SU628156A1 - Method of preparing pigments - Google Patents

Description

The invention relates to a technique for producing pigments used for dyeing leather, rubber, plastics. There are known methods for producing pigments used for dyeing leather and plastics by precipitating on inorganic substrates, such as clay, amino resin salts, followed by diazotization and aerial combination of the obtained product or its treatment with direct or acid dyes 1,22. A known method for producing pigments, according to which an aniline-formaldehyde resin is precipitated on an active dispersed mineral, for example benthonite, in an aqueous medium, after which the resulting product suspension is treated with a dye h. A disadvantage of the known methods is the low hiding power of the pigments obtained therewith, which is mainly due to the low adsorption of aniline-formaldehyde resins on dispersed materials in an aqueous medium. The purpose of the invention is to increase the pigment viscous ukr. To achieve this goal, the deposition of the resin by the proposed method is carried out in an organic solvent medium, preferably in / methane le, chloroform or acetone, with a weight ratio of the initial dispersed mineral and solvent 5-50: 1 followed by processing the suspension of the resulting product with a dye. The proposed method allows increasing the hiding power of various colored pigments by 1.3-1.5 times. Example. To 4.65 weight.h. (0.05 M) aniline in 100 weight.h. water while stirring poured 6,2ves.ch. (0.05 M) hydrochloric acid and at 40 ° C add 3.7 wt ... h. {0.05M) 40% formaldehyde. The mixture was kept at a boiling point of 2.5 hours and then reprecipitated with a 30? Solution of sodium hydroxide. The resulting precipitate is filtered off, washed with water, dried and dissolved in a mixture of chloroform and methanol, taken in a weight ratio of 12: 1. The resulting solution of a condensation product based on an aniline-formaldehyde resin is added to the suspension of asangel in an organic solvent containing 20 parts by weight. askangel and

iOO% weight, h chloroform, the mixture is stirred for 5 hours, the precipitate of the obtained organoclay is suspended in 300 ml of water, 86 parts by weight are added. concentrated hydrochloric acid, O 6 weight.h. 2.4 million by weight of methyl dye and diazotized. sodium nitrite at,. The suspension of the diazocompound formed during this process is combined with a solution containing bvesh of anilide acetoacetic acid.

the resulting yellow pigment does not dissolve in water, acid and 5% sodium chloride solution. Pigment dispersion. With a 10% aqueous solution of ammonium caseinate in a ratio of 1: 1 gives an opaque film after drying. Coverage is 32 g / m, 1.3 times as high as pigment pigment, compared with a similar yellow colored pigment.

Example 2. To 6.05 weight-hours (O 05 M) dimetiLanilina poured L 2 weight h (0.05 M) with concentrated hydrochloric acid at and added g; Weight of h. (0,015M) 40% formaldehyde. The reaction mixture is kept at a temperature ", J is cooled, reprecipitated with 30% sodium hydroxide solution, dried and dissolved in acetone.

The resulting condensation solution is added to a suspension of the dispersed mineral, 20 blas. Crimean kila and 200 wt. acetone, and the precipitated organoclay is stirred for an hour and suspended in 200 ml of water;

8 weight .4. concentrated hydrochloric acid and 9 parts by weight dye straight turquoise and durable, soluble in water.

Get the pigment in the form of a blue powder, resistant to water and acid. The pigment opacity is 10 to exceed that of a similar pigment obtained in a known manner.

Improving the quality of the pigment obtained according to the present invention greatly expands the possibilities of its industrial application.

Claims (3)

1. USSR author's certificate No. 258499, cl. C 09 C 1/42, 1/30/1996 2 USSR Author's Certificate No. 305176, KL..S 09 C 3/10, 30. 12.1968 3. USSR author's certificate 1 331077, cl. C 09 C 1 / 42.15.04.1970