like.

From the viewpoint of not proceeding with gasification and efficiently decomposing only tar, the "atmosphere higher than the gasification step" is preferably an atmosphere of more than 700 ° C. and 800 ° C. or lower. That is, the tar decomposition step is preferably performed in an atmosphere of more than 700 ° C. and 800 ° C. or lower. When the oxidizing agent is added, the linear velocity of the gas is improved, and the residence time of the biomass residue in the gasification furnace 100 can be further shortened.

If the gasification step is performed in a high temperature atmosphere exceeding 700 ° C., the tar content remaining in the gasification step is reduced, so that the tar decomposition step can be omitted. However, in order to adjust the BET specific surface area of the silica-carbon composite material to a desired value by the gasification rate of biomass, it is preferable that the atmospheric temperature at which the gasification step is performed is low. In that case, a large amount of tar remains in the biomass residue, so it is preferable to provide a tar decomposition step.

The silica-carbon composite material according to the embodiment of the present invention can be produced by the above-mentioned production method. The fact that the silica-carbon composite material according to the embodiment of the present invention was produced is that the biomass residue obtained in the recovery step was observed by SEM to obtain a composite of amorphous silica and a carbon porous body. It can be confirmed by a method of confirming that is formed, a method of confirming that the biomass residue has an amphoteric nature as shown in Examples described later, and the like.

The silica-carbon composite material recovered by the recovery step may be pulverized as needed to adjust the average particle size (D50), and the properties as a composite are maintained even after pulverization. The crushing can be appropriately performed by a conventionally known crusher. The suitable average particle size (D50) is as described above.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

The present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited thereto.

[Example 1]
(Relationship between gasification rate and BET specific surface area of silica-carbon composite material)
In this embodiment, the biomass residue obtained by performing the gasification step in the method for producing a silica-carbon composite material according to one embodiment of the present invention under the conditions where the gasification rate is changed for various biomasses. The BET specific surface area of (silica-carbon composite material) was measured.

Rice straw, rice husks, sawdust, bamboo, or bark (bark) were charged as biomass into the gasification section 1 of the gasification furnace 100 shown in FIG. 1 by a screw conveyor. At the same time, superheated steam at 400 to 700 ° C. is blown in so that the volume ratio is 1 to 1.5 with respect to the carbon content of the biomass, and air is blown so that the volume ratio of oxygen in the air to the carbon content of the biomass is 1 to 1.5. The temperature inside the gasification unit 1 was changed to 500 to 700 ° C. by blowing the air so as to be 0.1, and the gasification rate was adjusted.

Further, air was blown into the gas reforming unit 2 so that the volume ratio of oxygen in the air to the carbon content of the biomass was 0.05. The temperature of the gas reforming unit 2 was set to 800 ° C.

Subsequently, a mixture of the gas that had undergone the water-gas shift reaction and the biomass residue was discharged from the gas reforming unit 2.

Next, the biomass residue was separated from the mixture by a centrifuge cyclone to obtain a silica-carbon composite material.

For the gasification rate, the amount and carbon concentration of the biomass to be input, and the amount and carbon concentration of the outlet gas of the cyclone (total concentration of CO, CO ₂ , and CH ₄ ) were measured for each biomass. It was calculated by the following formula (2).
Gasification rate (%) = (amount of cyclone outlet gas x carbon concentration) / (amount of biomass x carbon concentration) x 100 ... (2)
Further, the BET specific surface area of the silica-carbon composite material is measured using a laser diffraction / scattering type particle size distribution measuring device (manufactured by Microtrac Bell), and the gasification rate is taken as the horizontal axis, and the BET ratio. It was plotted on a graph with the surface area as the vertical axis.

2 and 3 are diagrams showing changes in the BET specific surface area of the silica-carbon composite material according to one embodiment of the present invention when the gasification rate is changed in the gasification step. FIG. 2 shows the results when rice straw and rice husks were used. FIG. 3 is a diagram in which the results shown in FIG. 2 and the results when sawdust, bamboo, and bark are used are added.

Unlike rice straw and rice husks, which contain about 20% by weight of ash, sawdust, bamboo, and bark have a low ash content of about several% by weight, so the ratio of carbon to the total weight is relatively high. high. Therefore, when the gasification rate is the same, the BET specific surface area is larger than that when rice straw and rice husks are used. Therefore, the vertical axis of FIG. 3 represents the BET specific surface area of the silica-carbon composite material made from rice straw and rice husks on the left side, and the silica-carbon composite material made from rice husk, bamboo and bark on the right side. It represents the BET specific surface area.

As shown in FIG. 2, when rice straw and rice husks were used as raw materials, the BET specific surface area of the silica-carbon composite material became maximum when the gasification rate was around 50% (40 to 60%). Further, as shown in FIG. 3, even when sawdust, bamboo and bark are used as raw materials, the BET specific surface area of the silica-carbon composite material becomes maximum when the gasification rate is around 50% (40 to 60%). It was.

From the above results, it was clarified that the BET specific surface area of the silica-carbon composite material can be adjusted by adjusting the gasification rate regardless of the type of biomass. The silica-carbon composite material having the BET specific surface area shown in FIGS. 2 and 3 all corresponds to the silica-carbon composite material according to the embodiment of the present invention.

[Example 2]
(Relationship between gasification rate and yield and composition of silica-carbon composite material)
As described above, as the gasification rate in the gasification step is lowered, the amount of biomass residue that can be produced from the same amount of biomass, that is, the amount of the silica / carbon composite material according to the embodiment of the present invention increases, and the amount of silica / carbon increases. The carbon concentration in the composite also increases. Therefore, in this example, changes in the yield and composition of the silica-carbon composite material when the gasification rate was changed were examined on the desk.

For the composition of rice husks, combustibles, ash, carbon concentration, silica concentration, and potassium concentration were quantitatively analyzed for rice husks collected from 10 locations nationwide, and the average value was used. The combustible content is the rate of weight loss after thinly spreading rice husks on a magnetic dish and heating at 800 ° C. for 2 hours using an electric muffle furnace, and the ash content is a value obtained by subtracting the value of the combustible component from 100. The carbon concentration was analyzed by a CHN coder, the silica concentration was analyzed by an alkaline melting-gravimetric method, and the potassium concentration was analyzed by an acid decomposition-atomic absorption method.

In each case where the gasification rate is 30 to 90%, carbon contained in the combustible component is transferred to gas at a ratio according to the gasification rate, and all elements other than carbon are transferred to gas in the gasification furnace. I decided to do it. It was assumed that all of the silica and potassium contained in the ash would be transferred to the biomass residue. The calculation was performed based on the above assumptions, and the amount and composition of the biomass residue were calculated under the condition of a gasification rate of 30 to 90%.

4 and 5 are diagrams showing the results of determining the yield and composition of the biomass residue when the gasification rate in the gasification step was changed. FIG. 4 is a diagram showing the composition of gas and biomass residue when the gasification rate is 30% to 90%, and FIG. 5 is a diagram showing the composition of rice husks and the gasification rate of 30% to 90%. It is a figure which showed the yield of the biomass residue and the composition of the biomass residue at the time.

For example, as shown in FIG. 5, when the gasification rate was 90%, the yield of the biomass residue was 235 kg per ton of rice husks, and the carbon concentration in the biomass residue was calculated to be 16% by weight. On the other hand, as the gasification rate decreases, the yield and carbon concentration increase, and when the gasification rate is 60%, the yield is 349 kg per ton of rice husks, the carbon concentration is 44%, and the gasification rate is high. In the case of 50%, the yield was calculated to be 387 kg per ton of rice husks, and the carbon concentration was calculated to be 49%.

From the above results, as the gasification rate is lowered, the amount of biomass residue that can be produced from the same amount of biomass, that is, the amount of the silica-carbon composite material according to the embodiment of the present invention increases, and the amount in the silica-carbon composite material increases. It was revealed that the carbon concentration also increased.

[Example 3]
(1) Confirmation of Complex Formation of Amorphous Silica and Carbon by SEM Silica according to an embodiment of the present invention produced using rice husk as a raw material under the condition that the gasification rate is adjusted to 70% in Example 1. -The carbon composite was observed by SEM. 6 and 7 are diagrams showing the observation results of the silica / carbon composite material which has not been pulverized by SEM. FIG. 6 shows observation results at a magnification of 100 times, and FIG. 7 shows observation results at a magnification of 500 times. Further, FIG. 8 is a diagram showing the observation results by SEM of a silica-carbon composite material having an average particle diameter (D50) of about 1 μm after being pulverized.

For the pulverization treatment, a planetary ball mill (manufactured by Fritsch) was used, and the biomass residue and agate balls having a diameter of 10 mm were filled in an agate container and pulverized for 5 minutes.

As can be seen from FIGS. 6 to 8, the silica-carbon composite material had an amorphous shape derived from the shape of rice husks as a whole. In addition, it was clearly observed that a large number of small tufted particles were agglutinated and adhered to the large lumpy particles, especially those subjected to the pulverization treatment.

(2) Mapping analysis by electron probe X-ray microanalyzer (EPMA) With respect to the pulverized silica-carbon composite material used in (1) above, the main composition of the specific portion in FIG. 8 is analyzed by mapping analysis by EPMA. investigated. As the EPMA, SEM-EPMA 8530F (manufactured by JEOL Ltd.) was used.

FIG. 9 is an SEM photograph of the large lumpy particles shown in FIG. 8 observed at a magnification of 14 times, and the portion indicated by a cross in the figure is the portion where the mapping analysis was performed. FIG. 10 shows the result of the mapping analysis of the large agglomerate particles.

Further, FIG. 11 is an SEM photograph of the small tufted particles shown in FIG. 8 observed at a magnification of 14 times, and the portion indicated by a cross in the figure is a portion where mapping analysis was performed. FIG. 12 shows the results of mapping analysis of the small tufted particles.

The measurement conditions for the mapping analysis are as shown in FIGS. 10 and 12. As shown in FIG. 10, the large lumpy particles contain a large amount of carbon (C) (75.54% by mass), and as shown in FIG. 12, the small tufted particles contain a large amount of silica (Si, O). It was found to contain 65.67% by mass). However, neither the large agglomerate particles nor the small tufted particles were composed of a single component of carbon or silica. That is, it was confirmed that both the large agglomerate particles and the small tufted particles were particles in which carbon and amorphous silica formed a complex.

[Example 4]
(Regarding the amphipathic nature of the silica-carbon composite material according to one embodiment of the present invention)
In this example, it was confirmed that the silica-carbon composite material according to the embodiment of the present invention has amphipathic properties.

As the silica-carbon composite material according to the embodiment of the present invention, a silica-carbon composite material containing 45% by mass of carbon and 55% by mass of amorphous silica prepared from rice husks was used. The composition was determined by the mapping analysis described above.

Two screw tubes (volume 13.5 ml) were prepared, and 5 ml of toluene and 5 ml of distilled water were added to both screw tubes. Then, 0.1 g of the silica-carbon composite material was added to one of the screw tubes. To the other screw tube, 0.0055 g of commercially available silica (Zeosil 1165MP manufactured by Rhodia) and 0.045 g of commercially available carbon black (ASTM code: N220) were added for comparison. That is, the silica-carbon composite material has the same composition as that of the comparison target. Next, each screw tube was exposed to ultrasonic waves for 10 minutes and then allowed to stand for 1 day.

The results are shown in Table 1 and FIG. FIG. 13 is a diagram showing that the silica-carbon composite material according to the embodiment of the present invention has amphipathic properties, and the left side is a screw to which the silica-carbon composite material according to the embodiment of the present invention is added. It is a pipe, and the right side is the screw pipe to be compared.

When the silica-carbon composite material according to the embodiment of the present invention was used, the toluene and distilled water remained in an emulsion state even after being allowed to stand for one day. On the other hand, in the comparison target, the liquid was separated into two phases, the hydrophilic silica was separated into the aqueous phase (lower phase), and the hydrophobic carbon black was separated into the oil phase (upper phase). From this result, the silica-carbon composite material according to the embodiment of the present invention is not a mere mixture of silica and carbon, but a composite of amorphous silica and carbon, whereby a parent medium is formed. It became clear that it showed sex.

[Example 5]
(Physical properties of the rubber composition according to one embodiment of the present invention)
(1) Preparation of rubber composition, etc. In this example, the components shown in Table 2 are used in the compositions shown in Table 2 and kneaded to prepare a test piece of the rubber composition according to the embodiment of the present invention. Various physical properties were measured.

The "silica-carbon composite material" in the table is a silica-carbon composite material according to an embodiment of the present invention, which is produced from rice husks as a raw material under the condition that the gasification rate is adjusted to 70% in Example 1. , "1 μm", "3 μm", and "5 μm" are the average particle diameter (D50) of the silica-carbon composite material. The average particle size (D50) is a value measured by a laser diffraction / scattering type particle size distribution measuring device (manufactured by Microtrac Bell). Nipsil VN-3 is a conventionally known silica. The numerical values in Table 2 are parts by weight of each component with respect to 100 parts by weight of RSS # 1 (natural rubber). “Ratio 1” and the like indicate that the composition for comparison used in Comparative Example 1 and the like is compounded, and “Fruit 1” and the like indicate that the rubber composition used in Example 1 and the like are compounded.

The rubber composition of the example was prepared as follows. For the following kneading and kneading, a lab blast mill Banbury type mixer B600 (manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used. First, natural rubber was kneaded for 20 seconds. Next, the silica-carbon composite material, antiaging agent, microcrystalline wax and stearic acid according to one embodiment of the present invention were added to the kneaded natural rubber and kneaded for 30 seconds. As shown in Table 2, in Examples 1 to 3, 7 and 9, a silane coupling agent was also added.

Carbon black was added to the obtained kneaded product, kneaded for 30 seconds, cleaned, and then kneaded for another 30 seconds. The obtained kneaded product was cleaned again, kneaded for 60 seconds or more while heating to 160 ° C. ± 3 ° C., and discharged from the mixer. The obtained kneaded product was designated as kneaded product 1.

The initial set temperature of the mixer at the time of preparing the kneaded product 1 was 80 ° C., and the rotor rotation speed was 60 to 100 rpm.

The kneaded product 1 was passed through a roll and then cooled at room temperature. Then, zinc oxide, sulfur and a vulcanization accelerator were added to the kneaded product 1, kneaded for 90 seconds or more while heating to 115 ° C. ± 3 ° C., and discharged from the mixer. The obtained kneaded product was designated as kneaded product 2.

The initial set temperature of the mixer at the time of preparing the kneaded product 2 was 80 ° C., and the rotor rotation speed was 40 to 100 rpm. The compounding ratio is the same as when the kneaded product 1 is prepared.

In Comparative Example 1, silica and a silane coupling agent were used instead of the silica-carbon composite material according to the embodiment of the present invention, and in Comparative Example 2, the silica-carbon composite material according to the embodiment of the present invention was used. Instead of, only carbon black was used.

The kneaded product 2 was press-molded at a press temperature of 160 ° C. for the press time shown in Table 3 using an electric heat press machine manufactured by Otake Machinery Co., Ltd. to prepare a test piece.

In the table, "wear test piece" indicates the press time of the test piece used in the pain effect measurement test described later, and "2 mmt sheet" indicates the press time of the test piece used in the durometer hardness test.

(2) Measurement of Physical Properties Next, the tests shown in (a) to (f) below were performed using the prepared test pieces.

(A) Vulcanization degree test Based on JIS K 6300-2: 2001 "Unvulcanized rubber-Physical properties-Part 2: How to obtain vulcanization characteristics with a vibration type vulcanization tester", vulcanization under the following conditions A degree test was conducted.

<Test conditions>
Test method: Die vulcanization test method A (torsion vibration flat plate die vulcanization test)
Test temperature: 160 ° C
Test time: 30 minutes Amplitude angle: ± 1 °
Frequency: 1.67Hz (100cpm)
Testing machine used: Vulcanization degree testing machine (FDR) VR3110 manufactured by Ueshima Seisakusho Co., Ltd.
(B) Mooney Viscosity Test Based on JIS K 630-1: 2005 "Unvulcanized Rubber-Physical Properties-Part 1: How to Obtain Viscosity and Scorch Time with Mooney Viscometer", Mooney Viscosity was measured under the following conditions. ..

<Test conditions>
Test temperature: 100 ° C
Rotor type: L type Testing machine: Shimadzu Co., Ltd. Shimadzu Mooney Biscomeota SMV-301RT
(C) Durometer hardness test Based on JIS K 6253-: 2012 "Vulcanized rubber and thermoplastic rubber-How to determine hardness-Part 3: Durometer hardness", a durometer hardness test is performed under the following conditions. It was.

<Test conditions>
Specimen preparation method: After producing a sheet by press molding, punching process Specimen shape: Sheet shape (three test pieces with a thickness of about 2 mm are laminated)
Test equipment: Ascar rubber hardness tester (durometer) A type (d) Tensile test manufactured by Polymer Meter Co., Ltd. Based on JIS K 6251: 2010 "Vulcanized rubber and thermoplastic rubber-How to determine tensile properties", under the following conditions A tensile test was performed.

<Test conditions>
Specimen preparation method: After producing a sheet by press vulcanization, punching process Specimen shape: Dumbbell-shaped No. 3 Specimen collection direction: Parallel to the column Number of test pieces: 3
Measurement temperature: 23 ° C
Test speed: 500 mm / min
Testing machine used: Shimadzu Corporation Precision universal testing machine Autograph EZ-LX 1kN
Testing machine capacity: Load cell type 1kN
(E) Tear test Based on JIS K 6252: 2007 "Vulcanized rubber and thermoplastic rubber-How to determine tear strength", a tear test was performed under the following conditions.

<Test conditions>
Specimen preparation method: After producing a sheet by press molding, punching Specimen shape: Angle type without cuts Specimen collection direction: Vertical to the column Number of test pieces: 5
Test temperature: 23 ° C
Test speed: 500 mm / min
Testing machine used: Shimadzu Corporation Precision universal testing machine Autograph EZ-LX 1kN
Testing machine capacity: Load cell type 1kN
(F) Measurement of Pain effect after vulcanization
Based on ISO 13145: 2012 "Rubber --Determination of viscosity and stress relaxation using a rotorless sealed shear rheometer", the pain effect after vulcanization was measured under the following conditions.

<Test conditions>
Measurement items: Dynamic shear storage elastic modulus G', dynamic shear loss elastic modulus G'', loss tangent tan δ
Testing machine used: ALPHA TECHNOLOGIES RPA2000
Measurement program: Shown in Table 4. The measurement of the dynamic strain under the condition 4 was completed when the torque was over.

The results are shown in Table 5. In Comparative Example 1, amorphous silica and carbon black are blended with natural rubber, and at that time, a silane coupling agent is used in order to improve the affinity of amorphous silica with natural rubber. That is, the composition used in Comparative Example 1 is a composition in which amorphous silica is blended with a rubber component by a method widely used in the past.

In the table, the "minimum torque" of the vulcanization degree test is an index of the viscosity of the rubber composition, and the "maximum torque" is an index of the strength of the rubber composition. Further, T10 indicates the easiness of solidification of the rubber composition, which is an index of processing safety and productivity, and indicates that production is difficult if it is too short. Further, the longer T10 is, the more difficult it is to start vulcanization. T90 indicates the molding time of the rubber composition.

Mooney viscosity is an index of processability of the rubber composition, and it can be said that the smaller the value, the easier the processability. The durometer hardness is an index of the hardness of the rubber composition, and it can be said that the larger the value, the higher the strength. Tb × Eb in the tensile test is the product of tensile strength and elongation. The tensile product means the breaking energy of the rubber composition, and the larger the amount, the larger the energy for breaking the rubber composition. M100 is the stress required to stretch the rubber composition 100%, and M300 is the stress required to stretch the rubber composition 300%. M300 / M100 is an index of the dispersibility of the filler with respect to the rubber component, and the larger the value, the better the dispersibility.

The tear strength is an index showing how hard the rubber composition is to tear when stress is concentrated on the rubber composition. The Pain effect is an index of fuel efficiency when the rubber composition is used for a tire, and the smaller the value, the higher the fuel efficiency.

Examples 1 to 3 are the silica-carbon composite material according to the embodiment of the present invention to which a silane coupling agent is added, and Examples 4 to 6 are carried out without adding the silane coupling agent. The same silica-carbon composite material as in Examples 1 to 3 is used. Further, Examples 7 and 8, and Examples 9 and 10 also correspond to the case where the silane coupling agent is added and the case where the silane coupling agent is not added.

As can be seen from Table 5, the test results of Examples 1 to 3 and 7 and 9 were equivalent to those of Comparative Example 1. In addition, the test results of Examples 4 to 6, 8 and 10 were equivalent to those of Examples 1 to 3, 7 and 9, respectively.

In Examples 1 to 3 and Examples 4 to 6, the blending amount of the silica / carbon composite material was changed, respectively, but even if the blending amount was increased, the tensile strength did not decrease significantly. It was. Further, the tensile strength showed a value higher than that of Comparative Example 1 in Examples 1 and 4 in which the blending amount was 10 parts by weight.

That is, the silica-carbon composite material according to the embodiment of the present invention can exhibit strength equal to or higher than that of the conventional rubber composition using amorphous silica, and has a rubber composition such as a pain effect. It was clarified that the characteristics required for an object can be sufficiently exhibited. In particular, as can be seen from the results of Examples 4 to 6, 8 and 10, when the silica-carbon composite material according to the embodiment of the present invention is used, the strength and characteristics are obtained without using a silane coupling agent. Satisfactory results have been obtained.

If the silica-carbon composite is merely a mixture of silica and carbon, the affinity of silica with carbon decreases in the absence of the silane coupling agent, and thus Examples 4 to 6, 8 and It is considered that a result like 10 cannot be shown. That is, the results of Examples 4 to 6, 8 and 10 show that in the silica-carbon composite material, amorphous silica and carbon do not simply exist in a mixed state, but form a composite. It can be said that it is based.

The present invention can be suitably used for rubber products such as tires.

1 Gasification section 2 Gas reforming section 100 Gasification furnace

Claims (11)

Silica-Carbon composite material that uses biomass derived from silicic acid plants as a raw material and contains a composite of amorphous silica and a carbon porous body. The silica-carbon composite material according to claim 1, which contains 10% by mass or more and 70% by mass or less of carbon contained in the biomass. The silica-carbon composite material according to claim 1 or 2, wherein the BET specific surface area is 100 m ² / g or more and 900 m ² / g or less. The silica-carbon composite material according to claim 3, wherein the BET specific surface area is 100 m ² / g or more and 350 m ² / g or less. The silica-carbon composite material according to any one of claims 1 to 4, wherein the average particle size (D50) is 0.1 μm or more and 10 μm or less. The silica-carbon composite material according to any one of claims 1 to 5, which has amphipathic properties. An additive for a polymer material containing the silica-carbon composite material according to any one of claims 1 to 6. A rubber composition containing a rubber component and the additive for a polymer material according to claim 7, wherein the content of the additive for a polymer material with respect to the rubber component is 3 phr or more and 140 phr or less. Composition. A rubber product containing the rubber composition according to claim 8. A gasification step of gasifying a part of carbon contained in the biomass by supplying superheated steam to the biomass derived from silicic acid plants.
A method for producing a silica-carbon composite material, which comprises a recovery step of recovering a biomass residue that remains as a solid content without being gasified in the gasification step as a silica-carbon composite material. By placing the biomass residue obtained by the gasification step in an atmosphere higher than that of the gasification step between the gasification step and the recovery step, tar contained in the biomass residue can be obtained. The method for producing a silica-carbon composite material according to claim 10, further comprising a tar decomposition step of decomposing.