JPS61255965A - Method for distincting and preventing fluorescence of optically brightened base material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of quenching or preventing fluorescence in optically whitened substrates.

Optical brighteners are known to absorb invisible ultraviolet light and re-emit it in the blue or fringe region of the visible spectrum. The re-emitted light hides undesirable yellow hues in fibers or other substrates, so the optically whitened material appears whiter to the eye than the untreated material, and the optical brightener are used in large quantities to improve the whitening effect of substrates such as textiles, paper, leather, coatings, pigments, etc.

Nevertheless, the presence of optical brighteners may be undesirable. For example, when optically brightened fiber materials are further dyed or printed with dyes, The overall effect is that in daylight lighting,
It results from the adsorption of the dye used and, in addition, the fluorescence of the optical brightener. When such dyeings or prints are exposed to artificial light substantially free of ultraviolet light, no fluorescence appears and a strong change in hue is perceptible to the viewer.

Accordingly, the present invention provides a method for at least partially eliminating an optical brightening effect created on a substrate by an optical brightener or for creating an optical brightening effect on a substrate by an optical brightener. This method provides a method for preventing
contacting the substrate with an ultraviolet absorber and then fixing the ultraviolet absorber onto the substrate, both steps occurring either before or after treatment of the substrate with the optical brightener. be exposed.

The term "ultraviolet absorber" refers to light near the ultraviolet range (<40
0 nm, especially from 250 to 350 nm) without any obvious re-emission at longer wavelengths. The term "optical brightening effect" as used herein primarily refers to the fluorescent effect of optical brighteners.

Suitable UV absorbers include benzotriazole derivatives, for example 2-(2'-hydroxyphenyl) such as 2-(2'-hydroxy-3'-tart-butyl-5'-methylphenyl)-5-chlorobenzotriazole. ) benzotriazole derivatives, benzophenone ma1 bodies, such as 4-chloro-2゜2',4'-)dihydroxybenzophenone, 2゜2',4-trihydroxybenzophenone, 2゜4-dihydroxy-4'-methoxybenzophenone, 2.2',4.4'-tetrahydroxybenzophenone, 2.4-dihydroxybenzophenone or 2
-2' such as hydroxy-4-methoxybenzophenone
, 2-hydroxybenzophenone derivatives optionally further substituted at the 4', 4 and/or 5 positions,
Benzoic acid derivatives, such as resorcinol monobenzoate, salicylic acid esters, such as 4-CI-1□alkylphenyl salicylate, dibenzoylbenzene derivatives, such as p-di(4-hydroxysalicyloyl)
benzene or 2,4-dibenzoylresorcinol,
Such UV absorbers, including α-cyanoacrylic acid ester derivatives and benzylidene malodinitriles, are known and are described, for example, in U.S. Pat.
3241, German Patent Publications 1101437 and 121
3407 and British Patent No. 796003.

According to the invention it is also possible to use mixtures of UV absorbers.

The UV absorber is advantageously applied from an aqueous medium. Depending on their solubility in water, they can be used as aqueous solutions or in the form of emulsions or dispersions in aqueous media. Emulsions are advantageously prepared by dissolving the UV absorber in an organic solvent, for example white spirit, and adding the resulting solution to water, preferably in the presence of an emulsifier. Preferred emulsifiers are nonionic emulsifiers, such as EVA, C@-tO alcohol % C4~, 3-alkyl substituted phenols, C1-3° fatty acids or oxyalkylation products, preferably ethoxylation products, of castor oil.

Preferably, the nonionic emulsifier contains 5 to 50, more preferably 5 to 30 ethyleneoxy units. As already mentioned, the UV absorbers can also be used in the form of finely divided aqueous suspensions, optionally in the presence of dispersants. Suitable dispersants are those used for dispersing disperse dyes, for example lignin sulfonates or formaldehyde naphthalene sulfonic acid condensation products.

UV absorbers can be processed by exhaustion, impregnation and Residence for 30 minutes to 48 hours depending on the residence temperature at temperatures from 20 to 90 °C, impregnation and treatment with saturated steam, superheated steam at 160 to 190 °C or hot air at 160 to 220 °C or treatment in radiofrequency or thermal contact. It can be applied to the base material by. The ultraviolet absorber can also be used in known textile printing methods,
For example, thermal printing in combination with organic polymers,
For example, it can also be applied by oil- or water-based surface coatings or pigment printing.

The method used for application and fixation of the UV absorber and the amount of UV absorber used depend on the substrate to be treated,
It depends on the optical brightener used, the properties of the UV absorber and the type of dye, if used. Generally, good extinction properties are obtained when the UV absorber is used in an amount of 0.1 to 5% by weight relative to the weight of the substrate.

According to the invention, UV absorbers may be applied to optically whitened substrates. In a preferred embodiment, the UV absorber is applied before, during or after dyeing or printing of the optically brightened material, in particular after dyeing or printing. The UV absorber may also be applied to the substrate before optical brightening of the substrate is carried out; in a preferred embodiment, the UV absorber is applied to the substrate before dyeing or printing with a dye.
applied to unwhitened material during or after.

The dyeing or printing method used for the treatment of the UV absorber is not critical, as long as the dye used and the dyeing or printing conditions are compatible with the UV absorber used.

Today, optical brighteners are often included in household detergents. When dyed or printed clothing is washed with such detergents, the hue changes after drying, especially in the case of light colored dyeings and prints such as yellow and beige. Such disadvantages are prevented by treating the dyed or printed products with UV absorbers according to the invention and washing in a subsequent step with household detergents containing optical brighteners.

According to the invention, the brightening effect of the optical brightener is completely or partially eliminated or clearly reduced on the surface of the substrate. Accordingly, the UV absorber may be partially applied to the optically brightened material or to the material to be optically brightened by printing according to the desired pattern, and when exposed to UV light, it is treated according to the invention. The material has a fluorescent pattern,
For example, it shows patterns for use in theaters or dance clubs or for safety signals.

The method of the invention can be used in various classes of optical brighteners, such as household detergents, detergents or bleaches for the pretreatment of cellulosic fibers or other natural or synthetic fibers, or in paper or synthetic It is used to prevent or eliminate the whitening effect produced by anionic, cationic or dispersion type optical brighteners, such as those used to optically brighten fibers in raw materials. Examples of optical brighteners whose whitening or fluorescent effects are eliminated or reduced according to the invention are bis-(triazinylamino)stilbenedisulfonic acid, triazolyl derivatives of stilbenesulfonic acid, bisstilbene compounds, pyrazoline derivatives,
Naphthalimide, aminocoumarin, oxacyanine, oxazole, benzoxazole or bis-(benzimidazolyl) derivative.

The method of the present invention can be used on any type of material that can be optically brightened, such as textiles, wool or leather. Textile fibers may be in any conventional form such as yarn, woven or knitted fabrics, or non-woven fabrics. Examples of fibrous substrates include wool, cotton, linen, silk, synthetic polyamide, polyester, cellulose acetate or triacetate, polyacrylonitrile, polyvinyl chloride or polyolefin fibers or blends thereof.

It may be advantageous to carry out preliminary tests in order to select UV absorbers that are particularly effective for the substrate to be treated so as to achieve optimal treatment conditions.

Particularly effective UV absorbers for substrates containing polyester fibers (fibers that are or are to be optically brightened) are, for example, UV absorbers of the benzotriazole type, preferably 2-(2'-hydroxy-3'-ter
t-butyl-5'-methylphenyl)-5-chlorobenzotriazole.

In a preferred embodiment of the invention, the UV absorber is incorporated into an optically brightened substrate, in particular the optical brightener is incorporated into the spinning mixture when the fiber substrate comprises synthetic fibers. or applied to a textile substrate as applied in a pre-treatment stage, for example a bleaching process. It is also advantageous to apply UV absorbers to such materials after the dyeing or printing process, which involves dye fixation. The method of the invention is particularly suitable for treating textile materials including synthetic fibers, especially polyester fibers. The UV absorber is selected to eliminate or prevent, preferably completely, the optical brightening effect of optical brighteners used on such synthetic fibers. In the case of polyesters, the UV absorber used to eliminate or prevent the optical brightening effect of the dispersible optical brightener is preferably a benzotriazole derivative.

The invention is further illustrated by the following examples. In the examples, temperatures are given in degrees Celsius and parts and percentages are given by weight.

Example 1: 1000 optically brightened polyester yarns as raw materials
Processed in a cheese and corn dyer with an aqueous bath containing per part:

2-(2'-hydroxy-
3'-tert-butyl-5'-methylphenyl)-5
- chlorobenzotriazole, 0.5 part ammonium sulfate, and 0.3 part glacial acetic acid.

The liquor ratio was 30:1. The temperature of the treatment bath was increased to 40℃ in 40 minutes.
° to 125 °. The yarn was then treated at 125° for 30 minutes. After cooling, the yarn was rinsed and prepared for dyeing.

When exposed to ultraviolet light, the treated yarn showed no fluorescence.

Example 2 C, 1, Fluorescent Brighteni
A 100% polyester fabric that had been optically whitened in advance by thermosol method using ng Agent 330 was printed in a striped pattern with a printing paste containing the following per 1000 copies.

2-(2'-hydroxy-3' in the form of a 4 part aqueous dispersion)
-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 400 parts of guar (Inda
lca H735, Cesalpin1a-Hercu
les S, A, Bergamo, Italy) and as much water as necessary to make a total of 1000 parts.

After drying, the printed fabric is heated with superheated steam at 175° for 7 days.
Processed for minutes. The fabric was then rinsed with warm water, then cold water, and finally dried.

When exposed to ultraviolet light, the printed fabric displayed dark stripes on a bright white bluish background.

Example 3 C, 1, Pluorescent Brighteni
0.5 weight based on the weight of a polyamide knitted fabric prepared by dissolving a 66 polyamide knitted fabric optically whitened in advance by a thermosol process using ng Agent 328 in white spirit and emulsifying it in water with an oleic acid polyglycol ester. % of 2-hydroxy-4-n-octoxybenzophenone was used.
Treated for 30 minutes at H5. After finishing the treatment, the knitted fabric was rinsed with cold water.

When exposed to ultraviolet light, the treated knitted fabric showed no fluorescence.

Example 4 The procedure of Example 3 was repeated, but now 2-hydroxy-
4-n-octoxybenzophenone emulsion to 2-
It was changed to a 0.5% aqueous solution of hydroxy-4-methoxybenzophenone-5-sulfonic acid. The fluorescence of the 66-bolyamide knit was virtually eliminated.

Example 5 C,1,Fluorescent Brighteni
Polyacrylonitrile fibers, optically brightened beforehand by exhaustion using ng Agent 340, containing 1% by weight of 2,2'-dihydroxy-4,4-dimethoxybenzophenone, based on the weight of the fabric in the form of an aqueous dispersion. A bath was used at 98° and pH 6 for 60 minutes.

After treatment, the fabric was rinsed with hot and then cold water.

Upon exposure to ultraviolet light, the treated fabrics exhibited clearly reduced fluorescence.

Example 6 A knitted fabric made from PA66 textured yarn was treated with 0.1% Dye C,1, Acid Orange 1 in a bath ratio of 1:15.
45 and 1.0% sodium 2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5-sulfonate and adjusted to pl (4,5) with acetic acid.

The above percentages are based on the dry weight of the knitted fabric.

The temperature of the bath was increased from 60” to 98” at a heating rate of 1°C/min.
°, with constant mechanical stirring, then 98 °C.
Staining was continued for an additional 30 minutes at °C. Next, knit 50”
Rinse with water, then rinse with cold water, then rinse at 80°
It was dried.

The dyed material was washed with 3 g/l of a commercially available household detergent for thin lichen (W).
ollana@, registered trademark, Eseea AG, Switzerland)
using a bath ratio of 30:l at 40° for 30 minutes,
It was then rinsed and dried. No noticeable change in hue was observed compared to the unwashed knitted fabric.

The knitted fabrics were dyed according to the procedure described above but without the presence of benzophenone derivatives (UV absorbers) and then washed with the same household detergents under the same conditions as above. Compared with the unwashed knitted fabric, the washed knitted fabric showed an obvious hue change.

Claims (1)

[Scope of Claims] 1. At least partially eliminates the optical brightening effect created on the substrate by the optical brightener, or eliminates the optical brightening effect created on the substrate by the optical brightener. A method for preventing whitening effect, comprising the steps of contacting a substrate with an ultraviolet absorber and then fixing the ultraviolet absorber on the substrate, both of which are combined with optical whitening of the substrate. A method characterized in that it is carried out either before or after treatment with an agent. 2. The method according to claim 1, wherein the ultraviolet absorber is selected from benzotriazole derivatives, benzophenone derivatives, benzoic acid derivatives, salicylic acid esters, benzoylbenzene derivatives, α-cyanoacrylic acid ester derivatives, and benzylidene malodinitrile. 3. The UV absorber is 2-(2'-hydroxyphenyl)
Benzotriazole derivatives, 2-hydroxybenzophenone derivatives (which may be further substituted in the 2', 4', 4 and/or 5 positions), resorcinol benzoates, 4-C_1_-_1_2 alkylphenyl salicylates, p- 3. The method of claim 2, wherein the di(4-hydroxysalicyloyl)benzene and 2,4-dibenzoylresorcinol are selected from. 4. The ultraviolet absorber is 2-(2'-hydroxy-3'-t
ert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 4-chloro-2,2',4'-trihydroxybenzophenone, 2,2',4-trihydroxybenzophenone, 2,4-dihydroxy- 4'-
4. The method of claim 3, wherein the method is selected from methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxybenzophenone. 5. Claims 1 to 4, wherein the ultraviolet absorber is used as an aqueous solution or in the form of an emulsion or dispersion.
The method described in any of the paragraphs. 6. A method according to any of claims 1 to 5, wherein the UV absorber is applied to the substrate by exhaustion, impregnation or printing techniques. 7. The method according to any one of claims 1 to 6, wherein the ultraviolet absorber is applied to an optically whitened substrate. 8. A method according to any of claims 2 to 6, wherein the UV absorber is applied to the substrate before the optical whitening of the substrate is carried out. 9. A method according to any of claims 1 to 8, wherein the UV absorber is applied before, during or after dyeing or printing the substrate. 10. The method according to any one of claims 1 to 9, wherein the substrate is textile fiber, paper or leather. 11. The method according to claim 10, wherein the base material is a fiber base material containing polyester, polyamide, or polyacrylonitrile.