GUIDE TO IMPROVING PRODUCTS AND PROCESSES WITH DUPONT L U D O X COLLOIDAL SILICAS "Ludox" finds application in a diversity of industrial processes and formulations. Its utility often comes from its high surface area, its reactivity in the colloidal state and its inertness when dry.
H o w Ludox improves the high temperature performance of inorganic fibers a n d c e r a m i c systems As a binder for high temperature ceramics as well as for inorganic or organic fibers in a matrix, Du Pont "Ludox" offers a number of advantages over or ganic binders. The colloidal spheres of "Ludox," which are 9 9 % pure silica, have a coefficient of linear thermal expansion of about 0.3 χ 10" 6 in./in./°F., there fore, the bonds formed with them have exceptional dimensional stability. Also "Ludox" undergoes no phase transitions over a broad temperature range and has such a low coefficient of thermal expansion that it makes a sys tem unusually resistant to thermal shock. The surface-active colloidal particles of "Ludox" bond well to aluminosilicate and glass fibers, and many ceramic powders and flours. Recent exam ples of this include: fused silica, spodumene, zircon and glass frits. Bonds made with "Ludox" are strong up to the 3200 F. range and water insensitive. Generally the bonding strength increases with an increase in the amount of solids from "Ludox," as shown in the chart below.
How Ludox improves other products and processes All types of "Ludox" are stable and com patible with anionic and non-ionic sys tems. They differ in type of stabilizing ion, particle size, concentration of silica, and surface modification.
LUDOX® fortifies floor polishes "Ludox" is well established in floor pol ish manufacturing. It contributes long lasting slip resistance while maintaining a satisfactory balance of other perfor mance properties.
LUDOX® frictionizes many surfaces Fiber, paper and film can all be frictionized by a treatment with "Ludox." Great est commercial interest centers on treated paper bags, folding cartons and corru gated and solid fiber containers. Selec tion of the form of "Ludox" to use de pends on application.
LUDOX® aids elastomeric systems
•s3
200
/
100 P-l
"Ludox" has unusual modifying and re inforcing characteristics in elastomer systems. It can improve the bonding of adhesives; improve the adhesion, abra sion resistance and water resistance of coatings and saturates; increase the modulus of latex deposits and decrease their tack.
LUDOX®AM improves film-forming
Λ
/
Ο η
0 2 4 6 8 10 12 14 16 % "Ludox" Solids on Typical Glass Fabric And, since it is completely inorganic, the unusual binding and reinforc ing properties achieved with "Ludox" are not lost due to "burn-out" upon ex posure to high temperatures. This holds true whether "Ludox" is applied in diluted solutions or in combination with inerts. Since it's an aqueous dispersion of high purity colloidal amorphous silica, "Ludox" is compatible with most ceramic fibers and aggregates. In fact, it can often be used as the only bonding agent, since it is completely non-fugi tive and usually provides sufficient dry-strength as it coalesces on dry-down. Optimum bonding is achieved by a high temperature (350°-400°F) bake.
polymers "Ludox" AM improves both the adhesion and formation of polymer films. It eliminates mud cracking at high temperatures, allowing you to use heat drying in production, which is both faster and simpler; reduces the tack and improves the water holdout and wet abrasion resistance of the films.
LUDOX®and your products or processes For more information about "Ludox" colloidal silicas, send the cou pon. For a sample, please write on your letterhead. Du Pont Company Room 2339 Wilmington, Del. 19898 |
I am interested in LUDOX for_
| Name BETTER T H I N G S FOR BETTER LIVING . . . THROUGH REG. U.S. PAT. OFF.
CHEMISTRY
I Title I Company
J Street. City_
_State_
-Zip-
C&EN
83
