JP5296445B2 - Gel composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gel-like composition which can hold high viscosity even in the coexistence of a salt, an ionic surfactant, or the like. <P>SOLUTION: There is provided the gel-like composition using the following components (A) and (B), characterized in that the content of the component (A) is 0.3 to 5.0 wt.% based on the total amount of the gel-like composition. (A) Cellulose fibers having the maximum fiber diameter of &le;1,000 nm and a number-average fiber diameter of 2 to 150 nm, wherein the cellulose has a cellulose type I crystal structure, and hydroxy groups at the C6 positions of glucose units in the cellulose molecule are selectively oxidized into aldehyde groups and carboxy groups to give the aldehyde groups and the carboxyl groups in amounts of 0.08 to 0.3 mmol/g and 0.6 to 2.0 mmol/g, respectively. (B) Water. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a gel composition comprising cellulose fibers.

  Conventional thickeners and gelling agents include natural polymer compounds such as duran gum, carrageenan, agar, and xanthan gum, nonionic water-soluble celluloses such as methylcellulose and hydroxymethylcellulose, ions such as carboxymethylcellulose and cationized cellulose. Synthetic polymers such as water-soluble cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyethylene glycol, and water-swellable clay minerals such as smectite have been used.

  However, since the above natural polymer compound has low solubility in water, heat treatment of water is required during the production process of the gel composition, and the problem of poor productivity, or when adding a fragrance, etc. There was a problem that some of them volatilized. On the other hand, since the nonionic water-soluble cellulose has high solubility in water, heat treatment of water is unnecessary, but it is necessary to add a large amount of water-soluble cellulose to obtain a gel-like product. There was a problem. In addition, synthetic polymers such as poly (sodium acrylate) and carboxyvinyl polymer have the trouble that care must be taken not to become a spatter (Mamako) or pH adjustment when dispersing or dissolving. . Further, it is disclosed that the above xanthan gum has a strong spinnability and has a sticky feeling when used in cosmetics and the like (Non-Patent Document 1). Many of these natural polymer compounds, water-soluble celluloses, and synthetic polymers have many problems in the range of use and design properties, such as markedly lowering viscosity due to the coexisting salts, and showing stringiness.

Accordingly, a nasal gel using a carboxyvinyl polymer as a gelling agent has been proposed, and it has been disclosed that this improves dripping and has effects such as promoting absorption of medicinal ingredients (patent document). 1). In addition, it is disclosed that cellulose particles downsized to several tens of nm have high transparency, and high viscosity, dispersion / emulsion stability, and structural stability can be obtained with a small addition amount (Patent Documents). 2).
“Latest Trends in Polymer Gels” supervised by Mitsuhiro Shibayama and Satoshi Sugawara, CMC Publishing, April 30, 2004, p. 216-226 JP 2001-89359 A International Publication No. 99/28350

  However, those described in Patent Document 1 require that pH adjustment is required with a basic substance at the time of preparation, and that strong stirring is performed in order to uniformly mix and disperse the medicinal ingredients on the highly viscous base material. There are also manufacturing difficulties such as necessity. In addition, the cellulose particles described in Patent Document 2 not only have a reduced viscosity in the presence of electrolytes such as salts and high-concentration ionic surfactants, but the cellulose particles settle to form a dispersion. There were difficulties such as being unable to take.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a gel composition that can maintain high viscosity even in the presence of a salt, an ionic surfactant, or the like.

In order to achieve the above object, the gel composition of the present invention is a gel composition using the following components (A) to ( C ), and the content of the component (A) is a gel. It takes the structure that it is set to the range of 0.3 to 5.0 weight% of the whole composition.
(A) A cellulose fiber having a maximum fiber diameter of 1000 nm or less and a number average fiber diameter of 2 to 150 nm, the cellulose having a cellulose I-type crystal structure and a hydroxyl group at the C6 position of the glucose unit in the cellulose molecule Is a cellulose fiber which is selectively oxidized to be modified into an aldehyde group and a carboxyl group, and has 0.08 to 0.3 mmol / g of the aldehyde group and 0.6 to 2.0 mmol / g of the carboxyl group.
(B) Water.
(C) At least one functional additive selected from the group consisting of inorganic salts, surfactants, oils, humectants, preservatives, organic fine particles, inorganic fine particles, deodorants, perfumes and organic solvents.

  That is, the present inventors have conducted extensive research in order to obtain a gel-like composition that can maintain high viscosity even in the presence of a salt, an ionic surfactant, or the like. In the course of the research, the maximum fiber diameter is 1000 nm or less, the number average fiber diameter is 2 to 150 nm, it has a cellulose I-type crystal structure, and the hydroxyl group at the C6 position of the glucose unit in the cellulose molecule is selectively oxidized. Attention was focused on fine cellulose fibers that have been modified to aldehyde groups and carboxyl groups. Then, specific fine cellulose fibers (water-insoluble cellulose fibers) having 0.08 to 0.3 mmol / g of the aldehyde group and 0.6 to 2.0 mmol / g of the carboxyl group are mixed with water as a liquid dispersion medium. A gel-like composition formed by combining with was found. About this gel-like composition, when it repeated experiment about preferable content of the said specific cellulose fiber, content of a specific cellulose fiber is the range of 0.3 to 5.0 weight% of the whole gel-like composition. In some cases, it has been found that the intended purpose can be achieved, and the present invention has been achieved.

As described above, the gel composition of the present invention is a cellulose fiber having a maximum fiber diameter of 1000 nm or less and a number average fiber diameter of 2 to 150 nm, and the cellulose has a cellulose I-type crystal structure and cellulose. The hydroxyl group at the C6 position of the glucose unit in the molecule is selectively oxidized and modified to an aldehyde group and a carboxyl group, the aldehyde group is 0.08 to 0.3 mmol / g, and the carboxyl group is 0.6 to 2. Fine cellulose fibers (A) having 0 mmol / g, water (B) as a liquid dispersion medium, and a specific functional additive (C) are used. And since content of the said fine cellulose fiber is the range of 0.3 to 5.0 weight% of the whole gel-like composition, it is high-viscosity also in coexistence with a salt, an ionic surfactant, etc. The gel state can be maintained without causing water separation or the like. In addition, the gel composition of the present invention is excellent in usability because it has no spinnability and can be easily mixed with various functional additives.

  In addition, since the gel composition of the present invention can sufficiently maintain viscosity even in a high temperature environment, for example, the use in which the vehicle interior temperature becomes a high temperature of 70 ° C. or higher (air fresheners and deodorizers for automobiles). , Deodorant, etc.). Natural polysaccharide gelling agents such as gelatin and agarose cause gel-sol transition at high temperatures and cannot maintain the viscosity as a gel, and thus are not suitable for such applications.

And since the gel-like composition formed using the said specific cellulose fiber and water (liquid dispersion medium) is rich also in the compounding property with specific functional additives, such as inorganic salts and surfactant, It can be widely and suitably used as a cosmetic base material and a gel base material for toiletries such as fragrances.

  Further, when the cellulose fiber of the component (A) is obtained by oxidizing a part of the hydroxyl group of the cellulose fiber to a carboxyl group and an aldehyde group using a co-oxidant in the presence of an N-oxyl compound. By adjusting the amount of oxidizing agent used and the oxidation time, the oxidized and modified functional group can be adjusted to a specific range, and a better result can be obtained as a gel composition. .

  Next, embodiments of the present invention will be described in detail.

The gel composition of the present invention comprises a specific cellulose fiber (component A), water (component B), and a specific functional additive (C) .

  Here, in the present invention, the maximum characteristic is that the content of the specific cellulose fiber (component A) is in the range of 0.3 to 5.0% by weight of the entire gel composition, preferably Is in the range of 0.5 to 3.0% by weight. That is, when the content of the component A is within the above range, high viscosity can be maintained even in the presence of a salt or an ionic surfactant. On the other hand, when the content of the A component is less than 0.3% by weight, when the functional additive is blended, it does not become a gel but exhibits fluidity, and conversely, the content of the A component is 5. If it exceeds 0% by weight, the viscosity becomes very high, and it is impossible to obtain a fine composition in the dispersion process, and a gel-like composition cannot be obtained substantially because it is not a macroscopically homogeneous gel-like composition. is there.

  The specific fine cellulose fiber (component A) used in the present invention is a cellulose fiber in which a part of the hydroxyl group of the cellulose fiber is oxidized to a carboxyl group and an aldehyde group, the maximum fiber diameter is 1000 nm or less, and the number average The fiber diameter is 2 to 150 nm, preferably the maximum fiber diameter is 500 nm or less and the number average fiber diameter is 2 to 100 nm, particularly preferably the maximum fiber diameter is 30 nm or less and the number average fiber diameter is 2 to 10 nm. is there. That is, when cellulose fibers having a maximum fiber diameter of more than 1000 nm or a number average fiber diameter of more than 150 nm are used, the cellulose fibers settle and retain fluidity and do not become a gel.

  Here, the analysis of the maximum fiber diameter and the number average fiber diameter can be performed, for example, as follows. That is, an aqueous dispersion of fine cellulose having a solid content of 0.05 to 0.1% by weight was prepared, and the dispersion was cast on a carbon film-coated grid that had been subjected to a hydrophilization treatment. (TEM) observation sample. In addition, when the fiber of the big fiber diameter outside this invention is included, you may observe the scanning electron microscope (SEM) image of the surface cast on glass. Then, observation with an electron microscope image is performed at a magnification of 5000 times, 10000 times, or 50000 times depending on the size of the constituent fibers. At that time, an axis having an arbitrary vertical and horizontal image width is assumed in the obtained image, and the sample and observation conditions (magnification, etc.) are adjusted so that 20 or more fibers intersect the axis. Then, after obtaining an observation image that satisfies this condition, two random axes, vertical and horizontal, per image are drawn on this image, and the fiber diameter of the fiber that intersects the axis is visually read. In this way, images of at least three non-overlapping surface portions are taken with an electron microscope, and the fiber diameter values of the fibers intersecting with each of the two axes are read (thus, at least 20 × 2 × 3 = 120). Information on the fiber diameter of the book is obtained). The maximum fiber diameter and the number average fiber diameter are calculated from the fiber diameter data thus obtained.

  Next, the amount of carboxyl group and aldehyde group of the specific cellulose fiber (component A) used in the present invention will be described. In general, it is preferable that the total amount of carboxyl groups and aldehyde groups present in cellulose is large, because it can be stably present as a finer fiber diameter. In the present invention, the amount of the aldehyde group in the specific cellulose fiber (component A) is 0.08 to 0.3 mmol / g, because the viscosity can be increased with a small addition amount, and The amount of the carboxyl group is set in the range of 0.6 to 2.0 mmol / g, preferably the amount of the aldehyde group is 0.10 to 0.25 mmol / g and the amount of the carboxyl group is 0. The range is from 8 to 1.6 mmol / g. That is, when the amount of the carboxyl group and the amount of the aldehyde group are set in the above ranges, the specific cellulose fiber (component A) is stably present in the gel without causing aggregation and precipitation.

  In addition, adjustment of the amount of desired carboxyl groups and aldehyde groups can be performed by controlling the addition amount and reaction time of a co-oxidant used in the cellulose fiber oxidation step, as will be described later.

  Here, the amount of the carboxyl group and the amount of aldehyde group can be measured by potentiometric titration as follows.

[Measurement of carboxyl group content]
60 ml of a 0.5 to 1 wt% slurry was prepared from a dry-weighted cellulose sample, and the pH was adjusted to about 2.5 with a 0.1 M aqueous hydrochloric acid solution, and then a 0.05 M aqueous sodium hydroxide solution was added dropwise. Then, conduct electrical conductivity measurement. The measurement is continued until the pH is about 11. A functional group amount 1 (carboxyl group amount) can be determined from the amount (V) of sodium hydroxide consumed in the neutralization step of the weak acid whose electrical conductivity changes slowly, according to the following equation (1).

[Measurement of aldehyde group content]
The cellulose sample was oxidized in a 2% aqueous sodium chlorite solution adjusted to pH 4-5 with acetic acid at room temperature (25 ° C.) for 48 hours, and the functional group amount 2 was measured according to the above formula (1). To do. Then, the amount of functional group added by this oxidation (functional group amount 2 -functional group amount 1) is calculated and used as the aldehyde group amount.

And it can confirm that the aldehyde group or the carboxyl group is introduce | transduced into the cellulose of the said specific cellulose fiber as follows. That is, in a sample from which moisture was completely removed, absorption due to a carbonyl group (near 1608 cm ⁻¹ ) and absorption due to an acid-type carboxyl group (COOH) were analyzed by total reflection infrared spectroscopy (ATR) analysis ( 1730 cm ⁻¹ )) can be confirmed.

  Next, the specific cellulose fiber (component A) can be obtained, for example, by performing (1) an oxidation reaction step, (2) a purification step, (3) a dispersion step (a refinement treatment step), and the like. Hereinafter, each process is demonstrated in order.

(1) Oxidation reaction step After natural cellulose and an N-oxyl compound are dispersed in water (dispersion medium), a co-oxidant is added to start the reaction. During the reaction, a 0.5 M aqueous sodium hydroxide solution is added dropwise to maintain the pH at 10 to 11, and the reaction is regarded as completed when no change in pH is observed. Here, the co-oxidant is not a substance that directly oxidizes a cellulose hydroxyl group but a substance that oxidizes an N-oxyl compound used as an oxidation catalyst.

  The natural cellulose means purified cellulose isolated from a cellulose biosynthetic system such as a plant, animal, or bacteria-producing gel. More specifically, softwood pulp, hardwood pulp, cotton pulp such as cotton linter and cotton lint, non-wood pulp such as straw pulp and bagasse pulp, bacterial cellulose (BC), cellulose isolated from sea squirt, seaweed Cellulose isolated from can be mentioned. These may be used alone or in combination of two or more. Among these, soft wood pulp, hardwood pulp, cotton pulp such as cotton linter and cotton lint, and non-wood pulp such as straw pulp and bagasse pulp are preferable. The natural cellulose is preferably subjected to a treatment for increasing the surface area such as beating, because the reaction efficiency can be increased and the productivity can be increased. In addition, if the natural cellulose that has been stored after being isolated and purified and not dried (never dry) is used, the microfibril bundles are likely to swell. This is preferable because the number average fiber diameter after the crystallization treatment can be reduced.

  The dispersion medium of natural cellulose in the above reaction is water, and the concentration of natural cellulose in the reaction aqueous solution is arbitrary as long as the reagent (natural cellulose) can be sufficiently diffused. Usually, it is about 5% or less with respect to the weight of the reaction aqueous solution, but the reaction concentration can be increased by using an apparatus having a strong mechanical stirring force.

  Examples of the N-oxyl compound include compounds having a nitroxy radical generally used as an oxidation catalyst. The N-oxyl compound is preferably a water-soluble compound, more preferably a piperidine nitroxyoxy radical, particularly 2,2,6,6-tetramethylpiperidinooxy radical (TEMPO) or 4-acetamido-TEMPO. preferable. The N-oxyl compound is added in a catalytic amount, preferably 0.1 to 4 mmol / l, more preferably 0.2 to 2 mmol / l.

  Examples of the co-oxidant include hypohalous acid or a salt thereof, hypohalous acid or a salt thereof, perhalogen acid or a salt thereof, hydrogen peroxide, a perorganic acid, and the like. These may be used alone or in combination of two or more. Of these, alkali metal hypohalites such as sodium hypochlorite and sodium hypobromite are preferable. And when using the said sodium hypochlorite, it is preferable in terms of reaction rate to advance reaction in presence of alkali bromide metals, such as sodium bromide. The addition amount of the alkali metal bromide is about 1 to 40 times mol, preferably about 10 to 20 times mol for the N-oxyl compound.

  The pH of the aqueous reaction solution is preferably maintained in the range of about 8-11. The temperature of the aqueous solution is arbitrary at about 4 to 40 ° C., but the reaction can be performed at room temperature (25 ° C.), and the temperature is not particularly required to be controlled.

  In order to obtain the target amount of carboxyl group and amount of aldehyde group, the degree of oxidation is controlled by the amount of co-oxidant added and the reaction time. Usually, the reaction time is completed within about 5 to 120 minutes, at most 240 minutes.

(2) Purification step Next, purification is performed for the purpose of removing unreacted co-oxidant (such as hypochlorous acid) and various by-products. At this stage, the reactant fibers are usually not dispersed evenly to the nanofiber unit. Therefore, by repeating the usual purification method, that is, washing with water and filtration, the reactant fibers are highly purified (99% by weight or more). Use water dispersion.

  As the purification method in the purification step, any device may be used as long as it can achieve the above-described object, such as a method using centrifugal dehydration (for example, a continuous decanter). The aqueous dispersion of the reactant fibers thus obtained is in the range of approximately 10 wt% to 50 wt% as the solid content (cellulose) concentration in the squeezed state. Considering the subsequent dispersion step, if the solid content concentration is higher than 50% by weight, it is not preferable because extremely high energy is required for dispersion.

(3) Dispersion process (miniaturization process)
The reaction fiber (water dispersion) impregnated with water obtained in the purification step is dispersed in a dispersion medium and subjected to a dispersion treatment. With the treatment, the viscosity increases, and a dispersion of finely pulverized cellulose fibers can be obtained. Then, the specific cellulose fiber (A component) can be obtained by drying the dispersion of the cellulose fiber. The cellulose fiber dispersion may be used in the gel composition in the state of dispersion without drying.

  And water (B component) is used for the dispersion medium of the specific cellulose fiber (A component) obtained as mentioned above.

  Dispersers used in the above dispersion process include high-powered homomixers, high-pressure homogenizers, ultra-high-pressure homogenizers, ultrasonic dispersion processing, beaters, disk type refiners, conical type refiners, double disk type refiners, grinders, etc. By using an apparatus having a beating ability, it is preferable in that a more efficient and advanced downsizing is possible, and a gel-like composition can be obtained economically advantageously. As the disperser, for example, a screw mixer, a paddle mixer, a disper mixer, a turbine mixer, or the like may be used.

  As a drying method of the cellulose fiber dispersion, for example, when the dispersion medium is water, spray drying, freeze drying, or the like is used. When the dispersion medium is a mixed solution of water and an organic solvent, a drum is used. A drying method using a dryer, a spray drying method using a spray dryer, or the like is used.

Incidentally, the gel composition of the present invention, the specific cellulose fibers (A component) and with water (B component), the specific functional additives (C component) Ru is used. As the specific functional additives, no machine salts, organic salts, surfactants, oils, humectants, preservatives, organic fine particles, inorganic fine particles, deodorants, perfumes, organic solvents are used. These may be used alone or in combination of two or more.

The inorganic salts are preferably those that can be dissolved / dispersed in water (component B), for example, salts made of alkali metal, alkaline earth metal, transition metal, hydrogen halide, sulfuric acid, carbonic acid, etc. Specifically, NaCl, KCl, CaCl ₂ , MgCl ₂ , (NH ₄ ) ₂ SO ₄ , Na ₂ CO _{3 and the} like can be mentioned. These may be used alone or in combination of two or more.

  The organic salts are substantially water-soluble by neutralizing hydroxides such as alkali metals and alkaline earth metals, and organic amines and carboxyl groups, phosphoric acid groups and sulfonic acid groups present in the molecule. Any substance that exhibits water dispersibility can be used without particular limitation.

  The surfactant is preferably one that can be dissolved / dispersed in water (component B), but is not particularly limited. For example, sulfonic acid series such as alkylsulfosuccinic acid soda, alkylsulfonic acid soda, alkyl sulfate ester salt, etc. Nonionic surfactants such as surfactants, phosphate ester surfactants such as polyoxyethylene alkyl phosphate esters, alkylene oxide adducts of higher alcohols, alkylene oxide adducts of alkylarylphenols, and the like. These may be used alone or in combination of two or more.

  Examples of the oils include silicone oils such as methylpolysiloxane and silicone polyether copolymer, vegetable oils such as olive oil and castor oil, animal oils, lanolin, liquid paraffin, squalane and the like. These may be used alone or in combination of two or more.

  Examples of the humectant include hyaluronic acid, glycerin, 1,3-butylene glycol, sorbitol, dipropylene glycol and the like. These may be used alone or in combination of two or more.

  Examples of the organic fine particles include styrene-butadiene latex, acrylic emulsion, urethane emulsion and the like. These may be used alone or in combination of two or more.

  Examples of the inorganic fine particles include titanium oxide, silica compounds, and carbon black. These may be used alone or in combination of two or more.

  Examples of the preservative include methyl paraben and ethyl paraben, and these may be used alone or in combination of two or more.

  Examples of the deodorant / fragrance include D limonene, decyl aldehyde, menthone, pulegone, eugenol, cinnamaldehyde, benzaldehyde, menthol, peppermint oil, lemon oil, orange oil, plants (for example, burdock, wolfberry, tsuga, ginkgo biloba) , Deodorized active ingredients extracted from water, hydrophilic organic solvents, etc. from various organs such as black pine, larch, red pine, giraffe, holly mushroom, lilac, buttercup, hornbill, camellia and forsythia. These may be used alone or in combination of two or more.

  Examples of the organic solvent include water-soluble alcohols (methanol, ethanol, isopropanol, isobutanol, sec-butanol, tert-butanol, methyl cellosolve, ethyl cellosolve, ethylene glycol, glycerin, etc.), ethers (ethylene Glycol dimethyl ether, 1,4-dioxane, tetrahydrofuran and the like), ketones (acetone, methyl ethyl ketone), N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide and the like. These may be used alone or in combination of two or more.

Moreover, it is preferable to use the compounding quantity of the said specific functional additive (C component) by the compounding quantity required in order to express the effect for which a functional additive aims, and it does not specifically limit.

The gel composition of the present invention is, for example, appropriately blending a specific functional additive (C component) together with the specific cellulose fiber (component A) and water (component B), and mixing these and the like. Can be obtained.

  Examples of the mixing treatment include various homogenizers such as vacuum homomixers, dispersers, propeller mixers, kneaders, various pulverizers, blenders, homogenizers, ultrasonic homogenizers, colloid mills, pebble mills, bead mill pulverizers, high-pressure homogenizers, and ultrahigh pressures. Examples thereof include a mixing process using a homogenizer or the like.

  The viscosity of the gel composition of the present invention thus obtained is preferably 15 Pa · s or more, particularly preferably in the range of 30 to 150 Pa · s.

  The viscosity can be measured using, for example, a BH viscometer (No. 4 rotor).

Here, the amount of the water (component B) is used in such a range that the content of the specific cellulose fiber (component A) is 0.1 to 5.0% by weight of the entire gel composition. It is done. That is, the gel composition of the present invention, and the specific cellulose fibers (A component), the water (B component) outside than, since it contains a specific functional additive (C component), the composition The remaining amount excluding the content of specific cellulose fiber (component A) (0.1 to 5.0% by weight) and the content of specific functional additive (component C) from the whole is water (component B) ).

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

  First, prior to examples and comparative examples, cellulose fibers S1 to S3 for examples and cellulose fibers H1 and H2 for comparative examples were produced as follows.

[Production of Cellulose Fiber S1 (for Examples)]
(1) Oxidation process Undried sulfite bleached softwood pulp (mainly consisting of fibers with a fiber diameter exceeding 1000 nm), TEMPO 2.5 g, and sodium bromide 25 g in 1500 ml water are dispersed in an amount equivalent to 200 g dry weight. Thereafter, a 13 wt% sodium hypochlorite aqueous solution was added to 1.0 g of pulp so that the amount of sodium hypochlorite was 5.4 mmol to initiate the reaction. During the reaction, a 0.5 M aqueous sodium hydroxide solution was added dropwise to maintain the pH at 10 to 11, and the reaction was regarded as completed when no change in pH was observed (reaction time: 120 minutes).

(2) Purification step After the reaction product was filtered with a glass filter, it was washed with a sufficient amount of ion-exchanged water and filtered, and the electrical conductivity of the obtained filtrate was measured. The purification process was completed when the electrical conductivity of the filtrate ceased to change even after repeated washing with water. Thus, cellulose fiber S1 with a solid content of 15% by weight containing water was obtained.

[Production of Cellulose Fibers S2, S3 (for Examples) and Cellulose Fibers H1, H2 (for Comparative Examples)]
Cellulosic fibers S2, S3, H1, and H2 were produced in accordance with the production of cellulose fiber S1, except that the amount of sodium hypochlorite to be added and the reaction time were changed as shown in Table 1 below.

  Using the thus obtained cellulose fibers S1 to S3, H1, and H2, each item was measured according to the following criteria. These results are also shown in Table 1 above.

[Maximum fiber diameter, number average fiber diameter]
Water was added to the cellulose fibers S1 to S3 and H1 and H2 to form a 2% by weight slurry, and a finer treatment was performed at a rotational speed of 8,000 rpm for 10 minutes using a disper mixer. The maximum fiber diameter and the number average fiber diameter of each cellulose fiber were observed using a transmission electron microscope (TEM) (JEM-1400, manufactured by JEOL Ltd.). That is, from the TEM image (magnification: 10000 times) negatively stained with 2% uranyl acetate after each cellulose fiber was cast on a carbon film-coated grid that had been hydrophilized, the maximum fiber diameter and The number average fiber diameter was calculated.

[Measurement of carboxyl group content]
60 ml of a slurry that has been treated for about 10 minutes using the above Disper mixer is prepared, and the pH is adjusted to about 2.5 with a 0.1 M aqueous hydrochloric acid solution, and then a 0.05 M aqueous sodium hydroxide solution is added dropwise. The electrical conductivity was measured. The measurement was continued until the pH was about 11. From the amount (V) of sodium hydroxide consumed in the weak acid neutralization stage where the change in electrical conductivity is slow, the functional group amount 1 (carboxyl group amount) was determined according to the following formula (1).

[Measurement of aldehyde group content]
The cellulose fiber is oxidized at room temperature (25 ° C.) for 48 hours in a 2% sodium chlorite aqueous solution adjusted to pH 4 to 5 with acetic acid, and the functional group amount 2 is measured according to the above formula (1). did. And the amount of functional groups added by this oxidation (functional group amount 2 -functional group amount 1) was calculated, and the amount of aldehyde groups was determined.

[Confirmation of cellulose I type crystal structure, carboxyl group, aldehyde group]
From a wide-angle X-ray diffraction image of transparent film-like cellulose obtained by drying a part of the slurry, it was confirmed to have a cellulose I-type crystal structure. Further, in the total reflection infrared spectroscopic spectrum (ATR), there may be absorption caused by a carbonyl group (near 1608 cm ⁻¹ ) and absorption caused by an acid-type carboxyl group (COOH) (near 1730 cm ⁻¹ ). confirmed.

[ Reference Examples 1-9, Comparative Reference Examples 1-8]
Water is added to form a slurry so that the concentrations of the cellulose fibers S1 to S3, H1, and H2 are in the ratios shown in Table 2 below, and fine for 10 minutes at a rotational speed of 8,000 rpm using a disper mixer. Each sample was obtained by performing a chemical conversion treatment. In Table 2, the remaining amount excluding the addition amount of cellulose fiber is the addition amount of water (hereinafter the same).

  Using each sample thus obtained, each characteristic was evaluated according to the following criteria. These results are also shown in Table 2 above.

(Measurement of viscosity)
Each sample (composition) obtained was allowed to stand at 25 ° C. for 24 hours, and then rotated at 2.5 rpm using a BH viscometer (No. 4 rotor) (manufactured by Toki Sangyo Co., Ltd., BH viscometer). The viscosity was measured at 3 minutes).

[Gel state]
The state of the gel after 1 day, 1 week, and 2 weeks was visually observed. The evaluation was made as “◯” for the gel state, “x” for the liquid (with fluidity), and “separated” after water separation from the gel.

From the results in Table 2, cellulose fibers S1 to S3 having an aldehyde group amount of 0.08 to 0.3 mmol / g and a carboxyl group amount of 0.6 to 2.0 mmol / g were used, and the cellulose The products of Reference Examples 1 to 9 having a fiber content of 0.3 to 5.0% by weight maintained a gel state even after being stored for 2 weeks.

In contrast, cellulose fibers S1 to S3 having an aldehyde group amount of 0.08 to 0.3 mmol / g and a carboxyl group amount of 0.6 to 2.0 mmol / g are used. Comparative Reference Examples 1, 3 and 5 having a content of less than the lower limit (0.3% by weight) did not enter a gel state. In addition, cellulose fibers S1 to S3 having an aldehyde group amount of 0.08 to 0.3 mmol / g and a carboxyl group amount of 0.6 to 2.0 mmol / g are used. In Comparative Reference Examples 2, 4, and 6 exceeding the upper limit (5.0% by weight), the viscosity was too high, so that uniform dispersion could not be performed and a gel-like product could not be prepared.

Further, the product of Comparative Reference Example 7 using the cellulose fiber H1 having a carboxyl group amount of less than 0.6 mmol / g was separated after 1 day, with some cellulose fibers being separated. In Comparative Reference Example 8 products using cellulose fibers H2 having a carboxyl group amount exceeding 2.0 mmol / g, the gel state could not be maintained over time, and fluidity was developed.

  Next, a gel composition was prepared using the cellulose fibers, water (liquid dispersion medium), and functional additives (inorganic salts and the like).

[Examples 1 to 2 13 and Comparative Examples 1 to 14 0 ]
Water and functional additives shown in Tables 3 to 33 (inorganic salts, surface activity) so that each concentration of the cellulose fibers S1 to S3, H1 and H2 has the ratios shown in Tables 3 to 33 below. Additives, oils, moisturizers, preservatives, inorganic fine particles, organic fine particles, organic solvents, fragrances / deodorants) are added at the ratios shown in the table to make a slurry, and a rotational speed of 8,000 rpm using a disper mixer Each sample was obtained by performing a micronization process for 10 minutes. In Tables 3 to 33, the remaining amount excluding the addition amount of the cellulose fiber and the functional additive is the addition amount of water (hereinafter the same).

[Conventional Examples 1-27]
Cellulose fibers obtained according to the method described in WO99 / 28350 were used. That is, a wood valve having a polymerization degree of 760 obtained by cutting the valve seat into 5 mm × 5 mm chips was dissolved in a 65% sulfuric acid aqueous solution at −5 ° C. for 10 minutes under a stirring condition of 150 rpm so that the cellulose concentration was 5%. A transparent and uniform cellulose dope was obtained. The cellulose dope was poured into water (5 ° C.) 2.5 times by weight with stirring, and the cellulose was aggregated in a floc form to obtain a suspension. This suspension is hydrolyzed at 85 ° C. for 20 minutes, and then sufficiently washed with water and filtered until the pH of the washing liquid becomes 4 or more, and the cellulose is a white and transparent gelatinous substance having a cellulose concentration of 15%. Fiber was obtained. This gel-like product was mixed and homogenized for 3 minutes with a household food processor (knife cutter), and further water and functional additives ([inorganic salts] NaCl, KCl, CaCl ₂ , _{MgCl 2, (NH 4) 2} SO 4, Na 2 CO 3, [surfactant] activators 1-3, [oils] oils 1-3, [organic solvent] the organic solvent 1,2) of the table In addition, the cellulose was diluted to a cellulose concentration of 1.5% and mixed for 5 minutes with a blender at a rotation speed of 15,000 rpm. Next, the diluted sample was subjected to a micronization treatment four times with an ultra-high pressure homogenizer (manufactured by Mizuho Kogyo Co., Ltd., Microfluidizer M-110EH, operating pressure 1,750 kg / cm ² ) to obtain a sample. The refined cellulose fiber (A1) obtained by treating the sample (Blank) added only with water four times had an average particle diameter of 0.18 μm and a transmittance of the dispersion of 95%.

[Conventional examples 28 to 51]
Water and functional additives ([inorganic salts] NaCl, KCl, CaCl ₂ , MgCl ₂ , (NH ₄ ) ₂ SO ₄ , Na ₂ CO ₃ , [surfactant] activity shown in Table 36 below in a disper type mixer 97.5 g of an aqueous solution or an aqueous dispersion in which the agent 3, [oils] oils 1 to 3 and [inorganic fine particles] inorganic fine particles 1 and 2 are finally blended to have a predetermined concentration shown in the table, While stirring at a rotational speed of 8,000 rpm using a Disper type stirrer, 0.50 g of carboxyvinyl polymer A2 (manufactured by BF Goodrich, Carbopol 980) was gradually added and dispersed. Thereto, 2.0 g of a 10% aqueous sodium hydroxide solution was added dropwise to carry out neutralization and thickening. A sample was prepared by stirring for 10 minutes to achieve sufficient homogenization. In addition, the viscosity of the sample (Blank) produced only with water and the carboxyvinyl polymer A2 was 61.0 Pa · s.

  The functional additives shown in Tables 3 to 36 below are as follows.

[Inorganic salts]
_{NaCl, KCl, CaCl 2, MgCl} 2, (NH 4) 2 SO 4, Na 2 CO 3

[Surfactant]
Polyoxyethylene lauryl ether (Activator 1)
Alkyl polyglucoside (active agent 2)
Polyoxyethylene lauryl ether sodium sulfate (activator 3)

[Oil]
Dimethylpolysiloxane (oils 1)
Glyceryl triisooctanoate (oils 2)
Squalane (oils 3)

[Humectant]
Glycerin

〔Preservative〕
Methyl paraben

[Inorganic fine particles]
Titanium oxide (inorganic fine particles 1)
Bengala (Inorganic fine particles 2)

[Organic fine particles]
Urethane emulsion (Daiichi Kogyo Seiyaku Co., Ltd., Superflex 150)

[Organic solvent]
Ethanol (organic solvent 1)
Isopropanol (organic solvent 2)

[Perfume and deodorant]
D limonene (fragrance / deodorant 1)
Orange oil (fragrance / deodorant 2)

  Using each sample (composition) thus obtained, each characteristic was evaluated according to the same criteria as described above. These results are also shown in Tables 3 to 36 above.

  From the results of Tables 3 to 36 above, cellulose fibers S1 to S3 having an aldehyde group amount of 0.08 to 0.3 mmol / g and a carboxyl group amount of 0.6 to 2.0 mmol / g were used. Example products having a cellulose fiber content of 0.3 to 5.0% by weight had a small decrease in viscosity and maintained a gel state even when various functional additives (inorganic salts and the like) were added. In the conventional product, when various functional additives were added, the viscosity was greatly reduced, and the separation or gel state could not be maintained.

  In contrast, cellulose fibers S1 to S3 having an aldehyde group amount of 0.08 to 0.3 mmol / g and a carboxyl group amount of 0.6 to 2.0 mmol / g are used. The comparative product having a content of less than the lower limit (0.3% by weight) could not maintain a gel state after 1 day. In addition, cellulose fibers S1 to S3 having an aldehyde group amount of 0.08 to 0.3 mmol / g and a carboxyl group amount of 0.6 to 2.0 mmol / g are used. The comparative product exceeding the upper limit (5.0% by weight) could not obtain a macroscopically homogeneous gel composition.

  Further, in the comparative product using the cellulose fiber H1 having a carboxyl group amount of less than 0.6 mmol / g, the cellulose fiber partially separated and settled, resulting in a macro-uniform gel. The comparative product using cellulose fiber H2 having a carboxyl group amount exceeding 2.0 mmol / g was fluid with time, and could not maintain a gel state after 2 days.

  The gel composition of the present invention uses cellulose fiber, which is a natural material, as a gelling agent and is rich in compounding properties with various functional additives. It can be used widely and suitably as such a toiletry article base material.

Claims (2)

The gel composition comprising the following components (A) to ( C ), wherein the content of the component (A) is in the range of 0.3 to 5.0% by weight of the entire gel composition. A gel-like composition characterized by the above.
(A) A cellulose fiber having a maximum fiber diameter of 1000 nm or less and a number average fiber diameter of 2 to 150 nm, the cellulose having a cellulose I-type crystal structure and a hydroxyl group at the C6 position of the glucose unit in the cellulose molecule Is a cellulose fiber which is selectively oxidized to be modified into an aldehyde group and a carboxyl group, and has 0.08 to 0.3 mmol / g of the aldehyde group and 0.6 to 2.0 mmol / g of the carboxyl group.
(B) Water.
(C) At least one functional additive selected from the group consisting of inorganic salts, surfactants, oils, humectants, preservatives, organic fine particles, inorganic fine particles, deodorants, perfumes and organic solvents. Component (A) of the cellulose fibers, N- presence of oxyl compound, using a co-oxidizing agent, according to claim 1 Symbol placement in which the oxidized part of the hydroxyl groups of cellulose fibers into a carboxyl group and an aldehyde group A gel composition.