SU766899A1 - Method of making copying material - Google Patents

Description

(54) METHOD OF MAKING COPIER MATERIAL

I

The invention relates to papermaking and can be used in the manufacture of a diazo-type copying material for the production of blueprints by contact copying.

Methods are known for the manufacture of copier materials by applying various photosensitive layers to a paper substrate 1.

The copier materials obtained by such methods have low mechanical strength.

There is also known a method for manufacturing a multilayer copying material by successively applying a polyethylene layer onto the paper substrate, and then the photosensitive layer 2.

However, the homogeneous structure of the photosensitive layer, which forms when diazo-solution is applied to the poorly developed surface of the polyethylene layer, leads to a sharp decrease in the rate of development of the copier, which makes it difficult to use it.

In this case, the polyethylene layer is applied to the base paper in order to facilitate the adjustment of the copies obtained.

The closest to the proposed invention is a method of making a copying material by coating a paper substrate with a photosensitive layer based on a diazo compound from the class of p-phenylenediamines and resorcinol 3.

The method is carried out on a watering machine by known means. A diazo type solution is prepared by mixing the diazo compound solution with a solution of resorcinol and stabilizing components.

The disadvantages of this method are a significant decrease in the mechanical strength of the paper substrate when the photosensitive layer is applied to it, caused by the hydrolytic effect of the components of the photosensitive layer on the cellulosic material of the paper substrate, and the insufficient preservation of the copier material.

The purpose of the invention is to reduce the hydrolytic effect of the photosensitive layer on the cellulosic material of the paper substrate while at the same time increasing the mechanical strength and maintaining the copy material. The goal is achieved by the fact that before applying the photosensitive layer on the paper substrate it is previously subjected to heat treatment at 80-120 ° C, the net side of the paper substrate is treated with polyethylene melt, and the top one with an aqueous solution of 0.001-0 antioxidant, then on the side of the paper treated with antioxidant apply a photosensitive layer. Applying a polyethylene layer to the net side of the paper substrate reduces the mechanical strength loss of the copier material by reducing the hydrolytic effect of the photosensitive layer on the cellulosic material of the paper substrate due to the screening of the cellulosic fibers with hydrophobic polyethylene particles. The preliminary heat treatment of the paper substrate, by increasing the pore size, leads to an improvement in the penetration of the polyethylene melt into the paper substrate, which contributes to shielding a larger amount of cellulose fibers and a greater reduction in the mechanical strength loss of the copier. However, deposition of polyethylene melt on the grid side of the paper substrate due to internal stresses arising in this case leads to curl of the copier material, which makes its practical use difficult. Heat treatment of the paper substrate, increasing the linear dimensions of the latter, compensates for the stresses that arise when a melt of polyethylene is applied to the paper substrate, and eliminates the curl of the copier material. On the other hand, the polyethylene layer, protecting the cellulose fibers from the components of the photosensitive layer, is itself exposed to the latter. To eliminate this effect, as well as to reduce the negative effect of the photosensitive layer, the cellulose fibers unprotected by polyethylene are applied to the upper side of the paper substrate with an antioxidant layer. Copier material is produced by applying a melt of polyethylene on the grid side of a paper substrate, which is thermally pretreated in the drying part of the machine, on an extrusion-lamination machine. Then, an antioxidant solution is applied first to the top (front) side of the paper substrate on a watering machine by known methods under normal conditions, and then a diazo-type solution is applied. A crystalline violet dye is preferably used as an antioxidant. Example 1. A paper substrate with a paper mass of 1 m 70 g, consisting of cellulose AP-kaolin and optical bleach, glued with rosin glue, is taken. A 0.001% antioxidant solution is prepared, a solution of crystalline violet in water at 60-80 ° C. To prepare a diazo-type solution in 100 liters of water at a temperature not higher than 35 ° C, 3.07 kg of p-diazodiethylaniline (solution A) is dissolved; In a 100 liter of water at 15–20 ° C, 0.88 kg of resorcinol, 2 kg of citric acid, 14 kg of zinc chloride and 5 kg of thiourea (solution B) are successively dissolved in a sequence of 15–20 ° C; solution A is poured into solution B while stirring. The paper substrate is thermally treated in the drying part of the extrusion-laminating machine at 80 ° C, then a polyethylene layer weighing 60 g / m is applied to the grid side of the paper substrate on the same side the top side is applied first with a 0.001% antioxidant solution, and then with a diazo-type solution. The copying material is tested in accordance with GOST 13525.2-68 on an I-2-1 instrument with a tensile force of 0.8 kg. EXAMPLE 2 Copier material was made analogously to Example I, except that a 0.02% antioxidant solution was used. Example 3. The copying material was made analogously to example 1, except that a polyethylene layer weighing 80 g / m was applied to the grid side of the paper substrate, and the paper substrate was thermally treated at 120 ° C. Example 4. A copying material was made analogously to example 3, except for using a 0.02 ° / antioxidant solution. Example 5. For comparison, a copying material is obtained according to a known method. A paper substrate with a mass of 70 g is taken, consisting of magicians with an area of 1 made of cellulose А-П, kaolin and optical bleach, glued with rosin glue.

A diazo solution is prepared and applied to a paper backing as in Example 1.

Copy material is tested in accordance with GOST 13525.2-68 on

an I-2-1 instrument with a tensile force of 0.8 kg.

The results of testing the obtained copier are shown in the table.

As can be seen from the table, the use of additional layers: polyethylene and antioxidant, in combination with the preliminary heat treatment of the paper substrate, makes it possible to obtain a copying material with high mechanical strength, 3-5 times higher than the strength of the known copying material and enhanced preservation.

Increasing the heat treatment temperature and the concentration of the antioxidant layer, which reduces the hydrolytic effect of the components of the photosensitive layer on the cellulosic material of the paper substrate, leads to an increase in the mechanical strength of the copying material — the resistance to fracture has increased from 800 to 960 and from 1400 to 1680 double bends.

Claims (3)

1. Dinaburg MS. Light-sensitive diazocompounds and their application. M.-L., “Himi, 1964, p. 48-53. 2. Patent of Great Britain No. 1341749, 0 кл. G 03 C 1/52, pub. 1973. 3. The patent of Germany No. 1004919 cl. G 03 from 1/58, published. 1957 (prototype).