Societa' Italiana Resine S.i.r. S.p.a.

Ausidet S.r.l.

Mira Lanza S.p.a.

Enichem Augusta Industriale S.r.l.

Paolo Colombo

Pierino Radici

Sergio Custro

Gaudenzio Bianchi

Daniele Colombo

Umberto Santini

Mario Ermoni

Claudio Troglia

Romano Baroffio

Pier D Mattioli

Ugo Nistri

Jacob Ackermann

Luigi Valtorta

Santina R Verzellino

Giuseppe Muratori

Pietro Erini

Stable aqueous suspensions of zeolite 4A which can be easily pumped, containing from 0.5 to 65% of zeolite and from 0.05 to 6 g (per 100 g of zeolite) of a suspending agent, composed of mixtures of ethoxylated alkanols, said mixtures being obtained by ethoxylating: a) biodegradable branched alkanols, having from 10 to 18 carbon atoms and having a single branching in position 2, said mixtures containing at least 2 alkanols having a different number of C atoms; or b) mixtures containing 40-100% of branched alkanols as in a) and 60-0% of linear alkanols having from 10 to 18 C atoms.

Stable aqueous suspensions of zeolite which can be easily pumped

A process for the manufacture of aqueous solutions of anti-scaling agents, starting from maleic anhydride and vinyl acetate (and optionally from a third monomer), characterized in that:

Process for the manufacture of aqueous solutions of anti-scaling agents

Transesterified copolymers of maleic anhydride, particularly useful in the field of detergency and anti-scaling agents, obtained from preformed copolymers of maleic anhydride with vinyl acetate, by at least partial transesterification of said preformed copolymers.

Transesterified copolymers of maleic anhydride, particularly useful in

A process for the production of a bleaching activator in granular form, in which an aqueous suspension of acetylated bleach activator is filtered to recover a filtration cake comprised of the acetylated bleach activator and having a moisture content of from 20 to 65% by weight; from 1 to 7 parts by weight of the filtration cake of step (a) is mixed and granulated with 1 part by weight of sodium tripolyphosphate in a granulator means to provide a granulated product; and the granulated product is dried to a residual moisture content of from 5 to 15% by weight to obtain the bleaching activator.

Process for the preparation of a bleaching activator in granular form

Polyformaldehyde is prepared by polymerizing anhydrous monomeric formaldehyde in an organic, liquid and inert diluent which is a non-solvent for polyformaldehyde, in the presence of a catalyst of the formula: ##STR1## wherein A.sup.(-) is a lactamate group: ##STR2## in which PM is a linear polymethylene chain with from 3 to 13 carbon atoms, possibly substituted with one or more alkyl, cycloalkyl, aryl or alkylaryl radicals, and wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 independently are an alkyl, cycloalkyl, aryl or alkylaryl radical.

Process for the polymerization of formaldehyde

The terminal hydroxyl groups of an acetal polymer are esterified or etherified by reaction with an end-capping agent chosen from anhydrides of carboxylic acids, orthoesters and orthocarbonates, by forming an intimate mixture of polymer in powder form and liquid end-capping agent, the amount of said agent in the mixture being less than that which results in loss of the free-flowing characteristics of the powder, and reacting said mixture under stirring at 50.degree.-170.degree. C.

Process for improving the stability of acetal polymers

Raw gaseous formaldehyde is purified by passing it through a first series of superimposed fluidized beds of solid adsorbent, maintained at 80.degree.-140.degree. C., while continuously circulating solid adsorbent from each bed to the underlying bed and discharging from the lowermost bed the spent adsorbent, delivering the latter to the uppermost bed of a second series of superimposed fluidized beds of solid adsorbent, passing through the latter a stream of inert gas to strip the adsorbed formaldehyde at 130.degree.-150.degree. C., while continuously circulating said spent adsorbent from each bed to the underlying bed and discharging from the lowermost bed the adsorbent thus treated, delivering the latter to the uppermost bed of a third series of fluidized beds of solid adsorbent, and passing through the latter a stream of inert gas to regenerate the adsorbent at 145.degree.-250.degree. C., while continuously circulating the adsorbent from each bed to the underlying bed, discharging the regenerated adsorbent from the lowermost bed and recycling said regenerated adsorbent to the uppermost bed of the first series.

Process for purifying gaseous formaldehyde

Block copolymer of the structure A-B wherein:

Block copolymers

The thermal and chemical stability of etherified acetal homopolymers is improved by heat-treating the latter in the molten state at a temperature of at least 180.degree. C., in the presence of a halide of an alkali or alkaline earth metal, until substantially complete degradation of the unstable polyoxymethylene chains.

Process for improving the stability of etherified acetal homopolymers

An etherified acetal homopolymer is stabilized by heat-treating said homopolymer suspended in a liquid diluent chosen from water or mixtures thereof with polar organic compounds, preferably in the presence of a basic compound, at a temperature of 100.degree.-160.degree. C and below the melting point of the homopolymer, thereby to substantially degrade the unstable fraction of said homopolymer.

The unstable terminal hydroxyl groups of acetal polymers are etherified in a liquid reaction medium in the presence of organic additives.

Process for the preparation of etherified acetal polymers

Formaldehyde present in a waste water containing lower carboxylic acids is recovered by reacting said waste water at 0.degree. to 90.degree. C. with the amount of ammonia required for converting said formaldehyde into hexamine and the latter is recovered in solid form by evaporating the resulting solution. The solid hexamine thus recovered has a content in lower carboxylic acids not exceeding 0.05 wt.%, is practically free from other impurities and is suited for any conventional use.

Process for the recovery of formaldehyde present in waste waters

Process for the separation of trioxane from aqueous solutions containing it together with formaldehyde, which comprises subjecting the said solutions to evaporation at temperatures of 100.degree. C or lower, at pressures lower than atmospheric, and with residence times of less than 1 minute under the evaporation conditions, with vaporization of a quantity of from about 5 to about 15% by weight of the solution introduced, and recovering the trioxane from the products evaporated in this way.

Plural stage recovery of trioxane in a process having a molecular

Block copolymer of the structure A-B, wherein: ##STR1## A is a polylactamic block of recurring units: t,0010 WHEREIN PM is a linear polymethylene chain having from 3 to 13 carbon atoms, B is a polyoxymethylene block of recurring units [CH.sub.2 O]. The block copolymer contains at least 2 wt.% of block B and at least 0.05 wt.% of block A. The block copolymer can be used as technopolymer when rich in block B, or in the field of yarns and molded products when rich in block A.

A novel block copolymer HO--D--A--B--D--H, wherein

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Saronno, Italy

Paolo Colombo