JPH06172691A - Emulsion ink for mimeographic printing - Google Patents

Abstract

PURPOSE:To provide an ink improving the separation of printed paper from an ink drum when the paper is printed, improving the winding-up of the printing paper, and preventing the generation of the back transfer of the printed ink, because the printed ink is substantially not transferred to the back surface of the next printing paper. CONSTITUTION:The ink comprises a water drop-in-oil type emulsion comprising approximately 10-60wt.% of an oil phase containing a wax component and approximately 90-40wt.% of a water phase. The content of the wax component is preferably 0.5-5wt.% based on the whole amount of the ink, and the wax component preferably has a melting point of 50-120 deg.C.

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 to a water-in-oil type emulsion ink for stencil printing, in which the printing paper is well separated from the ink drum during printing and is not easily transferred back. .

[0002]

2. Description of the Related Art As is well known, a stencil printing method uses a stencil printing base paper, and by moving ink from one side of the base paper to the other side through a perforation portion of the base paper, a printing material such as paper is printed. It prints on the surface. The perforated portion of the stencil printing base paper used for this stencil printing is, for example, a method of applying an impact force like a typewriter base paper, a method of applying a frictional force by a pencil or the like like a wax base paper, or an electric discharge destruction or the like. It is formed by a method of utilizing energy. Since the perforated portion formed by such a perforation method has a relatively small opening area,
In order to achieve the required movement of the ink through the perforated portion, it was necessary to use a relatively soft ink having a high fluidity as the copy ink.

By the way, in recent years, stencil printing base papers using heat-sensitive energy of a flash or a thermal head have been actively produced. The stencil printing base paper made by such a heat-sensitive method has a large hole diameter, unlike the one made by impact force, friction force or electric energy, and therefore, when using a soft copy ink as in the past, it is perforated. Ink excessively passes through the area, so-called "sticking out" or "bleeding" phenomenon occurs, and a clear printed image cannot be obtained. Further, recently, the copying printer has been changed from the two-cylinder type to the single-cylinder type in order to simplify the mechanism and to make the mechanism compact. Due to its mechanism, the two-cylinder type does not supply more ink than necessary to the surface of the base paper, so there is no problem even if soft ink is used. Leaks to the trailing edge of the master and stains the press roller or the printed matter.

As a solution to these drawbacks, there has been proposed a stencil printing ink containing a specific fraction of mineral oil and an oxycarboxylic acid compound (JP-A-63-16).
1064 publication). However, although the ink has a sufficient effect of preventing the ink from squeezing out and bleeding, it has been found to be insufficient in terms of the separation of the printing paper from the ink drum during printing.

[0005]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to improve the separation of the printing paper from the ink drum during printing, to improve the winding of the paper, and to make the printed ink to be printed next time. An object of the present invention is to provide an emulsion ink for stencil printing, which does not easily transfer to the back side of paper and does not cause back slip.

[0006]

According to the present invention, in a water-in-oil type stencil printing emulsion ink comprising about 10 to 60% by weight of an oil phase and about 90 to 40% by weight of an aqueous phase, at least a non-volatile oil or a hard oil is used. There is provided a water-in-oil emulsion ink for stencil printing, characterized in that a wax component is further contained in the oil phase composed of a volatile oil, a colorant, an emulsifier and a resin.

Since the water-in-oil type emulsion ink for stencil printing of the present invention contains a wax component in the oil phase, the release of the printing paper from the ink drum at the time of printing becomes good, and the paper is wound. Since the rise is improved and the printed ink is difficult to transfer to the back of the next printing paper,
There is also very little backsiding.

The present invention will be described in more detail below. The water-in-oil type emulsion ink for stencil printing of the present invention comprises a w / o type emulsion comprising an oil phase of about 10 to 60% by weight and an aqueous phase of about 90 to 40% by weight, and is in a non-volatile oil or a hardly volatile oil. In addition, a wax component is further contained in the oil phase containing at least a colorant, an emulsifier and a resin. The water phase is composed of water, an antifreezing agent, a preservative, a moisturizing agent, and the like.

The blending amount of the wax component contained in the oil phase is preferably 0.5 to 5% by weight based on the total amount of the ink. If the blending amount is less than 0.5% by weight, the effect on paper release and back slipping is often small. Conversely, 5% by weight
In excess, it is good for paper separation and back slipping, but
The fixability may be deteriorated or the mesh of the ink drum may be clogged.

The wax has a melting point of 50 to 1
It is preferable to use one in the range of 20 ° C. Melting point 5
When a wax having a temperature of less than 0 ° C. is used, the effect on paper separation and back slipping is often small, and conversely, the melting point is 1.
When a wax having a temperature of more than 20 ° C. is used, it is effective for paper separation and reverse printing, but the fixing property may be deteriorated or the mesh of the ink drum may be clogged.

Examples of the wax having a melting point in the range of 50 to 120 ° C. include carnauba wax, auricury wax, microcrystalline wax, paraffin wax, ceresin wax, montan wax, candelilla wax, shellac wax, and agar wax. , Beeswax, wood wax, low-content polyethylene, fatty acids such as stearic acid, and waxes such as polyethylene glycol stearate.

As the non-volatile oil or the hardly volatile oil used in the present invention, conventionally known ones can be applied, for example, mineral oil such as liquid paraffin, spindle oil, light oil, kerosene, machine oil and lubricating oil; olive oil, Vegetable oils such as rapeseed oil, castor oil, and soybean oil; dioctyl phthalate (DOP), tricresyl phosphate (TCP), and other esters are used.

As the colorant (coloring pigment), inorganic pigments such as carbon black, red iron oxide, ocher, ultramarine blue and navy blue, and organic pigments such as Hansa yellow, cyanine blue, phthalocyanine blue and chrome fast red are used.
As the emulsifier, known surfactants such as sorbitan fatty acid ester and polyoxyethylene fatty acid ester can be used. Examples of the resin include rosin, rosin-modified alkyd resin, rosin-modified phenol resin, and rosin-modified maleic acid resin.

[0014]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The parts and% shown below are based on weight.

Example 1 (Preparation of varnish) Rosin-modified phenolic resin (Arakawa Chemical Co., Ltd .: Tamanol 361) 25 parts Non-volatile oil (Nippon Oil Co., Ltd .: C machine oil) 70 parts Microcrystal wax 5 parts (Nippon Oil Co., Ltd.) (Production: Micro 180, melting point 84 ° C.) The above composition was heated and dissolved at 200 ° C. to prepare a varnish.

(Preparation of Oil Phase) Carbon black (Mitsubishi Metals Co., Ltd .: MA100) 12 parts Emulsifier (sorbitan sesquioleate) 12 parts Refractory solvent (Exxon Chemical Co .: Isopar L) 10 parts Varnish 66 parts The above composition Was thoroughly kneaded with a three-roll mill to prepare an oil phase.

(Preparation of Aqueous Phase) Water 90 parts Antifreeze 10 parts Preservative 0.01 part The above composition was mixed to prepare an aqueous phase.

(Preparation of Ink) An emulsion ink was prepared by gradually adding 70 parts of an aqueous phase to 30 parts of an oil phase and stirring the mixture. (Wax content 1.0%)

When the printing test was carried out by a stencil printer Preport VT3500 manufactured by Ricoh Co., Ltd., clear printed matter without set-off could be obtained. In addition, paper winding up during printing did not occur after printing 1000 sheets.
When printing was carried out for one week after the printing was completed without using the printing machine for one week, a clear printed matter was obtained without clogging of the drum mesh.

Example 2 (Preparation of varnish) Rosin-modified phenol resin (Arakawa Chemical Co., Ltd .: Tamanol 354) 25 parts Nonvolatile oil (Nippon Oil Co., Ltd .: C machine oil) 60 parts Paraffin wax (Nippon Seiwa Co., Ltd .: 150 parts, melting point 69 ° C.) 15 parts A varnish having the above composition was prepared in the same manner as in Example 1.

An ink was prepared in the same manner as in Example 1 except that the above varnish was used (wax content: 3.
0%). Next, when the ink was used to print with Preport VT-3500 in the same manner as in Example 1, good results were obtained as in Example 1.

Example 3 (Preparation of varnish) Rosin-modified phenol resin (Arakawa Chemical Co., Ltd .: Tamanol 354) 27 parts Non-volatile oil (Nippon Oil Co., Ltd .: C machine oil) 70 parts Montan wax (BASF Co .: OP, Melting point 80 to 95 ° C.) 3 parts A varnish having the above composition was prepared in the same manner as in Example 1.

An ink was prepared in the same manner as in Example 1 except that the above varnish was used (wax content: 0.
6%). Next, when the ink was used to print with Preport VT-3500 in the same manner as in Example 1, good results were obtained as in Example 1.

Example 4 (Preparation of varnish) Rosin-modified phenol resin (Arakawa Chemical Co., Ltd .: Tamanol 361) 5 parts Non-volatile oil (Nippon Oil Co., Ltd .: C machine oil) 70 parts Paraffin wax (Mobile Oil Co., Ltd .: 135) , Melting point 58 ° C.) 25 parts A varnish having the above composition was prepared in the same manner as in Example 1.

An ink was prepared in the same manner as in Example 1 except that the above varnish was used (wax content: 5.
0%). Next, when the ink was used to print with Preport VT-3500 in the same manner as in Example 1, good results were obtained as in Example 1.

Example 5 (Preparation of varnish) Rosin-modified phenol resin (Arakawa Chemical Co., Ltd .: Tamanol 361) 25 parts Non-volatile oil (Nippon Oil Co., Ltd .: C machine oil) 70 parts Polyethylene wax 5 parts (Hoechst Chemical Co., Ltd.) : PE520) Melting point 120 ° C.) A varnish having the above composition was prepared in the same manner as in Example 1.

An ink was prepared in the same manner as in Example 1 except that the above varnish was used (wax content: 1.
0%). Next, when the ink was used to print with Preport VT-3500 in the same manner as in Example 1, good results were obtained as in Example 1.

Example 6 (Production of varnish) Rosin-modified phenol resin (Arakawa Chemical Co., Ltd .: Tamanol 361) 25 parts Non-volatile oil (Nippon Oil Co., Ltd .: C machine oil) 70 parts Paraffin wax 5 parts (Nippon Seiwa Co., Ltd.) (Production: SP-0110, melting point 44 ° C.) A varnish having the above composition was prepared in the same manner as in Example 1.

An ink was prepared in the same manner as in Example 1 except that the above varnish was used (wax content 1.
0%). Next, a printing test was carried out in the same manner as in Example 1. As a result, a good printed matter could be obtained without curling up the printing paper. However, the back slipping was of a satisfactory quality, but was slightly inferior to that of Example 1.

Example 7 (Preparation of varnish) Rosin-modified phenol resin (Arakawa Chemical Co., Ltd .: Tamanol 361) 25 parts Non-volatile oil (Nippon Oil Co., Ltd .: C machine oil) 70 parts Polyethylene wax 5 parts (Allied Co .: # 316, melting point 140 ° C.) A varnish having the above composition was prepared in the same manner as in Example 1.

An ink was prepared in the same manner as in Example 1 except that the above varnish was used (wax content: 1.
0%). Next, a printing test was carried out in the same manner as in Example 1. As a result, a good printed image was obtained without curling up of the printing paper, and the backside was also good as in Example 1.
The fixability of the image is slightly lowered.

Example 8 (Preparation of varnish) Rosin-modified phenol resin (Arakawa Chemical Co., Ltd .: Tamanol 361) 5 parts Nonvolatile oil (Nippon Oil Co., Ltd .: C machine oil) 67 parts Paraffin wax (Nippon Seiwa Co., Ltd .: 150 parts, melting point 69 ° C.) 28 parts A varnish having the above composition was prepared in the same manner as in Example 1.

An ink was prepared in the same manner as in Example 1 except that the above varnish was used (wax content 1.
0%). Next, a printing test was carried out in the same manner as in Example 1. As a result, a good printed image was obtained without curling up of the printing paper, and the backside was also good as in Example 1.
The fixability of the image is slightly lowered.

Comparative Example (Preparation of Varnish) Rosin-modified phenol resin (Arakawa Chemical Co., Ltd .: Tamanol 361) 25 parts Non-volatile oil (Nippon Oil Co., Ltd .: C machine oil) 75 parts The same composition as in Example 1 I made a varnish.

An ink was prepared in the same manner as in Example 1 except that the above varnish was used (wax content: 0).
%). Next, when the ink was used to print with Preport VT-3500 in the same manner as in Example 1, a large amount of curling up of the printing paper occurred. In addition, the back slip was worse than that of Example 1.

Since the water-in-oil type stencil printing emulsion ink of claim 1 contains a wax component in the oil phase, the ink allows good separation of the printing paper from the ink drum during printing. Therefore, the roll-up of the paper is improved, and the ink after printing is less likely to be transferred to the back of the next printing paper, so that back slippage is prevented.

In the water-in-oil type stencil printing emulsion ink of claim 2, since the content of the wax component is 0.5 to 5% by weight with respect to the total amount of the ink, deterioration of the fixing property of the image is completely prevented. The effect of being able to do is added.

The water-in-oil type stencil printing emulsion ink of claim 3 has a melting point of 50 to 120 ° C. as a wax component.
Since the above-mentioned one is used, there is an effect that it is possible to more surely prevent backsiding and lowering of fixing property.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumiaki Arai Inventor Fumaki Nakamago 1-3-6, Ota-ku, Tokyo Within Ricoh Company (72) Inventor Naoto Shimoda 1-3-6 Nakamagome, Ota-ku, Tokyo Shares Within Ricoh Company (72) Kenichi Yamada 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company, Ltd.

Claims (3)

[Claims] 1. An oil phase of about 10-60% by weight and an aqueous phase of about 90-.
In a water-in-oil type stencil printing ink containing 40% by weight, a wax component is further contained in the oil phase composed of at least a nonvolatile oil or a hardly volatile oil, a colorant, an emulsifier and a resin. Characteristic water-in-oil type emulsion ink for stencil printing. 2. The water-in-oil emulsion ink for stencil printing according to claim 1, wherein the wax component is contained in an amount of 0.5 to 5% by weight based on the total amount of the ink. 3. The wax component has a melting point of 50 ° C. to 120 ° C.
The water-in-oil type emulsion ink for stencil printing according to claim 1 or 2, which is in the range of ° C.