JPH0313995B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to desensitizing inks for recording materials. More specifically, the purpose is to prevent color development or erase a developed color image of a recording material such as a carbonless pressure-sensitive recording material or a heat-sensitive recording material, which is composed of a combination of a colorless or light-colored dye precursor and a color developer that develops the color. This invention relates to a new desensitizing ink. Currently, the most famous such recording materials are carbonless pressure-sensitive recording materials, heat-sensitive recording materials, etc. Among these, for example,
149123, No. 54-53538, etc., image recording materials consisting of a coloring system that combines a heat sublimable dye precursor and a solid acid color developer, or images using a similar coloring mechanism. There are also thermal transfer image recording materials, and the present invention is useful for all of them. Since the so-called desensitization technology for preventing or erasing color development in these recording materials has seen the most development in carbonless pressure-sensitive recording materials, the present invention will mainly describe this in detail, but is not limited thereto. That's right. Carbonless pressure-sensitive recording materials usually include crystal violet lactone, benzoylleucomethylene blue, 3-diethylamino-6-methyl-
Electron-donating leuco dyes (dye precursors), such as 7-anilinofluorane, malachite green lactone, and rhodamine anilinolactam, are dissolved in non-volatile oil and incorporated into fine capsules, which are then printed on paper or plastic. The top paper is coated on a support such as a film, and an electron-accepting substance (developer) such as activated clay such as activated clay, phenol resin, salicylic acid derivative polyvalent metal salt, etc. is coated. It consists of a bottom paper,
When the coated surfaces of both papers are placed facing each other and pressurized, the contents of the capsule and the color developer come into contact and color develops. Furthermore, if an inner sheet coated with a color developer on the front side and a dye precursor on the back side is used, an even larger number of copies can be recorded.
Furthermore, self-contained papers in which a color developer and a dye precursor are coated on the same side of a support in a laminated state or in a single layer are also in practical use. Desensitizing ink is usually applied to a surface where a color developer is present, and it either pre-covers areas that do not need color development to prevent color development, or it is suitable for areas that have already developed color and erases the developed color image. used for a purpose. In order to actually apply desensitized ink to the developing surface, it is necessary to improve the accuracy of repeated operations (improve registration), improve the surface quality of the application surface, improve the accuracy of the amount of adhesion, and increase the number of form designs. Various printing methods (flexo/gravure printing, letterpress printing, offset printing, silk screen printing,
etc.), and therefore, desensitizers, other auxiliary materials, additives, etc. are blended to create inks that are compatible with these printing methods and put into practical use in the form of compositions. (A composition formulated for printing in this way is called a desensitizing ink.) For this reason, the properties required of a desensitizing agent are as follows:
In addition to the ability to prevent and erase color development, that is, the ability to desensitize, it is also possible to prepare desensitized inks that have printability suitable for various printing methods. (Furthermore, after being applied to the recording material, it may cause yellowing coloration, the desensitizer may diffuse and migrate and desensitize the desired coloring area, or it may destroy the adjacent microcapsules containing the dye precursor. (Of course, you should not do that.) There have been many proposals regarding desensitizers, but
Those selected based on a long history of use are thought to be mainly alkylene oxides (e.g., ethylene oxide, propylene oxide, butylene oxide, etc., or styrene oxide, adducts) to aliphatic monoamines, diamines, triamines, etc. (Tokuko Sho 46-29546, Tokko Sho
No. 49-23850, Special Publication No. 14571, Special Publication No. 14571, No. 49-
No. 19647, Special Publication No. 1977-23008, Special Publication No. 1977-29365
No., Special Publication No. 51-39571, Japanese Patent Publication No. 56-67291,
etc). As a result of detailed studies by the present inventors, we found that alkylene oxide adducts of monoamines have insufficient desensitizing ability, and that alkylene oxide adducts of polyamines such as diamines, triamines, tetramines, pentamines, etc. As the number of amines increases, desensitizing ability generally improves, but conversely, as the polarity increases, the water regulating property increases (in other words, the lipophilicity decreases), which makes it particularly difficult to prepare inks for offset printing. Moreover, when applied to a color developer layer using phenol resin as a color developer, a serious drawback was found in that it yellowed significantly over time and when exposed to light. In other words, increasing desensitization ability is contradictory to increasing lipophilicity to improve printability in offset printing, letterpress printing, etc., as well as preventing yellowing and capsule destruction. For example, with an aliphatic amine/alkylene oxide adduct, it is difficult to satisfy both of these contradictory requirements, and it has not been possible to produce a fully satisfactory desensitizing ink. Therefore, as a result of intensive research in order to meet these conflicting demands, the present inventors finally found the general formula used in the present invention: R-O-(CH ₂ ) ₃ -NH ₂ (wherein R is C ₈ H ₁₇ -, C ₁₀ H ₂₁ -, and other alkyl groups having 8 or more carbon atoms). Excellent desensitizing ink can be obtained by blending an alkylene oxide (e.g., ethylene oxide, propylene oxide, butylene oxide (three types of isomers), etc.) or styrene oxide adduct to 3-alkoxypropylamine with an ink vehicle and a pigment. The present invention was achieved based on the discovery that the following is true. The types of alkylene oxides to be added to 3-alkoxypropylamine during the synthesis of the desensitizer may be either a single type, like a homopolymer, or multiple types of alkylene oxides may be added like a copolymer. It's okay. (Again, in this case, the bonding order may be irregular, as in a random copolymer, or, as in a block copolymer, one type of alkylene oxide is added first, then the other type, and then (Different types may be added.) The total number of moles of alkylene oxide and styrene oxide added may be any number of moles, but it is generally preferred to have 8 moles or more. For example, to 1 mole of 3-(2-ethylhexyloxy)propylamine, first ethylene oxide 4
mol and then propylene oxide 10
An example of the desensitizer used in the present invention obtained by adding 10 moles of butylene oxide to 10 moles of butylene oxide is shown by the following chemical structural formula. (However, a+a'=4, b+b'=10, c+c'=10) The obtained desensitizer is a viscous liquid that is slightly yellowish brown but almost colorless and transparent. The oxide compounds to be added include ethylene oxide, propylene oxide, butylene oxide (there are three types of isomers such as 1,2-butylene oxide, 2,3-butylene oxide, and isobutylene oxide), styrene oxide, etc. As the amount increases, the lipophilicity increases and the desensitization ability decreases somewhat. In addition, the viscosity tends to increase as the number of added moles increases, and the higher the molecular weight, the less likely diffusion or migration will occur when applied to a paper surface. Desensitization ability is also influenced by the number of moles added. Therefore, the type of alkylene oxide or styrene oxide and the number of moles added may be determined experimentally depending on the purpose of use, and the desensitizer used in the present invention is characterized by the ability to freely design the molecule. In order to actually produce a desensitizing ink using this desensitizer, (A) a pigment, (B) a vehicle, and (C) the desensitizer are basically required. (In addition, it is normal to add solvents, deterioration inhibitors, fluorescent brighteners, waxes such as paraffin wax, other additives, or other types of desensitizers, etc. to improve practical quality.) (A) Pigments mainly adjust the viscosity of desensitized inks,
Opaqueness, mattness, ease of addition to desensitized printed areas,
For example, inorganic pigments such as titanium dioxide, zinc oxide, calcium carbonate, magnesium carbonate, silicon dioxide, urea resin, etc.
Organic pigments (plastic pigments) such as melamine resin, styrene resin, etc. are used. (B) Vehicle is a liquid component that disperses pigments, gives fluidity to ink, and fixes pigments on the printing surface.It usually consists of solvents, resins, etc., vegetable oil,
Mineral oil, cooked linseed oil, alkyd resin, maleic acid resin, rosin-modified phenolic resin, vinyl resin, etc. are used. Further, by selecting and using a general UV-curable vehicle, a UV-curable desensitized ink can be produced. UV-curable vehicles include compounds with unsaturated bonds, usually ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyhydric alcohols such as glycerin and trimethylolpropane, and acrylic acid or methacrylic acid. esters, terminal epoxy acrylates of various glycidyl ethers,
methacrylates, these monomers, dimers, trimers, oligomers (propolymers),
is mainly used, and unsaturated alkyd resins, non-drying oils, oil-modified alkyd resins, arylsulminamide/formalin resins, epoxy resins, urea/formalin resins, diaryl phthalate resins, etc. are added to provide film-forming ability. Sometimes. As additives, photoinitiators, chain transfer agents, stabilizers, fluidity improvers, waxes, etc. can be added. In this way, by applying an ultraviolet curable ink vehicle, it is possible to make an ultraviolet curable desensitized ink, which can be used to accelerate ink drying, speed up printing, prevent ink not drying, etc., especially in letterpress and offset printing. It becomes possible to bear fruit. Of course, the desensitizers of the present invention can be used in any type of printing ink formulation, such as flexo-gravure printing, letterpress printing, offset printing, silk screen printing, etc. However, the greatest effect is that a desensitizing ink that is still fully satisfactory, which is currently the most widely used printing method, has been developed and that a desensitizing ink that is most suitable for the offset method can be provided. This is true not only for ordinary penetrant-drying inks but also for ultraviolet curing inks. Here, the features of the desensitizer used in the present invention can be summarized as follows: (1) It has better desensitizing ability than alkyleoxide or styrene oxide addition compounds of aliphatic monoamines. (2) It is more lipophilic than alkylene oxide or styrene oxide adducts of aliphatic polyamines, and therefore particularly excellent offset desensitizing inks can be produced. (3) than alkylene oxide or styrene oxide adducts of aliphatic polyamines,
It is excellent in that there is little yellowing when applied to the developing surface of a recording material. In the embodiments of the present invention, even if the desensitizer is used in combination with one or more different types of desensitizers other than those of the present invention, they are all included in the present invention, as they are of course effective. Next, the present invention will be explained in more detail with reference to Examples. All "parts" represent parts by weight. Example 1 (A) 25 parts of titanium dioxide powder as a pigment, (B) a rosin-modified phenol resin (Tokushima essential oil) as a vehicle.
Add 4 mol of ethylene oxide, 10 mol of propylene oxide, and 10 mol of 1,2-butylene oxide to 20 parts of Tespol SPR160 (manufactured by KK) and 1 mol of 3-(2-ethylhexyloxy)propylamine as a desensitizer (C) in this order. A desensitized ink consisting of 50 parts of the ink was prepared. First, (B) was dissolved in (C), and then (A) was added to form an ink using three kneading rolls. Using this desensitizing ink, offset printing was performed on a commercially available carbonless pressure-sensitive recording paper (N-40, using phenol resin as a color developer) using a form printing machine manufactured by Miyakoshi Kikai Seisakusho. (The plates are Fuji Photo Film PS version SGN-, H liquid EU-1
3%, speed 100m/min) Ink volume is approximately 3.5
g/ ^m2 . After printing for 5 minutes, it was confirmed that there was no staining of the printing machine (bracket, water rod) due to desensitizing ink. In this manner, the printed surface of the lower paper, which had been subjected to offset desensitization printing, was opposed to the coated surface of the blue coloring upper paper (N-40, mainly using crystal violet lactone as the dye), and the paper was passed through a supercalender to develop color. No color development was observed in the desensitized printed area, showing good contrast with the blue color development in the undesensitized area (non-image area). Further, no staining due to the desensitizing ink was observed in the non-image areas, indicating that the ink was extremely good as an offset ink. Example 2 (A) 30 parts of titanium dioxide powder as a pigment, (B) a rosin-modified phenolic resin (Arakawa Kogyo Co., Ltd.) as a vehicle.
A desensitizing ink was prepared consisting of 20 parts of Tamanol 353 (manufactured by KK) and (C) 50 parts of the desensitizer shown in Table 1. First, (B) was dissolved in (C), and then (A) was added to form an ink using three kneading rolls. These desensitized inks were printed on a commercially available carbonless pressure-sensitive recording paper N-40 (using phenol resin as a color developer) using a letterpress printing machine (manufactured by Mei Seisakusho). The amount of ink applied was set to 4.5 g/m ² in both cases. Black color-forming paper (N-40, mainly uses 3-diethylamino-6-methyl-7-anilino-fluoran as the dye) is passed through a supercalender with the coated side facing the above-mentioned printed surface to obtain color-preventing ability (i.e., desensitization). performance) was evaluated. In addition, the degree of yellowing caused by NOx gas on the desensitized printed surface was tested (left for 30 minutes in NOx 150 ppm).

【table】

[Table] From Table 1, desensitizing ink No. 1 and No. 1 according to the present invention.
2 is superior to comparative ink No. 4 in desensitization ability,
It can be seen that this ink is superior to comparative ink No. 3 in NOx gas yellowing. Example 3 Ink components: (A) Pigment Titanium dioxide 30 parts (B) Vehicle (ultraviolet curable) Tung oil 12 parts Benzoin methyl ether 4 parts Trimethylolpropane-triacrylate
14 parts (C) Desensitizer 15 moles of ethylene oxide adduct to 3-decyloxypropylamine 40 parts Components other than the pigment were mixed and dissolved, and an ink was prepared using a three-roll mill. Printing was carried out on commercially available paper (N-40, using phenol resin as a color developer) using a letterpress printing machine.
Immediately after printing, the ink was set instantaneously using an ultraviolet irradiation device (manufactured by Toshiba). The desensitization effect was also sufficient. Example 4 Commercially available KS Copybrite bottom paper (N50) (using zinc salt of a satyryl acid derivative as a color developer) was used in place of the bottom paper of Example 3. Both ink setting and desensitization effects were sufficient with the same amount of ink.

Claims (1)

[Claims] 1. Basically (A) a pigment (B) a vehicle and (C) a general formula R-O-(CH ₂ ) ₃ -NH ₂ (wherein R
is an alkyl group having 8 or more carbon atoms)
One or more compounds selected from the group consisting of alkylene oxide adducts, styrene oxide adducts, and alkylene oxide-styrene oxide coadducts to alkoxypropylamine (however, the total number of moles added is 8 moles or more) A desensitizing ink for recording materials. 2. The desensitizing ink for recording materials according to claim 1, wherein the vehicle is a vehicle that is cured by ultraviolet irradiation.