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CN-122011867-A - Ionomer coatings for eliminating surface charge, method for preparing same and corresponding coatings

CN122011867ACN 122011867 ACN122011867 ACN 122011867ACN-122011867-A

Abstract

The invention relates to an ionomer coating for eliminating surface charges, which comprises a main resin, an acidic ionomer, a main crosslinking agent, a polar solvent, an auxiliary crosslinking agent and a polar solvent, wherein the main crosslinking agent has hydrogen bond groups and base groups, the functionality of the base groups is 1, the functionality of the hydrogen bond groups is more than or equal to 1, and epoxy resin can be added as the auxiliary crosslinking agent, and the functionality of the epoxy resin is more than or equal to 2. The invention also provides a preparation method and a coating of the corresponding ionomer coating. The ionomer coating for eliminating surface charges, the preparation method and the corresponding coating have the advantages that the service life of the ionomer coating can be greatly prolonged on the premise of not influencing the storage life and the coating performance of the acid ionomer coating, the coating can be cured at a low temperature to form a film, is suitable for a thermolabile plastic substrate, can be prepared into a water-based coating, reduces pollution, has low cost of raw materials, is convenient to implement, and is suitable for large-scale industrial application.

Inventors

  • XU NING

Assignees

  • 徐宁

Dates

Publication Date
20260512
Application Date
20201228

Claims (7)

  1. 1. An ionomer coating for eliminating surface charges comprising the following components: A main body resin; An acidic ionomer; The main crosslinking agent is provided with a hydrogen bond group and a base group, the functionality of the base group is 1, the functionality of the hydrogen bond group is more than or equal to 1, the main crosslinking agent is octyl triazinone, and the molar ratio of the monofunctional base group in the crosslinking agent with the hydrogen bond group and the base group to the acidic group in the acidic ionomer is 0.05-1; A polar solvent; The coating can be dried in solvent at a temperature below 85 ℃ to form the coating for eliminating surface charges.
  2. 2. The ionomer coating for surface charge removal as claimed in claim 1, wherein said acidic ionomer is an acidic ionomer partially neutralized with basic groups.
  3. 3. The ionomer coating for eliminating surface charges as claimed in claim 2, wherein the number of moles of basic groups is less than the number of moles of acid groups in the acid ionomer.
  4. 4. The ionomer coating for eliminating surface charges according to any one of claims 1 to 3, wherein the acidic ionomer is poly 4-vinylbenzenesulfonic acid and the basic groups are provided by a polymer having repeating units of the following formula (I) with positive charges, wherein the number of moles of positive charge groups in the polymer of repeating units is less than the number of moles of acidic groups in the acidic ionomer 。
  5. 5. The ionomer coating for eliminating surface charges according to claim 1, further comprising an epoxy resin auxiliary crosslinking agent, wherein the functionality of the epoxy resin is not less than 2, or wherein the epoxy resin is selected from one or more of the following compounds: Bisphenol a epoxy resin, bisphenol F epoxy resin, polyphenol type glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, alicyclic epoxy resin, diglycidyl phthalate, diglycidyl hexahydrophthalate, epoxidized soybean oil, diglycidyl dimer acid, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, ethylene glycol diglycidyl ether, diglycidyl diglycol diglycidyl ether, 4, 5-epoxycyclohexane-1, 2-dicarboxylic acid diglycidyl ester, 3 ́ - (oxydimethylene) bis (3-ethyl) oxetane, 3, 4-epoxycyclohexylmethyl 3, 4-epoxycyclohexylformate, bis ((3, 4-epoxycyclohexyl) methyl) adipate, 1, 4-cyclohexanedimethanol (3, 4-epoxycyclohexane formate); The molar ratio of the epoxy groups in the epoxy resin to the acid groups in the acid ionomer is 0-0.1.
  6. 6. A method for producing the ionomer coating for eliminating surface charges as defined in any one of claims 1 to 5, characterized in that the production method comprises: uniformly mixing main resin and acid ionomer, adding a main cross-linking agent with hydrogen bond groups and base groups, and co-dissolving in a polar solvent to obtain the ionomer coating for eliminating surface charges; or the preparation method comprises the steps of adding epoxy resin and dissolving in polar solvent.
  7. 7. A coating for removing surface charges, characterized in that the ionomer coating for removing surface charges according to any one of claims 1 to 5 is coated on a substrate including a plastic substrate by blade coating, curtain coating, gravure printing or screen printing, and the solvent is dried at a temperature of 85 ℃ or less to form the coating for removing surface charges.

Description

Ionomer coatings for eliminating surface charge, method for preparing same and corresponding coatings The application is a divisional application of Chinese patent application with the application number of CN202011578812.6, the application date of 2020.12.28 and the application name of ionomer coating for eliminating surface charge, a preparation method thereof and a corresponding coating. Technical Field The invention relates to the technical field of high polymer materials, in particular to an ionomer coating for eliminating surface charges, a preparation method thereof and a corresponding coating. Background Ionomers are polymers of monomers having ionic bonds, and mainly include polymers containing carboxyl groups or polymers containing sulfonic acid groups. It has a certain charge transfer capability, and can be blended in insulating polymer paint to give it its charge conducting capability and eliminate the charge accumulated on the surface of the coating layer due to friction, as shown in figure 1. The acidic ionomer can be dissolved in water or alcohol, and can be mixed with water-soluble paint or alcohol-soluble paint to form a coating with good dispersibility and high transparency. The ionomer has better solubility and dispersion stability than graphite or metal powder, and the coating film is colorless and transparent, thus being suitable for large-scale industrial application. The acidic ionomer may be partially neutralized by adding small amounts of basic compounds including alkali metals, amino groups, quaternary ammonium bases, pyridine derivatives, triazines, 2,4, 6-triphenyl-1, 3, 5-triazines, imidazoles, benzimidazoles, benzotriazoles, oxazoles, polymers with positive charges of the repeating units of formula (I) below. The alkaline compounds may be used alone or in combination. The number of moles of basic groups < the number of moles of acidic groups on the ionomer. The organic amine and basic aromatic ring can increase the solubility of the acidic ionomer in the alcohol solvent and the compatibility with the coating. The basic compound may be, in addition to the small molecule, a conjugated polymer having a positive charge, for example, a polymer of the above formula (I), which has a positive charge dispersed in a plurality of conjugated units, and a homopolymer of 4-vinylbenzenesulfonic acid partially neutralized with the same, which has a greatly improved charge conductivity, as shown in the following formula (II). Such polymers can be incorporated in coatings in lesser amounts (less than 10%) to achieve the effect of eliminating surface charges. However, the acidic ionomers have inherent defects that ionic groups on the ionomers dissociate after absorbing moisture, and because the charges with the same polarity repel each other, the acidic ionomers are separated from each other through peristalsis of molecular chains, microcracks are generated inside the coating film, and the film layer becomes white from transparent. The microcracks block the charge transfer channels, so that the charge eliminating capacity of the coating is quickly reduced, and the service life of the coating is obviously lower than that of a normal coating. The lower the acid ionomer content in the coating, the faster the charge transfer capability decays, the service life is usually not more than one year, and the performance does not meet the industrial requirements. Extending the useful life of acid ionomers requires overcoming the problem of cracking within the coating. In order to improve the tendency of acid ionomer coating films to crack, it is common to add crosslinking agents such as epoxy resins, isocyanates, melamine formaldehyde resins, polyfunctional bases, and the like. However, crosslinking agents which are reactive at room temperature (e.g., isocyanates or polyfunctional bases) are too reactive to allow the coating to gel and have a short shelf life to be used properly. Most crosslinking agents (such as latent isocyanate, melamine formaldehyde resin and epoxy resin) react with acidic groups at 130-150 ℃ and exceed the glass transition temperature of common plastic substrates, so that the crosslinking agents cannot be used on the plastic substrates. Some patents (CN 103348520 a) deal with increasing the molecular weight of ionomers and increasing entanglement. However, too high a molecular weight polymer has too high a viscosity, low solubility, and uniform coating is difficult. The coating requires the use of polymers having a broad molecular weight distribution, and small molecular weight polymers are necessary, so that the improvement effect of this method on the microcracks of the coating film is limited. Therefore, no ideal scheme for eliminating the microcracks of the coating film, prolonging the service life and curing at low temperature is available so far. Disclosure of Invention Aiming at the technical problems that the acid ionomer coating film is easy to generate microcracks and has sho