CN1367211A - Graphite conducting coating material - Google Patents

Abstract

The composition of a graphite conducting coating contains (wt%) graphite 3-10%, dispersing agent 0.1-3.0%, adhesive 3-18% ammonia water 0.1-10% and pure water 60-90%, in which the described dispersing agent is at least one kind of carboxymethyl cellulose, hydroxyethyl cellulose, acacia, silicon oil, polyacrylate, sodium dodecyl sulfonate or sodium lignosulfonate, and the ddscribed adhesive is at least one kind of colloidal silicon dioxide, colloidal aluminium oxide, water glass or pure acrylic emulsion. The invented coating possesses regular strips, good contrast, its coat film is uniform on drying, smooth and level, and has no peeling.

Description

A kind of graphite conducting coating material

Affiliated technical field

The present invention relates to a kind of electrically conducting coating that is used for chromoscope.

Background technology

At present, mainly there is following defective in the used for color picture tube electrically conducting coating: 1, striped is irregular after the film forming, make pore-creating after grid uneven, have a strong impact on the image stabilization and the reception of chromoscope.2, contrast gradient is the important indicator that influences chromoscope, mainly be meant the black and white contrast degree of colored picture tube, and existing electrically conducting coating is difficult to satisfy the index request of contrast gradient.3, more " blue dirty " phenomenon, this phenomenon mainly is reflected on the color of image, mainly is that copper content " blue dirty " occur probably more than 50ppm usually due to this electrically conducting coating copper content overproof.4, " black muscle " phenomenon, the slight change (as shielding variations such as temperature, development pressure) that can not adapt to coated technique owing to this kind electrically conducting coating causes, and forms the tiny ripple of a rule in filming, and black muscle is generally along with film takes place.5, dried coating film is inhomogeneous, causes graphite to come off easily, and blocks shadow cover hole.How overcoming above-mentioned defective as early as possible, then is people's urgent problem.

Summary of the invention

The present invention be to solve that the striped that prior art exists is irregular, technical problems such as poor contrast, appearance " blue dirty " and " deceiving muscle " phenomenon.

In order to reach the purpose that solves the problems of the technologies described above, technical scheme of the present invention is that a kind of graphite conducting coating material is characterized in that: make (weight percent) by following component and proportioning:

Graphite 3～10%;

Dispersion agent 0.1～3.0%;

Caking agent 3～18%;

Ammoniacal liquor 0.1～10%;

Pure water 60～90%;

Wherein said dispersion agent is at least a in carboxymethyl cellulose, hydroxyl hexyl Mierocrystalline cellulose, gum arabic, silicone oil, polyacrylate, sodium laurylsulfonate or the sodium lignosulfonate;

Described caking agent is at least a in colloid silica, colloidal alumina, water glass or the pure-acrylic emulsion.

Described graphite particle diameter will be all less than 1 μ m, wherein less than the graphite particle content of 0.1 μ m 53～59%, should be less than the graphite particle content of 0.5 μ m 75～98%.

Electrically conducting coating of the present invention has solved the existing in prior technology problem, makes its performance reach good, has improved the overall performance electrical performance of chromoscope.

Various performance perameter of the present invention detects in order to following method:

1, solid content: the electrically conducting coating for preparing is coated on the glass coating uniformly, the record amount of being coated with, drying is about 1.5 hours in 105～110 ℃ of loft drier, moves in the moisture eliminator and cools off, and notes the weight of filming again, and the ratio of front and back value is a solid content.

2, pH value: behind the electrically conducting coating mixing, get 50ml and place beaker, get final product by PH using method mensuration.

3, pore-forming character: the photoresists organic membrane test piece of making is placed under the porous plate, behind ultraviolet exposure, fall unexposed organic membrane with warm water soaking, soak electrically conducting coating liquid again, soak with etching liquid then, organic membrane is etched away together with the equadag coating on the film, the bar shaped aperture of formation rule, examine under a microscope, test piece pore-creating shape and sample pore-creating figure are compared, judge whether pore-creating is qualified.

4, surmise: utilize sedimentograph to measure by its operation steps.

5, iron level is measured: get electrically conducting coating 3～5 grams, add 50% hydrochloric acid 20ml heating 30 minutes.Filtration washing and fully ashing placed the crucible calcination 30～40 minutes, and cooling adds 3ml hydrochloric acid to pasty state, add 10ml 2% hydrochloric acid again, heating and filtering and original solution merge, and it is standby to be diluted to 50ml with pure water, gets this solution 5ml as in the beaker, be diluted to 50ml with pure water, add 6～8 sulfosalicylic acid sodium salt indicator, adjust pH value to 1.5～2.0 and be heated to 70 ℃, with the titration of 0.005m disodium ethylene diamine tetraacetate reference liquid, become yellow by purple, iron level is calculated as follows:

Fe (ppm)=(TFev/m) * 100% TFe: the disodium ethylene diamine tetraacetate standardized solution is to the titre mg/ml of iron.V: consume disodium ethylene diamine tetraacetate standard volume ml during titration.M: sample mass mg.

6, viscosity: under 25 ℃ of conditions, measure with No. 1 rotor.

Below just material therefor of the present invention and ratio range thereof be explained as follows:

1, graphite

Select graphite particle for use, when consumption is lower than 3%, occurs thin printing opacity of film and black muscle phenomenon easily, and conduct electricity bad through special processing.And with being higher than at 10% o'clock, under the effect of several kilograms of development pressure, easily the flushing of graphite striped is come off.In addition, in order to have good pore-creating effect, the graphite particle diameter will be all less than 1 μ m, wherein less than the graphite particle content of 0.1 μ m 53～59%, should be less than the graphite particle content of 0.5 μ m 75～98%.

2, dispersion agent

The selected dispersion agent of the present invention can use separately, also can two or more be used, to reach good dispersion effect.Consumption is lower than at 0.1% o'clock, disperses inhomogeneously, and consumption is higher than at 3.0% o'clock, influences film-formation result.

3, caking agent

When consumption was lower than 3%, adhesion strength was not enough, and filming is rinsed out by water easily, and consumption is higher than at 18% o'clock, and bonding force is excessive, and when being coated with the screen operation, graphite is difficult to be etched.

4, ammoniacal liquor

Selecting ammoniacal liquor is in order to adjust the pH value of electrically conducting coating, because of graphite particle very thin, through evidence, pH value disperseed best results at 9～11 o'clock, and when consumption was lower than 0.1%, pH value did not reach 9～11, when consumption is higher than 10%, pH value exceeds 9～11 scopes, is strong alkali environment, easily colored picture tube and material is caused corrosion.

5, pure water

As the water that disperses medium must be to handle through strict, otherwise will influence electroconductibility.Viscosity is too high when consumption is lower than 60%, and difficulty during the coating operation is difficult to form smooth slick filming, and when consumption was higher than 90%, viscosity was low excessively, trickled easily during coating, forms the thin and printing opacity of film.

Description of drawings

Fig. 1 is the chromoscope structural map.

1, vitreum; 2, display screen; 3, cone central part; 4, neck; 5, select electrode; 6, pin position; 7, electron beam gun; 8,9,10, electron beam; 11, deflector coil; 12, fluor shadow mask; 13, inner conductive film layer; 14, outer conductive film layer; 15, electrically conducting coating layer.

Electrically conducting coating of the present invention is coated on the inwall of display screen 2 among the figure, and promptly the electrically conducting coating layer 15, forms a common electric capacity with inside and outside conductive film layer 13,14, reaches the required electrical specification of chromoscope.

Embodiment

Embodiment 1, (the graphite particle diameter will be all less than 1 μ m for graphite 7%, wherein less than the graphite particle content of 0.1 μ m 53～59%, should be less than the graphite particle content of 0.5 μ m 75～98%), sodium polyacrylate 0.5%, colloid silica 16%, ammoniacal liquor 0.8%, pure water balance to 100%.The electrically conducting coating layer of present embodiment records following result through the aforementioned method of inspection: solid content: viscosity 10.2%: 21CP (25 ℃) pH value: 10.2, pore-forming character: qualified, Fe:1550PPm, granularity:＜0.1 μ m 56.2%,＜1.0 μ m100%.

Embodiment 2, graphite 9% (the graphite material footpath is with embodiment 1), gum arabic 1.5%, colloidal alumina 8%, ammoniacal liquor 1%, pure water balance to 100%.The electrically conducting coating layer of present embodiment records following result through the aforementioned method of inspection: solid content: viscosity 10.5%: 26CP (25 ℃) pH value: 10.4, pore-forming character: qualified, Fe:1610PPm, granularity:＜0.1 μ m 56.1%,＜1.0 μ m100%.

Embodiment 3, graphite 3.5% (the graphite material footpath is with embodiment 1), sodium lignosulfonate 2.7%, water glass 16%, ammoniacal liquor 7%, pure water balance to 100%.The electrically conducting coating layer of present embodiment records following result through the aforementioned method of inspection: solid content: viscosity 9.9%: 22CP (25 ℃) pH value: 10.6, pore-forming character: qualified, Fe:1496PPm, granularity:＜0.1 μ m 56.8%,＜1.0 μ m100%.

Component thorough mixing with the foregoing description stirs, and adds dispergation dispersion in the ball mill, and behind the discharge, detection, adjustment, deironing, screening get final product.

The present invention is through examination, and draw following result: striped is neat, and contrast gradient is good, does not have " blue dirty " and reaches " black muscle " phenomenon, and dried coating film is even, and smooth smooth, nothing comes off.

Claims (2)

1, a kind of graphite conducting coating material is characterized in that: make (weight percent) by following component and proportioning:

Graphite 3～10%;

Dispersion agent 0.1～3.0%;

Caking agent 3～18%;

Ammoniacal liquor 0.1～10%;

Pure water 60～90%;

Wherein said dispersion agent is at least a in the basic Mierocrystalline cellulose of carboxymethyl cellulose, hydroxyl, gum arabic, silicone oil, polyacrylate, sodium laurylsulfonate or the sodium lignosulfonate;

Described caking agent is at least a in colloid silica, colloidal alumina, water glass or the pure-acrylic emulsion.

2, graphite conducting coating material according to claim 1 is characterized in that: described graphite particle diameter will be all less than 1 μ m, less than the graphite particle content of 0.1 μ m 53～59%, should be less than the graphite particle content of 0.5 μ m 75～98%.

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