Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/10—Esters; Ether-esters
  • C08K5/12—Esters; Ether-esters of cyclic polycarboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or 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; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/04—Homopolymers or copolymers of styrene
  • C08L25/08—Copolymers of styrene
  • C08L25/12—Copolymers of styrene with unsaturated nitriles

Definitions

• Copolymers of styrene and acrylonitrile and methods for their preparation are well known in the art.
• the copolymers possess good resistance to organic solvents and are highly transparent.
• This is accomplished by use of a plasticizer.
• epoxidized soybean oil as a suitable plasticizer for styrene/acrylonitrile copolymers.
• resins containing epoxidized soybean oil have a tendency to discolor, especially when exposed to elevated temperatures for extended time periods.
• plasticizers such as alkyl phthalates have failed in such severe environments due to "sweating" or deposition of the plasticizer onto the mold surfaces.
• the primary purpose of this invention is to provide methods of improving the melt flow rate and other properties of copolymers of acrylonitrile and styrene.
• a further purpose of this invention is to provide a means of plasticizing copolymers of acrylonitrile and styrene without sacrifice of the desirable transparency or color properties of the copolymer.
• a further purpose of the invention is to prepare a new and more useful composition of matter that may be utilized at extremes of temperature without encountering problems of "sweat out", i.e., loss of plasticizer and condensation thereof on cool surfaces of molding equipment or injection molded parts.
• the preferred plasticizers for the practice of this invention are the acid triesters having the structural formula:
• Ar is an aromatic radical of up to 20 carbons
• R is an alkyl or aryl radical having up to 20 carbon atoms.
• Preferred triesters are linear Cg_2o alkyl triesters of trimellitic acid.
• Particularly preferred esters are tridecyl trimellitate, tridodecyl trimellitate, tri-n-octyl trimellitate, mixed C 810 linear alkyl trimellitates, etc.
• the straight chain or linear alkyl triesters are particularly preferred due to the improved color stability. Additive discoloration upon prolonged heating is believed to be due to the greater instability of tertiary hydrogen proton compared to a secondary hydrogen moiety.
• the plasticized copolymers are prepared by mixing the desired plasticizer and copolymer in any of the conventional mixing machines, for example, roll mills, Banbury type mixers, extruders, etc., which may be heated to soften the copolymers.
• the plasticizer may also be coated onto the surface of polymer granules to be later melted and incorporated into the polymer or incorporated into the polymerization mixture and thus into the polymer prior to devolitalization and granulation.
• the quantity of plasticizer used will depend upon the ultimate use of the composition.
• a plasticizing amount of the aromatic acid triester i.e., sufficient amount to improve the polymer's properties, is employed.
• Preferred amounts of plasticizer are from 0.1 to 5 percent, more preferable 0.5 to 2.5 percent by weight. The optimum proportion of triester may readily be determined by preparing test samples and measuring the melt flow rate enhancement, rheology, and other desired physical properties of the resulting resin.
• Additional additives such as colorants, UV stabilizers, reinforcing aids, blowing agents, fibers, fillers, etc. may be included in the copolymeric compositions of the present invention. Further details of the preparation and evaluation of the new products are set forth with respect to the following specific examples:
• a recirculated coil reactor was employed to prepare catalytic styrene acrylonitrile containing approximately 25 percent by weight acrylonitrile and molecular weight (Mw) of about 150,000. (Actual molecular weights of samples tested are provided in Table I.)
• trimellitate esters gave slightly improved melt flow rate compared to the use of epoxidized soybean oil. Additionally, the decrease in flexural strength for the trimellitate esters was not as great as with the phthalate diester plasticizers. When compared with the phthalate diesters for mold sweating problems, the trimellitate esters were shown to possess improved properties.

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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)
• Compositions Of Macromolecular Compounds (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Publications (2)

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• 1990
  • 1990-09-19 CA CA002044176A patent/CA2044176A1/en not_active Abandoned
  • 1990-09-19 AU AU64473/90A patent/AU6447390A/en not_active Abandoned
  • 1990-09-19 KR KR1019910700734A patent/KR920701346A/ko not_active Withdrawn
  • 1990-09-19 EP EP19900914568 patent/EP0453524A4/en not_active Withdrawn
  • 1990-09-19 WO PCT/US1990/005333 patent/WO1991007459A1/en not_active Ceased
  • 1990-09-19 JP JP2513792A patent/JPH04503083A/ja active Pending

Patent Citations (1)

Non-Patent Citations (2)

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