JPH0931384A - Emulsion ink for stencil printing - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide an emulsion ink for stencil printing, which improves emulsion stability, ink drying property and ink fixing property, and has little change in ink composition even after being left for a long time and has little plate dryness. To do. SOLUTION: (1) Water in oil having an oil phase and a water phase (W
/ O) type emulsion ink, in the aqueous phase,
An emulsion ink for stencil printing, comprising a water-soluble polymer compound having a tertiary amine.
(2) An emulsion ink for stencil printing, wherein a colorant component is contained in at least one of the oil phase and the water 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 specifically, it has excellent emulsion stability, ink drying property and ink fixing property, and has little plate drying even when left for a long time. The present invention relates to emulsion ink.

[0002]

2. Description of the Related Art In stencil printing, stencil printing base paper is used to make a plate, and ink is passed through the formed perforations to print on a printing medium such as paper. Therefore, it is used in a wide range of fields. Water-in-oil (W / O) type emulsion ink is generally used as a printing ink for stencil printing (JP-A-61-255967, JP-A-64-14284 and JP-A-4-132).
777, JP-A-5-117565, etc.).

The W / O type emulsion ink is dried by permeation of the ink component into the material to be printed and scattering of the volatile solvent in the oil phase and the water component in the water phase. The permeation into the inside of the material to be printed changes depending on the pore state (porous state) of the material to be printed and depends on the type of the material to be printed (lightly coated paper, fine paper, medium-quality paper, etc.). On the other hand, if the scattering of the volatile solvent in the oil phase and the water component in the water phase is accelerated, the drying time of the ink can be shortened, but if the drying is too fast,
There arises a problem that the ink is dried in the pores of the stencil printing base paper and the composition of the ink is apt to change in the ink pool in the plate cylinder of the stencil printing machine. Further, in multicolor printing such as full-color printing, there is a problem that the surface of the printed material is filled with the ink of the first color and it becomes difficult for the inks of the second and subsequent colors to penetrate into the printed material.

A method is known in which a resin having iodination (oxidation polymerization form) is used in a stencil printing ink.
When a large amount of this resin is used in ink, it causes problems such as drying and solidification of ink in the hole portion of the stencil printing base paper and the ink pool portion in the plate cylinder of the stencil printing machine as described above. Absent. For these reasons,
In the past, it was not possible to dry the ink quickly, and the ink transferred to the printing material was not completely fixed on the surface of the printing material depending on the printing, and the ink spreads to other parts when rubbed with a finger etc. However, there is a problem in that it is impossible to obtain a printed material that is true to, and the fingers and the like are soiled.

Further, it has been conventionally known that a water-soluble polymer compound is added to the water phase of a W / O type emulsion ink. In such a W / O type emulsion ink, when the ink is transferred to a printing material such as paper, the oil phase component, which is the outer phase of the emulsion, first penetrates into the printing material.
Then, the aqueous phase, which is the internal phase, permeates and / or scatters inside the paper, so that the aqueous phase component is likely to remain on the surface of the material to be printed, and there is an advantage that a film can be formed on the ink transfer portion. However, when the water-soluble polymer compound is dissolved in the water phase of the W / O type emulsion ink, there is a drawback that the emulsion stability is inferior to the case where it is not used (Japanese Patent Publication No. 44-2165). ).

[0006]

The object of the present invention is to solve the above-mentioned problems of the prior art and to improve the stability of emulsions.
It is an object of the present invention to provide an emulsion ink for stencil printing, which has improved ink drying properties and ink fixing properties, has little change in ink composition even after being left for a long time, and has little plate drying.

[0007]

The inventions claimed in this application are as follows. (1) A water-in-oil (W / O) type emulsion ink having an oil phase and a water phase, wherein the water phase contains a water-soluble polymer compound having a tertiary amine. Emulsion ink for printing. (2) An emulsion ink for stencil printing, wherein at least one of the oil phase and the aqueous phase described in (1) contains a colorant component.

In the W / O type emulsion ink, normally,
Since the oil phase component, which is the outer phase, has a low surface tension, the oil phase component penetrates into the material to be printed before the water phase component, and then the water phase component permeates and / or scatters. In the W / O type emulsion ink of the present invention, the aqueous phase component cannot penetrate into the inside of the printing medium in which the oil phase component has permeated, and the water phase component is accumulated on the surface of the printing medium, and water or the like is accumulated on the surface. Evaporate. Due to this evaporation, the water-soluble polymer compound in the aqueous phase component forms a film, and the ink is dried on the surface of the printing object, and the ink is not significantly affected by the surface state (pore state) of the printing object. Will be dried.

Further, since this water-soluble polymer compound forms a film and is completely fixed to the object to be printed, the printing ink does not spread to the area other than the area where it is transferred, even if it is rubbed with a finger or the like.
A printed image that is faithful to the original can be obtained and does not transfer to a finger or the like. Furthermore, since the W / O type emulsion ink of the present invention uses a water-soluble polymer compound having a tertiary amine in the aqueous phase, the collapse of the emulsion is suppressed and the emulsion stability is improved. Although the reason for this is not clear, it is considered that the polarization of the N (nitrogen) atom contained in the tertiary amine interacts with the surfactant in the outer phase and strengthens the interface film of the emulsion (oil and water). .

The water-soluble polymer compound having a tertiary amine used in the present invention includes one or more water-soluble polymer compounds in the molecule.

Embedded image A compound having a bond such as, for example,

[0011]

Embedded image And the like.

The amount of these water-soluble polymer compounds added is
1-2 in terms of solid content based on the total amount of emulsion ink
0 wt% is preferable, and 3 to 10 wt% is more preferable.
If this addition amount is too large and left for a long time after plate making,
The ink forms a film at the perforated portion on the plate, and if the film becomes thick, the passage of the ink may be blocked, which is not preferable.

Known pigments and dyes are used as colorant components in the emulsion ink of the present invention, and these can be contained in at least one of the oil phase and the water phase of the emulsion. Examples of the pigment include, for example, furnace carbon black, lamp black, for monochrome.
Examples thereof include carbon blacks such as acetylene black and channel black, metals such as copper, iron, titanium oxide and calcium carbonate, and metal oxides. For color, organic pigments such as azo, cyanine, dioxazine, and quinacridone are listed. As the dye, an oil-soluble dye, a water-soluble dye or the like is used.

The aqueous phase component of the emulsion ink of the present invention may contain water-soluble additives such as a wetting agent, an electrolyte, a fungicide, an antioxidant and a water evaporation inhibitor, if necessary. The oil phase component of the emulsion ink of the present invention contains a non-volatile solvent, a volatile solvent, an emulsifier and, if necessary, a resin component. Non-volatile solvents include motor oils, spindle oils, machine oils, mineral oils such as liquid paraffin, vegetable oils such as olive oil, castor oil, and salad oil, and known volatile solvents include mineral oil-based solvents and vegetable oils. A solvent is used. The use ratio of the non-volatile solvent and the volatile solvent varies depending on the mixing ratio of the oil phase and the water phase, but the weight ratio (non-volatile solvent / volatile solvent) is 50 to 50%.
It is preferably in the range of 95/50 to 5.

The emulsifier is used to form a W / O type emulsion, and a nonionic surfactant is preferably used. For example, sorbitan higher fatty acid ester (for example, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan sesquioleate), fatty acid monoglyceride, fatty acid diglyceride, and higher alcohol, Examples thereof include ethylene oxide adducts such as alkylphenols and fatty acids.

As the resin component, alkyd resin, rosin-modified phenol resin, maleic acid resin and the like are used.
These are components necessary for fixing the colorant component to the printing medium such as paper, but, for example, when the colorant is contained in the aqueous phase component, it is not always necessary to add it. The W / O emulsion ink of the present invention contains, for example, 10 to 70% by weight of an oil phase (O) component and 90 to 30% by weight of an aqueous phase (W).
It can be manufactured by gradually adding the components and emulsifying them.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, the part in an example means a weight part. Example 1 A W / O type emulsion ink was produced by the following method with the composition shown in Table 1. First, the alkyd resin, furnace carbon black and sorbitan monooleate were thoroughly stirred and then dispersed with a three-roll mill. afterwards,
After adding # 40 motor oil and No. 4 solvent, sufficient stirring was performed again to prepare an oil phase. Next, polyvinylpyrrolidone (trade name manufactured by BASF,
K30) was heated and dissolved in ion-exchanged water, and ethylene glycol was added to prepare an aqueous phase. While gradually adding the aqueous phase to the oil phase, the mixture was stirred with a stirrer to emulsify.

Examples 2 to 4 Polyethyleneimine (manufactured by Nippon Shokubai Co., trade name Epomin SP-018) as a water-soluble polymer compound and an alkylolamine salt (Big Chemie Japan) in the composition shown in Table 1 were used. Company name, Disperbyk-1
81) and poly N-acroylpyrrolidine were used, respectively, to prepare a W / O type emulsion ink in the same manner as in Example 1.

Example 5 A W / O type emulsion ink was prepared by the following method with the composition shown in Table 1. First, sorbitan monooleate, # 40 motor oil and No. 4 solvent were thoroughly stirred to prepare an oil phase. Next, the carbon black dispersant solution shown in Table 1 (Grand Black AM, manufactured by Mikuni Dye Co., Ltd.)
An aqueous solution prepared by heating and dissolving polyvinylpyrrolidone (trade name, K30 manufactured by BASF Co., Ltd.) in ion-exchanged water was added to −1000 / carbon concentration 37.5%), and ethylene glycol was further added to prepare an aqueous phase. The obtained oil phase and water phase were emulsified in the same manner as in Example 1.

Comparative Example 1 An emulsion ink was prepared in the same manner as in Example 1 except that the composition shown in Table 1 was used. Comparative Examples 2 to 4 Emulsion inks were produced in the same manner as in Example 1 except that the water-soluble polymer compound shown below was used in the composition shown in Table 1.

[0021]

Embedded image

Comparative Example 5 An emulsion ink was prepared in the same manner as in Example 1 except that the composition shown in Table 1 was used. The resin used is in the oxidative polymerization form (resin having iodination). Comparative Example 6 An emulsion ink was produced in the same manner as in Example 5, except that the formulation shown in Table 1 was used.

[0023]

[Table 1]

<Test Example> Examples 1 to 5 and Comparative Examples 1 to 1
After performing stencil printing (manufactured by Lithograph RC115D (registered trademark) Ideal Science Co., Ltd.) using each emulsion ink for stencil printing obtained in 5, stencil printing was performed. The stability of the emulsion of this emulsion ink, and the fixability, dryability, and plate dryability of the obtained printed matter when left for a long time were examined by the following methods, and the results are shown in Table 2.

(1) Emulsion stability: After ink preparation,
The ink was allowed to stand for 1 month at 70 ° C., and the state of ink collapse was visually observed. When the emulsion ink did not collapse, it was evaluated as ◯, and when it collapsed, it was evaluated as x. (2) Fixability: After printing on woodfree paper, evaluation was made by rubbing when rubbing the printed image surface with a finger. When the printed image was not broken even if it was rubbed with a finger, it was evaluated as ◯, and when the printed image was broken and the trace of being rubbed by the ink remained, it was evaluated as x. (3) Dryability: Evaluation was made according to the state of occurrence of set-off when 100 sheets were continuously printed. When the set-off did not occur, it was evaluated as ◯, and when the set-off occurred and the drying property of the ink deteriorated, it was evaluated as x. (4) Plate-drying property: After printing, the used stencil printing base paper was left for 48 hours under the conditions of 23 ° C. and 50 Rh%, and then printing was performed again using this base paper. At this time, an ink film was not formed at the perforated portion of the stencil printing base paper and a printed image that was faithful to the original was obtained, and a case where a faithful image was not obtained was evaluated as x.

From Table 2, Examples 1 to 5 are superior to Comparative Example 1 in fixability and dryness, and in Comparative Examples 2 to 5.
It was found that the emulsion was superior in stability to that of No. 4, and that printing could be continuously performed without causing plate drying even when left for a longer time than Comparative Example 5. Further, from the results of Examples 1 and 5 and Comparative Examples 1 and 6, it is possible to obtain the effect of adding the water-soluble polymer compound having a tertiary amine regardless of whether the colorant component is present in the oil phase or the water phase. Was confirmed.

[0027]

[Table 2]

[0028]

Since the W / O type emulsion ink of the present invention contains a water-soluble polymer compound having a tertiary amine in the aqueous phase, it is excellent in the fixing property and drying property of the ink on the printing medium. Moreover, the stability of the emulsion is excellent.
Further, the W / O type emulsion ink of the present invention is excellent in plate drying property even after being left for a long time, as compared with the case where an oxidative polymerization type resin is added to the oil phase.

[Procedure amendment]

[Submission date] March 22, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

[0023]

[Table 1]

Claims (2)

[Claims] A water-in-oil (W / W) having an oil phase and an aqueous phase.
O) type emulsion ink, wherein the water phase contains a water-soluble polymer compound having a tertiary amine, which is an emulsion ink for stencil printing. 2. An emulsion ink for stencil printing, wherein at least one of the oil phase and the aqueous phase according to claim 1 contains a colorant component.