JPS628558B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for improving the dyeability of cellulosic textile products and performing sublimation transfer printing using a sublimable dye.

The sublimation transfer printing method has begun to be widely used in recent years because of its simple dyeing process and the fact that it does not cause pollution such as pollution of waste water caused by dyes, pastes, and other chemicals. However, this sublimation transfer printing method is hardly used for natural cellulose fibers such as cotton and hemp, or cellulose fibers including regenerated cellulose fibers such as rayon. This is because there are no suitable sublimable dyes that can dye these cellulose fibers. On the other hand, among the disperse dyes that have the ability to dye synthetic fibers, there are many that do not have the ability to directly dye cellulose fibers, but have appropriate sublimability. Therefore, if cellulose fibers are modified to have dyeability with disperse dyes, it is expected that the sublimation transfer printing method using disperse dyes will be applied. The following methods have been proposed as methods for modifying cellulose fibers in order to improve their dyeability with disperse dyes.

(b) Chemical treatment methods such as aromatic acylation of -OH groups in cellulose molecules (for example, JP-A-51
-99185).

(b) A method of treatment with a resin or a crosslinking agent (for example, JP-A-50-38213).

(c) A method of swelling cellulose fibers with polyhydric alcohol or derivatives, etc.
Publication No. 30686).

(d) Regarding silk fiber products, a method of graft polymerizing vinyl monomers (Japanese Unexamined Patent Publication No. 1973
101677).

However, the above-mentioned processing methods also have advantages and disadvantages in terms of practicality, and are not necessarily satisfactory. For example, the chemical improvement method (a) is complicated and requires a huge amount of equipment, making it impractical in terms of cost. Furthermore, the product obtained by sublimation transfer printing has the disadvantage that the texture is hardened and physical properties such as poor hygroscopicity are deteriorated. The treatment method (b) is advantageous in terms of cost, but because it uses a chemically active reactive resin, the physical properties are unstable, such as color development changing over time after treatment. Furthermore, since melamine resin or its analogues are used, there are problems such as generation of formalin odor. The method (c) provides a bright hue and has no problem in terms of color development, but it is not perfect in terms of staining intensity and requires combination with the process (b).

On the other hand, method (d) gives a product with good color development and dyeability, but since oxygen in the air is thought to act as a polymerization inhibitor, the grafting reaction is generally carried out in a nitrogen gas atmosphere. . That is, a method has been adopted in which polymerization proceeds while cellulosic fiber products are immersed in a vinyl monomer emulsion in a closed batch process. However, since the polymerization is carried out in the bath in which the cellulosic fiber product is immersed in this manner, there is a drawback that the post-treatment of the fiber product and the bath becomes complicated due to the production of homopolymer in the bath. In particular, the loss of the vinyl monomer polymerized in the bath water phase is unavoidable, and the polymer attached to the textile product is merely attached, resulting in a disadvantage that the grafting efficiency is low. Furthermore, since this method necessarily requires batch processing, it is also disadvantageous in terms of processing cost.

On the other hand, research has also been conducted on methods of irradiating ionizing radiation when graft polymerizing vinyl monomers to cellulose fiber products to improve dyeability; Regardless of whether irradiation is used as a pretreatment, continuous irradiation is not possible due to reasons such as the long reaction time when graft polymerizing vinyl monomers, and the fact that the polymerization system must be carried out in a nitrogen atmosphere because oxygen acts as a polymerization inhibitor. Processing is difficult and only batch processing can be applied. For this reason, the processing cost becomes high, and it is difficult to improve uniform dyeing properties.

In view of the above-mentioned drawbacks of the prior art, the present invention improves the disperse dye dyeing properties of cellulose-based textile products and performs sublimation transfer printing. The main purpose of this invention is to provide a consistent method for dyeing cellulose-based fiber products that can be supplied at a relatively low cost.

According to the research of the present inventors, in order to achieve this purpose, cellulose fiber products that have been pre-irradiated with ionizing radiation are impregnated with a vinyl monomer, and after being removed from the impregnation bath, they are placed in a heated steam atmosphere. It has been found that it is extremely effective to carry out a dyeability improvement treatment by graft polymerization. The method for dyeing cellulose fiber products of the present invention includes:
This is based on this knowledge, and more specifically, cellulose-based textile products are activated by irradiation with ionizing radiation, impregnated with a vinyl monomer solution, and then the textile products taken out from the impregnation solution are heated with steam. The method is characterized in that the impregnating monomer is graft-polymerized onto the textile product by contact with the textile product, and the textile product subjected to the graft polymerization treatment is then subjected to pressure and heat treatment while in contact with a transfer paper having a sublimable dye layer. .

The present invention will be explained in more detail below. In the following description, percentages and parts are based on weight unless otherwise specified.

Cellulosic fiber products to be treated by the method of the present invention include natural cellulose fibers such as silk, hemp, and wood fibers, yarns, woven fabrics, and knitted fabrics made of cellulose fibers alone, such as natural cellulose fibers such as silk, hemp, and wood fibers; regenerated cellulose fibers such as rayon;
paper, non-woven fabrics, or these cellulosic fibers and synthetic fibers such as polyester, polyamide,
Examples include blended, interwoven, and interwoven products with acrylic fibers, etc., as well as mixed papers, mixed nonwoven fabrics, and the like. Of course, in order to apply sublimation transfer printing, it is preferable to use a sheet-like object such as cloth, but it is also possible to apply dyeability improvement treatment to the yarn, then knit and weave it into cloth, and then perform sublimation transfer printing. It is.

According to the present invention, such a cellulose fiber product (hereinafter, the explanation will be continued as a representative example of cloth) is first subjected to pretreatment such as desizing and scouring, and then irradiated with ionizing radiation to form a cloth. forming radical species on top. Ionizing radiation includes gamma rays,
Although radiation beams and the like may also be used, electron beams are most preferably used because continuous irradiation is easy, the apparatus is compact, and operation is easy.

As an electron beam, irradiation with an energy of 100 KeV to 3 MeV at a dose of 3 to 30 Mrad is
This is preferable in view of the grafting rate of the vinyl monomer, dyeability and texture of the product, which will be described later. Examples of electron beam sources include Kotscroft-Walton type, Van de Graaff type, resonant transformer type, insulated core transformer type,
Various electron beam accelerators are used, such as linear type, dynamitron type, and high frequency type. In order to irradiate cloth with an electron beam, a method is adopted in which a spot beam is scanned at high speed or a continuous curtain-like beam is irradiated from a linear filament. Generally, surface irradiation is performed by continuously moving the object to be irradiated.

Immediately after irradiating the cloth with ionizing radiation, the vinyl monomer is placed in an organic solvent solution or aqueous emulsion bath containing a lower alcohol, acetone, dimethylformamide, aromatic, etc., preferably in a proportion of 10 to 50%. After immersion, it is taken out from the bath and squeezed using a mangle or other squeezing machine to adjust the amount of vinyl monomer liquid impregnated so as to obtain a weight increase of preferably 80 to 120%. The above-mentioned impregnating amount range is such that sufficient vinyl monomer grafted product can be obtained to improve dyeing property.
It is also preferable from the viewpoint of not significantly increasing the amount of homopolymers and unreacted monomers removed after graft polymerization.

Examples of vinyl monomers used include methacrylic acid or acrylic acid such as methyl, ethyl, propyl, n-butyl, isobutyl,
Esters such as t-butyl, and hydrophobic monomers such as styrene and vinyl acetate are preferably used, but water-soluble monomers such as acrylic acid amide and vinyl pyrrolidone may also be used, and the monomers are not necessarily limited to these.

In order to obtain an aqueous emulsion from these hydrophobic monomers, it is preferable to use a nonionic, anionic, or cationic surfactant as an emulsifier.

In accordance with the present invention, the cellulosic fabric thus impregnated is introduced into a heated steam atmosphere,
The fibers are graft-polymerized with the steam-treated and impregnated vinyl monomer. As the heated steam, superheated steam of 105 to 200°C under normal pressure is preferably used. Normal pressure is used because it significantly reduces the need for airtightness of the steamer and facilitates continuous processing with the introduction and removal of the fabric. Furthermore, there is no contamination of acids that inhibit graft polymerization. An example of a normal-pressure steamer that enables continuous treatment of fabrics and high-glast reaction is the TH steamer manufactured by Arioli, an Italian manufacturer. In particular, when superheated steam at 120 to 140°C is used, a stable vinyl monomer grafting ratio can be obtained, and it is also preferable in terms of dyeability and texture of the product.

The cloth after the steam treatment is washed in a solvent and then with water, if necessary, to remove the homopolymer and unreacted monomers attached to the fibers.

Through the above-mentioned series of treatments, a fabric grafted with monomers is generally obtained in an amount of 5 to 100%, preferably 20 to 40%, based on the weight of the fabric.

The fabric treated to improve dyeability as described above (or its sheet material if the textile product is yarn as mentioned above) is brought into contact with transfer paper having a sublimable dye layer, and then heated under pressure. Perform transfer printing process. Examples of sublimable dyes include sublimation-dispersible dyes that are conventionally used for sublimation transfer printing of synthetic fibers such as polyester fibers, acrylic fibers, and polyamide fibers, as well as sublimation-dispersible dyes that can be dyed by adding alkali agents, oxidizing agents, etc. Basic dyes with
Oil-soluble dyes with sublimation properties are used. The transfer printing conditions are not particularly different from general ones.
For example, at a temperature of 180 to 220℃, 100g/cm ² to 3Kg/
Conditions of pressure of cm ² and treatment time of 20-60 seconds are adopted.

In addition, prior to the above-mentioned dyeability improvement treatment, the cloth may be acylated with a monocarboxylic acid anhydride or chloride before irradiation with ionizing radiation, or the cloth may be further treated with glycerin, etc. after being grafted and thoroughly washed with water. It is also possible to obtain a further improvement in dyeability by using a combination of impregnation with a polyhydric alcohol.

As described above, according to the present invention, cellulose-based fiber products, which have conventionally been difficult to dye by sublimation transfer printing, can be
Irradiation with ionizing radiation, impregnation with vinyl monomer liquid,
Continuous graft polymerization through a series of graft polymerization processes under steam treatment improves the dyeability of the sublimable disperse dye, without causing deterioration of physical properties such as hardening of the texture of textile products. It has the advantage of providing durable transfer printed products at low cost. In particular, it is possible to provide a clear and robust transferred pattern even to products blended or woven with synthetic fibers.

Hereinafter, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 A desized and refined broad cotton cloth was irradiated with a 200 KeV electron beam at a dose of 5 Mrad using an electron beam accelerator (manufactured by Energy Science (USA), Electrocurtain), and then immediately placed in a monomer bath with the following composition.
Soaked for 30 seconds.

Methyl acrylate 30 parts Water 70 parts Nonionic surfactant 0.5 parts Next, the cotton cloth after soaking was taken out of the bath and squeezed so that the impregnation rate was 100%. (manufactured by Arioli) and was continuously steamed for 5 minutes to graft-polymerize methyl acrylate.

The thus treated cotton fabric was then washed in a xylene solvent to remove the homopolymer and residual monomers, thoroughly washed with water, and then dried. The grafting rate for this cotton fabric was confirmed to be 30% by gravimetric method.

The cotton cloth treated with the above procedure is then brought into contact with the dye layer of sublimation transfer paper printed with disperse dye (CIDisperse Red 60), and pressed from the transfer paper side with a hot iron at 200°C to create a beautiful red dyed product. was gotten.

Example 2 Polyester/cotton was used instead of the cotton cloth in Example 1.
When the procedure of Example 1 was repeated using a 50/50 blend fabric, the grafting rate obtained was 9%, but a strong dyed product was obtained by the sublimation transfer method using a hot iron. Ta.

Claims (1)

[Scope of Claims] 1 Cellulose-based fiber products are activated by irradiation with ionizing radiation and then impregnated with a vinyl monomer solution, and then the fiber products taken out from the impregnation solution are brought into contact with heated steam to transfer the impregnating monomer to the fibers. 1. A dyeing method for cellulose-based fiber products, which comprises graft polymerizing the product, and then subjecting the thus graft-polymerized fiber product to pressure and heat treatment while in contact with a transfer paper having a sublimable dye layer. 2. The method of item 1 above, wherein the ionizing radiation is an electron beam. 3. Item 1 or 2 above, wherein the vinyl monomer liquid is a mixture of the vinyl monomer and its solvent or an aqueous emulsion of the vinyl monomer.
Section method. 4. The method according to any one of items 1 to 3 above, wherein the heated steam is superheated steam at a temperature of 105° to 200°C under normal pressure, and the textile product is treated with the heated steam for 5 to 30 minutes.