Anti-slip agent and method for producing Anti-slip agent

Abstract

To provide a novel anti-slip agent having water-absorbing capability within a short period.SOLUTION: An anti-slip agent of the present invention comprises a base powder and cellulose fibers, wherein the content of the cellulose fibers is 50 mass% or less.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an anti-slip agent and a method for producing the anti-slip agent. [Background technology]

[0002] Magnesium carbonate powder, calcium carbonate powder made from crushed eggshells, oyster shells, etc., have traditionally been used as anti-slip agents in sports such as sport climbing (bouldering), track and field, gymnastics, baseball, softball, and golf (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-261213 A Summary of the Invention [Problem to be solved by the invention]

[0004] It would be desirable to impart to these anti-slip agents the ability to absorb water in a short period of time, since this would enable the agents to quickly absorb sweat from the hands and the like.

[0005] Therefore, an object of the present invention is to provide a novel anti-slip agent having the function of absorbing water in a short time, and a method for producing the same. [Means for solving the problem]

[0006] In order to achieve the above object, the anti-slip agent of the present invention comprises: The present invention includes a base powder and cellulose fibers, The blending amount of the cellulose fibers is 50% by mass or less.

[0007] The manufacturing method of the present invention is a method for producing an anti-slip agent which includes a step of mixing a base powder with cellulose fibers, the blending amount of the cellulose fibers being 50 mass % or less. Effect of the Invention

[0008] In view of the above problems, the present inventors conducted a series of studies and discovered that by incorporating 50% by mass or less of cellulose fibers into the anti-slip agent, it becomes possible for the agent to absorb water in a short period of time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The anti-slip agent of the present invention includes a base powder and cellulose fibers. The anti-slip agent may be composed of only the base powder and the cellulose fibers, or may further include other components (e.g., rosin, etc.).

[0010] The base powder may be, for example, magnesium carbonate powder, calcium carbonate powder, a mixture thereof, etc., but is not particularly limited thereto. The base powder may be, for example, a commercially available product. The magnesium carbonate powder is commercially available from many companies, such as Naikai Salt Co., Ltd., Nishi Sports Co., Ltd., and Black Diamond Co., Ltd.

[0011] The amount of the base powder in the total amount of the anti-slip agent may be, for example, the remainder of the other components.

[0012] Examples of the cellulose fibers include pulp and fine cellulose fibers (cellulose nanofibers (CNF)) obtained by defibrating pulp. The pulp is a fibrous material formed by an assembly of multiple cellulose fibers. The cellulose fibers are an assembly of multiple fine fibers (e.g., microfibrils, etc.). The fine fibers are an assembly of multiple cellulose molecules (hereinafter sometimes simply referred to as "cellulose"), which are chain-like polymers in which D-glucose is bonded via β(1→4) glucoside bonds.

[0013] Examples of the pulp include, but are not limited to, wood-based pulp (hereinafter simply referred to as "wood pulp"), dissolving pulp, cotton-based pulp such as cotton linter, non-wood-based pulp such as wheat straw, bagasse, paper mulberry, mitsumata, hemp, kenaf, and fruit, and waste paper pulp prepared from recycled newspapers, magazines, cardboard, etc. From the viewpoint of ease of availability, wood pulp is easily used as the cellulose fiber.

[0014] There are various kinds of wood pulp, but they are not particularly limited, and examples thereof include paper-making pulp such as softwood bleached kraft pulp (NBKP), hardwood bleached kraft pulp (LBKP), thermomechanical pulp (TMP), etc. When the pulp is used as the cellulose fiber, one type of pulp may be used alone, or two or more types of pulp may be used in combination.

[0015] The cellulose fibers (e.g., pulp, CNF, etc.) may be unmodified or chemically modified. Examples of the chemical modification include sulfate esterification of at least a portion of the hydroxyl groups of cellulose, oxidation (e.g., introduction of carboxyl groups using an oxidation reaction with a TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) catalyst), phosphate esterification, phosphite esterification, carboxymethylation, etc. The cellulose fibers may be modified by one type of chemical modification, or by two or more types of chemical modifications.

[0016] In the anti-slip agent, if the cellulose fibers (e.g., pulp, CNF, etc.) have been subjected to sulfate esterification (at least a portion of the hydroxyl groups of cellulose are replaced with sulfate ester groups), it has been confirmed in the examples described below that the anti-slip agent can absorb water in a shorter time.

[0017] Pulp in which at least a portion of the hydroxyl groups of cellulose have been substituted with sulfate ester groups (hereinafter referred to as "sulfated pulp") is a fibrous component formed by an assembly of multiple cellulose fibers, in which at least a portion of the hydroxyl groups (-OH groups) of the cellulose (a chain-like polymer in which D-glucose is bonded via β(1→4) glycosidic bonds) constituting the cellulose fibers contained therein have been substituted with sulfate ester groups as shown in formula (1).

[0018] (-OSO 3 - ) r Z r+ (1) In formula (1), r is an independent natural number from 1 to 7, Z r+ When r=1, it is at least one selected from the group consisting of a hydrogen ion, an alkali metal ion, a monovalent transition metal ion, an ammonium ion, an aliphatic ammonium ion, an aromatic ammonium ion, and a cationic polymer, and when r=2 or more, it is at least one selected from the group consisting of an alkaline earth metal ion, a polyvalent metal ion, and a compound containing two or more cationic functional groups (e.g., diamine, etc.) in the molecule.

[0019] The physical properties of the sulfated pulp are not particularly limited, but are, for example, as follows.

[0020] <Amount of sulfate ester group introduced> The amount of sulfate ester groups introduced per 1 g (solid mass) of sulfated pulp is preferably adjusted to, for example, 0.6 mmol / g or more, 0.8 mmol / g or more, 1 mmol / g or more, or 1.2 mmol / g or more.

[0021] Although there is no particular upper limit, from the viewpoint of suppressing fiber collapse and cost increase caused by decreased crystallinity, for example, the amount of sulfate ester groups introduced per 1 g (solid mass) of sulfated pulp is 9.9 mmol / g or less, or 5 mmol / g or less.

[0022] <Method for measuring the amount of sulfate ester groups introduced> The amount of sulfate ester groups introduced into the sulfated pulp can be evaluated by the amount of sulfur introduced due to the sulfate ester groups, or by directly measuring the sulfate ester groups. For example, the amount of sulfate ester groups introduced into the pulp can be measured using a CHNS / O elemental analyzer. The amount of sulfate ester groups introduced into the pulp can also be calculated by measuring electrical conductivity.

[0023] <Crystallization degree> The sulfated pulp may have, for example, a cellulose I type crystal structure as a crystal structure, and the degree of crystallinity may be 75% or less. From the viewpoint of maintaining the fiber shape, the degree of crystallinity of the sulfated pulp is preferably 30% or more. Furthermore, from the viewpoint of handling in the preparation of the sulfated pulp, the degree of crystallinity of the sulfated pulp is, for example, 30% or more, 40% or more.

[0024] <Method for measuring crystallinity> The crystallinity of the sulfated pulp can be measured, for example, by using an X-ray diffraction apparatus.

[0025] <Average fiber length> The average fiber length of the sulfated pulp is not particularly limited, and is, for example, 0.2 mm to 2 mm, 0.2 mm to 1.8 mm, 0.2 mm to 1.5 mm, or 0.2 mm to 1 mm.

[0026] <Short fiber rate (%)> The sulfated pulp may also contain pulp with short fiber length as described below. Examples of this pulp with short fiber length (hereinafter referred to as "short fiber") include pulp with a fiber length of 0.04 mm or more and 0.2 mm or less in the fiber length distribution. The content (%) of short fibers in the sulfated pulp (i.e., short fiber rate (%)) is, for example, 10% or more, 15% or more.

[0027] From the viewpoint of handleability, the sulfated pulp has a short fiber content (%) (i.e., short fiber rate (%)) of, for example, 10% to 70%, 10% to 60%, 10% to 50%, 10% to 45%, or 15% to 45% in terms of fiber length distribution.

[0028] <Average fiber width> The average fiber width of the sulfated pulp is not particularly limited, and is, for example, 5 μm to 100 μm, 10 μm to 50 μm, 20 μm to 40 μm, or 20 μm to 30 μm.

[0029] <Measuring methods for average fiber length, average fiber width and fiber distribution> The average fiber length and average fiber width of sulfated pulp can be measured, for example, using a fiber tester or fiber length distribution measuring instrument manufactured by Lorentzen & Wettley in accordance with ISO 16065-2: 2007. The fiber length distribution and fiber width distribution of sulfated pulp can be measured, for example, using a fiber length distribution measuring instrument in accordance with ISO 16065-2: 2007.

[0030] <Viscosity> When the degree of crystallinity of sulfated pulp is equal to or less than the aforementioned value, for example, the dispersion has a predetermined viscosity. For example, when the degree of crystallinity of sulfated pulp is 70% or less, the viscosity of a dispersion (solid content concentration 1% by mass) of sulfated pulp dispersed in water is 1000 mPa·s or more, 5000 mPa·s or more, or 10000 mPa·s or more. In particular, when the degree of crystallinity of sulfated pulp is 60% or less, the viscosity of the dispersion tends to increase. Furthermore, this tendency becomes stronger when the average fiber length is 1 mm or less.

[0031] <Method of measuring viscosity> The viscosity (mPa s) of sulfated pulp can be measured, for example, using a B-type viscometer at a measurement temperature of 20°C, with measurements performed at rotation speeds of 6 rpm and 60 rpm, and the thixotropy index (TI) value can also be calculated from each viscosity value. TI value = (viscosity at 6 rpm) / (viscosity at 60 rpm)

[0032] The TI value can be adjusted as appropriate, and when a high TI value is required, the lower limit of the TI value is, for example, 3 or more, 4 or more, or 5 or more. The upper limit of the TI value is, for example, 10 or less, 8 or less, 6 or less, or 5 or less. On the other hand, when a low TI value is preferred, the lower limit is, for example, 1 or more, and the upper limit is, for example, 3 or less, or 2.5 or less.

[0033] Next, the fine cellulose fibers (cellulose nanofibers (CNF), hereinafter referred to as sulfated CNF) obtained by defibrating sulfated pulp will be described.

[0034] The physical properties of the sulfated CNF are not particularly limited, but are, for example, as follows. The amount of sulfate ester groups introduced in the sulfated CNF can be expressed as the amount of sulfur introduced based on the sulfate ester groups. The amount of sulfur introduced per 1 g (mass) of sulfated CNF is, for example, higher than 0.4 mmol / g, and is 0.42 mmol / g to 9.9 mmol / g, 0.5 mmol / g to 9.9 mmol / g, or 0.6 mmol / g to 9.9 mmol / g. If the amount of sulfur introduced is 9.9 mmol / g or less, it is possible to suppress a decrease in crystallinity and an increase in cost when introducing sulfur.

[0035] The amount of sulfur introduced into the sulfated CNF (i.e., the amount of sulfate ester groups introduced) can be measured, for example, using a CHNS / O elemental analyzer. The amount of sulfur introduced can also be calculated, for example, by measuring electrical conductivity.

[0036] The average fiber length of the sulfated CNF can be indirectly expressed, for example, by the degree of polymerization. The average fiber length of the sulfated CNF is, for example, 280 or more, 300 to 1000, or 300 to 600 in terms of the degree of polymerization.

[0037] If the degree of polymerization of the sulfated CNF is 280 or more, it is possible to prevent the fiber length from decreasing and the fiber entanglement from weakening.

[0038] The method for measuring the degree of polymerization is not particularly limited, but for example, the copper ethylenediamine method can be used. The degree of polymerization of the sulfated CNF can be measured by dissolving the sulfated CNF in a 0.5 M copper ethylenediamine solution and measuring the viscosity of the solution by a viscometer.

[0039] The average fiber width of the sulfated CNF is not particularly limited, but is, for example, 1 nm to 1000 nm, 2 nm to 500 nm, 2 nm to 100 nm, 2 nm to 30 nm, or 2 nm to 20 nm when observed with an electron microscope.

[0040] The average fiber width of sulfated CNF can be measured using a known technique. For example, sulfated CNF is dispersed in a dispersion medium such as pure water to prepare a dispersion liquid with a predetermined mass %. Then, this dispersion liquid is spin-coated on a silica substrate coated with PEI (polyethyleneimine), and the sulfated CNF on the silica substrate is observed. For example, a scanning probe microscope (for example, SPM9700 manufactured by Shimadzu Corporation) can be used as an observation method. The average fiber width of sulfated CNF can be obtained by randomly selecting 20 sulfated CNF in the obtained observation image, measuring the fiber width of each fiber, and averaging them.

[0041] Of the cellulose fibers exemplified above, the physical properties of those other than the sulfated pulp and sulfated CNF are not particularly limited.

[0042] For example, in pulp into which carboxyl groups have been introduced by oxidation reaction (hereinafter referred to as "carboxylated pulp"), the carboxyl group content of cellulose is, for example, 0.8 mmol / g to 7 mmol / g, 0.8 mmol / g to 5 mmol / g, 0.8 mmol / g to 2.5 mmol / g, or 0.8 mmol / g to 2 mmol / g. In the present invention, the carboxyl groups are not limited to the acid type (-COOH) but may be in the salt type, i.e., the carboxylate salt group (-COO - X + ) in the carboxylate group. +) is not particularly limited, and examples thereof include hydrogen ions, metal ions, onium ions, cationic organic compounds, and the like.

[0043] <Method for measuring carboxyl group content> The carboxyl group content can be calculated, for example, by preparing 60 mL of a 0.5% to 1% by mass aqueous dispersion from the carboxylated pulp whose dry mass has been precisely weighed, adjusting the pH to about 2.5 with 0.1 M hydrochloric acid, dropping a 0.05 M aqueous sodium hydroxide solution, measuring the electrical conductivity, and continuing until the pH reaches about 11. The carboxyl group content can be calculated using the following formula from the volume (V) of the aqueous sodium hydroxide solution consumed in the neutralization stage of the weak acid, where the change in electrical conductivity is gradual. Carboxyl group content (mmol / g) = V (mL) × (0.05 / dry mass of carboxyl pulp (g))

[0044] The carboxyl group content can also be measured, for example, as follows. That is, the carboxylated pulp is dispersed in water to a solid content concentration of 0.3% by mass to prepare a dispersion, and the dispersion is treated with a household mixer (e.g., Panasonic Corporation, model number: MX-X701, tumbler type) at a strong setting for 1 minute. Next, 70 g of the carboxylated pulp after the treatment is weighed out, 70 g of pure water is added, and the pH is adjusted to about 2.5 by hydrochloric acid treatment, and then the mixture is stirred for 1 hour to obtain a measurement sample. Next, 1.0 M sodium hydroxide aqueous solution is dropped into the measurement sample, and electrical conductivity is measured, and this is continued until the pH becomes about 11. The carboxyl group content is calculated using the following formula from the volume (V) of the sodium hydroxide aqueous solution consumed in the neutralization stage of weak acid, where the change in electrical conductivity is gradual. Carboxyl group content (mmol / g) = V (mL) × (concentration of sodium hydroxide solution (M) / dry mass of carboxyl pulp in the measurement sample (g))

[0045] The average fiber length and its measurement method, short fiber ratio, average fiber width and its measurement method, fiber distribution measurement method, viscosity and its measurement method, and TI value of the carboxylated pulp are not particularly limited, and may be the same as those of the sulfate esterified pulp described above.

[0046] Furthermore, for example, in pulp in which at least a portion of the hydroxyl groups of cellulose are substituted with phosphate groups (hereinafter referred to as "phosphated pulp"), the amount of phosphate groups introduced per gram (mass of solid content) of the phosphated pulp is, for example, 0.8 mmol / g to 7 mmol / g, 0.8 mmol / g to 5 mmol / g, 0.8 mmol / g to 2.5 mmol / g, or 0.8 mmol / g to 2 mmol / g. In the present invention, the phosphate groups are orthophosphate groups (-OPO 3 2- ), but also pyrophosphate ester groups (-OP 2 O 6 3- ), tripolyphosphate ester group (-OPO 3 O 9 4- The counter ion of the phosphate ester group is not particularly limited, and examples thereof include a hydrogen ion, a metal ion, an onium ion, and a cationic organic compound.

[0047] <Method for measuring the amount of introduced phosphate ester groups> The amount of phosphate groups introduced into the phosphated pulp can be measured, for example, by using a conductometric titration method in which a dispersion of the phosphated pulp dispersed in a dispersion medium is treated with an ion exchange resin, and then an aqueous sodium hydroxide solution is added to determine the change in electrical conductivity.

[0048] The dispersion medium constituting the dispersion liquid of the phosphoric esterified pulp is not particularly limited, but examples thereof include protic polar dispersion mediums such as water, ethanol, acetic acid, formic acid, 2-propanol, nitromethane, and ammonia water, aprotic polar dispersion mediums such as acetone, ethyl acetate, tetrahydrofuran (THF), dimethylformamide (DMF), acetonitrile, dimethyl sulfoxide (DMSO), dimethyl sulfide (DMS), and dimethylacetamide (DMA), and non-polar dispersion mediums such as dimethyl ether, benzene, toluene, hexane, chloroform, and 1,4-dioxane, and one of these may be used alone, or two or more may be used in combination. From the viewpoint of handling, protic polar dispersion mediums such as water, ethanol, methanol, acetic acid, formic acid, and ammonia water may be used.

[0049] In addition, the amount of phosphate ester groups introduced into the phosphated pulp can also be quantified as the phosphorus (P) content of the phosphated pulp by elemental analysis using X-ray fluorescence analysis, a method using an inductively coupled plasma optical emission spectrometry (ICP-OES) device, or the like, in addition to the aforementioned conductometric titration method.

[0050] The average fiber length and average fiber width of the phosphate esterified pulp and the method for measuring them are not particularly limited, and may be the same as those of the sulfate esterified pulp described above.

[0051] The fine cellulose fibers (cellulose nanofibers (CNF), hereinafter referred to as carboxylated CNF and phosphated CNF) obtained by defibrating the carboxylated pulp and the phosphated pulp have an average fiber width of, for example, about 1 nm to 100 nm.

[0052] The cellulose fibers may be commercially available or may be prepared in-house. When sulfated pulp, carboxylated pulp, phosphoric esterified pulp, sulfated CNF, carboxylated CNF, and phosphoric esterified CNF are prepared in-house, the following methods may be used, but are not limited to these methods. In addition, when preparing in-house anything other than sulfated pulp, carboxylated pulp, phosphoric esterified pulp, sulfated CNF, carboxylated CNF, and phosphoric esterified CNF among the cellulose fibers exemplified above, the method is not particularly limited, and a conventionally known method may be used.

[0053] The method for preparing this sulfated pulp involves subjecting pulp (e.g., wood pulp, etc.) to a chemical treatment. This chemical treatment step includes a contact step in which the pulp is contacted with a sulfate ester group-donating compound described below and at least one of urea and a urea derivative (hereinafter referred to as "urea, etc." Examples of the urea derivative include thiourea, biuret, phenylurea, benzylurea, dimethylurea, diethylurea, tetramethylurea, benzoleinurea, and hydantoin, and one type may be used alone or two or more types may be used in combination), and a reaction step in which the pulp after this contact step is subjected to a heating reaction to substitute at least a portion of the hydroxyl groups of cellulose with sulfate ester groups.

[0054] The sulfate ester group donating compound is not particularly limited as long as it is a compound capable of donating sulfate ester groups to pulp, and examples thereof include sulfamic acid, sulfamic acid salts, and sulfuryl compounds having a sulfonyl group with two oxygen atoms covalently bonded to sulfur, and these compounds may be used alone or in combination of two or more. The sulfate ester group donating compound is preferably sulfamic acid, since it has a lower acidity than sulfuric acid and has a higher efficiency of introducing sulfate ester groups, is inexpensive, and is highly safe. Hereinafter, an example will be described in which sulfamic acid is used as the sulfate ester group donating compound and urea is used as the urea.

[0055] <Contact process> The contact step is a step of contacting the pulp with sulfamic acid and urea. This contact step is not particularly limited as long as it is a method that can cause the contact. For example, the pulp may be immersed in a reaction solution in which sulfamic acid and urea are dissolved in a solvent to impregnate the pulp with the reaction solution, or the reaction solution may be applied to the pulp, or the sulfamic acid and urea may be separately applied to, impregnated into, or sprayed onto the pulp. Among these, if a method of immersing the pulp in the reaction solution to impregnate the pulp with the reaction solution is used, the sulfamic acid and urea can be contacted uniformly with the pulp.

[0056] The solvent for dissolving sulfamic acid and urea is not particularly limited, and examples thereof include protic polar solvents such as water, ethanol, methanol, acetic acid, formic acid, 2-propanol, nitromethane, and aqueous ammonia, aprotic polar solvents such as acetone, ethyl acetate, tetrahydrofuran (THF), dimethylformamide (DMF), acetonitrile, dimethyl sulfoxide (DMSO), dimethyl sulfide (DMS), and dimethylacetamide (DMA), and non-polar solvents such as diethyl ether, benzene, toluene, hexane, chloroform, and 1,4-dioxane. The solvent may be used alone or in combination of two or more. In particular, water is preferred from the viewpoint of easily dissolving sulfamic acid and urea. The water may be tap water, but is preferably ion-exchanged water or pure water, and the same applies hereinafter.

[0057] The pulp that has been brought into contact with sulfamic acid and urea in this contacting step is sometimes called "reaction liquid-impregnated pulp."

[0058] <Contact amount of reaction solution> In contacting the reaction solution with the pulp, it is preferable to make the sulfamic acid and urea in the reaction solution have a predetermined ratio relative to the pulp. Specifically, the reaction solution is contacted so that the amounts of sulfamic acid and urea in the reaction solution relative to the pulp in the reaction solution-impregnated pulp when it is subjected to the reaction step are appropriate. More specifically, the contact amount of sulfamic acid relative to the pulp (solid content mass, which is the dry mass) in the reaction solution-impregnated pulp immediately before being subjected to the heating reaction in the reaction step is adjusted to be equal to or greater than the contact amount of urea.

[0059] For example, the reaction liquid is prepared so that the mixing ratio of sulfamic acid and urea, in terms of mass ratio, is such that the value (sulfamic acid / urea) obtained by dividing the parts by mass of sulfamic acid per 100 parts by mass of the solid content of pulp in the reaction liquid-impregnated pulp immediately before being subjected to the heating reaction by the parts by mass of urea per 100 parts by mass of the solid content of pulp in the reaction liquid-impregnated pulp immediately before being subjected to the heating reaction is 0.8 or more, 0.85 or more, or 1 or more.

[0060] Also, for example, the contact amount of sulfamic acid is adjusted to be 70 parts by mass or more, 100 parts by mass or more, or 200 parts by mass or more per 100 parts by mass of the solid content of the pulp in the reaction liquid-impregnated pulp immediately before being subjected to the heating reaction.

[0061] For example, the amount of urea contacted, i.e., the amount of urea contacted relative to the mass of solids in the reaction liquid-impregnated pulp immediately before being subjected to the heating reaction, is adjusted to 20 parts by mass or more, 30 parts by mass or more, or 50 parts by mass or more relative to 100 parts by mass of the solids of the pulp while maintaining the above-mentioned relationship with sulfamic acid. The upper limit of the amount of urea contacted is not particularly limited, and is, for example, 350 parts by mass or less, 300 parts by mass or less, or 250 parts by mass or less relative to 100 parts by mass of the solids of the pulp.

[0062] The contact amounts of sulfamic acid and urea per 100 parts by mass of the solid content of the pulp can be appropriately calculated depending on, for example, the state of the reaction liquid-impregnated pulp to be subjected to the reaction step.

[0063] <State of pulp impregnated with reaction liquid> The state of the reaction liquid-impregnated pulp to be subjected to the above-mentioned next reaction step may be, for example, the reaction liquid-impregnated pulp as it is, i.e., a state in which the pulp is in contact with the reaction liquid without actively removing water, or a state in which water has been actively removed from the pulp in contact with the reaction liquid.

[0064] The former reaction liquid-impregnated pulp (in a state where water is not actively removed) includes pulp in a state where the pulp is in contact with the reaction liquid (including, for example, a slurry state, etc.), and pulp that is removed from the state where the pulp is in contact with the reaction liquid and allowed to stand to prepare the reaction liquid.

[0065] Meanwhile, the latter reaction liquid-impregnated pulp (in a state where moisture has been actively removed) refers to pulp that has been in contact with the reaction liquid and has had moisture intentionally removed from it. For example, it includes pulp that has been prepared by removing the pulp from the reaction liquid and pulp in contact and naturally drying it by air drying or the like, pulp that has been in contact with the reaction liquid and pulp and then filtered and dehydrated, pulp that has been contacted with the reaction liquid and then further dried by air drying, pulp that has been filtered and dehydrated and then further dried by using a circulating air dryer, pulp that has been filtered and dehydrated and then further dried by using a heating dryer, pulp that has been contacted with the reaction liquid and then dried by using a circulating air dryer or a heating dryer, and the like.

[0066] In this way, the reaction liquid-impregnated pulp to be subjected to the reaction step may be one that has not been subjected to the active water removal described above, or one that has been actively removed to remove a certain amount of water. When removing water by drying, there is no problem even if the moisture content after drying is about 1%. In particular, by using the latter method, the moisture content in the reaction liquid-impregnated pulp to be subjected to the reaction step can be reduced, so that the reaction time in the heating reaction in the reaction step can be shortened. This has the advantage of improving the productivity of sulfate esterified pulp. In addition, by using the method of performing a dehydration treatment, there is the advantage that the reaction liquid-impregnated pulp can be prepared more efficiently than when a large amount of reaction liquid is treated.

[0067] When an active drying method is used, the reaction liquid-impregnated pulp may be dried until its moisture content reaches about 1%, or the moisture may be removed by drying until the pulp reaches an absolutely dry state with a moisture content significantly lower than 1%.

[0068] In this specification, the term "wet state" refers to reaction liquid-impregnated pulp that has a moisture content of 1% or more and is not in an absolute dry state. For example, the term "wet state" may refer to pulp that is still impregnated with the reaction liquid, pulp that has been dehydrated to a certain extent, and pulp that has been dried to a certain extent.

[0069] In addition, in this specification, bone dry means a state in which the moisture content is reduced to less than 1% by, for example, reducing the pressure in a desiccator containing a desiccant such as calcium chloride or diphosphorus pentoxide, or by subjecting the material to a long-term heat drying treatment.

[0070] Therefore, when the latter method described above (a reaction method in which active moisture removal is performed) is used in the contact step, a method may be used in which the moisture content of the reaction liquid-impregnated pulp is brought to a non-bone-dry state, or a method may be used in which the moisture content is brought to a bone-dry state, but it is preferable to use a method in which the moisture content is brought to a non-bone-dry state.

[0071] In this specification, the moisture content of the reaction liquid-impregnated pulp is calculated using the following formula. Moisture content of reaction liquid-impregnated pulp (%) = 100 - (mass of solid content of reaction liquid-impregnated pulp (g) / mass of reaction liquid-impregnated pulp at the time of moisture content measurement (g)) x 100 = {(mass of reaction liquid-impregnated pulp at the time of moisture content measurement (g) - mass of solid content of reaction liquid-impregnated pulp (g)) / mass of reaction liquid-impregnated pulp at the time of moisture content measurement (g)} x 100

[0072] The solid content mass (g) of the reaction liquid impregnated pulp in the above formula refers to the dry mass of the reaction liquid impregnated pulp. Specifically, it refers to the dry mass adjusted to a constant weight by drying the sample at 105°C using a dryer or the like. For example, the reaction liquid impregnated pulp is placed in a dryer and dried under specified drying conditions (e.g., 105°C, 2 hours) and the mass is measured, so that the mass of the reaction liquid impregnated pulp after moisture has been removed (i.e., the mass of the reaction liquid impregnated pulp that is not removed under the drying conditions. For example, the mass of the reaction liquid impregnated pulp that contains the reagents in the pulp and reaction liquid) can be calculated. In addition, the constant weight refers to a state in which the moisture in the atmosphere in the treatment facility and the moisture in the raw material do not appear to flow in or out. Specifically, it refers to a state in which the change in the mass between two consecutive measurements after drying for a certain period of time (e.g., 2 hours) is within 1% of the mass at the start of drying (however, the second mass measurement should be at least half the drying time required for the first measurement).

[0073] The state of the pulp when it is brought into contact with the reaction liquid is not particularly limited, and may be, for example, in a dry state or a wet state (i.e., a moist state).

[0074] <Pre-drying process in the contact process> In the above example, the method for preparing the reaction liquid-impregnated pulp in the contact step was described, in which the reaction liquid-impregnated pulp in the contact step is prepared by actively removing moisture. When using a method for removing moisture while heating (pre-drying step) in this method (for example, when the reaction liquid and the pulp in contact are directly heated and dried, or when the dehydrated pulp is heated and dried), it is desirable to adjust the heating temperature to a predetermined temperature or lower. The drying temperature in this pre-drying step is not particularly limited, but is preferably adjusted to a temperature at which the moisture contained in the reaction liquid-impregnated pulp and the moisture in the surroundings can be removed and the reaction does not proceed. For example, the drying temperature in the pre-drying step can be adjusted so that the atmospheric temperature of the reaction liquid-impregnated pulp is 100°C or lower. On the other hand, from the viewpoint of workability, it is preferable to adjust the temperature to 50°C or higher. Therefore, the drying temperature in the pre-drying step in the contact step is preferably 50°C to 100°C, or 70°C to 100°C.

[0075] <Moisture adjustment process during contact process> The contact step may include a moisture adjustment step in which the moisture content of the pulp to be contacted with the reaction liquid is adjusted to fall within a predetermined range. This moisture adjustment step is a step in which the pulp is adjusted by drying or humidifying so that the moisture content of the pulp is a predetermined moisture content. By including this moisture adjustment step, the moisture content in the pulp when it is contacted with the reaction liquid or the like can be made somewhat uniform, which may improve product stability in continuous operation. In addition, there is an advantage in that storage properties can be improved by drying the pulp to a certain extent to reduce the moisture content (for example, the moisture content is 1% to 10%).

[0076] <Reaction process> As described above, the reaction liquid-impregnated pulp prepared in the contact step is subjected to the next reaction step. This reaction step is a step in which cellulose fibers contained in the reaction liquid-impregnated pulp provided from the contact step are reacted with sulfamic acid and urea to replace at least a part of the hydroxyl groups in the cellulose fibers with sulfate ester groups, thereby introducing sulfate ester groups into the cellulose fibers contained in the pulp. That is, this reaction step is a step in which a reaction is carried out to replace at least a part of the hydroxyl groups in the cellulose fibers contained in the reaction liquid-impregnated pulp with sulfate ester groups.

[0077] This reaction step is not particularly limited as long as it is a method capable of replacing at least a part of the hydroxyl groups of the cellulose fibers in the reaction solution-impregnated pulp with sulfate ester groups, and for example, a method of accelerating the reaction by heating the reaction solution-impregnated pulp can be used. Hereinafter, the reaction will be described by taking the case where the reaction is carried out by this heating method as an example.

[0078] <Reaction temperature in the reaction process> The reaction temperature in the reaction step is not particularly limited, but is preferably a temperature at which sulfate ester groups can be introduced into the cellulose fibers constituting the pulp while suppressing thermal decomposition and hydrolysis of the fibers. For example, the atmospheric temperature of the reaction liquid-impregnated pulp subjected to the reaction step is adjusted to 100°C to 200°C, 120°C to 200°C, 120°C to 180°C, or 120°C to 160°C. If the atmospheric temperature during heating is 200°C or less, thermal decomposition and discoloration of the fibers can be suppressed.

[0079] The heater or the like used in the reaction step is not particularly limited, and for example, a heater capable of directly or indirectly heating the reaction liquid-impregnated pulp after the contact step while satisfying the above-mentioned requirements can be used, and a known dryer, reduced pressure dryer, microwave heating device, autoclave, infrared heating device, hot pressing method using a heat press machine (e.g., AH-2003C manufactured by AS ONE Co., Ltd.) can be used. In particular, from the viewpoint of operability, it is preferable to use a circulating air dryer since gas may be generated in the reaction step.

[0080] <Reaction time in the reaction process> The heating time (i.e., reaction time) when the heating method is used as the reaction step is not particularly limited, but is, for example, 1 minute or more, 5 minutes or more, 10 minutes or more, or 15 minutes or more when the reaction temperature is adjusted to be within the above range, and from the viewpoints of operability and cost, it is 5 minutes to 300 minutes, or 5 minutes to 120 minutes.

[0081] By carrying out the above steps, sulfated pulp can be prepared.

[0082] <Cleaning process after reaction process> The reaction step may be followed by a washing step of washing the sulfated pulp. The sulfated pulp has an acidic surface due to the effect of sulfamic acid (a sulfate ester group donor compound). In addition, unreacted reaction liquid is still present. For this reason, if a washing step is provided to completely terminate the reaction and remove excess reaction liquid to neutralize the reaction, the handling properties can be improved.

[0083] This washing step is not particularly limited, and may be any step that can make the sulfated pulp nearly neutral. For example, a method of washing the sulfated pulp with pure water or the like until it becomes neutral may be used. Alternatively, neutralization washing may be performed using an alkaline solution or the like. When such neutralization washing is performed, examples of the alkaline compound contained in the alkaline solution include inorganic alkaline compounds and organic alkaline compounds. Examples of the inorganic alkaline compounds include hydroxides, carbonates, and phosphates of alkali metals. Examples of the organic alkaline compounds include ammonia, aliphatic amines, aromatic amines, aliphatic ammonium, aromatic ammonium, heterocyclic compounds, and hydroxides of heterocyclic compounds.

[0084] The method for separating the sulfated pulp in the washing step is not particularly limited, and may be any method as long as the sulfated pulp and the washing water can be separated by filtration. For example, the sulfated pulp after the reaction may be washed using a stainless steel sieve with an opening size of 243 μm (70 mesh) to 20 μm (635 mesh), 132 μm (120 mesh) to 45 μm (300 mesh), or 75 μm (200 mesh) to 45 μm (300 mesh).

[0085] The method for preparing the carboxylated pulp is a method for preparing the carboxylated pulp by oxidizing a pulp (e.g., wood pulp) in a reaction solution containing an oxidizing agent and an oxidation promoter (co-oxidizing agent) using TEMPO as a catalyst. In addition to or instead of TEMPO, a derivative of TEMPO (e.g., 4-acetamido-TEMPO, 4-carboxyl-TEMPO, 4-phosphonooxy-TEMPO, etc.) may be used as the catalyst.

[0086] The amount of the catalyst used is not particularly limited, but is, for example, 1 mmol to 5 mmol, or 2 mmol to 5 mmol, per 5 g of the pulp.

[0087] Examples of the oxidizing agent include hypohalous acid, hypohalous acid salts, halous acid, halous acid salts, perhalogen acid, perhalogen acid salts, hydrogen peroxide, and perorganic acids. One type may be used alone, or two or more types may be used in combination. Among them, sodium hypochlorite (NaClO), sodium hypobromite, and the like are preferred because they are inexpensive. The amount of the oxidizing agent used may be appropriately selected within a range in which the oxidation treatment can proceed.

[0088] Examples of the oxidation promoter (co-oxidizing agent) include alkali metal bromides and alkali metal iodides, and one type may be used alone or two or more types may be used in combination. Among them, sodium bromide (NaBr) is preferred.

[0089] The amount of the pro-oxidant (co-oxidant) used is not particularly limited, but for example, it is preferable that the molar ratio R (amount of pro-oxidant (co-oxidant) used (mmol) / amount of catalyst used (mmol)) with respect to the amount of the catalyst used is R=1 to 5, or R=1 to 2.5.

[0090] The dispersion medium for the pulp in the reaction liquid is not particularly limited, and examples thereof include protic polar dispersion mediums such as water, ethanol, methanol, acetic acid, formic acid, 2-propanol, nitromethane, and aqueous ammonia, aprotic polar dispersion mediums such as acetone, ethyl acetate, tetrahydrofuran (THF), dimethylformamide (DMF), acetonitrile, dimethyl sulfoxide (DMSO), dimethyl sulfide (DMS), and dimethylacetamide (DMA), and non-polar dispersion mediums such as dimethyl ether, benzene, toluene, hexane, chloroform, and 1,4-dioxane. The dispersion medium may be used alone or in combination of two or more kinds. Among these, water is preferred from the viewpoint of handling.

[0091] In the oxidation treatment, the conditions such as the reaction temperature, the pH of the reaction solution, the reaction time, and the pressure are not particularly limited and may be appropriately selected. The oxidation treatment proceeds smoothly and efficiently even under mild conditions, so the reaction temperature may be about 15°C to 30°C. In addition, in order to prevent the oxidation treatment from being hindered by a decrease in the pH of the reaction solution accompanying the introduction of carboxyl groups into the pulp, an alkaline solution such as an aqueous sodium hydroxide solution may be added to maintain the pH of the reaction solution at about 9 to 12, or 10 to 11. It is desirable to carry out the oxidation treatment until the decrease in the pH of the reaction solution is no longer observed, but from the viewpoints of the inhibition of fiber shortening and production efficiency, the reaction time is preferably about 2 hours.

[0092] In this manner, the carboxylated pulp can be prepared. After the oxidation treatment, the catalyst and other components used may be removed by washing with water or the like.

[0093] The method for preparing the phosphoric acid esterified pulp is a method in which a phosphoric acid ester group donor compound described below is reacted with pulp (e.g., wood pulp) in the presence of at least one of urea and a urea derivative (hereinafter referred to as "urea, etc.") to replace at least a part of the hydroxyl groups of the pulp with phosphoric acid ester groups. The urea derivative is the same as that used in the method for preparing the sulfated pulp described above.

[0094] The phosphate ester group donor compound is at least one of a compound having a phosphate group and a salt thereof. The compound having a phosphate group is not particularly limited, but examples thereof include phosphoric acid, a lithium salt of phosphoric acid, a sodium salt of phosphoric acid, a potassium salt of phosphoric acid, and an ammonium salt of phosphoric acid. Examples of the lithium salt of phosphoric acid include lithium dihydrogen phosphate, dilithium hydrogen phosphate, trilithium phosphate, lithium pyrophosphate, and lithium polyphosphate. Examples of the sodium salt of phosphoric acid include sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, and sodium polyphosphate. Examples of the potassium salt of phosphoric acid include potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate, and potassium polyphosphate. Examples of the ammonium salt of phosphoric acid include ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, and ammonium polyphosphate. Among these, phosphoric acid, sodium salt of phosphoric acid, potassium salt of phosphoric acid, and ammonium salt of phosphoric acid are preferred from the viewpoints of high introduction efficiency of phosphate ester group, easy improvement of defibration efficiency in the fine processing step described later, low cost, and ease of industrial use. Hereinafter, an example will be described in which ammonium dihydrogen phosphate is used as the phosphate ester group donor compound and urea is used as the urea or the like.

[0095] It is preferable to use ammonium dihydrogen phosphate as an aqueous solution, since this increases the uniformity of the reaction and the efficiency of introducing the phosphate ester group. The pH of the aqueous solution of ammonium dihydrogen phosphate is not particularly limited, but is preferably 7 or less, since this increases the efficiency of introducing the phosphate ester group, and is more preferably 3 to 7, from the viewpoint of suppressing hydrolysis of the pulp.

[0096] The amount of ammonium dihydrogen phosphate added to the pulp is not particularly limited, but is, in terms of phosphorus atom weight, for example, 0.5% by mass to 100% by mass, 1% by mass to 50% by mass, or 2% by mass to 30% by mass relative to the pulp. If the amount of phosphorus atoms added to the pulp is within the above range, the yield of phosphorylated pulp can be further increased.

[0097] Urea is preferably used as an aqueous solution, similar to ammonium dihydrogen phosphate, and an aqueous solution in which both ammonium dihydrogen phosphate and urea are dissolved is preferably used, since this enhances the uniformity of the reaction. The amount of urea added to the pulp is not particularly limited, but is, for example, 1% by mass to 300% by mass.

[0098] In addition to ammonium dihydrogen phosphate and urea, amides or amines may be included in the reaction system. Examples of amides include formamide, dimethylformamide, acetamide, and dimethylacetamide. Examples of amines include methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, and hexamethylenediamine. Among these, triethylamine is known to act as a particularly good reaction catalyst.

[0099] In the reaction, a heat treatment may be performed. The heat treatment temperature may be selected so long as it is possible to efficiently introduce a phosphoric acid ester group while suppressing the thermal decomposition and hydrolysis reaction of the pulp, and is, for example, 50°C to 250°C, or 100°C to 200°C. For heating, a reduced pressure dryer, an infrared heater, a microwave heater, an oven using a blower, or the like may be used. The heat treatment time is not particularly limited, and is, for example, 1 minute to 300 minutes, or 1 minute to 200 minutes.

[0100] Sulfated CNF, carboxylated CNF and phosphated CNF can be obtained, for example, by subjecting the sulfated pulp, carboxylated pulp and phosphated pulp prepared as described above to a refining treatment step in which the pulp is refined.

[0101] <Micronization process> The micronization process is a process of micronizing sulfated pulp, carboxylated pulp, or phosphated pulp to obtain fine fibers of a predetermined size (for example, nano-level). The processing device used in this micronization process is not particularly limited as long as it has the above-mentioned function. For example, the processing device may be, but is not limited to, a low-pressure homogenizer, a high-pressure homogenizer, a grinder (stone-type grinder), a ball mill, a cutter mill, a jet mill, a single-screw extruder, a twin-screw extruder, an ultrasonic agitator, a household mixer, etc. Among these, it is desirable to use a high-pressure homogenizer because it can apply a force uniformly to the material and is excellent in homogenization.

[0102] In the case where a high-pressure homogenizer is used in the micronization process, the sulfated pulp, carboxylated pulp, or phosphated pulp is supplied in a state of being dispersed in an aqueous dispersion medium such as water. In the following, the dispersion liquid in which the sulfated pulp, carboxylated pulp, or phosphated pulp is dispersed may be referred to as a slurry. The solid content concentration of the sulfated pulp, carboxylated pulp, or phosphated pulp in this slurry is not particularly limited and is, for example, 0.1% by mass to 20% by mass.

[0103] For example, if a slurry containing sulfated pulp, carboxylated pulp, or phosphated pulp adjusted to a solids concentration of 0.5% by mass is fed to a processing device such as a high-pressure homogenizer, a dispersion liquid containing sulfated CNF, carboxylated CNF, or phosphated CNF at the same solids concentration dispersed in an aqueous dispersion medium can be obtained. In this case, a dispersion liquid with a solids concentration of 0.5% by mass can be obtained.

[0104] The water retention of the sulfated pulp, carboxylated pulp, or phosphated pulp to be subjected to the refining process is not particularly limited, but is preferably adjusted so as to be easily refined by the above-mentioned device. For example, from the viewpoint of refining process efficiency and energy consumption reduction, it is desirable to use sulfated pulp, carboxylated pulp, or phosphated pulp prepared to have a high water retention. From this viewpoint, it is preferable to use sulfated pulp, carboxylated pulp, or phosphated pulp prepared to have a water retention of 150% or more, 200% or more, 250% or more, 300% or more, or 500% or more. From the viewpoint of the recovery rate of sulfated CNF, carboxylated CNF, and phosphated CNF, the water retention is, for example, 10,000% or less. Thus, from the viewpoint of refining treatment efficiency and recovery rate, the water retention of the sulfated pulp, carboxylated pulp or phosphated pulp subjected to the refining treatment step is, for example, 150% to 10,000%, 200% to 10,000%, 220% to 10,000%, 250% to 5,000%, or 250% to 2,000%.

[0105] The above-mentioned dispersion of sulfated CNF, carboxylated CNF, or phosphated CNF is dried to obtain sulfated CNF, carboxylated CNF, or phosphated CNF. The drying method is not particularly limited, and conventionally known methods such as natural drying, heat drying, reduced pressure drying, vacuum drying, and spray drying can be used. The temperature during drying is, for example, 120° C. or less from the viewpoint of preventing discoloration, etc.

[0106] The cellulose fiber may be a dry powder prepared by freeze-drying. The method for preparing the dry powder is not particularly limited, and may be a conventionally known method, such as the method described in the Examples below.

[0107] The amount of the cellulose fiber in the total amount of the anti-slip agent (cellulose fiber ratio) is 50% by mass or less. Although the mechanism is unclear, as demonstrated in the examples described later, by including 50% by mass or less of the cellulose fiber in the anti-slip agent, water can be absorbed in a short time. The cellulose fiber ratio may be, for example, 20% by mass or less, 10% by mass or less, 5% by mass or less, 2% by mass or less, or 1% by mass or less. If the cellulose fiber is unmodified or at least a part of the hydroxyl groups of the cellulose is substituted with a sulfate ester group, and the cellulose fiber ratio is 10% by mass or less, the average particle size of the anti-slip agent is the same as or smaller than the currently widely used anti-slip agent (magnesium carbonate powder, etc.), and it can be used without discomfort even if it is replaced therewith. The average particle size of the anti-slip agent can be measured, for example, by the method described in the examples described later. The lower limit of the cellulose fiber ratio is not particularly limited, but is, for example, 0.01% by mass or more.

[0108] The anti-slip agent can be produced, for example, by uniformly mixing the base powder, the cellulose fiber, and other additives as necessary, by a conventionally known method. For example, a home mixer can be used for the mixing. Therefore, the anti-slip agent can be produced very easily by simply preparing the base powder and the cellulose fiber.

[0109] The anti-slip agent can be widely used in various sports, such as sport climbing (bouldering), track and field, gymnastics, baseball, softball, golf, etc. EXAMPLES

[0110] The base powders shown in Tables 1 to 5 and cellulose fibers were mixed for 3 minutes in a household mixer (manufactured by Panasonic Corporation, model number: MX-701) to obtain anti-slip agents of Examples 1-1 to 1-8, 2-1 to 2-15, 3-1, 3-2, 4-1, 4-2, 5-1, and 5-2. Example 1-1 is an example in which magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd. was used as the base powder, and dry powder of unmodified pulp (softwood bleached kraft pulp (NBKP) with an average fiber length of 2.54 mm manufactured by Marusumi Paper Co., Ltd.) was used as the cellulose fiber. Examples 1-2 to 1-6 are examples in which magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd. was used as the base powder, and dry powder of sulfated pulp described below was used as the cellulose fiber. Example 1-7 is an example in which magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd. is used as the base powder, and a dry powder of carboxylated pulp described later is used as the cellulose fiber. Example 1-8 is an example in which magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd. is used as the base powder, and a dry powder of phosphoric esterified pulp described later is used as the cellulose fiber. Examples 2-1 to 2-3 are examples in which magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd. is used as the base powder, and a dry powder of unmodified CNF (cellulose nanofiber, fine cellulose fiber, manufactured by Sugino Machine Co., Ltd., model number: Wfo-10002) is used as the cellulose fiber. Examples 2-4 to 2-11 are examples in which magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd. is used as the base powder, and a dry powder of sulfated CNF described later is used as the cellulose fiber. Examples 2-12 and 2-13 are examples in which magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd. is used as the base powder, and a dry powder of carboxylated CNF described later is used as the cellulose fiber. Examples 2-14 and 2-15 are examples using magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd. as the base powder and dry powder of phosphate-esterified CNF described below as the cellulose fiber. Examples 3-1 and 3-2 are examples using magnesium carbonate manufactured by Nishi Sports Co., Ltd. as the base powder and dry powder of sulfate-esterified CNF described below as the cellulose fiber. Examples 4-1 and 4-2 are examples using magnesium carbonate manufactured by Black Diamond Co., Ltd. (trade name: White Gold) as the base powder and dry powder of sulfate-esterified CNF described below as the cellulose fiber.Examples 5-1 and 5-2 are examples using magnesium carbonate (product name: Black Gold) manufactured by Black Diamond Co., Ltd. as the base powder and dry powder of sulfated CNF described below as the cellulose fiber. Comparative Examples 1-1, 2-1, 3-1, 4-1, and 5-1 are examples using the base powders used in Examples 1-1 to 1-8, 2-1 to 2-15, 3-1 and 3-2, 4-1 and 4-2, 5-1, and 5-2 alone, respectively.

[0111] The average particle size (μm) and water absorption time (seconds) of the anti-slip agents shown in Tables 1 to 5 were measured by the following method.

[0112] (average particle size of anti-slip agent) The average particle size of the anti-slip agent was measured using a laser diffraction scattering type particle size distribution measuring instrument (manufactured by Seishin Enterprise Co., Ltd., model: LMS-2000e). The measurement range was 0.01 μm to 500 μm. The average particle size in this specification is the volume average diameter.

[0113] (Water absorption time of anti-slip agent) 2 g of the anti-slip agent was pressed (50 MPa) with a press machine (model: HC300-05, manufactured by AS ONE Corporation) to prepare a measurement sample. 100 μL of pure water (23° C.) was dropped onto the surface of the measurement sample, and the time (seconds) until the pure water completely soaked into the measurement sample was measured. As the pure water, home-prepared pure water with an electrical conductivity of >0.2 μS / cm was used, and the same applies hereinafter.

[0114] The sulfated pulp, carboxylated pulp, phosphated pulp, sulfated CNF, carboxylated CNF and phosphated CNF shown in Tables 1 to 5 were prepared as follows.

[0115] (Preparation of sulfated pulp) The unmodified pulp (hereinafter sometimes simply referred to as "pulp") described above was washed with a large amount of pure water, and then the water was drained using a sieve with an opening of 75 μm (200 mesh). The solid content of a portion of the pulp thus obtained was measured, and found to be 21.6% by mass. The wet pulp was then spread on an aluminum pad, placed in a dryer in an atmosphere of 105°C, and dried for about 1 hour until the moisture content reached about 1%.

[0116] <Contact process> 1000 g of the reaction solution was added to 20 g of pulp (solid content mass), and the reaction solution was impregnated into the pulp. The reaction solution used was an aqueous solution in which sulfamic acid and urea were mixed in a concentration ratio (g / L) of sulfamic acid:urea=200 g / L:200 g / L. The sulfamic acid used was a product of Fuso Chemical Co., Ltd. with a purity of 99.8%, and the urea used was a product of Fujifilm Wako Pure Chemical Co., Ltd. with a purity of 99.0%, model number: special grade reagent.

[0117] The pulp impregnated with the reaction solution was dehydrated by suction filtration and spread on an aluminum tray. The aluminum tray was then placed in a dryer at 80°C to dry, preparing a pulp impregnated with the reaction solution. Filter paper (manufactured by Advantech, model number: No. 2) was used for the suction filtration.

[0118] <Reaction process> The reaction solution-impregnated pulp was subjected to a heating reaction using a dryer, the temperature of the thermostatic chamber of the dryer was set to 120° C., and the heating time was set to 25 minutes.

[0119] <Cleaning process after reaction process> The pulp after the reaction step was neutralized on a sieve with an opening of 45 μm (300 mesh) and then washed with pure water. An aqueous solution of sodium hydrogen carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the neutralizing agent. In this way, a sulfated pulp having an introduction amount of sulfate ester groups of 1.37 mmol / g was prepared.

[0120] (Preparation of Carboxylated Pulp) 25 g of pulp obtained in the same manner as in the preparation of sulfated pulp described above was added to a reaction solution in which 0.023 g of TEMPO and 0.514 g of NaBr were dissolved in 480 g of pure water, and the mixture was stirred for 10 minutes. Then, 34 mL of an aqueous NaClO solution was added to the reaction solution, and the pH was maintained at 10.5 by adding 1 M hydrochloric acid and 1 M aqueous sodium hydroxide solution, and the mixture was stirred for 2 hours. The aqueous NaClO solution was treated by adding ethanol, and the mixture was washed with a large amount of water to obtain a carboxylated pulp with a carboxyl group content of 1.19 mmol / g. The TEMPO used was Fujifilm Wako Pure Chemical Industries, Ltd., purity 98+%, the NaBr used was Fujifilm Wako Pure Chemical Industries, Ltd., model number: special grade, the NaClO aqueous solution used was Fujifilm Wako Pure Chemical Industries, Ltd., effective chlorine concentration 5.0+%, the 1 M hydrochloric acid and 1 M sodium hydroxide aqueous solution used were Fujifilm Wako Pure Chemical Industries, Ltd., volumetric grade, and the ethanol used was Fujifilm Wako Pure Chemical Industries, Ltd., purity 95.1 to 96.9 vol%.

[0121] (Preparation of Phosphate-Esterified Pulp) The reaction liquid was added to 80 g of pulp obtained in the same manner as in the preparation of the sulfated pulp described above, and the pulp was impregnated with the reaction liquid. The reaction liquid used was an aqueous solution prepared by dissolving 13.8 g of ammonium dihydrogen phosphate and 15 g of urea in 120 g of water.

[0122] The pulp impregnated with the reaction solution was dehydrated by suction filtration and spread on an aluminum tray. The aluminum tray was then placed in a dryer at 80°C to dry, preparing a pulp impregnated with the reaction solution. Filter paper (manufactured by Advantech, model number: No. 2) was used for the suction filtration.

[0123] The reaction solution-impregnated pulp was subjected to a heating reaction using a dryer, the temperature of the thermostatic chamber of the dryer was set to 140° C., and the heating time was set to 30 minutes.

[0124] The pulp after the reaction was neutralized on a sieve with an opening of 45 μm (300 mesh) and then washed with pure water. An aqueous solution of sodium hydrogen carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the neutralizing agent. In this way, a phosphated pulp with an introduction amount of phosphate ester groups of 1.76 mmol / g was prepared.

[0125] (Preparation of sulfated CNF, carboxylated CNF, and phosphated CNF) The sulfated pulp, carboxylated pulp, or phosphated pulp was subjected to defibration treatment five times using a high-pressure homogenizer (Nano-Veita, manufactured by Yoshida Kikai Kogyo Co., Ltd., pressure: 60 MPa) to obtain a dispersion of 1.0 mass% sulfated CNF, carboxylated CNF, or phosphated CNF.

[0126] (Preparation of dry powder) 20 g of a 1.0 mass% dispersion of sulfated CNF was placed in a plastic petri dish (manufactured by AS ONE Corporation, φ55×17 mm, product name: Azunol Petri dish) and stored at -40°C for 1 day to freeze. This frozen sample was placed in a freeze dryer (manufactured by AS ONE Corporation, model number: FDU-12AS) and freeze-dried for 1 to 2 days to obtain a dry powder of sulfated CNF. The moisture content of the sulfated CNF after freeze-drying was 10 mass% or less. The dry powders of cellulose fibers other than sulfated CNF used in each example and comparative example were also prepared by the same freeze-drying process.

[0127] Tables 1 to 5 show the base powder and cellulose fiber used in Examples 1-1 to 1-8 and Comparative Example 1-1, Examples 2-1 to 2-15 and Comparative Example 2-1, Examples 3-1 and 3-2 and Comparative Example 3-1, Examples 4-1 and 4-2 and Comparative Example 4-1, Examples 5-1 and 5-2 and Comparative Example 5-1, the blending ratio (mass ratio) of the base powder (M) to the cellulose fiber (S) in the anti-slip agent, the average particle size (μm) of the anti-slip agent, and the water absorption time (seconds).

[0128] [Table 1]

[0129] As shown in Table 1, Examples 1-1 to 1-8 had shorter water absorption times than Comparative Example 1-1, which used the same type of base powder (magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd.) alone. Moreover, Examples 1-2 to 1-6, which used sulfated pulp, had shorter water absorption times than Example 1-1, which used unmodified pulp, Example 1-7, which used carboxylated pulp, and Example 1-8, which used phosphated pulp. Furthermore, Examples 1-1 to 1-5, in which the blending amount of unmodified pulp or sulfated pulp was 10 mass% or less, had average particle sizes comparable to those of Comparative Example 1-1, which used the same type of magnesium carbonate alone.

[0130] [Table 2]

[0131] As shown in Table 2, in Examples 2-1 to 2-15, the water absorption time was shorter than that of Comparative Example 2-1 in which the same type of base powder (magnesium carbonate manufactured by Naikai Salt Industry Co., Ltd.) was used alone. In addition, in Examples 2-6 and 2-9 in which sulfated CNF was used, the water absorption time was shorter than that of Examples 2-1, 2-2, 2-12 and 2-13, and 2-14 and 2-15 in which the same amount of unmodified CNF, carboxylated CNF, or phosphated CNF was used. Furthermore, in Examples 2-1, 2-2, and 2-4 to 2-9 in which the amount of unmodified CNF or sulfated CNF was 10 mass% or less, the average particle size was approximately the same as that of Comparative Example 2-1 in which the same type of magnesium carbonate was used alone.

[0132] [Table 3]

[0133] As shown in Table 3, in Examples 3-1 and 3-2, the water absorption time was shorter than that in Comparative Example 3-1 in which the same type of base powder (magnesium carbonate manufactured by Nishi Sports Co., Ltd.) was used alone.

[0134] [Table 4]

[0135] As shown in Table 4, in Examples 4-1 and 4-2, the water absorption time was shorter than that in Comparative Example 4-1 in which the same type of base powder (magnesium carbonate manufactured by Black Diamond, product name: White Gold) was used alone.

[0136] [Table 5]

[0137] As shown in Table 5, in Examples 5-1 and 5-2, the water absorption time was shorter than that in Comparative Example 5-1 in which the same type of base powder (magnesium carbonate manufactured by Black Diamond, product name: Black Gold) was used alone.

[0138] The magnesium carbonate used in each example is sold by Naikai Salt Co., Ltd. for a wide range of general applications including track and field, by Nishi Sports Co., Ltd. for general track and field, and by Black Diamond Co., Ltd. for specialized sports climbing. According to the present invention, it was confirmed that the water absorption time can be shortened for magnesium carbonate (main powder) for any of these applications by using a specified amount of cellulose fiber in combination.

[0139] Although the present invention has been described above with reference to the embodiments and examples, the present invention is not limited to the above-mentioned embodiments and examples. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

Claims

1. The present invention includes a base powder and cellulose fibers, The anti-slip agent has a blending amount of the cellulose fibers of 50% by mass or less.

2. 2. The anti-slip agent according to claim 1, wherein the cellulose fibers have at least a portion of the hydroxyl groups of the cellulose ester substituted with sulfate ester groups.

3. The anti-slip agent according to claim 2 , wherein the blending amount of the cellulose fibers is 10% by mass or less.

4. The anti-slip agent according to any one of claims 1 to 3, wherein the base powder contains at least one of magnesium carbonate powder and calcium carbonate powder.

5. A method for producing an anti-slip agent, comprising the step of mixing a base powder with cellulose fibers, the anti-slip agent containing 50% by mass or less of the cellulose fibers.

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