SU1254416A1 - Method of manufacturing photopolymeric printing plates - Google Patents

Abstract

The invention relates to the printing industry for producing printed products and improves productivity by reducing the duration of the irradiation. To do this, immediately before the pre-irradiation of the photopolymerization plate is passed between two rotating metallic rollers, the gap between which is 15-50 MKNj less than the plate thickness, the friction of the rolls rotation is 1.01-1.25, and the linear speed of movement the plate when passing between the rollers is 0.05-1 k / min. By passing the photopolymerizable plate through the rolls, the photosensitive layer is compacted and the microcapsle formed, as in the process of forming a layer from a photopolymerizable solution, is destroyed. As a result, the original photosensitivity of the photopolymerizable plates is restored and it is possible to normalize the technological process out of production. production of photopolymer printing forms. 1 table. i С

Description

The invention relates to a method for producing photoplexing printing forms that are used in the printing industry to produce printed products.

The purpose of the invention is to increase productivity by reducing the duration of irradiation.

The essence of the method lies in the fact that immediately before carrying out the pre-irradiation the photopolymerization plate is passed between two rotates with different speed with metal rollers, the gap between them being 15-50 µm less than the thickness of the photopolymerizable plate, the friction of the shaft rotation is 1.01-1.25 and the linear speed of the plate movement during the passage between the rolls of 0.05-1.0 m / min. By passing the photopolymerzukiceis plate through the rolls, the photosensitive layer is compacted and the microcapillaries formed during the formation of the layer from the photopolymerisation solution (its composition and during the storage of the plates as a result of evaporation of residual solvents) are destroyed. This leads to a decrease in the concentration of dissolved molecular oxygen in the layer and reduce the rate of diffusion of oxygen in the air deep into the photopolymerizable layer during pre-irradiation. As a result The original photosensitivity of the photopolarizing plates, lost by them during storage, is restored, and it is possible to normalize the physiological characteristics of the process of making photopolymer printing plates.

Example 1. From a photopolymerizable plate, Celloph-2 type B (TU 6-17-1841-81), 5% of which is a layer of a photopolymerizable composition based on cellulose acetosuccinate 0.7 mm thick and fixed on a metal substrate with a thickness of 0.25, cut samples format, 10 X 100 and 80 X 100 mm.

Samples of 10 x 100 mm format are used to determine the induction period of the photopolymerizable plate.

The induction period is determined by the trace / w1. The sample is placed on the installation, equipped with fluorescent LUFT-60, set10

15

20

-25 2544162

 180 mm from the photopolymerizable plate. A flap is installed on the plate to protect it from light. The damper is equipped with a mechanism of movement with a speed V between the lamps and the sample, and a light filter is installed — a floor film of the TAC. The lamps and flap movement are switched on, gradually opening the sample of the photopolymerizable plate to light. At the end of the irradiation, the sample is removed from the installation, placed in a washer and washed out with a 0.15% aqueous solution of sodium hydroxide for 12 minutes, then removed from the washer, washed with water and dried under natural conditions. Using a caliper, measure the length of the extruded zone on sample S and determine

induction period of the plate according to the formula:

-g - -§- ON - V

The thickness of the photopolymerizable vdx plates of the plates is determined using a micrometer.

Set the gap between the rollers. 30 microns less than the thickness of the photopolymerizable plate;

the friction between the rolls is equal to 1.1, the sample movement speed is 0.5 m / min, under these conditions the sample of the photopolymerizable plate is passed between the rolls and the induction period is determined as described above.

A sample of a photopolymerizable plate with a format of 80 x 100 mm is passed under the described conditions through the rolls and pre-irradiated with LUFT-60 lamps set at a distance of 180 mm from the photopolymerizable plate through a polaroid film TA1 The pre-irradiation time is 3 minutes.

The optimal exposure time is determined experimentally by exposing samples prepared as described above for various times and the quality is obtained visually.

photopolymer printing plates.

The washout time is 12 minutes, to completely remove unpolymerized photopolymerization from the gaps; 1; 2x of compolation.

To determine the characteristics of the resulting photopolymer printed

3125A

Forms are prepared samples containing the world of resolution, the world of excretion, separately standing points with a diameter of 200 µm, as well as test forms to study the specific 5 resistance of the printing elements to shear.

The resolution is determined by viewing the world through a magnifying glass. increase x 10. About

Influencing ability is determined by measuring the dimensions of the smallest elements of the world using the optical system of the 1ТГГ-3 instrument.

The angle at the base of the printing element is measured by means of a protractor on a point profile with a diameter of 200 µm, drawn by the CH-2 clock projector.

The resistivity of the printing elements 20 shear is determined on a tensile machine.

As a result of the tests, the following results were obtained: the thickness of the photopolymerizable plate 25 is 1.025 mm, the induction period before the roller treatment is 4.5 minutes, the gap between the rolls is 0.995 mm, the induction period after the roller treatment is 3.5 hours, the pre-irradiation time,. 3 min, the optimal exposure time is 7 min, the resolution is 100, the evolving power is 40 µm, the angle at the base of the printing elements is 70, the resistivity of the printing elements is a shift of 27 MPa.

In parallel, an image is prepared. from the same plate by the prototype method, i.e., without passing the plate between. rolls and test them as described above. As a result of the tests, the following results were obtained: thickness photp16 .4

polymerizing layer 1.025 mm, an induction period of 4.5 mn, a pre-irradiation time of 3 min, an optimal exposure time of 12 min, a resolution of 100, an evolving power of 70 µm, an angle at the base of the printing elements 68, a specific resistance of the printed elements of the shear of 27 MPa.

Example 2-5. Samples were cut out from photopolymerizable plates taken from different batches with different shelf life and tested as described in Example 1.

The characteristics of the samples of photoiolimizing plates according to the examples, the modes of their processing by rolls, the mode of the technological process of making photopolymer plates and their quality indicators are shown in the table.

Claims (1)

Invention Formula A method of manufacturing photopolymer plates, including pre-irradiation, exposure through negative, leaching, washing and drying, characterized in that, in order to improve performance by reducing the duration of irradiation of the process, immediately before the pre-irradiation, the plate is passed between two rotating metal rolls, the gap between them is 15-50 µm less than the trough plate, the friction of rotation of the rolls is 1.01-1.25, and the linear speed movement of the plate when passing between the rolls is 0.05 to 1 m / min. Table continuation,