JP5733761B2 - Resin composition, film forming agent containing the same, and film - Google Patents

Description

  The present invention relates to a resin composition containing cellulose fibers, a film forming agent containing the resin composition, and a film made of the film forming agent.

  There are many products in the form of emulsions of natural resins and synthetic resins, such as paints, adhesives, waxes, etc., in the product group containing resins. Conventionally, in resin compositions used for such products, those containing cellulose or cellulose derivatives are known as rheology control agents (see Patent Documents 1 and 2).

JP 2004-67719 A JP 2006-111699 A

  However, when the viscosity of the coating material and the like is increased by including the cellulose material in the resin composition as described above, an effect of preventing dripping at the time of coating can be obtained. Since the elongation of the liquid is deteriorated, it becomes difficult to uniformly and uniformly apply, and as a result, the coatability may be lowered.

  In addition, the film obtained by drying the coated film has higher solvent resistance, higher elasticity, antistatic properties, strength improvement such as breaking stress and elongation rate, and coloring during film formation. Suppression etc. are required.

The present invention has been made in view of such circumstances, and is a resin composition used for adhesives, paints or waxes, which has a high initial viscosity and a high viscosity retention after long-term storage. It is an object of the present invention to provide a resin composition capable of forming a high-strength film having excellent properties, solvent resistance, high elasticity, antistatic properties, and the like, a film-forming agent containing the resin composition, and a film.

In order to achieve the above object, the present invention is a resin composition used for an adhesive, paint or wax, comprising the following components (A) and (B) , content of minute, a first aspect the scope der Ru resin composition of 0.1 to 10 parts by weight per 100 parts by weight of the solid content of the component (a).
(A) Resin emulsion.
(B) Cellulose fibers having a number average fiber diameter of 2 to 150 nm, the cellulose having a cellulose I-type crystal structure, and the hydroxyl group at the C6 position of each glucose unit in the cellulose molecule is selectively oxidized and modified. Aldehyde group, ketone group and carboxyl group, and part or all of the aldehyde group and ketone group are reduced, and the carboxyl group content is 1.2 to 2.5 mmol / g , Cellulose fiber, in which the total content of aldehyde groups and ketone groups as measured by the semicarbazide method is 0.3 mmol / g or less, and detection of aldehyde groups by a failing reagent is not observed .

  Moreover, this invention makes the film forming agent containing the resin composition of said 1st summary the 2nd summary.

  Moreover, this invention makes the film | membrane which consists of a film formation agent of said 2nd summary the 3rd summary.

That is, the present inventors are resin compositions used for adhesives, paints or waxes, which have a high initial viscosity, a high viscosity retention after long-term storage , and excellent coating properties and solvent resistance. In order to obtain a resin composition capable of forming a high-strength film having high elasticity, antistatic properties, etc., intensive research was repeated. In the course of the research, it is a cellulose fiber having a number average fiber diameter of 2 to 150 nm, and the cellulose 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. It was recalled that modified fine cellulose fibers were blended with a resin emulsion. Then, the cellulose fiber is prepared by the oxidative modification so that the carboxyl group content is 1.2 to 2.5 mmol / g, and further, by reduction, the total of aldehyde groups and ketone groups as measured by the semicarbazide method It has been found that the intended purpose can be achieved by adding a specific amount of the aldehyde group in such a manner that the content is 0.3 mmol / g or less and the detection of the aldehyde group by the failing reagent is not recognized. The invention has been reached.

  Thus, the resin composition of the present invention is a cellulose fiber having a number average fiber diameter of 2 to 150 nm, and the cellulose has a cellulose I-type crystal structure, and the C6 position of each glucose unit in the cellulose molecule. A special cellulose fiber having a hydroxyl group content in the range of 1.2 to 2.5 mmol / g, which is selectively oxidized and modified to become one of an aldehyde group, a ketone group and a carboxyl group. B) is contained together with the resin emulsion (A). Therefore, when dispersed in a solvent, the resin composition of the present invention exhibits a high viscosity in a stationary state, but the viscosity decreases when a shearing force is applied, so that uniform coating is possible and at the time of coating High dripping prevention effect. Furthermore, since there is little decrease in viscosity during storage, storage stability is excellent, and deterioration of coating properties over time is also eliminated. In addition, a high-strength film having solvent resistance, high elasticity, antistatic properties and the like can be formed from the resin composition of the present invention. And the resin composition of this invention is applicable as an adhesive agent, a coating material, wax, or those manufacturing raw materials. Therefore, it can be used as a water-based paint, adhesive, etc. in various fields such as architecture, automobiles, electronic parts, and printing.

In particular, that the above total content of aldehyde groups and ketone groups of the cellulose fibers (B) is, it der below 0.3 mmol / g as measured by the semicarbazide method, but not found the detection of aldehyde groups by Fehling reagent Therefore , the initial viscosity is high, the viscosity retention rate after long-term storage is high, and further , no coloring occurs during film formation, and a more excellent film can be formed.

The content of solids of the cellulose fibers (B) is, since it is a specific range with respect to 100 parts by weight of the solid content of the resin emulsion (A), it becomes more excellent coating properties, and, A higher-strength film can be formed.

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

The resin composition of the present invention is a resin composition used for adhesives, paints or waxes, and contains a resin emulsion (component A) and specific cellulose fibers (component B). The solid content is set within a specific range .

  The resin emulsion (component A) is an aqueous emulsion or aqueous latex of natural resin or synthetic resin. These may be used alone or in combination of two or more.

  As the aqueous emulsion of the synthetic resin, vinyl acetate-based, urethane-based, acrylic-based, polyester-based, epoxy-based, and polyvinyl alcohol-based resin emulsions are used. Specifically, vinyl acetate resin emulsion, urethane resin emulsion, acrylic resin emulsion, styrene / acrylic copolymer resin emulsion, ethylene, vinyl acid vinyl ester, ethylenically unsaturated carboxylic acid, vinyl chloride, alkyl (meth) acrylate Examples thereof include vinyl acetate copolymer resin emulsions obtained by copolymerizing esters and vinyl acetate. These may be used alone or in combination of two or more.

  Examples of the aqueous latex of the synthetic resin include butadiene latex, chloroprene latex, isoprene latex, copolymer resin latex obtained by copolymerizing butadiene, isoprene, and the like with styrene, acrylonitrile, and the like. These may be used alone or in combination of two or more.

  The solid content concentration (resin amount or rubber amount) of the resin emulsion (component A) with respect to the entire resin composition of the present invention is 0.1 to 70% by weight of the entire resin composition from the viewpoint of coating properties and the like. The range is preferably 10 to 50% by weight.

As said specific cellulose fiber (B component) mix | blended with the said resin emulsion (A component), a number average fiber diameter is 2-150 nm cellulose fiber, Comprising: The cellulose has a cellulose I type crystal structure. And the hydroxyl group at the C6 position of each glucose unit in the cellulose molecule is selectively oxidized and modified to become one of an aldehyde group, a ketone group and a carboxyl group, and part or all of the aldehyde group and ketone group Is reduced, the carboxyl group content is 1.2 to 2.5 mmol / g, the total content of aldehyde groups and ketone groups is 0.3 mmol / g or less as measured by the semicarbazide method, Fine cellulose fibers that are not detected are used. The cellulose fiber is a fiber obtained by subjecting a naturally-derived cellulose solid raw material having an I-type crystal structure to surface oxidation and refinement. That is, in the process of biosynthesis of natural cellulose, nanofibers called microfibrils are first formed almost without exception, and these form multiple bundles to form a higher-order solid structure. In order to weaken the hydrogen bond between the surfaces that are the driving force of the cation, a part of its hydroxyl group (the C6 hydroxyl group of each glucose unit in the cellulose molecule) is oxidized and converted into a carboxyl group, an aldehyde group, or a ketone group. ing.

  Here, the cellulose constituting the specific cellulose fiber (component B) has an I-type crystal structure. For example, in a diffraction profile obtained by wide-angle X-ray diffraction image measurement, 2 theta is around 14 to 17 °. 2 theta can be identified from having typical peaks at two positions near 22 to 23 °.

  The number average fiber diameter of the specific cellulose fiber (component B) is 2 to 150 nm, and from the viewpoint of dispersion stability, the number average fiber diameter is preferably 2 to 100 nm, and particularly preferably 3 to 80 nm. It is. That is, when the number average fiber diameter is less than the above range, it is essentially dissolved in the dispersion medium. Conversely, when the number average fiber diameter exceeds the above range, the cellulose fibers are precipitated, and the cellulose fibers It is because the functionality by blending cannot be expressed. The maximum fiber diameter of the cellulose fiber is preferably 1000 nm or less, and particularly preferably 500 nm or less. That is, when the maximum fiber diameter of the cellulose fiber exceeds the above range, the cellulose fiber is settled, and the functionality due to blending the cellulose fiber cannot be expressed.

  The number average fiber diameter and the maximum fiber diameter of the specific cellulose fiber (component B) can be measured, 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 a big fiber diameter 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.

  The specific cellulose fiber (component B) is one in which the hydroxyl group at the C6 position of each glucose unit in the cellulose molecule is selectively oxidized and modified to become one of an aldehyde group, a ketone group, and a carboxyl group, The carboxyl group content is 1.2 to 2.5 mmol / g. The carboxyl group content is preferably in the range of 1.5 to 2.0 mmol / g. Thus, by setting the content of the carboxyl group within a specific range, in the resin composition of the present invention, while ensuring the coatability, the film has a higher solvent resistance, higher elasticity than conventional, Antistatic properties, strength, etc. can be imparted. If the amount of the carboxyl group is less than the above range, the effects of the present invention as described above may not be sufficiently obtained, and the cellulose fibers may be precipitated. Conversely, the amount of the carboxyl group is within the above range. When it exceeds, water solubility may become too strong.

  The measurement of the carboxyl group amount of the specific cellulose fiber (component B) is, for example, preparing 60 ml of a 0.5 to 1 wt% slurry from a cellulose sample accurately weighed on the dry weight, and adjusting the pH with a 0.1 M aqueous hydrochloric acid solution. After adjusting to about 2.5, 0.05M sodium hydroxide aqueous solution is dropped and the electrical conductivity is measured. The measurement is continued until the pH is about 11. The amount of carboxyl groups 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 formula (1).

  Amount of carboxyl group (mmol / g) = V (ml) × [0.05 / cellulose weight] (1)

  In addition, adjustment of a carboxyl group amount can be performed by controlling the addition amount and reaction time of the co-oxidant used at the oxidation process of a cellulose fiber so that it may mention later.

Moreover, the specific cellulose fibers (B component), after the oxide-modified, Ru was reduced by a reducing agent. As a result, part or all of the aldehyde group and the ketone group are reduced to return to the hydroxyl group. Note that the carboxyl group is not reduced. And by the said reduction | restoration, the total content of the aldehyde group and the ketone group by the measurement by the semicarbazide method of the said specific cellulose fiber (B component) shall be 0.3 mmol / g or less , Preferably it is 0-0.1 mmol / and g range, more preferably shall be the substantially 0 mmol / g. As a result, the viscosity and dispersion stability are increased compared to those obtained by simply oxidative modification, and the dispersion stability is excellent over a long period of time regardless of the temperature. Further, as described above, the cellulose fiber having a total content of aldehyde groups and ketone groups as measured by the semicarbazide method of 0.3 mmol / g or less is used as the cellulose fiber of the component (B) in the resin composition of the present invention. When used, coloring during film formation does not occur and a more excellent film can be formed. In addition, when the sum total of an aldehyde group and a ketone group exceeds 0.3 mmol / g, there exists a possibility that coloring at the time of film formation and the viscosity of a resin composition may fall remarkably with progress of time.

And the specific cellulose fiber (component B) is oxidized using a co-oxidant in the presence of an N-oxyl compound such as 2,2,6,6-tetramethylpiperidine (TEMPO), When the aldehyde group and ketone group generated by the oxidation reaction are reduced by a reducing agent, the specific cellulose fiber can be easily obtained, and a better result is obtained as a resin composition. This is preferable because it can be obtained. Also, reduction with the reducing agent, the is by hydrogenation sodium borohydride (NaBH _4), from the viewpoint, more preferable.

  Incidentally, measurement of the total content of aldehyde groups and ketone groups by the semicarbazide method is performed, for example, as follows. That is, first, 50 ml of a semicarbazide hydrochloride 3 g / l aqueous solution adjusted to pH = 5 with a phosphate buffer is added to a dried sample, sealed, and shaken for 2 days. Next, 10 ml of this solution is accurately collected in a 100 ml beaker, 25 ml of 5N sulfuric acid and 5 ml of 0.05N potassium iodate aqueous solution are added and stirred for 10 minutes. Thereafter, 10 ml of a 5% potassium iodide aqueous solution was added, and immediately titrated with a 0.1N sodium thiosulfate solution using an automatic titrator. From the titration amount and the like, according to the following formula (2), The amount of carbonyl groups (total content of aldehyde groups and ketone groups) can be determined. Semicarbazide reacts with an aldehyde group or a ketone group to form a Schiff base (imine), but does not react with a carboxyl group. Therefore, it is considered that only the aldehyde group and the ketone group can be quantified by the above measurement.

Carbonyl group amount (mmol / g) = (D−B) × f × [0.125 / w] (2)
D: Sample titration (ml)
B: Titrate of blank test (ml)
f: Factor (-) of 0.1N sodium thiosulfate solution
w: Sample amount (g)

In the specific cellulose fiber (B component) in the present invention, only the hydroxyl group at the C6 position of each glucose unit in the cellulose molecule on the fiber surface is selectively oxidized and denatured, and any of aldehyde group, ketone group and carboxyl group It has become. Whether or not only the hydroxyl group at the C6 position of the glucose unit on the surface of the cellulose fiber is selectively oxidized can be confirmed by, for example, a ¹³ C-NMR chart. That is, a 62 ppm peak corresponding to the C6 position of the primary hydroxyl group of the glucose unit, which can be confirmed by a ¹³ C-NMR chart of cellulose before oxidation, disappears after the oxidation reaction, and instead a peak derived from a carboxyl group or the like (178 ppm) The peak of is a peak derived from a carboxyl group). In this way, it can be confirmed that only the C6 hydroxyl group of the glucose unit is oxidized to a carboxyl group or the like.

The detection of the aldehyde group in the specific cellulose fibers (B component), Ru row cracking by full Eringu reagent. That is, for example, after adding a Fering reagent (a mixed solution of sodium potassium tartrate and sodium hydroxide and an aqueous solution of copper sulfate pentahydrate) to a dried sample, the supernatant is obtained when heated at 80 ° C. for 1 hour. When blue and cellulose fiber parts are amber, it can be determined that the aldehyde group has not been detected, and when the supernatant is yellow and the cellulose fiber part is red, it can be determined that the aldehyde group has been detected. .

  The specific cellulose fiber (component B) is obtained, for example, by performing (1) an oxidation reaction step, (2) a reduction step, (3) a purification step, (4) a dispersion step (a refinement treatment step), etc. Can do. 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 cooxidant 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 based on the weight of the reaction aqueous solution, but the reaction concentration can be increased by using a device 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 groups and the like, 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) Reduction step The specific cellulose fiber (component B) is preferably further subjected to a reduction reaction after the oxidation reaction. Specifically, fine oxidized cellulose after the oxidation reaction is dispersed in purified water, the pH of the aqueous dispersion is adjusted to about 10, and the reduction reaction is performed with various reducing agents. As the reducing agent used in the present invention, a general reducing agent can be used, and preferred examples include LiBH ₄ , NaBH ₃ CN, and NaBH ₄ . Among these, NaBH ₄ is particularly preferable from the viewpoint of cost and availability.

  The amount of reducing agent is preferably in the range of 0.1 to 4% by weight, particularly preferably in the range of 1 to 3% by weight, based on finely oxidized cellulose. The reaction is carried out at room temperature or slightly higher than room temperature for 10 minutes to 10 hours, preferably 30 minutes to 2 hours.

  After completion of the above reaction, the pH of the reaction mixture is adjusted to about 2 with various acids, and solid-liquid separation is performed with a centrifuge while sprinkling purified water to obtain cake-like fine oxidized cellulose. Solid-liquid separation is performed until the electric conductivity of the filtrate is 5 mS / m or less.

(3) 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.

(4) 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 (B component) can be obtained by drying the dispersion of the cellulose fiber. It should be noted that the cellulose fiber dispersion may be used in the resin composition in a dispersion state without drying.

  For the dispersion medium of the specific cellulose fiber (component B) obtained as described above, water or a mixed solution of water and an organic solvent is used.

  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 resin 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.

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

The blending amount of the specific cellulose fiber (component B) in the resin composition of the present invention is more excellent in coating properties and can form a higher strength film. the content of solids, and the solid content 100 parts by weight of the resin emulsion (a component) 0. Ru is set in a range of 1 to 10 parts by weight.

  The resin composition of the present invention includes a resin emulsion (component A) and the specific cellulose fiber (component B), and, if necessary, water, an organic solvent, an antioxidant within a range that does not impair the effects of the present invention. , Metal deactivators, flame retardants, plasticizers, flame retardant aids, weather resistance improvers, slip agents, inorganic fillers, organic fillers, reinforcing agents, various colorants, mold release agents, etc. it can. In addition, these are used individually or in combination of 2 or more types.

  Here, preparation of the resin composition of this invention mix | blends resin emulsion (A component), the said specific cellulose fiber (B component), for example, and also mix | blends other materials as needed, Then, these are mixed. It is carried out by mixing treatment.

  Examples of the mixing treatment include various kneaders such as vacuum homomixers, dispersers, propeller mixers, kneaders, blenders, homogenizers, ultrasonic homogenizers, colloid mills, pebble mills, bead mill grinders, high-pressure homogenizers (such as ultra-high pressure homogenizers), Etc. are mixed.

<Film-forming agent and film>
The film-forming agent of the present invention contains the resin composition prepared as described above, and has high solvent resistance, high elasticity, antistatic properties, etc. by applying and spraying the object to be treated and then drying. A strong film can be formed. As described above, when the dry film has the above-described characteristics, the film itself is not easily destroyed, and thus the film is difficult to be peeled off from the object to be processed. Therefore, film-forming agent of the present invention, adhesives, paints, waxes (floor, polish or polishes such as furniture) and used by, other, it can also be used as their raw material. Further, the film (film) itself obtained from the film forming agent can be used alone for a desired application.

  The viscosity of the film forming agent of the present invention in a 25 ° C. environment measured by a BM type rotational viscometer (30 rpm) is preferably in the range of 100 to 50000 mPa · s, particularly from the viewpoint of coating properties and the like. Preferably it is the range of 500-30000 mPa * s.

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

First, reference examples, prior to the Examples and Comparative Examples, the cellulose fibers T1~T3 for reference example, cellulose fibers H1, H2 for cellulosic fibers T 4 to T6 and Comparative Example for Example, the following production examples 1 Made according to ~ 8.

[Production Example 1: Production of Cellulose Fiber T1 (for Reference Example)]
First, 150 ml of water, 0.25 g of sodium bromide, and 0.025 g of TEMPO were added to 2 g of softwood pulp, and the mixture was sufficiently stirred and dispersed. Then, a 13 wt% sodium hypochlorite aqueous solution (co-oxidant) ) Was added to 1.0 g of the above pulp so that the amount of sodium hypochlorite was 5.2 mmol / g, and the reaction was started. Since the pH decreased with the progress of the reaction, the reaction was continued until no change in pH was observed while dropping a 0.5N aqueous sodium hydroxide solution so that the pH was maintained at 10-11 (reaction time: 120 minutes). ). After completion of the reaction, 0.1N hydrochloric acid was added for neutralization, followed by purification by repeated filtration and washing to obtain cellulose fibers having oxidized fiber surfaces. Next, pure water was added to the cellulose fiber to dilute it to 1%, and it was treated once at a pressure of 100 MPa using a high-pressure homogenizer (H11, manufactured by Sanwa Engineering Co., Ltd.). The obtained cellulose fiber T1 had a number average fiber diameter of 89 nm, a carboxyl group amount of 1.2 mmol / g, and a crystal structure.

[Production Example 2: Production of Cellulose Fiber T2 (for Reference Example)]
Cellulose fiber T2 was produced in the same manner as in Production Example 1 except that the sodium hypochlorite aqueous solution to be added was adjusted to a sodium hypochlorite amount of 6.5 mmol / g with respect to 1.0 g of the pulp. The obtained cellulose fiber T2 had a number average fiber diameter of 54 nm, a carboxyl group amount of 1.6 mmol / g, and a crystal structure.

[Production Example 3: Production of Cellulose Fiber T3 (for Reference Example)]
Cellulose fiber T3 was produced according to Production Example 1, except that the sodium hypochlorite aqueous solution to be added was 12.0 mmol / g in amount of sodium hypochlorite with respect to 1.0 g of the pulp. The obtained cellulose fiber T3 had a number average fiber diameter of 11 nm, a carboxyl group amount of 2.0 mmol / g, and a crystal structure.

[Production Example 4: Production of Cellulose Fiber T4 (for Examples)]
After coniferous pulp was oxidized by the same method as in Production Example 1, it was subjected to solid-liquid separation with a centrifuge, and pure water was added to adjust the solid content concentration to 4%. Thereafter, the pH of the slurry was adjusted to 10 with a 24% NaOH aqueous solution. The slurry was reduced to 30 ° C. by adding 0.2 mmol / g of sodium borohydride to the cellulose fiber and reacting for 2 hours. After the reaction, 0.1N hydrochloric acid was added for neutralization, followed by purification by repeated filtration and washing to obtain cellulose fibers. Next, pure water was added to the cellulose fiber to dilute it to 1%, and it was treated once at a pressure of 100 MPa using a high-pressure homogenizer (H11, manufactured by Sanwa Engineering Co., Ltd.). The obtained cellulose fiber T4 had a number average fiber diameter of 58 nm, a carboxyl group amount of 1.2 mmol / g, and a crystal structure.

[Production Example 5: Production of cellulose fiber T5 (for Examples)]
The softwood pulp was oxidized by the same method as in Production Example 2, and then reduced and purified by the same method as in Production Example 4. Next, pure water was added to the cellulose fiber to dilute it to 1%, and it was treated once at a pressure of 100 MPa using a high-pressure homogenizer (H11, manufactured by Sanwa Engineering Co., Ltd.). The obtained cellulose fiber T5 had a number average fiber diameter of 23 nm, a carboxyl group amount of 1.6 mmol / g, and had a crystal structure.

[Production Example 6: Production of cellulose fiber T6 (for Examples)]
After coniferous pulp was oxidized by the same method as in Production Example 3, it was reduced and purified by the same method as in Production Example 4. Next, pure water was added to the cellulose fiber to dilute it to 1%, and it was treated once at a pressure of 100 MPa using a high-pressure homogenizer (H11, manufactured by Sanwa Engineering Co., Ltd.). The obtained cellulose fiber T6 had a number average fiber diameter of 4 nm, a carboxyl group amount of 2.0 mmol / g, and a crystal structure.

[Production Example 7: Production of cellulose fiber H1 (for comparative example)]
Cellulose fiber H1 was produced in accordance with Production Example 1 except that the sodium hypochlorite aqueous solution to be added had a sodium hypochlorite amount of 4.1 mmol / g with respect to 1.0 g of the pulp. The obtained cellulose fiber H1 had a number average fiber diameter of 182 nm, a carboxyl group amount of 1.0 mmol / g, and had a crystal structure.

[Production Example 8: Production of cellulose fiber H2 (for comparative example)]
Production example except that regenerated cellulose is used instead of conifer pulp and the sodium hypochlorite aqueous solution added is 27.0 mmol / g of sodium hypochlorite with respect to 1.0 g of regenerated cellulose. According to No. 1, cellulose fiber H2 was produced. The obtained cellulose fiber H2 had a number average fiber diameter of not measurable (1 nm or less), a carboxyl group amount of 3.1 mmol / g, and had no crystal structure.

  In addition, the measurement of each item regarding the cellulose fibers T1-T6, H1, and H2 shown in the said Table 1 was performed according to the following reference | standard.

〔Crystal structure〕
Using an X-ray diffractometer (Rigaku Corporation, RINT-Utima3), the diffraction profile of cellulose fiber was measured, and typical at two positions, 2 theta = 14-17 ° and 2 theta = 22-23 °. When a typical peak was observed, the crystal structure (type I crystal structure) was evaluated as “present”, and when no peak was observed, it was evaluated as “none”.

[Number average fiber diameter]
The number average fiber diameter of the cellulose fibers was observed using a transmission electron microscope (TEM) (manufactured by JEOL Ltd., JEM-1400). That is, after each cellulose fiber was cast on a hydrophilized carbon film-coated grid and negatively stained with 2% uranyl acetate, the number average fiber diameter was determined according to the method described above. Was calculated.

[Measurement of carboxyl group content]
After preparing 60 ml of a cellulose aqueous dispersion in which 0.25 g of cellulose fiber was dispersed in water, the pH was adjusted to about 2.5 with 0.1 M hydrochloric acid aqueous solution, and 0.05 M sodium hydroxide aqueous solution was added dropwise. Electrical conductivity measurements were made. The measurement was continued until the pH was about 11. The amount of carboxyl groups was determined from the amount of sodium hydroxide consumed in the neutralization step of the weak acid (V) where the change in electrical conductivity was slow, according to the following formula (1).

  Amount of carboxyl groups (mmol / g) = V (ml) × [0.05 / cellulose weight] (1)

[Measurement of amount of carbonyl group (semicarbazide method)]
About 0.2 g of cellulose fiber was precisely weighed, and precisely 50 ml of a 3 g / l aqueous solution of semicarbazide hydrochloride adjusted to pH = 5 with a phosphate buffer was added thereto, sealed, and shaken for 2 days. Then, 10 ml of this solution was accurately collected in a 100 ml beaker, 25 ml of 5N sulfuric acid and 5 ml of 0.05N potassium iodate aqueous solution were added, and the mixture was stirred for 10 minutes. Thereafter, 10 ml of a 5% potassium iodide aqueous solution was added, and immediately titrated with a 0.1N sodium thiosulfate solution using an automatic titrator. From the titration amount and the like, according to the following formula (2), The amount of carbonyl groups (total content of aldehyde groups and ketone groups) was determined.

Carbonyl group amount (mmol / g) = (D−B) × f × [0.125 / w] (2)
D: Sample titration (ml)
B: Titrate of blank test (ml)
f: Factor (-) of 0.1N sodium thiosulfate solution
w: Sample amount (g)

[Detection of aldehyde group]
0.4 g of cellulose fiber was precisely weighed and added with a Fering reagent prepared according to the Japanese Pharmacopoeia (5 ml of a mixed solution of sodium potassium tartrate and sodium hydroxide and 5 ml of an aqueous copper sulfate pentahydrate solution) at 80 ° C. Heated for 1 hour. And when the supernatant was blue and the cellulose fiber part was amber, it was judged that no aldehyde group was detected, and was evaluated as “none”. Moreover, when the supernatant was yellow and the cellulose fiber part was red, it was judged that an aldehyde group was detected, and was evaluated as “present”.

[ Reference Example 1]
4 g of cellulose fiber T1 prepared in Production Example 1 (solid content: 0.04 g) and 100 g of urethane emulsion (Superflex 460, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (solid content: 40 g) are mixed, and a homodisper is used. Stir for 3 minutes at 3000 rpm. After measuring the initial viscosity of the resin composition thus obtained, a part was transferred to a heat-resistant bottle and stored in a constant temperature bath at 40 ° C., and the viscosity retention after 7 days and 30 days was measured. (Resin composition physical properties).

  Furthermore, 5 g of this composition was cast in a 10 × 15 cm plastic container as a solid content, and heated and dried in this order for 2 days at room temperature, 6 hours at 80 ° C., and 30 minutes at 120 ° C. The presence or absence of coloring by was confirmed. The obtained film was subjected to mechanical strength measurement, solvent resistance measurement, and antistatic property measurement (film physical properties).

Reference Example 2-9, Example 1-9, Comparative Examples 1-7]
Blended later cellulosic fibers and urethane emulsion in the amounts shown in Table 2 to Table 4, a resin composition was prepared in the same manner as in Reference Example 1, the initial viscosity in the same manner as in Reference Example 1, the viscosity was measured retention ( Resin composition physical properties). Further, a dry film was prepared in the same manner as in Reference Example 1, the presence or absence of coloring was confirmed, and the film was subjected to mechanical strength measurement, solvent resistance measurement, and antistatic property measurement (film physical properties).

Incidentally, Reference Example 1-9, Example 1-9, in Comparative Examples 1-7, measurement and evaluation of each property, particularly, were performed according to the following criteria. The results are shown in Tables 2 to 4 below.

(Measurement of initial viscosity)
After preparing the resin composition, the mixture was allowed to stand at room temperature for 1 day, and then the viscosity was measured using a B-type viscometer (rotation speed: 60 rpm, measurement time: 3 minutes, measurement temperature: 20 ° C.).

(Measurement of viscosity retention)
After preparing the resin composition, it was transferred to a heat-resistant bottle and allowed to stand in a constant temperature bath at 40 ° C. for 7 and 30 days, and then the viscosity was measured using a B-type viscometer (measured at 60 rpm, measuring time 3 minutes) Temperature 20 ° C.). And the viscosity retention was computed from the measured value and the value of initial viscosity using the following formula | equation.
Viscosity retention [%] = viscosity [mPa · s] after 7 days and 30 days / initial viscosity [mPa · s] × 100

[Confirmation of coloring of dry film]
The resin composition is cast in a plastic container in a solid amount of 5 g, dried at room temperature for 2 days, at 80 ° C. for 6 hours, and at 120 ° C. for 30 minutes to produce a film. It was confirmed.

(Mechanical strength measurement)
The resin composition was cast in a plastic container in a solid amount of 5 g, and dried at room temperature for 2 days, at 80 ° C. for 6 hours, and at 120 ° C. for 30 minutes to prepare a film. The obtained film was cut into 5 × 60 mm, and measured with a tensile tester (RTC-1225A, manufactured by ORIENTEC) under conditions of a moving speed of 5 mm / min, 20 ° C., and 40% RH. The elastic modulus (MPa) was obtained from the strain rate and the initial slope of the stress curve at this time, and the stress at the point where the test piece broke was defined as the breaking stress (MPa).

(Solvent resistance measurement)
The resin composition was cast in a plastic container in a solid amount of 5 g, and dried at room temperature for 2 days, at 80 ° C. for 6 hours, and at 120 ° C. for 30 minutes to prepare a film. The obtained film was cut into 20 × 40 mm, immersed in an ethyl acetate / toluene mixture (weight ratio 1: 1), and allowed to stand at 40 ° C. for 24 hours. And 24 hours later, the test piece was taken out, wiped off the solvent, and the weight and area were measured. From the measured values, the weight increase rate [%] and the area increase rate [%] were calculated with an initial value of 0%.

(Antistatic measurement)
The resin composition was cast in a plastic container in a solid amount of 5 g, and dried at room temperature for 2 days, at 80 ° C. for 6 hours, and at 120 ° C. for 30 minutes to prepare a film. Then, using a super insulation resistance meter (R8340, manufactured by ADVANTEST), the surface resistance value [Ω] at an applied voltage of 500 V, 25 ° C. and 40% RH was measured.

  From the results of the above table, it can be seen that in the examples, the initial viscosity is higher in the resin composition properties than in the comparative examples, and the viscosity decrease with time is small. Further, in the examples, it can be seen that in the physical properties of the film, the mechanical strength is higher than that of the comparative example, and the solvent resistance and antistatic property are also excellent.

In addition, as a result of comparison with the reference example, the example uses cellulose fibers T4 to T6 in which the amount of carbonyl groups is 0.3 mmol / g or less and no aldehyde group is detected, so the initial viscosity is high. Also, the viscosity retention after long-term storage was high, and the film was not colored.

In addition, regarding the cellulose fibers T1 to T6, whether or not only the hydroxyl group at the C6 position of the glucose unit on the cellulose fiber surface was selectively oxidized to a carboxyl group or the like was confirmed by a ¹³ C-NMR chart. That is, the 62 ppm peak corresponding to the C6 position of the primary hydroxyl group of the glucose unit, which can be confirmed on the ¹³ C-NMR chart of cellulose before oxidation, disappears after the oxidation reaction, and instead a peak derived from the carboxyl group at 178 ppm. It was appearing. From this, it was confirmed that the cellulose fibers T1 to T6 were all oxidized only at the C6 hydroxyl group of the glucose unit to an aldehyde group or the like.

Further, the cellulose fiber has a number average fiber diameter of 2 to 150 nm, the cellulose has a cellulose I-type crystal structure, and the hydroxyl group at the C6 position of each glucose unit in the cellulose molecule is selectively oxidized and modified. Aldehyde group, ketone group and carboxyl group, and part or all of the aldehyde group and ketone group are reduced, and the carboxyl group content is 1.2 to 2.5 mmol / g , As long as the total content of aldehyde groups and ketone groups as measured by the semicarbazide method is 0.3 mmol / g or less and no detection of aldehyde groups by a failing reagent is observed , an excellent resin composition as in the examples It was confirmed that physical properties and film properties can be obtained.

  Furthermore, it was confirmed that excellent resin composition properties and film properties can be obtained in the same manner as in Examples even when other aqueous resin emulsions are used in place of urethane emulsions used in Examples. It was.

  The resin composition of the present invention is excellent in coating property and the like and can form a dry film having high strength. Therefore, by utilizing the film forming action, an adhesive, paint, wax, or their It can be applied as a manufacturing raw material. Therefore, it can be used as a water-based paint, adhesive, etc. in various fields such as architecture, automobiles, electronic parts, and printing.

Claims (5)

A resin composition used for adhesives, paints or waxes, comprising the following components (A) and (B) , wherein the solid content of component (B) is the solid content of component (A) resin composition, wherein the range der Rukoto of 0.1 to 10 parts by weight per 100 parts by weight.
(A) Resin emulsion.
(B) Cellulose fibers having a number average fiber diameter of 2 to 150 nm, the cellulose having a cellulose I-type crystal structure, and the hydroxyl group at the C6 position of each glucose unit in the cellulose molecule is selectively oxidized and modified. Aldehyde group, ketone group and carboxyl group, and part or all of the aldehyde group and ketone group are reduced, and the carboxyl group content is 1.2 to 2.5 mmol / g , Cellulose fiber, in which the total content of aldehyde groups and ketone groups as measured by the semicarbazide method is 0.3 mmol / g or less, and detection of aldehyde groups by a failing reagent is not observed . The cellulose fiber of the component (B) is oxidized using a co-oxidant in the presence of an N-oxyl compound, and the aldehyde group and the ketone group generated by the oxidation reaction are reduced by the reducing agent. are, according to claim 1 Symbol placement of the resin composition. The resin composition according to claim 2 , wherein the reduction by the reducing agent is by sodium borohydride. A film forming agent comprising the resin composition according to any one of claims 1 to 3 . A film comprising the film forming agent according to claim 4 .