JPS6341754B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to desensitizers. More particularly, the present invention relates to a desensitizer for suppressing or blocking the coloring function in carbonless pressure-sensitive copying paper using an electron-accepting compound or solid acid for coloring a colorless coloring agent. Generally, pressure-sensitive copying paper consists of paper coated with an electron-donating leuco dye encapsulated in fine capsules and paper coated with an electron-accepting substance or solid acid. When pressurized, the capsule in the pressurized area is destroyed and the leuco dye develops color. The desensitizer is used for the purpose of suppressing or preventing color development by applying it in advance to areas where color development is not required on either the surface coated with the electron-accepting substance or the electron-donating substance. Capsules containing electron-accepting substances and electron-donating substances are uniformly applied to the entire surface of the paper, so it is widely used to apply a desensitizer to either side of the paper using a printing machine to remove unnecessary areas. It is. Clay minerals such as acid clay, bentonite, attapulgide, zeolite, and kaolin are known as electron-accepting solid acids. Also, known electron-donating color formers include crystal violet lactone, rhodamine anilinolactone, malachite green lactone, benzoyl leucomethylene blue, Michler's hydrol, and N-allyl leuco auramine. Conventionally known desensitizers include Japanese Patent Publication No. 46-29546;
Polyhydroxy compounds such as those found in JP-A-1964-19647, JP-A-48-6805, etc.;
27255, amine compounds such as those found in Japanese Patent Publication No. 1972-21448, Japanese Patent Publication No. 33-3921, Japanese Patent Publication No. 1973-
These include hetero compounds as seen in JP-A No. 15513, and polyether compounds as shown in JP-A-156010-1983 and JP-A-97511-A. Most of these desensitizers are strongly hydrophilic substances and are therefore printed by letterpress printing presses.
It was difficult to use printing machines other than letterpress printing machines. The ability to print desensitizers on printing presses other than letterpress printing presses provides various advantages. For example, if it became possible to print with an offset lithographic printing machine, compared to printing with a conventional letterpress printing machine, (1) the ink would be evenly distributed because it is offset, and (2) the printing pressure would be applied to the entire surface of the plate. Because it applies evenly, there is less destruction of paper microcapsules (3) Plate making is easy (4) Printing speed is high (5) Printing has a beautiful finish (6) Printing machines are widely used by the general public Therefore, advantages such as high demand can be expected. Attempts have been made to print desensitizers using wet offset printing machines, for example, using alkoxyl nucleophilic compounds as desensitizers, but conventional desensitizers have poor printability and bleed resistance, and The desensitization effect was also not sufficient. Although attempts have recently been made to print desensitizers by waterless lithographic printing, there has been a strong desire for a desensitizer that can be printed using conventional wet offset printing machines. As a result of intensive research into desensitizers that can be printed not only on letterpress printing machines but also on printing machines other than letterpress printing machines, the present inventors came to invent the desensitizer with excellent desensitizing effects of the present invention. It is something. That is, the present invention is a desensitizer comprising a product obtained by adding alkylene oxide or styrene oxide to a resin acid-reduced alcohol. The present invention has an excellent desensitizing effect on pressure-sensitive copying paper such as carbonless copying paper, and there is no bleeding of desensitizer into unprinted areas, and the present invention is applicable to printing methods other than letterpress printing as well as letterpress printing. In particular, it has excellent printability during wet offset printing, and does not have the problems of yellowing and odor that are the drawbacks of conventional desensitizers.
The present invention provides a desensitizer that is easy to synthesize. The printing ink using the desensitizer according to the present invention can be printed by various printing methods such as offset printing and flexographic printing in addition to conventional letterpress printing.
It has various advantages not available with conventional desensitized inks for letterpress printing. For example, when a printing ink made using the desensitizer according to the present invention is printed using a wet offset printing machine, the printing effect is excellent and the drying properties are also particularly excellent, making it possible to speed up printing. Therefore, plate making is easy and a large amount of labor can be saved. When a desensitizer is used in accordance with the present invention and printed with ink, a printed matter with good writability and inconspicuous printing can be obtained. The resin acid-reduced alcohol related to the present invention is
Obtained by reducing resin acid, which is a component of natural resin,
Resin acid-reduced alcohol obtained from rosin, called rosin alcohol, is well known. Since rosin has a resin containing abietic acid as its main component, it is known that the main component of resin acid alcohol obtained from rosin is hydroabiethyl alcohol. The alkylene oxides used in the present invention include ethylene oxide, propylene oxide,
Examples include butylene oxide and mixtures thereof, but ethylene oxide, propylene oxide, or mixtures thereof are preferred from the viewpoint of desensitizing effect. The number of moles of alkylene oxide or styrene oxide added is most preferably 1 to 100 moles in the case of ethylene oxide and propylene oxide, and 1 to 20 moles in the case of styrene oxide, and more than this number of moles or If it is less than that, the printing effect and desensitization effect tend to deteriorate. Depending on the purpose, desired additives such as a drying accelerator, other varnishes, solvents, pigments, etc. can be appropriately added to the printing ink using the desensitizer of the present invention to an extent that does not inhibit the desensitizing effect. The present invention will be explained below with reference to Examples. Example 1 100 g of Avitol (resin acid-reduced alcohol manufactured by Hercules, USA) (contains about 0.28 mole of hydroxyl group)
20 parts by weight of titanium oxide (rutile) and 10 parts by weight of mineral oil were mixed with 60 parts by weight of an addition reaction product of 163 g (2.8 moles) of propylene oxide and propylene oxide, and the mixture was kneaded in a three-roll mill to prepare a desensitizing ink. The obtained desensitized inks were printed on commercially available carbonless pressure-sensitive copy paper using an offset printing tester so that the coating amount was 5.0 g/m ² . Desensitizing inks containing the following addition reaction products were prepared and printed in the same manner.

[Table] Comparative example 1 Polyethylene glycol (molecular weight approximately 400)
(PEG400, manufactured by Sanyo Chemical Industries, Ltd., hydroxyl value 250) 30
A desensitizing ink was prepared by uniformly mixing 30 parts by weight of linseed oil-modified alkyd resin, 10 parts by weight of mineral oil, and 30 parts by weight of titanium oxide (rutile) using a three-roller mill. The obtained desensitized ink was printed using an offset printing tester on the inner sheet of commercially available carbonless pressure-sensitive copying paper so that the coating amount was 5.0 g/m ² . Comparative Example 2 To 80 parts by weight of a varnish consisting of 60% by weight of ethoxylated nonylphenol (desensitizer), which is a type of alkoxylated nucleophilic compound, and 40% by weight of rosin esterified with glycerin, 3 parts by weight of micronized silica,
A desensitizing ink was prepared by kneading 12 parts by weight of calcium carbonate and 5 parts by weight of titanium oxide (rutile) in a three-roll mill. The obtained desensitized ink was printed in the same manner as in Comparative Example 1 on the inner sheet of commercially available carbonless pressure-sensitive copying paper. Next, test methods for desensitization effect, bleed resistance and offset printing suitability will be shown. [Test method] Desensitization effect test Using the above printing paper, 100
The desensitizing effect was tested by applying a load of 1.5 g and moving at a speed of 5 m per minute for copying (color development).
The results of the test are shown in Table 1, and the numerical values indicate the reflective visibility values (visual density abbreviation: Vis, D) measured with a microdensitometer.

【table】

[Table] Bleed resistance test The above printed material and non-desensitized carbonless pressure-sensitive copying paper were stacked together, a load of 10 g/cm ² was applied, and the paper was placed in a constant temperature and humidity room at a relative humidity of 90% and a temperature of 20°C. After being left for one month, a color development test was conducted on the printed matter and the non-desensitized carbonless pressure-sensitive copying paper. The results are shown in Table 2.

【table】

[Table] Offset printing suitability test Printing suitability was comprehensively judged by ease of printing using an offset printing tester. The results are shown in Table 3.

【table】

[Creation of printed matter]

The desensitizing inks obtained in Examples 19 and 20 and Comparative Example 3 were applied to inner sheets of commercially available carbonless pressure-sensitive copying paper using a flexographic printing tester at a coating amount of 4.0 g/m ² , respectively. I printed it to look like this. [Test Method] Using the obtained printed paper, desensitization effect and bleed resistance were tested by the same method as that used in Examples 1 to 18 and Comparative Examples 1 and 2. Regarding suitability for flexographic printing,
The ease of printing was comprehensively judged using a flexographic printing tester. The results of the desensitization effect test are shown in Table 4, the results of the bleed resistance test are shown in Table 5, and the results of the flexo printing aptitude test are shown in Table 6.

【table】

【table】

[Table] ○: Good △: Slightly poor
The results shown in Tables 1 to 6 show that the desensitizer according to the present invention is excellent in desensitizing effect, bleed resistance, suitability for offset printing, and suitability for flexographic printing.

Claims (1)

[Claims] 1. A desensitizer comprising a product obtained by adding alkylene oxide or styrene oxide to a resin acid-reduced alcohol.