CN109867983B - Method for improving nano pigment dispersibility by using metal catalyst - Google Patents

Abstract

The invention belongs to the technical field of material processing, and particularly relates to a method for improving the dispersibility of a nano pigment by using a metal catalyst. The invention achieves the effect of stably dispersing the pigment with the crystal grain of less than 300nm by adding the metal catalytic dispersing agent consisting of the sulfonyl compound and the inorganic chloride salt catalyst into the pigment system. The invention has the advantages of good dispersion effect of the micronized nano pigment, less polymerization and crystallization phenomena, low viscosity, low thixotropy, good coating film gloss, high transparency and simple and convenient preparation of the final nano pigment dispersion liquid, and the nano pigment dispersion liquid can be used for general purposes of gravure ink printing, automobile industry, wood industry and the like, and can also be used for coating the back of a magnetic stripe, ink for an ink-jet printer, ink for a color filter and the like.

Description

Method for improving nano pigment dispersibility by using metal catalyst

Technical Field

The invention belongs to the technical field of material processing, and particularly relates to a method for improving the dispersibility of a nano pigment by using a metal catalyst.

Background

The nanopigment is a fine-grained technical product of pigment or other functional material crystal grains of about several hundred nanometers, and the conventional method for improving the dispersibility of the nanopigment is to add an acrylic polymer and a polyester dispersant, but the effect of improving the dispersibility of the nanopigment is generally worse than that of a fine-grained particle of 300nm or less. On the other hand, when the dispersibility of the nanopigment is lowered, quality problems such as uneven coating, lowered coloring power, lowered glossiness, lowered reliability, lowered conductivity and insulation are easily caused, and thus there is an urgent need in the market for a method for improving the dispersibility of the fine nanopigment.

The Chinese patent with patent publication No. CN102675514A and publication No. 2012.09.19 discloses a preparation method of an aqueous nano pigment dispersion, which comprises the following steps: mixing 2.5-40 wt% of styrene with a distilled polymerization inhibitor, 2.5-20 wt% of acrylate monomer, 0.25-5 wt% of crosslinking monomer, 0.05-0.5 wt% of co-emulsifier and 0.05-0.5 wt% of oil-soluble initiator, adding 0.25-2.5 wt% of organic pigment to be dispersed, and completely dissolving to form an oil phase solution; dissolving 0.05-2 wt% of emulsifier and 0.05-2 wt% of buffering agent in 40-90 wt% of deionized water to form water phase solution; mixing and stirring the oil phase solution and the water phase solution, and homogenizing by ultrasonic to obtain a miniemulsion; and (2) moving the miniemulsion into a reactor, introducing nitrogen, heating to raise the temperature, initiating polymerization, adding an alkali-soluble monomer with the weight percentage of 0.5-5% after the reaction is carried out for 10-40 min, continuously reacting for 1-5 h, cooling to room temperature, adjusting the pH value to 8-10 by using ammonia water, filtering and discharging to obtain the aqueous nano pigment dispersion.

However, the method for preparing the dispersion liquid disclosed in the patent of the invention has a problem that the dispersion liquid mainly contains styrene and an acrylate monomer, and the dispersion liquid has a poor effect of dispersing smaller nano pigment particles, and is not suitable for dispersing fine particles having a particle size of 300nm or less.

Disclosure of Invention

The invention aims to provide a method for improving the dispersibility of a nano pigment by using a metal catalyst, which can achieve the effect of stably dispersing the pigment with the crystal grain of less than 300nm by adding a metal catalytic dispersing agent consisting of a sulfonyl compound and an inorganic chloride salt catalyst into a pigment system. The invention has the advantages of good dispersion effect of the micronized nano pigment, less polymerization and crystallization phenomena, low viscosity, low thixotropy, good coating film gloss, high transparency and simple and convenient preparation of the final nano pigment dispersion liquid, and the nano pigment dispersion liquid can be used for general purposes of gravure ink printing, automobile industry, wood industry and the like, and can also be used for coating the back of a magnetic stripe, ink for an ink-jet printer, ink for a color filter and the like.

The technical scheme adopted by the invention for solving the problems is as follows: the method for improving the dispersibility of the nano pigment by using the metal catalyst sequentially comprises the following steps of:

s1, mixing the micronized nano pigment, the metal catalytic dispersant and deionized water to obtain a primary dispersion liquid;

s2, adding an auxiliary dispersing agent into the primary dispersing liquid to obtain a middle-term dispersing liquid;

s3, carrying out physical dispersion on the middle-stage dispersion liquid to obtain a later-stage dispersion liquid;

s4, heating and preserving heat to the later-stage dispersion liquid to obtain the final nanometer pigment dispersion liquid,

the metal catalytic dispersant comprises an inorganic chloride salt and a sulfonyl compound.

In the present invention, the sulfonyl group in the sulfonyl compound can be effectively adsorbed on the surface of the pigment particles after the fine-sizing and the dispersion thereof is promoted, and the inorganic chloride salt forms ionic complexation with the sulfonyl group in the sulfonyl compound, so that the mutual interference between the sulfonyl compounds can be effectively prevented, and finally, the sulfonyl compound modified by the inorganic chloride salt as the metal catalyst can effectively disperse the nanopigment with crystal grains of 300nm or less, which is not achieved by the acrylic dispersant commonly used in the prior art.

In step S1, the inorganic chloride salt includes one or more of aluminum chloride, zinc chloride, sodium chloride, potassium chloride, and ammonium chloride; the sulfonyl compound comprises one or more of benzene sulfonic acid, p-toluene sulfonic acid and 4-aminobenzene sulfonic acid.

In step S1, the nanopigment is one or more pigment mixtures with crystal grains smaller than 300 nm.

In step S1, the weight ratio of the nanopigment to the sulfonyl compound is 1:0.12-1: 0.15; the weight ratio of the sulfonyl compound to the inorganic chloride salt is 1: 0.63-1: 0.72.

in step S2, the auxiliary dispersant includes one or more of amine dispersant or polyether dispersant, and the weight ratio of the auxiliary dispersant to the metal catalytic dispersant is 0.15:1-0.22: 1.

In step S3, the physical dispersion process sequentially comprises two steps of stirrer pre-dispersion and ultrasonic dispersion machine main dispersion, wherein the rotating speed in the stirrer pre-dispersion process is 400-500rpm, and the time is 40-45 min.

In the main dispersing process of the ultrasonic disperser, the ultrasonic power is 85-100KHz, the temperature of the dispersing liquid is 45-60 ℃, and the dispersing time is 2-2.5 min.

In step S4, the temperature of the heating and heat preservation treatment process is 30-80 ℃ and the time is 18-240 h.

In step S1, the nanopigment includes one or more of anthraquinone, oxazine, DPP, isoindoline, isoindolinone, perylene, perinone, quinacridone, quinophthalone, thioindigo, azo lake, naphthol AS, benzimidazolone, condensed diazo, and phthalocyanine blue.

In step S1, the deionized water may be replaced with an organic solvent capable of dissolving inorganic chloride salts.

The invention achieves the effect of stably dispersing the pigment with the crystal grain of less than 300nm by adding the metal catalytic dispersing agent consisting of the sulfonyl compound and the inorganic chloride salt catalyst into the pigment system. The invention has the advantages of good dispersing effect of the micronized nano pigment, less polymerization and crystallization phenomena, low viscosity, low thixotropy, good luster of a coating film, high transparency and simple and convenient preparation of the final nano pigment dispersion liquid.

Detailed Description

The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Example 1

Step one, 100kg of naphthol AS, 12kg of benzenesulfonic acid, 7.9kg of aluminum chloride and 250kg of deionized water are taken and stirred and mixed uniformly to obtain a primary dispersion liquid, wherein the naphthol AS is subjected to micronization technology treatment in advance, and the crystal grain is 260-285 nm;

secondly, adding 3.2kg of PN245 dispersing agent and propylene glycol block polyether dispersing agent into the primary dispersion liquid, and then uniformly stirring and mixing to obtain middle-stage dispersion liquid;

thirdly, performing stirrer pre-dispersion on the middle-stage dispersion liquid, wherein the rotating speed of the stirrer is 400rpm, the stirring time is 40min, performing ultrasonic dispersion by using an ultrasonic dispersion machine, the ultrasonic power is 85KHz, the temperature of the dispersion liquid is 45 ℃, and the dispersion time is 2min to obtain later-stage dispersion liquid;

and fourthly, heating and preserving heat for the later-stage dispersion liquid, heating to 35 ℃, and preserving heat for 40 hours to obtain the final nano pigment dispersion liquid.

The finally obtained nano pigment dispersion liquid is prepared by a novel dispersing agent with a metal catalyst, and the novel dispersing agent can reduce and relieve the strong polymerization between pigments, so that a high-quality aqueous dispersion is obtained.

In the present invention, various polymers may be added as required, a photosensitive resin may be used, and a solvent other than water may be used, and the organic solvent may be one that ensures effective dispersion of the metal catalyst dispersant.

Example 2

Step one, taking 100kg of pyrene ketone and quinacridone, 13kg of p-toluenesulfonic acid, 9.1kg of aluminum chloride and 250kg of deionized water, stirring and mixing uniformly to obtain a primary dispersion liquid, wherein the naphthol AS is subjected to micronization technology treatment in advance, and the crystal grain is 250-ion-285 nm;

secondly, adding 4.4kg of PN245 dispersing agent and propylene glycol block polyether dispersing agent into the primary dispersion liquid, and then uniformly stirring and mixing to obtain middle-stage dispersion liquid;

thirdly, performing stirrer pre-dispersion on the middle-stage dispersion liquid, wherein the rotating speed of the stirrer is 450rpm, the stirring time is 43min, performing main dispersion on an ultrasonic dispersion machine, the ultrasonic power is 100KHz, the temperature of the dispersion liquid is 55 ℃, and the dispersion time is 2.3min to obtain the later-stage dispersion liquid;

and fourthly, heating and preserving heat for the later-stage dispersion liquid to 65 ℃, and preserving heat for 100 hours to obtain the final nano pigment dispersion liquid.

The finally obtained nano pigment dispersion liquid is prepared by a novel dispersing agent with a metal catalyst, and the novel dispersing agent can reduce and relieve the strong polymerization between pigments, so that a high-quality aqueous dispersion is obtained.

In the present invention, various polymers may be added as required, a photosensitive resin may be used, and a solvent other than water may be used, and the organic solvent may be one that ensures effective dispersion of the metal catalyst dispersant.

Example 3

The first step, 100kg of anthraquinone and oxazine, 15kg of p-toluenesulfonic acid, 10.8kg of aluminum chloride and 250kg of deionized water are taken, stirred and mixed uniformly to obtain a primary dispersion liquid, wherein the naphthol AS is subjected to micronization technology treatment in advance, and the crystal grains are 250-280 nm;

secondly, adding 5.6kg of PN245 dispersing agent and propylene glycol block polyether dispersing agent into the primary dispersion liquid, and stirring and mixing uniformly to obtain middle-stage dispersion liquid;

thirdly, performing stirrer pre-dispersion on the middle-stage dispersion liquid, wherein the rotating speed of the stirrer is 500rpm, the stirring time is 45min, performing main dispersion on an ultrasonic dispersion machine, the ultrasonic power is 100KHz, the temperature of the dispersion liquid is 60 ℃, and the dispersion time is 2.5min to obtain the later-stage dispersion liquid;

and fourthly, heating and preserving heat for the later-stage dispersion liquid to 75 ℃, and preserving heat for 200 hours to obtain the final nano pigment dispersion liquid.

The finally obtained nano pigment dispersion liquid is prepared by a novel dispersing agent with a metal catalyst, and the novel dispersing agent can reduce and relieve the strong polymerization between pigments, so that a high-quality aqueous dispersion is obtained.

In the present invention, various polymers may be added as required, a photosensitive resin may be used, and a solvent other than water may be used, and the organic solvent may be one that ensures effective dispersion of the metal catalyst dispersant.

While the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various modifications can be made within the knowledge of those skilled in the art without departing from the spirit of the present invention. These are non-inventive modifications, which are intended to be protected by patent laws within the scope of the claims appended hereto.

Claims (1)

1. A method for improving the dispersibility of a nano pigment by using a metal catalyst is characterized by sequentially comprising the following steps:

step one, 100kg of naphthol AS, 12kg of benzenesulfonic acid, 7.9kg of aluminum chloride and 250kg of deionized water are taken and stirred and mixed uniformly to obtain a primary dispersion liquid, wherein the naphthol AS is subjected to micronization technology treatment in advance, and the crystal grain is 260-285 nm;

secondly, adding 3.2kg of PN245 dispersing agent and propylene glycol block polyether dispersing agent into the primary dispersion liquid, and then uniformly stirring and mixing to obtain middle-stage dispersion liquid;

thirdly, performing stirrer pre-dispersion on the middle-stage dispersion liquid, wherein the rotating speed of the stirrer is 400rpm, the stirring time is 40min, performing ultrasonic dispersion by using an ultrasonic dispersion machine, the ultrasonic power is 85KHz, the temperature of the dispersion liquid is 45 ℃, and the dispersion time is 2min to obtain later-stage dispersion liquid;

and fourthly, heating and preserving heat for the later-stage dispersion liquid, heating to 35 ℃, and preserving heat for 40 hours to obtain the final nano pigment dispersion liquid.