JPH08209551A - Coloring of fibrous sheet-like product - Google Patents

Abstract

PURPOSE: To stably obtain a sheet of desired color with fastness to water by imparting a fibrous sheet-like product with a cationic direct dye solution followed by treating the resultant product with an anionic substance dispersion containing a water repellent. CONSTITUTION: First, a fibrous sheet-like material comprising fibers or pulped fibers having affinity with direct dye such as cotton linter or kraft pulp is impregnated or coated with an aqueous solution of a cationic direct dye having azo compound residue and cationic group in its molecule and capable of forming an intramolecular or intermolecular salt, and then dried. Subsequently, the resultant sheet-like material is impregnated or coated with a dispersion containing an anionic polymer such as CMC, an anionic substance such as tannic acid or a derivative therefrom, and an anionic or nonionic water repellent such as a fluororesin capable of forming a stable dispersion together with the above compounds, and then dried, thus accomplishing the water-repelling and dye-setting treatment of the resultant color sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coloring a fibrous sheet material, and more particularly to a method for coloring a fibrous sheet material which has a clear color and is easy to manufacture.

[0002]

2. Description of the Related Art As a colored sheet which can be stably obtained in various colors with a sheet suitable for packaging, a paper mainly containing a considerable amount of plant fiber pulp such as wood pulp or a wet non-woven fabric is suitable. ,in use. Since other materials, such as a plastic film, have a high degree of difficulty in coloring, colored products are expensive and are often used colorless. Similar to plastic films, dry non-woven fabrics are difficult to color.

The following methods have been conventionally used for coloring the above-mentioned paper or wet non-woven fabric. A. A method in which a colorant is added in a batch method in a state where plant fiber pulp is dispersed in water (pulp slurry), B. A method of continuously measuring and adding a colorant to a pulp slurry being sent to a sheet forming apparatus; A method of applying a colored size press liquid in a size press unit installed at the rear of a sheet forming apparatus such as a paper machine. Although the coloring agent is a dye, a size-pressing size agent such as starch is usually mixed.

D. In addition, a method in which a dye is supplied by a calender stack for coloring, or a method in which a dry sheet is immersed in a colorant liquid by an independent processing machine.

[0005]

Among the above, the method A has poor flexibility in toning, and a large amount of colored waste paper is generated during color change, and many pipes from raw material adjustment to drainage. The problem is that a large amount of cleaning wastewater is generated due to the pollution of the above.

The method B is considerably improved in the two problems of the method A, but when the frequency of color change is increased, the amount of the remaining colored fine fiber liquid and the washing waste water in the process also becomes large. It becomes a problem. The method C has a drawback that the amount of dye adhering largely varies and the stability of color is poor. Therefore, there is a problem that it is not suitable for fields requiring a high level of beautiful colors. The method using the calendar stock in D has the same problem as C. Moreover, the method of using the calender stock and the method of immersing it in an independent processing machine are A and B.
It is difficult to set a longer time for the dye to penetrate into the sheet as compared with the above method, the water resistance of the obtained coloring is insufficient, and it is difficult to obtain a dyed sheet which is fast against water.

In recent years, cationic direct dyes have emerged as dyes for paper coloring. This dye has high speed dyeing property and high exhaustion property, and is dyed on paper or cotton cloth to have good water fastness and sunlight fastness. As a method of applying it to the colored paper, a method of continuously immersing in the state where the above-mentioned A, B and C methods and the paper making process are completed, squeezing between rolls, and drying is also proposed (JP-A-54-142237). . Even if this dye is used, in the methods A and B, the residual dye in the dissolved state is greatly reduced, but the colored fine fibers are not reduced,
It is discharged along with water from the paper making machine of the paper machine to form colored waste water. Therefore, a large amount of cleaning drainage is required, and the environmental protection cost for collecting the colored fine fibers in the drainage is also high.

The coloring method in which the paper is continuously dipped in the above cationic direct dye solution, squeezed and dried reduces the residual dye and the residual colored fine fibers, and the color change is easy. However, the colored sheet produced by this method has insufficient water fastness, and for example, when cut flowers are packaged, there is a drawback that the coloring agent seeps out due to the moisture of the flower or the moisture of the hand holding the stain. .

The object of the present invention is to solve the above-mentioned problems, and a long continuous colored sheet can be easily manufactured, various colors can be stably obtained, and it can be obtained with respect to water. It is an object of the present invention to provide a method for coloring a fibrous sheet-like product, which is capable of obtaining a robust colored sheet, easily switching colors, and generating an extremely small amount of colored waste water.

[0010]

According to a first aspect of the present invention, a fibrous sheet material is impregnated with a cationic direct dye dispersion or adhered by coating and then impregnated with an anionic substance dispersion. The gist is a method for coloring a fibrous sheet material, which includes a step of applying the fibrous sheet material.

According to a second aspect of the present invention, the fibrous sheet-like material contains fibers or pulped fibers having an affinity for direct dyes. Is the gist.

The invention according to claim 3 is claim 1 or claim 2.
In 1, the anionic substance dispersion liquid is one or two selected from an anionic polymer substance, tannic acid or a derivative thereof.
The gist is that it is more than one species.

A fourth aspect of the present invention is the water repellent agent according to any one of the first to third aspects, wherein the anionic substance dispersion liquid coexists with the anionic substance and the anionic substance to form a stable dispersion liquid. The gist is that it includes.

(Fibrous sheet material) A1. Fibrous In the present invention, fibrous means that it is mainly composed of fibers. The fibers include the following.

Plant Fiber, Plant Fiber Pulp, Regenerated Cellulose Fiber, Synthetic Fiber The plant fiber, plant fiber pulp and regenerated cellulose fiber will be described in detail later. The synthetic fiber referred to in the present invention is
It is a fiber that is negatively charged in neutral water, and has the property of adsorbing a positively charged dissolved dye on its surface. Examples of synthetic fibers include vinylon, nylon, polyester, polyacrylonitrile, polypropylene, polyethylene, other polyolefins, polyurethane, polyvinyl chloride, polyvinylidene chloride, and the like.

(Fibers having a slight affinity for direct dyes) Fibers having a slight affinity for direct dyes are:
The following can be mentioned.

Examples of vegetable fibers include cotton, cotton linter, and hemp (flax, ramie, jute, cannabis) and the like. The plant fiber pulp includes the following.

(A) Wood pulp (softwood, hardwood, and, depending on the method of pulping, there are dissolving pulp, kraft pulp, mechanical pulp, etc., but the amount of lignin remaining should be small.) (B) Mercerized wood Pulp (mercerized product of the above wood pulp) (c) Wood bast pulp (powder, sanpei, ganpi) (d) Herbaceous bast pulp (flax, ramie, kenaf) (e) Leaf fiber pulp (manila hemp, Sisal hemp, banana) (f) Stem culm pulp (straw, bagasse, bamboo, esparto grass) (G) Seed fiber pulp (cotton, cotton linter) Examples of regenerated cellulose fibers include viscose rayon and cupra rayon. You can

Examples of synthetic fibers include vinylon and nylon. B1. Sheet-like material Sheet-like material means paper, wet non-woven fabric, dry non-woven fabric (web forming method by card method or air-laid method, adhesive non-woven fabric, thermal bond non-woven fabric, needle punched non-woven fabric, spunlace, hydroentanglement method or the like. Entangling method), spunbonded nonwoven fabric, meltblown nonwoven fabric, etc., wherein the fibers of A1 are exposed and dyes can be adsorbed in water. Further, spunbonded non-woven fabrics and melt blown non-woven fabrics in which the fibers of A1 are added or compounded can be mentioned. (Cationic direct dye) The term "cationic direct dye" as used in the present invention means that it has an azo compound residue such as mono-azo or dis-azo (or poly-azo) in its molecule and has a cationic group. It is a cationic direct dye capable of forming an aqueous solution by forming an intramolecular salt or an extramolecular salt with.

The cation residue includes a basic group capable of being protonated such as a dialkylaminoalkylene group, and an ionized cationic group such as a trialkylaminoammonium group. The cationic group binds with an acid to form an extramolecular salt, and as an acid bound in this formation, a relatively low molecular weight inorganic acid (hydrochloric acid, sulfuric acid, phosphoric acid, etc.) or an organic acid (formic acid, Acetic acid, lactic acid, etc.) are used. In addition,
Details will be described later.

Those not in the acid / salt form are used as an acidic aqueous solution. As an example disclosed in JP-A-54-142237, the cationic group forms an intramolecular salt as shown in Chemical formula 1, and the basic group which can be protonated is not protonated,
No salt is formed.

[0022]

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(Hue) Bluish red In addition, as shown in Chemical formula 2, in addition to the salt form of the cation group, an outer salt formation due to protonation of the basic group is formed as an acetic acid addition salt. .

[0024]

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(Hue) A bluish red cationic direct dye is an azo compound residue having both (1) color forming property and dyeing property called direct property, to which a sulfonic acid group is bonded. And (2) a cationic group or a basic group capable of being protonated, or both of them.
(3) It is composed of a portion connecting (1) and (2). Dyes having this basic structure are introduced in the following documents.

Japanese Patent Publication No. 63-45425 (hereinafter referred to as Japanese Patent No. 1) Japanese Patent Publication No. 57-53564 (hereinafter referred to as Japanese Patent No. 2) Japanese Patent Publication No. 59-147053 (hereinafter referred to as Japanese Patent No. 3) Japanese Patent Publication No. 59-217762. No. (hereinafter referred to as Japanese Patent No. 4) JP-A-60-130651 (hereinafter referred to as Japanese Patent No. 5) No. 62-41268 (hereinafter referred to as Japanese Patent No. 6) JP-A No. 62-288660 (hereinafter referred to as Japanese Patent No. 7) Japanese Unexamined Patent Publication No. 62-292860 (hereinafter, referred to as Toku 8) Japanese Unexamined Patent Publication No. 2-255867 (hereinafter, referred to as No. 9) Japanese Unexamined Patent Publication No. 2-276867 (hereinafter, referred to as No. 10) Azo compound residue (hereinafter, azo residue) (Abbreviated as 1) to 1 to 4 can be combined. The special features 2 are mono-azo residue, dis-azo residue, tris-azo residue, tetrakis-
A method for implementing an azo residue, a disazoazoxy residue is described.

As the cationic group or the basic group capable of being protonated, various structures of a substituent containing a nitrogen atom have been proposed as described in detail in Special Features 5 and 7. In the case of a cationic group, it has an organic quaternary ammonium salt structure, but as the organic group bonded to the nitrogen atom, an alkyl group, an alkoxyl group, a hydroxyalkyl group, a cyanoalkyl group,
Phenyl group, benzyl group (phenyl group and benzyl group include those having a substituent), (nitrogen-containing) heterocyclic residue (eg, pyridinium, picolinium, pyrrolidinium, morpholium, N-methylmorpholinium, N-methylpyrrole) Peridinium and N-methylpiperazinium).

The basic group capable of being protonated is basically an organic amine structure. Examples of the organic group bonded to the nitrogen atom of the amine include organic groups bonded to the nitrogen atom of the organic quaternary ammonium structure of the cationic group. Also, a hydrogen atom is included.

These cationic groups and basic groups that can be protonated are as shown in Chemical Formula 3 below.

[0030]

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R ₂ is hydrogen or alkyl. Q is alkylene such as ethylene and propylene. R ₃ , R ₄ ,
R ₅ , R ₆ , and R ₇ are organic groups bonded to the above nitrogen atom.

At least one sulfonic acid group is necessary, and 2 to 4 sulfonic acid groups are usually used. This has the effect of directness. The sum of the number of cationic groups and basic groups that can be protonated is important, and it must be at least one more than the sum of the numbers of sulfonic acid and other dissociative anionic groups. As a result, the cationic property of the dye is retained. The anion paired with the cation may be added in the form of an aqueous solution when the dye solution is blended.

When these sulfonic acid-containing basic azo compounds are used as dyes, an excess of cationic group or basic group which does not form an intramolecular salt is usually added to the outside of the molecule with a non-color-forming anion-forming substance. Make salt. Examples include chlorine, bromine, bisulfate, methylsulfate, aminosulfonic acid, perchloric acid, oxalic acid, acetic acid, maleic acid, succinic acid, citric acid and the like. These are described in detail in Special 7.
Other types include free type and metal complex type.

The basic direct dye obtained as described above is used as it is or in the form of a 1: 1 metal complex salt or a 1: 2 metal complex salt. As the metal used for complex chlorination, copper, chromium, cobalt, nickel, and manganese are used according to Special Feature 7. The metal complex can be formed by directly reacting with a required number of moles of the metal salt or by using the action of an oxidant.

Thus, cationic direct dyes of various colors are available. The chemical structures of some of them are shown in the following documents.

[0036]

[Chemical 4]

(Hue) Scarlet Red (Reference) JP-A-59-147053

[0038]

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(Hue) Yellow-Orange (Reference) JP-A-2-276867

[0040]

[Chemical 6]

(Hue) Patina (Reference) JP-A-57-53564

[0042]

[Chemical 7]

(Hue) Marine Blue (Reference) JP-A-59-147053

[0044]

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(Hue) Neutral Bull (blue) (Reference) JP-A-60-130651

[0046]

[Chemical 9]

(Hue) Brown (Reference) JP-A-62-288660 and the structures shown in the above chemical formulas 1 and 2.

These examples include cationic azo compounds of the various structural types mentioned above. (Coloring method) Application of cationic direct dyes to paper coloring is
There has been proposed a method of dyeing a paper raw material slurry before papermaking and a method of dipping a dye solution after papermaking.

When dyeing a paper material in a slurry state,
A method is known in which batch dyeing and continuous mixing of dyes at the seed hole are performed. Further, there is also known a method for producing a size paper and dyeing in which a sizing agent and a fixing agent such as alum are added after dyeing. There are also known methods for dyeing with a size press attached to a paper machine (these methods are described in Special 6 and Special 8).
Furthermore, a coloring method has also been proposed in which unsized paper and sized paper after papermaking are continuously immersed in a dye solution, squeezed with two rolls, and then dried. Note that these methods are described in common in special features 1 to 10. (Impregnation or coating method) Sheet material (hereinafter referred to as sheet)
Unlike knitted fabrics, is often used in long rolls, and therefore the dip dyeing method is not suitable, and the raw material dyeing or continuous dyeing method is suitable. In this method, a sheet is dipped in a dye dispersion liquid and immediately penetrated into the sheet, and a method of removing excess liquid (also referred to as impregnation) and a dye dispersion liquid on the surface of the sheet are preferable. There is a coating method in which a required amount is applied and the inside is permeated in the drying step.

When the fibrous sheet is impregnated with the cationic dye dispersion liquid, the dye concentration in the liquid rapidly decreases due to ionic adsorption, and re-use of the removed excess liquid requires a large concentration adjustment. For the impregnation, there are a method of dipping in a liquid, a spray, a method of applying excessively with a roll and then squeezing with a squeezing roll, a method of scraping off with a bar, and the like. For coating, roll coating,
Alternatively, a spray or fountain coater can be used. (Impregnation, heating after coating) After impregnation or coating, heat drying is suitable for dyeing the dye to the inside of the fine structure of the fiber. For heating, a cylinder dryer equipped with a large number of water-repellent cylinders or a hot air dryer that passes a hot air chamber can be used. Moisture may be completely removed, or if the dyeing is sufficiently advanced, it is not necessary to completely dry after the heating up to that point. The temperature of the hot air is suitably 60 ° C to 120 ° C, but is not particularly limited to these temperatures. (Anionic substance) In order to improve water fastness of a dyed cellulose fiber with a direct dye, a cationic compound has been conventionally used as a fixing agent. Dicyan-based, polyamine-based and polycation-based cationic compounds have been used. The action of these compounds is described as insolubilization on cellulose fibers by reaction with dyes.

The following anionic substances are used in the present invention. (1) Water-soluble or water-dispersible anionic polymer compound For example, carboxymethyl cellulose, acrylic acid polymerized or copolymer, anionic acrylamide copolymer and the like can be mentioned.

(2) Anionic polymer emulsion For example, styrene-butadiene copolymer, methacrylate-butadiene copolymer, polyacrylic acid ester, polyurethane and the like can be mentioned.

(3) Tannic Acid, or Derivatives Thereof, and Synthetic Tannin These anionic substances are selected so as to form a stable liquid even when water is added and necessary dilution is performed. In addition, a low-molecular water-soluble anionic substance such as an organic acid has an adverse effect because it enhances the water solubility of the cationic direct dye, and the anionic substance of (1) and (2) above is acidic and becomes water-soluble. It is preferable to select from those which become insoluble. (Water-repellent agent) The water-repellent agent that forms a stable dispersion liquid together with the anionic substance is a nonionic or anionic water-repellent agent. This has the ability to impart water repellency to the sheet or significantly reduce the water absorption by impregnating or coating the sheet with a single aqueous dispersion. One of the most preferable is a fluororesin-based water-based water repellent. There are non-ionic and anionic types, which are sold as products such as Asahi Guard (trademark, Asahi Glass Co., Ltd.).

Further, a nonionic dispersion liquid of an alkyl ketene dimer or an alkenyl succinic acid is also an example which can be used. It is preferable that these water repellents are colorless, do not discolor when exposed to sunlight or fluorescent light, and do not noticeably change the hue of the cationic direct dye dyed on the sheet. (Method of implementation) Suitable for packaging cut flowers, confectionery, western goods, small items, etc., that is, for use in applications that also have a decorative effect, the sheet material contains a considerable amount of wood pulp due to price restrictions. What you do is better. However, when a sheet made of wood pulp is used in the shape of a funnel like a cut flower, it tends to be wrinkled at an acute angle, and it tends to be difficult to expand the sheet. Because the tactile feel I have with my hands is hard,
This is a little difficult, but this is fine.

However, mercerized wood pulp is preferable to wood pulp for the following reasons. That is, a bulky sheet can be obtained from mercerized wood pulp, and since it is relatively flexible, a funnel-shaped package with an upward spread can be easily formed, and the tactile sensation is also good. On the other hand, in the case of cut flower packaging, water often leaks from the inside,
Furthermore, since it is exposed without holding it in a bag or the like, it is unsuitable if it is torn or significantly deformed even if it gets wet with some rain.
Therefore, it is preferable to have wet strength and shape retention when wet.

It is common to add a wetting co-acting agent to obtain the wet strength, but this alone makes the sheet hard and is not preferable in terms of tactile sensation. In addition, the tear strength may decrease, and for example, tear may occur when rubbed by a sharp object during use.

As a second method for obtaining the wet strength, it is preferable to use synthetic fibers (hereinafter referred to as fusible fibers) having self-adhesiveness by heat fusion or the like. Another advantage of using fusible fibers is that the sheets can be made more bulky unless extreme heat and pressure are applied. In addition, tear strength can be increased as another advantage. For example, polyester in the core,
By using a composite fiber using a low softening point polyester for the sheath, it becomes possible to increase wet strength, bulkiness and tear strength concurrently.

The method of forming the sheet is preferably carried out using a paper machine. This is a method in which raw material fibers are dispersed in water to form a slurry, which is dehydrated to form a sheet by a paper making machine, and dried and heat-sealed. It is also useful to add a small amount of fibrous polyvinyl alcohol as an auxiliary agent of this method to prevent the sheet from deforming before the end of the heat fusion.

Other chemicals for papermaking can also be used appropriately.
Further, it may be effective to use a small amount of the wet strength agent and the heat-fusion fiber in combination. In this case, a polyamidoamine epichlorohydrin type, a polyacrylamide type or the like is used as the wetting aid.

With respect to the weight of the sheet, the value varies from the weight that does not easily break even when it is wet with water to the weight that does not make it difficult to wrap, but depending on the raw fiber and the additive chemical, 20 g / m ^{2 to} 100 g / m ² is suitable. If it is too light, there is a problem in that the retention of the dye solution decreases. The cationic direct dye dispersion liquid (hereinafter referred to as dye liquid) is usually prepared by dispersing with water. The PH is adjusted at PH 4.0 ± 0.5.

The application of the dye solution to the sheet by impregnation or coating is desirable because the dye solution should spread evenly to the inside or the surface of the sheet under the condition that the occurrence of dyeing unevenness is prevented. It becomes a state. However, as a method / apparatus for applying, it is most preferable to use a coating method in which a necessary amount of the dye liquid is applied to the sheet from the beginning because it is necessary to avoid the circulation and use of the excess adhesion liquid as much as possible. An example is a method using a coating roll. In addition, a fountain coater, a bead coater, etc. can be applied. The dipping / squeezing method and the roll coating / scraping bar method are also suitable for the sheet in which the dye solution penetrates slowly.
In addition, the addition of a penetrant to the dye solution finally reduces the water resistance of coloring, and of a variety that does not adversely affect the dispersion stability of a cationic direct dye having both an anion group and a weak cation group. There are some points that are difficult to select.

The sheet to which the dye solution is attached is dried using a dryer. As the dryer, a hot air dryer, a cylinder dryer or a radiant dryer can be used, but a non-contact dryer is preferable in the initial stage.

The sheet to which the dye is attached permeates inside the sheet due to the cationic property of the dye and is fixed inside the fiber due to the direct property. Therefore, water resistance can be enhanced by blocking the cationic property with an anionic substance. . This anionic substance is preferably a substance having a plurality or a large number of anion groups and having a not so low molecular weight. For example, tannic acid and its derivatives used for the post-treatment of acid dyes have an appropriate water resistance-imparting effect and an appropriate viscosity of an aqueous dispersion. A polymer having a carboxyl group, for example, a polyacrylamide copolymer, also has a good water resistance-imparting effect, but in general, there are many high-viscosity products, and since the amount of the attached liquid is large, it is appropriate from the viewpoint of the efficiency of the drying process. It is good to select a proper variety. Further, polymer emulsions and latexes using an anionic dispersant can also be used.

The polymers are preferably water-soluble or water-dispersible, but those of the type which are insolubilized or coagulated in an acidic solution are preferable because they give excellent results in water fastness.

[0065]

With the above construction, in the invention of claim 1, when the cationic direct dye solution is impregnated or applied to the fibrous sheet material, it is fixed inside the fibers of the sheet material by ionic adsorption. Thereafter, by coating or impregnating the anionic substance dispersion liquid, the cationic property of the cationic direct dye is blocked by the anionic substance, and the water resistance is enhanced.

In the invention of claim 2, the fibrous sheet material has an affinity for the direct dye, and therefore the cationic direct dye is favorably fixed to the fibrous sheet material by the affinity.

According to the third aspect of the invention, since the anionic substance is tannic acid or its derivative, the effect of imparting water resistance and the viscosity of the dispersion can be suitably obtained. According to the invention of claim 4, since the anionic substance contains a water-repellent agent, it imparts water repellency to the sheet-like material or significantly reduces water absorption, thereby further improving the water resistance of the dye.

[0068]

According to the invention of claim 1, a long continuous colored sheet can be easily produced, various colors can be stably obtained, a colored sheet which is fast against water can be obtained, and color switching can be performed. It is easy and the generation of colored waste water can be made extremely small.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, since the fibrous sheet material has an affinity for the direct dye, the affinity directly favors the cationic direct dye. The dye can be fixed to the fibrous sheet material.

In the third aspect of the invention, since the anionic substance is tannic acid or its derivative, the effect of imparting water resistance and the viscosity of the dispersion can be suitably obtained. In the invention of claim 4, water repellency can be imparted to the sheet-like material, or water absorption can be significantly reduced, and the water resistance of the dye can be further improved.

[0071]

EXAMPLES Examples embodying the present invention will be described below. The following four types of sheets were prepared as the sheets of the examples.

(Sheet A) Wood pulp paper Bleached softwood kraft pulp A slurry having a beating degree SR25 ° of 100 parts was prepared, and 0.7 part of a polyamidoamine / epoxy wetting strength agent and a small amount of a nonionic defoaming agent were added. Then, paper having a basis weight of 55 g / m ² was produced using a cylinder paper machine.

(Sheet B) Cotton linter blending sheet Cotton linter valp Disaggregation 50 parts Bleached softwood kraft pulp Beating degree SR 35 ° 20 parts Heat-fusible polyester fiber 30 parts are mixed to prepare a slurry, and polyamide amine / epoxy wet 0.5 parts of a strong agent, water-soluble C.I. M. 0.3 for C
And a small amount of nonionic defoaming agent were added, and a basis weight of 55 g / m ² was produced using a cylinder paper machine.

(Sheet C) Polyester fiber mixed sheet Polyester fiber 1.5 d × 5 mm 50 parts Bleached softwood kraft pulp Beating degree SR 35 ° 20 parts Heat-fusible polyester fiber 30 parts are mixed to prepare a slurry, and a sheet B is prepared. Sheets were made into paper using the same additives, methods and conditions.

(Sheet D) Wood pulp sheet Mercerized softwood kraft pulp Beating degree SR8 ° 60 parts Core-sheath type heat-fusible polyester composite fiber 40 parts are mixed to prepare a slurry, and a polyamideamine / epoxy-based wet strength agent is prepared. 1 part and a small amount of a nonionic antifoaming agent were added, and paper was made in the same manner as the sheet B using a cylinder paper machine.

The test method used in each of the following examples is as follows. (Test method) ○ Water resistance fixation test A water resistance fixation test was carried out as follows as a method for judging water resistance fastness.

Only the width of the test piece differs from the JIS P8141-65 water absorption test. Width is 25 mm. Pure water is used as water. Water absorption time is 24 hours. To determine the result, the test piece is removed and dried, and then the upper end of the water absorption is determined to have a linear or spot discoloration, or the occurrence of a fading portion, and the fading of the water-immersed portion.

Dissolution test A 2 cm × 5 cm test piece was placed in a test tube, 30 c.c. of water was added, and the mixture was allowed to stand for 30 minutes and then shaken to determine the coloring of water due to the dissolution of the dye. (Example 1) Cationic direct dyes on sheets A, B and C
A 1: 1 mixed aqueous solution of Kayacel Blue CF and Kayacel Red CB (manufactured by Nippon Kayaku Co., Ltd.) was applied to the sheet so that the weight ratio of the dye was 2.0%, and the mixture was dried with a hot air dryer to 1
It was dried at 00 ° C. to obtain a lavender (light purple) colored paper. Next, aqueous solutions having different concentrations of tannic acid (concentration of 40% for dyeing aid), solid content% 0.02, 0.04,
Prepare 0.10, 0.20, 0.4, 0.8,
Each solution was applied to a colored paper in an amount of 150% and subjected to a fixing treatment of drying at 100 ° C. for 5 minutes with a hot air dryer.

The results of the dissolution test are shown in Sheets A, B, and C.
In all three types, the fixing treatment was not performed, the 0.02% solution treatment was eluted in a dark color, and the 0.8% solution treatment was eluted in a medium color. Sheet C was 0.04% neutral.

Almost no elution was due to 0.10 to 0.4% of sheet A and 0.10 to 0.20% of sheet B.
Met. In Sheet C, all other concentrations except 0.04% were found to be light-colored elution, and a slight amount of dark colored fine particles dropped off in all the concentrations.

The water-resistant fixing degree was determined for each of the sheets that had not been subjected to fixing and that had been treated with a 0.20% solution. In the case of no fixing treatment, a wide string-like stain was formed at the upper end of water absorption in all three types of sheets. At 0.20%, Sheet A was a thin and extremely light stain, Sheet B was a light stain, and Sheet C was a medium-colored stain. In each untreated sheet, discoloration of the water-immersed part was observed. (Example 2) A carboxymethyl cellulose aqueous solution (concentration: 0.5%) was applied as a fixing treatment to the colored sheet of the sheet B of Example 1 and dried by a hot air dryer. No change was observed in the hue of the colored sheet.

The result of the dissolution test was a pale color. Unfixed unprocessed turned dark. In the water resistance fixing degree test, the untreated one produced wide string-like dark stains, while the one subjected to the fixing treatment had a thin light color. (Example 3) A 20-fold product weight dilution liquid of an anionic acrylamide copolymer (Pyrex M Meisei Kagaku Co., Ltd.) was applied as a fixing treatment to the colored sheet of the sheet B of Example 1, and hot air was applied. It was dried in a dryer.

No change was observed in the hue and feel of the colored sheet. The dissolution test result was a pale color. The result of the water resistance fixing degree test was a thin linear light-colored stain. (Example 4) As a fixing treatment for the coloring sheet of the sheet B of Example 1, a 0.7% solid content aqueous solution of anionic styrene-butadiene latex (LX430 manufactured by Nippon Zeon Co., Ltd.) was applied, and hot air was applied. It was dried in a dryer. The change in hue and touch of the colored sheet was slight. No dissolution was observed in the dissolution test. The test result of the water resistance fixing degree was an extremely pale linear stain. (Example 5) Similarly, the following Kayasel dye (Nippon Kayaku Co., Ltd.)
Mixed dye solution was prepared.

Kayacel Orange CS 86 parts Kayacell Blue CF 43 parts Kayacel Black CN 21 parts That is, the above-mentioned Kayasel dye was dissolved in ion-exchanged water so that the total concentration became 1.5%. Sheets A, B, and D were impregnated with the dye aqueous solution diluted with the dye aqueous solution so that the dye / sheet weight ratio was 2.4 / 100, and dried with a hot air dryer.

The dye solution penetrated fully through the sheet. As in Example 1, an aqueous solution of tannic acid (dyeing aid) was soaked in such that the amount of tannic acid attached was 0.50% / sheet, and dried at 100 ° C. with a hot air dryer. or,
In addition to tannic acid, a fluororesin emulsion for papermaking (Asahi Guard AG550 Asahi Glass Co., Ltd.) was added as a water repellent so that the resin content was 75% of tannic acid. / Coated so as to adhere to the sheet and dried with a hot air dryer. As a result, moss green color, which was the target of color, was obtained on all the sheets.
However, the color density of the sheets was recognized, and the sheets A, D, and B became lighter in the order.

As another example, the sheet D was applied with the aqueous solution of tannic acid without being dried after the application of the dye solution and then dried with a hot air drier, and the dye solution was applied as Comparative Examples 1, 2 and 3. Dried with a hot air dryer,
And after applying the dye solution and drying with a hot air dryer,
Only the fluororesin water solution was applied and dried with a hot air dryer to prepare a product.

The test pieces of Examples 5-1 to 5-6 and the comparative example were also subjected to the elution test and the water resistance fixing degree test, respectively. Table 1 shows the results.

As shown in Table 1, in the dissolution test, all the examples showed colorless or ultra-light color, while the comparative examples showed medium color and dark color. In the water resistance fixing degree test, some of the comparative examples showed a wide dark color, while the examples obtained an extremely light color or none. In addition,
In Comparative Example 1, colored fine particles were generated.

[0089]

[Table 1]

Claims (4)

[Claims] 1. A fibrous sheet comprising a step of impregnating or coating a cationic direct dye dispersion on a fibrous sheet, and then impregnating or coating an anionic substance dispersion. How to color things. 2. The method for coloring a fibrous sheet according to claim 1, wherein the fibrous sheet contains fibers or pulped fibers having an affinity for direct dyes. 3. The fibrous sheet-like article according to claim 1, wherein the anionic substance dispersion liquid is one or more selected from anionic polymer substances, tannic acid or derivatives thereof. Coloring method. 4. The fiber according to claim 1, wherein the anionic substance dispersion liquid contains an anionic substance and a water-repellent agent which coexists with the anionic substance to form a stable dispersion liquid. For coloring a transparent sheet-like material.