CN1212980A - Improved stud coating - Google Patents

Abstract

A stud coating that remains flexible and may be baked out in the normal tube baking cycle includes a colloidal graphite suspension in a base that is a solvent for the lacquer film in the aluminized faceplate of the picture tube.

Description

Improved stud coating

The present invention relates to trichromoscope, more particularly, the method that the present invention relates to a kind of improved post applying coatings composition and electric pathway is provided between shadow mask in colour picture tube and panel plate.

The color TV cathode-ray kinescope comprises a glass bulb, and this glass bulb is made up of infundibular body and panel, and panel is sealed on the opening end of infundibular body, and electron beam gun is installed in the neck of infundibular body, so that one or more electron beams to be provided.The internal surface of panel almost is smooth, and accumulation much is subjected to the fluorescent substance of electron-beam excitation on it.By covering fluorescent substance, it can only be activated by an electron beam, thereby utilize shadow mask to select color.With a plurality of suspension springs shadow mask accurately is fixed on the panel, stretches out metal column from panel, above-mentioned suspension spring joins on the metal column separably.Be coated on the internal surface of infundibular body as electrically conducting coating with deflocculated graphite, and supply with high-voltage by the anode button on the funnel body wall.

But on window of tube, apply one deck electron-osmosis aluminium film usually and make the window of tube calorize.This aluminium film plays the effect of mirror, increases the briliancy of demonstration by reflection by the light backward that fluorescent substance produces.Before aluminium coat, coating one deck organic materials film, for example lacquer on phosphor layer.Organic membrane has been filled irregular zone on the phosphor layer, but and formed the smooth surface of a deposit aluminium film, the aluminium film of institute's deposit has the smooth property of lacquer.

Anode voltage on the infundibular body coating must be added on the shadow mask and the aluminium film on.Its electric pathway comprises one or more springs, and these springs stretch out and engage with the infundibular body coating from shadow mask.The shadow mask anode potential imports on the aluminium film by shadow mask suspension spring and metal mainstay.For the perfect electric pathway that leads to the aluminium film, coated conductors on metal mainstay " moustache ", it reaches the aluminium film.The material that comprises the conductor moustache is considered to stud coating usually.

In the prior art, the conductor material that was widely used as anti-coating material in the past comprises a kind of water-soluble silicate that is fit to the brush coating.In follow-up pipe roasting procedure, dewater, between post and aluminium film, stay hard conducting film.Usually contain potassium silicate in the alkaline aqueous solution or water glass is made tackiness agent, and can always not keep " moistening ", also do not adhere on the parts.Thereby, from post and on the glassy zone, usually can fall down the coating fragment, these fragments can be blocked the one or more fenestras on the shadow mask, and this usually can cause pipe defective.These particles can cause also that in the electron beam gun zone internal electrode produces electric arc and/or damages negative electrode.Before the graphitization powder, aqueous solution overlay need carry out extra roasting procedure after calorize and on the post.

The application people is that the United States Patent (USP) 4289800 and 4301041 of peak electronics corporation (Zenith Electronics Corporation) has solved the problems of the prior art recited above, and cancelled calorize extra baking procedure afterwards in process of production, thereby obviously reduced cost.Two pieces of patent documentations of institute's reference here disclose a kind of method and a kind of post coating composition, this post coating composition comprises a kind of mixture of being made up of glass fusion particle and gluey graphite, wherein contain the volatilizable solvent and the thickening material that can dissolve paint film (below the aluminium film), so that make its viscosity reach the degree that can apply.Solvent passes porous aluminium film, infiltrates in the enamelled coating, and excludes when pipe being carried out toast in the stove.Disclosed method of these patent documentations and post applying soln are widely used in industrial circle, and have used the several years.

Glass fusion type post coating described in the above-mentioned patent documentation will produce defective when production process breaks down or interrupt.Especially when pipe is subjected to high-temperature time long in stove, will go wrong, for example when production line stops, will going wrong.Plumbous oxide in the glass rafting and the reaction of the carbon in the graphite generate carbonic acid gas and lead, thereby reduce the electroconductibility of stud coating.In many cases, the baker of production line standstill period is added thermal control can avoid this problem,, but still have some difficulties although also can control to long-time pause.A large amount of stud coatings intactly remains and makes the pipe can be by final check and test, but so also can bring problem, and it can cause often producing electric arc, and in use finally causes fault.Though problem is countless, because problem does not come out when teletron is carried out routine test, thereby this is a kind of disaster to teletron, obviously is a kind of economical load and trouble concerning the human consumer.

Main purpose of the present invention is to improve the working reliability of color cathode ray tube.

Another object of the present invention is to reduce the manufacturing cost of color cathode ray tube.

A further object of the present invention is to improve a kind of cathode tube, and it makes the arc drop that causes because of the post coating to minimum.

As previously mentioned, have the developing panel of a band fluorescent substance on the color cathode ray tube, be coated with paint film and aluminium film on this panel successively.With a plurality of metal columns that stretch out from panel shadow mask is fixed on the panel then.Between shadow mask and aluminium film, form the electrical connection bridge, thereby make aluminium film holding anode current potential by post and post coating.(well-known, carry out sealing-in with nonconducting glass alloying material between teletron panel and the infundibular body, spring passes alloying material, utilizes these springs that the intravital coating of shadow mask and funnel is electrically connected, thereby makes shadow mask have anode voltage.)

According to the present invention, be used for forming the mixture that hard modified version solution mainly comprises a kind of graphite granule that dries by the fire that the post coating is electrically connected bridge or moustache, this particulate size is in the scope of micron order (micro-sized).These particles are in suspension, and this suspension contains a kind of volatile solvent that can dissolve paint film.Also comprise a kind of thickening material in the suspension, its add-on is enough to make the viscosity of suspension to reach the degree that can apply with brush.Because applied solution between post and the aluminium film suspending, therefore, this solution can infiltrate in the paint film, when pipe was toasted, solution hardening formed nonvolatil electrical conductor cross structure between shadow mask and aluminium film.

The viscosity of described solution is preferably about 550 centipoises in the scope of 200-800 centipoise (centripoise).After baking, the resistance of solution is in the scope of 100-500 Ω.Conductor pin coating material of the present invention can mix (preparing one gallon) as follows.The equivalent material that can provide with other supplier.

225 gram acrylic resins (Elvacite 2044-Source ICI Acrylics) are dissolved in the pure ethylene glycol butyl ether (E179 of Fisher Scientific company) as acrylic resin standby (stock) solution.

Weigh up 225 gram ethylene glycol butyl ethers with suitable containers (2000 ml beaker), with 675 gram N-butylacetate (N-butyl acetate, the B-396 of Fisher Scientific company) and 630 the gram resin glues be added to wherein, and stir, even until solution, thus adhesive resin solution made.

Following material is added in the ball mill nearly 8000 gram ball-milling mediums in this ball mill:

Composition	Quantity (gram)	% (weight)	Scope
				Graphite HPN-2	????630	????14	?36144
Graphite LN1052 (Source Grapfo Colloids)	????90	????2	?35797
				The acrylic resin stock solution	????2250	????50	?45-50
Adhesive resin solution	????1530	????34	?30-38

Ball grinder was rotated 22-24 hour, the coating suspension behind the ball milling is poured in 1 gallon the container.

The preparation of this coating material should be carried out in the good environment of ventilation condition, and will take certain safeguard procedures, and for example the relevant personnel are with Rubber gloves, are with mouth mask, wear the laboratory protective coat, hairnet and putting on shoe covers etc.Because N-butylacetate and resin binder solution are inflammable substance, so also must be careful.

Stud coating prepared according to the present invention and that use has been avoided above-mentioned problem because of using glass fusion type stud coating to cause.The principal feature of this new stud coating is that it has toughness (handling the back), makes it strengthen peeling resistance.In addition, stud coating cost of the present invention is low, and has and do not need advantage that teletron is additionally toasted.

In when test, be coated to the fusion type stud coating of prior art on the post and the aluminium film on, and with 450 ℃ temperature heating 2 hours, then the resistance of coating rose to 73000 Ω from 300 Ω.And with new stud coating, under same condition, its resistance then remains 300 Ω.

In the production line operational process of chromoscope, the substandard products that occur because of post electric arc during with the fusion type stud coating of prior art account for 0.3%, and during with stud coating of the present invention, the substandard products of post electric arc aspect then do not occur.

Foregoing novel post coating composition and method have solved the be electrically connected problem of chromoscope center pillar with the aluminium film.Clearly, concerning those of ordinary skill, can make multiple improvement to example of the present invention, and can not deviate from spirit of the present invention, also can not exceed scope of the present invention.Scope of the present invention is only determined by appended claims.

Claims (9)

1. method of making post coating comprises:

A kind of deflocculated graphite mixture is provided;

Preparation acroleic acid resin solution, it can infiltrate in the paint film of the teletron panel of calorize;

Preparation resin binder solution; And

Described solution and described graphite mixture are ground together.

2. method according to claim 1 wherein is dissolved into acroleic acid resin and prepares acroleic acid resin solution in the ethylene glycol butyl ether.

3. method according to claim 2 wherein, mixes ethylene glycol butyl ether, N-butylacetate and resin tackiness agent with preparation resin binder solution.

4. method according to claim 3, wherein, the weight percent of each composition is approximately in the post coating solution:

16% deflocculated graphite;

14% resin (tackiness agent);

5% acroleic acid resin;

The 15%N-butylacetate; And

50% ethylene glycol butyl ether.

5. stud coating is used for panel of color picture tube and realizes being electrically connected between post and the aluminium film, comprising:

Be dispersed in the deflocculated graphite in the acroleic acid resin solution, described acroleic acid resin solution can infiltrate in the enamelled coating below the described aluminium film;

Solvent in the described coating material is carrying out being dried with described enamelled coating in the bake process to pipe, and described conductive connection part divides maintenance toughness, antistripping.

6. coating material according to claim 5, wherein, described coating material comprises:

A kind of acroleic acid resin solution; And

A kind of resin binder solution.

7. coating material according to claim 6, wherein, described acroleic acid resin solution comprises a kind of acroleic acid resin that is dissolved in the ethylene glycol butyl ether.

8. coating material according to claim 7, wherein, described resin binder solution comprises resin tackiness agent, N-butylacetate and ethylene glycol butyl ether.

9. coating material according to claim 8, wherein, the weight percent of each composition is approximately in the described coating material:

16% deflocculated graphite;

14% resin (tackiness agent);

5% acrylic resin;

The 15%N-butylacetate; And

50% ethylene glycol butyl ether.