Direct phase inversion technology of the hottest a

2022-07-30
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In order to obtain new formulations of organic pigments with excellent dispersibility, high coloring intensity and bright color, which are suitable for printing ink coloring, in addition to adding effective dispersants, such as rosin acid or other additives, in the synthesis process or post-treatment process to improve the particle surface polarity of the product, and to prepare powdered products suitable for oil-based offset printing ink; A more effective preparation process is to use the conventional water squeezing phase inversion technology (pushing prcess) to transfer the water containing filter cake and resin connecting material (ink blending oil) from the water phase to the oil phase in the presence of a specific surfactant, separate the water, dehydrate the water to make the base ink product, and finally use it to produce printing ink

basf company introduced in the U.S. patent U.S. (1981) the technology of water-based pigment slurry extrusion phase conversion for benzidine pigments, Lake Red C and copper phthalein; The principle is that the synthetic aqueous pigment slurry (with a solid content of at least 2%, or a high solid content of 50%) is filtered, and the phase transformation process of the pigment is completed by using the special water extrusion phase transformation equipment for the next step. The schematic diagram of the continuous water extrusion phase transformation equipment for the color slurry is as follows:

the aqueous pigment is loaded into the mixing pump body through the feeding port (1), and then enters the mixing pump body through the meter (3) and the conduit (5), At the same time, the connecting material (inking oil) is added from the population (11) through the meter and mixed in the mixer. Due to the shear force exerted by the twin-screw kneader (27, 29), the phase conversion process is completed, the moisture is removed under the vacuum condition, and the qualified color paste is continuously prepared

it can be seen that the continuous phase conversion technology recommended in the patent has the characteristics of saving time, reducing energy consumption and simplifying operation, but it must have a special water squeeze phase conversion reaction equipment

the phase conversion technology in this paper aims to simplify the process without the above-mentioned special equipment, and has better practical characteristics; This technology is to add resin binder to the reaction mixture through the synthesis of aqueous pigment slurry, and directly carry out the phase transformation process of the pigment under stirring. Taking C.I. Pigment Red 53:i and the inner surface guide (golden red C) of the oil cylinder as an example, CLT acid diazotization is coupled with 0-caiphenol to generate barium salt lake, and then the phase transformation is carried out, The process is as follows:

preparation process of base ink: the synthesized G.I. pigment red 53:1 aqueous lake pigment suspension material is added to a stirred reactor (5T) while hot. At a specific temperature, while stirring at a high speed, the ink mixing oil is slowly added. At this time, the pigment particles transfer to the organic phase (ink mixing oil), forming fine (about LMM) colored ink particles, and the water is quickly separated; After the phase transformation, stop stirring, put the colored ink particles into the filter tank, filter out most of the mother liquor water, transfer the ink particles into the water extruder, add water to stir, wash away the water-soluble salt wax, and steam away a small amount of residual water with the help of heating, so as to prepare the base ink of Lake red C. the one-time treatment amount is equivalent to 100 kg of dry powder pigment

it should be pointed out that the content of the added resin oil must be strictly controlled during the phase transformation process. When the amount is insufficient, it can not ensure that all the pigments in the aqueous medium are transferred to the oil phase, and the water separation is not complete; If it is too much, it is easy to cause the paste to agglomerate and meet the innovative needs of customers in the wire and cable industry, which is not easy to discharge

the test results and mass production show that the production process of direct water extrusion and phase transformation from the synthetic pigment slurry has many advantages: for example, the function introduction of the horizontal tensile testing machine for wind power anchor bolt: simplifying the production process; Omit filter press and drying equipment; Shorten the production cycle; Improve working conditions; No need for physical labor such as high temperature and dust; Save manpower; Reduce energy consumption, improve the internal quality of products, and increase the competitiveness of this type of organic pigments

information source: dyes and dyeing

(author/liulinduan Tianjin ink factory)

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