Cellulose material

Abstract

To provide a cellulose material which has good recyclability even when it is used as an additive of a resin component.SOLUTION: There is provided a cellulose material, wherein an amount of an iron component detected by a triple quadrupole-inductively coupled plasma mass spectrometry measuring device exceeds 10 ppm and is 50 ppm or less. As for the cellulose material, preferably, an ash content after heating at 800°C for 2 hours is 0.13 wt.% or more with respect to 100 wt.% of the cellulose material before heating, or a thermogravimetry residual ratio at 500°C is 10% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cellulose material. [Background Art]

[0002] Cellulose materials such as powdered cellulose are used as reinforcing agents for resin materials such as rubber and plastic (for example, Patent Document 1). [Prior Art Literature] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2022-012875 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Incidentally, for environmental protection, the importance of chemical recycling of plastics has been attracting attention. When a resin material containing a cellulose material as in the above-mentioned conventional technology is recycled by a method called closed-loop recycling, the resin component and the cellulose component are usually separated in the process. However, cellulose materials have a disadvantage of having a low thermogravimetric residual ratio, making separation from resin materials difficult.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a cellulose material having good recyclability even when used as an additive for a resin component. [Means for Solving the Problem]

[0006] The present invention provides the following [1] to

[10] . [1] A cellulose material, wherein the amount of an iron component detected by a triple quadrupole-inductively coupled plasma mass spectrometer is more than 10 ppm and 50 ppm or less. [2] The cellulose material according to [1], wherein the amount of ash after heating at 800°C for 2 hours is 0.13% by weight or more relative to 100% by weight of the cellulose material before heating. [3] The cellulose material according to [1] or [2], wherein the thermal weight retention rate at 500°C is 10% or more. [4] A cellulose material according to any one of items [1] to [3], wherein the average fiber width is 10 to 24 μm. [5] A cellulose material described in any one of items [1] to [4], which is powdered cellulose. [6] The cellulose material according to [5], wherein the average particle size of the powdered cellulose is 5 to 150 μm. Industrial additives containing cellulose materials as described in any one of items [7], [1], to [6]. A resin composition containing the cellulose material described in any one of items [8], [1], to [6]. A rubber composition containing the cellulose material described in any one of items [9], [1], to [6]. A molded article containing the cellulose material described in any one of items

[10] , [1], to [6]. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a cellulose material that exhibits a high thermal weight retention rate and has good recyclability of biomass material when mixed with resin. [Modes for carrying out the invention]

[0008] [1. Cellulose materials] Cellulose materials are materials whose main component is cellulose, and which also contain iron.

[0009] [1.1. Iron content] Cellulose materials contain iron components. The iron components may be bonded to the cellulose molecules of the cellulose material, or they may exist separately without being bonded (they can also be called a composition containing cellulose material). Iron components usually exist as iron atoms, compounds containing them, and derivatives. Examples of these include iron atoms (Fe), oxides (Fe2O3, Fe3O4), hydroxides (Fe(OH)2, Fe(OH)3), oxyhydroxides (FeO(OH)), chlorides (FeCl2, FeCl3), nitrates (Fe(NO)3), sulfates (FeSO4, Fe2(SO4)3), halides (Br, I), and complex compounds, with oxides usually being the main component.

[0010] In this specification, the iron content is a value detected by a triple quadrupole inductively coupled plasma (ICP) mass spectrometer. Specifically, it can be measured under the following conditions, and the values ​​in the examples were also measured using the method described below. Note that if the iron component is not iron atoms, the amount of iron component represents the amount of iron atoms. Model: Agilent 8800 (manufactured by Agilent Technologies, Inc.) Collision and reaction cell introduction gases: Helium and hydrogen Measurement m / z: Iron; 56 Internal standard element m / z: Rhodium; 103

[0011] The amount of iron in the cellulose material is usually greater than 10 ppm, preferably 10.5 ppm or more, and more preferably 11 ppm or more. This allows for the production of a cellulose material with a high thermal weight retention rate and excellent recyclability of biomass material when mixed with resin. The upper limit is usually 50 ppm or less, preferably 40 ppm or less, more preferably 30 ppm or less, even more preferably 29 ppm or less, 28 ppm or less, 27 ppm or less, or 26 ppm or less. This suppresses the inclusion of foreign matter in the resin when recycled. Therefore, the iron content of the cellulose material is usually greater than 10 ppm and less than or equal to 50 ppm, more preferably greater than 10 ppm and less than or equal to 40 ppm, even more preferably 10.5 to 30 ppm, even more preferably 11 to 29 ppm, 11 to 28 ppm, 11 to 27 ppm, or 11 to 26 ppm.

[0012] The amount of iron content can be adjusted by controlling the amount of iron content in the raw materials and the amount of iron content added during manufacturing.

[0013] [1.2. Amount of ash after heating] The cellulose material preferably contains ash after heating at 800°C for 2 hours. Ash is typically the non-organic component remaining after the raw material is ashed. The amount of ash after heating is preferably 0.13% or more by weight, or 0.14% or more by weight, and more preferably 0.15% or more, based on 100% by weight of the cellulose material before heating. This allows for the production of a cellulose material with a high thermal weight retention rate and excellent recyclability of the biomass material when mixed with resin. The upper limit is preferably 2.0% or less by weight, and more preferably 1.6% or less by weight. This helps to suppress the inclusion of foreign matter in the resin when recycled. Therefore, the amount of ash is preferably 0.13 to 2.0% or 0.14 to 2.0% by weight, and more preferably 0.15 to 1.6% by weight.

[0014] The ash content after heating at 800°C for 2 hours can be measured, for example, by a method in which a sample (with the sample weight measured in advance) is carbonized, then heated at 800°C for 2 hours for ashing, the weight of the residue after ashing is measured, and the ash content is calculated as the percentage ratio of the ashed residue to the sample weight.

[0015] [1.3. Thermogravimetric residual rate] The cellulose material can exhibit a high thermogravimetric residual rate. For example, the thermogravimetric residual rate after heating at 500°C is usually 10% or more, preferably 10.5% or more, more preferably 11% or more. The upper limit is preferably 35% by weight or less, more preferably 30% by weight or less. The thermogravimetric residual rate can be confirmed using a thermal analyzer as the percentage ratio of the weight after heating at 500°C to the weight before the start of heating.

[0016] [1.4. Morphology of Cellulose Material] Examples of the morphology of the cellulose material include powder form and fibrous form (microfibrils, nanofibers), with powdered cellulose being preferred.

[0017] [1.5. Powdered Cellulose] [Particle Size Distribution] The particle size distribution of powdered cellulose can be expressed as the particle sizes when the cumulative value of the volume cumulative distribution reaches 10%, 50%, and 90% (10% diameter, 50% diameter, 90% diameter, which are D10, D50, and D90 respectively). In the present specification, the particle size distribution is a value obtained by wet measurement (with ultrasonic irradiation), wet measurement (without ultrasonic irradiation), or dry measurement using the laser scattering method as the measurement principle.

[0018] The span of the particle size distribution is calculated by substituting D10, D50, and D90 obtained by each method into the following formula (1). Formula (1): Span of particle size distribution = ((D90)-(D10)) / (D50)

[0019] - Conditions for wet measurement (without ultrasonic irradiation) - In this specification, wet conditions (without ultrasonic irradiation) refer to conditions in which the particle size is measured directly after adding water to the sample without ultrasonic irradiation. The preferred ranges for D.10, D.50, D.90, and span under wet conditions (without ultrasonic irradiation) are as follows. Generally, the larger the particle size, the greater the tendency for the fibers to entangle. Furthermore, by staying within the following ranges, it is possible to appropriately improve the strength without impairing the properties of resins, rubbers, etc., when added to them. D.10 is usually 5 μm or more, 9.0 μm or more, or 10.0 μm or more, preferably 11.0 μm or more, and more preferably 11.5 μm or more. The upper limit is usually 40 μm or less or 25.0 μm or less, preferably 14.0 μm or less, and more preferably 13.0 μm or less. Therefore, it is usually 5 to 40 μm, 9.0 to 40.0 μm, or 10.0 to 25.0 μm, preferably 11.0 to 14.0 μm, and more preferably 11.5 to 13.0 μm. D.50 (average particle size) is usually 5 μm or more, 10.0 μm or more, 20.0 μm or more, or 25.0 μm or more, preferably 30.0 μm or more, or 34.0 μm or more, more preferably 36.0 μm or more, and even more preferably 38.0 μm or more (however, it is a value greater than D.10). This suppresses the increase in cohesiveness of powdered cellulose and the resulting decrease in powder flowability, thereby suppressing deterioration of workability. The upper limit is usually 150.0 μm or less, 100.0 μm or less, 90.0 μm or less, 70 μm or less, or 50.0 μm or less, preferably 450.0 μm or less, 44.0 μm or less, or 43.0 μm or less, more preferably 42.0 μm or less, and even more preferably 40.0 μm or less. This makes it possible to obtain powdered cellulose with a high thermal weight retention rate and excellent recyclability. Therefore, D.50 (average particle size) is typically 5.0-150.0 μm, 5.0-100.0 μm, 10.0-90.0 μm, 20.0-70.0 μm, or 25.0-50.0 μm, preferably 30.0-45.0 μm, 30.0-44.0 μm, or 34.0-43.0 μm, more preferably 36.0-42.0 μm, and even more preferably 38.0-40.0 μm. D.90 is typically 70.0 μm or more, or 75.0 μm or more, preferably 80.0 μm or more, 85.0 μm or more, or 90.0 μm or more, more preferably 95.0 μm or more, and even more preferably 100.0 μm or more (however, it is a value greater than D.50). The upper limit is typically 250.0 μm or less, 230.0 μm or less, or 220.0 μm or less, preferably 210.0 μm or less, or 200.0 μm or less, more preferably 195.0 μm or less, and even more preferably 190.0 μm or less. Therefore, typically the particle size is 70.0-250.0 μm, 70.0-230.0 μm, or 75.0-220.0 μm, preferably 80.0-210.0 μm, 85.0-200.0 μm, or 90.0-200.0 μm, more preferably 95.0-195.0 μm, and even more preferably 100.0-190.0 μm. The span of the particle size distribution is usually 1.5 or greater, preferably 1.7 or greater, more preferably 1.9 or greater, and even more preferably 2.0 or greater. The upper limit is usually 6.0 or less, preferably 5.5 or less, more preferably 5.0 or less, and more preferably 4.5 or less. Therefore, it is usually 1.5 to 6.0, preferably 1.7 to 5.5, more preferably 1.9 to 5.0, and more preferably 2.0 to 4.5.

[0020] -Wet measurement (with ultrasonic irradiation)- In this specification, wet conditions (with ultrasonic irradiation) refer to conditions in which the particle size is measured after adding water to the sample and then irradiating it with ultrasound. The preferred ranges for D.10, D.50, D.90, and span in the wet conditions (with ultrasound) are as follows. Generally, the larger the particle size, the greater the tendency for the fibers to entangle. Furthermore, by staying within the following ranges, it is possible to appropriately improve the strength without impairing the properties of resins, rubbers, etc., when added to them. D.10 is usually 1.0 μm or more, 3.0 μm or more, or 5.0 μm or more, preferably 9.0 μm or more, or 10.0 μm or more, more preferably 10.5 μm or more, and even more preferably 11.0 μm or more. The upper limit is usually 20.0 μm or less, or 16.0 μm or less, preferably 13.0 μm or less, and even more preferably 12.5 μm or less. Therefore, it is usually 1.0 to 20.0 μm, 3.0 to 16.0 μm, or 5.0 to 16.0 μm, preferably 9.0 to 13.0 μm or 10.0 to 13.0 μm, more preferably 10.5 to 12.5 μm, and even more preferably 11.0 to 12.5 μm. D.50 is typically 5.0 μm or more, 10.0 μm or more, or 20.0 μm or more, preferably 25.0 μm or more, 30.0 μm or more, or 32.0 μm or more, more preferably 34.0 μm or more, or 36.0 μm or more, and even more preferably 36.5 μm or more (provided it is a value greater than D.10). The upper limit is typically 70.0 μm or less, 60.0 μm or less, or 50.0 μm or less, preferably 45.0 μm or less, or 40.0 μm or less, more preferably 39.5 μm or less, and even more preferably 39.0 μm or less. Therefore, typically the particle size is 5.0-70.0 μm, 10.0-60.0 μm, or 20.0-50.0 μm, preferably 25.0-45.0 μm, 30.0-40.0 μm, or 32.0-40.0 μm, more preferably 34.0-39.5 μm, and even more preferably 36.0-39.0 μm or 36.5-39.0 μm. D.90 is typically 50.0 μm or more, 70.0 μm or more, or 90.0 μm or more, preferably 98 μm or more, more preferably 100.0 μm or more, and even more preferably 101.5 μm or more (however, it is a value greater than D.50). The upper limit is typically 210.0 μm or less, or 200.0 μm or less, preferably 200.0 μm or less, more preferably 195.0 μm or less, and even more preferably 190.0 μm or less. Therefore, D.90 is typically 50.0 to 210.0 μm, 60.0 to 200.0 μm, or 70.0 to 200.0 μm, preferably 80.0 to 195.0 μm, more preferably 90.0 to 190.0 μm, and even more preferably 100.0 to 190.0 μm. The span of the particle size distribution is usually 1.5 or greater, preferably 1.7 or greater, more preferably 1.9 or greater, and even more preferably 2.0 or greater. The upper limit is usually 5.0 or less, preferably 4.5 or less. Therefore, it is usually 1.5 to 5.0, preferably 1.7 to 4.5, and more preferably 1.9 to 4.5.

[0021] -Dry measurement- In this specification, dry measurement refers to the condition in which the particle size is measured directly without adding water to the sample. The preferred ranges for D.10, D.50, D.90, and span in the case of dry measurement are as follows. Generally, the larger the particle size, the greater the tendency for the fibers to entangle. Furthermore, by staying within the following ranges, it is possible to appropriately improve the strength without impairing the properties of resins, rubbers, etc., when added to them. D.10 is usually 1.0 μm or more, 3.0 μm or more, or 5.0 μm or more, preferably 7.0 μm or more, or 8.0 μm or more, more preferably 9.0 μm or more, and even more preferably 9.5 μm or more. The upper limit is usually 40.0 μm or less, or 20.0 μm or less, preferably 15.0 μm or less, more preferably 14.0 μm or less, and even more preferably 13.0 μm or less. Therefore, it is usually 1.0 to 40.0 μm, 3.0 to 20.0 μm, or 5.0 to 20.0 μm, preferably 7.0 to 15.0 μm or 8.0 to 15.0 μm, more preferably 9.0 to 14.0 μm, and even more preferably 9.5 to 13.0 μm. D.50 is typically 5.0 μm or more, 10.0 μm or more, or 15.0 μm or more, preferably 20.0 μm or more, 25.0 μm or more, or 30.0 μm or more, more preferably 33.0 μm or more, or 34.0 μm or more, and even more preferably 35.0 μm or more (provided it is a value greater than D.10). The upper limit is typically 100.0 μm or less, or 60.0 μm or less, preferably 52.5 μm or less, or 52.0 μm or less, and more preferably 51.5 μm or less. Therefore, D.50 is typically 5.0-100.0 μm, 10.0-60.0 μm, or 15.0-60.0 μm, preferably 20.0-52.5 μm, 25.0-52.5 μm, or 30.0-52.5 μm, more preferably 33.0-52.0 μm or 34.0-52.0 μm, and even more preferably 35.0-51.5 μm. D.90 is usually 80.0 μm or more, or 90.0 μm or more, preferably 93.0 μm or more, and more preferably 94.0 μm or more (however, it is a value greater than D.50). The upper limit is usually 310.0 μm or less, or 280.0 μm or less, preferably 260.0 μm or less, or 255.0 μm or less, and more preferably 251.0 μm or less. Therefore, D.90 is usually 80.0 to 310.0 μm or 90.0 to 280.0 μm, preferably 93.0 to 260.0 μm or 93.0 to 255.0 μm, and more preferably 94.0 to 251.0 μm. The span of the particle size distribution is usually 1.5 or greater, preferably 1.7 or greater, more preferably 1.8 or greater, and even more preferably 2.0 or greater. The upper limit is usually 9.0 or less, preferably 7.0 or less, more preferably 6.0 or less, and even more preferably 5.0 or less. Therefore, the span of the particle size distribution is usually 1.5 to 9.0, preferably 1.7 to 7.0, more preferably 1.8 to 6.0, and even more preferably 2.0 to 5.0.

[0022] [Average fiber width (μm), average fiber length (mm), average fiber length / average fiber width] The average fiber width (short axis) refers to the average of the minimum values ​​perpendicular to the major axis of the fiber width of powdered cellulose. The average fiber length (long axis) refers to the average of the maximum lengths of the fiber widths of powdered cellulose.

[0023] The average fiber width is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more. The upper limit is preferably 35 μm or less, more preferably 30 μm or less, and even more preferably 24 μm or less. Therefore, the average fiber width is preferably 10 to 35 μm, more preferably 15 to 30 μm, and even more preferably 20 to 24 μm.

[0024] The average fiber length is preferably 0.05 mm or more, more preferably 0.06 mm or more. The upper limit is preferably 0.3 mm or less, more preferably 0.25 mm or less. Therefore, the average fiber length is preferably 0.05 to 0.3 mm, more preferably 0.06 to 0.25 mm.

[0025] The average fiber length / average fiber width (L / D) of powdered cellulose is preferably 2.5 to 12.0, and more preferably 3.0 to 11.5. Generally, the larger the L / D, the greater the tendency for the fibers to entangle. Furthermore, being within the above range allows for appropriate improvement of strength without impairing the properties of resins, rubbers, etc., when added to them.

[0026] The average fiber length and average fiber width can be measured using the ABB Fiber Tester Plus, and the L / D ratio is calculated from these measurements.

[0027] [1.6. Fibrous Cellulose] Fibrous cellulose refers to cellulose fibers having a fiber diameter of the nano-order or micro-order, prepared through micronization treatment. In this specification, these are referred to as cellulose nanofibers (CNF) and cellulose microfibrils (MFC), respectively.

[0028] The average fiber diameter (length-weighted average fiber diameter) of CNF is 500 nm or less, preferably 300 nm or less, more preferably 100 nm or less, and even more preferably 50 nm or less. The lower limit is not particularly limited, but is usually 1 nm or more, preferably 2 nm or more. Therefore, the average fiber diameter (length-weighted average fiber diameter) of CNF is usually 1 to 500 nm or 2 to 500 nm, preferably 2 to 300 nm or 2 to 100 nm, more preferably 2 to 50 nm or 3 to 30 nm. The average fiber length (length-weighted average fiber length) is usually 50 to 2000 nm, preferably 100 to 1000 nm. The aspect ratio of CNF is usually 10 or more, preferably 50 or more. The upper limit is not particularly limited, but is usually 1000 or less.

[0029] The average fiber diameter of MFCs is usually 500 nm or more, preferably 1 μm or more, and more preferably 3 μm or more. This allows for higher water retention compared to unfibrillated cellulose fibers, and even in small quantities, a high strength-imparting effect and yield improvement effect can be obtained compared to finely fibrillated CNF. The upper limit of the average fiber diameter is preferably 60 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and even more preferably 20 μm or less, but there are no particular restrictions. The average fiber length is usually 10 μm or more, 20 μm or more, or 40 μm or more, preferably 200 μm or more, 300 μm or more, or 400 μm or more. More preferably 500 μm or more or 550 μm or more, and even more preferably 600 μm or more, 700 μm or more, or 800 μm or more. The upper limit is not particularly limited, but is usually 3,000 μm or less, preferably 2,500 μm or less, more preferably 2,000 μm or less, even more preferably 1,500 μm or less, 1,400 μm or less, or 1,300 μm. The aspect ratio of the MFC is preferably 3 or more, more preferably 5 or more, even more preferably 7 or more, and may be 10 or more, 20 or more, or 30 or more. The upper limit of the aspect ratio is not particularly limited, but is preferably 1000 or less, more preferably 100 or less, and even more preferably 80 or less.

[0030] The average fiber diameter and average fiber length of fibrous cellulose can be determined using a fractionator manufactured by Valmet Co., Ltd. When using the fractionator, these can be determined as length-weighted fiber width and length-weighted average fiber length, respectively. The average aspect ratio of fine cellulose fibers can be calculated using the formula: Average aspect ratio = Average fiber length / Average fiber diameter.

[0031] The fibrous cellulose may be either modified or unmodified. Modified fibrous cellulose refers to fine cellulose fibers (e.g., cellulose nanofibers, cellulose microfibrils) in which at least one of the three hydroxyl groups contained in the glucose unit has been chemically modified (hereinafter simply referred to as "modified"). Chemical modification treatment sufficiently refines the cellulose fibers, and defibration yields cellulose nanofibers with a uniform average fiber length and average fiber diameter. Therefore, when compounded with rubber components, it can exhibit a sufficient reinforcing effect. From this viewpoint, modified cellulose fibers are preferred.

[0032] Modifications include, for example, oxidation, etherification, esterification such as phosphate esterification, silane coupling, fluorination, and cationization. Among these, oxidation (carboxylation), etherification, cationization, and esterification are preferred, with oxidation (carboxylation) being more preferred.

[0033] [2. Method for producing cellulose material] The cellulose material is not particularly limited as long as it is obtained from a cellulose raw material by any method. In the case of powdered cellulose, for example, a method including at least a grinding process is possible, and a method including a mechanical grinding process is preferred. In the case of fibrous cellulose, for example, a method including a defibration process is possible.

[0034] [2.1. Cellulose raw materials] Cellulose raw materials are usually naturally derived cellulose, with pulp being preferred and wood-derived pulp being more preferred. Examples of wood-derived pulp include pulp derived from hardwoods and pulp derived from softwoods. Methods for preparing wood-derived pulp include, for example, methods that include bleaching. Examples of bleaching methods include, optionally, chlorine treatment (C), chlorine dioxide bleaching (D), alkaline extraction (E), hypochlorite bleaching (H), hydrogen peroxide bleaching (P), alkaline hydrogen peroxide treatment (Ep), alkaline hydrogen peroxide / oxygen treatment (Eop), ozone treatment (Z), chelation treatment (Q), and combinations of two or more of these treatments applied to pulp that has been deligninized by a conventional method. Examples of combinations (sequences) of two or more processes include DE / PD, C / DEHD, ZED-PZ / D-Ep-D, Z / D-Ep-DP, D-Ep-D, D-Ep-DP, D-Ep-PD, Z-Eop-DD, Z / D-Eop-D, and Z / D-Eop-DED (where " / " in the sequence means that the processes before and after " / " are performed consecutively without washing). The bleaching process is not limited to the examples above and may be any method commonly used. The pulp after bleaching is usually in a fluid state (fluid pulp). The whiteness of the pulp is preferably 80% or higher, based on ISO 2470.

[0035] One example of a pulp preparation method is the pulping method (digestion method). Through pulping, lignin, a coloring substance, is dissolved and removed, resulting in pulp with high whiteness. Examples of pulping methods include sulfite digestion, kraft digestion, soda-quinone digestion, and organosolve digestion, with kraft pulp being preferred from an environmental perspective. Mechanical pulps such as groundwood pulp (GP), refiner groundwood pulp (RGP), thermomechanical pulp (TMP), and chemothermetic pulp (CTMP) can also be used.

[0036] The moisture content of the cellulose raw material is usually preferably 5-30%, and more preferably 6-20%, relative to 100% of the cellulose raw material. If the moisture content of the cellulose raw material is higher than the above range, the moisture content can be adjusted by the dehydration and drying treatment described later.

[0037] [2.2. Method for producing powdered cellulose] [Mechanical grinding process] Grinding is a process of mechanically grinding cellulose raw materials. Prior to grinding, pretreatment such as dehydration and drying or acid hydrolysis may be performed, with dehydration and drying being preferred. Classification may be performed simultaneously with or after grinding.

[0038] Examples of grinders include cutting mills, impact mills, airflow mills, hammer mills, roll mills, roller mills, media mills, media stirring mills, vibratory mills, and freeze grinders. These can be used individually or in combination of two or more types.

[0039] Examples of cutting mills include the Cutting Mill (manufactured by Horai Co., Ltd.), Mesh Mill (manufactured by Horai Co., Ltd.), Atoms (manufactured by Yamamoto Hyakuma Seisakusho Co., Ltd.), Knife Mill (manufactured by Parman Co., Ltd.), Cutter Mill (manufactured by Tokyo Atomizer Manufacturing Co., Ltd.), Sentry Cutter (manufactured by Nippon Coke Industries Co., Ltd.), Rotary Cutter Mill (manufactured by Nara Machinery Manufacturing Co., Ltd.), Turbo Cutter (manufactured by Freund Turbo Co., Ltd.), and Pulp Crusher (manufactured by Zuiko Co., Ltd.).

[0040] Examples of hammer-type mills include the Hammer Mill (manufactured by Hosokawa Micron Corporation), the Jaw Crusher (manufactured by Makino Corporation), and the Hammer Crusher (manufactured by Makino Sangyo Co., Ltd.).

[0041] Examples of impact mills include the Pulverizer (manufactured by Hosokawa Micron Corporation), Fine Impact Mill (manufactured by Hosokawa Micron Corporation), Super Micron Mill (registered trademark, manufactured by Hosokawa Micron Corporation), Inomizer (registered trademark, manufactured by Hosokawa Micron Corporation), Fine Mill (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), CUM type centrifugal mill (manufactured by Mitsui Mining Co., Ltd.), Exceed Mill (manufactured by Makino Sangyo Co., Ltd.), Ultraplex (manufactured by Makino Sangyo Co., Ltd.), Contraplex (manufactured by Makino Sangyo Co., Ltd.), Coroplex (manufactured by Makino Sangyo Co., Ltd.), Atomizer (manufactured by Seishin Corporation), and Tornado Mill (Nikkiso). Examples include: (manufactured by Nara Machine Works Co., Ltd.), Neamill (manufactured by Dalton Co., Ltd.), Free Grinder (manufactured by Nara Machine Works Co., Ltd.), New Cosmomizer (manufactured by Nara Machine Works Co., Ltd.), Turbomill (manufactured by Freund Turbo Co., Ltd.), Super Powder Mill (manufactured by Nishimura Machine Works Co., Ltd.), Blade Mill (manufactured by Nisshin Engineering Co., Ltd.), Super Rotor (manufactured by Nisshin Engineering Co., Ltd.), Wiley Grinder (manufactured by Sanki Seisakusho Co., Ltd.), Pulp Grinder (manufactured by Zuiko Co., Ltd.), Jacobson Fine Grinder (manufactured by Shinko Pantech Co., Ltd.), Universal Mill (manufactured by Tokuju Kogyo Co., Ltd.), and Continuous Vibromill (manufactured by Euras Techno Co., Ltd.).

[0042] Examples of airflow mills include the CGS type jet mill (manufactured by Mitsui Mining Co., Ltd.), MicronJet (registered trademark, manufactured by Hosokawa Micron Corporation), CounterJet Mill (registered trademark, manufactured by Hosokawa Micron Corporation), CrossJet Mill (manufactured by Kurimoto Iron Works Co., Ltd.), Supersonic Jet Mill (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), CurrentJet (manufactured by Nisshin Engineering Co., Ltd.), Jet Mill (manufactured by Sansho Industry Co., Ltd.), Selenium Mirror (manufactured by Masuko Sangyo Co., Ltd.), New Microsictomat (manufactured by Masuno Seisakusho Co., Ltd.), and Cryptron (manufactured by Earth Technica Co., Ltd.).

[0043] Examples of roller mills include vertical roller mills (manufactured by Seishin Co., Ltd.), vertical roller mills (manufactured by Shinion Co., Ltd.), roller mills (manufactured by Kotobuki Giken Kogyo Co., Ltd.), VX mills (manufactured by Kurimoto Iron Works Co., Ltd.), KVM type vertical roller mills (manufactured by Earth Technica Co., Ltd.), and IS mills (manufactured by IHI Plant Engineering Co., Ltd.). An example of a vibratory mill is a batch-type vibratory mill (manufactured by Chuo Kako Co., Ltd.). Of these, cutting mills and roller mills are preferred.

[0044] The grinding conditions can be appropriately set to obtain the desired powdered cellulose. For example, the grinding conditions (e.g., processing time, input amount) can be adjusted by referring to a calibration curve created from the desired physical properties of the powdered cellulose.

[0045] [Neutralization, washing, dehydration, and drying process] When producing powdered cellulose from cellulose raw materials, appropriate pretreatment is performed before the grinding process. Examples of pretreatment include neutralization, washing, dehydration, and drying, with dehydration and drying preferably performed in this order. The solid content of the cellulose raw material can be adjusted by the drying (dehydration) process, making it easy to control the physical properties of the powdered cellulose. The solid content is usually adjusted to 15% or more, preferably 20% or more. Drying is preferably done using an airflow dryer. This allows the cellulose raw material to be dispersed in an airflow while being exposed to high-speed hot air, regardless of whether it is a cake-like solid, slurry, or solution, and the reduced pressure effect inside the dryer can be utilized, allowing for instantaneous drying. In addition, because the exposure time to hot air is extremely short, the product temperature can be kept low, making it ideal for drying heat-sensitive products or products with low melting points. The conditions for drying with an airflow dryer are not particularly limited and can be set as appropriate, but an example is as follows. The outlet drying temperature is typically 80-180°C, preferably 90-160°C. The air supply volume is typically 150-350 m³. 3 / h, preferably 160-320m 3 It is / h. On the other hand, when using a spray dryer, the material is sprayed and instantly dried with hot air to produce granules. Therefore, it is often unsuitable for drying solid or semi-solid objects with low moisture content, and the particles are more easily exposed to high heat instantaneously than when dried with an airflow dryer, raising concerns about the impact on the product.

[0046] [Acid hydrolysis treatment] Examples of acids used in the acid hydrolysis treatment include mineral acids such as hydrochloric acid, sulfuric acid, and nitric acid. The acid concentration is not particularly limited, but from the viewpoint of maintaining the degree of polymerization and whiteness, it is preferable that it be lower than the acid concentration used in the acid hydrolysis treatment of conventional powdered cellulose production, more preferably 0.4 to 2.0 N, and more preferably 0.5 to 1.5 N. If the acid concentration is less than 0.4 N, the depolymerization of cellulose by the acid is suppressed, and the decrease in the degree of polymerization of cellulose can be reduced, but it may become difficult to mill. On the other hand, if it exceeds 2.0 N, the depolymerization of cellulose proceeds and milling becomes easier, so the powder flowability is improved, but the hardness of the tablets may decrease (they may become more prone to crumbling when molded) due to the decrease in the degree of polymerization. The reaction conditions for the acid hydrolysis treatment are not particularly limited, but the reaction temperature is usually 80 to 100°C, and the reaction time is usually 30 minutes to 3 hours.

[0047] Prior to acid hydrolysis, the cellulose raw material may be pretreated. Examples include slurring of the cellulose raw material (preparation of dispersion) and adjustment of the cellulose raw material concentration. The concentration of the cellulose raw material is usually 3 to 10% by weight (on a solid content basis) relative to the dispersion. If the cellulose raw material is a bleached liquid pulp, it is common to increase the pulp concentration before hydrolysis. Dehydrators such as screw presses and belt filters may be used to adjust (concentrate) the cellulose raw material concentration. Acid hydrolysis may be performed on a slurry of the cellulose raw material, or on a sheet of cellulose raw material. If the cellulose raw material is a dry sheet of pulp, the pulp is usually loosened before acid hydrolysis. A crusher such as a roll crusher may be used to loosen the pulp.

[0048] During the pulverization process after acid hydrolysis, at least one other component (e.g., an organic component, an inorganic component) may be added to the pulverized product along with the acid hydrolyzed product, if necessary. This can impart or improve the functionality of the powdered cellulose. The amount of the other component should be appropriately selected. Furthermore, prior to the pulverization process, the acid hydrolyzed product may be subjected to the aforementioned neutralization, washing, dehydration, and drying treatments.

[0049] The cellulose material may be chemically treated as needed. The chemical treatment should preferably be one that does not significantly impair the degree of polymerization of the cellulose raw material. The chemical treatment may be performed during the grinding process of the cellulose raw material, or before the pretreatment for grinding.

[0050] [2.3. Method for producing fibrous cellulose] Fibrous cellulose can be produced by a method including a defibrillation treatment. Defibrillation (fibrillation) is usually obtained by mechanical treatment, and the mechanical treatment is preferably disintegration or beating. The mechanical treatment (preferably beating or disintegration) is usually carried out wet (i.e., in the form of an aqueous dispersion). Examples of equipment used for mechanical processing include refiners (e.g., disc type, conical type, cylinder type), high-speed defibrators, shear-type agitators, colloid mills, high-pressure jet dispersers, beaters, PFI mills, kneaders, dispersers, high-speed defibrators (top finers), high-pressure or ultra-high-pressure homogenizers, grinders (stone mill type grinders), ball mills, vibratory mills, bead mills, single-screw, twin-screw or multi-screw kneaders / extruders, homomixers under high-speed rotation, refiners, defibrators, friction grinders, high-shear defibrators, dispersers, homogenizers (e.g., microfluidizers), and other equipment capable of providing mechanical defibration. Equipment capable of providing defibration in a wet manner is preferred, and high-speed defibrators and refiners are more preferred, but are not particularly limited. The defibration process is usually carried out with the cellulose raw material dispersed in water.

[0051] If the fibrous cellulose is modified fibrous cellulose, a chemical modification treatment is performed before or after (usually before) defibration. Examples of modification treatments include oxidation, etherification, esterification such as phosphate esterification, silane coupling, fluorination, and cationization. Among these, oxidation (carboxylation), etherification (e.g., carboxyalkylation), cationization, and esterification are preferred, with oxidation (carboxylation) and carboxyalkylation being more preferred.

[0052] [3. Uses of Cellulose Materials] Cellulose materials can be used, for example, as industrial additives (for resins such as polypropylene, phenolic resin, and melamine resin, and for various types of rubber), as excipients for tablet and other formulations (food, pharmaceuticals, quasi-drugs, cosmetics), etc. They can also be used as components and raw materials for resin compositions (e.g., polyolefin resins, modified polyolefin resins, rubber), rubber compositions (e.g., automobiles, personal computers, building materials, containers), food additives (e.g., shredded cheese, fried products, breadcrumbs, casings for ham and sausages and their pickling solutions), hygiene products / cosmetics (e.g., facial cleansers, toothpastes, foundations), filtration aids (e.g., rare metals, food-grade materials), paint / adhesive additives (e.g., urethane paints), and animal feed (e.g., pet food, fishing bait). [Examples]

[0053] The present invention will be described below with reference to examples. The following examples are not intended to limit the present invention. The test methods used in the examples of this application are shown below. Unless otherwise specified, the measurement methods for physical properties, etc., are those described above.

[0054] <Measurement of iron content (ppm)> 0.5 g of powdered cellulose was weighed into a microwave decomposition vessel, and 2 ml of pure water and 5 ml of nitric acid were added to prepare the sample. After microwave decomposition of the sample, it was transferred to a polypropylene container. 2 ml of internal standard solution was added to the sample, and the volume was adjusted to 50 ml. The iron content was measured using a triple quadrupole ICP mass spectrometer.

[0055] The measurement conditions for the ICP mass spectrometer are as follows: • Model: Agilent 8800 (manufactured by Agilent Technologies, Inc.) Collision and reaction cell introduction gases: helium and hydrogen • Measurement m / z: Iron; 56 • Internal standard element m / z: Rhodium; 103

[0056] <Ash content (%)> The ash content was measured using the following procedure. 1) 5-8 g of the sample was placed in a porcelain crucible of known weight, and the sample weight was accurately measured. The crucible was preheated (800°C, approximately 1 hour) before adding the sample, and its weight was accurately measured after cooling in a desiccator for 30 minutes. If soda ash melted and accumulated in the crucible, it was washed with hydrochloric acid. 2) After accurate weighing, the crucible containing the sample was heated with an electric heater to carbonize it. Carbonization was continued until no more white smoke was produced. Then, it was placed in an electric furnace adjusted to 800°C and ashed for 2 hours. 3) After incineration, the crucible was removed and placed in a desiccator. 4) After cooling for 30 minutes, the ashing residue was precisely weighed using a precision balance. The ash content was calculated using the following formula, and the result was calculated to three decimal places and reported to two decimal places.

number

[0057] <Particle size distribution, average particle size, span of particle size distribution> A laser diffraction particle size distribution analyzer (Mastersizer 3000, Malvern Panalytic Division, Spectris) was used. The particle size distribution was measured using the laser scattering method, employing dry measurement, wet measurement (with ultrasonic irradiation), and wet measurement (without ultrasonic irradiation). When the particle size distribution was expressed as a volume accumulation distribution, the values ​​corresponding to 10%, 50%, and 90% of the cumulative volume accumulation distribution were defined as particle size distributions D.10, D.50, and D.90, respectively. D.50 for the wet measurement (without ultrasonic irradiation) was defined as the average particle size. Furthermore, the span of the particle size distribution was calculated using the aforementioned equation (1).

[0058] Dry measurements were performed by adding the sample to the supply port so that the scattering intensity was less than 1%, under the following conditions. • Distributed unit: Aero5 • Air pressure: 2 bar • Feed rate: 25

[0059] For wet measurements, the sample was added to the measurement section of water being stirred at 3500 rpm so that the scattering intensity was approximately 10%. When ultrasonic irradiation was used, the sample in the water was exposed to ultrasound before the wet measurement was performed, based on the following conditions. • Mode: Continuous ·Strength: 100% • Time: 600 seconds

[0060] The particle size distribution analysis was performed under the following conditions in all measurement cases. • Analysis: General purpose • Analysis sensitivity: Enhanced • Light scattering model: Mie theory

[0061] <Average fiber length (mm), average fiber width (μm), L / D> Measurements were performed using the L&W Fiber Tester Plus (manufactured by ABB) following these steps: 0.1 g of the sample was placed in a cylinder containing 200 ml of pure water, stirred for about 1 minute, then transferred to a dedicated 300 ml beaker, set in the sample cycler, and measurement was started to measure the average fiber length and average fiber width. The L / D ratio was calculated from the obtained average fiber length and average fiber width.

[0062] <Thermogravimetric residual rate (500℃)%> The thermal weight retention rate was measured using a thermal analyzer. Specifically, powdered cellulose was heated to 600°C (under an oxygen-free, nitrogen atmosphere), its weight at 500°C was read, and the percentage of this weight relative to the weight before heating was calculated as the thermal weight retention rate.

[0063] <Preparation of powdered cellulose> (Example 1) Bleached wood pulp sheets (LBKP dry sheets, manufactured by Nippon Paper Industries Co., Ltd., 20% moisture content) were used as raw materials. They were cut using a cutting mill (PIH3-20210YRFS, manufactured by Horai Co., Ltd., using a 3mm diameter punching plate). The resulting pulverized material was then pulverized using a vertical roller mill (STR-20, manufactured by Seishin Corporation, feed rate 600g / min, grinding rotor 40Hz, classification rotor 50Hz, blower 50Hz). The resulting pulverized material was used as the powdered cellulose of Example 1. Various physical properties are shown in Table 1.

[0064] (Example 2) The procedure was the same as in Example 1, except that a cutting mill (HA8-2542, manufactured by Horai Co., Ltd., main mesh #250, auxiliary mesh #20) was used in the second stage of the pulverizer, and the resulting pulverized material was used as the powdered cellulose of Example 2. Various physical properties are shown in Table 1.

[0065] (Example 3) Wood pulp (thermomechanical pulp, manufactured by Nippon Paper Industries Co., Ltd., 60% moisture content) was dehydrated, loosened, and dried to obtain a raw material (10% moisture content). This material was then pulverized using a cutting mill (HA8-2542, manufactured by Horai Co., Ltd., main mesh #250, auxiliary mesh #50), and the resulting pulverized material was used as the powdered cellulose in Example 3. Various physical properties are shown in Table 1.

[0066] (Comparative Example 1) Commercially available powdered cellulose ST-02 (manufactured by Asahi Kasei Corporation) was used as the powdered cellulose in Comparative Example 1. Various physical properties are shown in Table 1.

[0067] (Comparative Example 2) Bleached wood pulp sheets (NDPT dry sheets, manufactured by Nippon Paper Industries Co., Ltd., 7% moisture content) were used as raw material and crushed in an Oniha crusher (RC-600, manufactured by Makino Sangyo Co., Ltd.) under the following conditions: raw material input amount of 100 kg, feed rate of 5.0 kg / min, and rotation speed of 10 rpm. The resulting pulverized material was then crushed for 30 minutes in a batch-type vibratory mill (MB3 type, manufactured by Chuo Kakoki Co., Ltd.) under the following conditions: raw material input amount of 45 g (0.25 L), vibration frequency of 1000 cpm, amplitude of 8 mm, ball diameter of 30 mm, and ball filling rate of 80%. The resulting pulverized material was used as the powdered cellulose for Comparative Example 2. Various physical properties are shown in Table 1.

[0068] (Comparative Example 3) Except for using bleached wood pulp sheets (LDPT dry sheets, manufactured by Nippon Paper Industries Co., Ltd., moisture content 7%), the same procedure as in Comparative Example 2 was followed, and the resulting pulverized material was used as the powdered cellulose for Comparative Example 3. Various physical properties are shown in Table 1.

[0069] [Table 1]

[0070] Compared to Comparative Examples 1-3, which contained no or trace amounts of iron, Examples 1-3, which had a higher iron content, showed a higher thermal weight retention rate. Furthermore, the thermal weight retention rate of Examples 1-3 was proportional to the ash content. These results indicate that the powdered cellulose of the present invention has a high yield after heat treatment and excellent recyclability.

Claims

1. The amount of iron component detected by a triple quadrupole-inductively coupled plasma mass spectrometer is greater than 10 ppm and less than or equal to 50 ppm, and this is powdered cellulose. The 50% particle size measured under wet measurement conditions (without ultrasonic irradiation) was 30-40 μm. The 50% particle size measured under wet measurement conditions (with ultrasonic irradiation) was 30-40 μm. The 50% particle size measured under dry measurement conditions was 30–52 μm. The 50% particle size measured under wet measurement conditions (without ultrasonic irradiation) is the 50% particle size measured using a laser diffraction particle size distribution analyzer without ultrasonic irradiation after adding water. The 50% particle size measured under wet measurement conditions (with ultrasonic irradiation) is the 50% particle size measured using a laser diffraction particle size distribution analyzer after adding water and performing ultrasonic irradiation. The 50% particle size measured under dry measurement conditions is the 50% particle size measured using a laser diffraction particle size distribution analyzer without the addition of water. Cellulose material.

2. The cellulose material according to claim 1, wherein the amount of ash after heating at 800°C for 2 hours is 0.13% by weight or more relative to 100% by weight of the cellulose material before heating.

3. The cellulose material according to claim 1 or 2, wherein the thermal weight retention rate at 500°C is 10% or more.

4. A cellulose material according to any one of claims 1 to 3, wherein the average fiber width is 10 to 24 μm.

5. An industrial additive comprising the cellulose material according to any one of claims 1 to 4.

6. A resin composition comprising the cellulose material according to any one of claims 1 to 4.

7. A rubber composition comprising the cellulose material according to any one of claims 1 to 4.

8. A molded article comprising the cellulose material according to any one of claims 1 to 4.

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