CN108129939B - Durable coating for developing roller and preparation method thereof - Google Patents

Abstract

The invention discloses a durable coating for a developing roller and a preparation method thereof. The technical solution includes the following components in parts by weight: 70-90 parts of fluorine-containing macromolecular polymer, 1 part of polytetrafluoroethylene powder ~10 parts, 2-20 parts of fluorinated graphite powder, 1-10 parts of carbon black, 3-20 parts of curing agent, 1-2 parts of antistatic agent, 0.1-1 part of catalyst, the coating has a high melting point, It is not easy to fuse on the surface of the developing roller; the lubrication performance is good, and the friction between the powder knife and the surface of the developing roller can be adjusted; at the same time, it has the sustainable release of toner, which helps to ensure that the toner is in the whole process. Good transportability over the print life cycle, resulting in high-quality printed images.

Description

A kind of durable coating for developing roller and preparation method thereof

technical field

The present invention relates to a coating of a developing roller and its preparation, in particular to a durable coating for a developing roller and a preparation method thereof.

Background technique

Generally speaking, the printing and copying in the laser or LED printing device is carried out in this way, after the photosensitive drum is charged and scanned and exposed, an electrostatic latent image of the document is formed on the surface of the photosensitive drum, and a developing bias is applied to the developing roller. Then, the toner is attached to the electrostatic latent image to form a toner image, which is transferred and fixed to obtain a printed document on paper. The process of developing between the developing roller and the photosensitive drum is as follows, that is, the toner in the powder bin is supplied to the surface of the developing roller by the toner feed roller, and the surface of the developing roller is rubbed with the toner knife to form a certain thickness of toner. The toner layer is charged, and the toner layer is formed by adhering to the electrostatic latent image of the photosensitive drum after applying a developing bias.

Due to the important role of the developing roller in the printing process, a performance requirement for the developing roller is that the developing roller has good toner conveying performance, and requires that the toner conveying performance remains unchanged during the entire printing life cycle, so as to obtain For high-quality printed and copied documents, toner is usually mixed with resin, pigment, charge control agent, fumed silica, low molecular weight polyethylene or polypropylene wax. The friction of the powder knife, when the friction is large, the toner is easy to adhere to the surface of the developing roller. Because the toner contains low-molecular-weight wax and other low-melting substances, such as the friction is large, and with the continuous increase of the number of printed documents, it is easy to cause The low-molecular-weight substances of the toner are fused on the surface of the developing roller, which leads to the continuous deterioration of the printing quality, and high-quality printed images cannot be obtained.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a durable coating for the developing roller, which can adjust the friction force of the carbon powder between the powder discharge knife and the surface of the developing roller, and can ensure that the low-molecular-weight wax in the carbon powder composition will not The surface of the developing roller is fused, and the toner has good transportability throughout the printing life cycle, resulting in high-quality printed images.

The above-mentioned technical purpose of the present invention is achieved through the following technical solutions:

A durable coating for a developing roller, comprising the following components by weight: 70-90 parts of fluorine-containing macromolecular polymer, 1-10 parts of polytetrafluoroethylene powder, 2-20 parts of fluorinated graphite powder, 1~10 parts of carbon black, 2~10 parts of curing agent, 1~2 parts of antistatic agent, 0.1~1 part of catalyst.

By adopting the above technical solutions, the fluorine-containing polymer has a unique structure, so it exhibits special properties. Because the fluorine atom has low polarizability, strong electronegativity, small van der Waals radius, strong C-F bond energy, so the fluorine-containing polymer has high heat resistance, chemical resistance, durability and weather resistance, non-stick, low friction, waterproof, high insulation;

PTFE powder has excellent smoothness in coatings and printing inks, which can enable the coating to obtain a very small sliding friction coefficient and have excellent wear resistance; PTFE powder is not easily dissolved by any solvent, It will not dissolve even at high temperature, and has the excellent effect of smoothness and wear resistance; PTFE powder has good dispersibility, and can be directly added into the system for stirring and grinding;

The interlayer structure of fluorinated graphite powder is very small, which has excellent lubricating properties; the surface energy is extremely low, and it has good waterproof and oleophobic properties; at the same time, the friction coefficient is small, and it has good lubricating properties, electrochemical properties, and chemical properties;

In the present invention, fluorine-containing macromolecular polymer, polytetrafluoroethylene powder, fluorinated graphite powder and carbon black are mixed to prepare a durable coating. Sintered; good lubricating performance, can adjust the friction between the powder knife and the surface of the developing roller; at the same time, it has the sustainable release of toner, which helps to ensure the toner has a good delivery throughout the printing life cycle to obtain high-quality printed images.

The present invention further provides that: the fluorine-containing high molecular polymer comprises at least one of fluorine-containing acrylic resin, fluorosilicon copolymer resin, and fluorocarbon resin.

By adopting the above technical solution, the fluorine-containing acrylic resin not only has the characteristics of light color, high transparency, good film-forming property, good color and gloss retention, tough coating film and strong adhesion of acrylic resin, but also has the surface of organic fluorine resin. Low energy, excellent hydrophobicity and oleophobicity, good solvent resistance and chemical stability; Fluorosilicone copolymer resin has low surface energy, excellent weather resistance, high and low temperature resistance, water resistance, oil resistance, UV resistance and antistatic Dust absorption; Fluorocarbon resin takes firm C-F as the skeleton and has excellent heat resistance, chemical resistance, cold resistance, low temperature flexibility, weather resistance and electrical properties, etc. Due to its good crystallinity, It is non-adhesive and non-wetting.

The present invention is further provided that: the surface free energy of the fluorine-containing high molecular polymer is 10-30 mJ/m ² .

By adopting the above technical solution, due to the wide variation range of the molecular weight of the polymer, the surface free energy of the fluorine-containing polymer with different molecular weights is different. Controlling the surface free energy of the fluorine-containing polymer to be lower is helpful to To ensure that the fluoropolymer has excellent non-stick properties.

The present invention is further provided that: the average particle size of the polytetrafluoroethylene powder is 5-10 μm.

By adopting the above technical solution, the particle size of PTFE powder is micron, the average particle size is small, it has good dispersibility, it is easy to be blended with other fillers, and it has excellent heat resistance, weather resistance and cold resistance. , Low friction, non-stick, chemical stability, electrical insulation and other properties; can also be used as a lubricant.

The present invention further provides that: the fluorinated graphite powder can be replaced by a carbon nanotube dispersion or a graphene dispersion.

By adopting the above technical solutions, carbon nanotubes have unique electrical conductivity, high thermal stability and intrinsic mobility, large specific surface area, and micropores are concentrated in a certain range; at the same time, carbon nanotubes have extremely high strength, and Extremely high toughness; carbon nanotube dispersion has both the electrical conductivity, thermal stability, high strength and high toughness of carbon nanotubes, and also has excellent dispersibility; graphene is one of the highest strength materials, and also It has good toughness and can be bent; graphene has a large carrier mobility at room temperature, which is 10 times higher than that of silicon materials, and has good thermal stability, high strength and high toughness; The graphene dispersion also has excellent electrical conductivity, thermal stability, high strength, high toughness and good dispersion properties.

The present invention is further configured as follows: the carbon nanotube dispersion liquid contains 1~5% of carbon nanotubes, 0.1~1.0% of dispersant, 0.2~0.5% of wetting agent, 0.5~1.0% of water-based defoamer, anti-settling agent 0.2~1.0% of the chemical agent, 0.1~1.0% of 25% chemically pure ammonia water, and the balance is deionized water.

By adopting the above technical scheme, the carbon nanotube dispersion liquid is mixed with the above components, and the prepared dispersion liquid has the advantages of good dispersibility and uniform mixing.

The present invention further provides that: the curing agent includes at least one of amino resin curing agent, aliphatic polyisocyanate cross-linking agent, isocyanate-containing silane coupling agent, and aziridine cross-linking agent.

By adopting the above technical scheme, adding at least one of amino resin curing agent, aliphatic polyisocyanate crosslinking agent, isocyanate-containing silane coupling agent, and aziridine crosslinking agent into the system, the fluorine-containing high in the system The components of molecular polymer, polytetrafluoroethylene powder, and fluorinated graphite powder are cross-linked to prepare a durable coating with excellent electrical conductivity, non-stickiness, and improved sustainable release of carbon powder.

Another object of the present invention is to disclose a preparation method of a durable coating for a developing roller, comprising the following steps:

(1) Ingredients: Weigh 70-90 parts of fluorine-containing polymer, 1-10 parts of PTFE powder, 2-20 parts of fluorinated graphite powder, 1-10 parts of carbon black, and 2-10 parts of curing agent , 1~2 parts of antistatic agent, 0.1~1 part of catalyst;

(2) Put the fluorine-containing polymer, polytetrafluoroethylene powder, fluorinated graphite powder, carbon black, and antistatic agent into the mixer in turn, and stir them thoroughly. The stirring time is 2~2.5h;

(3) Add curing agent and catalyst to the mixture in step (2), and stir for 5-15 minutes.

By adopting the above technical scheme, the preparation process involves mixing, stirring and cross-linking, and has the advantages of simple operation and excellent product performance.

To sum up, the present invention has the following beneficial effects:

The invention provides a durable coating with good carbon powder releasability and a preparation method thereof. The coating has a high melting point and is not easy to be sintered on the surface of the developing roller; The friction between the surface of the developing roller and the surface of the developing roller can be adjusted; at the same time, it has the sustainable release of toner, which helps to ensure that the toner has good transportability throughout the printing life cycle and obtains high-quality printed images.

Detailed ways

The present invention will be described in further detail below in conjunction with the embodiments.

Preparation work: Preparation of carbon nanotube dispersion liquid: The carbon nanotube dispersion liquid with a solid content of 3% is an aqueous slurry obtained by dispersing carbon nanotubes, water and various dispersing aids; Vinyl alcohol 0.5%, dodecylphenol polyoxyethylene ether 0.3%, organosilicon compound 0.5%, anti-settling agent 0.3%, 25% chemically pure ammonia water 0.5%, and the balance is deionized water.

Example 1:

A preparation method of a durable coating for a developing roller, comprising the steps of:

(1) Ingredients: Weigh 70 parts of fluorine-containing acrylic resin, 1 part of polytetrafluoroethylene powder, 2 parts of fluorinated graphite powder, 1 part of carbon black, 3 parts of aliphatic polyisocyanate crosslinking agent, dodecyl sulfonic acid 1 part of sodium, 0.1 part of catalyst;

(2) Put fluorine-containing acrylic resin, polytetrafluoroethylene powder, fluorinated graphite powder, carbon black, and sodium dodecyl sulfonate into the ball mill in turn, and grind them thoroughly, and the stirring time is 2h;

(3) After stirring, continue to put in the aliphatic polyisocyanate crosslinking agent and catalyst, and stir for 10 minutes.

Embodiment 2:

A preparation method of a durable coating for a developing roller, comprising the steps of:

(1) Ingredients: Weigh 75 parts of fluorine-containing acrylic resin, 3 parts of polytetrafluoroethylene powder, 5 parts of fluorinated graphite powder, 3 parts of carbon black, 3 parts of aliphatic polyisocyanate crosslinking agent, dodecyl sulfonic acid 1 part of sodium, 0.1 part of catalyst;

(2) Put the fluorine-containing acrylic resin, polytetrafluoroethylene powder, carbon nanotube dispersion, carbon black, and sodium dodecyl sulfonate into the ball mill in turn, and grind them fully, and the stirring time is 2h;

(3) After stirring, continue to put in the aliphatic polyisocyanate crosslinking agent and catalyst, and stir for 10 minutes.

Embodiment three:

A preparation method of a durable coating for a developing roller, comprising the steps of:

(1) Ingredients: Weigh 80 parts of fluorine-containing acrylic resin, 5 parts of polytetrafluoroethylene powder, 5 parts of fluorinated graphite powder, 5 parts of carbon black, 5 parts of aliphatic polyisocyanate crosslinking agent, dodecyl sulfonic acid 1 part of sodium, 0.3 part of catalyst;

(2) Put the fluorine-containing acrylic resin, polytetrafluoroethylene powder, carbon nanotube dispersion, carbon black, and sodium dodecyl sulfonate into the ball mill in turn, and grind them fully, and the stirring time is 2h;

(3) After stirring, continue to put in the aliphatic polyisocyanate crosslinking agent and catalyst, and stir for 10 minutes.

Embodiment 4:

A preparation method of a durable coating for a developing roller, comprising the steps of:

(1) Ingredients: Weigh 85 parts of fluorine-containing acrylic resin, 8 parts of polytetrafluoroethylene powder, 10 parts of fluorinated graphite powder, 7 parts of carbon black, 8 parts of aliphatic polyisocyanate crosslinking agent, dodecyl sulfonic acid 2 parts of sodium, 0.5 part of catalyst;

(2) Put fluorine-containing acrylic resin, polytetrafluoroethylene powder, fluorinated graphite powder, carbon black, and sodium dodecyl sulfonate into the ball mill in turn, and grind them thoroughly, and the stirring time is 2h;

(3) After stirring, continue to put in the aliphatic polyisocyanate crosslinking agent and catalyst, and stir for 10 minutes.

Embodiment 5:

A preparation method of a durable coating for a developing roller, comprising the steps of:

(1) Ingredients: Weigh 90 parts of fluorine-containing acrylic resin, 10 parts of polytetrafluoroethylene powder, 15 parts of fluorinated graphite powder, 10 parts of carbon black, 3 parts of aliphatic polyisocyanate crosslinking agent, dodecyl sulfonic acid 2 parts of sodium, 1 part of catalyst;

(2) Put fluorine-containing acrylic resin, polytetrafluoroethylene powder, fluorinated graphite powder, carbon black, and sodium dodecyl sulfonate into the ball mill in turn, and grind them thoroughly, and the stirring time is 2h;

(3) After stirring, continue to put in the aliphatic polyisocyanate crosslinking agent and catalyst, and stir for 10 minutes.

Comparative example: The HPCP1025 developing roller was purchased in the flagship store of Taobao store for testing.

Detection method: spray the durable coating of this example on the surface of the ordinary developing roller to prepare samples; print each sample and the developing roller of the comparative example respectively, to ensure that the specifications and materials of the printing paper are the same, and 100 pages, At 150 pages and 200 pages, observe the apparent quality of pages 100, 150 and 200.

sample 100 pages 150 pages 200 pages sample one Legible Legible Legible Sample two Legible Legible Legible Sample three Legible Legible Legible Sample four Legible Legible Legible Sample five Legible Legible Legible Comparative ratio Legible Fuzzy writing and ghosting incomplete handwriting

It can be seen from the above table that the developing rollers of each sample maintained a relatively long-lasting toner release, and after printing 100, 150 and 200 pages of paper, the writing on the paper could still be kept clear; while the developing rollers on the market were used, When printing about 150 sheets, there will be blurred handwriting and ghosting.

This specific embodiment is only an explanation of the present invention, and it does not limit the present invention. Those skilled in the art can make modifications without creative contribution to the present embodiment as required after reading this specification, but as long as the rights of the present invention are used All claims are protected by patent law.

Claims (4)

1. A durable coating for a developing roller, characterized in that it comprises the following components in parts by weight: 70-90 parts of fluorine-containing macromolecular polymers, 1-10 parts of polytetrafluoroethylene powder, 2 parts of fluorinated graphite powder ~20 parts, 1~10 parts carbon black, 2~10 parts aliphatic polyisocyanate crosslinking agent, 1~2 parts sodium dodecyl sulfonate, 0.1~1 part catalyst; The fluorine-containing polymer is selected from fluorine-containing acrylic resin; the surface free energy of the fluorine-containing polymer is 10-30 mJ/m ² ; The average particle size of the polytetrafluoroethylene powder is 5-10 μm. 2 . The durable coating for a developing roller according to claim 1 , wherein the fluorinated graphite powder can be replaced by a carbon nanotube dispersion or a graphene dispersion. 3 . 3. A kind of durable coating for developing roller according to claim 2, it is characterized in that: described carbon nanotube dispersion liquid contains 1～5% of carbon nanotubes, 0.1～1.0% of dispersant, wetting 0.2~0.5% of the antifoaming agent, 0.5~1.0% of water-based defoamer, 0.2~1.0% of anti-settling agent, 0.1~1.0% of 25% chemically pure ammonia water, and the balance is deionized water. 4. a kind of preparation method for the durable coating of developing roller as claimed in claim 1 is characterized in that comprising the steps: (1) Ingredients: Weigh 70-90 parts of fluorine-containing polymer, 1-10 parts of PTFE powder, 2-20 parts of fluorinated graphite powder, 1-10 parts of carbon black, and 2-10 parts of curing agent , 1~2 parts of antistatic agent, 0.1~1 part of catalyst; (2) Put the fluorine-containing polymer, polytetrafluoroethylene powder, fluorinated graphite powder, carbon black, and antistatic agent into the mixer in turn, and stir them thoroughly. The stirring time is 2~2.5h; (3) Add curing agent and catalyst to the mixture in step (2), and stir for 5-15 minutes.