WO2014181346A4

WO2014181346A4 - A process for manufacturing of boehmite particulate material

Info

Publication number: WO2014181346A4
Application number: PCT/IN2014/000260
Authority: WO
Inventors: Jashvant Ishvarlal SEVAK; Vinayak Mahadeo NATU
Original assignee: Heubach Colour Pvt. Ltd.
Priority date: 2013-04-23
Filing date: 2014-04-22
Publication date: 2015-04-30
Also published as: IN2013MU01494A; WO2014181346A2; WO2014181346A3

Abstract

A process for the preparation of Boehmite particulate material from the waste containing Aluminium chloride, Aluminium sulfate, Aluminium carbide or any other Aluminium salt; said process comprising : a. preparing 2 to 15 wt. % of aqueous slurry of Aluminium hydroxide, said Aluminium hydroxide is recovered from the waste containing Aluminium chloride, Aluminium sulfate, Aluminium carbide or any other Aluminium salt by hydrolyzing the waste with soda ash; b. preparing slurry containing 2 to 10 wt. % of silane and 2 to 10% of silica by making 2 to 10 wt. % of aqueous slurry of silane with stirring followed by adding 2 to 10 wt. % of micro fine precipitated silica powder having average particle size of 3μ and stirring the slurry over night at low speed; c. Mixing slurry obtained in step (a) into step (b) followed by subjecting the reaction mixture to hydrothermal treatment at temperature in the range of 90°C to 250°C for at least 4 hours; and d. collecting Boehmite particulate material by either centrifuging or filter pressing the reaction mixture or any other conventional means followed by drying the product by either spray drying or spin flash drying or any other conventional means and optionally pulverizing to get fine flaky particles with particle size 5 to 8 micron. Boehmite particulate matter having 80 to 84 wt. % of Boehmite along with base material as micro fine precipitated silica powder (8 to 10 wt. %) treated with silane (8 to 10 wt. %) with preferred particles size 5 to 8 microns and a coating comprising thereof.

Claims

AMENDED CLAIMS received by the International Bureau on 20 February 2015 (20.02.2015) We Claim,

1. A process for the preparation of Boehmite particulate material from the waste containing Aluminium chloride;

said process comprising :

a. preparing 2 to 15 wt. % of aqueous slurry of Aluminium hydroxide, said Aluminium hydroxide recovered from the waste containing Aluminium chloride by hydrolyzing the waste with soda ash;

b. preparing slurry containing 2 to 10 wt.% of silane and 2 to 10 wt. % of silica by making 2 to 10 wt. % of aqueous slurry of silane with stirring followed by adding 2 to 10 wt. % of micro fine precipitated silica powder having average particle size of 3μ and stirring the slurry over night at low speed; c. mixing slurry obtained in step (a) into step (b) followed by subjecting the reaction mixture to hydrothermal treatment at temperature in the range of 90°C to 250° C for at least 4 hours; and

d. collecting Boehmite particulate material by either centrifuging or filter pressing the reaction mixture or any other conventional means followed by drying the product by either spray drying or spin flash drying and optionally pulverizing to get fine flaky particles with particle size 5 to 8 micron.

2. The process as claimed in claim 1, wherein the step (a) comprises recovering Aluminium hydroxide from the waste, a mother liquor containing Aluminium chloride by hydrolyzing the waste with soda ash followed by filtering the product by filter press followed by spray drying to obtain Aluminium hydroxide.

3. The process as claimed in claim 1, wherein the step (a) comprises preparing 4 wt. % of aqueous slurry of Aluminium hydroxide powder by adding Aluminium hydroxide in water.

4. The process as claimed in claim 1, wherein step (b) comprises adding 3 to 5 wt. % of silane in water followed by stirring the slurry for at least 30 minutes followed by

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adding 10% of micro fine precipitated silica powder having average particle size of 3μ and stirring the slurry for at least for 4 to 16 hours at 30 rpm speed.

5. The process as claimed in claim 1, wherein the silane used in the step (b) is selected from dimethyl silane, vinyl silane, and polyvinyl silane.

6. The process as claimed in claim 1 wherein, the silane used in the step (b) is vinyl silane.

7. The process as claimed in claim 1, wherein step (c) of hydrothermal treatment is carried out at temperature of 130°C for at least 4 hours.

8. The process as claimed in claim 1, wherein waste used in the step (a) is a mother liquor of CPC Green containing Aluminium chloride.

9. Boehmite particulate matter having 80 to 84 wt. % of Boehmite along with base material as micro fine precipitated silica powder (8 to 10 wt. %) treated with silane (8 to 10 wt. %) with preferred particles size 5 to 8 micron having characteristic peaks of XRD at 14.475, 14.051, 49.224, 28.209 and 5.863 Angle, 2-Theta°.

10. A coating composition comprising 3 to 5 % of Boehmite particulate matter as claimed in claim 9 and prepared according to claims 1 to 8 having matting affect with gloss reduction i.e. 6-17% as compared to standard matting agent.

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Statement under Article 19

This has the reference of PCT/IS A/220 with respect to PCT/IN2014/000260. Our reply comprising invention, inventive step and amendments carried out in the claims are as under:

The current invention relates to process for preparation of Boehmite particulate material from waste containing aluminium chloride wherein 2-15% of aqueous slurry of aluminium hydroxide is recovered by treating waste with soda ash; preparing slurry of 2-10% wt. of silane and 2-10 % wt. of silica having average particle size of 3μ by stirring overnight at low speed; mixing both slurries and subjecting to hydrothermal treatment at 90-250°C for at least 4 hours and finally drying by either spray or spin flash drying optionally followed by pulverizing to get fine flaky particles with size 5-8μ.

The inventive step here is silane coats allover silica which increases affinity between silica and boehmite, which will not allow boehmite to agglomerate while conversion and produce flaky fine particles directly. The invention has 80-85% boehmite, 8-10% silica and 8-10% silane having particle size 5-8μ. Boehmite of invention shows excellent gloss reduction i.e. 6-17% as compared to standard.

We have amended claim 10 to bring out clarity with respect to matting effect and supported by the examples, particularly Table 1.

Therefore, claims 9-10 are novel and 1-10 are inventive.

According to Sec. 4.1, we have restricted Claim 1 to waste material containing aluminium chloride only.

According to Sec. 4.2, we have amended Claim 4 by adding 3-5% of silane so as to bring clarity. According to Sec. 4.3, we have also deleted expression "and the like" from Claim 5. 24

According to Sec.4.4, we have amended claim 10 as follows:

10. A coating composition comprising 3 to 5 % of Boehmite particulate matter as claimed in claim 9 and prepared according to claims 1 to 8 having matting affect with gloss reduction i.e. 6 - 17 % as compared to standard matting agent.

We have amended claim 10 to bring out clarity with respect to matting effect and supported by the examples, particualrly Table 1. Boehmite particulate matter of invention shows excellent gloss reduction i.e. 6-17% as compared to standard.

Therefore, claim 10 is novel and inventive.