JPH0135108B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a recycled cellulose fiber structure having excellent washing resistance, and more particularly, to a method for producing a recycled cellulose fiber structure having excellent shape stability against washing, color fastness, and resilience. Conventionally, knitted fabrics made of recycled cellulose fiber structures, such as rayon, polynosic, etc., have practical deficiencies as clothing, such as poor shape stability upon washing and insufficient color fastness. The purpose of improving morphological stability is (1) improving the quality of yarn (cotton) by improving crystallinity during the spinning process, (2)
Improvement methods such as resin processing have been proposed and implemented. However, method (1) has problems in versatility, manufacturing cost, etc., and furthermore, it cannot be expected to improve color fastness. Method (2) has been practiced in the past, but it has the disadvantage that the shrinkage rate increases with repeated washing, probably due to the durability of the resin finishing agent. Also, the purpose of mercerization performed on cotton, which is also a cellulose fiber, is to (1) improve luster;
(2) Improved dyeability, (3) Improved area stability, etc. When this process is applied to recycled cellulose fiber structures, the morphological stability improves due to the strong alkaline treatment of caustic soda solution. However, due to the dissolution and solidification phenomenon of the fibers, the strength is greatly reduced, and the softness and drapability of the rayon material are lost, making it unsuitable for practical use. Many studies have been conducted to prevent the dissolution and solidification of fibers caused by alkali treatment. For example, there is a method in which the fiber surface is previously treated with a protective agent such as polyvinyl alcohol, starch, etc., and then treated with alkali. However, with this method, slight variations in alkali concentration, alkali removal conditions, etc. can cause variations in strength, variation in dyeability, and dissolution of fibers.
It is difficult to apply it industrially. On the other hand, with regard to color fastness, the selection of dyes used, soaping after dyeing, post-treatment with fixing agents, etc. have been carried out, but the dyeability cannot be said to be sufficient, especially in dark colors, where the surface dyeing of the dye is large. However, it has the disadvantage that color fastness is not sufficient. An object of the present invention is to provide a novel recycled cellulose fiber structure that has excellent washing resistance, that is, excellent morphological stability and color fastness when washed, and is rich in resilience. To provide a recycled cellulose fiber structure with excellent dye fixation rate and no variation in strength or dyeability among products. That is, in the present invention, after applying a hydrophilic film-forming substance to a fiber structure mainly composed of recycled cellulose fibers, an aqueous alkali metal hydroxide solution is applied in the presence of an inorganic electrolyte and a swelling control agent, and then , a method for producing a recycled cellulose fiber structure with excellent washing resistance, characterized by removing the hydrophilic film-forming substance. The fiber structures mainly made of recycled cellulose fibers as used in the present invention include yarns, knitted fabrics, woven fabrics, and nonwoven fabrics mainly made of rayon. It can include natural fibers such as silk, synthetic fibers such as nylon, polyester, and acrylic. In the present invention, the hydrophilic film-forming substances include starch-based, cellulose-based, polyvinyl alcohol-based,
Examples include sodium alginate compounds, which can be used alone or in combination. The amount of the film-forming substance applied to the fiber structure is:
0.3% owf or more is good, and 0.5 to 20% owf is preferable.
As for the application method, the film-forming substance solution is applied to the fiber structure by a padding method, a dip coating method, etc., and then dried to form a film.
In this case, from the viewpoint of stability of the film-forming substance solution and improvement of the texture of the fibrous structure, an anionic or nonionic surfactant may be used in combination. It is also possible to make an inorganic electrolyte and a swelling control agent coexist in the film-forming substance solution so that the three can be applied at the same time. (Of course, the inorganic electrolyte and swelling control agent may be applied by an appropriate method after applying the above-mentioned film-forming substance to the fibrous structure.) Examples of the inorganic electrolyte include common salt, mirabilite, etc. The amount applied to the product is preferably 3.0% owf or more, preferably 4 to 7% owf. Swelling control agents include ester compounds, amines, amides, polyoxyethylene glycol derivatives, carboxylic acid salts, quaternary ammonium salts, naphthlates, phenolates,
There are mixtures of these, among which urea and polyethylene glycol are preferred. The amount of the swelling control agent applied to the fiber structure is 3.0% owf.
The above is preferable, and 5 to 7% owf is preferable. Subsequently, it is treated with an aqueous alkali metal hydroxide solution. However, during such treatment, it is important that the inorganic electrolyte and the swelling control agent are present, and either both have been applied to the fiber structure to be treated in advance, or if they are not applied, alkali metal hydroxide Both must be contained in the aqueous solution. Examples of the alkali metal hydroxide include cesium hydroxide, rubidium hydroxide, potassium hydroxide, sodium hydroxide, lithium hydroxide, etc. Among them, it is preferable to use sodium hydroxide. The concentration of alkali metal hydroxide aqueous solution varies depending on the type of hydroxide used, but in the case of sodium hydroxide
30g/or more, preferably 40-200g/. Such aqueous alkali metal hydroxide solution treatment is carried out by applying the solution to the fibrous structure by spraying, padding, or the like. After the treatment, the fibrous structure is optionally subjected to a tension treatment, followed by removal of the alkali metal hydroxide.
The hydroxide can be removed using water at 40 to 100° C. using a shower, an open soaper, a winch, etc., but hydrochloric acid, sulfuric acid, acetic acid, etc. at an appropriate concentration may also be used. Next, the previously applied hydrophilic film-forming substance is removed from the fibrous structure, but this can usually be done using a combination of enzyme-based desizing agents, peroxide-based desizing agents, weakly alkaline soaping agents, etc. . Although it is possible to obtain a regenerated cellulose fiber structure according to the present invention in the manner described above, it is preferable to subject it to subsequent normal processing steps, paying the following precautions as necessary. For example, in the scouring and bleaching process, it is undesirable to apply strong treatment under strong alkalinity, as is usually done with cotton.It is preferable to scouring with an alkaline agent such as soda ash, and the bleaching process requires the same care as the scouring process. Generally, it is preferable to carry out the process using hydrogen peroxide, sodium chlorite, etc. by the immersion method, pad roll method, pad steam method, or the like. In the dyeing process, direct dyes, reactive dyes, vat dyes, sulfur dyes, naphthol dyes, etc., which are commonly used for dyeing cellulose fibers, are used. The method is not particularly limited, and commonly used continuous methods, exhaustion methods, pad batch methods, etc. can be applied. In particular, conventional pad dry dyeing methods for rayon materials have been considered difficult, as the surface fuzz is insufficiently dyed, resulting in poor appearance, perhaps because the dye diffusion is slower than that of cotton.
The modified fiber structures according to the invention can be dyed without difficulty. Moreover, its dye density, sharpness, color fastness, etc. are very excellent. Furthermore, it is also preferable to subject the fiber structure of the present invention to resin processing. Resin processing uses glyoxal resin, urea-formalin resin, uron resin, propylene urea resin, melamine resin, epoxy resin, polyamide resin, urethane resin, and polyacrylic resin, which are generally used for cellulose fibers. type resin, polyvinyl acetate type resin, etc. may be used alone or in combination, and various softeners may be used in combination as necessary. The resin processing method is not particularly limited, and may be carried out by conventional methods such as padding, coating, and spraying. The fiber structure obtained as above is made of modified regenerated cellulose fibers, and when the regenerated cellulose fibers are measured by X-ray diffraction method,
The intensity ratio of the peak intensity at a diffraction angle of 15.5 degrees, which is typical of cellulose, and the peak intensity at a diffraction angle of 20.2 degrees, which is typical of cellulose, is ₁ (2θ = 15.5°) / ₂ (2θ =
20.2°) is 8 or more. That is, in terms of the ratio of cellulose to cellulose contained in the fibers, the regenerated cellulose fibers according to the present invention have a higher ratio of cellulose than ordinary fibers.
However, if this ratio becomes too high, the fiber structure tends to become hard, so it is preferable to keep the value of _1/2 at 18 _or less. In addition, the regenerated cellulose fibers according to the present invention have a larger fiber diameter than normal ones (that is, the fiber diameter is larger than that before processing due to the processing described below), and a fiber cross-sectional area A (μ ² ) and fineness D (denier)
The ratio A/D is 145 or more. Furthermore, the regenerated cellulose fiber according to the present invention has a swelling degree of 50% or less after 5 minutes of immersion in water, but if the swelling degree is too small, when the fiber structure is later subjected to resin processing, the processing It is preferable that the degree of swelling is at least about 30, as this may reduce the durability of the material. Such a fiber structure of the present invention is subjected to dyeing processing or resin processing as necessary. Thus, the fiber structure of the present invention has excellent morphological stability when washed, excellent color fastness, and is highly resilient, and also has no variation in strength or dyeability among products, making it an extremely advantageous product industrially. It is. The present invention will be specifically explained below using Examples. In addition, the peak intensity ratio measured by the X-ray diffraction method referred to in this specification _{is 1/2} , and the ratio of fiber cross-sectional area and fineness is A/ ₂ .
D, water swelling degree, washing fastness, dyeing density ratio, strength,
The washing shrinkage rate and wrinkle resistance were measured according to the following method. (1) Peak intensity ratio ₁ / measured by X-ray diffraction method
₂ Using an X-ray analyzer, analyze the incident X-rays on the sample (thread)
The diffraction angle (2θ) from the baseline connecting 8 degrees and 30 degrees with a straight line is 15.5. Find the peak intensities at 20.2° and 20.2°, and calculate the intensity ratio ₁ (2θ=15.5°)/ ₂ (2θ=
20.2°) was determined. (2) Ratio A/D of fiber cross-sectional area and fineness The ratio of the cross-sectional area A and fineness D of the regenerated cellulose fibers constituting the fiber structure was determined as A (μ ² )/D (denier). (3) Water swelling degree It was determined from the fiber cross-sectional area (A) under the official moisture content and the fiber cross-sectional area (B) after 5 minutes of immersion in water, as B-A/A x 100 (%). (4) Washing fastness Determined using JIS L-0844 A2 method. (5) Staining density ratio The optical density K/S at the maximum absorption wavelength was determined using a spectrophotometer, and the relative comparative density was shown. (6) Strong fabric: Determined by JIS L-1079 Elmendorf method. Knitted fabric: Obtained using JIS L-1018 B method. (7) Washing shrinkage rate Fabric: Determined according to JIS L-1042 F-2 method. Fabric: Obtained using JIS L-1042 F-1 method. (8) Wrinkle resistance determined by JIS L-1096 Monsanto method. Example 1 A plain woven fabric with a density of 90 warps and 60 threads/inch of weft was woven using 30 count yarn made of rayon cotton (1.5 denier, cut length 50 mm). Next, an aqueous solution of the film-forming substance shown in Table 1 was applied using a mangle with a squeezing rate of 80%, and then dried at 120°C. Using this fabric, the fabric was immersed in an aqueous solution with various caustic soda concentrations shown in Table 1 (liquid temperature 25°C) for 20 seconds, and then squeezed with a mangle with a squeezing rate of 80%.
The alkaline agent was completely removed from the fabric by washing with hot water at ℃. Then, the size agent was completely removed using an enzyme desizing agent. Next, Remazol Black
B Hoechst (reactive dye) 30g/, water glass
A dye solution of 100 g/ml was applied using a mangle with a squeezing rate of 80%, sealed with a vinyl film, and left for 20 hours, followed by soaping and drying. Next, Sumitex Resin ULW (Sumitex
Resin ULW urea-formalin resin manufactured by Sumitomo Chemical Co., Ltd.) 350g/, Sumitex Accelerator
A resin liquid consisting of 20g/ACX (catalyst made by Sumitomo Chemical Co., Ltd.) and 30g/Silicolane 810 (silicon softener made by Ippo Chemical Co., Ltd.) was applied using a mangle with a squeezing rate of 80%, dried at 120℃, and then dried at 150℃. The sample was heat-treated for 4 minutes. The results obtained are shown in Table 1.

[Table] Example 2 Feingum SH-20 was added to the fabric used in Example 1.
(Daiichi Kogyo Co., Ltd., cellulose derivative) 10g/80
% squeezing rate mangle, and then dried at 120°C. An aqueous solution (liquid temperature: 25° C.) having the composition shown in Table 2 was applied to this fabric and washed in the same manner as in Example 1, and then the size agent was removed. Next, Procion Brilliant Blue
H3R (Procion Brilliant Blue H3R I, C, I
A dyeing solution consisting of 30 g/reactive dye (manufactured by the company), 100 g/urea, and 20 g/soda ash was applied using a mangle with a squeezing rate of 80%, then dried at 120°C, and then
After heat treatment at 150°C for 3 minutes, uninherent dyes were removed with hot water at 80°C and dried. Subsequently, the same resin processing as in Example 1 was performed. The results obtained are shown in Table 2.

[Table] Example 3 Cornstarch was added to the same rayon yarn as in Example 1.
An aqueous solution consisting of 10g/, polyvinyl alcohol 2g/, Sofnal 950 (anionic activator made by Ippo Co., Ltd.) 5g/, mirabilite 50g/, and polyethylene glycol 40g/ was applied using a mangle with a squeezing ratio of 80%, and then dried at 120°C. did. A twill fabric with a density of 80 warps and a weft of 78 threads/inch was woven using this yarn for the warp and 30 count polyester spun yarn for the weft. This fabric was treated in the same manner as in Example 1 with 100 g of caustic soda/aqueous solution (liquid temperature 25°C), and then the size agent was completely removed. The warp rayon of the obtained fabric has an X-ray intensity ratio of
₁ = ₂ = 15.5, fiber cross-sectional area A/fineness D = 168μ ² /denier, water swelling degree of 37%, no loss of strength, soft texture, both longitudinal and latitudinal directions,
The washing shrinkage rate was 1.0% or less. Example 4 A milled knitted fabric was knitted using Polynosik No. 30 yarn (1.5 denier, 51 mm cut cotton). Cornstarch 15g/, salt 30g/ for this knitted fabric
, an aqueous solution containing 50 g of urea was applied using a mangle with a squeezing rate of 100%, and dried at 100°C. Next, it was treated with 200 g of caustic potassium/aqueous solution in the same manner as in Example 1, and then cornstarch, salt, and urea were completely removed. This sample is called (a). In addition, a sample (b) is obtained by removing cornstarch, salt, and urea in the same manner as in Example 1 without performing caustic potash treatment. Next, (a) and (b) at the same time, an aqueous solution of 30 g/g of Ginsoft 66 (anionic softener manufactured by Daiichi Kogyo Co., Ltd.) was applied at a squeezing rate of 100.
%, dried at 120°C, and finished with a density of 31 wales and 39 courses. The results obtained in the third
Shown in the table.

【table】

Claims (1)

[Claims] 1 After applying a hydrophilic film-forming substance to a fiber structure mainly composed of recycled cellulose fibers, an aqueous alkali metal hydroxide solution is applied in the presence of an inorganic electrolyte and a swelling control agent, and then the hydrophilic film-forming substance A method for producing a recycled cellulose fiber structure with excellent washing resistance, which comprises removing film-forming substances.