CN1072367C - Improved photoresist material containing photosensitive component for cathode ray tube and its preparation method - Google Patents

Abstract

A photoresist coating is applied to the inner surface of a glass display screen panel of a Cathode Ray Tube (CRT) in the form of a substrate (matrix) having a plurality of spaced areas each surrounded by the black photoresist region using optical micro-development. Phosphors for producing the three primary colors red, green and blue are deposited in these spaced apart regions with the surrounding black photoresist to provide improved video image color contrast. After the photoresist material is deposited on the glass display screen panel, the photosensitive photoresist coating is cured by Ultraviolet (UV) light irradiation with a specific wavelength having a maximum intensity. The photosensitive component of the photoresist coating is selected to have maximum photosensitivity at the maximum intensity wavelength of the UV light source to provide a high quality black matrix to improve video impact image color contrast. The photosensitive component is characterized in that it comprises a ketone group.

Description

Improved photoresist material containing photosensitive component for cathode ray tube and its preparation method

The present invention relates generally to a video display screen of the cathode ray tube (CRT) type, and more particularly to an improved photoresist material for coating the inner surface of a glass display panel of a cathode ray tube to provide color contrast in video images .

Optical microlithography is a method widely used in screen processing of CRT glass display panels to produce red, green and blue primary color phosphors. This basic screen printing technique typically involves exposure of a photosensitive colloid, the exposed areas of which remain after development as insoluble. To improve color contrast, prior to phosphor screen processing, a micrographic technique is used to provide a pattern plan on the display screen in which areas not occupied by colored phosphors are painted in a process called "black matrixing". The upper layer of graphite ultra-fine powder. The phosphor screen processing method involves applying a photoresist material on the inner surface of the display screen. The photoresist typically includes polyvinylpyrrolidone (PVP), 4,4'-diazidestilbene-2,2'-disulfonic acid disodium salt, and water. Adhering the photoresist material to the CRT glass display screen has always had the problem of reduced yield. To overcome this problem, polyvinyl alcohol (PVA) is added to the photoresist. The addition of PVA provides two benefits. First, the adhesion between the photoresist material and the glass display panel is substantially improved. Second, adding PVA to the photoresist suppresses its oxygen content, thereby shortening the time it takes for the photoresist coating to harden upon exposure to UV light. However, several problems are encountered when PVA is added to PVP-containing photoresists. The first problem is the incompatibility between PVP and PVA, which will make it difficult for the coating after adding PVA to be applied on the glass display panel in the form of a film of uniform thickness. U.S. Patent Application No. 08/424,907 filed on April 19, 1995, titled "INPROVED PHOTORESIST FOR CATHODE RAY TUBES" (Taiwan Patent Application No. 85106291 filed on May 27, 1996, titled "Cathode Ray It is explained in the improved photoresist material and its preparation method"). The incompatibility problem between PVP and PVA was solved in the aforementioned patent application by adding vinylpyrrolidone-vinyl alcohol (VP-VA) copolymer to the mixture of organic binder and photoresist material.

Another problem encountered by commonly used photoresist materials is the water solubility and photosensitivity of disodium salt in photoresist materials. Typically, the limited aqueous solubility of disodium 4,4'-diazidostilbene-2,2'-disulfonate results in limited photosensitivity of the photoresist, resulting in poor video image color contrast. This problem has been explained in another patent application filed by the inventor of this case and the assignee of this case (case name "improved photoresist material with highly water-soluble photosensitive component for cathode ray tube and preparation method thereof), which provides A photoresist material that contains a better water-soluble photosensitive component, thus allowing a higher concentration of the photosensitive component to obtain a photoresist material with better photosensitivity.

After the photoresist material is applied on the inner surface of the CRT glass display panel, the photoresist material is irradiated with ultraviolet light (UV) of a specific wavelength to activate its photosensitive components to harden the photoresist layer. Another problem encountered with conventional photoresists arises from the nature of the photosensitive component of the photoresist and the UV light used for its curing. Generally speaking, mercury UV light sources with maximum intensity at 365nm, 405nm and 440nm are generally used in the aforementioned black matrix application. However, the photosensitive component of this photoresist (disodium 4,4'-diazidestilbene-2,2'-disulfonate) has a maximum photosensitivity at 335 nm. The difference between this maximum intensity and the wavelength of incident UV light at which the photoresist material is most photosensitive causes non-uniformity and irregularities in the photoresist coating, resulting in poor color contrast in the video image.

While this case illustrates the aforementioned limitations of the known technology, the present invention provides a photosensitive component in a photoresist coating that has improved photosensitivity to UV light incident thereon to activate and harden The coating improves the color contrast of video images on display panels.

Therefore, one object of the present invention is to provide an improved photoresist material for coating the inner surface of a glass display panel of an image display device such as a CRT.

Another object of the present invention is to provide a photoresist material for the inner surface of a glass display panel of a video display device, which provides a high degree of photosensitivity to improve the color contrast of a video image.

Yet another object of the present invention is to provide a photoresist for coating the inner surface of a CRT glass display panel, which has a photosensitive component that reacts in the presence of UV light used to harden the photoresist. Improved photosensitivity at the wavelength of maximum intensity.

The present invention is directed to the improvement of photoresist coatings on the interior surfaces of glass image display panels, wherein the photoresist coating includes a photosensitive component reactive to ultraviolet light incident thereon to harden the photoresist Coating, the incident UV light is characterized by having a maximum intensity at a specific wavelength, the improvement is the addition of a photosensitive component having a ketone group to the photoresist coating, the photosensitive component having a ketone group is characterized by By having a peak sensitivity at or near the maximum intensity of the incident UV light.

The appended claims set forth the novel features which characterize the invention. However, the invention itself and its further objects and advantages will be better understood with reference to the detailed description of a preferred embodiment and the accompanying drawings which, in accordance with the principles of the invention, have a glass display panel on the inner surface thereof A longitudinal cross-section of a CRT with a photoresist coating.

1 is a cross-sectional view of a CRT 10 having a phosphor-based photoresist coating 24 therein in accordance with the principles of the present invention. In the following discussion, the terms "display screen," "display panel," and "panel" are used interchangeably. CRT 10 includes a sealed glass envelope 12 having a front convex or display panel 14 , a rear neck portion 18 , and a central funnel portion 16 . The photoresist coating 24 comprises several discrete phosphorescent deposits or elements that emit light when an electron beam is incident thereon, thereby producing a video image on the display screen panel. The color CRT 10 contains three electron beams 22 directed toward and focused on the CRT glass display panel 14 . Located within the neck portion 18 of the CRT glass envelope 12 are several electron guns 20, typically arranged side by side, which emit electron beams 22 towards the display screen 14. These electron beams 22 are vertically and horizontally deflected by a mag-netic deflection yoke and pass together through a phosphor-based photoresist coating 24 . For simplicity, the magnetic deflection system is not shown in the figure. The shadow mask 26 is arranged at a certain distance from the phosphor screen 14. There are many separated slits for electron beams to pass through the shadow mask 26. There is a skirt portion 28 around the shadow mask 26.

The skirt portion 28 of the shadow mask is secured to mask mounting fixtures 30 around the shadow. The shadow mask assembly fixture 30 is attached to the inner surface of the CRT glass envelope 12, and may include conventional accessories and positioning structures, such as a mask frame and device springs, which are not shown in the figure for the sake of simplification. The shadow mask mounting fixture 30 can be attached to the inner surface of the CRT glass envelope 12 in a conventional manner, such as welding or glass fusing, and the shadow mask 26 can be attached to the mounting fixture in a conventional manner. Located on the outer surface of the display screen 14 is an antistatic/antireflective coating 32 .

As mentioned above, commonly used photoresist materials contain PVA, PVP, and photosensitive and disodium salts such as 4,4'-diazidostilbene-2,2'-disodium disulfonate, the latter has the following molecular formula Disodium 4,4′-diazide trans-stilbene-2,2′-disulfonate

This sodium salt has a maximum photosensitivity at 335nm. The UV light source used to harden the photoresist is generally a mercury water source, which is most intense at 365nm, 405nm and 440nm. Because the maximum photosensitivity of the disodium salt does not occur at the maximum intensity wavelength of the UV light source, the hardening of the photoresist coating is poor and the color contrast of the video image presented on the display panel is poor.

(360nm)2,2′-(1,5-五-3-酮基-1,4-二烯基)双(5-叠氮基苯磺酸)二钠

(356nm)2,6-二(对叠氮基亚苄基)环己酮

(356nm)2,6-二(对叠氮基亚苄基)-4-甲基环己酮2,5-双(4-叠氮基-2-磺基亚苄基钠)环戊酮(360nm)4,4′-二叠氮基亚苄基丙酮-2,2′-二磺酸二钠盐According to the present invention, the commonly used disodium salt such as 4,4'-diazide-stilbene-2,2'-disulphonic acid disodium is replaced by a ketone group-containing compound to improve photosensitivity. Examples of keto-substituted compounds useful as the photosensitive component of the photoresist coating include:

(360nm) Disodium 2,2′-(1,5-penta-3-keto-1,4-dienyl)bis(5-azidobenzenesulfonate)

(356nm) 2,6-bis(p-azidobenzylidene)cyclohexanone

(356nm) 2,6-bis(p-azidobenzylidene)-4-methylcyclohexanone 2,5-Bis(4-azido-2-sulfobenzylidene sodium)cyclopentanone (360nm) 4,4′-diazidobenzylideneacetone-2,2′-disulfonic acid disodium salt

The listed compounds are only examples of the improved photosensitive photoresist material according to the present invention, and do not represent all ketone-containing photosensitive compounds used in the photoresist coating layer of the present invention.

The most suitable wavelength for black background optical micro-development technology is 365nm, and the commonly used photosensitive compound 4,4'-diazide transstilbene-2,2'-disodium disulfonate has the maximum light sensitivity at 335nm, Optical microdevelopment to the desired effect is therefore not possible. The present invention utilizes the ketone group (-C=O) in the photosensitive component of the photoresist material to shift the photosensitivity to a longer wavelength. The characteristic wavelength of maximum photosensitivity to incident UV light is listed in parentheses after the photosensitive component of each photoresist material listed above. From the maximum photosensitivity wavelength listed above, it can be known that the photosensitivity of each of the compounds listed above is greater than that of photosensitive compounds in common photoresist materials. In a preferred embodiment, the content of the photosensitive component is 1-30wt% of the weight of the photoresist coating.

When the photoresist coating containing the ketone compound of the present invention is used to prepare the inner surface of the glass display panel of a cathode ray tube, it can be carried out as follows. Firstly, a coating solution comprising polyvinylpyrrolidone (PVP) and water is formed; then polyvinyl alcohol (PVA) is added to the coating solution to improve the adhesion of the coating solution to the glass image display panel; then the present invention is applied The photosensitive disodium salt with ketone group is added in the coating solution; the coating is further hardened, wherein the wavelength of the maximum intensity of the UV light source corresponds substantially to the wavelength of the peak UV photosensitivity of the ketone group-containing compound of the present invention, so it can be Significantly increases the photosensitivity of the coating.

Thus shown is a photoresist coating applied to the inner surface of a cathode ray tube (CRT) glass display panel using optical micrographic techniques in the form of a matrix having a plurality of spaced apart areas, each spaced apart are surrounded by the black photoresist material area. After the photoresist coating is deposited on the glass display panel, the photosensitive photoresist coating is hardened by irradiation with ultraviolet (UV) light having a maximum intensity at a specific wavelength. The photosensitive component of the photoresist coating is selected such that it has maximum photosensitivity at the wavelength of maximum intensity of the UV light, thereby providing a high quality black matrix and improving video image color contrast. The photosensitive component is characterized by containing a ketone group.

While particular embodiments of the invention have been shown and described above, various modifications by those skilled in the art are intended to be embraced within the broad scope of the invention. Accordingly, the appended claims cover all such modifications and modifications as are within the spirit and scope of this invention. What has been described in the foregoing description and accompanying drawings is by way of illustration only and not by way of limitation. The true scope of the invention is defined in the following claims.

Claims (2)

1. improvement photoresistance coating that is used for cathode-ray tube (CRT), it is characterized in that, it comprises polyvinylpyrrolidone PVP, polyvinyl alcohol (PVA) and a kind of photosensitive component with ketone group, this has the ketone group photosensitive component and is selected from 2,2 '-(1,5-five-3-ketone group-1, the 4-dialkylene) two (5-triazobenzene sulfonic acid) disodium, 2,6-two (to the azido benzal) cyclohexanone, 2,6-two (to the azido benzal)-4-methyl cyclohexanone, 2, two (4-azido-2-sulfo group benzal sodium) cyclopentanone of 5-, with 4,4 '-diazido BENZYLIDENE ACETONE-2,2 '-disulfonic acid disodium salt, the content of this photosensitive component is between the 1-30wt% of this photoresistance coating weight.

2. method for preparing the used photoresistance coating of glass image display screen panel inside surface that is used for cathode-ray tube (CRT), this method comprises the following steps:

Formation comprises the coating solution of polyvinylpyrrolidone (PVP) and water:

Polyvinyl alcohol (PVA) (PVA) is added in this coating solution, to improve the adhesion of this coating solution bonding to this glass image display screen panel;

To be selected from 2,2 '-(1,5-five-3-ketone group-1, the 4-dialkylene) two (5-triazobenzene sulfonic acid) disodium, 2,6-two (to the azido benzal) cyclohexanone, 2,6-two (to the azido benzal)-4-methyl cyclohexanone, 2, two (4-azido-2-sulfo group benzal sodium) cyclopentanone of 5-, with 4,4 '-diazido BENZYLIDENE ACETONE-2,2 '-the photosensitivity disodium salt with ketone group of disulfonic acid disodium salt adds in this coating solution;

With light source UV this photoresistance coating that hardens.

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