Method for manufacturing a carrier and carrier

Abstract

To provide a method for producing a carrier that can readily produce a carrier having microfibrillated vegetable fiber on inorganic powder, a carrier, a rubber composition and a tire.SOLUTION: A method for producing a carrier includes a step 1 for mixing microfibrillated vegetable fiber, a plasticizer having an epoxy group and water to make a mixture 1, a step 2 for adjusting the pH of the mixture 1 to 10.0 or more and then adjusting the pH to 6.0-7.0, making a mixture 2, and a step 3 for spraying inorganic powder with the mixture 2, followed by drying, to make a carrier having the microfibrillated vegetable fiber on the inorganic powder.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a carrier, a carrier, a rubber composition, and a tire. [Background technology]

[0002] As a method for dispersing fillers such as inorganic powders like silica or microfibrillated plant fibers like cellulose fibers into polymers such as rubber, the wet masterbatch method (WMB method) has been proposed. For example, it involves mixing a water-dispersed slurry of fillers with rubber latex, and then coagulating, dehydrating, and drying it to produce a composite. However, the WMB method has drawbacks, such as high transportation and manufacturing costs. [Overview of the project] [Problems that the invention aims to solve]

[0003] The present invention aims to solve the above-mentioned problems and provide a method for manufacturing a carrier, a carrier, a rubber composition, and a tire that can easily produce a carrier in which microfibrillated plant fibers are attached to an inorganic powder. [Means for solving the problem]

[0004] The present invention comprises a step 1 of mixing microfibrillated plant fibers, a plasticizer having epoxy groups, and water to produce a mixture 1, Step 2 involves adjusting the pH of the aforementioned mixture 1 to 10.0 or higher, and then adjusting the pH to 6.0-7.0 to produce mixture 2. The present invention relates to a method for producing a carrier, which includes step 3 of spraying the mixture 2 onto an inorganic powder and drying it to produce a carrier in which microfibrillated plant fibers are attached to the inorganic powder.

[0005] In step 1, it is preferable that an aqueous solution of microfibrillated plant fibers containing 0.1 to 20% by mass of microfibrillated plant fibers is used and mixed using a homogenizer.

[0006] The plasticizer preferably contains epoxidized vegetable oil.

[0007] The inorganic powder preferably contains silica particles.

[0008] It is preferable that the silica particles include aggregates of silica particles.

[0009] The aggregates of silica particles are preferably granular and / or micropearl-shaped.

[0010] In step 1, it is preferable that the amount of plasticizer having epoxy groups added is 50 to 200 parts by mass per 100 parts by mass (solid content) of the microfibrillated plant fiber.

[0011] In step 3, it is preferable that the amount of microfibrillated plant fiber added is 30 to 100 parts by mass per 100 parts by mass of the inorganic powder.

[0012] Step 3 is preferably carried out by spraying the mixture 2 onto the inorganic powder that has been fluidized in a fluidized bed dryer and then drying it.

[0013] The present invention relates to a carrier in which microfibrillated plant fibers are attached to an inorganic powder, This invention relates to a carrier in which the inorganic powder and the microfibrillated plant fibers dissociate when stress is applied.

[0014] Preferably, the support has a inorganic powder content of 30.0 to 99.0% by mass and a microfibrillated plant fiber content of 1.0 to 70.0% by mass in 100% by mass of the support.

[0015] The support is preferably a powder with an average particle size of 100 μm or less.

[0016] Preferably, the support body satisfies the following formula in terms of the average fiber diameter of the microfibrillated plant fibers and the average particle diameter of the inorganic powder. Average particle diameter of inorganic powder / average fiber diameter of microfibrillated plant fiber < 0.50

[0017] The carrier is preferably an additive for a rubber composition or a resin composition.

[0018] The present invention relates to a rubber composition for tires obtained by mixing the carrier and a rubber component.

[0019] The present invention relates to a tire provided with a member made of the rubber composition.

Effect of the Invention

[0020] The present invention includes Step 1 of preparing Mixture 1 by mixing microfibrillated plant fiber, a plasticizer having an epoxy group, and water; Step 2 of adjusting the pH of Mixture 1 to 10.0 or higher and then adjusting the pH to 6.0 - 7.0 to prepare Mixture 2; and Step 3 of spraying and drying Mixture 2 onto inorganic powder to prepare a carrier on which microfibrillated plant fiber adheres to the inorganic powder. Therefore, a carrier on which microfibrillated plant fiber adheres to inorganic powder can be easily manufactured.

Mode for Carrying Out the Invention

[0021] <Manufacturing Method of Carrier> The present invention is a manufacturing method of a carrier, which includes Step 1 of preparing Mixture 1 by mixing microfibrillated plant fiber, a plasticizer having an epoxy group, and water; Step 2 of adjusting the pH of Mixture 1 to 10.0 or higher and then adjusting the pH to 6.0 - 7.0 to prepare Mixture 2; and Step 3 of spraying and drying Mixture 2 onto inorganic powder to prepare a carrier on which microfibrillated plant fiber adheres to the inorganic powder. Despite being a simple manufacturing method, the manufacturing method can favorably manufacture a carrier on which microfibrillated plant fiber adheres to inorganic powder.

[0022] The mechanism by which such an effect is obtained is not clear, but it is presumed as follows. First, in step 1, microfibrillated plant fibers with strong cohesive force are mixed with a plasticizer containing epoxy groups. Then, in the subsequent step 2, the pH of mixture 1 obtained in step 1 is adjusted to 10.0 or higher, which causes interaction between the OH groups of the microfibrillated plant fibers and the epoxy groups of the plasticizer. Further adjustment of the pH to 6.0-7.0 for neutralization is thought to produce mixture 2 in which the aggregation of microfibrillated plant fibers is prevented. Then, in the subsequent step 3, the mixture 2 containing the microfibrillated plant fibers in a state where aggregation is prevented and the plasticizer containing epoxy groups is sprayed onto an inorganic powder, and further drying is thought to produce a carrier in which microfibrillated plant fibers are attached to the surface of the inorganic powder. Therefore, despite such a simple manufacturing method, it is presumed that it is possible to produce a carrier in which microfibrillated plant fibers are attached to an inorganic powder. Furthermore, because such a support has low cohesive force, when the support is mixed with rubber or resin, inorganic powders and microfibrillated plant fibers tend to break apart easily, and it is presumed that compositions with excellent filler dispersibility can be easily produced.

[0023] (Process 1) In step 1, microfibrillated plant fibers, a plasticizer having epoxy groups, and water are mixed to produce a mixture 1 containing microfibrillated plant fibers and a plasticizer having epoxy groups.

[0024] As microfibrillated plant fibers, cellulose microfibrils are preferred from the viewpoint of fracture strength, abrasion resistance, etc. The cellulose microfibrils are not particularly limited as long as they are derived from natural products, and examples include resource biomass such as fruits, grains, and root vegetables; wood, bamboo, hemp, jute, and kenaf, as well as waste biomass such as pulp, paper, cloth, agricultural residues, food waste, and sewage sludge obtained from these raw materials, unused biomass such as rice straw, wheat straw, and thinned wood, and cellulose produced by sea squirts, acetic acid bacteria, etc. One type of microfibrillated plant fiber may be used, or two or more types may be used in combination.

[0025] In this specification, cellulose microfibrils typically refer to cellulose fibers having an average fiber diameter of several tens of μm (20-30 μm or less, preferably 10 μm or less), and more typically, cellulose fibers having a microstructure with an average fiber diameter of 500 nm or less formed by an aggregate of cellulose molecules (microfibrillated plant fibers with an average fiber diameter of several tens of μm or less, 10 μm or less, or 500 nm or less). Typical cellulose microfibrils can be formed, for example, as aggregates of cellulose fibers having the average fiber diameter described above.

[0026] There are no particular limitations on the method for producing microfibrillated plant fibers, but examples include chemically treating the cellulose microfibril raw material with an alkali such as sodium hydroxide as needed, and then mechanically grinding or beating it using a refiner, twin-screw kneader (twin-screw extruder), twin-screw kneading extruder, high-pressure homogenizer, media stirring mill, millstone, grinder, vibratory mill, sand grinder, etc. In these methods, lignin is separated from the raw material by chemical treatment, so microfibrillated plant fibers that are substantially free of lignin are obtained. In addition, other methods include treating the cellulose microfibril raw material with ultra-high pressure.

[0027] As microfibrillated plant fibers, products from companies such as Sugino Machine Co., Ltd. and Daicel Finechem Co., Ltd. can be used.

[0028] Furthermore, as mentioned above, unmodified microfibrillated plant fibers obtained by the above manufacturing methods can be sufficiently oriented within the polymer. However, in addition to unmodified microfibrillated plant fibers, those that have undergone oxidation treatment or various chemical modification treatments can also be used, as well as natural materials that can be the source of cellulose microfibrils (for example, wood, pulp, bamboo, hemp, jute, kenaf, agricultural waste, cloth, paper, sea squirt cellulose, etc.) that have been treated with oxidation treatment or various chemical modification treatments, followed by defibration treatment as necessary (chemically modified microfibrillated plant fibers, etc.).

[0029] Examples of chemical modification of microfibrillated plant fibers include esterification, etherification, and acetalization. Specifically, preferred examples include acylation such as acetylation, cyanoethylation, amination, sulfone esterification, phosphate esterification, alkyl esterification, alkyl etherification, complex esterification, β-ketoesterification, alkylation such as butylation, and chlorination. Furthermore, alkylcarbamate and arylcarbamate can also be exemplified.

[0030] Chemically modified microfibrillated plant fibers are preferably chemically modified so that the degree of substitution is within the range of 0.2 to 2.5. Here, the degree of substitution refers to the average number of hydroxyl groups per glucose ring unit that have been substituted with other functional groups by chemical modification among the hydroxyl groups of cellulose, and the theoretical maximum value is 3. The degree of substitution is more preferably within the range of 0.3 to 2.5, even more preferably within the range of 0.5 to 2.3, and particularly preferably within the range of 0.5 to 2.0. When the above chemically modified microfibrillated plant fibers consist of two or more combinations, the degree of substitution is calculated as the average of all chemically modified microfibrillated plant fibers.

[0031] The degree of substitution in chemically modified microfibrillated plant fibers can be confirmed, for example, by titration using 0.5N-NaOH and 0.2N-HCl, or by measurements such as NMR and infrared absorption spectroscopy.

[0032] Examples of suitable chemically modified microfibrillated plant fibers include amination microfibrillated plant fibers with a degree of substitution in the range of 0.3 to 2.5. The degree of substitution is preferably 0.3 to 2.3, more preferably 0.5 to 2.3, even more preferably 0.7 to 2.0, and particularly preferably 0.9 to 1.8.

[0033] When chemically modified microfibrillated plant fibers are acetylated microfibrillated plant fibers, the degree of substitution is preferably within the range of 0.3 to 2.5; when sulfone esterified microfibrillated plant fibers, the degree of substitution is preferably within the range of 0.3 to 1.8; when alkyl esterified microfibrillated cellulose, the degree of substitution is preferably within the range of 0.3 to 1.8; when complex esterified microfibrillated cellulose, the degree of substitution is preferably within the range of 0.4 to 1.8; when β-ketoesterified microfibrillated cellulose, the degree of substitution is preferably within the range of 0.3 to 1.8; when alkyl carbamate-treated microfibrillated cellulose, the degree of substitution is preferably within the range of 0.3 to 1.8; and when aryl carbamate-treated microfibrillated cellulose, the degree of substitution is preferably within the range of 0.3 to 1.8.

[0034] Acetylation can be carried out, for example, by reacting microfibrillated plant fibers with acetic acid, concentrated sulfuric acid, or acetic anhydride. Specifically, it can be carried out by conventionally known methods, such as reacting microfibrillated plant fibers with acetic anhydride in a mixed solvent of acetic acid and toluene in the presence of a sulfuric acid catalyst to carry out the acetylation reaction, and then replacing the solvent with water.

[0035] Amination can be carried out by, for example, an oxidation treatment using an N-oxyl compound such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), followed by a reaction with an amine compound (for example, a primary amine compound having 1 to 30 carbon atoms such as oleylamine (preferably a primary amine compound having 3 to 25 carbon atoms with saturated or unsaturated bonds, more preferably a primary amine compound having 6 to 23 carbon atoms with unsaturated bonds, and even more preferably a primary amine compound having 10 to 20 carbon atoms with unsaturated double bonds)) or a quaternary alkylammonium salt (preferably a quaternary alkylammonium salt having 1 to 30 carbon atoms, more preferably a quaternary alkylammonium halide having 1 to 20 carbon atoms such as hexadecyltrimethylammonium chloride) to perform a nucleophile substitution reaction, or by known methods such as tosyl esterification.

[0036] Sulfonation can be carried out by a simple procedure, for example, dissolving microfibrillated plant fibers in sulfuric acid and immersing them in water. Other methods include treatment with anhydrous sulfuric acid gas or treatment with chlorosulfonic acid and pyridine.

[0037] Phosphate esterification can be carried out, for example, by treating microfibrillated plant fibers, which have been treated with dimethylamine or the like, with phosphoric acid and urea.

[0038] Alkyl esterification can be carried out, for example, by the Schotten-Baumann process, in which microfibrillated plant fibers are reacted with carboxylic acid chlorides under basic conditions, while alkyl etherification can be carried out by the Williamson process, etc., in which microfibrillated plant fibers are reacted with alkyl halides under basic conditions.

[0039] Chlorination can be carried out, for example, by adding thionyl chloride in DMF (dimethylformamide) and heating it.

[0040] Complex esterification can be carried out, for example, by reacting microfibrillated plant fibers with two or more carboxylic acid anhydrides or carboxylic acid chlorides under basic conditions.

[0041] β-ketoesterification can be carried out, for example, by reacting microfibrillated plant fibers with diketene or alkylketene dimers, or by transesterification of microfibrillated plant fibers with β-ketoester compounds such as alkylacetate.

[0042] Alkylcarbamate can be carried out, for example, by reacting microfibrillated plant fibers with an alkyl isocyanate in the presence of a basic catalyst or a tin catalyst.

[0043] Aryl carbamate can be carried out, for example, by reacting microfibrillated plant fibers with an aryl isocyanate in the presence of a basic catalyst or a tin catalyst.

[0044] The epoxy-containing plasticizer used in step 1 is a material having epoxy groups and exhibiting plasticizing properties. Suitable epoxy-containing plasticizers include epoxides of vegetable oils and epoxides of unsaturated fatty acids, with epoxides of vegetable oils being more preferred.

[0045] Examples of epoxidized vegetable oils and epoxidized unsaturated fatty acids include epoxidized unsaturated triglycerides and epoxidized unsaturated fatty acid monoesters. Specifically, these include epoxidized vegetable oils (epoxidized soybean oil, epoxidized linseed oil, epoxidized sunflower oil, etc.), epoxidized unsaturated fatty acid octyl esters, epoxidized unsaturated fatty acid decyl esters, and epoxidized unsaturated fatty acid butyl esters.

[0046] The amount of oxirane oxygen in the epoxy group-containing plasticizer is not particularly limited, but from the viewpoint of interaction between the hydroxyl groups of the microfibrillated plant fibers and the epoxy groups of the plasticizer, it is preferably 4.0% by mass or more, more preferably 5.5% by mass or more, even more preferably 6.5% by mass or more, and particularly preferably 7.0% by mass or less. The upper limit is not particularly limited, but is preferably 15.0% by mass or less, more preferably 12.0% by mass or less, and even more preferably 10.0% by mass or less. The amount of oxirane oxygen is measured based on a standard lipid analysis test method in which the sample is dissolved in glacial acetic acid, titrated with a hydrobromic acid-glacial acetic acid solution, and the amount of oxirane oxygen contained in the sample is determined.

[0047] The water that can be used in step 1 is not particularly limited, and examples include tap water, ion-exchanged water (deionized water), and distilled water. These may be used individually or in combination of two or more. Among these, ion-exchanged water is preferred. Water can be incorporated in various ways, such as being added separately as a material other than microfibrillated plant fibers and plasticizers having epoxy groups, or being incorporated as a material contained in the microfibrillated plant fiber aqueous solution described later, but it is most preferable to incorporate it as a material contained in the microfibrillated plant fiber aqueous solution.

[0048] In the preparation of mixture 1 containing microfibrillated plant fibers, an epoxy-containing plasticizer, and water in step 1, from the viewpoint of obtaining a more effective result, it is desirable to mix the microfibrillated plant fibers with the other materials in the form of an aqueous solution dispersed in water (aqueous solution of microfibrillated plant fibers).

[0049] Aqueous solutions of microfibrillated plant fibers can be produced by known methods, for example, by dispersing microfibrillated plant fibers in water using a homogenizer (high-speed homogenizer, ultrasonic homogenizer, etc.), colloid mill, blender mill, etc. The temperature and time during preparation can be appropriately set to ensure that the microfibrillated plant fibers are sufficiently dispersed in the water.

[0050] The content (solids) of microfibrillated plant fibers in the aqueous solution of microfibrillated plant fibers is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and also preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 3.0% by mass or less, and particularly preferably 1.0% by mass or less.

[0051] Step 1, which involves mixing microfibrillated plant fibers, an epoxy-group-containing plasticizer, and water to produce a mixture 1 containing these components, can be carried out by known mixing methods. For example, the mixture 1 can be prepared by mixing and dispersing the microfibrillated plant fibers, the epoxy-group-containing plasticizer, and water using known methods such as a self-rotating mixing apparatus, a homogenizer (high-speed homogenizer, ultrasonic homogenizer, etc.), a colloid mill, or a blender mill. The temperature and time during preparation can be appropriately set within the range normally used to ensure sufficient dispersion of the microfibrillated plant fibers, or adjusted as appropriate while measuring the viscosity to achieve the desired viscosity of the mixture. For example, the temperature is preferably 5 to 80°C, more preferably 10 to 50°C, and even more preferably 12 to 40°C.

[0052] In step 1, which involves mixing microfibrillated plant fibers, a plasticizer having epoxy groups, and water, from the viewpoint of obtaining a better effect, the amount of plasticizer having epoxy groups added per 100 parts by mass (solid content) of microfibrillated plant fibers is preferably in the range of 10 to 300 parts by mass. The lower limit is more preferably 50 parts by mass or more, even more preferably 70 parts by mass or more, and particularly preferably 80 parts by mass or more. The upper limit is more preferably 200 parts by mass or less, even more preferably 150 parts by mass or less, and particularly preferably 120 parts by mass or less.

[0053] In step 1, it is preferable to adjust the solid content of mixture 1 (100% by mass) to 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more. There is no particular upper limit, but it is preferably 20.0% by mass or less, more preferably 10.0% by mass or less, even more preferably 3.0% by mass or less, and especially preferably 1.0% by mass or less.

[0054] (Process 2) In step 2, the pH of mixture 1 obtained in step 1 is adjusted to 10.0 or higher, and then the pH is adjusted to 6.0-7.0 to produce mixture 2 containing microfibrillated plant fibers and a plasticizer having epoxy groups.

[0055] The pH of mixture 1 is adjusted to 10.0 or higher, but from the viewpoint of the interaction between the microfibrillated plant fibers and the plasticizer having epoxy groups, the pH is preferably 10.5 or higher, more preferably 11.0 or higher, even more preferably 11.5 or higher, and particularly preferably 12.0 or higher. There is no particular upper limit, but it is preferably 14.0 or lower, more preferably 13.5 or lower, even more preferably 13.0 or lower, and particularly preferably 12.5 or lower.

[0056] Adjusting the pH to 10.0 or higher can be done using known methods, such as adding a basic compound to mixture 1 and mixing (stirring, etc.) as needed. Addition and mixing can be done using known methods, such as the same method as the mixing method in step 1.

[0057] The basic compound is not particularly limited, but basic inorganic compounds are preferred. Examples of basic inorganic compounds include metal hydroxides such as alkali metal hydroxides and alkaline earth metal hydroxides; metal carbonates such as alkali metal carbonates and alkaline earth metal carbonates; metal bicarbonates such as alkali metal bicarbonates; metal phosphates such as alkali metal phosphates; metal acetates such as alkali metal acetates; metal hydrides such as alkali metal hydrides; and ammonia.

[0058] Examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of alkaline earth metal hydroxides include magnesium hydroxide, calcium hydroxide, and barium hydroxide. Examples of alkali metal carbonates include lithium carbonate, sodium carbonate, and potassium carbonate. Examples of alkaline earth metal carbonates include magnesium carbonate, calcium carbonate, and barium carbonate. Examples of alkali metal bicarbonates include lithium bicarbonate, sodium bicarbonate, and potassium bicarbonate. Examples of alkali metal phosphates include sodium phosphate and sodium hydrogen phosphate. Examples of alkali metal acetates include sodium acetate and potassium acetate. Examples of alkali metal hydrides include sodium hydride and potassium hydride.

[0059] Among these, metal hydroxides, metal carbonates, metal bicarbonates, metal phosphates, and ammonia are preferred, metal hydroxides are more preferred, and sodium hydroxide and potassium hydroxide are even more preferred. The above basic compounds may be used individually or in combination of two or more.

[0060] From the viewpoint of promoting the reaction between the OH groups of the microfibrillated plant fibers and the epoxy groups of the plasticizer, when adjusting the pH of mixture 1 to 10.0 or higher, the temperature is preferably 5 to 80°C, more preferably 10 to 50°C, and even more preferably 15 to 35°C. The processing time (reaction time) at pH 10.0 or higher is usually 1 minute or more, preferably 10 minutes to 48 hours, more preferably 1 to 24 hours, and even more preferably 3 to 16 hours.

[0061] After adjusting the pH of mixture 1 to 10.0 or higher, the pH is subsequently adjusted to 6.0-7.0. From the viewpoint of neutralization, the lower limit of the pH is preferably 6.1 or higher, more preferably 6.2 or higher, and even more preferably 6.3 or higher. The upper limit is preferably 6.9 or lower, more preferably 6.8 or lower, and even more preferably 6.7 or lower.

[0062] The pH can be adjusted to 6.0-7.0 using known methods, for example, by adding an acidic compound to mixture 1 after it has been adjusted to a pH of 10.0 or lower. Mixing (such as stirring) may also be performed as needed. Addition and mixing can be carried out using known methods, for example, a method similar to the mixing method in step 1 can be used.

[0063] The acidic compounds are not particularly limited and include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, polyphosphate, metaphosphate, boric acid, boronic acid, sulfanilic acid, sulfamic acid; formic acid, acetic acid, glycolic acid, oxalic acid, propionic acid, malonic acid, succinic acid, adipic acid, maleic acid, malic acid, tartaric acid, citric acid, benzoic acid, phthalic acid, isophthalic acid, glutaric acid, gluconic acid, lactic acid, aspartic acid, glutamic acid, salicylic acid, methanesulfonic acid, itaconic acid, benzenesulfonic acid, toluenesulfonic acid, naphtha. Examples of organic acids include disulfonic acid, trifluoromethanesulfonic acid, styrenesulfonic acid, trifluoroacetic acid, barbituric acid, acrylic acid, methacrylic acid, cinnamic acid, 4-hydroxybenzoic acid, aminobenzoic acid, naphthalenedisulfonic acid, hydroxybenzenesulfonic acid, toluenesulfinic acid, benzenesulfinic acid, α-resorcinic acid, β-resorcinic acid, γ-resorcinic acid, gallic acid, phloroglycin, sulfosalicylic acid, ascorbic acid, erythorbic acid, and bisphenolic acid. Among these, hydrochloric acid, acetic acid, sulfuric acid, and formic acid are preferred, with hydrochloric acid being more preferred. The above acidic compounds may be used alone or in combination of two or more.

[0064] From the viewpoint of neutralization, when adjusting the pH of mixture 1 to 6.0-7.0 after adjusting the pH to 10.0 or lower, the temperature is preferably 5-80°C, more preferably 10-50°C, and even more preferably 15-35°C. The treatment time (neutralization time) at pH 6.0-7.0 is usually 3 seconds or more, preferably 10 seconds to 10 hours, more preferably 30 seconds to 5 hours, and even more preferably 1 minute to 3 hours.

[0065] In step 2, it is preferable to adjust the solid content of mixture 2 (100% by mass) to 0.3% by mass or more, more preferably 0.7% by mass or more, and even more preferably 1.0% by mass or more. There is no particular upper limit, but it is preferably 20.0% by mass or less, more preferably 10.0% by mass or less, even more preferably 5.0% by mass or less, and especially preferably 2.0% by mass or less.

[0066] (Step 3) In step 3, the mixture 2 obtained in step 2 is sprayed onto the inorganic powder and dried to produce a carrier body in which microfibrillated plant fibers are attached to the inorganic powder.

[0067] Inorganic powders that can be used in step 3 include inorganic fillers such as silica, carbon black, calcium carbonate, talc, alumina, clay, aluminum hydroxide, aluminum oxide, and mica. Among these, silica is preferred. In this specification, microfibrillated plant fibers are not considered inorganic powders.

[0068] The average particle size of the inorganic powder used in step 3 is preferably 24 nm or less, more preferably 17 nm or less, even more preferably 15 nm or less, and also preferably 6 nm or more, more preferably 9 nm or more, and even more preferably 12 nm or more. A better effect tends to be obtained when the particle size is within the above range.

[0069] In this specification, the method for measuring the average particle size of inorganic powder is transmission electron microscopy (TEM). Specifically, the inorganic powder particles are photographed with a transmission electron microscope, and if the particle shape is spherical, the diameter of the sphere is defined as the particle size; if it is needle-shaped or rod-shaped, the shorter axis is defined as the particle size; if it is irregularly shaped, the average particle size from the center is defined as the particle size; and the average value of the particle sizes of 100 fine particles is defined as the average particle size.

[0070] Examples of silica include dry-process silica (anhydrous silica) and wet-process silica (hydrated silica). These may be used individually or in combination of two or more types. Among these, wet-process silica is preferred because it contains a large number of silanol groups.

[0071] The specific surface area (N2SA) of silica for nitrogen adsorption is preferably 40 m². 2 / g or more, comfortably 50m 2 / g or more, more preferably 60m 2 It is 1 / g or more. Furthermore, the N2SA content of silica is preferably 250m 2 / g or less, more preferably 220m 2 / g or less, more preferably 200m 2 It is less than or equal to / g. Within the above range, the effect tends to be more favorably obtained. Note that the N2SA value of silica is measured by the BET method in accordance with ASTM D3037-93.

[0072] For example, silica products from companies such as Degussa, Rhodia, Tosoh Silica Co., Ltd., Solvay Japan Co., Ltd., and Tokuyama Corporation can be used.

[0073] In step 3, the spraying and drying of mixture 2 onto the inorganic powder can be carried out, for example, using a known fluidized bed dryer. A "fluidized bed dryer" is a device that supplies heated fluidized air to a chamber and circulates the material to be processed inside while drying it. In step 3, a fluidized bed dryer equipped with a spraying mechanism is used. In this case, by fluidizing the inorganic powder inside the fluidized bed dryer and spraying mixture 2, microfibrillated plant fibers are attached to at least a portion of the surface of the inorganic powder, and further drying is performed to obtain a carrier on which microfibrillated plant fibers are attached to at least a portion of the surface of the inorganic powder.

[0074] As a spraying mechanism, for example, ejection devices such as spray nozzles and discharge devices can be used. The ejection devices and discharge devices can be attached to the bottom, sides, or top of the fluidized bed provided in the apparatus and can spray toward the fluidized bed. Spraying can be performed not only toward the center of the fluidized bed, but also by applying various methods. The fluidized bed dryer may also be an apparatus equipped with a stirring, mixing, and rolling mechanism, such as a stirring blade or a rotating disc, to provide stirring and rolling action to the powder.

[0075] From the viewpoint of obtaining better results, a known fluidized bed granulation dryer (fluidized bed granulation apparatus) can be suitably used as the fluidized bed dryer. The fluidized bed granulation dryer can use equipment that is normally used for fluidized bed granulation, and examples include an apparatus that includes a granulation tank for containing, granulating, and drying the material to be processed, a hot air supply device for supplying hot air to fluidize the material to be processed, and a spray nozzle for spraying liquid onto the material to be processed.

[0076] Among fluidized bed granulation dryers, from the viewpoint of obtaining greater effectiveness, a composite fluidized bed granulation dryer equipped with a jet, tumbling, stirring, and pulse generation mechanism is preferred for granulation, a dryer equipped with a tumbling mechanism (tumbling fluidized bed granulation coating device) is more preferred, a dryer equipped with a pulse generation mechanism (pulsed fluidized bed granulation dryer) is more preferred, and a dryer equipped with a tumbling mechanism is even more preferred. In such a composite fluidized bed granulation dryer, the granulated material is subjected to jets, tumbling, stirring, and periodic changes in air velocity by forced circulation from the sides of the fluidized bed, granular crushing, rotation of a blade rotor in the fluidized bed, and a pulse generation mechanism.

[0077] A fluidized bed dryer is preferably one that introduces hot air into the fluidized bed as the drying air. Regarding the processing conditions during drying, the temperature of the hot air (supply air temperature) should be set appropriately considering the components contained in the material to be processed, but preferably it is in the range of 60 to 180°C, more preferably 70 to 150°C, and even more preferably 80 to 120°C. The wind speed of the hot air (supply air volume) is preferably 0.1 to 3.0 m / sec, more preferably 0.2 to 2.5 m / sec, and even more preferably 0.3 to 2.0 m / sec.

[0078] The processing time (drying time) in step 3 can be set appropriately considering the components contained in the material to be processed, but is preferably 1 minute or more, more preferably 5 minutes or more, even more preferably 7 minutes or more, and also preferably 10 hours or less, more preferably 1 hour or less, and even more preferably 30 minutes or less.

[0079] The rate at which mixture 2 is introduced into the fluidized bed dryer can be set appropriately considering the spraying conditions, but is preferably 1.0 g / min or more, more preferably 3.0 g / min or more, even more preferably 5.0 g / min or more, and also preferably 20.0 g / min or less, more preferably 10.0 g / min or less, and even more preferably 8.0 g / min or less.

[0080] In the spraying and drying process of step 3, the amount of microfibrillated plant fibers added per 100 parts by mass of inorganic powder is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, and particularly preferably 50 parts by mass or more, and also preferably 150 parts by mass or less, more preferably 100 parts by mass or less, even more preferably 80 parts by mass or less, and particularly preferably 70 parts by mass or less.

[0081] Commercially available fluidized bed dryers include the Flow Coater (manufactured by Freund Industrial Co.), GPCG-CT series, WST / WSG series, BF series, PLS series (pulsed fluidized bed granulation dryer), and MP series (tumbling fluidized bed granulation coating equipment) (all manufactured by Powrec Co., Ltd.).

[0082] In step 3, the drying process is preferably performed to adjust the solid content of the prepared carrier (100% by mass) to 85% by mass or more, more preferably 90% by mass or more, even more preferably 92% by mass or more, and particularly preferably 94% by mass or more. The upper limit is not particularly limited and may be 100% by mass. The term "solid content" refers to the content of solid components composed of microfibrillated plant fibers, inorganic powders, epoxidized vegetable oils, etc., in 100% by mass of the carrier.

[0083] Step 3 produces a carrier in which microfibrillated plant fibers are attached to an inorganic powder. In this specification, the term "carrier" is not particularly limited as long as it is an inorganic powder to which microfibrillated plant fibers are attached. For example, it could be an inorganic powder to which microfibrillated plant fibers are attached to at least a portion of its surface, or an inorganic powder to which at least a portion of its surface is covered with microfibrillated plant fibers. Alternatively, it could be an inorganic powder to which microfibrillated plant fibers are attached to at least a portion of the surface of the particles, or an inorganic powder aggregate to which microfibrillated plant fibers are attached to at least a portion of its surface.

[0084] Examples of the carriers that can be produced include those in which microfibrillated plant fibers are attached to at least a portion of the surface of an aggregate of inorganic powder.

[0085] The carrier, in which microfibrillated plant fibers are attached to at least a portion of the surface of an aggregate of inorganic powder, preferably has an average particle diameter of 100 μm or less (powder). The average particle diameter is more preferably 50 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. The lower limit is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more. Here, particle size control of the granules (the carrier) produced using a fluidized bed dryer can be carried out by adjusting the amount of material remaining in the fluidized bed, adjusting the position of the spray nozzle, etc.

[0086] As the aggregate of inorganic powder, an aggregate of silica particles is preferred, in which case the support is one in which microfibrillated plant fibers are attached to at least a portion of the surface of the silica particle aggregate.

[0087] Examples of aggregate shapes of inorganic powders include aggregates with granular (granular) or micro-pearl shapes.

[0088] <Carrier> The above manufacturing method yields a carrier in which microfibrillated plant fibers are supported on an inorganic powder. Examples of such carriers include those in which microfibrillated plant fibers are attached to the surface of an aggregate of inorganic powder. The carrier preferably has a solid content of 85% by mass or more, more preferably 90% by mass or more, even more preferably 92% by mass or more, and particularly preferably 94% by mass or more. The "solid content" refers to the content of solid components composed of microfibrillated plant fibers, inorganic powder, epoxidized vegetable oil, etc., in 100% by mass of the carrier.

[0089] The support material is preferably made up of particles (powder) with an average particle diameter of 100 μm or less. The average particle diameter is more preferably 50 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. The lower limit is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more.

[0090] Preferably, the support has a inorganic powder content of 30.0 to 99.0% by mass and a microfibrillated plant fiber content of 1.0 to 70.0% by mass in 100% by mass of the support. The inorganic powder content is more preferably 60.0 to 97.0% by mass, even more preferably 80.0 to 95.0% by mass, and particularly preferably 85.0 to 93.0% by mass. The microfibrillated plant fiber content is more preferably 3.0 to 30.0% by mass, even more preferably 4.0 to 20.0% by mass, and particularly preferably 5.0 to 10.0% by mass.

[0091] Examples of carriers containing microfibrillated plant fibers and inorganic powder include powdered carriers obtained by spraying a mixture containing the aforementioned microfibrillated plant fibers with an average fiber diameter of 10 μm or less and the plasticizer having epoxy groups onto inorganic powder that has been flowed into air, and then drying the mixture. Such carriers can be manufactured, for example, by the manufacturing method described above.

[0092] One example of a carrier in which microfibrillated plant fibers are attached to an inorganic powder is a carrier in which the inorganic powder and the microfibrillated plant fibers dissociate when stress is applied. It is thought that by applying stress to the carrier, the carrier, which consists of an aggregate of inorganic powder and microfibrillated plant fibers attached to the surface of the aggregate, breaks down, the aggregate of inorganic powder and the microfibrillated plant fibers dissociate, and the aggregate of inorganic powder and microfibrillated plant fibers breaks apart. Such a carrier can be manufactured, for example, by the manufacturing method described above.

[0093] In this specification, "a carrier in which the inorganic powder and the microfibrillated plant fibers dissociate when stress is applied" refers to a carrier having the states before and after dissociation described below under the following test conditions. (Test conditions) When a 5-gram load is weighed and passed through a 200-mesh filter before ultrasonic stimulation (before dissociation), the amount of substance that passes through the filter is measured to be 4.5 grams or more. On the other hand, the carrier weighing 0.5 grams was 5 cm 3 When the substance is sealed in a glass container and subjected to 25 kHz ultrasound for 30 minutes (after dissociation), and then passed through the same filter, the amount of substance that passes through the filter is measured to be 0.45 grams or more. Furthermore, more than 50% by mass of the material that passes through is cellulose.

[0094] Furthermore, in this specification, "dissociation" refers to a state in which at least a portion of the adhesion between the inorganic powder and the microfibrillated plant fibers has been released compared to before the application of stress, and preferably a state in which the inorganic powder and microfibrillated plant fibers do not adhere to each other and exist separately.

[0095] From the viewpoint of dissociation, the stress is preferably applied by a Banbury mixer. In this case, the stress may be applied only to the carrier, but it is desirable that the stress is applied to a rubber composition containing rubber components, which will be described later, so that the inorganic powder and the microfibrillated plant fibers dissociate from the carrier.

[0096] The mixing conditions for the Banbury mixer are preferably such that the rotor speed is 20 rpm or higher. More preferably 25 rpm or higher, and even more preferably 40 rpm. There is no particular upper limit, but it is preferably 100 rpm or lower, more preferably 80 rpm or lower, and even more preferably 70 rpm or lower.

[0097] From the viewpoint of the aforementioned dissociation, it is preferable that the stress be applied by a twin-screw extruder. It is also desirable that the carrier is one in which stress is applied to a rubber composition containing rubber components, which will be described later, thereby causing the inorganic powder and microfibrillated plant fibers to dissociate.

[0098] The mixing conditions for the twin-screw extruder are preferably such that the rotor speed is 50 rpm or higher. More preferably 70 rpm or higher, and even more preferably 80 rpm. There is no particular upper limit, but it is preferably 500 rpm or lower, more preferably 300 rpm or lower, and even more preferably 200 rpm or lower.

[0099] From the viewpoint of obtaining greater effectiveness, it is preferable that the carrier (a carrier in which microfibrillated plant fibers are attached to inorganic powder) satisfies the following formula in terms of the average fiber diameter of the microfibrillated plant fibers and the average particle diameter of the inorganic powder. Average particle size of inorganic powder / Average fiber diameter of microfibrillated plant fiber < 0.50 The ratio of the average particle size of the inorganic powder to the average fiber size of the microfibrillated plant fibers is more preferably 0.45 or less, and even more preferably 0.40 or less.

[0100] <Rubber compositions, resin compositions> The aforementioned support can be used as an additive to rubber compositions or resin compositions. By incorporating the support into a composition, it is possible to effectively disperse microfibrillated plant fibers and inorganic powders within the composition, thereby providing a desired reinforcing effect. In particular, it is desirable to incorporate the support into rubber compositions.

[0101] (Rubber composition) In the rubber composition, the content of microfibrillated plant fibers per 100 parts by mass of rubber component is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, and also preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 85 parts by mass or less.

[0102] In the rubber composition, the inorganic powder content is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, per 100 parts by mass of the rubber component. The content is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, and even more preferably 100 parts by mass or less.

[0103] As described above, silica is preferred as the inorganic powder, but in the rubber composition, the silica content is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, per 100 parts by mass of the rubber component. The content is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, and even more preferably 100 parts by mass or less.

[0104] Examples of rubber components in rubber compositions include diene rubbers. Examples of diene rubbers include isoprene rubber, butadiene rubber (BR), styrene-butadiene rubber (SBR), styrene-isoprene-butadiene rubber (SIBR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), and acrylonitrile-butadiene rubber (NBR). Butyl rubbers and fluororubbers are also examples. Among these, isoprene rubber, BR, and SBR are preferred from the viewpoint of tire properties.

[0105] The diene rubber can be either unmodified diene rubber or modified diene rubber. Modified diene rubbers can be any diene rubber having a functional group that interacts with a filler such as silica. Examples include end-modified diene rubbers (end-modified diene rubbers having the functional group at the end) in which at least one end of the diene rubber is modified with a compound (modifier) ​​having the functional group, main-chain modified diene rubbers having the functional group in the main chain, main-chain end-modified diene rubbers having the functional group in both the main chain and the end (for example, main-chain end-modified diene rubbers having the functional group in the main chain and at least one end modified with the modifier), and end-modified diene rubbers that are modified (coupled) with a polyfunctional compound having two or more epoxy groups in the molecule, and in which hydroxyl groups or epoxy groups are introduced.

[0106] Examples of the above functional groups include amino groups, amide groups, silyl groups, alkoxysilyl groups, isocyanate groups, imino groups, imidazole groups, urea groups, ether groups, carbonyl groups, oxycarbonyl groups, mercapto groups, sulfide groups, disulfide groups, sulfonyl groups, sulfinyl groups, thiocarbonyl groups, ammonium groups, imide groups, hydrazo groups, azo groups, diazo groups, carboxyl groups, nitrile groups, pyridyl groups, alkoxy groups, hydroxyl groups, oxy groups, epoxy groups, and the like. These functional groups may have substituents. Among these, amino groups (preferably amino groups in which the hydrogen atoms of the amino group are substituted with C1-C6 alkyl groups), alkoxy groups (preferably alkoxy groups having C1-C6), and alkoxysilyl groups (preferably alkoxysilyl groups having C1-C6) are preferred.

[0107] Examples of isoprene-based rubbers include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, and modified IR. For NR, for example, commonly used rubbers in the tire industry such as SIR20, RSS#3, and TSR20 can be used. For IR, there are no particular limitations, and commonly used rubbers in the tire industry such as IR2200 can be used. Examples of modified NR include deproteinized natural rubber (DPNR) and high-purity natural rubber (UPNR). Examples of modified NR include epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), and grafted natural rubber. Examples of modified IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, and grafted isoprene rubber. These may be used individually or in combination of two or more types.

[0108] In the rubber composition, the content of isoprene-based rubber in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

[0109] The butadiene rubber (BR) is not particularly limited and can be any of the types commonly used in the tire industry, such as high-cis content BR, BR containing 1,2-syndiotactic polybutadiene crystals (SPB-containing BR), butadiene rubber synthesized using rare earth element catalysts (rare earth element BR), or tin-modified butadiene rubber modified with tin compounds (tin-modified BR). Commercially available BR products from companies such as Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, and Nippon Zeon Corporation can be used. These may be used individually or in combination of two or more types. The BR may be unmodified BR or modified BR.

[0110] The cis content of BR is preferably 90% by mass or more, and more preferably 95% by mass or more, from the viewpoint of good ice and snow performance and wear resistance. In this specification, the cis content (cis-1,4-bond amount) is a value calculated from the signal intensity measured by infrared absorption spectroscopy or NMR analysis.

[0111] In the rubber composition, the BR content in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

[0112] The SBR is not particularly limited; for example, emulsion-polymerized styrene-butadiene rubber (E-SBR), solution-polymerized styrene-butadiene rubber (S-SBR), etc., can be used. These may be used individually or in combination of two or more types.

[0113] The styrene content of SBR is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. Furthermore, the styrene content is preferably 75% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less. In this specification, the styrene content of SBR is as follows: 1 It is calculated by 1H-NMR measurement.

[0114] The vinyl content of SBR is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. The vinyl content is preferably 75% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less. The vinyl content (amount of 1,2-bonded butadiene units) can be measured by infrared absorption spectroscopy.

[0115] For example, SBR manufactured and sold by companies such as Sumitomo Chemical Co., Ltd., JSR Corporation, Asahi Kasei Corporation, and Nippon Zeon Co., Ltd. can be used.

[0116] In the rubber composition, the SBR content in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

[0117] The rubber composition may contain carbon black. The carbon black is not particularly limited, and examples include furnace black (furnace carbon black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF, and ECF; acetylene black (acetylene carbon black); thermal black (thermal carbon black) such as FT and MT; channel black (channel carbon black) such as EPC, MPC, and CC; graphite, etc. These may be used alone or in combination of two or more.

[0118] The nitrogen adsorption specific surface area (N2SA) of the carbon black is preferably 30 m 2 / g or more, more preferably 35 m 2 / g or more, still more preferably 40 m 2 / g or more. The upper limit is not particularly limited, but preferably 250 m 2 / g or less, more preferably 200 m 2 / g or less, still more preferably 180 m 2 / g or less. Note that the N2SA of the carbon black is determined according to JIS K 6217-2:2001.

[0119] In the rubber composition, the content of carbon black is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more with respect to 100 parts by mass of the rubber component. The content is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, still more preferably 100 parts by mass or less.

[0120] The tread rubber composition preferably contains a silane coupling agent together with silica. The silane coupling agent is not particularly limited and includes, for example, bis(3-triethoxysilylpropyl)tetrasulfide, bis(2-triethoxysilylethyl)tetrasulfide, bis(4-triethoxysilylbutyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, bis(2-triethoxysilylethyl) trisulfide, bis(4-trimethoxysilylbutyl) trisulfide, bis(3-triethoxysilylpropyl) disulfide, bis(2-triethoxysilylethyl) disulfide, bis(4-triethoxysilylbutyl) disulfide, bis(3-trimethoxysilylpropyl) disulfide, bis(2-trimethoxysilylethyl) disulfide, bis(4-trimethoxysilylbutyl) disulfide, and 3-trimethoxysilylpropyl-N,N-dimethylthiocal Examples include sulfide compounds such as bamoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide and 3-triethoxysilylpropyl methacrylate monosulfide; mercapto compounds such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and Momentive's NXT and NXT-Z; vinyl compounds such as vinyltriethoxysilane and vinyltrimethoxysilane; amino compounds such as 3-aminopropyltriethoxysilane and 3-aminopropyltrimethoxysilane; glycidoxy compounds such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; nitro compounds such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane; and chloro compounds such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. These may be used individually or in combination of two or more. Among these, sulfide-based and mercapto-based compounds are preferred because they provide better efficacy.

[0121] Examples of silane coupling agents that can be used include products from companies such as Degussa, Momentive, Shin-Etsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., and Toray Dow Corning Co., Ltd.

[0122] In the rubber composition, the content of the silane coupling agent is preferably 3 parts by mass or more, and more preferably 5 parts by mass or more, per 100 parts by mass of silica. Furthermore, the above content is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

[0123] The rubber composition may contain other plasticizers in addition to the epoxy group-containing plasticizer used in the manufacturing method described above. Examples of other plasticizers include other liquid plasticizers (plasticizers that are liquid at 25°C) and solid plasticizers (plasticizers that are solid at 25°C). The plasticizers may be used alone or in combination of two or more types.

[0124] The liquid plasticizer is not particularly limited and includes oils, liquid resins, liquid diene polymers, etc. Among these, oils are preferred from the viewpoint of obtaining better effects.

[0125] The oil is not particularly limited and can be any known oil, such as process oil, vegetable oil, or mixture thereof. Examples of process oils include paraffinic process oil, aromatic process oil, naphthenic process oil, and low-PCA (polycyclic aromatic) process oils such as TDAE and MES. Examples of vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil (canola oil), soybean oil, palm oil, coconut oil, peanut oil, rosin, pine oil, pine tar, tall oil, corn oil, rice oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. These can be used individually or in combination of two or more.

[0126] Examples of solid plasticizers include aromatic vinyl polymers that are solid at room temperature (25°C), coumarone indene resin, coumarone resin, indene resin, phenolic resin, rosin resin, petroleum resin, terpene resin, and acrylic resin. The resins may also be hydrogenated. These may be used individually or in combination of two or more.

[0127] In the rubber composition, the total amount of plasticizer (total amount of plasticizer in the carrier and separately blended plasticizer) is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more, per 100 parts by mass of the rubber component. The upper limit is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less.

[0128] The rubber composition preferably contains an anti-aging agent. While not particularly limited, the following are examples of anti-aging agents: naphthylamine-based anti-aging agents such as phenyl-α-naphthylamine; diphenylamine-based anti-aging agents such as octylated diphenylamine and 4,4′-bis(α,α′-dimethylbenzyl)diphenylamine; N-isopropyl-N′-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine, and N,N′-di-2-naphthyl-p-phenylenediamine. Examples of anti-aging agents include p-phenylenediamine-based anti-aging agents such as amines; quinoline-based anti-aging agents such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline; monophenol-based anti-aging agents such as 2,6-di-t-butyl-4-methylphenol and styrenated phenol; and bis, tris, and polyphenol-based anti-aging agents such as tetrakis-[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane. Among these, p-phenylenediamine-based anti-aging agents and quinoline-based anti-aging agents are preferred, and polymers of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine and 2,2,4-trimethyl-1,2-dihydroquinoline are more preferred. Commercial products such as those from Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Co., Ltd., and Flexis Co., Ltd. can be used.

[0129] In the rubber composition, the content of the anti-aging agent is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, per 100 parts by mass of the rubber component. The content is preferably 7.0 parts by mass or less, more preferably 4.0 parts by mass or less.

[0130] The rubber composition may contain stearic acid. In the rubber composition, the stearic acid content is preferably 0.5 to 10 parts by mass or more, more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the rubber component.

[0131] In addition, conventionally known stearic acid can be used, such as products from NOF Corporation, Kao Corporation, Fujifilm Wako Pure Chemical Industries Ltd., Chiba Fatty Acid Co., Ltd., etc.

[0132] The rubber composition may contain zinc oxide. In the rubber composition, the zinc oxide content is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the rubber component.

[0133] In addition, conventionally known zinc oxides can be used, such as products from Mitsui Mining & Smelting Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Seido Chemical Industry Co., Ltd., and Sakai Chemical Industry Co., Ltd.

[0134] The rubber composition may contain wax. In the rubber composition, the wax content is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the rubber component.

[0135] The type of wax used is not particularly limited and includes petroleum-based waxes, natural waxes, and synthetic waxes obtained by refining or chemically processing multiple waxes. These waxes may be used individually or in combination of two or more types.

[0136] Examples of petroleum-based waxes include paraffin wax and microcrystalline wax. Examples of natural waxes are not limited to those derived from non-petroleum resources, and include plant-based waxes such as candelilla wax, carnauba wax, wood wax, rice wax, and jojoba wax; animal-based waxes such as beeswax, lanolin, and whale wax; mineral waxes such as ozokerite, ceresin, and petrolactam; and refined products thereof. Commercially available products include those from companies such as Ouchi Shinko Chemical Industry Co., Ltd., Nippon Seiro Co., Ltd., and Seiko Chemical Co., Ltd.

[0137] Sulfur may be added to the rubber composition. In the rubber composition for treads, the sulfur content is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 0.7 parts by mass or more, per 100 parts by mass of the rubber component. The content is preferably 6.0 parts by mass or less, more preferably 4.0 parts by mass or less, and even more preferably 3.0 parts by mass or less.

[0138] Examples of sulfur commonly used in the rubber industry include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur. Commercially available products include those from Tsurumi Chemical Industries, Karuizawa Sulfur Co., Ltd., Shikoku Chemicals Co., Ltd., Flexis Co., Ltd., Nippon Dry Distillation Co., Ltd., and Hosoi Chemical Industry Co., Ltd. These can be used individually or in combination of two or more types.

[0139] The rubber composition may contain a vulcanization accelerator. In a rubber composition for treads, the content of the vulcanization accelerator is usually 0.3 to 10 parts by mass, preferably 0.5 to 7 parts by mass, per 100 parts by mass of the rubber component.

[0140] There are no particular restrictions on the type of vulcanization accelerator; commonly used ones can be used. Examples of vulcanization accelerators include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiadylsulfenamide; thiuram-based vulcanization accelerators such as tetramethylthiuram disulfide (TMTD), tetrabenzylthiuram disulfide (TBzTD), and tetrakis(2-ethylhexyl)thiuram disulfide (TOT-N); sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazolesulfenamide, Nt-butyl-2-benzothiazolylsulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, and N,N'-diisopropyl-2-benzothiazolesulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, diortotrilguanidine, and orthotrilbiguanidine. These may be used individually or in combination of two or more. Among them, sulfenamide-based vulcanization accelerators and guanidine-based vulcanization accelerators are preferred.

[0141] In the rubber composition, the content of the vulcanization accelerator is preferably 0.3 to 4.0 parts by mass, preferably 0.5 to 2.5 parts by mass, and more preferably 0.7 to 1.6 parts by mass, per 100 parts by mass of the rubber component.

[0142] As a method for producing the rubber composition, known methods can be used, for example, a method that includes a step of mixing the carrier and the rubber component. Specifically, for example, the rubber composition can be produced by kneading each component, such as the carrier and the rubber component, using a rubber kneading device such as an open roll or Banbury mixer, and then vulcanizing it.

[0143] Regarding the mixing conditions, in the base mixing step where additives other than the vulcanizing agent and vulcanization accelerator are mixed, the mixing temperature is usually 50 to 200°C, preferably 80 to 190°C, and the mixing time is usually 30 seconds to 30 minutes, preferably 1 minute to 30 minutes. In the finish mixing step where the vulcanizing agent and vulcanization accelerator are mixed, the mixing temperature is usually 100°C or lower, preferably room temperature to 80°C. Furthermore, the composition mixed with the vulcanizing agent and vulcanization accelerator is usually subjected to a vulcanization treatment such as press vulcanization. The vulcanization temperature is usually 120 to 200°C, preferably 140 to 180°C.

[0144] The rubber composition can be suitably applied as a component for tires. The tire components are not particularly limited and include any tire components such as the cap tread, sidewall, base tread, bead apex, clinch apex, inner liner, undertread, breaker topping, and pry topping.

[0145] The tire component is preferably obtained by extruding a rubber composition obtained by the manufacturing method described above, and the microfibrillated plant fibers are oriented in the extrusion direction. In this case, the tire component can be given an excellent reinforcing effect.

[0146] Tires include pneumatic tires and non-pneumatic tires. Among these, pneumatic tires are preferred. For example, they can be suitably used as summer tires and winter tires (studless tires, snow tires, studless tires, etc.). These tires can be used for passenger cars, large passenger cars, large SUVs, heavy-duty trucks and buses, light trucks, motorcycles, and racing tires (high-performance tires).

[0147] The tire is manufactured by conventional methods using a rubber composition containing the above-mentioned carrier and the like. Specifically, a rubber composition, with various additives added as needed, can be extruded to match the shape of the tire components at the unvulcanized stage, molded in conventional methods on a tire molding machine, bonded together with other tire components to form an unvulcanized tire, and then heated and pressurized in a vulcanizing machine to manufacture the tire.

[0148] (Resin composition) When the support is used as an additive to a resin composition, the resin composition may include, for example, a dispersion resin and the support.

[0149] The dispersion resin is not particularly limited and includes known resins. Examples include petroleum-based resins, coal-based resins, terpene-based resins, and rosin-based resins, but it is preferable that it be at least one selected from the group consisting of petroleum-based resins and coal-based resins, with petroleum-based resins being more preferable.

[0150] Examples of petroleum-based resins include C5 petroleum resins, C9 petroleum resins, C5C9 petroleum resins, dicyclopentadiene resins, and their hydrides, as well as modified products obtained by grafting cyclic polybasic anhydrides (e.g., maleic anhydride) to these. Among these, C9 petroleum resins are preferred.

[0151] Examples of the coal-based resins include coumarone resin, coumarone indene resin, and their hydrides, as well as modified products obtained by grafting cyclic polybasic anhydrides (e.g., maleic anhydride) to these resins.

[0152] Examples of the terpene resins include α-pinene resin, β-pinene resin, terpene phenol resin, aromatically modified terpene resin, and their hydrides, as well as modified products obtained by adding maleic anhydride to these.

[0153] Examples of the rosin-based resins include gum rosin, wood rosin, tall rosin, hydrogenated rosin, disproportionated rosin, maleic acid-modified rosin, fumaric acid-modified rosin, (meth)acrylic acid-modified rosin, esterified rosin condensed with alcohol, and phenol-modified rosin.

[0154] The aforementioned dispersion resin is preferably 135°C or lower in a ring-ball test in accordance with JIS K2207. The softening point is preferably 120°C or lower, and more preferably 110°C or lower. On the other hand, the softening point is preferably 40°C or higher, more preferably 60°C or higher, and even more preferably 80°C or higher.

[0155] In the resin composition, the content of microfibrillated plant fibers per 100 parts by mass of dispersion resin is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, and also preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 85 parts by mass or less.

[0156] In the resin composition, the inorganic powder content is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, per 100 parts by mass of the dispersion resin. The content is preferably 150 parts by mass or less, more preferably 120 parts by mass or less, and even more preferably 100 parts by mass or less.

[0157] The resin composition can be manufactured by known methods, for example, by known kneading methods. Suitable kneaders include two-roll mills, three-roll mills, single-screw extruders, twin-screw extruders, Banbury mixers, and pressure kneaders.

[0158] Resin compositions can be molded into various shapes for use. Examples of shapes include sheets, films, pellets, and powders. Molded materials having these shapes can be obtained using methods such as press molding, injection molding, extrusion molding, blow molding, stretch molding, foam molding, transfer molding, lamination molding, and casting.

[0159] The molding material may contain, as needed, lubricants, waxes, colorants, stabilizers, fillers, and various other additives.

[0160] Molded bodies produced from the molding material can be used, for example, as interior, exterior, and structural materials for transportation equipment such as automobiles, trains, ships, and airplanes; as casings, structural materials, and internal components for electrical appliances such as personal computers, televisions, telephones, and watches; as casings, structural materials, and internal components for mobile communication equipment such as mobile phones; as casings, structural materials, and internal components for portable music players, video players, printing machines, photocopiers, and sporting goods; as building materials; and for office equipment such as stationery, containers, and other items. [Examples]

[0161] The present invention will be specifically described based on the examples provided, but the present invention is not limited to these examples.

[0162] Microfibrillated plant fiber 1: BiNFi-s manufactured by Sugino Machine Co., Ltd. (cellulose microfibers processed with ultra-high pressure water jet technology, average fiber diameter: 35 nm, average fiber length: 650 nm) Microfibrillated plant fiber 2: BiNFi-s T series manufactured by Sugino Machine Co., Ltd. (carboxymethylated cellulose nanofiber, average fiber diameter: 35 nm, average fiber length: 650 nm) Epoxidized soybean oil: Manufactured by ADEKA Corporation (Oxylan oxygen content 7.0% by mass) Epoxidized linseed oil: Manufactured by Shin-Nippon Rika Co., Ltd. (Oxylan oxygen content 8.5% by mass) Silica 1: UltraSil VN3 manufactured by Evonik DeGussa (average particle size 17 nm) Silica 2: Evonik De Gussa's UltraSil 9100GR (average particle size 15nm) SBR: Nipol 1502 (E-SBR, styrene content 23.5% by mass) manufactured by Nippon Zeon Co., Ltd. Carbon black: Diablack N220 (N2SA111m) manufactured by Mitsubishi Chemical Corporation. 2 / g) Anti-aging agent: Nocrack 6C (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Zinc oxide: Zinc oxide No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: Stearic acid "Tsubaki" manufactured by NOF Corporation Sulfur: HK-200-5 (5% by mass oil-containing powdered sulfur) manufactured by Hosoi Chemical Industry Co., Ltd. Vulcanization accelerator: Noxellar CZ (N-cyclohexyl-2-benzothiazolyl sulfenamide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0163] <Preparation of mixtures 1-1 to 1-3> 50 g of microfibrillated plant fiber was added to 2950 g of pure water to prepare a 0.5% by mass (solid content concentration) suspension of microfibrillated plant fiber, and a homogeneous aqueous dispersion was prepared by stirring for approximately 5 minutes in a high-speed homogenizer (IKA Japan's "T50", rotation speed: 10000 rpm). According to the formulation shown in Table 1, epoxidized vegetable oil was added to the aqueous dispersion prepared above (calculated on the dry mass (solids) of microfibrillated plant fibers) to prepare mixtures 1-1 to 1-3 (solids content: approximately 0.6% by mass, moisture content: approximately 99.4% by mass).

[0164] [Table 1]

[0165] <Preparation of mixtures 2-1 to 2-3> Mixtures 1-1 to 1-3 were prepared, and a 1N sodium hydroxide aqueous solution was added to bring the pH down to 12.0. The mixture was then stirred overnight at room temperature and a rotation speed of 300 rpm. Next, a 1N hydrochloric acid aqueous solution was added to adjust the pH to 6.0-7.0, and mixtures 2-1 to 2-3 (solid content: approximately 1.2% by mass, moisture content: approximately 98.8% by mass) were prepared.

[0166] <Spraying / drying process> Silica and the resulting mixtures 2-1 to 2-3 were introduced into the fluidized bed dryer according to the formulations described in Table 2. Under the conditions described below, the mixtures 2-1 to 2-3 were sprayed onto the silica, granulated, and dried to obtain carriers 1 to 7. Table 3 shows the solid content, average particle size, silica content and microfibrillated plant fiber content per 100% by mass of the carrier, average particle size of silica, average fiber size of microfibrillated plant fibers, and the ratio of average particle size of silica to average fiber size of microfibrillated plant fibers for the prepared carriers 1 to 7 (carriers in which microfibrillated plant fibers are attached to at least a portion of the surface of the silica particle aggregates). (Equipment used) Rolling-type fluid granulation coating machine (manufactured by Powrec Co., Ltd., MP-01 model) (conditions) Silica content: 100g Air intake temperature: 80℃ Air supply air volume: 0.3m 3 / min Drying time: 120 minutes Mixture input rate: 5.0 g / min Spray nozzle diameter: 1.2mm Nozzle tip: 0.0mm protrusion Bag filter removal pressure: 0.15 MPa

[0167] [Table 2]

[0168] [Table 3]

[0169] Using a rolling fluid granulation coating apparatus, a mixture containing microfibrillated plant fibers and a plasticizer having epoxy groups was sprayed onto silica, granulated, and dried to obtain a support (powdered support) in which microfibrillated plant fibers were supported (adhered) to the silica surface. Therefore, it was possible to produce a support in which microfibrillated plant fibers were attached to an inorganic powder using a simple manufacturing method.

[0170] Furthermore, such a support material consisted of an inorganic powder to which microfibrillated plant fibers were attached, and the inorganic powder and the microfibrillated plant fibers would dissociate when stress was applied.

[0171] <Preparation of rubber composition> According to the formulation shown in Table 4, the materials other than sulfur and vulcanization accelerator were kneaded at 150°C for 4 minutes using a 1.7L Banbury mixer. Next, using an open roll, sulfur and vulcanization accelerator were added to the resulting mixture and kneaded at 80°C for 4 minutes to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was press-vulcanized at 170°C for 12 minutes using a 2mm thick mold to obtain a vulcanized rubber composition.

[0172] The obtained vulcanized rubber compositions were evaluated by the following method. Note that Comparative Example 1 was used as the reference comparative example in Table 4. [Evaluation Method] (Dispersibility of microfibrillated plant fibers) The vulcanized rubber compositions were observed using an electron microscope to evaluate the dispersibility of microfibrillated plant fibers in the rubber matrix. The dispersibility of microfibrillated plant fibers in the reference comparative example was set to 100, and each rubber compound was expressed as an index. A higher index indicates better dispersibility of microfibrillated plant fibers.

[0173] (Breaking strength) No. 3 dumbbell-shaped rubber test specimens were prepared using vulcanized rubber compositions, and tensile tests were performed in accordance with JIS K6251 "Vulcanized rubber and thermoplastic rubber - Method for determining tensile properties" to measure the breaking strength (TB). The TB index of the rubber test specimen of the reference comparative example (reference test specimen) was set to 100, and the TB of each formulation was expressed as an index using the following calculation formula. A higher TB index indicates greater breaking strength and superior reinforcing properties. (TB index) = (TB of each formulation) / (TB of the reference comparison) × 100

[0174] [Table 4]

[0175] Table 4 shows that Examples 1-7, using carriers 1-7, exhibited good dispersibility of microfibrillated plant fibers and silica, enabling the provision of excellent reinforcing properties.

Claims

1. Step 1 involves mixing microfibrillated plant fibers, a plasticizer having epoxy groups, and water to produce a mixture 1, Step 2 involves adjusting the pH of the aforementioned mixture 1 to 10.0 or higher, and then adjusting the pH to 6.0 to 7.0 to produce mixture 2. A method for producing a support, comprising step 3 of spraying the mixture 2 onto an inorganic powder and drying it to produce a support in which microfibrillated plant fibers are attached to the inorganic powder.

2. The method for producing a carrier according to claim 1, wherein step 1 uses an aqueous solution of microfibrillated plant fibers having a microfibrillated plant fiber content of 0.1 to 20% by mass, and is mixed using a homogenizer.

3. The method for producing a support according to claim 1 or 2, wherein the plasticizer comprises an epoxidized vegetable oil.

4. The method for producing a support according to any one of claims 1 to 3, wherein the inorganic powder contains silica particles.

5. The method for producing a carrier according to claim 4, wherein the silica particles include aggregates of silica particles.

6. The method for producing a carrier according to claim 5, wherein the aggregate of silica particles has a granular shape and / or a micropearl shape.

7. The method for producing a carrier according to any one of claims 1 to 6, wherein step 1 is the addition of 50 to 200 parts by mass of the epoxy group-containing plasticizer to 100 parts by mass (solid content) of the microfibrillated plant fiber.

8. The method for producing a carrier according to any one of claims 1 to 7, wherein the amount of microfibrillated plant fiber added to 100 parts by mass of the inorganic powder is 30 to 100 parts by mass.

9. The method for producing a support according to any one of claims 1 to 8, wherein step 3 is performed by spraying the mixture 2 onto the inorganic powder that has been fluidized in a fluidized bed dryer and drying it.

10. A carrier in which microfibrillated plant fibers are attached to an inorganic powder, The inorganic powder is silica, The aforementioned support is characterized by containing a plasticizer having epoxy groups.

11. The carrier according to claim 10, which is a powder with an average particle size of 100 μm or less.

12. The carrier according to claim 10 or 11, wherein the average fiber diameter of the microfibrillated plant fibers and the average particle diameter of the inorganic powder satisfy the following formula. Average particle size of inorganic powder / Average fiber size of microfibrillated plant fiber < 0.50

13. A carrier according to any one of claims 10 to 12, which is an additive to a rubber composition or a resin composition.

14. A rubber composition for tires obtained by mixing a carrier according to any one of claims 10 to 13 with a rubber component.

15. A tire comprising a member made of the rubber composition described in claim 14.

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