JPH0598507A - Black rayon fiber - Google Patents

Abstract

PURPOSE:To obtain black rayon fiber capable of showing jet-black color properties by using cured spherical fine particles, uniformly dispersible in a spinning solution and excellent in heat and acid resistance as a pigment. CONSTITUTION:Rayon fiber is colored with amino resin cured fine spherical particles containing carbon black dispersed in a reactional product of an amino compound in which at least one guanamine selected from the group consisting of benzoguanamine, cyclohexanecarboguanamine and cyclohexenecarboguanamine accounts for 40-100wt.% with aldehydes.

Description

Detailed Description of the Invention

[0001]

This invention provides a rayon yarn excellent in gloss and jetness by using a black colorant having excellent dispersibility in a spinning dope for rayon such as viscose and spinnability. Regarding black rayon fibers.

[0002]

2. Description of the Related Art As a conventional method for producing viscose rayon, a method called undiluted dyeing, that is, a colorant such as a pigment, a sulfur dye or a vat dye is mixed and dispersed or dissolved in a spinning dope such as viscose in advance. A method for producing a colored rayon yarn for spinning is widely used. As the colorant in this case, a water-insoluble pigment is often used. Therefore, it is strongly preferred to uniformly disperse the pigment in the spinning solution in order to improve the spinnability and the gloss or color tone of the rayon yarn obtained. Required.

Generally, spinning of viscose rayon is performed by discharging a spinning dope such as viscose into a spinning bath containing a relatively high concentration of sulfuric acid and salts such as zinc sulfate and sodium sulfate. There is. When using dyes such as sulfur dyes and vat dyes as colorants, add the reducing agent in the same amount or more as the dye to solubilize the dye and then add it to viscose, but most of these dyes are dissolved. It has been pointed out that this leads to a decrease in stability. Further, when using an organic pigment or an inorganic pigment as a colorant, when the spinning solution is discharged into a spinning bath of high acid and high temperature, the pigment dispersed in viscose causes agglomeration to form coarse particles, There are drawbacks such as frequent occurrence of yarn breakage and, in some cases, clogging of discharge holes, which leads to deterioration of spinnability.

In particular, carbon black used as a coloring agent for black fibers has a very small particle size and strong surface activity, which causes aggregation and makes monodispersion very difficult, resulting in poor dispersion stability. However, there is a problem that the coloring property is severely deteriorated. As described above, when the viscose rayon fiber is processed, a coloring agent that withstands harsh conditions and has excellent dispersibility and stability is required. Therefore, it can be favorably used among commercially available pigments and dyes. The number of things is small and limited. Therefore, it is very difficult to obtain a desired color tone, and it is particularly difficult to obtain a viscose rayon yarn having excellent jet blackness.

[0005]

In the above conventional techniques, it is difficult to uniformly disperse the pigment in the spinning solution (stock solution for spinning).
Aggregation is likely to occur even when dispersed temporarily, and in the case of dyes, there are problems such as poor solubility and stability.Since the spinning bath is high acid, high salt, and high temperature, yarn breakage may occur during spinning. There is a problem with the colorability of the fibers.

The present invention solves the above-mentioned problems of the prior art, and uses black cured spherical fine particles excellent in heat resistance and acid resistance as a pigment, and the black cured spherical fine particles are uniformly dispersed in the spinning dope. An object of the present invention is to provide a black rayon fiber which is excellent in jet blackness because it is uniformly dispersed even after spinning.

[0007]

In order to solve the above problems, the present invention provides 40-100% by weight of at least one guanamine selected from the group consisting of benzoguanamine, cyclohexanecarboguanamine, and cyclohexenecarboguanamine. Carbon black (hereinafter referred to as "C
There is provided a black rayon fiber colored with spherical fine particles of a cured amino resin (hereinafter referred to as "black spherical fine particles") in which "B") is dispersed.

In the present invention, the amino resin cured product is
It is necessary that CB be dispersed therein and be colored black. For this purpose, the amount of CB is preferably in the range of 1 to 30% by weight, more preferably 5 to 20% by weight, based on the amino resin cured product. If the amount of CB is less than 1% by weight, coloring of the cured product is insufficient, and if it exceeds 30% by weight, the entire amount of CB cannot be fixed to the cured amino resin product, resulting in distorted particles. However, the particle size distribution may be broadened. Further, by using a cured amino resin as a matrix component of the black spherical fine particles, there is an advantage that a product excellent in heat resistance, solvent resistance and chemical resistance can be obtained.

In the present invention, the black spherical fine particles are, for example, those produced by polycondensing an amino resin in an emulsified state. The black spherical fine particles obtained by such a manufacturing method are integrated with CB and a cured amino resin, and are colored with CB. The black spherical fine particles obtained by such a manufacturing method have, for example, an average particle diameter in the range of 0.1 to 50 μm,
It may have an average particle diameter outside this range.

In the present invention, the black fine particles having a spherical shape means that the particle size ratio (major axis / minor axis) obtained from an electron microscopic image of 200 of the black particles is 1.
It is in the range of 0 to 1.1. The black spherical fine particles used in the present invention are spherical in shape and have no protrusions on the particle surface, and the particle diameters are substantially uniform, secondary aggregation is unlikely to occur, and the affinity with viscose is high, Excellent dispersibility in viscose. Further, since the black spherical fine particles are composed of CB having excellent light resistance and an insoluble and infusible amino resin, they are excellent in light resistance, heat resistance, solvent resistance, alkali resistance, and acid resistance. It can withstand the viscose rayon manufacturing process including high temperature operation.

The amino resin is benzoguanamine,
Cyclohexanecarboguanamine, and is a generic term for resins obtained by the reaction of an amino compound in which at least one guanamine selected from the group consisting of cyclohexenecarboguanamine accounts for 40 to 100% by weight and an aldehyde represented by formaldehyde. Any combination can be used in the present invention. Among them, benzoguanamine-formaldehyde resin and benzoguanamine / cyclohexenecarboguanamine-formaldehyde resin are preferable. The amino resin containing these guanamines as an essential component is uniformly colored by CB, and can express the jet blackness inherent to CB.

The above-mentioned three kinds of amino compounds other than guanamine are amino compounds having two or more amino groups in the molecule and are selected from the group consisting of urea, melamine, norbornanecarboguanamine, norbornenecarboguanamine and the like. One or two or more of the above. As described below, when the treated CB is used, as the amino resin, an amino compound containing 40 to 100% by weight of at least one guanamine selected from benzoguanamine, cyclohexanecarboguanamine and cyclohexenecarboguanamine, and formaldehyde are used. It is preferable to use an initial reaction product (precondensation product) obtained by polycondensation reaction, which may be etherified. When the treated CB is used, it is preferable to use such an amino resin because it has a good affinity with the treated CB and can disperse the CB uniformly.

The amino resin used in the present invention is preferably an amino resin initial reaction product having a methanol miscibility of 400% or less. The degree of methanol miscibility of the initial reaction product represents the degree of polycondensation rate of the amino resin. 2 g of the initial reaction product was dissolved in 5 g of methanol, and water was added dropwise while maintaining the temperature at 25 ° C. The value is the ratio of the weight to the weight of the initial reactant multiplied by 100.

In the present invention, a desired CB can be used from among various CBs. The shape of the CB used in the present invention is not particularly limited, but for example, in order to improve colorability (improvement in dispersibility in resin, etc.), the CB is treated with a crusher such as a ball mill to have a particle diameter. The thickness is preferably 5 μm or less, more preferably 0.1 μm or less.

In the present invention, the amount of CB used is such that CB contained in the black spherical fine particles is a cured product of amino resin and CB.
1 to 30%, preferably 5 to 20% of the total weight of
It may be set appropriately so that the ratio becomes. In order to obtain such a ratio, it is preferable to use CB in a ratio of 0.9 to 27% by weight based on the total amount of the amino resin and CB, although it depends on the kind of the amino resin and the like.

If CB is in a form treated with the compound (A) having reactivity and / or affinity with the functional group existing on the surface, CB has dispersibility in the initial reaction product of the amino compound and formaldehyde. It is possible to obtain black spherical fine particles having good color and excellent coloring. The compound (A)
Is a functional group present on the surface of CB (for example, —OH,
Compounds having a reactive group and / or affinity that can easily react with —COOH, —C═O, etc.) can be used without particular limitation. The compound (A) is, for example, a monomer or polymerizable compound having at least one aziridine group, oxazoline group, N-hydroxyalkylamide group, epoxy group, thioepoxy group, isocyanate group, hydroxyl group, amino group, imino group, or the like. The monomer may be used, or if necessary, one or two or more kinds of polymerizable monomers may be polymerized by a known procedure. Specific examples of the compound (A) include, for example, an average molecular weight of 300.
100,000 polyethyleneimine, average molecular weight 70-10
Examples are polyethylene glycol glycidyl ether, and (poly) alkylene glycol having an average molecular weight of 200 to 10,000. To treat CB with compound (A),
For example, do the following: CB and compound (A) are sufficiently kneaded by various kneaders and heated to a constant temperature to CB
The reactivity or affinity between the functional group on the surface and the functional group of the compound (A) is improved.

The emulsifier used in the production of the cured amino resin may be any emulsifier capable of forming a protective colloid, and examples thereof include polyvinyl alcohol, polyvinylpyrrolidone, carboxymethyl cellulose, alkali metal salts of polyacrylic acid, and styrene-malein. An alkali metal salt of an acid copolymer or the like is used, and among them, polyvinyl alcohol is particularly preferable. Emulsification using an emulsifier
A predetermined amount of CB is added to the amino resin and the emulsifier is directly added to the mixed system, or an aqueous solution of the emulsifier is prepared separately, and the mixture of the amino resin and CB is added to this, and the liquid is subjected to strong shearing. It can be carried out by stirring using a stirrer that gives force, for example, a colloid mill, a disper mill, a homomixer, a homogenizer and the like. The amino resin used in the above emulsification process is preferably an initial reaction product having a methanol miscibility (index of polycondensation rate) of 400% or less, more preferably 200% or less. The particle size increases with decreasing methanol miscibility, and the particle size decreases with increasing methanol miscibility. When the miscibility with methanol is more than 400%, the hydrophilicity becomes too large, and it becomes difficult to obtain monodispersed particles. The degree of condensation of the initial reaction product of the amino resin can be controlled by the degree of miscibility with methanol as described above, but can also be controlled by the degree of miscibility with GPC (gel permeation chromatography), LC (liquid chromatography), acetone or the like. Among these, operability,
It is advisable to control the acetone miscibility for reproducibility. Acetone miscibility represents the degree of polycondensation rate of amino resin. The initial reaction product (2 g) was dissolved in acetone (5 g), water was added dropwise while maintaining the temperature at 25 ° C, and the weight of water required to cause cloudiness and the initial reaction. It is a value obtained by multiplying the weight ratio of the product by 100. The degree of miscibility with acetone of the initial reaction product is preferably 50 to 500%, more preferably 100 to 300%. If the acetone miscibility exceeds 500%, it becomes difficult to obtain particles, and if it is less than 50%, it becomes difficult to form spherical fine particles.

The amount of the emulsifier added is 1 to the amino resin.
The range is preferably 30%, more preferably 2 to 10%. The particle size can be reduced by increasing the amount of the emulsifier used, and the particle size can be increased by decreasing the amount of the emulsifier used. If the amount of emulsifier added is less than 1%, emulsification may not be possible.
If it exceeds, it may be difficult to separate fine particles obtained by curing as single particles. Further, increasing the stirring efficiency decreases the particle size, and decreasing the stirring efficiency increases the particle size. This is because raising and lowering the stirring efficiency for making the emulsion state is related to the magnitude of the force for shearing the initial reaction product. As described above, by appropriately selecting the polycondensation rate of the amino resin, the amount of emulsifier, the stirring efficiency, etc., it is possible to synthesize black spherical fine particles having a true spherical shape, a narrow particle size distribution, and a target particle diameter.

The curing catalyst is a polycondensation catalyst of amino resin, for example, mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid; carboxylic acids such as benzoic acid, phthalic acid, acetic acid, propionic acid and salicylic acid; ammonium chloride, ammonium phosphate and the like. Ammonium salts of benzene sulfonic acid such as benzene sulfonic acid, paratoluene sulfonic acid, and dodecylbenzene sulfonic acid can be used alone or in combination. The curing catalyst is a solid content of uncured amino resin emulsion colored with CB (excluding pigment)
, Preferably 0.01 to 10% (treated C
When B is used, it is 0.01-5%), more preferably 0.2-5% (when treated CB is 0. 5%).
2 to 2%). If the addition amount of the curing catalyst is too large, the emulsified state may be destroyed and aggregates may be generated.If the addition amount is too small, the curing may be insufficient or the curing may take a long time. Not preferable. Curing is carried out, for example, by holding at a temperature in the range of 10 to 200 ° C. for at least 1 hour, and then at room temperature or under pressure.
Curing is performed at a temperature in the range of 0 to 200 ° C., and when the cured product becomes insoluble in acetone, methanol, methyl ethyl ketone, dioxane, dimethylformamide, etc., the curing is terminated.

After the completion of the curing reaction, the black spherical fine particles can be separated by a known method, for example, various separation methods such as a natural sedimentation method, a centrifugal sedimentation method and a decantation, and a separation by filtration can be freely used. Can be used for. Further, black spherical fine particles obtained by separation are water and various organic solvents, for example, nonpolar solvents such as toluene and xylene, methyl ethyl ketone, methanol, ethanol, isopropyl alcohol, dimethylformamide,
It can be obtained as a paste or a dispersion by dispersing in a polar solvent such as tetrahydrofuran or a mixed solvent composed of these. After the separating operation, the black spherical fine particles can be dried by a conventionally known method such as natural drying, reduced pressure drying, and hot air drying. After the drying operation, heat treatment at a temperature of 100 to 200 ° C. further improves the heat resistance, water resistance, solvent resistance, etc. of the target black spherical fine particles. Is preferably applied. However, if the drying process is performed at a relatively high temperature, the heat treatment is simultaneously performed, and thus, in such a case, the heat treatment may not be performed. The dried black spherical fine particles can be crushed by a force such as a ball mill, hammer mill, jet mill or the like to release the agglomerated state, to obtain black spherical fine particles. Further, it is of course possible to disperse the black spherical fine particles after the drying operation in a solvent to form a paste or a dispersion.

The average particle diameter of the black spherical fine particles used in the present invention is, for example, in the case of spinning a rayon yarn of 5 denier single yarn, the viscose discharge hole is about 80 μm, and the dispersibility in viscose is If you consider, 0.1
The range is preferably 10 μm, and more preferably 0.1
It is in the range of 2 μm. In the present invention, the black spherical fine particles are used by adding and mixing them to a spinning dope for rayon (for example, viscose or alkali cellulose). When mixing, no special mixing / kneading device is required, and an extremely simple mixing device is sufficient. The composition of the spinning bath for spinning viscose or viscose to which the colorant of the present invention is applied is not particularly limited.

In the present invention, the amount of black spherical fine particles added is preferably in the range of 0.1 to 20 parts by weight, more preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the spinning dope for rayon before addition. , And more preferably 0.3 to 3 parts by weight. If the amount of black spherical particles added is less than 0.1 part by weight, the blackness of rayon may be insufficient.
If the amount exceeds 0 parts by weight, yarn breakage or the spinneret may be blocked during spinning. Further, in the present invention, when the black spherical fine particles are added, a coloring agent such as another pigment or dye, or a surfactant for assisting the dispersion of the coloring agent can be used together.

[0023]

By using black spherical fine particles that are colored with CB, have a substantially uniform particle size, and have a high affinity with the spinning dope for rayon such as viscose and are insoluble and infusible, rayon fibers having excellent jetness can be obtained. The black spherical fine particles used in the present invention have excellent stability in a dispersed state and excellent jet blackness as compared with CB particles which have been conventionally used as a coloring agent. Furthermore, due to the light scattering of black spherical particles in rayon, it shows the unique luster of viscose rayon,
It is possible to obtain rayon yarns which exhibit a very favorable soft gloss and jet blackness.

[0024]

EXAMPLES Specific examples and comparative examples of the present invention will be shown below, but the present invention is not limited to the following examples.
First, an example of producing black spherical fine particles will be described. -Production Example 1-A flask equipped with a stirrer, a reflux condenser, and a thermometer has 100 g (0.53 mol) of benzoguanamine, 50 g (0.26 mol) of cyclohexanecarboguanamine, and a concentration of 37%.
Formalin (37% aqueous formaldehyde solution) 15
0 g (formaldehyde 1.85 mol), and 10
% Aqueous sodium carbonate solution (0.65 g) was added, and the mixture was stirred and reacted at a temperature of 94 to 95 ° C. for 6 hours to obtain an initial condensate having a methanol miscibility of 35% and an acetone miscibility of 150%. CB (M manufactured by Mitsubishi Kasei Co., Ltd.
15g of A600) is added, stirred for 30 minutes, and CB
A black colored initial reaction product was obtained.

Separately, Kuraray Poval 205 (polyvinyl alcohol partial hydrolyzate manufactured by Kuraray Co., Ltd.) 8.0
g was dissolved in 140 g of water and the temperature was raised to 90 ° C., and the mixture was stirred at 7,000 rpm using a homomixer (M type, manufactured by Tokushu Kika Co., Ltd.). The black-colored initial reaction product was added to the Kuraray Poval aqueous solution under stirring to obtain a black emulsion. This emulsion was cooled to 40 ° C., then 4.1 g of dodecylbenzenesulfonic acid was added, the temperature was gradually raised, and the mixture was heated and stirred at 50 ° C., 70 ° C., and 90 ° C. for 2 hours each in order to obtain an emulsified state. Polycondensation curing was carried out to obtain a suspension of spherical fine particles of amino resin cured product colored in black.

Next, the resin spherical fine particles were separated from the emulsion by filtration, washed with water, heat-treated at 150 ° C. for 5 hours, and then lightly crushed in a mortar to obtain black spherical fine particle powder.
The particle size of the black spherical fine particles thus obtained was measured with a Coulter counter TA2 type (manufactured by Coulter Co.), and the average particle size was 2.2 μm, and the particle size ratio measured from an electron microscopic image was 1.05. Yes, the CB content is
It was 8.3% by weight.

-Manufacturing Example 2-First, an example of processing CB will be described. Laboplast mill (manufactured by Toyo Seiki Co., Ltd.), 100 parts by weight of CB (MA600 manufactured by Mitsubishi Kasei Co., Ltd.), and Denacol EX-171 (manufactured by Nagase Kasei Kogyo Co., Ltd.), which is lauryl alcohol polyethylene glycol glycidyl ether having a molecular weight of 902. Charge 100 parts by weight and stir 1
After kneading at a temperature of 00 to 200 ° C. for 20 minutes, then cooling,
A treated CB was obtained.

In a flask equipped with a stirrer, a reflux condenser and a thermometer, 150 g (0.80 mol) of benzoguanamine and 150 g of formalin having a concentration of 37% (formaldehyde 1.
85 mol) and 0.6 g of a 10% aqueous sodium carbonate solution were charged, and the mixture was reacted with stirring at a temperature of 94 to 95 ° C. for 6 hours to obtain an initial condensate having a methanol miscibility of 35% and an acetone miscibility of 150%. It was To this initial condensate, 30 g of CB treated as described above was added and stirred for 30 minutes to obtain a reaction product colored black with CB.

Separately, Kuraray Poval 205 (polyvinyl alcohol partial hydrolyzate manufactured by Kuraray Co., Ltd.) 10.0
The aqueous solution obtained by dissolving 140 g of water in 140 g was heated to 90 ° C. and stirred at 8000 rpm using a homomixer (M type manufactured by Tokushu Kika Kogyo Co., Ltd.). The black-colored initial reaction product was added to the Kuraray Poval aqueous solution under stirring to obtain a black emulsion. This emulsion was cooled to 40 ° C., then 4.1 g of dodecylbenzenesulfonic acid was added, the temperature was gradually raised, and the mixture was heated and stirred at 50 ° C., 70 ° C., and 90 ° C. for 2 hours each in order to obtain an emulsified state. Polycondensation curing was carried out to obtain a suspension of spherical fine particles of amino resin cured product colored in black.

Next, spherical fine particles were separated from the suspension by filtration, washed with water, heat-treated at 150 ° C. for 5 hours, and then lightly crushed in a mortar to obtain black spherical fine particle powder. The particle size of the black spherical fine particles thus obtained was measured with a Coulter Counter TA2 type (manufactured by Coulter Co.), and the average particle size was 0.5 μm, and the particle size ratio measured from an electron microscopic image was 1.07. Yes, CB content is 8.1
% By weight.

-Production Example 3- In the same manner as in Production Example 2 except that 75 g of benzoguanamine and 75 g of melamine were used in place of 150 g of benzoguanamine and that the amount of formalin was changed from 150 g to 165 g. Black spherical particles were obtained. The particle size of the black spherical fine particles obtained in this manner is the Coulter Counter TA2 type (manufactured by Coulter)
The average particle diameter was 0.6 μm, the particle diameter ratio was 1.08 measured from an electron microscopic image, and the CB content was 7.8% by weight.

-Production Example 4- Black spherical fine particles were obtained in the same manner as in Production Example 2 except that 150 g of cyclohexanecarboguanamine was used instead of 150 g of benzoguanamine.
The particle size of the black spherical particles thus obtained was measured with a Coulter counter TA2 type (manufactured by Coulter Co.), and the average particle size was 0.7 μm, and the particle size ratio measured from an electron microscopic image was 1.08. Yes, the CB content is
It was 8.2% by weight.

-Production Example 5- In Production Example 2, the treated CB was added in an amount of 114 g.
Black spherical fine particles were obtained in the same manner as in Production Example 2 except that The particle size of the black spherical fine particles thus obtained was measured with a Coulter counter TA2 type (manufactured by Coulter Co.), and the average particle size was 1.2 μm, and the particle size ratio measured from an electron microscope image was 1.08. Yes, CB
The content was 25.1% by weight.

Next, the colorants used in the comparative examples will be described. -Production Example 6-In a 500 ml glass bottle, 150 g of 3 mm glass beads was placed, 60 g of CB (MA600 manufactured by Mitsubishi Kasei Co., Ltd.) and 0.6 g of Emulgen A90 (a nonionic surfactant manufactured by Kao Corporation) as a surfactant, 180 g of water was added and dispersed for 1 hour with a paint shaker (manufactured by Toyo Seiki Co., Ltd.) to obtain a 25% CB aqueous dispersion.

The particle size distribution of the obtained CB aqueous dispersion was measured with a Coulter counter TA2 type (manufactured by Coulter Co.), and it was found that the particles were uniformly dispersed with an average particle diameter of 0.45 μm, but they were aggregates of primary particles. .. -Example 1-The black spherical fine particles (average particles) obtained in Production Example 1 were added to 100 parts by weight of viscose having a viscose composition of 8.5% by weight of cellulose, 6.0% by weight of total alkali, and 11.8 of Hotten-Rot number. 1 part by weight (diameter: 2.2 μm) was added and mixed well to prepare a colored viscose composition. Using this composition, the composition is sulfuric acid 150 g / l, sodium sulfate 345 g / l,
Spinning speed of 15g / l zinc sulfate into a spinning bath at a temperature of 60 ° C 9
Spinning at 0m / min, immersion length 60cm, 50 denier / 20
A filament rayon yarn was obtained. The rayon yarn obtained was a yarn exhibiting soft luster and jet blackness.

Example 2 100 parts by weight of the same viscose as used in Example 1,
Black spherical fine particles obtained in Production Example 2 (average particle size 0.5
μm) 1 part by weight was added and mixed well to prepare a colored viscose composition. Using this composition, the composition is sulfuric acid 1
Spinning was carried out with 00 g / l, sodium sulfate 350 g / l and zinc sulfate 20 g / l into the first coagulation bath at a temperature of 40 ° C. Then, sulfuric acid 1
The drawing was completed by introducing into a second coagulation bath at a temperature of 90 ° C. consisting of 0 g / l. The rayon yarn obtained was cut into 50 mm and dried to obtain rayon staple.

The rayon staple obtained was a thread of 5 denier, which was very excellent in jet blackness. Also, during spinning,
There were no troubles such as yarn breakage and blockage of the viscose discharge port. -Example 3-A rayon yarn was obtained in the same manner as in Example 1 except that the black spherical fine particles in Example 1 were changed to those obtained in Production Example 3.

The rayon yarn thus obtained was a yarn exhibiting soft luster and jet blackness. -Example 4-A rayon yarn was obtained in the same manner as in Example 1 except that the black spherical particles in Example 1 were changed to those obtained in Production Example 4.

The rayon yarn thus obtained was a yarn exhibiting soft luster and jet blackness. -Example 5-A rayon yarn was obtained in the same manner as in Example 1 except that the black spherical fine particles in Example 1 were changed to those obtained in Production Example 5.

The rayon yarn thus obtained was a yarn exhibiting soft luster and jet blackness. -Comparative Example 1-In the same 100 parts by weight of viscose as used in Example 1,
CB with particle size of 15 nm (MA600 manufactured by Mitsubishi Kasei Co., Ltd.)
1 part by weight was added and mixed well to prepare a colored viscose composition. With this composition, the composition is sulfuric acid 150 g /
l, sodium sulfate 345 g / l, zinc sulfate 15 g / l, temperature 6
A rayon yarn of 50 denier / 20 filaments was obtained by spinning in a spinning bath at 0 ° C. at a spinning speed of 90 m / min and an immersion length of 60 cm. The rayon yarn thus obtained was a black matte yarn.

Comparative Example 2 100 parts by weight of the same viscose as used in Example 1,
4 parts by weight of the CB aqueous dispersion obtained in Production Example 6 was added and mixed well to prepare a colored viscose composition. Using this composition, the composition is sulfuric acid 150 g / l, sodium sulfate 345
Spinning was performed at a spinning speed of 90 m / min and a dipping length of 60 cm into a spinning bath at a temperature of 60 ° C. with g / l and zinc sulfate of 15 g / l to obtain 50 denier / 20 filament rayon yarn. The rayon yarn thus obtained was a black matte yarn. Also, during spinning,
Problems such as yarn breakage and blockage of the viscose discharge port occurred.

Comparative Example 3 Under the same conditions as in Comparative Example 1, except that 25 parts by weight of the black spherical fine particles obtained in Production Example 1 were used in place of 1 part by weight of CB having a particle diameter of 15 nm in Comparative Example 1. When spinning, problems such as yarn breakage and blockage of the viscose discharge port occurred during spinning.

[0043]

The black rayon fiber of the present invention exhibits a unique luster and jet blackness. Therefore, by using the black rayon fiber of the present invention, it is possible to obtain a rayon yarn having extremely preferable soft gloss and jet blackness.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masao Baba 1 992 Nishikioki, Kamahama, Aboshi-ku, Himeji-shi, Hyogo Inside Nippon Shokubai Himeji Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. Carbon black is dispersed in a reaction product of an amino compound and an aldehyde in which at least one guanamine selected from the group consisting of benzoguanamine, cyclohexanecarboguanamine, and cyclohexenecarboguanamine accounts for 40 to 100% by weight. Black rayon fibers colored with spherical fine particles of cured amino resin. 2. Amino resin cured product spherical fine particles of 0.1 to
The black rayon fiber according to claim 1, which is contained in a proportion of 20% by weight.