JPS63196673A - Photochromic ink - Google Patents

Abstract

PURPOSE:To provide the title ink which has excellent durability under repeated color changes and is excellent in sensitivity to color changes and shelf stability, by using a spirooxazine compd. and an epoxy resin as essential ingredients in combination. CONSTITUTION:1pt.wt. spirooxazine compd. (A) of formula I or II (wherein R1 and R2 are each H, Cl, CH3, C2H5, C3H7 or methoxy) and 0.01-1,000pts.wt. epoxy resin (B) such as polyethylene glycol diglycidyl ether or bisphenol A type epoxy resin, are used as essential ingredients. The components A and B and a binder component (C) such as a synthetic resin (e.g., vinyl resin, polyolefin resin, etc.), natural resin (e.g., ceramic, copal, etc.), rosin ester, rubber derivative, etc. are dissolved or dispersed in a solvent such as water, an alcohol, an ester, a ketone, etc. If desired, a color tone modifier, a plasticizer, a thickener, an ultraviolet absorber, an antioxidant, etc. are added thereto.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention has the ability to develop or change color when irradiated with light, and when the light irradiation is stopped, the colored material disappears or the colored material returns to its original color tone. This invention relates to a photochromic ink having the following properties.

Many so-called photochromink materials have been known for a long time, which repeat reversibly coloring, fading, or changing color depending on the presence or absence of light irradiation. Typical photochromink materials include G, H,
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These include compounds described in 1971) and spirooxazine compounds (Japanese Patent Publication No. 45-28892). Photochromic inks using these compounds have been proposed.

(Problems to be Solved by the Invention) The characteristics required of the photochromic material constituting the photochromic ink include sensitivity to rapid color development or color change upon irradiation with light, sensitivity to decolorization when light irradiation is stopped,
These include durability that can withstand repeated use, stability that can withstand long-term storage, and ease of making ink.

The spirooxazine compound has the advantage that ordinary photochromic materials have extremely poor durability against repeated use.
It is known to have durability that can withstand practical use. However, when making ink, this spirooxazine compound is not very compatible with other ink components, so
Only a limited number of types of ink are available.

The object of the present invention is to obtain a photochromic ink in which the compatibility of spirooxazine compounds is improved without impairing the above-mentioned performance.

(Means for Solving the Problems) The present invention provides a spirooxazine compound represented by the following general formula [I] or general formula [II] general formula [I] general formula [II] (where Rt, Rt It is a photochromic ink whose essential components are hydrogen atom, chlorine atom, methyl group, ethyl group, propyl group, and methoxy group) and epoxy resin.

While general photochromic materials have poor durability in repeated color development/decolorization and are difficult to put into practical use, the inventors have found that spirooxazine compounds have durability that can withstand practical use, and also have good sensitivity in color development/decolorization and storage stability. Focusing on the advantages, let's use the spirooxazine compound as a photochromic component in the ink to address the aforementioned disadvantage of poor compatibility between spirooxazine compounds and other ink components, such as ink vehicles and medium inks. In this case, the solubility and compatibility of the spirooxazine compound is poor, so it can only be used in a small proportion, resulting in insufficient color density, and when used in a large amount, the spirooxazine compound precipitates, making the ink unstable. We proceeded with the study to improve the system. As a result, it has been found that when an epoxy resin is used in combination with a spirooxazine compound, the compatibility can be improved without impairing the above performance.

The reason why the present invention was able to become an excellent photochromic ink is that the spirooxazine compound and the epoxy resin have good solubility and compatibility, so it can be used as an ink as it is, or various components can be freely added to correspond to various ink forms. As a result, it has become possible to respond to various purposes of use.

The reason why spirooxazine compounds have good solubility and compatibility with epoxy resins is unknown, but spirooxazine compounds are usually unstable as inks because they tend to crystallize. However, when a spirooxazine compound is used in combination with an epoxy resin, the epoxy group in the epoxy resin almost eliminates the ability of the spirooxazine compound to crystallize, and as a result, the spirooxazine compound is not uniform in its molecular state among various ink components. This is thought to be because it has become able to exist stably.

The epoxy resin mentioned here can be used regardless of whether it is an aliphatic or aromatic compound as long as it has an epoxy group in the molecule.
Furthermore, compounds that undergo a ring-opening reaction with an epoxy resin using a suitable curing agent to form beads are also naturally included.

The spirooxazine compound used in the present invention is usually colorless or light-colored and has the property of developing color when irradiated with light and then returning to its original color when shielded from light.

Next, specific examples of spirooxazine compounds will be shown.

Next, when the above-mentioned colored or discolored photochromic ink was left in a dark place, it returned to its colorless or original color tone, and had the ability to repeat colored or discolored depending on the presence or absence of light.

(Examples) Next, the present invention will be explained by examples, but these do not limit the present invention. Parts in the examples are parts by weight.

Example I Photorome I (manufactured by Toshin Chemical ■, spironaphthoxazine) 3 parts Adeka Resin EP-4100 (manufactured by Asahi Denka Kogyo ■, epoxy resin) 10 parts The above components were heated and stirred to obtain a colorless and transparent photochromin ink. .

By using an epoxy resin in combination with a spirooxazine compound, a photochromic ink with high concentration of the spirooxazine compound and good stability was created.

This photochromic ink was filled into a ballpoint pen and written on a notebook to obtain a colorless writing material. When this writing material was exposed to sunlight for 5 seconds or more, it developed a blue color. When this colored product was left in a dark place for 1 to 2 minutes, it returned to its original colorless state.

Although color development and decolorization were repeated 200 times, almost no deterioration in performance was observed.

Example 2 Photorome II (manufactured by Toshin Chemical ■, spironaphthoxazine) 3 parts Adekal resin f! P-4000 (manufactured by Asahi Denka Kogyo ■, epoxy resin) 10 parts Oil Pink #3
12 (manufactured by Orient Kagakujin, red dye) 0.3 parts The above components were heated and stirred to obtain a red photochromin ink.

This photochromic ink was filled into a ballpoint pen and written on a notebook to obtain a pale red writing.

When this writing material was exposed to sunlight for 5 seconds or more, it turned purple. When this discolored product was left in a dark place for 1 to 2 minutes, it returned to its original pale red color. Although the discoloration and discoloration were repeated 200 times, almost no deterioration in performance was observed.

Example 3 Photorome III (manufactured by Toshin Chemical ■,
spirophenanthrooxazine) 4 parts Adeka Resin BP-4300 (manufactured by Asahi Denka Kogyo ■, epoxy resin) 10 parts Oil Yellow #
107 (manufactured by Orient Kagaku ■, yellow dye) 0.3 parts Polyvinylpyrrolidone resin 3 parts Benzyl alcohol 4 parts The above components were heated and stirred to obtain a yellow photochromic ink.

This photochromic ink was filled into a ballpoint pen and written on a notebook to obtain pale yellow writing.

When this writing material was exposed to sunlight for 5 seconds or more, it turned green. When this discolored product was left in a dark place for 1 to 2 minutes, it returned to its original pale red color. Although the discoloration and discoloration were repeated 200 times, almost no deterioration in performance was observed.

Example 4 Photorome III 3 parts Denacol EX-421 (manufactured by Nagashio Sangyo ■, epoxy resin) 7 parts The above components were heated and stirred to obtain a colorless and transparent photochromin ink.

This photochromin ink was impregnated into a fired body of boron nitride (porosity: 25%, 0.5 mmφ) to obtain a white core. I wrote on a notebook using this lead to obtain a colorless writing material. When this writing material was exposed to sunlight for 5 seconds, it developed a blue color. When this colored product was left in a dark place for 1 to 2 minutes, it returned to its original colorless state. Although color development and decolorization were repeated 200 times, almost no deterioration in performance was observed.

Example 5 Photorome II
l part adeka resin EP
-41003 parts Amizole LME (manufactured by Yoken Fine Chemical ■, wax) 15 parts The above components were heated and melted, and then cooled to room temperature to obtain a solid colorless photochromic ink (stick).

Colorless writing written with this photochromin ink turned blue when exposed to sunlight for 5 seconds. When this colored product was left in a dark place for 1 to 2 minutes, it returned to its original colorless state.

Although color development and decolorization were repeated 200 times, almost no deterioration in performance was observed.

Example 6 Photorome I 1 part Adeka Resin EP-4000 10 parts Epomate B-001 (manufactured by Mitsubishi Yuka ■, epoxy curing agent) 4 parts Cellosolve acetate 2.5 parts The above components were stirred and melted to produce a photochromin ink for screen printing. Obtained.

Screen printing was performed on a glass plate or a PVC sheet using this ink, and the ink was cured at 40° C. for one day to obtain a colorless printed matter. When this print is exposed to sunlight for 5 seconds,
It turned blue. When this colored product was left in a dark place for 1 to 2 minutes, it returned to its original colorless state and was repeated 200 times, but almost no deterioration in performance was observed.

Example 7 Photoros+e IO,5
Part Tetron No. 900 Medium (manufactured by Jujo Kako ■, screen ink) 10 parts Tenacol Ex-4211 parts The above components were thoroughly stirred to obtain a photochromic ink for screen printing.

Screen printing was performed on a polyester sheet using this ink to obtain a colorless printed matter. This print developed a blue color when exposed to sunlight for 5 seconds. If you leave this colored material in a dark place, it will return to its original colorless state.
Although the test was repeated several times, almost no performance deterioration was observed.

Example 8 Photorose I 1 part New Daicure OL Medium (manufactured by Dainippon Ink Chemical ■, off-cent ink) 100 parts Buna: -LE EX-
4211 parts The above components were thoroughly stirred to obtain a photochromic ink for offset printing.

Offset printing was performed on a polyester sheet using this ink, and the light-colored printed matter was cured by ultraviolet light. This print developed a blue color when exposed to sunlight for 5 seconds.

When this colored product was left in a dark place for 1 to 2 minutes, the color returned to its original light color and was repeated 200 times, but almost no deterioration in performance was observed.

Example 9 Photorome I O, 4 parts CAB 381-05 (manufactured by Nagashio Sangyo ■, cellulose acetate butyrate) 3.6 parts Bunacol EX-921 (manufactured by Nagashio Sangyo ■, epoxy resin) 0.4 parts CR-50 (Ishihara Made by Sangyo ■, titanium oxide) 0.5 parts ethyl acetate 5 parts butyl acetate
16 parts ethyl cellosolve
5 parts The above components were thoroughly stirred and dispersed to obtain a photochromin ink for paint.

This paint was applied to wood, plastic, nails, etc. to obtain a white coated product. This coating turned blue when exposed to sunlight for 5 seconds. When this discolored product was left in a dark place for 1 to 2 minutes, it returned to its original white color.

Although the discoloration and discoloration were repeated 200 times, almost no deterioration in performance was observed.

Example 10 Photorome 1 0.4 part C
AB 381-05 3.6 parts Alumina C (manufactured by Nippon Aerosil ■, Alumina) 0.1 part Ethyl acetate 12 parts Butyl acetate 5 parts Ethyl cellosolve
Three parts of the above components were thoroughly stirred and dispersed to obtain a photochromin ink for gravure printing.

Gravure printing was performed on high-quality paper using this photochromic ink to obtain colorless printed matter. When this printed material was exposed to sunlight for 5 seconds, it developed a blue color. When this colored material was left in a dark place for 1 to 2 minutes, it returned to its original colorless state. The colorless process was repeated 200 times, but there was no performance deterioration. It was hardly noticed.

(Effects of the Invention) The photochromic ink of the present invention can be applied to uses that take advantage of the durability of repeated color development and fading. For example, it can now be applied to decorative materials, printed advertisements, daily necessities, toys, educational materials, and other applications that take advantage of its diverse, fun, and magical characteristics.

Claims (1)

[Claims] Spirooxazine compound general formula [I] represented by the following general formula [I] or general formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ General formula [II] ▲Mathematical formulas, chemical formulas, There are tables, etc. ▼ (Here, R_1 and R_2 represent a hydrogen atom, a chlorine atom, a methyl group, an ethyl group, a propyl group, and a methoxy group.) Photochromic ink whose essential components are epoxy resin and epoxy resin.