JP2003073581A - Base composition for pigment dispersion and dispersing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an ink having a tinting power comparable or superior to a surface-treated pigment by using a phthalocyanine blue free from surface treatment without lowering the productivity of the ink and provide a composition of a dispersion base for the production. SOLUTION: A dispersion base containing phthalocyanine blue free from surface treatment and vegetable oils, etc., is prepared beforehand and the base is dispersed and kneaded with a kneader, etc. The wetting of the pigment with vegetable oil and vehicle improves the dispersibility of even an untreated pigment. The pigment is easily dividable into fine particles and finely dispersed in the vehicle to get a necessary sufficient tinting power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dispersing phthalocyanine blue which has not been surface-treated in a vehicle for producing a printing ink, and a dispersing base composition suitable for the method.

[0002]

2. Description of the Related Art Phthalocyanine blue, which is used as a pigment for printing ink and is commercially available, is generally agglomerated to have a particle size of about 40 to 50 μm. It is necessary to finely disperse the pigment particles that have been aggregated into.

In the production of printing inks, a pigment and a vehicle are first mixed and sufficiently stirred to prepare a uniformly mixed base. This mixing operation is also called premixing because it is a preparation for the next kneading process. The base created is called a distribution base.

After the premixing, the dispersion base is kneaded using a roll mill or a media type kneading machine to finely disperse the pigment in a vehicle and wet the surface of the pigment well with the vehicle. A beads mill as a media type kneading machine,
A sand mill, a ball mill, etc. are mentioned.

In the subsequent step, varnish, solvent, auxiliary agent, etc. are added to the base after the kneading, and the resulting product ink is sufficiently stirred and mixed so as to be uniform.

In the premixing or kneading process, the pigments may aggregate to form coarse particles. When the pigments agglomerate, the ink density decreases and the commercial value of the product decreases. Further, when coarse particles are contained in the ink product, problems such as settling of the particles and accumulation of particles on the plate surface during printing to cause plate residue occur. In order to prevent this aggregation, the surface of pigment particles is treated with a surfactant, a resin such as rosin, or a copper phthalocyanine derivative.

In premixing, some or all of the pigment and vehicle are blended and mixed well with stirring to form a base for dispersion. This base has almost the same particle size of the pigment and is not finely pulverized, and the coloring power of the pigment is very low. The low tinting strength means that even if the same pigment mass concentration is used, the color development is weak and the color is light.

Next, the dispersion base is dispersed and kneaded by a kneading machine or the like to finely pulverize and disperse the pigment, and the pigment is wetted with a vehicle and wrapped. As a result, the coloring power of the pigment is increased and the color is deepened.

The surface-treated phthalocyanine blue has good wettability with the vehicle, good dispersibility, and is easily pulverized with a kneading machine to obtain a necessary and sufficient coloring strength. However, the surface-treated product is expensive.

Phthalocyanine blue that has not been surface-treated is inexpensive, but has strong cohesiveness, and it is difficult to obtain the coloring power of the pigment in the usual dispersion and kneading process. In order to obtain the required coloring strength, a roll mill must be repeatedly kneaded through 4 to 5 times, resulting in a problem of low productivity.

[0011]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention A method and a method for producing an ink having a coloring power equal to or higher than that of a surface-treated pigment from a phthalocyanine blue which has not been surface-treated as a raw material without lowering productivity. It is an object to provide a dispersion base composition for use.

[0012]

In the present invention, a dispersion base containing phthalocyanine blue which has not been surface-treated and vegetable oil or the like is prepared, and the base is dispersed and kneaded by a kneading machine or the like. There is. By first wetting the pigment with vegetable oil or the like and the vehicle, the dispersibility of the pigment not surface-treated is improved, and the pigment is easily micronized and finely dispersed in the vehicle to obtain a necessary and sufficient coloring power. can get. In the present specification, vegetable oils and / or fatty acid esters are collectively referred to as vegetable oils and the like.

Although vegetable oils and the like are used as raw materials for vehicles, the present inventors have found that the dispersibility of pigments can be improved by adding not only the vehicle and solvent to the dispersion base but also vegetable oils and the like. Has been completed. Among the vegetable oils, the vegetable oil has a particularly high effect of improving the dispersibility of the pigment. Among the fatty acid esters, vegetable oil fatty acid esters are highly effective in improving the dispersibility of the pigment.

A suitable mass concentration of phthalocyanine blue in the dispersion base is about 20 to 45%. If the concentration is higher than this range, the fluidity will decrease and the base will become hard,
Difficult to put in a kneading machine. On the other hand, if the concentration is lower than this range, there is little room for adjustment by adding a vehicle or a solvent in the subsequent step, and it becomes difficult to adjust to an appropriate quality.

Any vegetable oil can be used as long as it is commonly used as an ink raw material. Examples include oils such as soybean oil, linseed oil, tung oil, castor oil, dehydrated castor oil, corn oil, safflower oil, and canol oil, and synthetic oils. In the present invention, these vegetable oils may be used alone or in combination of two or more.

Among the above-mentioned vegetable oils, flaxseed oil and soybean oil are preferably used in view of quality such as drying property and stability of availability.

The vegetable oil fatty acid ester used in the base composition for dispersion according to the present invention includes linseed oil fatty acid methyl ester, linseed oil fatty acid ethyl ester, linseed oil fatty acid propyl ester, linseed oil fatty acid butyl ester, soybean oil fatty acid methyl ester. Soybean oil fatty acid ethyl ester, soybean oil fatty acid propyl ester, soybean oil fatty acid butyl ester, palm oil fatty acid methyl ester,
Palm oil fatty acid ethyl ester, palm oil fatty acid propyl ester, palm oil fatty acid butyl ester, castor oil fatty acid methyl ester, castor oil fatty acid ethyl ester, castor oil fatty acid propyl ester, castor oil fatty acid butyl ester, tall oil fatty acid butyl ester, etc. To be

Among the above-mentioned vegetable oil fatty acid esters, soybean oil fatty acid methyl ester and soybean oil fatty acid butyl ester are preferably used.

In order to disperse the dispersing base in the kneaded meat, an ordinary kneading machine such as a roll mill or a bead mill can be used. Media type kneading machines such as bead mills are much easier to perform continuous and automated processing than roll mills.
Suitable for improving productivity.

If the dispersion base of the present invention is allowed to stand for a while (referred to as aging) before being subjected to the dispersion step, the wetting of the pigment with the vegetable oil or the vehicle is improved and the dispersibility is improved. For example, the processing time of the kneading process can be shortened. Although it is effective just to leave it, the effect of improving the dispersibility is further enhanced by stirring. 50-8 during aging
It is also effective to improve the dispersibility by heating and keeping the temperature at about 0 ° C. The aging time is preferably about 6 hours to 1 day, and even if it is left for a longer time, the improvement in dispersibility is small.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described below. First, phthalocyanine blue that has not been surface-treated is mixed well with vegetable oil or the like so that the pigment is sufficiently wrapped with the vegetable oil or the like. After that, the vehicle such as varnish and solvent contained in the ink is mixed to make a dispersion base.

Mixing and premixing of phthalocyanine blue which has not been surface-treated with vegetable oil or other vehicle is carried out using a general stirring mixer such as a dispersion stirring machine.

The composition of the dispersing base is designed so that the viscosity and fluidity are suitable for the meat processor used.

When the amount of vegetable oil or the like is small, it may be added at the same time as the vehicle or solvent. However, vegetable oil or the like has almost no effect of improving dispersibility even if it is contained in a vehicle in a form of being cooked and dissolved, so that it is necessary to add a single vegetable oil or the like.

In the design of the composition of the base, for example, when kneading with a roll mill, it is often preferable that the viscosity of the base is high, it has tackiness, and the fluidity is low. For this purpose, a large amount of vehicle is generally added.

When a media type kneading machine such as a bead mill is used, it is often preferable that the viscosity of the base is low, the tackiness is low, and the fluidity is high. For this purpose, a large amount of solvent is generally added.

A suitable mass concentration of phthalocyanine blue, which has not been surface-treated, in the dispersion base is about 30 to 45%. After dispersing and kneading the base, in order to increase the degree of freedom of the vehicle used for dilution in the commercialization in the subsequent process, the viscosity and fluidity of the base should be within the range that can be processed by the kneading machine, and the pigment concentration in the base Should be as high as possible.

The mass ratio of the phthalocyanine blue which has not been surface-treated and the vegetable oil or the like is 100 when the phthalocyanine blue which is not surface-treated is 100 and the vegetable oil or the like is 1
It is preferably 5 to 40 in order to wrap the pigment well in vegetable oil or the like. When the amount of vegetable oil or the like is 15 or less, the phthalocyanine blue is not sufficiently dispersed, and the coloring power of the pigment is insufficient. When the vegetable oil or the like is 20 to 25, the best result is obtained in terms of dispersibility.

As the vegetable oil and the like, those commonly used as a raw material for ink can be used. Among them, soybean oil and linseed oil are particularly effective in improving dispersibility.

A suitable temperature for premixing is 70 to 120 ° C. Agitation and mixing time is 30 for the entire premixing.
~ 60 minutes.

After the completion of the premixing, the base is allowed to stand for 6 to 24 hours to improve the wetting of the pigment.
The dispersibility is improved, and the productivity of the next kneading process can be increased. It may be said that aging is carried out by leaving it for a while like this. 50-80 during aging
By heating and maintaining the temperature at about ℃, it is possible to enhance the aging effect such as improving the wetting of the pigment. Since the dispersion base of the present invention contains vegetable oil or the like, the content of volatile organic compounds is 5 to 10% lower than that of the conventional one, and the aging effect can be improved by heating at a higher temperature during aging. It can be higher than anything. In addition, stirring during aging or circulating with a pump to promote mixing is also effective in improving the aging effect. However, even if it is allowed to stand for 24 hours or more or aged, almost no further effect is obtained. Further, it is not preferable to leave it for too long because it lowers the operating rate of the manufacturing equipment.

The premixing-completed dispersing base is passed through a kneading machine to finely disperse the pigment and finely disperse it in a vehicle.

As the kneading machine, it is possible to use a general device used in the production of printing ink. A media type kneading machine such as a roll mill, a bead mill or a sand mill is used. In general, a dispersion base for a media type mill can have a higher pigment mass concentration than a base for a roll mill. For example, a base for a roll mill has a limit of about 40% by mass of pigment, but a base suitable for a media type meat grinder can increase the pigment to about 45% by mass. In particular, when vegetable oil fatty acid ester is added as a raw material to be added to the base for dispersion, it is possible to improve the wettability of phthalocyanine blue which has not been surface-treated and at the same time increase the fluidity of the base, which is suitable for a media type meat grinder. A highly fluid dispersion base can be created.

It is difficult to obtain a sufficient effect of dispersing and kneading the roll mill by passing it once only, and it is often necessary to pass it 4 to 5 times. When the number of passes is increased, the coloring power of the pigment is increased but the productivity is decreased. Media type kneading machine can be used by selecting the media to be used and adjusting the filling rate of the media.
A necessary and sufficient degree of dispersion can be easily obtained by one-time kneading.

[0035]

EXAMPLES Examples will be described below. Table 1 shows six dispersion-based formulations of Examples A, B and Comparative Examples C-F according to the present invention. The numerical value of the compound shows the mass ratio when the whole is 100.

[0036]

[Table 1]

As for A to D in Table 1, as the phthalocyanine blue, Fast Gen Blue 5380E manufactured by Dainippon Ink and Chemicals, Inc. is used. This pigment is not surface treated. Fast Gen Blue 5320 is used for E and F. This pigment is surface-treated. As soybean oil, soybean salad oil manufactured by Nisshin Oil Co., Ltd. is used.

As the vehicle, a rosin-modified phenolic resin varnish for lithographic offset ink is used. A compounding example of the varnish used in this example is shown below. Becca Site F-731
0 (manufactured by Dainippon Ink and Chemicals, Inc.) 48 parts, soybean oil 25 parts, AF-6 (manufactured by Nisseki Mitsubishi Corp. industrial lubricant oil) 26 parts, aluminum chelate 1 part.

AF-6 from Mitsubishi Nisseki Co., Ltd. is used as the solvent.

After thoroughly stirring the six types of bases shown in Table 1 to uniformly mix them, Examples A and B and Comparative Examples C and E are kneaded by a media type bead mill. The beads mill uses a horizontal mill manufactured by Asada Iron Works Co., Ltd., and the dispersion medium has a diameter of 2 m.
m zirconia beads are used. The bead mill is passed once to complete the meat. Comparative Examples D and F are kneaded by a roll mill. The roll mill passes through the dispersion base 5 times to knead the meat.

Table 1 also shows the results of evaluating the dispersibility and the coloring power of the pigments for the six types of bases that have undergone kneading and dispersion.

The dispersibility is 4. in JIS K5701-1.
It measures by the method by the grind meter described in 3.2. How to read is judged when three consecutive stripes appear,
Read the scale at that position. The scale of the glide meter is 10 when the groove is deepest at 25 μm, and is 0 when the depth is zero, and is divided into 10 equal parts. For example, in the case of the scale 5, the groove depth is 12.5 μm, and if streaks start to appear there, the particle size is approximately 12.5 μm. It can be said that the smaller the value, the smaller the particle size and the better the dispersibility.

The evaluation of the coloring strength was carried out by thoroughly mixing and mixing 6 g of 2 g of the completely dispersed base and 98 g of white ink (Carton Self 709 White from Dainippon Ink and Chemicals, Inc.) and kneading them. An ink is prepared, and the base ink (referred to as white diluted base) is used to evaluate the tinting strength by spatula according to the following procedure.

In this embodiment, the coloring power (DA) of the base A is used as a standard and the value is set to 100. As an example of obtaining the coloring power (DC) of the base C with respect to the base A, both of the mass concentrations are 30%. A has a higher concentration in the base diluted 50 times with white. That is, the color is dark. Then, the white ink Xg is further added to the white diluted base A so that the density is made equal to that of the base C. At this time, the following equation holds.

[0045]

[Equation 1] Since DA = 100, DC is calculated by the following equation.

[0046]

[Equation 2] In the case of Base C, since 32.7 g of white ink was added to Base A and the densities were the same, the coloring power of Base C is 75 according to formula (2).

The method for evaluating the color difference (apparent density difference) due to spatula drawing is described in the Color Material Engineering Handbook edited by the Color Material Association.
II-III Printing ink 5.1.2 Printing ink test method
(8) According to the method described in (ii).

[0048]

INDUSTRIAL APPLICABILITY According to the present invention, an inexpensive phthalocyanine blue which is not surface-treated can be used to obtain an ink having a coloring power equal to or higher than that of the surface-treated one.
Further, the productivity is equal to or higher than that of the surface-treated product.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kyohei Matsutake             Park 1-4-1, Shozusawa, Itabashi-ku, Tokyo             Heights Shodosawa 803 F-term (reference) 4J039 AB04 AB05 AE02 AF01 BC20                       BC60 BE01 BE12 BE22 CA04                       EA16 GA02

Claims (6)

[Claims] 1. A base composition for dispersion containing phthalocyanine blue which has not been surface-treated and vegetable oil and / or fatty acid ester. 2. The mass ratio of phthalocyanine blue which has not been surface-treated in the dispersion base is 20 to 45.
%, And the mass of vegetable oil and / or fatty acid ester is 15 when the mass of the phthalocyanine blue is 100.
The base composition for dispersion which is ˜40. 3. A base composition for dispersion according to claim 1, wherein the vegetable oil is flaxseed oil or soybean oil. 4. A dispersing base composition according to claim 1 or 2, wherein the fatty acid ester is a vegetable oil fatty acid ester or an animal oil fatty acid ester. 5. A method for producing a printing ink base, which comprises dispersing the dispersion base according to claim 1 with a media type kneading machine. 6. Mixing for improving the wetting of the pigment for 6 to 24 hours after the premixing by blending the dispersing base according to any one of claims 1 to 4 and before the kneading step. Alternatively, a method for producing a base for a printing ink, which comprises performing a stationary treatment.