JP2002194691A - Modified finely fibrillated cellulose, method for producing the same, paper sheet incorporated with modified finely fibrillated cellulose, and coated paper produced by using modified finely fibrillated cellulose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modified finely fibrillated cellulose usable as a clean internal additive for paper, capable of improving the wet paper strength by its addition to a paper basestock without exerting adverse effect on the environmental load and human body and free from the problems of non-uniform coated face, coating streak and defective printability caused by the coating of paper with a coating material added with the internal additive, and a method for producing the fibrillated cellulose, a paper sheet added with the modified finely fibrillated cellulose and a coated paper produced by coating a base paper surface with the modified finely fibrillated cellulose. SOLUTION: This modified finely fibrillated cellulose has a carbonyl content of 0.05-6.5 mmol/g determined in conformity to semicarbazide method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified fine fibrillated cellulose and a method for producing the same, a paper sheet to which the modified fine fibrillated cellulose is added, and a coated paper using the modified fine fibrillated cellulose. More specifically, a modified fine fibrillated cellulose obtained by modifying a fine fibrillated cellulose obtained by refining cellulose fibers, a modified fine fibrillated cellulose obtained by modifying a cellulose fiber and refined, and modified products thereof. Production method for efficiently producing high quality fibrillated cellulose, and increase the paper strength,
Paper sheet made by adding modified fine fibrillated cellulose that can increase the smoothness and air permeability of paper,
And coated paper utilizing the unique properties of modified fine fibrillated cellulose.

[0002]

2. Description of the Related Art In recent years, the technology shift from the environmental load type technology to the environmental protection type has become active. As one of them, attention has been paid to using natural renewable resources such as wood cellulose without using petroleum-derived plastic materials which are limited resources.

[0003] However, methods for imparting functionality such as water resistance to paper include, in part, natural rosin, starch and derivatives thereof,
Except for alginic acid, almost all of them use synthetic polymer internal additives and external additives in many cases. Especially, the wet paper strength agent currently used has an adverse effect on the human body, such as organic chlorine compounds that generate dioxin. There are many formalin derivatives that have the.

[0004] Against this background, there is a strong demand for the development of clean new drugs. As one of the materials, fine fibrillated cellulose is considered, and many proposals have been made on a method for producing fine fibrillated cellulose and its application.

[0005] Fine fibrillated cellulose is different from micronized cellulose obtained by subjecting cellulose fibers to chemical treatment to take out only the crystal part and mechanically pulverizing with a ball mill or the like.
As an application, for example, cellulose fibers such as wood pulp are refined and added to paper stock, or applied to improve tensile strength, air permeability, or smoothness, and the effect of retaining fillers and dyes due to its microstructure. Techniques for improving the adsorptivity of water have been studied.

[0006] Specifically, there has been proposed a technique for enhancing the paper strength of impregnated base paper by utilizing the properties of fine fibrillated cellulose (Japanese Patent Publication No. 62-033360), or a method of suspending fine fibrillated cellulose in water. Utilizing the fact that the suspension has an appropriate viscosity and good dispersibility, this aqueous suspension is applied to the surface of paper to increase the strength of the paper and improve printability. Has been proposed (JP-A-04-194097).

The same applicant as the present invention is disclosed in
Japanese Patent No. 24300 proposes a method for producing dyed paper, in which a dye / pigment carrier in which fine fibrillated cellulose is loaded with a dye / pigment is added to a paper stock prepared mainly from papermaking pulp to make paper.

Further, the same applicant as the present invention is disclosed in
Japanese Patent Publication No. 284090 discloses a fine fibrillated cellulose which solves the problem of non-uniform coating surface and coating streaks and poor printability which occur when conventional fine fibrillated cellulose is added to a paint and applied to paper. ing.

[0009]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a modified fine fibrillated cellulose having improved properties of conventional fine fibrillated cellulose, and to modify the fine fibrillated cellulose. In order to improve that the conventional fine fibrillated cellulose had a low upper limit to the amount added to the stock from the low drainage, it was possible to increase the amount added, thereby improving workability and characteristics. In addition, by making the modified cellulose fiber finer, it is possible to improve the efficiency of the conventional finer treatment, and by adding it to the paper stock, it is possible to improve wet paper strength and to reduce environmental load. It can be used as a clean internal material for paper that does not adversely affect the human body.It also has uneven coating surfaces and streaks that occur when it is added to paint and applied to paper.
Another object of the present invention is to provide a modified fine fibrillated cellulose which has solved poor printability and the like.

[0010] A second object of the present invention is to provide a production method for efficiently producing these modified fine fibrillated cellulose.

A third object of the present invention is to provide a paper sheet to which these modified microfibrillated cellulose are added.

A fourth object of the present invention is to provide a coated paper obtained by applying the above-mentioned modified fine fibrillated cellulose alone or a paint containing the same to a base paper surface.

[0013]

Means for Solving the Problems As a result of diligent studies to solve the above-mentioned problems, the present invention has found that by modifying fine fibrillated cellulose, the problem arises when fine fibrillated cellulose is added to pulp slurry. It has been found that the low drainage is improved and the limit of the amount of addition can be raised, and it is possible to improve the efficiency of the refining treatment by refining the modified cellulose fiber. Modified fine fibrillated cellulose has been found to be a clean internal additive for paper that has no adverse impact on the environment or the human body. Paper sheets with improved wet strength by adding it to paper stock Further, by applying the modified fine fibrillated cellulose on at least one side of the paper, it is possible to produce a coated paper excellent in printability It found such that you can, came to constitute the present invention.

That is, claim 1 of the present invention is that the amount of carbonyl group determined by the semicarbazide method is 0.05 to
It is a modified fine fibrillated cellulose characterized in that the content is 6.5 mmol / g.

The second aspect of the present invention relates to the modified fine fibrillated cellulose according to the first aspect, wherein the second and third carbon atoms of the pyranose ring in the cellulose are treated with periodic acid or periodate. Cleavage between 2nd and 3rd
At least one of the carbinol groups at the position contains dialdehyde cellulose converted to a carbonyl group.

A third aspect of the present invention is the modified fine fibrillated cellulose according to the first or second aspect, wherein the number average fiber length is 0.05 to 0.3 mm.

According to a fourth aspect of the present invention, the modified fine fibrillated cellulose according to the first or second aspect has a number average fiber length of 0.05 to 0.1 mm and an axial ratio of 50 or more. It is characterized by the following.

According to a fifth aspect of the present invention, the cellulose fibers are oxidatively modified using periodic acid or periodate, and then subjected to a fine treatment. Item 5. A method for producing a modified fine fibrillated cellulose according to any one of Items 4.

The sixth aspect of the present invention is characterized in that the cellulose fibers are subjected to a fine treatment, and thereafter, are oxidatively modified using periodic acid or periodate. 5. A method for producing the modified finely fibrillated cellulose according to any one of 4.

According to a seventh aspect of the present invention, in the manufacturing method according to the fifth or sixth aspect, the fine processing method comprises arranging a plurality of abrasive plates made of abrasive grains having a grain size of 16-120. Using an abrasive plate rubbing device, the pulp slurry that has been beaten beforehand or the pulp slurry that has been oxidized and modified with periodic acid or periodate is passed through It is characterized in that

According to an eighth aspect of the present invention, in the manufacturing method according to the fifth or sixth aspect, the product obtained by the manufacturing method according to the seventh aspect is further subjected to ultrafine fibrillation using a high-pressure homogenizer. It is characterized by.

A ninth aspect of the present invention is a paper sheet obtained by adding the modified fine fibrillated cellulose according to any one of the first to fourth aspects to a pulp as an internal additive material and forming the paper sheet. .

A tenth aspect of the present invention is characterized in that the modified fine fibrillated cellulose alone according to any one of the first to fourth aspects, or a paint containing the same, is applied to at least one surface of a base paper. Coated paper.

[0024]

Embodiments of the present invention will be described below in detail. Cellulose fiber used as a raw material of the modified fine fibrillated cellulose of the present invention is not particularly limited. Specifically, for example, ordinary pulp raw materials such as wood can be used, and more specifically, bleached or unbleached sulfite pulp obtained from softwood or hardwood, kraft pulp, groundwood pulp, explosive pulp, dissolved pulp,
Thermomechanical pulp (TMP), Chemical thermomechanical pulp (CTM)
P) or a mixture of two or more types selected from the group consisting of:
Due to the progress of recycled paper technology and the growing use of recycled paper, recycled pulp such as deinked pulp (DIP) may also be used. Also, non-wood fibers such as hemp, cotton (linter), straw, bamboo, kenaf, bacas, shiogusa, esparto, mulberry, mitsumata, ganpi, ramie, etc. may be used. Cellulose is also included in non-wood fibers. In addition, microbial cellulose, baronia cellulose, squirt cellulose, and the like can also be used.

The modified fine fibrillated cellulose of the present invention has a carbonyl group. In claim 1 of the present invention, the range of the amount of the carbonyl group is defined by a value determined by the semicarbazide method. The semicarbazide method, Watanabe et al. Technical Association of Pulp and Paper Industry Magazine Hokkaido University (1956 published, Vol. 10 No. 67, 524) is a quantitative method reported in reforming the carbonyl group of microfibrillated in cellulose That is, an aldehyde group, a carboxyl group, and a ketone group, and particularly, in the present invention, mainly a aldehyde group obtained by converting a carbinol group by periodate oxidation,
A certain amount of semicarbazide hydrochloride having a hydrazino group highly reactive with a carbonyl group is added and reacted, and a certain amount of iodic acid is also added to the remaining semicarbazide.
The iodine produced by the reduction is determined by iodine titration with sodium thiosulfate to determine the amount of carbonyl groups.

In claim 1 of the present invention, the amount of carbonyl groups is indicated in units of mmol / g, which indicates the amount of carbonyl groups contained in 1 g of the modified fine fibrillated cellulose in an absolutely dry state. . The amount of carbonyl groups determined according to the semicarbazide method is 0.05 to 6.5 mm.
Although it is specified in the range of ol / g, this is a range in which the modified fine fibrillated cellulose of the present invention exerts the desired effect of the present invention. When converted in terms of the glucose unit, which is a constitutional unit of cellulose, the molecular weight of the glucose unit is 162.
１．０1.05 mol / glucose unit. The amount of the carbonyl group is preferably 0.5 to 3.0 mmol / g,
If the amount is less than 0.05 mmol / g, little improvement or improvement in physical properties due to the modification is hardly observed. If the amount exceeds 6.5 mmol / g, the modified fine fibrillated cellulose tends to aggregate, which is not preferable.

In the second aspect of the present invention, the method for modifying the modified fine fibrillated cellulose of the present invention is particularly specified to an oxidation reaction treatment with periodic acid or periodate. Oxidation with periodic acid or periodate is conventionally known as a reaction that simultaneously oxidizes two carbinol groups having a 1,2-glycol structure and further cleaves a carbon bond, and converts it into a polyhydric alcohol or saccharide. Applied. In particular, in the reaction with cellulose, it is known as dialdehyde cellulose in which the carbinol groups at the second and third positions of the pyranose ring in cellulose are selectively oxidized.

In addition, the second of the pyranose ring of cellulose
As the oxidizing agent for selectively oxidizing the carbinol groups at the 2nd and 3rd positions, cerium (IV) nitrate, lead tetraacetate, a combination of cobalt (II) acetate and oxygen, a combination of iodine and mercury (II) oxide An oxidizing agent such as a combination of silver nitrate and potassium peroxodisulfate is used, and the reaction is carried out in an organic solvent.

Therefore, in claim 2 of the present invention, for the above-mentioned reasons, periodate and periodate are limited to oxidizing agents which can be oxidized in water and have low toxicity. Examples of the periodate include sodium metaperiodate and potassium metaperiodate,
Sodium periodate, which has a high solubility in water, is preferred.

The oxidation reaction with periodate or periodate easily proceeds in the amorphous region of the cellulose fiber. Therefore, various methods of amorphization, specifically, mercerization with sodium hydroxide, Regeneration treatment with copper ethylenediamine solution, SO ₂ -DEM (diethylamine) -DM
The degree of crystallinity may be partially or wholly reduced by a regeneration amorphization treatment using an SO solution or the like.

Although dialdehyde cellulose has been widely studied, it is rarely used in the papermaking field.
Other than the modified cellulose obtained by sulfonating dialdehyde cellulose in JP-A-7-324221, "Sulfonated Cellulose and Preparation Method", it is hardly found.
However, dialdehyde starch obtained by periodate oxidization of starch is used as an internal paper strength enhancer in JP-A-58-31199, JP-A-61-207454, and JP-A-3-1704.
Although disclosed in Japanese Patent No. 85197, there are problems such as a method for isolating a product and an improvement in yield.

Since starch is water-soluble and is a homogeneous reaction, uniform oxidation proceeds. On the other hand, cellulose is water-insoluble and is considered to be uneven oxidation. However, since cellulose is hydrophilic, the reaction proceeds. On the contrary, since it is insoluble in water, isolation is easy.

Further, since dialdehyde cellulose obtained by periodate oxidation has a highly reactive aldehyde group, some aldehyde groups are intramolecularly or intermolecularly, and the hydroxyl group at the sixth position of the pyranose ring in the cellulose. Is considered to have a hemiacetal structure by reacting with a carboxol group at the 2nd and 3rd position of the pyranose ring in cellulose according to claim 2 of the present invention. Dialdehyde cellulose containing the structure converted to.

As described above, the modification of the modified fine fibrillated cellulose in the present invention means that the carbinol group of the cellulose is converted into a carbonyl group, and in particular, is obtained by the use of periodic acid or periodate. It refers to selectively oxidizing the carbinol groups at the 2nd and 3rd positions of the pyranose ring in cellulose to convert it to dialdehyde cellulose having a cleavage between the 2nd and 3rd carbon atoms.

Regarding the reaction conditions for periodate oxidation, sodium periodate and the like are unstable to light and decompose. Therefore, it is desirable to operate at room temperature or lower in a dark place.

Further, in an alkaline atmosphere, particularly, the main chain is cut off by β-elimination as a characteristic of the carbonyl group-containing cellulose. Therefore, it is desirable to carry out the reaction on a neutral or acidic side if possible. Preferably, p. H. =
It is around 3.0 to 7.0.

The amount of periodic acid or sodium periodate to be added at the time of the reaction increases as the amount added and the oxidation reaction time increases, but the amount of carbonyl groups formed increases. Since the degradation of the fibrillated cellulose and the aggregation reaction in the modified microfibrils occur, the adjustment is made in consideration of the desired physical properties. In terms of the reaction mechanism, an equimolar periodate of glucose per unit of glucose of cellulose fiber or microfibrillated cellulose reacts theoretically, but 1.0 m per unit of glucose.
If more than the ol amount is added, the water dispersibility of the product becomes worse,
It is considered that aggregation between cellulose molecules occurs.

The oxidation reaction time has little effect if the amount of periodate or sodium periodate is small, but the amount of addition is 0.6 mol per glucose unit.
If the amount is 1 or more, the water dispersibility of the reaction product becomes low from about 72 hours of the oxidation reaction time. Desirably, the amount of periodic acid or sodium periodate is 0.05 to 0.6 mol per glucose unit,
The reaction time is suitably about 24 to 65 hours.

In the present invention, two methods for producing the modified fine fibrillated cellulose are described in claims 5 and 6. Claim 5 of the present invention relates to a method of modifying the cellulose fibers by periodate oxidation and then subjecting them to a fine fibrillation treatment. In this case, when the cellulose fibers to be modified are pulp fibers, they are subjected to periodate oxidation. A factor that influences the degree of beating of pulp (freeness). That is, if the degree of beating is low, the surface area of the cellulose fiber is large, and the reaction easily proceeds uniformly. In addition, since the periodate-oxidized cellulose fiber is weakened, the processing time can be shortened in the subsequent fine processing, and the fine processing efficiency is improved.

On the other hand, a sixth aspect of the present invention is a method in which a cellulose fiber is refined and then oxidatively modified by periodate oxidation. In this case, the entire cellulose fiber or Since most of the fibers are microfibrils that have been micronized, the cellulose has a very large surface area and is well compatible with water, so the periodate oxidation reaction is uniform and the reaction efficiency is somewhat higher. Having. Since the modified microfibrillated cellulose has a carbonyl group (aldehyde group) having high charge polarity and reactivity and also having hydrophobicity, the ultrafine structure in the fibril, particularly on the fibril surface, is slightly aggregated and maintained. Hydropower tends to decrease.

For this reason, the conventional fine fibrillated cellulose has a problem that when added to the pulp slurry, the drainage is low and the amount added to the pulp slurry has a low limit, resulting in poor workability. Oxidation has the effect of reducing the water retention of the finely fibrillated cellulose and greatly improving drainage when added to the pulp slurry.

Specifically, when fine fibrillated cellulose having a solid content ratio of 5 to 50% by mass is added to a 250 to 500 ml CSF beaten pulp slurry, the freeness (beating degree) measured by a Canadian standard freeness tester is used. Is 0-200ml
CSF, and when added in an amount of 10% by mass or more, had a problem that practical freeness could not be obtained.

On the other hand, the modified fine fibrillated cellulose of the present invention is mixed with 250 to 500 ml of CSF pulp at a solid content ratio of 5 to 50% by mass to give a freeness of 1%.
It has properties that are between 00 and 400 ml CSF.

Therefore, when the conventional fine fibrillated cellulose is added to the pulp slurry to make paper, there is a lower upper limit of about 10% by mass of the pulp amount. It is possible to mix paper at an arbitrary ratio depending on the type and the degree of beating of the pulp.

Further, when the microfibrillated cellulose is modified, the ultrafine structure involved in the water holding capacity changes, but the fiber length does not change much. Further, since the aldehyde group introduced by periodate oxidation has high cohesion and reactivity, the interaction with pulp in water is high, and there is almost no outflow from the papermaking net during papermaking.

As described above, the fine fibrillated cellulose has high charge polarity, hydrophobicity, and reactivity by selectively oxidizing the carbinol groups at the second and third positions of the pyranose ring in the cellulose. In the case of cellulose fibers that have been converted to carbonyl groups (aldehyde groups) and have been modified, a micronization treatment is subsequently performed. The modified microfibrillated cellulose obtained by any method is added to the pulp slurry. After papermaking and papermaking, strong crosslinks can be formed in the paper by dehydration and heat drying to improve the wet strength.

In particular, the second of the pyranose ring in cellulose is
The modified microfibrillated cellulose of the present invention in which the carbon between the 2-position and the 3-position is cleaved and both or both of the 2-position and the 3-position carbinol groups are converted to a carbonyl group is a rigid cellulose. Because the pyranose ring is open,
It is considered that characteristics such as high charge polarity, hydrophobicity, and reactivity of the carbonyl group are easily developed. In addition, since the modified microfibrillated cellulose of the present invention is a solid, it is easy to wash and water washing is sufficient, it does not use any petroleum-derived materials, and has no adverse effect on the human body such as organochlorine compounds and formalin. The effect is not included, and it can be said that it is a clean internal additive of environmental protection type.

Further, since the fine fibrillated cellulose modified by periodate oxidation is decomposed in an alkaline atmosphere, the paper containing the modified fine fibrillated cellulose of the present invention can be easily disintegrated in alkaline. It is possible, and there is no problem in the used paper recycling process.

Further, by applying conventional fine fibrillated cellulose to paper and penetrating into porous portions between fibers, the strength between fibers, the smoothness, and the printability can be improved.
The modified fine fibrillated cellulose of the present invention can be applied to applications such as improvement in air permeability (barrier properties), and the properties can be further improved.

Next, a method of a cellulose fine treatment for producing the modified fine fibrillated cellulose of the present invention will be described. As the cellulose fine treatment method,
Conventional methods can be applied. For example, Japanese Patent Publication No. 60-1992
Stability is achieved by repeating a process in which a suspension of fibrous cellulose is passed through a small-diameter orifice as described in JP-A No. 1 and a high-speed is applied by a pressure difference to cause a rapid deceleration so as to perform a cutting action. For producing a suspension of fine microfibrous cellulose, and Japanese Patent Application Laid-Open No. 4-82907.
Patent application title: Cellulose fine treatment method by crushing short fibers of natural cellulose fibers in a dry state as in
Further, as disclosed in Japanese Patent Application Laid-Open No. 06-10286, suspension of fibrous cellulose is carried out by a vibrating mill pulverizer using beads or balls of a material such as glass, alumina, zirconia, zircon, steel and titania as a pulverizing medium. A cellulose fine treatment method in which a liquid is subjected to a wet pulverization treatment is exemplified.

As a method for finely treating cellulose which has solved the above-mentioned problems of the conventional method, a method proposed by the same applicant of the present invention in Japanese Patent Application Laid-Open No. Hei 7-310296 can be used. This method uses an abrasive plate rubbing device in which a plurality of abrasive plates made of abrasive grains having a grain size of 16 to 120 are rubbed and arranged, and the pulp slurry that has been beaten in advance is rubbed in the rubbing portion of this device. The number average fiber length of the fibers is 0.05 to 0.
It is characterized in that a fine fibrillated cellulose having a water retention value of 3 mm, a water retention value of 250% or more, and an integrated number of 95% or more of the total number is 0.5 mm or less. According to this method, since the pulp slurry supplied to the abrasive plate rubbing device has been subjected to preliminary beating, even if the solid content concentration is set to a relatively high concentration of about 5 to 6% by mass, an efficient refining treatment can be performed. There is an advantage that it can be performed.

Further, a method described in Japanese Patent Application Laid-Open No. 8-284090 proposed by the same applicant as the present invention can be used. In this proposal, the fine fibrillated cellulose obtained above is further subjected to ultrafine treatment using a high-pressure homogenizer, so that the number average fiber length is 0.05 to 0.1 mm and the water retention value is 350% or more. The present invention describes an ultrafine fibrillated cellulose in which 95% or more of the total number of fibers with respect to the total number of fibers is 0.25 mm or less, and the axial ratio of the fibers is 50 or more, and a method for producing the same. And ultrafine fibrillated cellulose are also included in the expression microfibrillated cellulose).

[0053] The above-mentioned method for making cellulose finer can be applied to the modified fine fibrillated cellulose of the present invention.

The number average fiber length specified in the present invention is K
It shows the value obtained by integrating the total length of the fibers present in a certain pulp suspension and dividing by the number of the fibers among the data measured by a fiber length distribution measuring device (FS-200) manufactured by AJA ANI (Finland). is there. The ratio of the total number is also obtained from the same measuring device. LBKP, NBKP, etc., which are ordinary paper raw materials, have a number-average fiber length of about 0.5 mm and 1.0 mm, respectively, and even a fibrillated fiber generated by refining has a number-average fiber length of , The minimum length is about 0.35 mm. Further, the modified fine fibrillated cellulose produced using an abrasive plate rubbing device has a number average fiber length of 0.05 to 0.3 m.
m. In contrast, those obtained by further micronizing the modified microfibrillated cellulose with a high-pressure homogenizer have a number average fiber length of 0.05 to 0.1 mm,
It is further miniaturized.

The measurement of the fiber axial ratio (fiber length / width) was performed by direct observation with an optical microscope and an electron microscope. The modified ultrafine fibrillated cellulose produced in the present invention (as described above, collectively referred to as the modified microfibrillated cellulose in the present invention) has a fiber width of 1 μm or less and is the smallest. The axial ratio is 50, that is, the axial ratio is 50 or more. The modified ultrafine fibrillated cellulose of the present invention having such an axial ratio can be clearly distinguished from a powdery cellulose having a short axial ratio.

As a method for producing a paper sheet to which the modified fine fibrillated cellulose of the present invention is added, it can be produced by a conventional paper making process. That is, the modified fine fibrillated cellulose is added to the aqueous dispersion slurry of pulp at an arbitrary ratio,
It can be produced through papermaking / papermaking, a pressing step, and a heating and drying step. The basis weight of the paper is not particularly limited, but is 30 to 200 g /
from m ² of paper, believed to be at 600 g / m ² of cardboard. Further, when producing a paper container with paper to which the modified fine fibrillated cellulose of the present invention is added,
Conventionally known methods are possible, for example, an assembling molding method of punching and bonding four corners with a plunger type can-making machine,
A paper container can be manufactured without a post-process by performing pulp molding by a press molding method capable of hot press molding with a dedicated tray molding machine or by a wet pulp molding method.

Next, a method for producing a coated paper utilizing the properties of the modified fine fibrillated cellulose of the present invention will be described. The modified fine fibrillated cellulose of the present invention can be added to a coating material to be applied as it is, or to a coating material to be applied, by a size press device, a gate roll device, a bill blade coating device, etc. The properties of the modified microfibrillated cellulose can be used to improve the smoothness and air permeability, improve the coating properties of the paint, or use it as it is on a machine or by adding it to the coating paint. Properties, especially printability of coated paper obtained by coating on paper.

Examples of application to on-machine paints 1) Addition to surface size paints: styrene resin, styrene / acrylic resin, styrene / maleic resin, alkyl ketene dimer, starch, oxidized starch, hydroxyethylated starch , Carboxymethylated cellulose, carboxymethylated guar gum, phosphorylated guar gum, oxidized guar gum, polyvinyl alcohol, acrylamide, and other known paints containing the modified microfibrillated cellulose in a concentration of 0.1%.
Add 1 to 10% by mass and apply.

2) Addition to paint for lightweight coated paper: 0.1% to 10% by mass of modified fine fibrillated cellulose is added to a well-known paint mainly containing a filler such as clay, calcium carbonate and kaolin and a binder. Add and coat.

Example of application to off-machine paint : Addition to coated paper and art paper paint: Modified fine fibrillated cellulose is added to a well-known paint mainly containing a filler such as clay, calcium carbonate, kaolin and a binder. Usually, 0.1 to 10% by mass is added and applied.

Coating of modified fine fibrillated cellulose alone
The modified fine fibrillated cellulose is coated on a paper sheet in a range of about 5 g / m ² or less per side by the above-mentioned coating method.

[0062]

Next, the present invention will be described more specifically based on examples and comparative examples, but these examples do not limit the present invention.

<Application Example 1> Preparation of beaten pulp The raw material pulp was softened from softwood kraft pulp (NBKP) papermaking raw material in accordance with JIS-P8209 "Method for preparing handmade paper for pulp test", and JIS-P8121 " According to the Canadian standard freeness test method based on "Pulp Freeness Test Method", a pulp slurry having a freeness (beating degree) of 300 ml CSF was prepared with a beater to obtain a pulp slurry having a solid concentration of 1.0%.

<Application Example 2> Preparation of fine fibrillated cellulose In the same manner as in Application Example 1, NBKP was used as a raw material and 3
It was beaten in advance to 00 ml CSF to prepare a pulp slurry having a solid concentration of 5%. This is shown in Fig. 1 to Fig. 3 by an abrasive plate rubbing device (trade name "Super Grindel" manufactured by Masuyuki Sangyo Co., Ltd. Abrasive particle size: No. 46. Number of rotation of rotary abrasive plate: 1800 rpm, abrasive plate clearance: 20 μm, hopper capacity: 30 liters). The treated pulp slurry discharged from the rubbing portion of the abrasive plate was recirculated to a continuous hopper to obtain a fine fibrillated cellulose with a total refining time of 30 minutes.

<Application Example 3> Preparation of fine fibrillated cellulose Application Example 2 was the same as Application Example 1, except that NBKP was used as a raw material and beaten to 100 ml CSF in advance with a beater.
In the same manner as described above, fine fibrillated cellulose was obtained.

<Application Example 4> Preparation of Fine Fibrillated Cellulose The solid suspension concentration of the aqueous suspension of fine fibrillated cellulose prepared in Application Example 2 was adjusted to 3%. Ultra-fine fibrillation by repeating the process of pumping at a pressure of 1500 kg / cm ² to a high-pressure homogenizer (trade name “Nanomizer”, manufactured by Nanomizer Co., Ltd.) equipped with two discs 21 and 22 for ultrafineness 5 times Cellulose was obtained.

<Application Example 5> Commercially available fine fibrillated cellulose Commercially available fine fibrillated cellulose was used.

<Application Example 6> Commercially available micronized cellulose Commercially available micronized cellulose was used.

Table 1 shows the results of measuring the properties of the fine fibrillated cellulose obtained in the above application examples.

[0070]

[Table 1]

The water retention values in Table 1 were evaluated by the following methods.・ Water retention value: It is an index of the degree of swelling, and is measured based on the idea that water taken in and retained in swelling fibers and free water existing in and between fibers can be distinguished by an appropriate centrifugal force. Value. JAPAN TAPPI
No. 26 is a value measured by the method instructed,
A mat of a fixed amount of a sample is previously formed on a prescribed filter, and centrifuged at 3000 G using a centrifugal separator.
It shows the value when the amount of retained water is divided by the amount of absolutely dried pulp after dehydration for minutes.

These were then used to produce modified pulp for comparison and the modified microfibrillated cellulose of the present invention.

Comparative Example 1 Preparation of Modified Pulp 6 L of NBKP (N.V. = 1.0 mass%, beating degree = 300 csf) aqueous dispersion slurry prepared in Application Example 1 above (absolute dry pulp amount = 60 g) About 16 g corresponding to 0.2 mol of sodium periodate per glucose unit (molecular weight = 162) in the pulp.
Oxidation reaction was carried out by stirring with a stirrer. After 48 hours, several ml of ethylene glycol was added to decompose unreacted sodium periodate, and then methanol was added to reprecipitate minute modified pulp. The mixture was filtered through a 300 mesh Teflon (registered trademark) bag, sufficiently washed with water, and then a modified pulp water dispersion slurry of about 1.0% by mass was obtained.

Example 1 Preparation of Modified Microfibrillated Cellulose The microfibrillated cellulose prepared in Application Example 2 (N.
V. = 1.0% by mass) 6 L of aqueous dispersion slurry (absolute dry amount = 6)
0 g), about 16 g corresponding to 0.2 mol amount of sodium periodate per glucose unit (molecular weight = 162) in the pulp was added, and the mixture was stirred with a stirrer in a cool and dark place to perform an oxidation reaction. After that, several ml of ethylene glycol was added to decompose the unreacted sodium periodate, and then methanol was added to reprecipitate the fine modified fine fibrillated cellulose, followed by filtration through a Teflon bag of about 300 mesh, which was sufficient. After washing with water, an aqueous dispersion of the modified fine fibrillated cellulose of the present invention in an amount of about 1.0% by mass was obtained.

Example 2 Preparation of Modified Fine Fibrillated Cellulose Similarly, 6 L of an aqueous dispersion slurry of fine fibrillated cellulose (N.V. = 1.0% by mass) prepared in Application Example 2 (absolute dry amount = 60 g) ), 0.6 g of sodium periodate per glycose unit (molecular weight = 162) in the pulp.
Production Example 2 except that about 48 g corresponding to the mol amount was added.
In the same manner as in the above, an aqueous dispersion of the modified fine fibrillated cellulose of about 1.0% by mass of the present invention was obtained.

Example 3 Preparation of Modified Fine Fibrillated Cellulose Similarly, 6 L of an aqueous dispersion slurry of fine fibrillated cellulose (N.V. = 1.0% by mass) prepared in Application Example 2 (absolute dry amount = 60 g) ), 1.0 g of sodium periodate per glucose unit (molecular weight = 162) in the pulp.
Production Example 2 except that about 80 g corresponding to the mol amount was added.
In the same manner as in the above, an aqueous dispersion of the modified fine fibrillated cellulose of about 1.0% by mass of the present invention was obtained.

Example 4 Preparation of Modified Fine Fibrillated Cellulose 6 L of aqueous dispersion slurry of ultrafine fibrillated cellulose (NV = 1.0% by mass) prepared in Application Example 4 (absolute dry amount = 60 g) In contrast, sodium periodate was added in an amount of 0.2 m per glucose unit (molecular weight = 162) in the pulp.
Approximately 1.0% by mass of the modified ultrafine fibrillated cellulose aqueous dispersion slurry of the present invention was obtained in the same manner as in Production Example 2 except that about 16 g corresponding to the ol amount was added.

Next, the chemical properties of the modified pulp obtained under the same modification conditions (Comparative Example 1) and the modified microfibrillated cellulose of the present invention (Examples 1 and 4) are shown in Table 2.
And compared. In addition, sodium periodate (Na
The consumption of IO ₄ ) was determined by measuring the UV absorbance in the characteristic absorption range of sodium periodate. When determining the consumption amount of sodium periodate, a calibration curve (FIG. 5) prepared in advance (Y = −0.0973 + 0.0
29977X, correlation coefficient R = 0.998). The amount of carbonyl groups in the modified pulp (Comparative Example 1) and the modified fine fibrillated cellulose of the present invention was quantitatively analyzed by a semicarbazide method.

[0079]

[Table 2]

From the above Table 2, the properties of the modified pulp (Comparative Example 1) obtained under the same modifying conditions and the modified fine fibrillated cellulose of the present invention (Examples 1 and 4) are compared. It was found that the modified microfibrillated cellulose according to the present invention had a higher reaction yield than the modified pulp.
It is considered that this is a heterogeneous reaction of cellulose in water, so that fine fibrillated cellulose, which is fine and has a large surface area and is familiar with water, has a higher oxidative modification reaction efficiency. The reaction yield of the modified microfibrillated cellulose of Example 1 was higher than that of Example 4, but this was due to the fact that Example 4 in which ultrafine fibrillated cellulose having a very short fiber length was modified, It is conceivable that outflow to the filtrate occurs during the washing step, and that if the washing step is devised, the reaction yield will be further improved.

Table 3 shows Example 2 having a high periodate oxidation degree.
The chemical properties of the modified microfibrillated cellulose of the present invention of Example 3 were shown.

[0082]

[Table 3]

<Example 5> Next, the modified pulp (Comparative Example 1) subjected to the modification treatment was subjected to the same refinement step as in Application Example 2, and the same refined structure as in Application Example 2, that is, Examination of the time required for the micronization treatment until the average fiber length (0.12 mm) was achieved revealed that the book having the same number average fiber length in 15 minutes, which is about half the time required for the micronization treatment in Application Example 2 The modified fine fibrillated cellulose of the invention was obtained.

Example 6 This time, the modified microfibrillated cellulose obtained in Example 5 was treated in the same micronization step as in Application Example 4 to obtain the same micronized structure as in Application Example 4, that is, After examining the time of the micronizing treatment until the number average fiber length (0.07 mm) is reached, the number of treatments for ultra-micronizing by feeding to a high-pressure homogenizer is repeated three times as compared to five times in Application Example 4. As a result, the modified ultrafine fibrillated cellulose of the present invention having the same number average fiber length and axial ratio could be obtained.

From this, the refinement treatment of the modified pulp is the usual refinement treatment of the pulp (Application Examples 2 and 4).
On the other hand, it was found that the number average fiber length and the axial ratio were the same even though the refining time and the process were about half. Therefore, it was confirmed that the pulp modified by periodate oxidation progressed finely and the processing efficiency was high. This is presumably because the pulp was weakened by the periodate oxidation reforming treatment.

Next, the modified fine fibrillation of the present invention is described.
An example of a paper sheet internally containing cellulose is shown.
Do not limit the invention. <Example 7> The modified fine particle of the present invention prepared in Example 2 was used.
Aqueous dispersion of brillated cellulose (0.6mol modification)
The slurry was prepared by dispersing the aqueous dispersion of NBKP prepared in Application Example 1 above.
Rally (N.V. = 1.0% by mass, degree of beating = 300cs)
f) at a mixing ratio of 17% for the solid content,
A quasi-type handmade square paper machine with a basis weight of about 80 g / m^Two Modified fine
Make paper containing fine fibrillated cellulose
Less (3.43 × 10 ^Five Pa) for 5 minutes, Yankee
Dry by heating with a dryer (surface temperature = about 120 ° C)
An inventive paper sheet was prepared.

<Example 8> The NBK prepared in the application example 1 was the aqueous dispersion slurry of the modified fine fibrillated cellulose (0.6 mol modification treatment) of the present invention prepared in the example 2
The present invention was carried out in the same manner as in Example 7, except that the aqueous dispersion slurry of P (N.V. = 1.0% by mass, degree of beating = 300 csf) was mixed at a mixing ratio of 33% of the solid content. Was produced.

Example 9 The aqueous dispersion slurry of the modified fine fibrillated cellulose (0.6 mol modified treatment) of the present invention prepared in Example 2 was prepared in NBK prepared in Application Example 1 above.
The present invention was carried out in the same manner as in Example 7, except that the aqueous dispersion slurry of P (N.V. = 1.0% by mass, beating degree = 300 csf) was mixed at a solids mixing ratio of 50%. Was produced.

<Comparative Example 2> NB prepared in Application Example 1
A KP water-dispersed slurry (N.V. = 1.0% by mass, beating degree = 300 csf) was directly used to make a paper having a basis weight of about 80 g / m ^{2 using} a standard handmade square paper machine, and a dewatering press ( 3.43 × 10 ⁵ Pa) for 5 minutes, and heat and dry with a Yankee dryer (surface temperature = about 120 ° C.), and NBK
P base paper was produced.

Comparative Example 3 The aqueous dispersion slurry of fine fibrillated cellulose prepared in Application Example 2 was dispersed in the aqueous dispersion slurry of NBKP prepared in Application Example 1 (NV =
A paper sheet containing micronized cellulose was prepared by performing the same procedure as in Comparative Example 2, except that 1.0% by mass and a degree of beating of 300 csf) were mixed at a mixing ratio of 10% of the solid content.

<Comparative Example 4> The aqueous dispersion slurry of fine fibrillated cellulose prepared in Application Example 2 was dispersed in the aqueous dispersion slurry of NBKP prepared in Application Example 1 (NV =
A paper sheet containing micronized cellulose was prepared by performing the same procedure as in Comparative Example 2, except that the mixture was mixed at a mixing ratio of 50% with a solid content of 1.0% by mass and a beating degree of 300 csf).

Next, the handmade paper sheet containing the modified fine fibrillated cellulose of the present invention obtained in the above Examples 7 to 9 and the NBK obtained in Comparative Examples 2 to 4 were prepared.
Table 4 shows the evaluation results of the properties of P base paper and handmade sheets containing ordinary fine fibrillated cellulose. In addition, each handmade paper sheet is JIS-81 before evaluation.
Based on No. 11, humidity control was performed for 24 hours or more in an environment of 25 ° C. and 65% RH, and each property was evaluated by the following methods.

Amount of carbonyl group in paper: Quantitative analysis by semicarbazide method. Water absorption (%): Each handmade sheet was cut into a shape of 50 × 50 mm, immersed in distilled water for 1 hour, and the water absorption (water content) was calculated from the difference between the mass before immersion and the mass after immersion. . Water absorption (%) = (mass difference before and after immersion (g) / mass before immersion (g)) x 100-Dry breaking length, wet breaking length, wet / dry (%): Each handmade sheet Autograph AG (manufactured by Shimadzu Corporation, Shimadzu Autograph AG-
500A) in a dry state (25 ° C.-65% R)
H) and in a wet state (a test piece was immersed in distilled water for 1 hour) to measure the breaking strength to determine the breaking length.
The dry breaking length ((wet / dry) × 100)% was calculated.

[0094]

[Table 4]

From Table 4, it can be seen that the paper sheet to which the modified microfibrillated cellulose of the present invention is added shows that the paper sheet containing the modified microfibrillated cellulose increases as the amount of the modified microfibrillated cellulose increases (Examples 7 to 10).
9) It can be seen that the wet paper strength is improved, the water absorption is reduced, and the water resistance is improved. In comparison, the water resistance of the paper sheets (Comparative Examples 3 and 4) to which unmodified fine fibrillated cellulose was added was low even when the amount of addition was increased. This is thought to be because the modified microfibrillated cellulose of the present invention has a carbonyl group (aldehyde group) having high charge polarity, reactivity, and hydrophobicity, and a cross-linking reaction occurs in paper. Can be

When the freeness of each sample was compared,
The pulp slurry obtained by mixing 50% of ordinary fine fibrillated cellulose (Comparative Example 4) has a very low freeness of 5CSF and is not practical, whereas the modified fine fibrillated cellulose of the present invention has The freeness of a 50% mixture (Example 9) was also greatly improved, and was within the applicable range. From this, by modifying the fine fibrillated cellulose, drainage when added to the pulp slurry is improved, it is possible to solve the problems of the conventional fine fibrillated cellulose that low workability and the upper limit of the addition amount is low. I understand. The modified fine fibrillated cellulose of the present invention enables the amount of addition to the pulp slurry to be increased, thereby improving not only wet paper strength but also air permeability and smoothness.

Further, 1 g of the paper sheet of Examples 7 to 9 was
In accordance with the conditions of recycled alkaline paper, place it in 1.5 L of a 0.5% by mass aqueous solution of sodium hydroxide and use a standard disintegrator to
After disintegration for minutes, all were completely disintegrated.

Next, examples of coated paper using the modified fine fibrillated cellulose of the present invention will be described. <Example 10> A 2% solid content slurry of the modified fine fibrillated cellulose obtained in Example 4 was coated with a wire on the felt (front) surface of NBKP base paper (basis weight 80 g / m ² ) prepared in Comparative Example 2. The coated paper for printing of the present invention was obtained by applying 2.0 g / m ² with a bar.

Example 11 0.3 parts of sodium hexametaphosphate was added as a dispersant to 90 parts of clay and 10 parts of calcium carbonate, and the mixture was uniformly dispersed with an impeller to a solid concentration of 50%. 5 parts of oxidized starch and 12 parts of SB latex were added, and 3 parts of the modified fine fibrillated cellulose obtained in Example 4 were added to obtain a paint having a solid content of 35%. The NBKP base paper of Comparative Example 2 (basis weight 80 g / m ² )
Was coated on the felt (front) surface to obtain a coated paper for printing of the present invention.

Example 12 A coated paper for printing of the present invention was obtained in the same procedure as in Example 11 except that the modified fine fibrillated cellulose obtained in Example 2 was used.

Comparative Example 5 A printing paper for comparison was obtained in the same procedure as in Example 11 except that the modified fine fibrillated cellulose was not added.

Comparative Example 6 A printing coating for comparison was prepared in the same procedure as in Example 11 except that the commercially available micronized cellulose of Application Example 6 was used instead of the modified microfibrillated cellulose. Obtained paper.

The air permeability of the coated paper of Example 10 and the paper sheet produced in Comparative Example 2 were determined according to JIS-P8117.
The smoothness was determined according to JIS-P8119. Table 5 shows the results.

[0104]

[Table 5]

Table 5 shows that the coated paper coated with the modified fine fibrillated cellulose of the present invention has increased air permeability and smoothness. Since the wire (back) surface is not coated, the smoothness is the same value for the coated paper of Example 10 and the paper sheet prepared in Comparative Example 2.

Examples 11 and 12 and Comparative Example 5
(Viscosity, cps, 20 ° C.), streaking during coating, uniformity of coated surface, smoothness of coated surface, and printability (dry down, color development, dot gain)
Table 6 shows the evaluation results. The evaluation of each characteristic was performed by the following methods.

Streaking at the time of coating: At the time of coating, it was visually evaluated whether or not a phenomenon of streaking due to the presence of foreign matter or the like occurred. -Uniformity of coated surface: After coating, it was visually evaluated whether unevenness occurred on the coated surface due to uneven distribution of filler, binder, modified fine fibrillated cellulose and the like. -Smoothness of coated surface: The surface state after coating was evaluated by feeling.

Dry-down: Using a RI printing tester (manufactured by Mei Seisakusho Co., Ltd.) with blue ink (trade name "TK High Plus Indigo M")
Z ", manufactured by Toyo Ink Co., Ltd.) with an ink loading of 1.0 g, and the ink color density of the printed surface immediately after printing and 3
Macbeth densitometer (CRD-914)
Mold, manufactured by Macbeth). Evaluation was made according to the following criterion based on the amount of decrease in color density at this time. ◎: 0.10 or less, ：: 0.11 to 0.20, Δ: 0.
21 to 0.29, x: 0.30 or more.

Coloring property: A blue ink (trade name “TK High Plus Ai MZ”, manufactured by Toyo Ink Co., Ltd.) was printed with an RI printing tester (manufactured by Akira Seisakusho) at an ink filling volume of 1.0 g, and the printed surface thereof was used. Was measured with a Macbeth densitometer (Model CRD-914, manufactured by Macbeth) both immediately after printing and three days after printing. The color density at this time was evaluated according to the following criteria. ◎: 1.60 or more, ：: 1.50 to 1.59, Δ: 1.
40 to 1.49, x: less than 1.40.

Dot gain: One-color printing of black ink (trade name “Graf-G”, manufactured by Dainippon Ink Industries, Ltd.) using an offset printing machine (two-color machine, R202-OB type, manufactured by Roland) The halftone dot change rate of the portion having a dot area ratio of 40% was measured using a Macbeth densitometer (CRD-914 type), and evaluated according to the following criteria. ◎: within 2%, ：: 2 to 3.9%, Δ: 4 to 5.9%,
X: 6% or more.

[0111]

[Table 6]

As shown in Table 6, when the modified fine fibrillated cellulose of the present invention was added to the paint (Example 1)
1 and Example 12), it was confirmed that the addition of 3 parts, which has an effect on printability, etc., made the viscosity of the paint the optimal value for coating, thereby reducing streaking and smoothness during coating. It was found to be improved. On the other hand, when commercially available fine powdered micronized cellulose was added (Comparative Example 6),
The paint viscosity was too high, resulting in poor streaking during coating, poor smoothness, and poor printability. When 3 parts of the commercially available fine fibrillated cellulose of Application Example 5 was added to the coating material, the number average fiber length was longer than that of the modified fine fibrillated cellulose of the present invention. It has become possible. Regarding printability, when the modified fine fibrillated cellulose was used, both when the modified fine fibrillated cellulose was not used (Comparative Example 5) and when a commercially available fine fibrillated cellulose was used (Comparative Example 6) It was confirmed that the dry-down, color developability, dot gain, and the like at the time of printing were improved as compared with.

[0113]

The modified microfibrillated cellulose of the present invention is a modified microfibrillated cellulose obtained by improving the properties of conventional microfibrillated cellulose, and is obtained by modifying various conventional microfibrillated celluloses. By improving the conventional fine fibrillated cellulose, which has a low upper limit to the amount added to the stock due to low drainage, it is possible to increase the amount of addition, thereby improving workability and characteristics. And refinement of the modified cellulose fiber can improve the efficiency of the conventional refinement treatment.It does not contain any organochlorine compounds or formalin derivatives. In the case of papermaking, high reactivity in the modified microfibrillated cellulose,
Aldehyde groups having hydrophobicity are crosslinked in the paper, exhibiting water resistance such as wet paper strength and low water absorption, and can be improved in water resistance with an increase in the content thereof. It has a remarkable effect that an uneven coating surface, coating streaks, poor printability, and the like, which occur when the coating is performed on paper, can be solved.

The production method of the present invention has a remarkable effect that these modified fine fibrillated celluloses can be efficiently produced.

The paper sheet to which the modified microfibrillated cellulose of the present invention is added has a high wet paper strength, low water absorption and excellent water resistance, and an increased content of the modified microfibrillated cellulose. Thus, the water resistance can be further improved, and there is no problem in the waste paper recycling process, and a remarkable effect of a clean paper sheet which does not adversely affect the environmental load and the human body is exhibited.

The coated paper coated with the coating material to which the modified fine fibrillated cellulose of the present invention has been added has a uniform smooth coated surface, has no coating streaks and the like, and has excellent air permeability. It is excellent in printability, and when this coated paper is used for printing, the coating layer is bulky, so that there is a remarkable effect that dry down, color development, dot gain, etc. are improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an abrasive plate rubbing apparatus for performing a miniaturization process according to the present invention.

FIG. 2 is a cross-sectional view of the device of FIG.

FIG. 3 is a plan view showing an example of an abrasive plate used in the apparatus shown in FIG.

FIG. 4 is a conceptual diagram showing an example of a high-pressure homogenizer used for ultra-fine processing according to the present invention.

FIG. 5 is a graph showing a calibration curve for determining consumption of sodium periodate.

[Explanation of symbols]

 1: fixed abrasive plate 2: rotating abrasive plate 3: grinding chamber 4: rubbing section 5: hopper 6: drive motor 7: feed groove 21: front disk 22: rear disk 21a, 21b, 22a, 22b: penetrating Holes 21c, 22c: grooves 23, 24: cylindrical holding member

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D21H 19/42 D21H 19/42 (72) Inventor Ryuyoshi Matsuo 1-5-1, Taito, Taito-ku, Tokyo Letterpress Inside Printing Co., Ltd. (72) Inventor Junichi Kaminaga 1-5-1, Taito, Taito-ku, Tokyo Letterpress Printing Co., Ltd. (72) Inventor Tomoko Kato 1-15-1, Taito, Taito-ku, Tokyo Letterpress printing Inside (72) Inventor Yuji Matsuda 501, Honjuku, Nagaizumi-cho, Sunto-gun, Shizuoka Pref. Term (reference) 4J038 BA031 BA032 BA051 BA121 BA131 BA141 BA231 CC021 CC061 CE021 CG141 CG171 CJ031 HA266 HA526 HA536 MA08 MA10 NA27 PA18 PB02 PC10 4L055 AA02 AC06 AF10 AF44 AG11 AG12 AG27 A G46 AG48 AG63 AG76 AG89 AG94 AG98 AH02 AH37 AJ04 BB01 BB03 BB30 BE08 EA16 EA18 EA27 EA29 FA08 FA13 FA14 FA15 FA30 GA17 GA19

Claims (10)

[Claims] 1. A modified fine fibrillated cellulose having a carbonyl group content of 0.05 to 6.5 mmol / g determined according to the semicarbazide method. 2. The periodontal acid or periodate cleaves between the carbons at the 2nd and 3rd positions of the pyranose ring in cellulose and at least one of the carbinol groups at the 2nd and 3rd positions. 2. The modified fine fibrillated cellulose according to claim 1, wherein the compound contains dialdehyde cellulose converted to a carbonyl group. 3. The modified fine fibrillated cellulose according to claim 1, wherein the number average fiber length is 0.05 to 0.3 mm. 4. The method according to claim 1, wherein the number average fiber length is 0.05 to 0.1 mm and the axial ratio is 50 or more.
Alternatively, the modified fine fibrillated cellulose according to claim 2. 5. The method according to claim 1, wherein the cellulose fibers are oxidatively modified using periodic acid or periodate, and then subjected to a fine treatment. A method for producing the modified microfibrillated cellulose according to the above. 6. The method according to claim 1, wherein the cellulose fibers are refined and then oxidatively modified using periodic acid or periodate. For producing a modified fine fibrillated cellulose. 7. A refining treatment method uses an abrasive plate rubbing device in which a plurality of abrasive plates made of abrasive grains having a grain size of 16 to 120 are rubbed and arranged. Treated pulp slurry, or periodic acid,
6. The method according to claim 5, wherein the pulp slurry is oxidized and modified by using a periodate to pass the pulp slurry to be refined.
Alternatively, the production method according to claim 6. 8. The method according to claim 5, wherein the product obtained by the method according to claim 7 is further subjected to ultrafine fibrillation using a high-pressure homogenizer. 9. A paper sheet prepared by adding the modified fine fibrillated cellulose according to any one of claims 1 to 4 to pulp as an internal additive material. 10. Coated paper, characterized in that the modified fine fibrillated cellulose alone according to any one of claims 1 to 4 or a paint to which the modified fine fibrillated cellulose is added is applied to at least one surface of a base paper.