The specific gravity of the dried hydrate is 2.43 and the refractive index is 1.535. The pH value is 6-3 to 6-7 and that signfies that the product is acidic in chemical behavior and has livering tendency. To overcome this problem, H.KOHSTAMN & Co., Inc. U.S.A. developed a special quality which is less prone to liver than the preceding grade. The pH value of this quality is 6.8 to 7.4 and has completely replaced the preceding grade among printing ink manufacturers.

This improved quality is now manufactured in INDIA by  MARATHWADA CHEMICAL INDUSTRIES (P) LTD. and marketed as “ALUMINA HYDRATE - 1512"

SPECIFIC GRAVITY	2.43
BULK DENSITY	0.32
OIL ABSORPTION	65 +/- 5 per 100 gms.
pH	6.8 to 9
MOISTURE RESIDUE ON SIEVE	22 to 26 %
OF 240 MESH	Max. 1 %
LIVERING	As per std. sample
TRANSPARENCY	As per std. sample
WHITISHNESS	As per std. sample
REFRACTIVE INDEX	1.535

4 Microne	93.8 %
2 Microne	84.4 %
1 Microne	53.1 %
0.5 Microne	39.0 %
0.2 Microne	35.9 %
0.1 Microne	32.8 %

It has been observed that ALUMINA HYDRATE improves the finish of dried ink films. If gloss varnish can be used, the addition of same increases the finish still further. A combination of hydrate and gloss varnish is frequently used.

Because the ALUMINA HYDRATE has acidic properties, it does not change appreciably the acidity of the lithographic fountain solution during the printing operation. The hydrate is therefore a useful ingredient in lithographic inks.

In multicolour printing where inks trap over each other, it is obviously an advantage to have transparent inks after the first one. ALUMINA HYDRATE qualifies very well as a transparent extender when an ink needs to be reduced in colour strength for multicolour printing.

The majority of the moisture-set inks (often called steam-set inks) contain a resin that is very acidic in nature. This resin is a fumarated resin and has an acid value that is over 300.

In a number of inks, a blend of clay and ALUMINA HYDRATE can be used as the extender to arrive at a low cost and acceptable printing qualities. However, if the printing run be a long one, it is safer to select a good printing extender to prevent piling on the rollers and on the printing plates.

More present day pigments are faded or changed in hue by alkaline substances than by acidic ones. The majority of the Triphenylmethane and Diphenylmethane pigments, such as Methyl Violet and Alkali Blue, shift their chemical structures to the colourless state when alkali is present.

The popular Iron Ferrocyanide Blues readily fade with alkalies. The use of ALUMINA HYDRATE , is a safeguard in cases where alkaline materials can be activated by the presence of sufficient moisture that can yield fading of sensitive pigments.

MARATHWADA CHEMICAL’S 1512 ALUMINA HYDRATE has a reduced reactivity. An accelerated test can be conducted of the ink at 160 o F during three days to examine the possibility of livering, either on storage or during hot milling.

Many of the resins that formerly livered with ALUMINA HYDRATE have in the recent years been improved so liv thatering has been eliminated. Therefore, the selection of Hydrate can be made in many resinsolvent in inks that formerly could not tolerate this extender.

It has been observed that ALUMINA HYDRATE yields drier dissipation in drying oil inks. This means that the potency of the drier in the ink loses its catalytic power either upon aging or upon hot milling.

ALUMINA HYDRATE-1512 finds many application as an Extender & Filler Pigment in PAPER, LEATHER CLOTH,COSMETICS, CRAYONS, MATCH CHEMICALS, POLISHING AGENTS, CERAMICS AND REFRACTORY, CERAMIC COLOURS, ADHESIVES, RUBBER, PAINTS etc....

NOTE : The tests and results shown were conducted in our laboratories. They do not constitute a guarantee and it is suggested that you carry out your own evaluations prior to the adoption of these products.

NOTE : The products are offered without patent protection. For this reason and before submitting orders, it is purchaser’s responsibility to ensure that products requested are not covered by any patent in his country.