Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C7/00—Purification; Separation; Use of additives
  • C07C7/20—Use of additives, e.g. for stabilisation
• • 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
  • C08F12/00—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 an aromatic carbocyclic ring
  • C08F12/02—Monomers containing only one unsaturated aliphatic radical
  • C08F12/04—Monomers containing only one unsaturated aliphatic radical containing one ring
  • C08F12/06—Hydrocarbons
  • C08F12/08—Styrene

Definitions

• the invention pertains to methods and compositions for inhibiting the undesired polymerization of vinyl aromatic monomers, such as styrene monomer, during processes such as monomer preparation, and purification, and during storage and shipment of products containing such monomers.
• vinyl aromatic monomers such as styrene monomer
• Polystyrene is a thermoplastic with many desirable characteristics. It is clear, transparent, readily colored and easily fabricated.
• the family of styrene polymers includes polystyrene itself, copolymers of styrene with other vinyl monomers, polymers of derivatives of styrene and mixtures of polystyrene and styrene-containing copolymers with elastomers.
• ABS acrylonitrile, butadiene-styrene resins
• styrene plastics are commonly used for packaging, including foams and films, coatings, in appliance fabrication, for housewares and toys, lighting fixtures and in construction materials.
• a method for inhibiting the polymerization of a vinyl aromatic monomer such as styrene monomer, i.e., ethylbenzene.
• the method comprises adding an effective polymerization inhibiting amount of a combined treatment to the monomer medium.
• the combined treatment comprises (A) a quinone methide derivative and (B) a phenol compound. From about 1-10,000 ppm of (A) and (B) collectively is brought into contact with the requisite vinyl aromatic monomer based on 1 million parts of the monomer.
• the method may, in other aspects of the invention, comprise the step of heating the monomer and, in another aspect of the invention, the monomer may be distilled to remove impurities therefrom.
• a vinyl aromatic monomer anti -polymerization composition which comprises a liquid carrier and dissolved or dispersed therein (A) a quinone methide derivative and (B) a phenol compound.
• the quinone methide derivative is 2,6-di-tert-butyl-4- benzylidene-cyclohexa-2 ,5 -dienone.
• the phenol compound (B) is 2,6-di-t- butylphenol.
• a liquid carrier such as a non-polar organic solvent is provided with the combined treatment (A) and (B) dissolved or dispersed therein.
• both a quinone methide derivative A) and a phenol compound B) are conjointly utilized to inhibit polymerization of a vinyl aromatic monomer such as styrene.
• the quinone methide derivatives generally have the formula:
• Ri and R 2 are independently H, C 4 to C 18 alkyl; C 5 to C 12 cycloalkyl; or C 7 to C 15 phenylalkyl.
• Ri and R 2 are tert-butyl, tert-amyl, tert-octyl, cyclohexyl, a- methylbenzyl or ⁇ , ⁇ -dimethylbenzyl; with tert-butyl, tert-amyl or tert-octyl most preferred.
• R 3 is preferably aryl, or aryl substituted with Ci to C 6 alkyl, alkoxy, hydroxy, nitro, amino, carboxy, or mixtures thereof.
• the quinone methide derivative is 2,6-di-tert-butyl-4-benzylidene- cyclohexa-2,5-dienone.
• phenol compounds B that may be utilized generally have the formula:
• R 4 and R5 may be the same or different and are chosen from C 1 -C20 alkyl, C- 1 -C30 alkaryl and substituted C 1 -C30 alkaryl
• R 6 when present, is selected from C 1 -C20 alkyl, thiophenol, substituted thiophenol, C1-C40 alkanoic acid ester, C1-C30 alkaryl, substituted C1-C30 alkaryl, Ci-C 6 alkylamino, Ci-C 6 alkoxy, amine, polynuclear aryl and substituted polynuclear aryl.
• the preferred phenol B) compound is 2,6-di-t-butylphenol.
• exemplary phenols include 2,6-dipropylphenol, 2,6-diethylphenol and 2,6-dimethylphenol.
• compositions of the present invention are effective at inhibiting
• processing conditions include but are not limited to preparation, purification, distillation and vacuum distillation processes.
• Styrene for example, is typically processed at temperatures between 95° and 125° C.
• the compositions of the present invention are effective at inhibiting the polymerization of styrene over this range of temperatures.
• the vinyl aromatic monomers that are treated by the compositions of the present invention include but are not limited to styrene, bromostyrene, divinylbenzene, and a- methylstyrene.
• the compositions of the present invention are particularly efficacious at inhibiting the polymerization of styrene monomer.
• the total amount of quinone methide derivative A) and phenolic compound B) used in the methods of the present invention is that amount which is sufficient to inhibit polymerization of vinyl aromatic monomers. This amount will vary according to the conditions under which the vinyl aromatic monomer is being processed, contaminants in the system and the temperature of the system. At higher processing temperatures and higher monomer
• the term "effective inhibiting amount” is that amount which is effective at inhibiting vinyl aromatic monomer polymerization.
• this amount ranges from about 1 part to about 10,000 parts of quinone methide derivative and phenolic compound, collectively, per 1 million parts of monomer. Most preferably, this amount will range from about 1 to 1,000 parts per million parts monomer.
• the weight ratio of quinone methide derivative to phenolic compound will generally range from about 90: 10 to about 10:90. Most preferred is a weight ratio of about 70:30.
• compositions of the present invention can be introduced into the vinyl aromatic monomer by any conventional method at any point of the processing system, either as separate and individual ingredients or as a combination of ingredients.
• compositions of the present invention may be added to the vinyl aromatic monomer as either a dispersion or as a solution using a suitable liquid carrier or solvent.
• a suitable liquid carrier or solvent Any solvent that is compatible with the individual ingredients of the composition and the vinyl aromatic monomer to be treated may be employed. It is often desirable to dissolve the inhibitors in the monomer to which the inhibitor is being added to avoid introducing additional impurities in the monomer.
• Exemplary liquid carriers include non-polar organic solvents, such as heavy aromatic naphtha and xylene.
• the method of the present invention can control the fouling of processing equipment, such as the equipment used in separation and purification processes of styrene monomer, which is due to or caused by the polymerization of the monomer.
• the instant invention may be used as both a process inhibitor, which is employed during preparation and processing (e.g., employing heat) of the styrene monomer (i.e., ethylbenzene), and as a product inhibitor, which is combined with the styrene monomer in order to inhibit polymerization during storage and handling.
• the flask was purged with Argon for 10 minutes. The flask was then immersed into an oil-bath thermostatically controlled at 115-120 °C and heated with purging Ar continuously. Once the temperature reached 115 °C, the stop clock was started and this time was considered as time zero. About 5 ml of the sample was removed from the flask at varying time intervals for up to 4 hours and measured precisely before pouring into about 40 ml methanol to precipitate out the styrene polymer. The precipitated polystyrene was filtered with a gas membrane filter that was pre-weighed before use. The polymer was dried at 100 °C and weighed.
• Table I Amount of polystyrene formation at 115-120 °C as a function of time for a resultant retarder dosage of about 600 ppm with different ratios of 2,6-tertiary butyl phenol (DTBP) and QM.
• DTBP 2,6-tertiary butyl phenol

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Water Supply & Treatment (AREA)
• Analytical Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Polymerisation Methods In General (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (2)

Family

ID=44626629

Family Applications (1)

Country Status (14)

Cited By (1)

Families Citing this family (6)

Citations (1)

Family Cites Families (19)

• 2010
  • 2010-06-03 US US12/793,226 patent/US8298440B2/en active Active
• 2011
  • 2011-05-10 KR KR1020127031218A patent/KR101877069B1/ko active Active
  • 2011-05-10 MY MYPI2012004898A patent/MY158328A/en unknown
  • 2011-05-10 MX MX2012014075A patent/MX2012014075A/es not_active Application Discontinuation
  • 2011-05-10 EP EP11721893.3A patent/EP2576718B1/en active Active
  • 2011-05-10 BR BR112012028981-0A patent/BR112012028981B1/pt active IP Right Grant
  • 2011-05-10 ES ES11721893.3T patent/ES2621605T3/es active Active
  • 2011-05-10 SG SG2012086864A patent/SG185758A1/en unknown
  • 2011-05-10 CA CA2800495A patent/CA2800495C/en active Active
  • 2011-05-10 PL PL11721893T patent/PL2576718T3/pl unknown
  • 2011-05-10 JP JP2013513183A patent/JP5683692B2/ja active Active
  • 2011-05-10 WO PCT/US2011/035934 patent/WO2011152961A2/en not_active Ceased
  • 2011-05-30 TW TW100118905A patent/TWI501947B/zh active
  • 2011-06-01 AR ARP110101886A patent/AR081555A1/es active IP Right Grant
• 2012
  • 2012-09-27 US US13/628,536 patent/US20130030225A1/en not_active Abandoned

Patent Citations (1)

Also Published As

Similar Documents

Legal Events