Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2/00—Processes of polymerisation
  • C08F2/002—Scale prevention in a polymerisation reactor or its auxiliary parts
  • C08F2/004—Scale prevention in a polymerisation reactor or its auxiliary parts by a prior coating on the reactor walls

Definitions

• Anti-fouling agent for the polymerization of olefinic chloride monomers is provided.
• the subject of the present invention is an anti-fouling agent for the polymerization of olefinic chloride monomers.
• the polyvinyl alcohol molecule may be considered as a linear polymer having lateral chains made up of secondary alcoholic functional groups, said secondary alcoholic groups are therefore subject to giving all the characteristic reactions of alcohols, among which is the esterification reaction.
• the present invention refers to a production method of polyvinyl alcohol esters having mono or polyamminic derivatives of benzoic acid; the resulting product may be considered a polyester or an aromatiac polyamino.
• the scope of the present invention is to eliminate the above-mentioned inconveniences.
• a film or coating of amino benzoic esters of polyvinyl alcohol with more or less acetyl is applied on the internal surfaces of the reactor, and the same to be said of all those parts of the reactor such as: the blades and agitater shaft, the thermometric probes, the condenser, the wave-breaking blades, etc.
• the best result is obtained by washing the applied product with water.
• the product which is insoluble in water, precipitates on the walls and the surplus part is washed away.
• An extremely fine, superficial coating which is practically transparent is thus obtained which can be used for several productive phases.
• the aromatic polyamino deposited on the reactor walls in minimum quantities does not influence in any way the polymerization reaction; on the other hand, it protects the walls and the parts which are in contact with the means of reaction and avoids troublesome and costly phenomena of polymer deposit.
• the mechanism by which the aromatic polyaminos prevent the polymer deposit on the internal parts of the reactor during the polymerization of an olefinic monomer in the presence of an olesoluble catalyst, that is, soluble in the same monomer, is still not clear.
• R1,R2,R3 can be H or NH 2 with at least one of the groups substituted by NH 2
• R',R",R'" equal to -H or NO 2 In which at least one of the substituted groups is -NO 2
• the polynitrobenzoil esters of the polyvinyl alcohol is then reduced by triethylammonium-formate in the presence of palladium as catalyst.
• Example 1 A PVC-S polymerization reaction, without the application of an anti-fouling product, is conducted in a 1,500 lit. stainless steel reactor, with the following charging formula:
• Example 2 A solution of nitrobenzoyl-chloride in dimethylformamide maintained at a temperature of 20°C is placed in a flask equipped with agitator, thermometer, condenser and with an adequate thermoregulation system.
• IR IR elementary analysis (analysis under ultraviolet and infrared rays), shows itself to be of the p-NO 2 -benzoic (Paranitrobenzoic) esters of the original, partially acetylised, polyvinyl alcohol.
• the polymer thus obtained is dissolved in acetone (ratio 1:10) after drying.
• the acetonic solution is already ready for industrial uses such as anti-deposit agent, as previously described.
• the product For analytic purposes, the product must be precipitated, washed with water and dried. Whether it is in solution or in the dried state, the product results light-sensitive and easily oxidizable with the formation of various black-bluish, oxidization sub-products.
• Example 2-1 The product obtained from the above-mentioned example is dissolved at 0.8% p/v in 95% ethyl alcohol and 10 parts % p/v of paratoluen-sulfonic (99% strength) are added to the solution thus obtained. This mixture is ready for application at any temperature and by any means to the internal parts of the PVC-S polymerization reactor.
• Example 2.2 In the same reactor, after a thorough cleaning and application of the solution as per example 2-1, the same polymerization charge described as per the characteristics of the present invention has been repeated.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polymerisation Methods In General (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Applications Claiming Priority (2)

Publications (1)

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Cited By (2)

Citations (3)

• 1986
  • 1986-12-24 IT IT83459/86A patent/IT1205543B/it active
• 1987
  • 1987-10-28 WO PCT/IT1987/000090 patent/WO1988005055A1/en unknown

Patent Citations (3)

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