JPH05117565A - Emulsion ink for perforated plate printing - Google Patents

Abstract

PURPOSE:To obtain the subject ink having an arbitrarily adjustable color tone free from color separation, comprising a specific water-in-oil emulsion, by adding a water-soluble colorant to the water phase. CONSTITUTION:The objective ink comprising a water-in-oil emulsion composed of 10-50wt.% oil phase such as liquid paraffin and 90-50 wt.% aqueous phase and a water-soluble colorant (e.g. C. I. Direct-Yellowl) in the aqueous phase. Pigment (e.g. furnace carbon black) is preferably contained in the oil phase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emulsion ink for stencil printing, and more particularly to an emulsion ink for stencil printing whose color tone can be arbitrarily adjusted.

[0002]

2. Description of the Related Art A stencil printing method uses a stencil printing base paper as is well known, and by moving ink from one side of the base paper to the other side through a perforation portion formed by making a plate on the base paper, Printing is performed on the surface of an object to be printed such as paper. Generally, the color tone adjustment of printed matter with ink is
This is done by adding pigments of other colors.
However, in this case, the pigment to be combined is not only a desired color tone, but, for example, depending on the combination thereof, color separation may occur, and a uniform color tone or image may not be obtained, so that considerable attention should be paid to the selection. Need.
In addition, a pigment and a dye may be simultaneously added to the oil phase, but the oil that can be used in the water-in-oil emulsion ink does not contain a non-volatile component when it is allowed to stand on a printing machine. Since it has to be done, there is a disadvantage in that the printed matter is fringed by the dye and oil of the image over time.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks of the prior art and to provide an emulsion ink for stencil printing in which the color tone is adjusted.

[0004]

The emulsion ink for stencil printing of the present invention comprises an oil phase of about 10 to 50% by weight and an aqueous phase of about 9% by weight.
It is characterized by comprising a W / O type emulsion consisting of 0 to 50% by weight and containing a water-soluble colorant in the oil-water phase.

In order to achieve the above-mentioned object, the present inventors have
As a result of various studies, in the water phase of the water-in-oil emulsion,
It was confirmed that by adding a colorant, an ink having no color separation and a color tone adjusted can be obtained. The present invention has been made on the basis thereof.

The present invention will be described in more detail below. The oil phase is composed of a pigment, an oil component, an emulsifier, a resin, and the like, and the water phase is composed of water, a water-soluble resin, an electrolyte, a fungicide, an antioxidant, a water evaporation inhibitor, and the like. Known constituents which do not inhibit the formation of emulsion are used as these constituents.

As the oil component in the oil phase used in the present invention, conventionally known ones can be applied, for example, liquid paraffin, spindle oil, light oil, kerosene, machine oil, mineral oil such as lubricating oil; olive oil, rapeseed oil. Vegetable oils such as castor oil and soybean oil are used. Also, synthetic oils can be used in the present invention. When using synthetic oils, various compounds are available. Representative synthetic vehicles are polyisobutylene, polyisobutenes, hydrogenated polydecenes, trimethylolpropane esters, neopentyl esters and pentaerythritol esters, di (2-ethylhexyl) sebacate, di (2-ethylhexyl) adipate, dibutyl phthalate. , Fluorocarbons, silicic acid esters, silanes, esters of phosphorus-containing acids, liquid urea, ferrocene derivatives, hydrogenated synthetic oils, chain polyphenyls, siloxanes and silicones (polysiloxanes), butyl substitution Examples thereof include alkyl-substituted diphenyl ethers represented by bis (p-phenoxyphenyl) ethers and phenoxyphenyl ethers.

The emulsifier used in the present invention is preferably a nonionic surfactant such as sorbitan higher fatty acid ester, polyoxyethylene sorbitan higher fatty acid ester, fatty acid monoglyceride, fatty acid diglyceride and higher alcohol, alkylphenol, fatty acid and the like. Ethylene oxide adduct, etc., and one or a combination of two or more of these having different HLBs is used to prepare a highly stable emulsion.

The pigment that may be contained in the oil phase is
Examples thereof include organic and / or inorganic pigments such as furnace carbon black, lamp black, cyanine blue, cyanine green, lake red, titanium oxide and calcium carbonate.

A suitable amount of resin is added to the oil phase for the purpose of improving the stability of emulsion ink over time and improving the binding property of the ink to paper. Examples of such a resin include alkyd resin, rosin-modified alkyd resin, polymerized castor oil, rosin, polymerized rosin, hydrogenated rosin, rosin ester, hydrogenated rosin ester, terpene resin, petroleum resin, rosin-modified phenol resin, maleic acid. Examples thereof include resins and rubber derivative resins.

As mentioned above, the emulsion ink for stencil printing of the present invention is free from color separation, and in order to obtain a toned ink, it is preferable that the aqueous phase contains a colorant. It is a feature of.

The colorants usable in the present invention include:
Of the common dyes, direct dyes, acid dyes, and basic dyes, those soluble in water, such as C.I. I. Direct
Yellow1, C.I. I. Direct Blue2,
C. I. Basic Yellow2 C.I. I. Acid
Yellow 17 and so on. Also, tannin iron-based and C.I. I. Acid Blue22
Alternatively, a combination of 93 can be used.

As the evaporation inhibitor and anti-caking agent, polyhydric alcohols such as ethylene glycol, sorbitol and glycerin, and polyethylene glycol are used.
Examples of the antiseptic / antifungal agent include aromatic hydroxy compounds and chlorinated compounds thereof, salicylic acid, phenols, p
-Methyl oxybenzoate, ethyl p-oxybenzoate, etc., sorbic acid, dehydroacetic acid, etc. are used.

The emulsion ink for stencil printing of the present invention can be produced, for example, by adding an emulsifier to the oil component and mixing it, and then adding a solution of an aqueous phase to the mixture to emulsify the mixture.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The parts here are based on weight.

Example 1 Oil phase (coloring pigment) Furnace carbon black 4 parts (solvent) # 30 motor oil 21 parts (emulsifier 1) sorbitan sesquioleate 4 parts (emulsifier 2) polyoxyethylene sorbitan monolate 2 parts in water phase (Water) Ion-exchanged water 56 parts (Colorant) Tannic acid / iron gallate ink 0.74 parts C.I. I. Acid Blue22 0.06 part (antifreeze agent) ethylene glycol 12 parts (antiseptic and fungicide) ethyl p-oxybenzoate 0.2 part While stirring, the mixture was emulsified to obtain an emulsion ink for stencil printing. This ink was used for printing with a commercially available heat-sensitive stencil printer (manufactured by Ricoh Co., Ltd., Preport SS955). The stability of the ink was evaluated by the presence or absence of oil stains after being stored in a constant temperature bath at 60 ° C for 1 week. The results are summarized in Table 2
Shown in.

Examples 2 and 3, Comparative Examples 1 and 2 According to the formulation of Table 1, stencil printing inks were prepared in the same manner as in Example 1 and further evaluated in the same manner. The evaluation results are summarized in Table 1.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

According to the emulsion ink for stencil printing of the present invention, by containing a coloring agent in the aqueous phase,
There is no color separation and a toned ink can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumiaki Arai, Inc. 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company, Ricoh Co., Ltd. (72) Masahiro Koike, 1-3-6 Nakamagome, Ota-ku, Tokyo Shares In Ricoh Company (72) Inventor Hitoshi Ueda 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh (72) Inventor Naoto Shimoda 1-3-3 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh ( 72) Inventor Takashi Sugawara, 3-1, Shinmei, Nakameisei, Shibata-cho, Shibata-gun, Miyagi Prefecture Tohoku Ricoh Co., Ltd. (72) Keisuke Asada, 3-1, Shinmei-cho, Shibata-machi, Shibata, Miyagi, Tohoku Ricoh Co., Ltd. Within

Claims (2)

[Claims] 1. An oil phase of about 10-50% by weight and an aqueous phase of about 90-.
It consists of a water-in-oil emulsion consisting of 50% by weight,
An emulsion ink for stencil printing, wherein the water phase contains a water-soluble colorant. 2. The emulsion ink for stencil printing according to claim 1, wherein the oil phase contains a pigment.