JPS61238876A - Emulsion ink - Google Patents

Abstract

PURPOSE:To obtain an emulsion ink which has excellent transferability to paper even when light printing is conducted and has a good printing effect, by adding a maleinized wax or its derivative to an emulsion ink contg. an oil component and an aq. component. CONSTITUTION:The titled ink is obtd. by blending a maleinized wax or its derivative with a printing emulsion ink contg. an oil component such as pigment, mineral oil, resin, etc. and an aq. component such as water, alcohol, etc. The maleinized wax or its derivative can be obtd. by maleinizing wax such as paraffin wax, microcrystalline wax or polyethylene wax, or neutralizing the maleinized wax with an alkali or alkaline earth metal, ammonia or amine.

Description

[Detailed description of the invention] "Purpose of invention" (Industrial application field) The present invention relates to emulsion ink.

More specifically, the present invention relates to an emulsion ink suitable for use in letterpress printing and flexographic printing for newspapers and books.

(Prior Art) Normally, oil-based ink used in letterpress printing etc. is partially dispersed in the air in the form of particles or filaments due to centrifugal force and static electricity in the rollers of the printing press. The so-called misting phenomenon contaminates printing machines and printed matter, or has a negative impact on printing workers.

In addition, the oil-based inks normally used in letterpress printing, etc. are made of colorants, mineral oils, vegetable oils, synthetic resin vehicles, natural resin vehicles, or mixtures thereof, so they are flammable and have a high burnout calorie content. Especially in the case of low viscosity ink of 100 voids or less, there is a great risk of fire because it is in a completely liquid state, and it falls under the category of dangerous goods under the Fire Service Act.

Furthermore, since ordinary oil-based inks do not have very good affinity with paper, the transferability from the 9th plate to the paper is not sufficient, and the image quality of the printed matter is not smooth. Also, after printing.

The low viscosity vehicle in the oil-based ink, mineral oil, penetrates the paper and shows the image on the other side. This causes so-called strike-through or strike-through phenomena, which deteriorates the image quality of printed matter.

Among these drawbacks, emulsion inks have been developed to prevent misting and the risk of fire, but in general emulsion inks, the water-based component is mainly alcohol, and even when water is used, the emulsion is not stable. If the water content is insufficient or the water content is low,
There was nothing that fully satisfied both effects.

In addition, although the emulsion ink shown in JP-A-55-5946 using a nonionic activator with HLB of 7 to 13 can prevent misting and fire hazards, it has problems with transferability, strike-through, etc. A sufficient effect was not obtained in terms of image quality. Furthermore, JP-A No. 5, which uses an amine salt or alkali metal salt of wax oxidation product acid as an emulsifier.
Emulsion inks disclosed in Japanese Patent No. 8-8970 and the like are known. In other words, emulsion inks using oxides of mineral waxes or neutralized products of the oxides have a strong odor characteristic of wax oxides, which may worsen the printing environment, or if wax oxides with low odor are used, emulsion inks may Ink stability and fluidity suitable for printing are insufficient.

(Problems to be Solved by the Invention) In order to solve the above problems and obtain excellent printed matter, the inventors of the present invention have conducted intensive research and created an emulsion ink using maleated wax or its derivatives. This reduces odor.

It has been found that an ink that is free from misting and fire hazards can be obtained. It also has excellent transferability to paper even with light printing pressure, and has little bleed-through or strike-through.

We have created an emulsion ink with good print effects.

``Structure of the Invention'' (Means for Solving the Problems) The present invention provides a printing emulsion ink containing an oily component such as a pigment, mineral oil, or resin, and an aqueous component such as water or alcohol, in which a maleated wax or This is an emulsion ink characterized by containing the derivative thereof.

Maleated waxes or derivatives thereof used in the present invention are maleated waxes such as paraffin wax, microcrystalline wax, and polyethylene wax, or maleated waxes that are neutralized with alkali metals, alkaline earth metals, ammonia, amines, etc. This is what happens.

Maleation is generally an addition reaction of wax with maleic anhydride through a radical reaction and/or a thermal addition reaction (ene reaction) to a non-conjugated double bond.

To explain an example of a maleation reaction, when maleic anhydride is added to polyethylene wax (for example, polyethylene wax has one bond), and heated and stirred at 150°C or higher while adding an organic peroxide, a radical reaction occurs and the polyethylene wax has one bond. Maleic anhydride is added to the double bond to obtain a maleated polyethylene wax.

Sara adds maleic anhydride to paraffin wax,
When the mixture is heated and stirred at 150° C. or higher while adding an organic peroxide, a radical reaction occurs and a maleated paraffin wax is obtained.

9 For example, if maleic anhydride is added to polyethylene wax and heated and stirred at 200°C or higher in a nitrogen atmosphere,
An ene reaction occurs and maleic anhydride is thermally added to the double bond of the polyethylene wax, yielding a maleated polyethylene.

Furthermore, maleated products of these waxes can also be neutralized to form derivatives.

Among maleated waxes or derivatives thereof prepared by the above method, those having properties in the 9th order range are particularly applicable to the emulsion ink of the present invention.

Hardness and penetration) ^STMD-132110 or above Acid value ASTM D-138650 or above Melting point^STMD-12730~70°C Specific products as maleated products of the above waxes or derivatives thereof 2For example, Nippon Oil's po wax S-
10, 20, 30 (hardness 12-33. acid value 55-90.
melting point 51-66°C).

The reason I go through it is.

1) A maleated wax or a derivative thereof having a hardness of less than 10 may impair the fluidity of the emulsion ink and may also make the emulsion unstable.

2) If the acid value is less than 50, the stability of the emulsion ink will be insufficient, and there will be a drawback that the above-mentioned excellent performance as an emulsion ink cannot be obtained.

3) If the melting point exceeds 70°C, the emulsion ink has poor fluidity and emulsion stability.

In carrying out the present invention, if the maleated wax having the above properties is in liquid form, it may be used as is, or if it is solid, it may be used after being melted and dispersed in mineral oil.

The emulsion ink of the present invention contains pigment and mineral oil.

Oil-based components such as resin, water-based components such as water and alcohol,
This is an ink whose main component is a maleated wax or a derivative thereof. As other components, for example, surfactants, extender pigments, rosin, etc. can be used as required. The composition ratio of emulsion ink is
Based on 100 parts by weight of oily components.

Preferably, the maleated wax or its derivative is preferably 1 to 20 parts by weight, and the aqueous component is 20 to 80 parts by weight.

The method for creating emulsion ink is as an oil-based component.

Mixing 5 to 25 parts by weight of a pigment with 75 to 95 parts of a vehicle in which one or more of mineral oil, drying oil, natural resin, or synthetic resin is dissolved, for example, a resin in mineral oil or drying oil;
Use a mixture that has been ground and dispersed using a sand mill, three rolls, etc.

To 100 parts of this oily component, 1 to 20 parts of the maleated wax or its derivative is thoroughly mixed with a stirrer, and then 20 parts of the aqueous component such as water, alcohol, surfactant, etc.
~80 parts are mixed on a high speed stirrer and emulsified.

An oil-soluble surfactant 1 for the oil component, such as a polyoxyethylene type, sorbitan type, or fatty layer glyceride type with an HLB of 8 or less, and a polyoxyethylene type, alkylbenzene, or alkylnaphthalene type anion with an HLB of 12 or higher for the aqueous component. If a surfactant is used in combination, a more stable emulsion ink can be obtained.

As described above, by using the maleated wax or its derivative according to the present invention, a very stable emulsion ink is cleaved, and when used in rotary letterpress printing, the odor during printing is low.

In addition to exhibiting good printability with little misting, the printed matter has little strike-through and has good transferability to three sheets of paper, providing an effect similar to that of offset printing.

Examples are shown below. In the example, "parts" and "%" refer to parts by weight 9
Indicates weight %.

Example 1 Natural resin vehicle (25% Giltonite, 75% spindle oil) 15 parts High viscosity mineral oil (50-100 Boise petroleum fraction) 100 parts Carbon black 12 parts Prussian blue
2 parts Low viscosity mineral oil (spindle oil) 25 parts or more are kneaded in a sand mill or three-roll kneader, and further mixed with a mineral oil dispersion of maleic wax (PO wax 5-30.50).
%) and stir to mix to make an oily component.

to this.

water
25 parts Demol N (surfactant made from Kao Stone 111a)
Add 1 part and stir with a high-speed stirrer to obtain an emulsion ink.

Example 2 Synthetic resin vehicle (Tamanol 354 (Arayo Kagaku Kogyo)
rosin modified phenolic resin) 40%, linseed oil 35%
, spindle oil 25%) 20 parts high viscosity mineral oil 10 parts phthalocyanine blue ゛ 8 parts low viscosity mineral oil
Mix 25 parts or more, knead with a sand mill or three-roll kneader, and further add mineral oil dispersion of maleic wax (PO wax 5-10
．． Add 15 parts of sorbitan diglycerin fatty acid ester (50% content) and mix with stirring to prepare an oily component.

to this.

water
Add 20 parts and 1 part of polyoxyethylene fatty acid ester and stir with a high-speed stirrer to obtain an emulsion ink.

Example 3 Natural resin vehicle 5 parts high viscosity mineral oil 15 parts carbon blank 10 parts phthalocyanine blue 1 part low viscosity mineral oil
Grind 25 parts or more using a sand mill or three-roll kneading machine, and then grind.

Mineral oil dispersion of maleated wax (containing 5-30.50% PO wax) 7 parts Add 1 part fatty acid monoglyceride,
Stir and mix to make the oily component.

to this.

water
Add 35 parts and 1 part of Demol N and stir with a high-speed stirrer to obtain emulsion ink.

Comparative example Natural resin face 5 parts High viscosity mineral oil 15 parts Carbon black 10 parts Dark blue
1 part low viscosity mineral oil
Grind 25 parts or more using a sand mill or three-roll kneading machine, and then grind.

Add 2 parts of sorbitan diglycerin fatty acid ester and 6 parts of paraffin wax dispersion in mineral oil and mix with stirring to prepare an oily component.

to this.

water 3
5 parts Demol N 1 part was added and stirred with a high-speed stirrer to make emulsion ink, but it thickened during storage and had poor emulsion stability.Therefore, the following printing was not possible. The results of a performance comparison between the rotary letterpress ink and the emulsion ink of Example 1.3 are shown.

Table 1: Comparison between the current rotary letterpress ink and the emulsion ink of the present invention (1) Bluefield viscosity (2) Visual judgment (3) Rub with finger and observe finger stains Table 2 shows the comparison between the currently used rotary letterpress ink and the emulsion ink of the present invention , shows the performance comparison results with the emulsion ink of Example 2.

Table-2 Comparison between current rotary letterpress ink and emulsion ink of the present invention

Claims (1)

[Scope of Claims] 1. An emulsion ink for printing containing an oil component such as a pigment, mineral oil, or resin, and an aqueous component such as water or alcohol, which is characterized by containing a maleated wax or a derivative thereof. ink. 2. For 100 parts by weight of oily component, 1 to 20 parts by weight of a maleated wax or its derivative, and 20 to 20 parts by weight of aqueous component.
The emulsion ink according to claim 1, comprising 80 parts by weight.