JPH11106691A - Ink for ink occlusion material type stamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject ink hardly being partial even in long-term preservation, suppressing the occurrence of lack and blur on a printed mark, providing a clear printed image, by including a colorant, a specific oily solvent and a hydroxystearic acid. SOLUTION: This ink contains (A) a colorant such as an oil-soluble dye, an inorganic pigment, an organic pigment, etc., (B) one or a mixture of two or more of a vegetable oil, a synthetic oil, a petroleum-based solvent, a polyalkylene glycol-based solvent as an oily solvent and (C) 12-hydroxystearic acid as essential components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stamp ink having a built-in ink.
An ink-absorbing body in which ink is impregnated in an elastic porous body having open cells such as polyurethane or a fiber converging body such as polyester or acrylic is built in, and the volume of the ink-absorbing body is reduced by a pressing operation to eject ink, and paper The present invention relates to an ink suitably used for a stamp to be printed on a printing surface, such as a printing surface.

[0002]

2. Description of the Related Art Conventional inks for stamps include aqueous inks comprising dyes, water-soluble resins and water-soluble organic solvents, and oil-based inks comprising dyes, oil-soluble resins and oil-based solvents. Many are designed so that fluidity is Newtonian fluid. This is to make the ink impregnated in the occlusion body easy to move during continuous printing, thereby improving the ejection of the ink.

[0003] A water-in-oil emulsion ink composed of an oil phase and an aqueous phase is also known. When an ink is printed on a printing surface such as paper, the oil phase component is converted to the printing surface. Penetrate into the water, and at the same time evaporate the aqueous component,
This is to improve the drying property of the print mark.

[0004]

However, in the above-mentioned conventional inks which are designed to be Newtonian fluid, the ink is filled in an occlusion body and stored for a long period of time by, for example, turning the stamp surface sideways. If this is done, the ink moves within the occlusion body, causing a bias. As a result, when printing is performed using the ink that has been stored for a long period of time, there is a problem in that print marks are blurred or missing. Although the ink itself can be made to have a high viscosity in order to suppress this bias, there is a problem that the ink is insufficiently ejected and the print marks are blurred.

In the latter water-in-oil emulsion ink, the water phase component (water), which is a dispersoid in the emulsion ink, evaporates when the emulsion ink is stored for a long period of time. As a result, bleeding of a print mark is generated, and the dispersion system of the emulsion ink itself is broken, thereby separating into an oil phase and an aqueous phase, thereby causing a problem of uneven printing. Therefore, an attempt has been made to add a nonionic surfactant such as sorbitan sesquimonooleate or sorbitan monooleate as an emulsifier to obtain a stable emulsion (dispersed system), but the effect is still insufficient.

[0006]

That is, the present invention relates to a colorant, a mixture of at least one of a vegetable oil, a synthetic oil, a petroleum solvent, and a polyalkylene glycol solvent as an oily solvent; The gist of the present invention is an ink for an ink-occluding body type stamp comprising at least stearic acid.

Hereinafter, the present invention will be described in detail. As the colorant, a conventionally known oil-soluble dye or pigment can be used. The oil-soluble dye can be used as long as it is dissolved in the solvent used. I. Solvent Yellow 14, 16, 29, 33, 56, 9
3, C.I. I. Solvent Red 3, 4, 18, 18
3, 24, 27, 49, C.I. I. Solvent Brown 5, C.I. I. Solvent Green 3, C.I. I. Solvent Blue 5, 7, 25, 35, 70, 9
0, C.I. I. Solvent Violet 8, C.I. I. Solvent Black 3, 7 and the like. These dyes can be used alone or as a mixture, and the amount used is preferably 1 to 30% by weight based on the total amount of the ink.

As the pigment, inorganic pigments such as carbon black, red iron oxide, ocher, ultramarine, navy blue, titanium dioxide and the like, and organic pigments such as insoluble azo, soluble azo, phthalocyanine and quinacridone can be used. These pigments can be used alone or as a mixture. The amount of the pigment used is preferably 1 to 50% by weight based on the total amount of the ink.

The oily solvent is one that stably dissolves an oil-soluble dye or an oil-soluble resin or is used as a dispersion medium for a pigment. However, when stencil printing in which a heat-sensitive element is used to make a heat-sensitive film is used, heat-sensitive printing is used. It must be difficult to dissolve the adhesive between the film support and the heat-sensitive film. If the adhesive dissolves, the heat-sensitive film support and the heat-sensitive film peel off over time, and normal plate making and printing cannot be performed.

Further, a solvent having a low boiling point and high volatility volatilizes from the stamp surface when the stamp surface is exposed to air for a long time,
Because the dye or resin may precipitate and make printing impossible,
As the solvent, those having low volatility are preferable, and because they have a very good affinity for 12-hydroxystearic acid, which is an essential component of the present invention, higher fatty acids such as oleic acid, linoleic acid and linolenic acid, ethylene oxide and propylene oxide And synthetic oils such as polyethers, spindle oils, machine oils, liquid paraffins, petroleum solvents such as motor oils, and polyalkylene glycol solvents such as polyethylene glycol and polypropylene glycol. These may be used alone or in combination of two or more, and the amount used is preferably 30% by weight to 80% by weight based on the total amount of the ink.

The above-mentioned 12-hydroxystearic acid is added for imparting plasticity or thixotropic property to the ink, and for suppressing dropping or blurring of a print mark due to unevenness of the ink due to long-term storage or blurring of the print mark. It is preferable that the ink has an affinity for each component of the ink such as the colorant, the oily solvent, the oil-soluble resin, and the like. Examples thereof include Emalox GEL-03 (manufactured by Yoshimura Oil Chemical Co., Ltd.) and hydroxy. Commercial products such as stearin (manufactured by Kawaken Fine Chemical Co., Ltd.) are exemplified. These commercial products are hydrogenated higher fatty acids (castor fatty acids), the main component of which is 12-hydroxystearic acid, which contains 80-95% of the total commercial products.

The amount of 12-hydroxystearic acid used in the total amount of the ink is 0.05 to 3.0% by weight.
Is preferred. When the content is less than 0.05% by weight, plasticity or thixotropy is hardly imparted to the ink, and there is a possibility that unevenness or bleeding of the ink cannot be suppressed. On the other hand, if the content is more than 3.0% by weight, it becomes difficult to discharge the ink, and there is a possibility that print marks are blurred. Therefore, the amount of the commercially available product based on the total amount of the ink is preferably 0.1 to 3.0% by weight. Particularly, a combination with a petroleum-based solvent is preferable due to heat stability.

In addition to the above essential components, a pigment dispersant, a viscosity modifier, an abrasion resistance improver, an antioxidant,
UV absorbers, set-off inhibitors, preservatives and the like can be used.
In particular, it is preferable that the viscosity adjuster is one that is stably dissolved in a solvent, and as an example, a ketone resin, a rosin-modified maleic resin, a rosin-modified phenol resin, a gum rosin,
Alkyd resin, phenol resin, shellac and the like can be mentioned. These can be used alone or in combination of two or more, and the amount used is 20 to 70% by weight based on the total amount of the ink.
Is preferred.

The ink of the present invention may be any of various known stirring devices,
It can be easily obtained by using a disperser, a centrifuge, and a filter.

As the ink occluding body accommodated in the stamp body and occluding the ink of the present invention, an elastic porous body or a fiber converging body can be used. For example, polyurethane,
Nylon, ethylene-vinyl acetate copolymer, butadiene resin,
An elastic porous material obtained by processing a porous material such as polyamide, polyethylene, polyethylene terephthalate, polyvinyl alcohol, vinylidene chloride, polyvinyl butyral, polyvinyl formal, and polypropylene can be suitably used. Further, the average pore diameter of these porous bodies is 0.1 to
1.0mm, 30-10 cells per cubic inch
0, a porous body having a porosity of 70 to 98%
Double compression is more preferred. In addition, examples of the fiber bundle (including felt, nonwoven fabric, etc.) include acrylic, acetate, nylon, polyethylene terephthalate, cellulose (pulp), viscose rayon, vinylidene, polyurethane, polyurethane, polypropylene, and various animal fibers. Can be used alone or in combination of two or more, and those having a porosity of 60 to 98% can be suitably used.

[0016]

By using vegetable oil, synthetic oil, petroleum solvent, polyalkylene glycol solvent as the oily solvent and 12-hydroxystearic acid as a plasticity or thixotropic agent in the present invention in combination, the imprint of the print mark is deviated. Although it is not clear in detail about the suppression of bleeding, blurring, and the like, it is presumed as follows. In the ink of the present invention,
12-hydroxystearic acid, which is a plasticity or thixotropy-imparting agent, has a hydroxyl group in its molecule, and therefore has a very good affinity for the solvent and is considered to form a three-dimensional structure. Plasticity or thixotropy is provided to uniformly construct the structure. As a result, it is considered that the ink in the ink occluding body hardly moves in a stationary state, and it is possible to suppress the bias of the print mark even after long-term storage. In addition, since the affinity between the plasticity or thixotropy imparting agent and the oily solvent is very good, the solvent can be prevented from evaporating even when stored for a long period of time, and the solvent in the ink as seen in an emulsion ink can be suppressed. It is considered that print marks do not bleed due to the reduction in viscosity due to (moisture) evaporation, and the solvent is not separated from the plastic or thixotropy imparting agent.

[0017]

The present invention will be described in more detail with reference to the following examples. In the examples and comparative examples, a single “part” indicates “part by weight”. In Example 4, the viscosity of the ink was E
Examples 1 to 3 and Comparative Examples 1 to 3 were manufactured by Tokyo Keiki EL using an LD viscometer (ST rotor, rotation speed: 0.5 rpm).
D-type viscometer (3 ° × R9.7 cone rotor, rotation number 0.
5 rpm).

Example 1 <Preparation of Pigment Dispersion Base> JR-600E (titanium oxide, manufactured by Teica Co., Ltd.) 59.78 parts BOP28-70S (alkyd resin, manufactured by Harima Chemicals, Inc.) 21.35 parts Machine oil G -9 (spindle oil, manufactured by Idemitsu Kosan Co., Ltd.) 18.87 parts The above components were mixed by a ball mill for 1 hour to prepare a pigment dispersion base. <Ink conversion> 51.09 parts of pigment dispersion base Synthetic resin TC (ketone resin, manufactured by huls) 37.13 parts Machine oil G-9 8.78 parts Emalox GEL-03 (hydrogenated higher fatty acid, Yoshimura oil) 3.00 parts First, the above-mentioned components other than Emalox GEL-03 are mixed and stirred at 90 ° C. for 5 hours. Then, the temperature is raised to 60 ° C., and Emalox GEL-03 is added and stirred for 1 hour. do it,
A stencil printing ink having a viscosity of 27483 cp white was obtained.

Example 2 Unilube 50MB-168 (POEPOP butyl ether, manufactured by NOF CORPORATION) 23.53 parts Oleic acid D-100 (manufactured by Shin Nippon Rika Co., Ltd.) 23.20 parts Oil pink 312 (oil-soluble dye) 6.98 parts Oil Blue 613 (oil-soluble dye, manufactured by Orient Chemical Industries) 0.26 parts Hariphenol P-1 (rosin-modified phenol resin, manufactured by Harima Chemicals, Inc.) 44.53 parts Emalox GEL-03 1.50 parts First, the above-mentioned components other than Emalox GEL-03 are mixed, and the mixture is stirred at 100 ° C for 6 hours. Then, the temperature is raised to 60 ° C and Emalox GEL-03 is added. After stirring for 1 hour, a purple stamp ink for stencil printing having a viscosity of 18165 cp was obtained.

Example 3 PEG # 300 (polyethylene glycol, manufactured by Sanyo Chemical Industry Co., Ltd.) 51.36 parts Neo Super Blue C-555 (oil-soluble dye, manufactured by Chuo Synthetic Chemical Co., Ltd.) 4.51 parts Marquid No . 32 (rosin-modified maleic resin, manufactured by Arakawa Chemical Co., Ltd.) 42.13 parts Emalox GEL-03 2.00 parts First, the above-mentioned components other than Emalox GEL-03 are mixed, stirred at 100 ° C. for 6 hours, and then stirred. The temperature was adjusted to 60 ° C., Emalox GEL-03 was added, and the mixture was stirred for 1 hour to obtain a light blue stencil printing stamp ink having a viscosity of 20,274 cp.

Example 4 <Preparation of Pigment Dispersion Base> JR-600E 59.78 parts BOP28-70S 21.35 parts Machine oil G-9 18.87 parts The above components were mixed by a ball mill for 1 hour to prepare a pigment dispersion base. Produced. <Ink conversion> 51.09 parts of pigment dispersion base Synthetic resin TC 37.13 parts 5.78 parts of machine oil G-9 6.00 parts of Emalox GEL-03 6.00 parts First, the above components other than Emalox GEL-03 were mixed. Stir at 90 ° C. for 5 hours, then bring the temperature to 60 ° C., add Emalox GEL-03, stir for 1 hour,
A stamp ink for stencil printing having a viscosity of 35486 cp white was obtained.

COMPARATIVE EXAMPLE 1 The procedure of Example 1 was repeated except that Emalox GEL-03 was not used.
A p-white stencil printing ink was obtained.

COMPARATIVE EXAMPLE 2 The procedure of Example 3 was repeated except that Emalox GEL-03 was not used.
A p light blue stamp ink for stencil printing was obtained.

Comparative Example 3 MA-100 (carbon black, manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) 6.00 parts Motor oil # 30 (motor oil, manufactured by Nippon Oil Co., Ltd.) 30.00 parts Nikkor SO-15 (non-coated Ionic surfactant, Nikko Chemicals Co., Ltd.) 6.00 parts Ion-exchanged water 53.80 parts Ethylene glycol 4.00 parts Proxel GXL (antiseptic / antifungal agent, ICI Japan Co., Ltd.) 0.20 parts The above-mentioned mixture of carbon black, motor oil # 30 and Nikkor SO-15 was dispersed in a three-roll mill to form an oil phase. Further, a mixed solution (aqueous phase) comprising ion-exchanged water, ethylene glycol and Proxel GXL was added to the oil phase. To obtain a water-in-oil emulsion ink having a viscosity of 25013 cp.

[0025]

The stamp inks for stencil printing obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were subjected to the following tests.

Preparation of stamp: A sheet-like urethane sponge having a thickness of 2 mm and an average pore diameter of 0.5 mm, a number of cells in a cubic inch of about 50, a porosity of 95%, and a continuous compression hole of three times compression was prepared. And an ink-absorbing body type stamp (size of stamp face: 70 mm × 35 mm) using heat-sensitive stencil paper as a stamp face was prepared.

Test 1: Each of the prepared stamps was left in a constant temperature room at 50 ° C. for three times for each of the inks with the stamp sideways for a certain period of time (4 days, 10 days). It was left for 1 hour in a horizontal position. After that, the heat-sensitive stencil paper of the stamp to be used as the stamp is printed by MAX Corporation.
A stamp maker made a plate in the form of a checkerboard consisting of a square with a side of 2 mm so that the total area of the print marks is 50% of the entire stamp face, and writing paper A (JIS P 320
In 1), printing was performed with a 3.0 kg load and 1 second. The print area of the print mark of the stamp after leaving the stand was expressed as a percentage of the area of the ideal print mark when ink was ejected from all the perforated portions of the stamp surface, and was used as a print rate. Table 1 shows the results.

Test 2: A heat-sensitive stencil sheet of each stamp was produced by a stamp maker manufactured by MAX Co., Ltd.
In the form of a checkerboard consisting of m squares, three plates are made for each ink so that the total area of the print marks is 50% of the entire stamp surface, and writing paper (JIS P 3201)
Was printed with a load of 3.0 kg. Thereafter, the stamp was left in a constant temperature room at 50 ° C. for one month with the stamp face down without contacting the contact surface, and then left for 1 hour at room temperature with the stamp face down, and then again written paper A (JIS P320).
1) Printing with a load of 3.0 kg, 1 sec.
The state of each print mark after months is measured by measuring the length of each side of one square in a checkerboard pattern, and the average value of one stamp is calculated. This is calculated as a theoretical value (the length of one side of the square). Sa:
2 mm). The change in the bleeding of the print marks before and after standing was measured by measuring the length of each side of a square in a checkered pattern before and after standing in a constant temperature room at 50 ° C. for one month, and the average value was used as the deformation rate. Calculation (percentage)
did. Table 2 shows the results.

Initial change rate (%) = Average value of length of each side of initial print marks × 100 / theoretical value of side length Change rate after one month (%) = Print marks after one month Average value of the length of each side × 100 / theoretical value of the length of the side Change rate before and after standing (%) = Average value of the length of each side of the print mark after one month × 100 / initial print mark Of the length of each side of

[0030]

[Table 1]

[0031]

[Table 2]

As described above, the ink of the present invention is used for a stamp using an ink occluding material, and is hardly biased even when stored for a long period of time.
At the same time, it is an excellent ink that can suppress bleeding of print marks and obtain a clear printed image.

Claims (1)

[Claims] 1. A colorant and one or more oily solvents of vegetable oils, synthetic oils, petroleum solvents, and polyalkylene glycol solvents.
An ink for an ink-occlusion type stamp comprising at least one kind or a mixture of two or more kinds and 12-hydroxystearic acid.