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CN-121995043-A - Control method for improving cracking resistance of thick paste coating

CN121995043ACN 121995043 ACN121995043 ACN 121995043ACN-121995043-A

Abstract

The invention discloses a control method for improving cracking resistance of thick-film coating, which comprises the following steps of sequentially applying and maintaining primer and thick-film coating on a substrate to obtain a test sample, testing the test sample under the conditions of air supply and heating to obtain the crack condition of the surface of the test sample after the test is finished, grading according to the crack condition to obtain a cracking grade, obtaining an adaptive construction condition and an adaptive service condition according to the cracking grade, and controlling the thick-film coating to perform construction and service under the adaptive construction condition and the adaptive service condition. Aiming at the problem that the thick-paste coating is easy to crack in the use process due to thick construction thickness, bad outdoor service conditions and the like, the cracking performance of the thick-paste coating is tested in advance under the condition of rapid drying of air supply and heating, the cracking risk of a coating system is rapidly identified, the adaptive application scene of the thick-paste coating is screened out, and the cracking resistance of the thick-paste coating in the actual use process is effectively improved.

Inventors

  • JIANG YUE
  • ZHAO RUNLIN
  • SONG KAI

Assignees

  • 广州立邦涂料有限公司

Dates

Publication Date
20260508
Application Date
20260114

Claims (10)

  1. 1. A control method for improving cracking resistance of thick paste paint is characterized by comprising the following steps: the method comprises the steps of testing the surface of a substrate, namely sequentially applying and curing a primer and a thick paste coating on the substrate to obtain a test sample, testing the test sample under the conditions of air supply and heating to obtain the crack condition of the surface of the test sample after the test is finished, and grading according to the crack condition to obtain the crack grade; The process control comprises the steps of obtaining an adaptive construction condition and a service condition according to the cracking grade, controlling the thick paste coating to carry out construction and service under the adaptive construction condition and the service condition, wherein the construction condition comprises at least one of a substrate type, a primer application amount or a thick paste coating application amount, and the service condition comprises an air supply speed, a heating temperature or a combination thereof.
  2. 2. The control method according to claim 1, wherein the crack conditions include the length and the number of cracks, wherein the number of cracks having a length of 5mm or less per dm 2 of the test specimen surface is denoted as M, the number of cracks having a length of >5mm is denoted as N, and wherein the crack performance grade is obtained by sequentially ranking the following criteria: 1) Level 0, m=0, n=0; 2) Level 1, M is less than or equal to 2, and N is less than or equal to 1; 3) 2 stages, wherein M is less than or equal to 4, and N is less than or equal to 1; 4) 3 stages, wherein M is less than or equal to 6, and N is less than or equal to 2; 5) Grade 4, M is less than or equal to 6, and N is less than or equal to 3; 6) Stage 5, M >6, or N >3.
  3. 3. The control method according to claim 2, wherein the adapted construction conditions and service conditions are those adopted for the cracking test when the cracking grade is grade 0, grade 1 or grade 2.
  4. 4. The control method according to claim 1, wherein in the cracking test, a wind speed of the air supply is 1 to 10m/s.
  5. 5. The control method according to claim 1, wherein the temperature of the heating in the cracking test is 30 to 60 ℃.
  6. 6. The method according to claim 1, wherein the curing conditions of the primer in the cracking test are a temperature of 23±2 ℃, a humidity of 50±5% and a time of 2 to 4 hours.
  7. 7. The control method according to claim 1, wherein in the cracking test, the curing condition of the thick paste coating is a temperature of 23+ -2 ℃, a humidity of 50+ -5% and a time of 24-48 hours.
  8. 8. The control method according to claim 1, wherein the primer is applied in an amount of 80 to 120g/m 2 in the cracking test.
  9. 9. The control method according to claim 1, wherein in the cracking property test, the application amount of the thick paste paint is 600 to 1000g/m 2 .
  10. 10. The control method of claim 1, wherein in the cracking test, the substrate comprises at least one of an asbestos-free fiber cement substrate, a metal substrate, a tile substrate, an exterior wall putty-coated substrate, a coating-coated substrate, a concrete substrate, or a brickwork substrate; and/or, in the dehiscence test, the primer comprises a film-forming primer or a penetrating primer.

Description

Control method for improving cracking resistance of thick paste coating Technical Field The invention belongs to the technical field of coatings, and particularly relates to a control method for improving cracking resistance of a thick-film coating. Background The thick paste texture coating has a thicker construction thickness, is affected by the change of internal and external stress of the coating under the severe environments of long-term outdoor insolation, wind and rain showering, large day and night temperature difference and the like, and can generate the cracking problem on the surface, so that the problems of poor appearance, customer complaints and the like are caused. However, the laboratory cannot test the problem of cracking of thick paste texture paint in high Wen Baoshai environments, and the matching solution cannot be provided specifically. The detection standard of the thick paste texture coating GB/T9779-2015 multi-layer building coating at present has the requirement of 3h drying and no crack on the initial cracking resistance of the product in the 6.10 th part. However, the initial cracking resistance test can only represent the initial cracking resistance of the product after construction under standard conditions, can not well simulate the cracking resistance of the product under outdoor high-temperature exposure, and has no special test standard for determining the cracking resistance test standard and test method of the thick-film coating under high-temperature conditions. Disclosure of Invention In order to overcome at least one of the problems of the prior art, the present invention aims to provide a control method for improving the cracking resistance of a thick paste coating. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the first aspect of the invention provides a control method for improving the cracking resistance of a thick paste coating, comprising the following steps: the method comprises the steps of testing the surface of a substrate, namely sequentially applying and curing a primer and a thick paste coating on the substrate to obtain a test sample, testing the test sample under the conditions of air supply and heating to obtain the crack condition of the surface of the test sample after the test is finished, and grading according to the crack condition to obtain the crack grade; The process control comprises the steps of obtaining an adaptive construction condition and a service condition according to the cracking grade, controlling the thick paste coating to carry out construction and service under the adaptive construction condition and the service condition, wherein the construction condition comprises at least one of a substrate type, a primer application amount or a thick paste coating application amount, and the service condition comprises an air supply speed, a heating temperature or a combination thereof. In some embodiments of the invention, the crack conditions include the length and number of cracks, where the number of cracks with a length of less than or equal to 5mm is denoted as M and the number of cracks with a length of >5mm is denoted as N, and the cracking ratings are obtained by ranking in order using the following criteria: 1) Level 0, m=0, n=0; 2) Level 1, M is less than or equal to 2, and N is less than or equal to 1; 3) 2 stages, wherein M is less than or equal to 4, and N is less than or equal to 1; 4) 3 stages, wherein M is less than or equal to 6, and N is less than or equal to 2; 5) Grade 4, M is less than or equal to 6, and N is less than or equal to 3; 6) Stage 5, M >6, or N >3. In some embodiments of the invention, the adapted construction and service conditions are those employed by the dehiscence test when the dehiscence grade is grade 0, grade 1 or grade 2. In some embodiments of the invention, the dehiscence test is performed in a drying room provided with a wind tunnel machine, the test sample is placed in the wind tunnel machine for testing, the wind speed of the air supply is regulated by the wind tunnel machine, and the heating temperature is regulated by the drying room. In some embodiments of the present invention, in the cracking test, the wind speed of the air supply is 1-10 m/s. In some embodiments of the invention, the temperature of the heating is 30-60 ℃ in the cracking test. In some embodiments of the invention, the curing conditions of the primer in the cracking test are 23+/-2 ℃ and 50+/-5% humidity for 2-4 hours. In some embodiments of the invention, the curing conditions of the thick paste coating are 23+/-2 ℃ and 50+/-5% of humidity for 24-48 hours in the cracking test. In some embodiments of the invention, the primer is applied in an amount of 80 to 120g/m 2 in the dehiscence test. In some embodiments of the invention, the amount of the thick paste coating applied in the cracking test is 600-1000 g/m 2. In some embodiments of the invention, the substrate comprise