JPH10219159A - Ink-sorbent-type stamp ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stamp ink which is nonproblematic in unevenness and blotting of ink, plugging of an ink passage due to agglomeration or sedimentation of a pigment after long-term storage and skipped prints in spite of containing a pigment by using at least a flaky pigment, a solvent and a resin. SOLUTION: The flaky pigment is exemplified by a pearl pigment in the form of flaky particles, a flaky metal powder pigment, mica, kaolin clay, pyrophyllite lay or talc. In order to obtain clear printed matter on black drawing paper, it is desirable that the flaky pigment has a particle diameter (volume- means particle diameter) distribution in which the value of integration of particles with diameters in the range of 0.5-40mμm constitutes at least 70% of the value of integration of the entire particles. The solvent is desirably a difficulty volatile one having a boiling point of 250 deg.C or above and is exemplified by a liquid higher fatty acid, castor oil, fluid paraffin or glycerol. The resin used is one which can be stably dissolved in the solvent and is used in such an amount as to adjust the ink viscosity to 5,000-38,000cP.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink for a self-contained stamp, and more particularly, to a stamp body.
Ink-impregnated, built-in ink occluding body which is an elastic porous body having continuous cells such as polyurethane or fiber convergence body such as polyester or acrylic, reduces the volume of the ink occluding body by pressing operation, and ejects ink, The present invention relates to an ink suitably used for a stamp to be printed on a printing surface such as paper. 2. Description of the Related Art A stamp having a built-in ink occluding body impregnated with ink is known as a stamp which can easily print free characters and figures in a short time. Further, there is a type using a heat-sensitive stencil sheet perforated by thermal energy as a stamp surface for forming a print mark. JP-A-8-209050 discloses an ink used for such a stamp.
Japanese Patent Application Publication No. JP-A-2003-115125 discloses a method in which a pigment is used as a colorant, and the viscosity of the ink is specified to prevent the ink from being biased in the ink occluding body and the bleeding of printed marks. [0003] In the case of using a pigment as a colorant for the ink, in addition to the problems solved by the above-mentioned prior art, such as the unevenness of the ink and the bleeding of the ink, the aggregation of the pigment over time, Settling occurs, causing clogging of the ink passage on the stamp surface,
There was a problem that blurring and dropping occurred in the print marks.
As a means for improving the dispersion stability of the pigment in the ink, it is known to set the viscosity of the ink to be high as in the above-described prior art, but it is not preferable to increase the viscosity too much in terms of ink ejection. However, this may be an obstacle to impregnating the ink into the ink occluding body. [0004] The present invention provides a flaky pigment,
The gist of the present invention is an ink for an ink-occlusion body type stamp comprising at least a solvent and a resin. The flaky pigment is a pigment in which the pigment particles have a flaky shape, and examples thereof include pearl pigments, flaky metal powder pigments, mica, carion clay, limestone clay, and talc.
Pearl pigments are also referred to as pearlescent pigments. The surface of natural mica or artificial mica obtained by melting and recrystallizing aluminum oxide, magnesium oxide, etc., is treated with high refractive index metal oxides such as titanium oxide and / or iron oxide. Covered with an object,
It is a pigment that develops brilliant color by interference of light due to regular multiple reflection of incident light, and has a flaky shape with a thin and flat plate surface. Further, there is a colored pearl pigment in which the surface coated with a metal oxide is colored with an organic pigment. Specifically, Iriodin (Ir
iodin) 100 series, Iriodin 200 series, Iriodin 300 series, Iriodin 500 series (all manufactured by Merck Japan KK), and Ultimica (ULTIMICA) series (manufactured by Topy Industries, Ltd.)
Etc. The flaky metal powder pigment is a metal powder obtained by mechanically pulverizing a metal such as aluminum, stainless steel, brass, nickel, copper, zinc, and tin, and has a thin and flat surface. Specifically, Cu-S (C3), C
u-S (E3) Cu-S (3L3), Sn-S-20
0, Pb-S-200, Zn-S-100, Mn-S-
100, Cr-S-100, Si-S-250, BRO
NZE & ALUMINUM POWDER Series (Fukuda Metal Foil & Powder Industry Co., Ltd.), Aluminum Powder Series, Aluminum Paste Series (Daiwa Metal Powder Co., Ltd.), Al Paste Series, High Print TD Series (Toyo Aluminum (Toyo Aluminum) Co., Ltd.). Each of the flaky pigments can be used alone or in combination of two or more, and can be used even if a pearl pigment and a flaky metal powder pigment are mixed. When printing on black paper, in order to obtain a clear print, the integral value in the range of 0.5 to 40 mμ in the particle size distribution of the pigment particle size (volume particle size) is 70% of the integral value of the entire particle size distribution. % Or more, and it is desirable that the integrated value in a range larger than 40 mμ in the particle size distribution be 10% or less of the integrated value of the whole particle size distribution. The pigment particle diameter is 0.5 m
When there are many objects having a size of μ or less, the concealability of the printed matter is low, and the printed matter is unclear. When there are many objects having a size of more than 40 μm, it is necessary to increase the size of the hole formed in the heat-sensitive stencil, and the resolution of the printed matter is lowered. The solvent is used to impart fluidity to the ink and to be used as a dispersing medium for the colorant and as a solubilizing agent for the resin and the dye, and is preferably a solvent which is hardly volatile and has a boiling point exceeding 250 ° C. For example, oleic acid, linoleic acid, linolenic acid, and other higher fatty acids that are liquid at room temperature, castor oil, liquid paraffin, machine oil, polyoxyethylene (POE), polyoxypropylene (POP), alkyl ether, P
Examples thereof include OP alkyl ether, POE alkyl ether, polyethylene glycol, polypropylene glycol, a copolymer of ethylene oxide and propylene oxide, glycerin, and benzyl alcohol. The resin is added to adjust the viscosity of the ink. There is no particular problem as long as it can be stably dissolved in a solvent. One example of a resin that is stably dissolved in the solvent is gum rosin. And rosin-modified maleic resin, rosin-modified phenol resin, phenol resin, ketone resin, alkyd resin, shellac and the like.
These resins can be used alone or as a mixture. If necessary, in addition to the above essential components, a surfactant,
Volatile organic solvents, UV absorbers, preservatives and the like can be used. Further, the ink of the present invention can be easily obtained by using various known stirring devices, dispersers, centrifuges, and filters. Here, the viscosity of the ink of the present invention is 5000
~ 38000 centipoise (Temperature 25 ° C, Tokyo Keiki E
Measured with LD viscometer, 3 ° × R9.7 cone rotor. The rotation speed is preferably in the range of 0.5 rpm. When the ink viscosity is lower than 5,000 centipoise, even if the ink is impregnated into the ink occluding material, the pigment is likely to coagulate and settle over time to easily close the holes on the stamp surface, and the printed matter may be blurred or missing. If the ink viscosity is higher than 38,000 centipoise, the movement of the ink hardly occurs at the time of printing, and the printed matter is liable to cause blurring and dropping. As the ink occluding body for 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, polyamide, polyethylene, polyethylene terephthalate, polyvinyl alcohol, vinylidene chloride, polyvinyl butyral, polyvinyl formal, and polypropylene are processed into a porous material to form an elastic porous body. The body can be suitably used. The porous body has an average pore diameter of 0.1 to 1.0 mm, the number of cells per cubic inch is 30 to 100, and the porosity is 70% to 98%.
% Of the porous material is more preferably compressed from non-compressed to 5-fold. Further, as a fiber bundle, acrylic, acetate, nylon, polyethylene terephthalate, cellulose (pulp), viscose rayon, vinylidene, polyurethane, polypropylene, various animal fibers and a mixture thereof have a water retention of 60% to 98%. A fiber bundle including a nonwoven fabric can be suitably used. When the viscosity of the ink is 5,000 to 38,000 centipoise (25 ° C.), when the ink is impregnated in the ink occluding body, the ink is held in the gap of the ink occluding body, and unless the force such as an external pressure acts thereon. It becomes difficult to flow. Therefore, the coagulation and sedimentation of the pigment in the ink occluded by the ink occlusion body is limited to a small area because the ink does not flow, and the dispersed state is maintained when viewed as a whole of the ink occlusion body.
In particular, pearl pigments and metal powder flake pigments, which are flake pigments, have a large number of gaps between particles even if aggregates are formed due to the flake shape having relatively varied sizes,
Since it has a relatively large surface area, a large amount of resin or surfactant is adsorbed to each particle to cause steric hindrance, and thus it is easily redispersed with a weak force. In the ink-occlusion type stamp, a pressing force is applied to the ink-occlusion body every time printing is performed to deform the ink-occlusion body. Therefore, this force acts on the aggregate of the flake pigment, and the pigment that has aggregated and settled can be redispersed. Hereinafter, the present invention will be described in more detail with reference to examples. In the examples and comparative examples, “parts” simply indicates “parts by weight”. The pigment particle size distribution is LPA-3000 (light scattering particle size distribution analyzer manufactured by Otsuka Electronics Co., Ltd.), and the viscosity is ELD viscometer manufactured by Tokyo Keiki (3 ° × R9.7 cone rotor, rotation speed 0.5 rpm, (Shear rate 1 / sec). Example 1 Unilube 50MB-168 (POEPOP butyl ether, manufactured by NOF Corporation) 23.0 parts Oleic acid D-100 (manufactured by Shin Nippon Rika Co., Ltd.) 23.0 parts Pale Gold No. 500 (pulverized copper-zinc alloy powder, manufactured by Fukuda Metal Foil & Powder Co., Ltd.) 8.0 parts Hariphenol P-1 (rosin-modified phenol resin, manufactured by Harima Chemicals, Inc.) 46.0 parts After mixing except for the powdered pigment and stirring at 100 ° C. for 6 hours, a metal powdered pigment was added and further stirred for 1 hour to obtain a golden stamp ink. The integral value in the range of 2 to 35 mμ in the particle size distribution of the volume particle size of the pigment of this ink was 90% of the whole particle size distribution (average 6 m).
μ). The viscosity is 24000 centipoise (25 ° C)
Met. Example 2 Unilube 50MB-168 22.0 parts Oleic acid 22.0 parts Pale Gold No. 500 8.0 parts C.I. I. Pigment Blue 15-3 (blue pigment) 1.0 part Reodol SP-O10 (sorbitan monooleate, dispersant, manufactured by Kao Corporation) 2.0 parts Hariphenol P-1 45.0 parts Unilube in the above components 50MB-168, C.I. I.
Pigment Blue 15-3, Rheodol SP-
O10 was mixed and dispersed in a three-roll mill (three passes). From the remaining composition, Pale Gold No. 50
After mixing except for 0 and stirring and dissolving at 100 ° C. for 6 hours,
PaleGold N with dispersed pigment after roll mill
o. 500, and the mixture was further stirred for 1 hour to obtain a bluish golden stamp ink. The integral value in the range of 2 to 35 μm in the particle size distribution of the volume particle size of the pigment of this ink was 90% of the entire particle size distribution (average 6 μm). The viscosity is 26
000 centipoise (25 ° C.). Example 3 PEG # 300 (polyethylene glycol, manufactured by Sanyo Chemical Industries, Ltd.) 49.0 parts Iriodin 504 (pearl pigment having natural mica coated with iron oxide, manufactured by Merck Japan Ltd.) 10.0 Part Rhodol SP-O10 1.0 part Marquid No. 32 (rosin-modified maleic resin, manufactured by Arakawa Chemical Co., Ltd.) 40.0 parts The above components were mixed except for the pearl pigment, and the mixture was stirred for 6 hours while heating at 100 ° C., and then the pigment was added and further stirred for 1 hour. Thus, a stamp ink having a red glow was obtained. 4 to 4 in the particle size distribution of the volume particle size of the pigment of the ink.
The integrated value in the range of 0 μm was 90% of the whole particle size distribution (average: 15 μm). The viscosity is 18000 centipoise (2
5 ° C.). Example 4 PEG # 300 46.0 parts ULTIMICA SB-100 (pearl pigment coated with titanium dioxide on artificial mica surface, manufactured by Topy Industries, Ltd.) 10.0 parts Hariphenol P-1 39.0 parts Marquid No. 32 5.0 parts The above components were mixed except for the pearl pigment, and the mixture was stirred for 6 hours while heating at 100 ° C., and then the pigment was added to obtain a silver-colored stamp ink. The integral value in the range of 3 to 35 mμ in the particle size distribution of the volume particle size of the pigment of this ink was 90% of the entire particle size distribution (average 10 mμ). The viscosity was 6000 centipoise (25 ° C.). Example 5 Unilube 50MB-168 28.5 parts Oleic acid D-100 28.5 parts Pale Gold No. 500 8.0 parts Hariphenol P-1 35.0 parts The above components are mixed except for the metal powder pigment, and the mixture is stirred at 100 ° C. for 6 hours. Stamp ink was obtained. The integral value in the range of 2 to 35 mμ in the particle size distribution of the volume particle size of the pigment of this ink was 90% of the whole particle size distribution (average 6 m).
μ). The viscosity was 4000 centipoise (25 ° C.). EXAMPLE 6 39.0 parts of PEG # 300 10.0 parts of Iriodin 504 10.0 parts of Rhodol SP-O10 1.0 part of Marquid No. 32 50.0 parts The above components were mixed except for the pearl pigment, and the mixture was stirred for 6 hours while heating to 100 ° C., and then the pigment was added and further stirred for 1 hour to obtain a stamp ink having a red glow. 4 to 4 in the particle size distribution of the volume particle size of the pigment of the ink.
The integrated value in the range of 0 μm was 90% of the whole particle size distribution (average: 15 μm). The viscosity is 43000 centipoise (2
5 ° C.). Example 7 PEG # 300 46.0 parts Mica 10.0 parts Hariphenol P-1 39.0 parts 32 5.0 parts Mica was removed from the above components, and the mixture was stirred while heating to 100 ° C. for 6 hours. Then, a pigment was added to obtain a silver-white stamp ink. The integral value in the range of 5 to 40 μm in the particle size distribution of the volume particle size of the pigment of this ink was 90% of the whole particle size distribution (average 18 μm). Viscosity is 8000
It was centipoise (25 ° C.). Comparative Example 1 Unilube 50MB-168 22.5 parts Oleic acid D-100 22.5 parts C.I. I. Pigment Blue 15-3 6.0 parts Taipaque R-830 (titanium oxide, white pigment, manufactured by Shiraishi Sangyo Co., Ltd.) 10.0 parts Leodol SP-O10 4.0 parts Hariphenol P-1 35.0 parts Medium, Unilube 50MB-168, C.I. I.
Pigment Blue 15-3, Taipaque R-8
30, Reodol SP-O10 was mixed and dispersed with a three-roll mill (three passes). Mix the remaining ingredients and mix
After stirring and dissolving at 0 ° C. for 6 hours, the dispersed pigment ascended from the roll mill was added, and the mixture was further stirred for 1 hour to obtain a bluish stamp ink. The integral value in the range of 0.5 to 3.6 mμ in the particle size distribution of the volume particle size of the pigment of this ink was 90% of the entire particle size distribution (average 0.7 μm). 140 viscosity
00 centipoise (25 ° C.). Comparative Example 2 Unilube 50MB-168 28.5 parts Oleic acid D-100 28.5 parts C.I. I. Pigment Blue 15-3 6.0 parts Reodol SP-O10 2.0 parts Hariphenol P-1 35.0 parts Unilube 50MB-168, C.I. I.
Pigment Blue 15-3, Rheodol SP-
O10 was mixed and dispersed in a three-roll mill (three passes). The remaining components were mixed and dissolved by stirring at 100 ° C. for 6 hours, and the dispersed pigment ascended from a roll mill was added thereto and further stirred for 1 hour to obtain a bluish stamp ink. All of the particle size distributions of the pigment particles of this ink have a volume particle size of 0.12 to 0.1.
It was in the range of 7 μm (average 0.16 μm). Viscosity is 1
It was 1000 centipoise (25 ° C.). Comparative Example 3 49.0 parts of PEG # 300 C.I. I. Pigment Violet 19 4.0 parts Rheodol SP-O10 1.0 part 32 46.0 parts Of the above components, 20 parts of PEG # 300 and C.I. I. Pig
Ment Violet 19 and Rheodol SP-O1
And mixed with a three-roll mill (three passes). While heating the mixture of the remaining composition to 100 ° C., 6
After stirring for an hour, the dispersed pigment after the roll mill treatment was added, and the mixture was further stirred for 1 hour to obtain a violet stamp ink. All of the particle size distributions of the volume particle size of the pigment in this ink were in the range of 0.14 to 0.8 mμ (average 0.2
8 mμ). The viscosity was 32000 centipoise (25 ° C.). The inks of Examples 1 to 7 and Comparative Examples 1 and 2 were prepared using an average pore diameter of 0.5 mm and a cell number of about 5 cells per cubic inch.
It was filled into a urethane sponge having 0, a porosity of 95%, and a continuous air hole of three times compression. This was combined with a print master manufactured by Riso Kagaku Kogyo Co., Ltd., and installed in a housing to prepare an ink-absorbing body stamp (stamp face size: 70 mm × 35 mm) using heat-sensitive stencil paper as a stamp face. This heat-sensitive stencil master was made by a stamp maker manufactured by MAX Co., Ltd. so that a straight line having a width of 0.3 mm and a length of 5 cm was formed so as to obtain six print marks at intervals of 5 mm, and a printing test was performed. Table 1 shows the results. [Table 1] Test Method: Fuzzy length stamp of print mark immediately after plate making The stamp was left at 50 ° C. for 1 week with the printing surface facing down, and the plate was made to measure the blurred and missing portions of the printed matter and totaled (10 times). The stamping operation was performed, and the first, second, and tenth printed matters were evaluated.) Cut length of printing mark after diameter
The printed matter was allowed to stand for a week, and the blurred and missing portions of the printed matter were measured and totaled (the stamping operation was performed ten times, and the first, second, and tenth printed matters were evaluated). When printing was performed, the farthest distance at which a print mark was visible was measured. The average value of 10 men and women in their 20s to 40s is shown. As described above, the ink of the present invention is less likely to cause blurring or bleeding of print marks even when stored with the ink embedded therein, even if it occurs several times, as an ink for an ink-absorbing stamp. This promotes the re-dispersion of the aggregation of the pigment by the imprinting operation, and can eliminate the blurring and missing of the print mark.

Claims (1)

Claims: 1. An ink for an ink-occluding body type stamp, comprising at least a flaky pigment, a solvent, and a resin.