JPS6020975A - Ink for infrared absorbing marker - Google Patents

Abstract

PURPOSE:To provide the titled ink which inhibits reflection of light in the infrared wavelength region and has excellent resistance to staining and marring, quick-dryness, readability, etc., consisting of carbon black or Nigrosine dye, an org. solvent, a resin and a specified matting agent. CONSTITUTION:10-200wt% (based on the quantity of resin) matting agent selected from among inorg. extender (e.g. CaCO3) and fine org. powder (e.g.PE) having a particle size of 20mu or below and insoluble in org. solvent is blended with an infrared absorbing ink obtd. by dipersing or dissolving 0.5-25wt% carbonblack or Nigrosine dye and an org. solvent-soluble resin (e.g. terpene resin) in an org. solvent (e.g. ethylcyclohexane) having a b.p. of 160 deg.C or below, in such a quantity that the combined quantity of the resin and the matting agent amounts to 10-50wt%. If necessary, a high-molecular dispersant is added thereto to adjust its viscosity to 10-30cp at 20 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink for infrared fa-absorbing markers. Specifically, it suppresses reflectance to infrared wavelengths, provides highly efficient infrared absorption, significantly improves readability, and satisfies stain resistance, scratch resistance, quick drying properties, and the like. The present invention relates to an infrared absorbing marker ink that forms sharp handwriting on a mark sheet and is effective for pattern recognition of electronic knitting machines and various other application fields of optical mark reading devices.

Conventionally, black pencils have been mainly used as a writing material for reading optical marks, but the excessive markings caused by overlapping the marks tend to give gloss to the handwriting, reflect some infrared light, and reduce readability. Furthermore, the writing properties on the film surface are not satisfied. In addition, Tokushu Sho 50-1825. Although it is disclosed in Japanese Patent Application Laid-Open No. 7200, etc., it is not possible to form an image with sufficient light absorption for infrared wavelengths on the mark sheet, especially when the mark sheet material is a non-permeable film. , in the case of embossed paper 9-sha paper, etc.
A decrease in reading efficiency due to reflection of infrared light could not be avoided. It also shows sufficient performance in terms of handwriting stain resistance, scratch resistance, etc., and details will be explained below.

The present invention is characterized by the use of carbon black or nigrosine dyes,
In infrared absorbing ink using organic solvent and resin,
A matting agent selected from organic fine powders or inorganic extenders insoluble in organic solvents is added in an amount of 10 to 200% (preferably 18 to 50% by weight) based on the resin, and the sum of the resin and matting agent is 10 to 50% by weight in the ink. % (preferably 20 to 40 weight ff1%) of the ink for infrared absorbing markers, and is characterized in that it is blended within the range of 20% to 40% (preferably 20% to 40% by weight), and a polymeric dispersant is added if necessary.

In the above, the matting agent is used in combination with a resin to effectively form a film that minimizes the gloss of handwriting on track marking sheet materials, especially non-permeable films, embossed paper, synthetic paper, etc. The matting agent has the role of suppressing light reflection and absorbing it with high efficiency, improving readability and increasing the adhesion of handwriting.The matting agent takes into consideration ink dispersibility, ink flow from the pen body, handwriting performance, etc. A particle size of 20 tL or less is effective, and specifically, benzoguanamine-formalin condensate, fine organic powder insoluble in organic solvents such as finely powdered polyethylene, magnesium carbonate, calcium carbonate, barium sulfate, silica, talc, Examples include inorganic conditioning agents such as kaolin clay, white carbon, titanium oxide, and calcium oxide.

The matting agent is blended in an amount of 10 to 200% by weight based on the resin, and the sum of the resin and the matting agent is in the range of 10 to 50% by weight in the ink.

If the ratio of the matting agent to the resin is less than 10% by weight, effective matting properties will not be expressed and the absorption of infrared wavelengths will not be satisfied.On the other hand, if the matting agent exceeds 200% by weight, the amount of the matting agent in the film will be excessive. This weakens stain resistance and abrasion resistance. In addition, the sum of ura resin and matte agent in the ink is 10% by weight.
If it is less than 50% by weight, a film that satisfies the absorption of infrared wavelengths will not be obtained, and if it exceeds 50% by weight, the ink will become thicker and the ink flow from the writing body will be reduced. In order to satisfy the dispersion stability of the ink, the flow of the ink from the writing, give sharp handwriting, and obtain the desired effect, the viscosity of the ink is 10.
It is important to maintain the temperature within the range of ~80 centivoices (20'C), and the blending amount within the above range satisfies this.

Here, the resin is soluble in an organic solvent. Hydrocarbon resins, terpene resins, styrene resins, acrylic resins, ketone resins, phenolic resins, rosins, cellulose resins,
Examples include vinyl acetate resin, butyral resin, and maleic acid resin. The resin imparts an appropriate amount of fineness to the ink, improves dispersion stability, provides sharp handwriting, and also contributes to fixing the matting agent and coloring agent to form an effective flat film.

Examples of the solvent include aromatic, aliphatic, or alicyclic hydrocarbons, ketones, esters, alcohols, glycol ethers, etc., and dissolve the above-mentioned resins. boiling point 160
Solvents that dry quickly below 20'C are selected and primarily applied.

The carbon blank and nigrosine dye as infrared absorbing colorants are used in an amount of 05 to 25% by weight, preferably 2 to 15% by weight.

Various polymeric dispersants are blended into the above-mentioned ink as needed to further improve the dispersion effect and to create matting agents, matting agents, etc.
It suppresses carbon black sedimentation, ink thickening, and gelation, and prevents the ink components from becoming uneven in the pen body over time.

The ink of the present invention can be effectively used by filling a marker with a "liquid type structure" in which the ink is drawn out from the ink tank to the pen body by operating a valve body. More specifically, it is convenient to purchase an ink tank filled with stirring balls, etc. that stir and redistribute the ink, and the pen body is made up of a fixed body of fiber bundles and a plastic with a through-hole in the internal axial direction. Depending on the purpose, a plastic porous body with continuous pores, etc. may be used.

Next, Examples and performance comparisons of the inks of the present invention are described in Attached Tables 1 and 2. In addition, all the formulations in the examples are heavy foot parts.

Ink Preparation Method Inks of Examples 1 to 4 After adding the resin to the organic solvent and dissolving it with a high-speed disperser, adding the dye and dye dissolving aid if necessary and stirring for 1 hour, adding a matting agent, The mixture was further stirred for 1 hour to prepare an ink.

The ink pigments of Examples 5 to 8, resins, and matting agents were pre-kneaded in a two-kneader, and then cross-mixed with eight rolls to obtain easily dispersible processed pigments.

Next, the processed pigment was added to an organic solvent in which a resin was dissolved together with a dispersant as necessary, and dispersed for 2 hours using a high-speed disperser to prepare an ink.

Explanation of the performance comparison table ■Reading performance: 700 to 95. When projected onto a mark on polypropylene synthetic paper using a light emitting diode with wavelength characteristics of a string, 400
The light is received by a 7 auto diode which has a sensitivity characteristic of wavelengths of nm or more and is read by a voltage (Port).If it is 0.8V or less, it is determined that readability is acceptable.

Readability over time: After soaking the ink into the pen body of the marker, leave it at 50°C for one month in a Royal oven (with the pen body facing upwards), then mark it on PP (polypropylene) synthetic paper and read it.

■Scratch resistance Erasability with eraser under 100g load 08 No change after 10 times of rubbing, △: Slight peeling after 5 to 10 times, ×: Peeling after ~5 times ■Mark performance (on PP synthetic paper) Dot writability: 2 Apply the squares of the millimeter grid so that they do not protrude.

○: It is possible to make 1000 dots in a row. Δ: It becomes impossible to make dots between 100 and 1000 dots due to wear of the lead or the tip of the pen body.

X: l 00 dots or less on the side where it is impossible to dots mWriting propertiesWriting conditions Handwriting test with a load of 100g, an angle of 60°, and a speed of 10m/min 0: Writing width after zoom is 2fX or less △: Writing width after 20m 2x or more ×: Writing width after 2m is 2% or more ■Wettability (riding condition) on the hair-permeable mark sheet O:
Shows good wettability with no repellency or discoloration.

△: There is a slight skip and the handwriting is not well placed.

As exemplified in the performance comparison table above, the ink of the present invention exhibits satisfactory performance in terms of durability compared to conventional solid writing materials. In addition, compared to conventional infrared absorbing inks that do not contain matting agents, readability is significantly improved, and combined with practicality such as writing performance and handwriting performance, it can be used for printing fine characters, fine lines, dots, etc. It is possible to mark a variety of images and read them with high efficiency.

Claims (1)

[Claims] Carbon black or nigrosine dye. In infrared absorbing ink using organic solvent and resin,
10 to 200% by weight of a matting agent selected from organic fine powders or inorganic extenders insoluble in organic solvents based on the resin.
An ink for an infrared absorbing marker, in which the sum of the resin and the matting agent is blended in the ink in a range of 10 to 50% by weight, and a polymeric dispersant is added as necessary.