Hydroxyethyl cellulose to make water-based paint (1)
Because the surface-treated hydroxyethyl cellulose is powdery or fibrous solid. When preparing hydroxyethyl cellulose mother liquor, remind you to pay attention to the following points:
(1) Before and after adding hydroxyethyl cellulose, keep stirring until the solution is completely transparent and clear.
(2) Slowly sieve into the mixing tank, do not put a large amount or directly put hydroxyethyl cellulose into the mixing tank.
(3) Water temperature and PH value in water have obvious relationship with the dissolution of hydroxyethyl cellulose, so attention should be paid.
(4) Do not add some alkaline substances to the mixture before the hydroxyethyl cellulose powder is soaked with water. Raising the pH after wetting helps to dissolve.
(5) As much as possible, add antifungal agent in advance.
(6) When using high-viscosity hydroxyethyl cellulose, the concentration of the mother liquor should not be higher than 2.5-3% (by weight), otherwise the mother liquor will be difficult to handle.
3. Prepared into porridge for phenology:
Since organic solvents are poor solvents for hydroxyethyl cellulose, these organic solvents can be used to prepare the porridge. Commonly used organic solvents such as ethylene glycol, propylene glycol, and film formers (such as hexylene glycol or diethylene glycol butyl acetate). Ice water is also a poor solvent, so ice water is often used together with organic liquids to prepare porridge.
Porridge-like hydroxyethyl cellulose can be directly added to the paint. Hydroxyethyl cellulose has been fully soaked in porridge. When added to the paint, it dissolves immediately and acts as a thickener. After adding, keep stirring until the hydroxyethyl cellulose is completely dissolved and uniform. Generally, porridge is made by mixing six parts of organic solvent or ice water with one part of hydroxyethyl cellulose. After about 5-30 minutes, the hydroxyethyl cellulose will be hydrolyzed and swell obviously. In summer, the humidity of general water is too high, so it is not suitable for preparing porridge.
Factors affecting the viscosity of latex paint:
1 The more air bubbles remain in the paint, the higher the viscosity.
2 Whether the amount of surfactant and water used in the paint formula is appropriate.
3 When synthesizing latex, the amount of oxides such as residual catalysts.
4 The amount of other natural thickeners in the paint formulation and the ratio of the amount of hydroxyethyl cellulose.
5 In the paint making process, whether the sequence of adding thickener is appropriate.
6 Humidity overheated during dispersion due to excessive agitation.
7 Corrosion of thickener by microorganisms.
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