Diphenol and phenol prills and method for obtaining the same
The invention relates to a novel solid form of diphenol compound. A process for the preparation of diphenol prills having a spherical shape is disclosed. Said process comprising providing a molten composition comprising from 50 to 100 wt. % of a diphenol compound or a mixture of at least two diphenol compounds, and less than 0.1 wt. % of water; forcing said molten composition through at least one droplet generator means to form droplets; and cooling said droplets to form solid diphenol prills. The diphenol prills obtainable by said process are also one subject-matter of the invention.
1. A process for the preparation of prills of one or more compounds of formula (A):
wherein:
y=0 or 1,
R represents a substituent selected from the group consisting of an alkyl group, an alkenyl group, an alkoxy group, a hydroxyalkyl group, an alkoxyalkyl group, a cycloalkyl group, an aryl group, an aryloxy group, an arylalkyl group, a hydroxyl group, a nitro group, a halogen atom, a halo- or perhaloalkyl group, a formyl group, an acyl group, a carboxylic group, an amino group and an amido group,
x=0, 1, 2, 3 or 4,
with the proviso that if y=0, then x=1 and R is an alkoxy or aryloxy group in para position to the hydroxyl group,
said process comprising:
forcing a molten composition comprising from 50 to 100 wt. % of one or more compounds of formula (A) and less than 0.1 wt. % of water through at least one droplet generator means to form droplets; and
cooling said droplets to form solid prills.
2. The process according to claim 1 , wherein y is 0.
3. The process according to claim 2 , wherein the compound according to formula (A) is selected from the group consisting of para-methoxyphenol, para-ethoxyphenol, and para-phenoxyphenol.
4. The process according to claim 2 , wherein said molten composition further comprises from 0 to 50 wt. % of one or more compounds selected from the group consisting of:
diphenol derivatives;
phenol derivatives; and
other organic compounds.
5. The process according to claim 4 , wherein said molten composition comprises:
from 50 to 100 wt. % of para-methoxyphenol, and
from 0 to 50 wt. % of one or more compounds selected from the group consisting of phenothiazine, α-tocopherol, 2-sec-butyl-4,6-dinitrophenol, p-phenylenediamine, and mixtures thereof.
6. The process according to claim 1 , wherein said molten composition further comprises at least one additive selected from the group consisting of antioxidants, antifoams, rust inhibitors, corrosion inhibitors, surfactants, detergents, dispersants, antifouling additives, and anti-deposition agents.
7. The process according to claim 1 , wherein the cooling is carried out by a cooling medium which is a liquefied inert gas and said cooling medium flows co-currently with respect to the droplets of the diphenol composition.
8. The process according to claim 1 , wherein the cooling is carried out by a cooling medium which is a cooling gas, at a temperature of between −40° C. and +100° C., and said cooling medium flows counter-currently with respect to the droplets of the diphenol composition.
9. The process according to claim 1 , wherein the cooling comprises cooling the droplets by a liquefied inert gas and cooling the droplets by a cooling gas.
10. The process according to claim 1 , further comprising a step comprising separating fine particles of diphenol prills having a size of less than 100 μm.
11. The process according to claim 1 , wherein the one or more compounds of formula (A) are each selected from the group consisting of compounds according to formula (I), compounds according to formula (II), and compounds according to formula (III):
wherein x represents 0, 1, 2, 3, or 4, and each R independently represents a substituent selected from the group consisting of an alkyl group, an alkenyl group, an alkoxy group, a hydroxyalkyl group, an alkoxyalkyl group, a cycloalkyl group, an aryl group, an aryloxy group, an arylalkyl group, a hydroxyl group, a nitro group, a halogen atom, a halogeno- or perhalogenoalkyl group, a formyl group, an acyl group, a carboxylic group, an amino group, and an amido group.
12. The process according to claim 1 , wherein the one or more compounds of formula (A) are each selected from the group consisting of pyrocatechol, hydroquinone, resorcinol, pyrogallol, 4-tert-butyl-catechol, tert-butyl-hydroquinone, and mixtures thereof.
13. The process according to claim 1 , wherein said molten composition further comprises from 0 to 50 wt. % of one or more compounds selected from the group consisting of para-methoxyphenol, para-phenoxy-phenol, dibutylhydroxyanisole, 2,6-ditertbutyl-4-methoxyphenol, vanillin, ethyl vanillin, vanillin alcohol, vanillic acid, paradimethoxybenzene, dibutylhydroxytoluene, 2,4-dimethyl-6-tertbutyl-phenol, phenothiazine, tetramethyl piperidinyloxy, hydroxyl-tetramethyl piperidinyloxy, 4-oxo-2,2,6,6-tetramethyl-1-piperidinyloxyl, benzoquinone, and benzoic acid.
14. The process according to claim 13 , wherein said molten composition comprises:
from 50 to 100 wt. % of hydroquinone, and
from 0 to 50 wt. % of one or more compounds selected from the group consisting of para-methoxyphenol, resorcinol, para-phenoxy-phenol, pyrocatechol, dibutylhydroxytoluene, tert-butyl-hydroquinone, 2,6-ditertbutyl-4-methoxyphenol, phenothiazine, and mixtures thereof.
15. The process according to claim 1 , wherein said molten composition further comprises from 0 to 50 wt. % of one or more compounds selected from the group consisting of α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, complexes of copper having an oxidation state of 2; 2-sec-butyl-4,6-dinitrophenol, and p-phenylenediamine.