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
  • C08F2/005—Scale prevention in a polymerisation reactor or its auxiliary parts by addition of a scale inhibitor to the polymerisation medium
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D279/00—Heterocyclic compounds containing six-membered rings having one nitrogen atom and one sulfur atom as the only ring hetero atoms
  • C07D279/10—1,4-Thiazines; Hydrogenated 1,4-thiazines
  • C07D279/14—1,4-Thiazines; Hydrogenated 1,4-thiazines condensed with carbocyclic rings or ring systems
  • C07D279/18—[b, e]-condensed with two six-membered rings
  • C07D279/20—[b, e]-condensed with two six-membered rings with hydrogen atoms directly attached to the ring nitrogen atom
• • 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
  • C08F14/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen
  • C08F14/02—Monomers containing chlorine
  • C08F14/04—Monomers containing two carbon atoms
  • C08F14/06—Vinyl chloride
• • 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

• U. S. Patent Nos. 4,853,446 and 4,855,424 disclose and claim novel compounds and compositions which have been found to inhibit the build-up of scale on the walls of vinyl chloride polymerization reactors. Such reactor scale interferes with heat transfer, and consumes valuable monomer which is lost to the final products, and results in the increase in waste product that must be disposed of safely.
• the tubular reactor is preferentially vertically elongated and preferably has-a substantially circular cross-section.
• the purpose of this invention is to provide improved polyvinyl chloride polymerization processes that utilize certain phenothiazine derivatives to reduce reactor, wall fouling or scale deposits, as well as flocculated material during polymerization of vinyl chloride and comonomers.
• U.S. Patent 2,415,252 describes the preparation of phenothia ⁇ zine derivatives by reacting phenothiazine with formaldehyde and an alcohol under conditions that produce a modified phenothiazine that has attached thereto a methylene group and an alkoxy group.
• the compounds and their solutions in oil are said to be useful for pharmaceutical, veterinary and pest-control purposes.
• U.S. Patent 2,528,092 describes the reaction of phenothiazine with formaldehyde and N-dimethylaniline. The resulting compound is useful as an antioxidant for mineral oil lubricants.
• U.S. Patent 4,465,881 describes N,N'-dimers of phenothiazine or a substituted phenothiazine. The compounds result from the linkage of two phenothiazine molecules through their N groups. These dimers are prepared by heating phenothiazine in the presence of an organic peroxide. These dimers are disclosed to be useful to stabilize vinyl aromatic compounds such as styrene and substituted styrenes against undesired polymerization.
• U.S. Patent 4,529,500 discloses the use of the N,N'-dimer of phenothiazine or a substituted phenothiazine to protect hydrocarbon processing equipment against fouling during the processing of hydrocarbons at elevated temperatures.
• U.S. Patent 4,229,510 a polymer material is formed from a substituted phenothiazine wherein the nitrogen group is substituted with an alkyl group. It appears that reaction with formaldehyde occurs between the phenyl groups and formaldehyde. The resulting product has the nitrogen group blocked with the alkyl group of the starting material. The resulting products are reported to have photoconductive properties.
• U.S. Patent No. 4,565,834 describes compounds that have the formula of a dimer or polymer of phenothiazine. The patentees' compositions are useful as stabilizer-containing reactive components for the production of polyurethane foams which have little or no tendency toward core decolorization.
• the purposes of this invention are also accomplished by providing polymerization processes for polymerizing vinyl chloride and co-monomers to polyvinyl chloride and co-polymers which compri ses conducting the polymerization in the presence of a composition having the formul a
• n has an average value of about one to about five, and wherein R is -DL or - ⁇ >
• n has an average value of about one to about five.
• the polymerization processes of the invention include emulsion polymerization, bulk or mass polymerization, suspension polymerization and microsuspension polymerization.
• the invention also includes the process of reacting phenothiazine with selected aldehydes such as acetaldehyde and benzaldehyde.
• the invention further includes the process of reacting a substituted phenothiazine with formaldehyde.
• a suitable substituted phenothiazine is acetylphenothiazine.
• the phenothiazines are reacted with the aldehydes in the presence of a liquid diluent that is a solvent for the phenothiazine, but a non-solvent for the dimer of phenothiazine and an aldehyde and higher oligomers of phenothiazine and an aldehyde.
• reaction processes are generally conducted in the presence of a strong acid catalyst.
• the aldehyde is added slowly to the reaction mixture over the course of the reaction.
• the product can be filtered and dried.
• the invention involves reaction products of the compound phenothiazine which has the formula
• This compound is currently used in animal disease control, in pharmaceutical applications, such as against pinworms in animals.
• the phenothiazine is reacted with an aldehyde.
• the molar ratio of aldehyde to phenothiazine is generally in the range of about 0.1 to less than 1, preferably in the range of about 0.4 to less than 1, and more preferably about 0.5.
• Diluents for the reaction mixture of the invention are liquids that dissolve the phenothiazine, but which are not solvents for the dimer of the phenothiazine and the aldehyde and higher oligomers of the phenothiazine and the aldehyde.
• the dimer and higher oligomers of the phenothiazine are ormed, such dimers and higher oligomers precipitate from the diluent ' and can be removed from the reaction mixture.
• Suitable diluents include non-polar solvents such as tetrahydrofuran (THF), dimethylformamide (DMF), cyclohexanone and dimethylsulfoxide (DMSO).
• non-polar solvents such as tetrahydrofuran (THF), dimethylformamide (DMF), cyclohexanone and dimethylsulfoxide (DMSO).
• Suitable polar diluents include alcohols, preferably those alcohols having one to five carbon atoms, although higher alcohols up to 10 carbons can be used. Suitable alcohols include methanol , ethanol , n-propanol, isopropanol, n-butanol, secondary butanol , isobutanol and tert-butanol .
• polar solvents are preferred, but mixtures of polar and nonpolar solvents are also found to be suitable to perform the function of dissolving the monomer but precipitating the dimer and higher oligomers.
• the weight ratio of non-polar to polar solvent is generally in the range of about 0.1 to 10, preferably about 0.5 to 2, and still more preferably about 1 to 1. It is found that the solubility function is important in determining the structure of the product of the invention. Thus, if too powerful a solvent is employed, the dimer and higher oligomers do not precipitate and too high a molecular weight is achieved. If, on the other hand, the solvent is too poor, the monomer has difficulty dissolving and being available for the reaction with the formaldehyde to form the reaction product.
• the diluent is employed in the reaction mixture such that the phenothiazine is present in an amount from about one or two weight percent up to about 25 weight percent, preferably up to about 10 weight percent of the diluent.
• the reaction product should be sufficiently dilute so that it can be filtered to remove the .solvent from the product.
• Either acidic or alkaline compounds can be employed as catalysts for the reaction.
• acid compounds are preferred, and of these the strong acids are more preferred.
• the preferred compounds include hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid.
• Suitable caustic compounds include sodium hydroxide and other alkali metal hydroxides.
• the aldehyde is slowly added to the mixture of diluent and phenothiazine so that there is an orderly reaction to form the dimer and higher oligomers, and subsequent precipitation of the dimers and oligomers from the reaction mixture.
• the preferred reaction temperature is in the range of room temperature to the reflux temperature of the lowest boiling diluent, preferably about 60 to 80 degrees Celsius.
• the reaction mixture is removed from the reaction vessel and filtered by conventional means. Suitable filter media include paper and cloth, such as nylon cloth.
• the filtered product is dried at a temperature in the range of about room temperature up to the melting point of the composition of the invention, preferably at a temperature of about 50 to 100 degrees Celsius.
• the reaction product of the invention generally comprises a mixture of the following components.
• the reaction product generally has the formula
• R is -CH-, or -® , and wherein n has an average value of about 1 to about 5, preferably 1 to about 2, and more preferably 1 to about 1.5.
• the composition is composed of a mixture of individual compounds of the formula wherein n is an integer from 1 to about 10, preferably from 1 to about 5.
• n has an average value of about 1 to about 5, preferably 1 to about 2, and more preferably 1 to about 1.5.
• the composition is composed of a mixture of individual compounds of the formula wherein n is an integer from 1 to about 10, preferably from 1 to about 5.
• the reaction mixture can be processed to change the relative ratios of the foregoing components.
• the -unreacted monomer can be removed from the reaction mixture by ethanol extraction down to about 0.5 weight percent or less of unreacted monomer.
• the dimer can be separated from the trimer and higher oligomer materials by a series of extractions with suitable solvents.
• the conversion of the phenothiazine to dimer and higher oligomer is generally in the range of about 75 to 90 percent.
• the dimer of the invention or the reaction products including the dimer are utilized as follows in the reduction or elimination of scale and flocculated material in a reaction vessel and components such as an agitator used for the polymerization of vinyl chloride.
• the compositions of the invention are also useful in the polymerization of vinyl chloride withc -olefinically unsaturated comonomers, more specifically, ethylenically unsaturated comonomers in a proportion of up to about 80 mole percent comonomers, more specifically, up to about
• Such comonomers include vinyl acetate, and other ethylenically unsaturated monomers that are well known in the art.
• the dimer alone or together with higher oligomers is dissolved in a suitable solvent such as tetrahydrofuran (THF) in a proportion of about 0.3 to about 1 weight percent.
• THF tetrahydrofuran
• the resulting solutions are then brushed or sprayed on the reactor walls, on the reactor agitator, and inside the reactor head.
• the polymerization reaction mixture is inhibited from forming undesirable scale on the reactor components.
• suitable solvents that can be employed in the application of the solutions to the reactor components include dimethylformamide (DMF), cyclohexanone and dimethylsulfoxide (DMSO).
• composition of the invention can also be added directly to the polymerization reaction mixture, generally in a proportion of about 0.0001 to about 0.01 weight percent solids, preferably about 0.001 weight percent solids based on the weight of vinyl chloride and comonomers.
• the composition of the invention can be added to the polymerization zone as dry solid or in solution in the foregoing solvents.
• the composition can also be added in the wet cake form after filtering, but before drying in the manufacturing process.
• the dimer of the invention or the reaction products including the dimer, are also useful in inhibiting the polymerization of monomers such as vinyl chloride or in shortstopping the polymerization of such monomers.
• the tan powder was soluble in tetrahydrofuran and showed a strong secondary amine band and a 1,2,4-tri-substituted benzene ring band on the infrared curve, indicating that the acetaldehyde has reacted only with the benzene rings.
• a control polymerization was carried out with no coati g on the agitator.
• Example 2 was repeated with diphenylamine used in place of 2-acetyl phenothiazine.
• Example 2 was repeated, using the tertiary amine compound, N-methyl phenothiazine, and formaldehyde.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Polymerisation Methods In General (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Nitrogen- Or Sulfur-Containing Heterocyclic Ring Compounds With Rings Of Six Or More Members (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=26977816

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Citations (1)

Family Cites Families (4)

• 1990
  • 1990-10-17 JP JP2515562A patent/JP3053212B2/ja not_active Expired - Lifetime
  • 1990-10-17 WO PCT/US1990/005829 patent/WO1991006576A1/en not_active Application Discontinuation
  • 1990-10-17 AU AU67159/90A patent/AU6715990A/en not_active Abandoned
  • 1990-10-17 EP EP19900916607 patent/EP0496816A4/en not_active Withdrawn
  • 1990-10-20 CN CN90108604A patent/CN1036400C/zh not_active Expired - Lifetime
• 1991
  • 1991-06-20 NO NO1991912407A patent/NO912407D0/no unknown
• 2000
  • 2000-01-17 JP JP2000007364A patent/JP3305690B2/ja not_active Expired - Fee Related

Patent Citations (1)

Also Published As

Similar Documents

Legal Events