Solvent Thixotropy Thickener LD-7003
Solvent Thixotropy Thickener LD-7003
First, properties and applications
LD-2003 can produce high thixotropy in solvent varnish which of course finally decided by types of solvents. The solvents should mainly contain 200# solvent gasoline and aromatic solvents and adequately compounded by some esters, ketones and alcohols.
LD-2003 can be used for solventless system like epoxy resins, plastisol, joint filler, putty and knife fillers’ rheology conditioner and it has the advantage of standing high operating temperature, especially when the solvent is mainly 200# solvent gasoline, the merit is obvious.
LD-2003 shows the best temperature stability, for example, the alkyd resin paint. Then when the system solvent is mainly aromatic hydrocarbon like paints based on chlorinated rubber, polyethylene copolyme, chlorinated polyethylene, its temperature stability reduces slightly.
Second, usage and dosage
The general dosage is 0.2-2.0% for the finished paint, but the accurate amount is decided by the required viscosity of paints. As the facts proved, paints’ thixotropy affects the fluidity, so we must make it reach the balance. It’s better to use LD-2003 in the high-speed grinder, usually add powdered LD-2003 in the mixture of solvents and base materials, predisperse for about 5 minutes, then add in pigments to grind. Another way is to make LD-2003 thickener in advance. In order to ensure thickener’s adequate dispersion, following items should be noticed: ①require sufficient shear force to reach adequate dispersion; ②there is specific temperature limit to grinding, pure agitation can not make the whole system even, even though in the form of gel. Usually it needs sanding or other sanding methods to disperse the system sufficiently.
Third, basic requirements
When using this thickener in paints whose solvents mainly is 200﹟solvent gasoline, the operating temperature is 50-60℃. Simultaneously cooperated with certain shear force, such paints especially alkyd resin paint can produce out-bound thixotropy in the limited temperature. Operating under the temperature of 80-90℃for a short time won’t make any harmful effects.
When using LD-2003 in paints containing aromatic solvents like chlorinated rubber, the best temperature is slightly low, about 40-60℃, short-time high temperature(80℃) has no lacerative influences. As the properties changes with different kinds of paints, users must carry out related experiments to define the best usage. Not only can it be used in powder form, but also in the form of pre-gel. Using pre-gel can make better dispersion effect, however, it still needs superpower shear and must be within the temperature range.
The accurate method of making pre-gel is as follows: one share of LD-2003 strongly stirs with three shares of xylene(or other aromatic solvent), stir strongly until form high-viscous paste, add four shares of xylene, stir strongly for about 10 minutes, and after a maturation lasting nearly 12 hours, a translucent and even paste is well produced which can keep stable in a longer time.
