Commonly used film-forming aids are Texanol, Lusolvan FBH, Coasol, DBE-IB, DPnB, DOWANOL PPh, alcohol ester 12, etc., and Texanol is often used as a comparison benchmark.
Most companies in China use Texanol and domestic alcohol esters12. Although the film-forming aid has a great effect on the film formation of the latex paint, the film-forming aid is an organic solvent and has an impact on the environment, so the development direction is an environmentally-friendly and effective film-forming aid.
The first is to reduce odor. Coasol, DBE-IB, Optifilm Enhancer 300, TXIB, TXIB and Texanol blends all reduce odor. Although TXIB is slightly inferior in reducing MFT and early scrub resistance, it can be improved in these areas by mixing with Texanol.
The second is to reduce volatile organic compounds (VOC). In Europe, VOC refers to those chemicals whose boiling point is equal to or lower than 250 ° C. Those substances whose boiling point exceeds 250 ° C are not included in the category of VOC, so the film-forming aids are developed to high boiling points. Such as Coasol, Lusolvan FBH, DBE-IB, Optifilm Enhancer 300, diisopropanol adipate.
The third is low toxicity, safety and acceptable biodegradability. Table 1 shows the toxicity of the film-forming aids.
Table 1 Toxicity of film-forming additives
Fourth, active film-forming aids. Dicyclopentenyl oxyethyl acrylate (DPOA) is an unsaturated polymerizable organic matter. The homopolymer has a Tg of 33 ° C and is odorless.
In latex paint formulations with a higher Tg value, no film-forming aid is needed, and DPOA is added, and a small amount of drier, such as a cobalt salt, is added. DPOA can reduce the film-forming temperature and make latex paint film-forming at room temperature. However, DPOA is non-volatile and not only environmentally friendly, but also undergoes oxidative radical polymerization under the action of a drier, which increases the hardness, anti-stickiness and brightness of the coating film. Therefore, DPOA is called an active film-forming aid.