JP6921597B2 - Gel membrane - Google Patents

Description

The present invention relates to gel membranes.

In recent years, a material using cellulose fiber, which is a biomass that exists in a large amount in nature, has attracted attention. For example, Patent Document 1 discloses a gel-like body using cellulose nanofibers, which has high elasticity and high heat resistance. Since such a gel-like body can be processed into a film shape, it is expected to be used in the field of packaging containers for cosmetics and foods.

Japanese Unexamined Patent Publication No. 2013-082796

As a membrane used in the field of packaging containers and the like, there is a high need for a membrane (antifouling membrane) that can prevent the adhesion of stains or easily remove the adhered stains.

The present invention relates to a gel film that exhibits an excellent antifouling effect against stains. Furthermore, the present invention relates to a dispersion for a gel film.

The present invention relates to the following [1] to [2].
[1] A gel film having a cellulose fiber composite in which a modifying group is bonded to a carboxy group of a cellulose fiber having a carboxy group content of 0.1 mmol / g or more and an organic medium.
[2] A dispersion for a gel membrane having a cellulose fiber composite in which a modifying group is bonded to a carboxy group of a cellulose fiber having a carboxy group content of 0.1 mmol / g or more and an organic medium.

The gel film of the present invention can exert an excellent antifouling effect against dirt.

[Gel film]
The gel membrane of the present invention has a cellulose fiber complex having a specific structure and an organic medium. Here, the gel film means a film that retains its shape without flowing at room temperature. As the gel film, for example, a film having a Martens hardness (HM) of 0.1 (N / mm ² ) or more calculated by the following formula when measured with a micro hardness tester is preferable. Specifically, the Martens hardness of the gel film is measured by the method described in Examples described later.
HM = F / (26.43 x hmax ² )
F: Test force (N)
hmax: Maximum push-in depth (mm)

The mechanism by which the gel film of the present invention exhibits excellent antifouling property against dirt is not clear, but it is presumed as follows. In the cellulose fiber composite of the present invention, a highly hydrophobic modifying group such as a hydrocarbon compound having an amino group and / or a hydrocarbon group derived from an amino-modified silicone and / or a silicone group is bonded to the carboxy group of the cellulose fiber. Since it has a unique structure of a hydrocarbon, the affinity between the modifying group and the organic medium is enhanced, so that the organic medium is not easily separated from the cellulose fiber composite, and as a result, antifouling property is exhibited. It is presumed that the structure of the cellulose fiber composite can be maintained firmly.

The ratio of the cellulose fibers to the organic medium (cellulose fibers: organic medium) in the cellulose fiber composite in the gel film of the present invention is preferably 1: 0.1 or more as a mass ratio from the viewpoint of antifouling property, more preferably. Is 1: 1 or more, more preferably 1: 3 or more, preferably 1: 100 or less, more preferably 1:80 or less, still more preferably 1:50 or less, still more preferably 1:25 from the viewpoint of durability. It is as follows.

The arithmetic mean roughness of the gel film of the present invention is not particularly limited, and from the viewpoint of antifouling property, the thickness of the gel film is preferably 1 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, and is economical. From the viewpoint of properties, it is preferably 2000 μm or less, more preferably 1200 μm or less, still more preferably 500 μm or less, still more preferably 100 μm or less.

Applications of the gel film of the present invention include, for example, an antifouling film for packaging containers for cosmetics and foods, transportation pipes, ship bottoms, electric wires, and the like.

<Cellulose fiber complex>
The cellulose fiber complex in the present invention is formed by bonding a modifying group to the carboxy group of the cellulose fiber, and may be any one that exhibits dispersibility in an organic medium. Dispersibility in an organic medium means, for example, that the viscosity of a mixture of oil and a target cellulose fiber composite is measured with an E-type viscometer (25 ° C, 1 rpm, 1 minute later, standard cone rotor, rotor cord: When measured using 01), it means that thickening is observed. For example, as the cellulose fiber composite in the present invention, as a typical example of an organic medium, a liquid prepared so that the concentration of cellulose fibers in squalane is 0.5% by mass has a viscosity of 50 mPa. Those having s or more are preferable. The miniaturization process can be performed by the method described later.

The content of the cellulose fiber composite in the gel film of the present invention is preferably 2% by mass or more, more preferably 3% by mass or more, still more preferably 4% by mass or more, from the viewpoint of antifouling property and film durability. be. From the same viewpoint, it is preferably 10% by mass or less, more preferably 8% by mass or less, and further preferably 5% by mass or less.

(Cellulose fiber)
The cellulose fiber as the raw material of the cellulosic fiber composite is preferably a natural cellulose fiber from the environmental point of view. For example, wood pulp such as coniferous pulp and broadleaf pulp; cotton pulp such as cotton linter and cotton lint; straw. Non-wood pulp such as pulp and bagas pulp; bacterial cellulose and the like can be mentioned, and one of these can be used alone or in combination of two or more.
Further, the cellulose fiber is preferably a cellulose fiber having a carboxy group (hereinafter, also referred to as an oxidized cellulose fiber) from the viewpoint of antifouling property, and can be obtained by oxidizing the cellulose fiber.

(Oxidized cellulose fiber)
As the cellulose oxide fiber, for example, 2,2,6,6, -tetramethyl-1-piperidin-N-oxyl (TEMPO) is used as a catalyst, and an oxidizing agent such as sodium hypochlorite, sodium bromide and the like are further used. A method of oxidizing in combination with the bromide of is applicable. More specifically, the method described in JP-A-2011-140632 can be referred to, and further, it can be prepared as an oxidized cellulose fiber from which aldehyde has been removed by performing an additional oxidation treatment or a reduction treatment.

By oxidizing the cellulose fiber using TEMPO as a catalyst, the group at the C6 position (-CH ₂ OH) of the cellulose constituent unit is selectively converted into a carboxy group. Therefore, a preferred embodiment of the oxidized cellulose fiber in the present invention is a cellulose fiber having a carboxy group at the C6 position of the cellulose constituent unit.

(Carboxy group content)
The cellulose fibers constituting the cellulose fiber composite used in the present invention have a carboxy group content of 0.1 mmol / g or more, preferably 0.4 mmol / g or more, more preferably 0. It is 6 mmol / g or more, more preferably 0.8 mmol / g or more. Further, from the viewpoint of improving handleability, it is preferably 3 mmol / g or less, more preferably 2 mmol / g or less, and further preferably 1.8 mmol / g or less. The "carboxy group content" means the total amount of carboxy groups in the cellulose constituting the cellulose fiber, and is specifically measured by the method described in Examples described later.

Further, the preferable ranges of the average fiber diameter, the average fiber length and the average aspect ratio of the cellulose fibers are the same as those of the cellulose fiber composite described later, and can be determined by the same measuring method as the cellulose fiber composite described later. can.

(Modifying group)
As used herein, the binding of the modifying group in the cellulose fiber composite means a state in which the modifying group is ionic and / or covalently bonded to the carboxy group on the surface of the cellulose fiber. Examples of the bonding mode to the carboxy group include an ionic bond and a covalent bond. Examples of the covalent bond here include an amide bond, an ester bond, and a urethane bond, and among them, an amide bond is preferable from the viewpoint of antifouling property. From the viewpoint of antifouling property, the cellulose fiber composite in the present invention is obtained by ionic bonding and / or amide bonding a compound for introducing a modifying group to a carboxy group already existing on the surface of the cellulose fiber. Is preferable.

(Compound for introducing a modifying group)
As the compound for introducing the modifying group, any compound into which the modifying group described later can be introduced may be used, and for example, the following compounds can be used depending on the bonding mode. In the case of an ionic bond, any of a primary amine, a secondary amine, a tertiary amine, a quaternary ammonium compound, and a phosphonium compound may be used. Among these, from the viewpoint of dispersibility, a primary amine, a secondary amine, a tertiary amine, and a quaternary ammonium compound are preferable. Further, as the anion component of the ammonium compound or the phosphonium compound, from the viewpoint of reactivity, halogen ions such as chlorine ion and bromine ion, hydrogen sulfate ion, perchlorate ion, tetrafluoroborate ion and hexa are preferable. Fluorophosphate ion, trifluoromethanesulfonic acid ion, hydroxy ion can be mentioned, and more preferably, hydroxy ion can be mentioned. In the case of covalent bonds, the following can be used depending on the functional group to be substituted.

In the modification to the carboxy group, in the case of an amide bond, one or more selected from the group consisting of a hydrocarbon compound having an amino group such as a primary amine and a secondary amine and an amino-modified silicone compound is preferable. In the case of ester bonds, alcohols are good, and examples include butanol, octanol, and dodecanol. In the case of urethane bond, an isocyanate compound is preferable.

Hydrocarbon compounds having an amino group, amino-modified silicones, phosphonium compounds, acid anhydrides, and isocyanate compounds can be prepared by using commercially available products or by a known method.

As a specific example, examples of the primary to tertiary amines include ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, butylamine, dibutylamine, hexylamine, dihexylamine, octylamine, dioctylamine, trioctylamine, and the like. Examples thereof include dodecylamine, didodecylamine, stearylamine, distearylamine, oleylamine, monoethanolamine, diethanolamine, triethanolamine, aniline and benzylamine. Examples of the quaternary ammonium compound include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetraethylammonium chloride, tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), and tetra. Examples thereof include butylammonium chloride, lauryltrimethylammonium chloride, dilauryldimethylchloride, stearyltrimethylammonium chloride, distearyldimethylammonium chloride, cetyltrimethylammonium chloride, and alkylbenzyldimethylammonium chloride. Among these, from the viewpoint of dispersibility and heat resistance, propylamine, dipropylamine, butylamine, dibutylamine, hexylamine, dihexylamine, octylamine, dioctylamine, trioctylamine, dodecylamine, and didodecyl are preferable. Amines, distearylamines, oleylamines, tetraethylammonium hydroxides (TEAH), tetrabutylammonium hydroxides (TBAH), tetrapropylammonium hydroxides (TPAH), aniline, more preferably propylamines, dodecylamines, oleylamines, tetrabutylammines. Hydroxide (TBAH), aniline.

(Amino-modified silicone compound)
As the amino-modified silicone compound, an amino-modified silicone compound having a kinematic viscosity at 25 ° C. of 10 to 20,000 mm ² / s and an amino equivalent of 400 to 8,000 g / mol is preferable.

The kinematic viscosity at 25 ° C. can be determined by an Ostwald type viscometer, and from the viewpoint of antifouling property, it is more preferably 200 to 10,000 mm ² / s, and further preferably 500 to 5,000 mm ² / s.

The amino equivalent is preferably 400 to 8,000 g / mol, more preferably 600 to 5,000 g / mol, and even more preferably 800 to 3,000 g / mol from the viewpoint of antifouling property. The amino equivalent is the molecular weight per nitrogen atom, and is calculated by amino equivalent (g / mol) = mass average molecular weight / number of nitrogen atoms per molecule. Here, the mass average molecular weight is a value obtained by gel permeation chromatography using polystyrene as a standard substance, and the number of nitrogen atoms can be obtained by an elemental analysis method.

Specific examples of the amino-modified silicone compound include a compound represented by the general formula (a1).

[In the formula, R ^1a represents a group selected from an alkyl group having 1 to 3 carbon atoms, a hydroxy group, an alkoxy group having 1 to 3 carbon atoms, or a hydrogen atom, and is preferably a methyl group or a hydroxy group from the viewpoint of antifouling property. It is a group. R ^2a is a group selected from an alkyl group having 1 to 3 carbon atoms, a hydroxy group or a hydrogen atom, and is preferably a methyl group or a hydroxy group from the viewpoint of antifouling property. B represents a side chain having at least one amino group, and R ^3a represents an alkyl group having 1 to 3 carbon atoms or a hydrogen atom. x and y indicate the average degree of polymerization, respectively, and are selected so that the kinematic viscosity and amino equivalent of the compound at 25 ° C. are within the above ranges. R ^1a , R ^2a , and R ^3a may be the same or different, and a plurality of R ^2a may be the same or different. ]

In the compound of the general formula (a1), from the viewpoint of antifouling property, x is preferably a number of 10 to 10,000, more preferably a number of 20 to 5,000, and further preferably a number of 30 to 3,000. be. y is preferably a number of 1 to 1,000, more preferably a number of 1 to 500, and even more preferably a number of 1 to 200. The mass average molecular weight of the compound of the general formula (a1) is preferably 2,000 to 1,000,000, more preferably 5,000 to 100,000, and even more preferably 8,000 to 50,000.

In the general formula (a1), examples of the side chain B having an amino group include the following.
-C ₃ H ₆ -NH ₂
-C ₃ H ₆ -NH-C ₂ H _4- NH ₂
-C ₃ H ₆ -NH- [C ₂ H _4- NH] _e- C ₂ H _4- NH ₂
-C ₃ H ₆ -NH (CH ₃ )
-C ₃ H ₆ -NH-C ₂ H _4- NH (CH ₃ )
−C ₃ H ₆ −NH − [C ₂ H ₄ −NH] _{f −} C ₂ H ₄ −NH (CH ₃ )
−C ₃ H ₆ −N (CH ₃ ) ₂
-C ₃ H _6- N (CH ₃ ) -C ₂ H _4- N (CH ₃ ) ₂
−C ₃ H ₆ −N (CH ₃ ) − [C ₂ H ₄ −N (CH ₃ )] _g −C ₂ H ₄ −N (CH ₃ ) ₂
-C ₃ H ₆ -NH-cyclo-C ₅ H ₁₁
(Here, e, f, and g are numbers 1 to 30, respectively.)

The amino-modified silicone compound used in the present invention is, for example, sodium hydroxide obtained by hydrolyzing an organoalkoxysilane represented by the general formula (a2) with excess water and dimethylcyclopolysiloxane. It can be produced by heating to 80 to 110 ° C. for an equilibrium reaction using a basic catalyst such as, and neutralizing the basic catalyst with an acid when the reaction mixture reaches a desired viscosity. It can be done (see Japanese Patent Application Laid-Open No. 53-98499).
H ₂ N (CH ₂ ) ₂ NH (CH ₂ ) ₃ Si (CH ₃ ) (OCH ₃ ) ₂ (a2)

The amino-modified silicone compound is preferably a monoamino-modified silicone having one amino group in one side chain B and two amino groups in one side chain B from the viewpoint of antifouling property. at least one element selected from the group consisting of diamino-modified silicone having pieces and more preferably a compound in which the side chain B is represented by -C ₃ H ₆ -NH ₂ with an amino group [hereinafter, (a1-1) component ] And a compound whose side chain B having an amino group is _{represented by -C 3} H _6- NH-C ₂ H _4- NH ₂ [hereinafter referred to as (a1-2) component]. That is all.

As the amino-modified silicone compound in the present invention, from the viewpoint of performance, TSF4703 (kinematic viscosity: 1000, amino equivalent: 1600), TSF4708 (kinematic viscosity: 1000, amino equivalent: 2800) manufactured by Momentive Performance Materials Co., Ltd., SS-3551 (kinematic viscosity: 1000, amino equivalent: 1600), SF8457C (kinematic viscosity: 1200, amino equivalent: 1800), SF8417 (kinematic viscosity: 1200, amino equivalent: 1700) manufactured by Toray Dow Corning Silicone Co., Ltd. ), BY16-209 (kinematic viscosity: 500, amino equivalent: 1800), BY16-892 (kinematic viscosity: 1500, amino equivalent: 2000), BY16-898 (kinematic viscosity: 2000, amino equivalent: 2900), FZ-3760. (Dynamic Viscosity: 220, Amino Equivalent: 1600), KF8002 (Dynamic Viscosity: 1100, Amino Equivalent: 1700), KF867 (Dynamic Viscosity: 1300, Amino Equivalent: 1700), KF-864 (Dynamic Viscosity: 1300, Amino Equivalent: 1700) The kinematic viscosity: 1700, amino equivalent: 3800), BY16-213 (kinematic viscosity: 55, amino equivalent: 2700), BY16-853U (kinematic viscosity: 14, amino equivalent: 450) are preferable. In (), the kinematic viscosity shows a measured value (unit: mm ² / s) at 25 ° C., and the unit of amino equivalent is g / mol.

As the component (a1-1), BY16-213 (kinematic viscosity: 55, amino equivalent: 2700) and BY16-853U (kinematic viscosity: 14, amino equivalent: 450) are more preferable.
The components (a1-2) include SF8417 (kinematic viscosity: 1200, amino equivalent: 1700), BY16-209 (kinematic viscosity: 500, amino equivalent: 1800), FZ-3760 (kinematic viscosity: 220, amino equivalent: 1600). ) Is more preferable.

The average bond amount of one or more groups selected from the group consisting of modifying groups, preferably hydrocarbon groups and silicone groups in the cellulose fiber composite is preferably 0 from the viewpoint of the mechanical strength of the obtained gel film. It is 0.01 mmol / g or more, more preferably 0.05 mmol / g or more, still more preferably 0.1 mmol / g or more, still more preferably 0.3 mmol / g or more, still more preferably 0.5 mmol / g or more. From the viewpoint of reactivity, it is preferably 3 mmol / g or less, more preferably 2.5 mmol / g or less, still more preferably 2 mmol / g or less, still more preferably 1.8 mmol / g or less, still more preferably 1.5 mmol / g. It is less than or equal to g. Here, even when the hydrocarbon group and the silicone group are introduced at the same time, it is preferable that the individual average bond amount is within the above range.

The introduction rate of the hydrocarbon group or the silicone group is preferably 10% or more, more preferably 30% or more, still more preferably 50%, for any of the modifying groups, from the viewpoint of the mechanical strength of the obtained gel film. Above, more preferably 60% or more, further preferably 70% or more, and from the viewpoint of reactivity, preferably 99% or less, more preferably 97% or less, still more preferably 95% or less, still more preferably 90% or less. Is. Here, when the hydrocarbon group and the silicone group are introduced at the same time, it is preferable that the total introduction rate is within the above range within a range not exceeding 100% of the upper limit.

The modifying group may have a substituent. For example, in the case of a hydrocarbon group, it is preferable that the total number of carbon atoms of the entire modifying group including the substituent is within the above range. Examples of the substituent include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, an isopentyloxy group, a hexyloxy group and the like. An alkoxy group having 1 to 6 carbon atoms; a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, a butoxycarbonyl group, an isobutoxycarbonyl group, a sec-butoxycarbonyl group, a tert-butoxycarbonyl group, a pentyloxycarbonyl group. An alkoxy-carbonyl group having 1 to 6 carbon atoms in an alkoxy group such as a group or isopentyloxycarbonyl group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom; a 1 carbon atom such as an acetyl group or a propionyl group. Examples thereof include an acyl group of ~ 6; an aralkyl group; an aralkyloxy group; an alkylamino group having 1 to 6 carbon atoms; and a dialkylamino group having 1 to 6 carbon atoms in the alkyl group. The above-mentioned hydrocarbon group itself may be bonded as a substituent.

In the present specification, the average bond amount of the modifying group shall be adjusted according to the amount of the compound added for introducing the modifying group, the type of the compound for introducing the modifying group, the reaction temperature, the reaction time, the solvent and the like. Can be done. The average bond amount (mmol / g) and introduction rate (%) of the modifying group in the cellulose fiber composite are the amount and the ratio of the modifying group introduced into the carboxy group on the surface of the cellulose fiber, and are the cellulose fibers. The carboxy group content of the above can be calculated by measuring according to a known method (for example, titration, IR measurement, etc.).

[Manufacturing method of cellulose fiber complex]
The cellulose fiber used in the present invention can be produced according to a known method without particular limitation as long as a modifying group can be introduced into the above-mentioned cellulose fiber. The cellulose fiber referred to here is an aldehyde by referring to a known method, for example, the method described in JP2011-140632A, and further performing the above-mentioned additional oxidation treatment or reduction treatment as necessary. Can be prepared as an oxidized cellulose fiber from which

Specific production methods include the following two modes depending on the mode in which the modifying group is introduced into the cellulose fiber. That is, an embodiment in which the modifying group is bound to the cellulose fiber by an ionic bond (aspect A) and an embodiment in which the modifying group is bound to the cellulose fiber by a covalent bond (aspect B) can be mentioned. The case of an amide bond as a covalent bond is shown below.
[Aspect A]
Step (1): Natural cellulose fiber is oxidized in the presence of an N-oxyl compound to obtain an oxidized cellulose fiber Step (2A): To introduce the oxidized cellulose fiber obtained in the step (1) and a modifying group. Step of mixing with the compound of [Aspect B]
Step (1): Natural cellulose fiber is oxidized in the presence of an N-oxyl compound to obtain an oxidized cellulose fiber Step (2B): To introduce the oxidized cellulose fiber obtained in the step (1) and a modifying group. Step of amidating with the compound of

As the method for introducing the modifying group, for example, Aspect A can be carried out by referring to the method described in JP-A-2015-143336, and Aspect B can be carried out by referring to the method described in JP-A-2015-143337. Further, in the present invention, a method (first production form) in which a micronization step described later is performed after the step (1) to obtain fine cellulose fibers and then a step (2A or 2B) is performed, and a step (1). A method (second production form) may be carried out in which the steps (2A or 2B) are carried out in order from the first, and then the micronization step is carried out to obtain fine cellulose fibers. The cellulose fiber after the micronization treatment may be particularly referred to as "fine cellulose fiber".

Hereinafter, a method for producing fine cellulose fibers will be described based on the first production form of Aspect A.

[Step (1)]
Step (1) is a step of oxidizing natural cellulose fibers in the presence of an N-oxyl compound to obtain oxidized cellulose fibers. Specifically, the oxidation treatment step (for example, 2,2,6,6-tetramethylpiperidine-1-oxyl) described in JP-A-2015-143336 or JP-A-2015-143337 for natural cellulose fibers. (Oxidation treatment using (TEMPO)) and purification step (if necessary), the carboxy group content is 0.1 mmol / g or more, preferably 0.4 mmol / g or more, more preferably 0.6 mmol / g. As described above, an oxidized cellulose fiber of 0.8 mmol / g or more, preferably 3 mmol / g or less, more preferably 2 mmol / g or less, still more preferably 1.8 mmol / g or less can be obtained. The carboxy group content of the oxidized cellulose fiber can be determined by the same measuring method as that of the cellulose fiber complex described later.

(Miniaturization process)
Next, after the purification step (which may be performed if necessary), a step of refining the cellulose oxide fiber obtained in the step (1) is performed to obtain fine cellulose oxide fibers. In the miniaturization step, it is preferable to disperse the oxidized cellulose fibers that have undergone the purification step in a solvent and perform the miniaturization treatment.

In addition to water, the solvent as the dispersion medium is an alcohol having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms such as methanol, ethanol and propanol; and a ketone having 3 to 6 carbon atoms such as acetone, methyl ethyl ketone and methyl isobutyl ketone. Linear or branched saturated or unsaturated hydrocarbons with 1 to 6 carbon atoms; aromatic hydrocarbons such as benzene and toluene; halogenated hydrocarbons such as methylene chloride and chloroform; lower grades with 2 to 5 carbon atoms Alkyl ethers; polar solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, diesters of succinic acid and triethylene glycol monomethyl ether, and the like are exemplified. These can be used alone or in combination of two or more, but from the viewpoint of operability of the micronization treatment, water, an alcohol having 1 to 6 carbon atoms, a ketone having 3 to 6 carbon atoms, and 2 carbon atoms. Polar solvents such as lower alkyl ethers of ~ 5, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, methyl triglycoldiester succinate and the like are preferable, and water is more preferable from the viewpoint of reducing the environmental load. The amount of the solvent used may be an effective amount capable of dispersing the oxidized cellulose fibers and is not particularly limited, but is preferably 1 to 500 times by mass, more preferably 2 to 200 times by mass with respect to the oxidized cellulose fibers. Is more preferable.

A known disperser is preferably used as an apparatus used in the miniaturization process. For example, a breaker, a beater, a low-pressure homogenizer, a high-pressure homogenizer, a grinder, a cutter mill, a ball mill, a jet mill, a short-screw extruder, a twin-screw extruder, an ultrasonic stirrer, a household juicer mixer and the like can be used. Further, the solid content concentration of the reactant fibers in the micronization treatment is preferably 50% by mass or less.

Thus, the hydroxyl group at the C6 position of the cellulose fiber constituent unit is selectively oxidized to a carboxy group via an aldehyde group, and a cellulose fiber composed of cellulose having a carboxy group content of 0.1 mmol / g or more can be obtained. ..

[Step (2A)]
In the first production form, the step (2A) is a step of mixing the oxidized cellulose fiber obtained through the above step with a compound for introducing a modifying group to obtain a cellulose fiber. Specifically, the oxidized cellulose fiber and the compound for introducing a modifying group may be mixed in a solvent, and can be produced, for example, according to the method described in JP-A-2015-143336.

Examples of the compound for introducing a modifying group used in the step (2A) include the above-mentioned compounds.

The amount of the compound used can be determined by the desired amount of the modifying group bonded to the cellulose fiber, but from the viewpoint of reactivity, the amine group is preferably 0 with respect to 1 mol of the carboxy group contained in the oxidized cellulose fiber. It is 0.01 mol or more, more preferably 0.1 mol or more, and from the viewpoint of product purity, it is preferably 50 mol or less, more preferably 20 mol or less, still more preferably 10 mol or less. The amount of the compound included in the above range may be subjected to the reaction at one time, or may be divided and subjected to the reaction. When the compound is a monoamine, the above amine groups and amines are the same.

As the solvent, it is preferable to select a solvent in which the compound to be used dissolves, for example, methanol, ethanol, isopropyl alcohol (IPA), N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N, N-dimethyl. Acetamide, tetrahydrofuran (THF), diester of succinic acid and triethylene glycol monomethyl ether, acetone, methyl ethyl ketone (MEK), acetonitrile, dichloromethane, chloroform, toluene, acetic acid, water and the like, and one of them alone or Two or more types can be used in combination. Among these polar solvents, a diester of succinic acid and triethylene glycol monomethyl ether, ethanol, DMF, and water are preferable.

The temperature at the time of mixing is preferably 0 ° C. or higher, more preferably 5 ° C. or higher, still more preferably 10 ° C. or higher, from the viewpoint of compound reactivity. Further, from the viewpoint of product quality such as coloring, it is preferably 50 ° C. or lower, more preferably 40 ° C. or lower, and further preferably 30 ° C. or lower. The mixing time can be appropriately set according to the type of compound and solvent used, but from the viewpoint of compound reactivity, it is preferably 0.01 hours or more, more preferably 0.1 hours or more, still more preferably 1 It is more than an hour, preferably 48 hours or less, and more preferably 24 hours or less from the viewpoint of productivity.

After the salt formation, post-treatment may be appropriately performed in order to remove unreacted compounds and the like. As the post-treatment method, for example, filtration, centrifugation, dialysis and the like can be used.

Further, regarding the manufacturing method of the first aspect B, since the step (1) can be performed in the same manner as the aspect A, the step (2B) in the first manufacturing embodiment will be described below. Further, for example, it can be produced by the method described in JP2013-151661A.

[Step (2B)]
In the first production form, the step (2B) is a step of amidating the oxidized cellulose fiber obtained through the above step with a compound for introducing a modifying group to obtain a cellulose fiber. As the mixing method, there is no particular problem as long as the raw materials react with each other. Specifically, the raw materials are mixed in the presence of a condensing agent, and the carboxy group contained in the cellulose oxide fiber and the modifying group are used. Is condensed with the amino group of the compound for introducing the amide bond to form an amide bond.

Examples of the compound for introducing a modifying group used in the step (2B) include the above-mentioned compounds.

In step (2B), the cellulose oxide fibers and the compound for introducing a modifying group are amidated in the presence of a condensing agent.

From the viewpoint of reactivity, the amount of the compound used for introducing the modifying group is such that the amine group is preferably 0.1 mol or more, more preferably 0. Mol, with respect to 1 mol of the carboxy group contained in the oxidized cellulose fiber. The amount is 5 mol or more, preferably 50 mol or less, more preferably 20 mol or less, still more preferably 10 mol or less from the viewpoint of product purity. The amount of the compound included in the above range may be subjected to the reaction at one time, or may be divided and subjected to the reaction.

The condensing agent is not particularly limited, and examples thereof include the condensing agent described in Synthetic Chemistry Series Peptide Synthesis (Maruzen Co., Ltd.) P116 or Tetrahedron, 57,1551 (2001). Dimethoxy-1,3,5-triazine-2-yl) -4-methylmorpholinium chloride (hereinafter, may be referred to as "DMT-MM") and the like can be mentioned.

In the amidation reaction, the solvent in the miniaturization step can be mentioned, and it is preferable to select a solvent in which the compound to be used dissolves.

The reaction time and reaction temperature in the amidation reaction can be appropriately selected depending on the type of compound and solvent used, but are preferably 1 to 24 hours, more preferably 10 to 20 hours from the viewpoint of reaction rate. Is. The reaction temperature is preferably 0 ° C. or higher, more preferably 5 ° C. or higher, and even more preferably 10 ° C. or higher from the viewpoint of reactivity. Further, from the viewpoint of product quality such as coloring, it is preferably 200 ° C. or lower, more preferably 80 ° C. or lower, and further preferably 30 ° C. or lower.

After the reaction, post-treatment may be appropriately performed in order to remove unreacted compounds, condensing agents and the like. As the post-treatment method, for example, filtration, centrifugation, dialysis and the like can be used.

In any of the aspects A and B, in the second manufacturing mode, except that each of the above-mentioned steps is performed in the order of step (1), step (2A) or step (2B), and miniaturization step. , Can be carried out in the same manner as in the first production form.

Further, it may be a cellulose fiber complex obtained by combining aspects A and B, that is, a cellulose fiber complex having a modifying group linked via an ionic bond and a modifying group linked via an amide bond. There may be. In this case, either step (2A) or step (2B) may be performed first.

Thus, it is possible to obtain a cellulose fiber composite in which a modifying group is linked to the cellulose fiber via an ionic bond and / or a covalent bond.

The obtained cellulose fiber composite can be used in the state of the dispersion liquid after the above-mentioned post-treatment, or the solvent is removed from the dispersion liquid by a drying treatment or the like, and the dried powdered cellulose is used. It is also possible to obtain a fiber composite and use it. Here, the “powder” is a powder in which the cellulose fiber composite is aggregated, and does not mean the cellulose particles.

Examples of the powdered cellulose fiber composite include a dried product obtained by drying the dispersion liquid of the cellulose fiber composite as it is; a powder obtained by mechanically treating the dried product; a dispersion liquid of the cellulose fiber composite is known. Powdered by the spray-drying method; Examples thereof include powdered dispersion of the cellulose fiber composite by a known freeze-drying method. The spray-drying method is a method in which a dispersion of the cellulose fiber complex is sprayed in the air and dried.

From the viewpoint of antifouling property, the average fiber diameter of the obtained cellulose fiber complex is preferably 0.1 nm or more, more preferably 0.5 nm or more, still more preferably 1 nm or more, still more preferably 2 nm or more, still more preferably. Is 3 nm or more. From the same viewpoint, it is preferably 100 nm or less, more preferably 50 nm or less, still more preferably 20 nm or less, still more preferably 10 nm or less, still more preferably 6 nm or less, still more preferably 5 nm or less.

The length (average fiber length) of the obtained cellulose fibers is preferably 150 nm or more, more preferably 200 nm or more, from the viewpoint of antifouling property. From the same viewpoint, it is preferably 1000 nm or less, more preferably 750 nm or less, still more preferably 500 nm or less, still more preferably 400 nm or less.

In the present invention, the average fiber diameter and the average fiber length of the cellulose fibers are not limited to the above ranges, and can be used even if they are on the order of a micrometer, for example.

The average aspect ratio (fiber length / fiber diameter) of the obtained cellulose fibers is preferably 1 or more, more preferably 10 or more, still more preferably 20 or more, still more preferably 40 or more, from the viewpoint of antifouling property. It is more preferably 50 or more, and from the same viewpoint, it is preferably 150 or less, more preferably 140 or less, still more preferably 130 or less, still more preferably 100 or less, still more preferably 95 or less, still more preferably 90 or less. When the average aspect ratio is within the above range, the standard deviation of the aspect ratio is preferably 60 or less, more preferably 50 or less, still more preferably 45 or less, and the lower limit is particularly low, from the viewpoint of antifouling property. Although it is not set, it is preferably 4 or more from the viewpoint of economy. The cellulose fiber having a low aspect ratio not only has excellent heat resistance, but also has excellent dispersibility in the resin composition, has high mechanical strength, and can obtain a resin composition that is brittle and difficult to break.

<Organic medium>
The organic medium used in the present invention may be hydrophilic or hydrophobic, but from the viewpoint of antifouling property, it is preferably an organic medium having an SP value of 5 or more and 25 or less.

The SP value in the present specification indicates a solubility parameter (unit: (cal / cm ³ ) ^1/2 ) calculated by the Fedors method, and for example, the reference "SP value basics / applications and calculation method" (Information Mechanism). , 2005), Polymer handbook Calculation (A Wiley-Interscience publication, 1989) and the like.

The mass average molecular weight of the organic medium having an SP value of 5 or more and 25 or less used in the present invention is not particularly limited, but is preferably 50 or more, more preferably 100 or more, and preferably 100,000 or less. , More preferably 50,000 or less, still more preferably 20,000 or less.

Examples of the hydrophobic organic medium used in the present invention include organic media having an SP value of 5 or more and less than 10, such as oleic acid (SP value: 9.2) and D-lymonen (SP value: 9). .4), Polyethylene glycols (PEG400 (SP value: 9.4), etc.), Dimethyl succinate (SP value: 9.9), Neopentyl glycol dicaprate (SP value: 8.9), Hexyl laurate (SP value: 8.9) SP value: 8.6), isopropyl laurate (SP value 8.5), isopropyl myristate (SP value 8.5), isopropyl palmitate (SP value 8.5), isopropyl oleate (SP value: 8. 6), Hexadecane (SP value: 8.0), Olive oil (SP value: 9.3), Johova oil (SP value: 8.6), Squalane (SP value: 7.9), Liquid paraffin (SP value: 9.9) 7.9), Fluorocarbons (Florinate FC-40 (3M, SP value: 6.1), Florinate FC-43 (3M, SP value: 6.1), Florinate FC-72 (3M) , SP value: 6.1), Florinate FC-770 (3M, SP value: 6.1), etc.), Silicone oils (KF-96-1cs (Shin-Etsu Chemical, SP value: 7.3)) , KF-96-10cs (manufactured by Shin-Etsu Chemical Co., Ltd., SP value: 7.3), KF-96-50cs (manufactured by Shin-Etsu Chemical Co., Ltd., SP value: 7.3), KF-96-100cs (manufactured by Shin-Etsu Chemical Co., Ltd., SP value: 7.3) SP value: 7.3), KF-96-1000cs (manufactured by Shin-Etsu Chemical Co., Ltd., SP value: 7.3), etc.) and the like can be mentioned. Among these, from the viewpoint of antifouling property, the SP value of the organic medium is preferably 9.5 or less, preferably 5 or more, more preferably 6 or more, for example, squalane, the above-mentioned polyethylene glycols. , The above-mentioned silicone oils and the like.

Further, examples of the hydrophilic organic medium used in the present invention include organic media having an SP value of 10 or more and 25 or less, and examples thereof include ethylene glycol (SP value: 14.6) and propylene glycol (SP value:). 12.6), propylene glycol monomethyl ether (SP value: 10.1), diethylene glycol (SP value: 12.1), diethylene glycol monobutyl ether (SP value: 10.2), dimethylsulfoxide (SP value: 14.5) , Dimethylformamide (SP value: 12.1), dimethylacetamide (SP value: 10.8), ethylene carbonate (SP value: 14.7), propylene-1,2-carbonate (SP value: 13.3), Heptanol (SP value: 10.6), 2-butanol (SP value: 10.8), 1,4-butanediol (SP value: 12.1), acetonitrile (SP value: 11.9), butanoic acid (SP value: 11.9) SP value: 10.5), cresol (SP value: 10.2), acetphenone (SP value: 10.6), benzyl alcohol (SP value: 12.1), glycerin (SP value: 16.5), etc. Can be mentioned. Among these, from the viewpoint of antifouling property, the SP value of the organic medium is preferably 20 or less, more preferably 18 or less, still more preferably 17 or less, and for example, ethylene glycol, propylene glycol, propylene glycol monomethyl ether. , Diethylene glycol, diethylene glycol monobutyl ether, glycerin and the like.

The content of the organic medium in the gel film of the present invention is preferably 90% by mass or more, more preferably 92% by mass or more, still more preferably 95% by mass or more, from the viewpoint of antifouling property and film durability. From the same viewpoint, it is preferably 98% by mass or less, more preferably 97% by mass or less, and further preferably 96% by mass or less.

[Method of forming a gel film on a molded product]
The method for forming a gel film on a molded product of the present invention is a step 1 of preparing a dispersion containing a cellulose fiber composite and an organic medium, and a step of applying the dispersion prepared in step 1 to the molded product. It has 2.

<Step 1>
A dispersion containing a cellulose fiber complex and an organic medium can be prepared by mixing these components with a solvent.

Examples of the solvent include isopropyl alcohol, ethanol, methyl ethyl ketone and the like.

The mixing conditions of these components are, for example, preferably 15 to 35 ° C. Further, the mixing time is preferably 10 to 60 minutes.

<Process 2>
The dispersion obtained in step 1 is applied to a molded product having a solid surface such as glass or resin. Examples of the coating method include a method of coating using an applicator, a bar coater, a spin coater, or the like. The thickness of the coating film is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 30 μm from the viewpoint of antifouling property, and preferably 2000 μm or less, more preferably 1500 μm or less, further from the viewpoint of coatability. It is preferably 1200 μm or less.

The coating is then dried. The drying conditions may be under reduced pressure or normal pressure, and the temperature range is preferably 15 to 75 ° C. The time for drying is preferably 1 to 24 hours.

In this way, a gel film is formed, and a molded product having the gel film is obtained.

[Molded product]
A molded product having a gel film can be produced as described above, and the molded product having the gel film described above is included in the present invention.

By applying the gel film of the present invention to a solid surface as described above, the solid surface can be modified into an antifouling surface. Therefore, the present invention includes the above-mentioned gel film for modifying a solid surface into an antifouling surface.

The gel film of the present invention not only has a high effect of preventing the adhesion of stains, but also can maintain the effect for a long period of time, so that it can be suitably used as an antifouling film. Here, the antifouling film means a film that does not easily adhere to dirt and can be easily washed after it has adhered. The antifouling film is used for various purposes, for example, as a packaging material for daily necessities, cosmetics, home appliances, etc., and is used for transporting and protecting blister packs, trays, packaging containers such as lunch lids, food containers, and industrial parts. It can be suitably used for a tray or the like.

[Dispersion for gel film]
As one aspect of the present invention, there is provided a dispersion for a gel film having a cellulose fiber composite in which a modifying group is bonded to a carboxy group of a cellulose fiber and an organic medium. Such a dispersion for a gel film can be provided as a coating liquid for forming a gel film. If necessary, such a dispersion for a film may contain the solvent and other components listed in the above-mentioned [Method for forming a gel film on a molded product].

From the viewpoint of antifouling property, the content of the cellulose fiber composite of the present invention in the dispersion for gel film is preferably 0.2% by mass or more, more preferably 0.3% by mass or more, still more preferably 0.4. It is mass% or more. From the same viewpoint, it is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and further preferably 1.0% by mass or less.

From the viewpoint of antifouling property, the content of the organic medium in the gel film dispersion is preferably 7.0% by mass or more, more preferably 8.0% by mass or more, still more preferably 9.0% by mass or more. .. From the same viewpoint, it is preferably 12.0% by mass or less, more preferably 11.0% by mass or less, and further preferably 10.0% by mass or less.

The content of the solvent in the dispersion for gel film is preferably 80.0% by mass or more, more preferably 85.0% by mass or more, still more preferably 88.0, from the viewpoint of sufficiently dispersing the cellulose fiber composite or the like. It is mass% or more. Further, from the viewpoint of shortening the film formation time, it is preferably 92.8% by mass or less, more preferably 91.7% by mass or less, and further preferably 90.6% by mass or less.

Hereinafter, the present invention will be specifically described with reference to Examples. It should be noted that this embodiment is merely an example of the present invention and does not mean any limitation. The part in the example is a mass part unless otherwise specified. The "normal pressure" indicates 101.3 kPa, and the "room temperature" indicates 25 ° C.

[Average fiber diameter, average fiber length, average aspect ratio of cellulose fiber composite]
Atomic force microscope is used as an observation sample after adding water to the cellulose fiber composite to prepare a dispersion having a concentration of 0.0001% by mass, dropping the dispersion onto mica (mica) and drying the mixture. (AFM, Nanoscape III Tapping mode AFM, manufactured by Digital instrument, probe uses Point Probe (NCH) manufactured by Nanosensors) is used to measure the fiber height of the cellulose fiber composite in the observation sample. At that time, in a microscope image in which the cellulose fibers can be confirmed, five or more cellulose fibers are extracted, and the average fiber diameter is calculated from the fiber heights thereof. The average aspect ratio is calculated from the average fiber length / average fiber diameter, and the standard deviation is also calculated.

[Carboxy group content of cellulose fiber and cellulose fiber complex]
Put the cellulose fiber or cellulose fiber composite having a dry mass of 0.5 g in a 100 mL beaker, add ion-exchanged water or a mixed solvent of methanol: water = 2: 1 to make a total of 55 mL, and add 5 mL of a 0.01 M sodium chloride aqueous solution to the total. In addition, a dispersion is prepared and the dispersion is stirred until the cellulose fibers or cellulose fiber composites are sufficiently dispersed. Add 0.1 M hydrochloric acid to this dispersion to adjust the pH to 2.5 to 3, and use an automatic titrator (manufactured by Toa DKK, trade name "AUT-50") to prepare a 0.05 M aqueous sodium hydroxide solution. It is added dropwise to the dispersion under the condition of a waiting time of 60 seconds, the conductivity and pH values are measured every minute, and the measurement is continued until the pH reaches about 11, to obtain an conductivity curve. From this conductivity curve, the amount of sodium hydroxide droplets is determined, and the carboxy group content of the cellulose fiber or the cellulose fiber composite is calculated by the formula 1.

Carboxy group content (mmol / g) = quantification of sodium hydroxide droplets x concentration of aqueous sodium hydroxide solution (0.05M) / mass of cellulose fibers (0.5 g) ... Equation 1

[Aldehyde group content of cellulose oxide fiber and cellulose fiber complex]
In a beaker, 100.0 g of oxidized cellulose fiber or cellulose fiber composite (solid content concentration 1.0% by mass), acetate buffer (pH 4.8), 2-methyl-2-butene 0.33 g, sodium chlorite 0 Add .45 g and stir at room temperature for 16 hours to oxidize the aldehyde group. After completion of the reaction, the reaction is carried out with ion-exchanged water to obtain an oxidized cellulose fiber or a cellulose fiber composite obtained by oxidizing an aldehyde group. The reaction solution was freeze-dried, and the carboxy group content of the obtained dried product, the oxidized cellulose fiber or the cellulose fiber composite, was measured by the method described above, and the aldehyde group was oxidized to the oxidized cellulose fiber or the cellulose fiber. Calculate the carboxy group content of the complex. Subsequently, the aldehyde group content of the oxidized cellulose fiber or the cellulose fiber complex is calculated by the formula 2.

Aldehyde group content (mmol / g) = (carboxy group content of aldehyde group oxidized cellulose oxide fiber or cellulose fiber composite)-(carboxy group content of cellulose oxide fiber or cellulose fiber composite) ... Equation 2

[Concentration of solid content in dispersion]
This is performed using a halogen moisture meter MOC-120H (manufactured by Shimadzu Corporation). Measurement is performed every 30 seconds at a constant temperature of 150 ° C. for 1 g of a sample, and the value at which the mass loss is 0.1% or less is defined as the solid content concentration.

[Average bond amount and introduction rate of modifying groups of cellulose fiber composite (ionic bond)]
The binding amount of the modifying group is determined by the following IR measurement method, and the average binding amount and introduction rate are calculated by the following formula. Specifically, the IR measurement is performed by measuring the dried cellulose fiber or the cellulose fiber composite by the ATR method using an infrared absorption spectroscope (IR) Nicolet 6700 (manufactured by Thermo Fisher Scientific Co., Ltd.), and the following formula is used. The average bond amount and introduction rate of the modifying group are calculated.
Bonding amount of modifying group (mmol / g) = [Carboxy group content of cellulose fiber (mmol / g)] × [( ^{Peak strength of 1720cm -1 of cellulose fiber −} 1720cm of cellulose fiber composite after introduction of modifying group − ¹ peak intensity) ÷ 1720 cm ^-1 peak intensity of cellulose fiber]
Peak intensity of 1720 cm ^-1 : Peak intensity derived from carbonyl group of carboxylic acid Introduction rate of modifying group (%) = {Amount of modified group bonded (mmol / g) / carboxy group content in cellulose fiber before introduction ( mmol / g)} × 100

[Average bond amount and introduction rate of modifying groups of cellulose fiber complex (amide bond)]
The average bond amount of the modifying group is calculated by the following formula.
Bonding amount of modifying group (mmol / g) = carboxy group content in cellulose fiber before introduction of modifying group (mmol / g) -carboxy group content in cellulose fiber composite after introduction of modifying group (mmol / g)
Introductory rate of modifying group (%) = {bonding amount of modifying group (mmol / g) / carboxy group content in cellulose fiber before introduction (mmol / g)} x 100

[Maldence hardness of gel film]
The gel film to be measured is measured using a microhardness tester (DUH-211 manufactured by Shimadzu Corporation). The test force is 0.1 mN, and the measurement is carried out at room temperature. The same sample is measured 10 times, and the average value is defined as Maldens hardness (N / mm ² ).

[Preparation of fine cellulose fiber dispersion]
Cellulose Fiber Preparation Example 1 (Dispersion of carboxy group-containing fine cellulose fiber obtained by reacting a natural cellulose fiber with an N-oxyl compound)
Bleached kraft pulp of softwood (Fletcher Challenge Canada, trade name "Mackenzie", CSF 650 ml) was used as a natural cellulose fiber. As the TEMPO, a commercially available product (manufactured by ALDRICH, Free radical, 98% by mass) was used. As the sodium hypochlorite, a commercially available product (manufactured by Wako Pure Chemical Industries, Ltd.) was used. As the sodium bromide, a commercially available product (manufactured by Wako Pure Chemical Industries, Ltd.) was used.

First, 100 g of softwood bleached kraft pulp fiber is sufficiently stirred with 9900 g of ion-exchanged water, and then TEMPO 1.25 mass%, sodium bromide 12.5 mass%, and sodium hypochlorite 28 are based on the pulp mass 100 g. .4% by mass was added in this order. Using a pH stud, 0.5 M sodium hydroxide was added dropwise to keep the pH at 10.5. After the reaction was carried out for 120 minutes (20 ° C.), the dropping of sodium hydroxide was stopped to obtain oxidized pulp. The obtained oxidized pulp was thoroughly washed with ion-exchanged water, and then dehydrated. Then, 3.9 g of oxidized pulp and 296.1 g of ion-exchanged water were refined twice at 245 MPa using a high-pressure homogenizer (Sugino Machine Limited, Starburst Lab HJP-2 5005), and carboxy group-containing fine cellulose fibers were subjected to two times. A dispersion liquid (solid content concentration 1.3% by mass) was obtained. The average fiber diameter of the fine cellulose fibers was 3.3 nm, and the carboxy group content was 1.62 mmol / g.

Preparation Example 2 of Fine Cellulose Fiber (Dispersion of carboxy Group-Containing Fine Cellulose Fiber in which Aldehyde Group is Reduced)
3846.15 g (solid content concentration: 1.3% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 1 was put into a beaker, and a 1M aqueous sodium hydroxide solution was added thereto to adjust the pH to about 10, and then hydrogen was added. 2.63 g of sodium borohydride was charged and reacted at room temperature for 3 hours for aldehyde reduction treatment. After completion of the reaction, 405 g of 1 M hydrochloric acid aqueous solution and 4286 g of ion-exchanged water were added to make a 0.7 mass% aqueous solution, which was reacted at room temperature for 1 hour for protonation. After the reaction was completed, it was washed with ion-exchanged water to remove hydrochloric acid and salt. Removed. Finally, the solvent was replaced with isopropyl alcohol to obtain a carboxy group-containing fine cellulose fiber dispersion in which the aldehyde group was reduced. The obtained carboxy group-containing fine cellulose fiber dispersion (solid content concentration: 2.0% by mass) obtained by reducing the aldehyde group had an average fiber diameter of 3.3 nm and a carboxy group content of 1.62 mmol / g.

[Preparation of cellulose fiber complex]
Manufacturing example 1
A beaker equipped with a magnetic stirrer and a stirrer was charged with 300 g (solid content concentration: 2.0% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 2. Subsequently, amino-modified silicone (BY16-209, manufactured by Toray Dow Corning Co., Ltd., abbreviated as "silicone 1") is charged in an amount corresponding to 0.5 mol of amino groups with respect to 1 mol of carboxy groups of cellulose fibers. , 100 g of isopropyl alcohol was added and the mixture was reacted at room temperature (25 ° C.) for 14 hours. After completion of the reaction, the mixture is filtered, washed with isopropyl alcohol, stirred with an ultrasonic homogenizer (US-300E, manufactured by Nippon Seiki Seisakusho Co., Ltd.) for 2 minutes, and then stirred with a high-pressure homogenizer (manufactured by Sugino Machine Limited, Starburst Lab HJP-2 5005). By finely treating the fine cellulose fibers at 100 MPa for 1 pass and 150 MPa for 9 passes, a cellulose fiber composite in which the amino-modified silicone was linked via an ionic bond to the reduced fine cellulose fibers was obtained. The introduction rate of the modifying group was 40% of the carboxy group of the fine cellulose fiber.

Production Examples 2-3
A cellulose fiber complex was obtained in the same manner as in Production Example 1 except that the compound for introducing the modifying group was changed as shown in Table 1.

Manufacturing example 4
A beaker equipped with a magnetic stirrer and a stirrer was charged with 300 g (solid content concentration: 2.0% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 2. Subsequently, dodecylamine was charged in an amount corresponding to 1.0 mol of an amino group with respect to 1 mol of the carboxy group of the cellulose fiber, 100 g of isopropyl alcohol was added, and the mixture thereof was reacted at room temperature (25 ° C.) for 14 hours. .. After completion of the reaction, the mixture is filtered, washed with isopropyl alcohol, stirred with an ultrasonic homogenizer (US-300E, manufactured by Nippon Seiki Seisakusho Co., Ltd.) for 2 minutes, and then stirred with a high-pressure homogenizer (manufactured by Sugino Machine Limited, Starburst Lab HJP-2 5005). By finely treating the fine cellulose fibers at 100 MPa for 1 pass and 150 MPa for 9 passes, a cellulose fiber composite in which dodecylamine groups were linked via ionic bonds to the reduced fine cellulose fibers was obtained. The introduction rate of the modifying group was 90% of the carboxy group of the fine cellulose fiber.

Production example 5
A cellulose fiber complex was obtained in the same manner as in Production Example 4 except that the compound for introducing the modifying group was changed as shown in Table 1.

The details of the compound for introducing the modifying group in Table 1 are as follows.
Silicone 2: Toray Dow Corning Co., Ltd., SF8417
Silicone 3: Toray Dow Corning Co., Ltd., FZ-3760
Dodecylamine: manufactured by Wako Pure Chemical Industries, Ltd. Oleylamine: manufactured by Wako Pure Chemical Industries, Ltd. In Table 1, the amount charged is the amount of amino groups (mol) with respect to 1 mol of carboxy groups.

[Preparation of gel film with organic medium]
Example 1
Using the cellulose fiber complex obtained in Production Example 1, a gel film was prepared as follows. Cellulose fiber composite, glycerin and solvent so that the mass ratio of cellulose fibers: glycerin (organic medium) in the cellulose fiber composite is 1:20 and the solvent is 90% by mass of the entire dispersion. (Isopropyl alcohol) was added, and the mixture was stirred in a screw tube at room temperature for 30 minutes. Then, using an automatic revolution type stirrer, Awatori Rentaro (manufactured by Shinky Co., Ltd.), the mixture was stirred at 2200 rpm for 2 minutes to defoam, and a dispersion for a coating film was obtained. The obtained dispersion for coating film was coated on a glass substrate (Micro Slide Glass S2112, manufactured by MATSUNAMI) using an applicator (manufactured by Tester Sangyo Co., Ltd.) so as to have a thickness of 100 μm, and under vacuum at 50 ° C. By drying for 12 hours, isopropyl alcohol, which accounts for 90% of the total, was volatilized to obtain a gel film having a thickness of 10 μm.

Examples 2-11 and Comparative Examples 1-2
A gel film was prepared in the same manner as in Example 1 except that the type of the organic medium and / or the type of the cellulose fiber complex was changed as shown in Table 2. The results are shown in Table 2. The muldens hardness of the gel film obtained in Example 3 was measured as described above and found to be 2.6 (N / mm ² ).

[Cleaning test]
To various membranes formed on a glass substrate, 0.3 g of lard (manufactured by SIGMA-ALDRICH), which was warmed and fluidized in a water bath at a water temperature of 70 ° C., was ^{applied per 10 cm 2 of} the membrane area, and at room temperature for 2 hours. I left it. Then, the substrate was washed by exposing it to tap water having a water temperature of 25 ° C. and a flow rate of 5 L / min for 5 seconds. After cleaning, the substrate was dried overnight at room temperature, and the cleaning rate (%) was calculated from the formula shown below.

In Table 2, the mass ratio is the mass ratio of the cellulose fibers in the cellulose fiber composite to the organic medium (cellulose fiber: organic medium).

The PEG400 used above is polyethylene glycol (made by Wako Pure Chemical Industries, Ltd., PEG400).

From the above table, we found the following. It was found that all the membranes of the examples had a high cleaning rate and were excellent as gel membranes, especially antifouling membranes. On the other hand, it was found that the films of Comparative Examples 1 and 2 had a low cleaning rate and could not be used as an antifouling film.

The gel film of the present invention can be used in the field of cosmetics and food packaging containers. In particular, the gel film of the present invention can be suitably used in such fields as an antifouling film.

Claims (5)

An antifouling gel film having a cellulose fiber composite in which a modifying group is bonded to a carboxy group of a cellulose fiber having a carboxy group content of 0.1 mmol / g or more and an organic medium. The antifouling gel film according to claim 1, wherein the modifying group is at least one selected from the group consisting of a hydrocarbon group and a silicone group. The antifouling gel according to any one of claims 1 to 3, wherein the mass ratio of the cellulose fibers to the organic medium (cellulose fiber: organic medium) in the cellulose fiber composite is 1: 1 to 1:50. film. The antifouling gel film according to any one of claims 1 to 3, which is for a packaging container. A dispersion for an antifouling gel membrane having a cellulose fiber composite in which a modifying group is bonded to a carboxy group of a cellulose fiber having a carboxy group content of 0.1 mmol / g or more and an organic medium.