JPH0455627B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing powder colored polymers. The powder colored polymer of the present invention is useful as a coloring agent for inks, paints, wood products, paper, fibers, and the like.

[Prior art] A method for obtaining a colored polymer in powder form involves dyeing a polymer obtained by emulsion polymerization or solution polymerization, and removing the polymerization solvent from the colored polymer by spray drying, flash drying, vacuum drying, etc. There are known methods such as a method of making a powder, or a method of pouring a colored polymer solution into a large amount of a colored polymer insolvent to precipitate it and making it into a powder. However, the former method requires a large amount of energy to remove the solvent;
Moreover, the disadvantage is that free dyes that have not been dyed and inorganic salts that are by-produced during dyeing remain in the powdered colored polymer, and it is difficult to obtain colored polymers with good transient properties and large particle sizes in the latter method. However, it is difficult to economically produce powder colored polymers.

Furthermore, when attempting to obtain a colored polymer powder by dyeing using the water-soluble polymer shown in JP-A No. 60-11542, the polymer contains hydrophilic groups such as hydroxyl groups and amide groups. Therefore, the above-mentioned method was necessary because it did not precipitate as particles.

[Problem that the invention seeks to solve]

An object of the present invention is to provide an economically advantageous method for obtaining a colored polymer in the form of powder, which does not contain free dyes or by-product inorganic salts.

[Means for solving problems]

The gist of the present invention is to apply a basic dye to an aqueous solution containing up to 20% by weight of alcohol of a copolymer of one or more ethylenically unsaturated sulfonic acids or salts thereof and one or more hydrophobic unsaturated monomers. By adding and dyeing, the colored polymer is precipitated as particles,
The purpose of this process is to separately obtain a powder colored polymer.

The details will be explained below.

The ethylenically unsaturated sulfonic acid or salt thereof used in the production of the colored polymer of the present invention includes:
For example, unsaturated sulfonic acids such as styrene sulfonic acid, vinylbenzyl sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, acroyloxyethyl sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and the like; salts, such as lithium salts, sodium salts,
Examples include potassium salts and ammonium salts.

Hydrophobic unsaturated monomers that can be copolymerized with these include methacrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and ethylhexyl methacrylate; methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate; Acrylic acid alkyl esters such as ethylhexyl acrylate; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate; other styrene,
Examples include acrylic, nitrile, butadiene, chloroprene, vinyl chloride, and vinylidene chloride. Unsaturated monomers with hydroxyl groups such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate; unsaturated monomers with amide groups such as acrylamide, methacrylamide, N-methylolacrylamide, and N-methylolmethacrylamide Colored polymers copolymerized with monomers and unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and maleic acid are not preferred because they become tar-like and do not precipitate as particles.

If the composition ratio of ethylenically unsaturated sulfonic acid or its salt in the copolymer becomes too low, it may be reduced to 20% by weight.
The solubility in aqueous solutions containing the following alcohols decreases, and if it becomes too high, the dyeing rate of the dye decreases, so it is usually selected to be 5 mol% or more and 70 mol% or less, preferably 10 mol% or more and 50 mol% or less.

The polymer in the present invention can be prepared by, for example, adding these monomers in water or an aqueous alcohol solution,
Each component is combined together, partially or in combination with a common radical polymerization initiator, for example, a persulfate such as potassium persulfate or ammonium persulfate, or an organic peroxide such as kyumene hydroperoxide or t-butyl hydroperoxide. It can be obtained by introducing the polymer into a polymerization vessel under stirring and polymerizing it.

Polymerization can be carried out below the boiling point of the medium. The molecular weight of the polymer obtained by such a polymerization method depends on the concentration of each monomer present in the polymerization system, the amount of radical polymerization initiator used, the polymerization temperature, etc. The monomer concentration can be freely selected, but generally 3~
50% by weight, usually 10-30% by weight. Polymerization at high concentrations is not preferred because the viscosity of the polymerization system becomes high and it becomes difficult to remove the heat of polymerization. Furthermore, polymerization at too low a concentration is not preferred for economic reasons.

For the purpose of the present invention, there are no restrictions on the method of producing such polymers.

Next, the polymer obtained by polymerization is dyed with a basic dye. Any of triphenylmethane type, azo type, methine type, oxazine type and anthraquinone type may be used.

Dyeing is carried out by adding an aqueous dye solution to an aqueous polymer solution containing 20% by weight or less of alcohol. The dissolved polymer is dyed and precipitates as a colored polymer. Although a sufficiently transient product can be obtained as is, it is necessary to continue heating at 40 to 80℃.
When heated, the colored polymer aggregates and a colored polymer with a larger particle size is obtained. The heating temperature varies depending on the polymer skeleton and the type of dye, but if it is too high, aggregation will proceed too much and the whole will become a lump, so it is not preferable.

The pH during dyeing is determined by the stability of the dye,
Adjust the pH to 2 to 7, preferably 3 using an organic acid such as formic acid, acetic acid, butyric acid, tartaric acid, or malic acid, or an inorganic acid such as hydrochloric acid or sulfuric acid, or using an aqueous solution such as sodium hydroxide or sodium carbonate.
It is desirable to carry out at ~5.

The alcohol concentration in the dyeing system is usually selected to be 0 to 20% by weight, preferably 0 to 10% by weight. If the alcohol concentration is too high, the dyed polymer becomes tar-like or has a small particle size, which significantly impairs the dyeability, which is not preferable.

Examples of the alcohol used include monohydric alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol; and polyhydric alcohols such as ethylene glycol, diethylene glycol, and propylene glycol.

The colored polymer precipitated by this dyeing method is separated using a centrifuge, filter press, etc., and the attached moisture is dried using a normal drying method.
A powder colored polymer of the invention can be obtained.

[Effect]

The reason why the polymer in the present invention dissolves in an aqueous solution containing 20% by weight or less of alcohol, and the reason why it precipitates as particles after being dyed with a basic dye is that the sulfonic acid group with strong hydrophilicity in the polymer is 20% by weight or less. This is because the polymer is contained in an amount sufficient to dissolve in an aqueous solution containing less than 1% alcohol, and the sulfonic acid groups in the polymer make an ionic bond with the basic dye, making it hydrophobic and making the entire polymer hydrophobic, making it difficult to dye. This is thought to be because it is precipitated as particles from the system.

Furthermore, since the colored polymer precipitated as particles is obtained separately, undyed free dye and inorganic salts produced as by-products during dyeing are removed together with the liquid.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a colored polymer containing no free dye or by-product inorganic salt can be economically advantageously obtained in the form of a powder. Furthermore, colored polymers can be obtained that take advantage of the richness and vividness of colors possessed by basic dyes.

〔Example〕

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited in any way by the description of these Examples.

Example 1 In a nitrogen stream, 7 g of water and 13 g of ethyl alcohol were charged into a polymerization vessel, and the temperature was raised to 70°C while stirring.

Butyl methacrylate 85.1g, spinomer
18.7 g of NaSS (sodium P-styrene sulfonate, purity 80.3% by weight, manufactured by Toyo Soda Kogyo Co., Ltd.) was added to water.
Sodium styrene sulfonate aqueous solution and 5.0 g of azobisisobutyronitrile dissolved in 130 g
Polymerization was carried out by adding dropwise a catalyst solution prepared by dissolving 241.3 g of ethyl alcohol over a period of 3 hours. Subsequently, polymerization was continued at 70°C for 5 hours to obtain a solution (65% by weight aqueous ethyl alcohol solution) with a polymer concentration of 20% by weight. The obtained polymer is purified and
Sulfur was determined to be 2.3% by weight by the Zieniger flask combustion method, and the copolymerization composition of sodium styrene sulfonate in the polymer was 10.7% by mole based on the sulfur content.

Next, add 210g of water to 50g of this polymer solution,
After making a 10% by weight ethyl alcohol aqueous solution, 2.9 g of cationic dye Cachilon Yellow 5GLH Conc (manufactured by Hodogaya Chemical Industry Co., Ltd.) and 15 g of acetic acid were added to 100 g of water while stirring.
When dyeing was carried out by gradually adding a solution dissolved in g, the dyed polymer (colored polymer) was precipitated.
PH4.0 using 20% by weight sodium hydroxide aqueous solution
After that, stirring was continued for 30 minutes at 50°C. The particle size of the colored polymer was measured using a Coulter counter and was found to be 130μ on average.

The precipitated colored polymer was filtered through a 5-10μ glass filter and further dried to obtain 12.0 g of powdered colored polymer. The yield was 99% by weight.

The chloride ions in the powdered colored polymer were analyzed by ion chromatography to quantify the chloride ions, which are the counterions of NaCl and free dye, which are produced as by-products during dyeing, but no chloride ions were detected. In addition, the colored polymer was subjected to Soxhlet extraction using water, but the color did not come out.

Example 2 Under a nitrogen stream, 20 g of water was charged into a polymerization vessel, and the temperature was raised to 90°C while stirring. Ethyl methacrylate 30.6
g and 50 g of butyl methacrylate, spinomer
Polymerization was carried out by dropping a sodium styrene sulfonate aqueous solution in which 24.9 g of NaSS (purity 80.3% by weight) was dissolved in 324.5 g of water and a catalyst solution in which 1.0 g of ammonium persulfate was dissolved in 49 g of water over a period of 3 hours. Subsequently, polymerization was continued at 90° C. for 2 hours to obtain an aqueous solution with a polymer concentration of 20% by weight. Example-1
Sulfur was determined in the same manner as 3.1% by weight,
The copolymer composition of sodium styrene sulfonate is
It was 13.6 mol%.

A 10% by weight polymer aqueous solution prepared by adding 50 g of water to 50 g of the obtained polymer aqueous solution was added with a cationic dye Catilon Blue CD-FRLH (Hodogaya Chemical Industry Co., Ltd.).
When dyeing was carried out by slowly dripping a dye aqueous solution prepared by dissolving 5.0 g of the product (manufactured by the company) in 100 g of a 10% by weight acetic acid aqueous solution, a blue colored polymer precipitated. After adjusting the pH to 4.5 using a 20% by weight aqueous sodium hydroxide solution, at 60℃
Stirring was continued for 30 minutes. The average particle size of the colored polymer is
It was 82μ.

The precipitated colored polymer was filtered through a 5-10μ glass filter and dried to obtain 13.2 g of powdered colored polymer. The yield was 97.0%. The colored polymer was extracted by Soxhlet extraction with water, but the color did not come out.

Example 3 Ethyl acrylate 70 in a polymerization vessel in a nitrogen stream
g, 2-acrylamido-2-methylpropanesulfonic acid 30g, ethyl alcohol 240g, water 160g
When the temperature reached 70°C, we started dropping a catalyst solution in which 1g of azobisisobutyronitrile was dissolved in 50g of ethyl alcohol, and polymerization was carried out while dropping for 3 hours. Polymerization was continued for 3 hours to obtain a solution with a polymer concentration of 18.1% by weight. Sulfur was quantified in the same manner as in Example-1.
The copolymerization composition of 2-acrylamido-2-methylpropanesulfonic acid was 17.1 mol%.

Next, 148 g of water was added to 55 g of this polymer solution (64 wt% ethyl alcohol aqueous solution) to make a 15 wt% ethyl alcohol aqueous solution, and the mixture was stirred while stirring. Dyeing was carried out by gradually adding an aqueous dye solution prepared by dissolving 10 g of acetic acid in 100 g of water.

The precipitated red colored polymer had an average particle size of 68 μm, and was filtered through a 5-10 μm glass filter and dried to obtain 14.1 g of powdered colored polymer. The yield is
It was 95.3%.

The colored polymer was extracted with water, but the color did not come out.

Example 4 In a nitrogen stream, 7 g of water and 13 g of ethyl alcohol were charged into a polymerization container, and the temperature was raised to 70° C. while stirring.

60 g of butyl methacrylate and 20 g of propyl methacrylate, spinomer NaSS (sodium P-styrene sulfonate, purity 80.3%, Toyo Soda Kogyo
Polymerization was carried out by adding dropwise an aqueous solution of sodium styrene sulfonate (24.9 g of the product manufactured by Co., Ltd.) in 129.5 g of water and a catalyst solution of 5 g of azobisisobutyronitrile dissolved in 240.6 g of ethyl alcohol over a period of 3 hours. . Subsequently, polymerization was continued at 70° C. for 6 hours to obtain a solution with a polymer concentration of 20% by weight. The sulfur content determined in the same manner as in Example 1 was 3.1%, and the copolymerization composition of sodium styrene sulfonate was 14.3 mol%.

Ethyl alcohol was removed from 50 g of the resulting polymer solution using an evaporator, and water was added to make a 10% by weight aqueous polymer solution. This was a homogeneous aqueous solution. Next, add the cationic dye Cachilon Blue 5GH Conc (Hodogaya Chemical Industry Co., Ltd.) to this polymer aqueous solution.
Co., Ltd. and 10 g of acetic acid dissolved in 150 g of water was gradually added for dyeing. 10% by weight
After adjusting the pH to 4.0 using an aqueous sodium hydroxide solution, stirring was continued at 50°C for 40 minutes.

The precipitated blue colored polymer was filtered through a 5-10μ glass filter and dried to obtain 13.1 g of powdered colored polymer. The yield was 98.1%. The colored polymer was extracted with water, but the color did not come out.

Comparison row 1 The same procedure as in Example 1 was carried out except that hydroxyethyl methacrylate was used in place of the butyl methacrylate used in Example 1. The colored polymer obtained was tar-like and could not be washed. Ta.

Comparative Example 2 The same procedure as in Example 1 was carried out except that acrylamide was used in place of the butyl methacrylate used in Example 1. The colored polymer obtained was tar-like and could not be filtered.

Comparative Example 3 The same procedure as in Example 1 was performed except that methacrylic acid was used in place of the butyl methacrylate used in Example 1, but no colored polymer was precipitated.

Claims (1)

[Scope of Claims] 1. A base is added to an aqueous solution containing 20% by weight or less of alcohol of a copolymer of one or more ethylenically unsaturated sulfonic acids or salts thereof and one or more hydrophobic unsaturated monomers. 1. A method for producing a powder colored polymer, which comprises precipitating the colored polymer as particles by adding a color dye and dyeing. 2. The method for producing a powder colored polymer according to claim 1, wherein the copolymer contains 5 mol% or more and 70 mol% or less of ethylenically unsaturated sulfonic acid or its salt. 3 Hydrophobic unsaturated monomers include methacrylic acid alkyl esters, acrylic acid alkyl esters, vinyl esters, styrene, acrylonitrile,
A method for producing a powder colored polymer according to claim 1, which is butadiene, chloroprene, vinyl chloride, or vinylidene chloride.