The use of Flame Retardant Agent methods mainly include the surface pretreatment method and direct addition method, the former is diluted with coupling Agent treatment filler surface, which is a premixed resin and filler, join the coupling Agent of concentrate.
(1) surface pretreatment
Will Flame Retardant Agent at 0.5 ~ 1% concentration of dilute solution, when used in clean glued surface coated with a thin layer of glue after drying. Solvents used for water and alcohol (methoxy silane choose methanol, ethoxy silane choose ethanol), water or alcohol mixture, and with no water containing fluorine ion and cheap and non-toxic ethanol, isopropanol is advisable. Besides ammonia hydroxyl silane, by other Flame Retardant Agent dispensing solution are added to acetic acid hydrolysis catalyst, and the pH value to 3.5 ~ 5.5. Long chain alkyl and phenylsilane are not suitable for water solution because of their poor stability. The hydrolysis of chlorosilane and ethoxy silane is accompanied by severe condensation reaction, and it is not suitable to be used in water solution or water alcohol solution. Water soluble low Flame Retardant Agent, can join the first 0.1 ~ 0.2% (mass fraction) of nonionic surface active Agent, and then adding water into water emulsion is used.
Flame Retardant Agent into the solution, is advantageous to the Flame Retardant Agent on the surface of the material, dispersion, solvent is a mixture of water and alcohol solution, the solution is commonly silane (20%), alcohol (72%), water (8%), alcohol is commonly ethanol (to ethoxy silane) methanol (methoxy silane) and isopropanol (to not easily soluble in ethanol, methanol silane) by silane hydrolysis velocity is related to PH value, the slowest neutral, acid, alkali is faster, so generally need to adjust the PH value of solution, in addition to the amino silane, Other silane can be added with a small amount of acetic acid to adjust PH to 4-5. Amino silane is alkaline and need not be adjusted. Because silane hydrolysis, cannot long store, had better match now use, had better use up in an hour.
(2) add methods directly
The Flame Retardant Agent directly added to the adhesive composition, for the amount of matrix resin for the amount of general 1 ~ 5%. Depending on the diffusion of the molecules, the coupling agent molecules migrate to the bonding interface for coupling. For the adhesive that needs to be cured, it needs to be put on for a period of time before curing, so that the coupling agent can complete the migration process, so as to obtain a better effect. In practice, couplers often form a sedimentary layer on the surface, but what really matters is the monomolecular layer, so the dosage of couplers need not be excessive.