SU1175370A3 - Method of generating acid-resisting copy on surface - Google Patents

Abstract

1. METHOD OF FORMATION OF ACID-RESISTANT COPIES FOR -. TOP, which includes coating a surface with a photosensitive resist containing caseinate, photosensitization in the form of alkaline bichromate and water, drying this coating, exposing the dried coating, developing the exposed coating to remove areas that are not exposed to exposure, and hardening the coating. acid resistance, characterized in that, in order to reduce exposure time by improving photosensitivity, Photosensitive resist pH 5.8-7.0 and density 1.028-1.036 g / cm, additionally (L containing dispersing agent, while alkaline caseinate is used in the amount of 6-12 wt.%, and the proportion of alkaline bichromate is 10 -30% by weight of alkaline caseinate. T 41 01 with vl

Description

 3

t.}

2. The method according to claim 1, of which the photosensitive resist additionally contains tetraborate sodium in the amount of 18-35% by weight of alkaline caseinate.

3. A method according to claims 1 and 2, characterized in that bichromate a1 4 is used as the alkaline dichromate.

4. The method according to paragraphs. 1-3, about the fact that. Caseinate iat rv is used as alkaline casein.

The invention relates to methods for forming an acid-resistant copy on a metal surface and can be used in a shadow mask etching technique for kinescopes of color television sets.

The aim of the invention is to reduce the exposure time by improving the sensitivity of the composition used.

Figure 1 shows the metal sheet after etching in accordance with the proposed method, view in plan; Figures 2-6 are a flowchart of the proposed method.

The blank 1 of the shadow mask (which is then used in the kinescope) is made in a metal sheet 2 containing a series of blanks etched along the edges 3 leaving enough points (not shown) in an amount sufficient to hold the blank 1 in place in sheet 2. The blank 1 comprises an apertured central part 4, delimited by dotted line 5, and an edge 6 without holes (in some embodiments, holes can be etched in it). Acid-resistant mines, made according to the proposed method, can be used for etching holes in the central part 4,

The mask blank 1 is etched in a sheet of normal carbon or low carbon cold rolled steel with a thickness. 0.10-0.25 mm. Sheets can be subjected to etching from another material, for example, from nickel steel.

or copper-nickel alloy. Sheet 2 goes through various operations, including cleaning it, making acid-resistant copies on it,

etching the lisga before receiving the holes and making copies from it. Then, the workpiece 1 is pulled out of sheet 2, subjected to heat treatment (hardened), roller dressing, press stamping and blackening to obtain masks for a kinescope of a color television set.

FIG. 2-6 show the sequence of operations for obtaining

round hole in the central part of 4 strips with a thickness of 0.15 mm. Sheet 2 on both surfaces is coated with a composition made according to the inventive method.

After drying in air, light-sensitive coatings 7 and 8 are obtained in the form of sodium caseinate sensitized by dichromate (Fig. 2). After drying the coated

The strip is placed between two translucent patterns 9 and 10 (Fig. 3), in which chrome or nickel coating can be used on the inner surfaces of glass plates 11 and 12, so that the templates are in direct contact with coatings 7 and 8 The photomask 9 has a round shape with a size on the outer diameter of 0.13 mm, and the photomask 10-0.4 mm. The center lines of the photomasks may coincide or be shifted one relative to another. Then cover 7 and 8 are subjected to

radiation, for example

from the arc source and this radiation passes through the glass plates 11 and 12 to the coatings 7 and 8, which under its influence become insoluble, with the exception of areas covered with photomasks. After appropriate exposure, the exposure is stopped and the photomasks are removed. The coatings can be jet washed, for example, with water or other water-based solvent to remove unexposed areas. After the appearance (Fig. 4), copies are formed on the surfaces of sheet 2, formed by coatings 7 having openings 13 and 14. Then the copies are hardened in air at 275-325 0 to impart etch resistance. The sheet is then etched (in Figure 5, the protected sheet is copied at the beginning of etching, and in Figure 6 at the end), which is carried out in the usual manner using an aqueous solution of ferric chloride with hydrochloric acid. To maintain the strength of the solution, adjustable amounts of chlorine gas are introduced into it. Upon completion of the etching of the coating by COPIES; the sheet is washed with water to remove "residual solution, acid-resistant coatings 7 and 8 are removed by spraying an aqueous solution of sodium hydroxide at 50-80 ° C, after which the sheet is washed in water and dried. Table 1 shows the compositions (in grams) and the properties of the compositions that can be applied in the proposed method. Composition 1 can be used in laboratory conditions, and Compositions 2–4 can be used in industry. The compositions are prepared as follows. Composition 1. Sodium caseinate is dissolved with vigorous stirring in 800 l of water with a temperature of 50 ° C. A dispersing agent, triton, is added. Borax (.) Is dissolved in 100 ml of deionized water, this solution is heated before and slowly added to a solution of sodium caseinate, then a solution of a bactericide, such as phenolic, is added thereto in 100 ml of deionized water. The solution is cooled to 20-23 C. 704 Dissolve the ammonium bichromate HS420 in 200 ml of deionized water and add this solution to the sodium caseinate solution. Composition 2, Dissolve borax in 4 liters of hot () deionized water and add this solution to 32 liters of hot (80 ° C) deionized water. A dispersing agent (e.g., sulframine 4010) is added to this solution and stirred for about 2 minutes. Continuing to stir, add sodium caseinate. Then the bactericide is added, cooled to 20-23 ° C, the solution () in 5 ml of deionized water is added at the required density. Composition 3. Dissolve borax in 33.5 liters of hot (55-85 ° C) water with vigorous stirring and sodium caseinate is added slowly. When lumps appear, the addition of caseinate is stopped until the starting material is dissolved. Stirring is continued until caseinate is completely dissolved, the solution temperature is 25 ± 2 ° C. Ammonium dichromate, dissolved in 4.1 l of deionized water, is added at room temperature and stirred for 5 minutes. A solution of sulframine 4010 in 0.5 liters of deionized water is added, then water is added to the desired density. Composition 4. Prepared similarly to composition 3. An increase in the pH of the coating due to the higher concentration of borax is compensated for by the increased content of ammonium bichromate. In the proposed composition, you can use any alkaline caseinate. Sodium caseinate is more preferable than potassium caseinate or ammonium, in particular, due to its better solubility in water. In order to realize maximum photosensitivity in a dry coating, it is desirable that alkaline caseinates have a molecular weight above 250,000. The pH of the composition is determined by obtaining the required photosensitivity. The density of the composition determines the thickness of the coating, which also depends on the temperature in the coating chamber. Density

from 1.028 to 1.032 g / cm provides coatings with a thickness of 1-5 microns.

-. - -.

Ammonium dichromate compared to sodium and potassium bichromates provides coatings with the highest sensitivity (exposure time is equivalent to the exposure time of fish glue sensations sensitized by ammonium dichromate), and also shows a lower tendency for crystallization during the drying process.

The dispersing agent may be selected from a large group of known dispersing agents. The bactericide may not be used if the prepared composition is used for three days.

 The temperature in the tunnel chamber is recommended to be maintained in the range of 51.7 -71. If the temperature falls below 37.8 ° C, ammonium bichromate may appear, causing masks to reject. The kiln for a bitch should provide a top and bottom sensation of the temperature band in the order of 90 ° C when measured with a surface pyrometer. Viscosity at 21.1 С, сП 11.5 1.032 Density at 21.2 С 6.6 РН Weight ratio of auger / ka. Zeinate

Sodium tetraborate (borax) provides a faster process. Borax gives greater solubility to alkali metal caseinates, especially sodium caseinate. In the absence of a drill, the coating may appear poorly, lower linear velocities may be required, and higher temperatures of manifestation, which reduces productivity. Optimum temperature of occurrence 37 ,.

The thickness of the coating on the metal sheet is an important parameter in the manufacture of masks. If the layer is too thin (less than 1 micron), etching will be non-uniform and cause defects in the masks, if it is too thick (over 25 microns) - the exposure time increases, mechanical problems arise, the difficulty of ensuring the sharpness of the edge is poor uniformity of the mask.

Table 2 shows typical thicknesses for coatings containing sodium caseinate and fish glue.

Preferred hardening temperatures are 275-325 ° C. Coating is subjected to hardening at a temperature of 305 ° C and most effectively removed after etching when washing with caustic soda.

Table 1 7.59.5 1.0301.030 6.86.8

way down

way down

2-, 5-4,8

///// //

   1J 1-L Sr, /

777x7Gx

Fig.Z

Fig., 5

f. ||

/ h

6

table 2

one

1-1,7

2-2.5

1.7

3

/.

/

7

g

8 12

/

K f

one

eight

Claims (4)

1. METHOD FOR ACID-RESISTANT COPY FORMATION ON THE SURFACE, including applying a photosensitive resist containing caseinate to the surface of the coating, light-sensitizing alkaline dichromate and water, drying this coating, exposing the dried coating, developing an exposed coating to remove areas that have not been exposed to exposure, exposed and exposed to exposure coatings for imparting acid resistance to other areas, characterized in that, in order to reduce exposure time by mproving photosensitivity, a photosensitive resist is used pH 5,8-7,0 and a density of 1,028-1,036 g / cm ^Oe, further comprising a dispersant, wherein as the alkaline caseinate caseinate used in an amount of 6-12 wt.%, and the proportion of alkali dichromate accounts for 10-30% by weight of alkaline caseinate. SU., 1175370 2. The method according to claim 1, characterized in that the photosensitive resist further comprises sodium tetraborate in an amount of 18-35% by weight of alkaline caseinate. 3. The method according to PP. 1 and 2, characterized in that ammonium dichromate is used as alkaline dichromate. 4. The method according to PP. 1-3.0 'who’s having that. Sodium caseinate is used as alkaline casein.