Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L53/00—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L53/02—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers of vinyl-aromatic monomers and conjugated dienes
• • 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
  • C08F297/00—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer
  • C08F297/02—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type
  • C08F297/04—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type polymerising vinyl aromatic monomers and conjugated dienes

Definitions

• This invention relates generally to linear tetrablock copolymer compositions and their use in road-marking applications.
• These tetrablock copolymers contain polystyrene, polyisoprene and polybutadiene components.
• Road-marking compounds prepared from these copolymers typically further contain hydrocarbon resin, fillers and glass beads.
• Block copolymers are generally known in the art and have been used in a variety of applications. There are two basic, distinct block copolymer types: linear and radial. Radial block copolymers contain polymer block branches radiating from a central coupling agent. Such polymers are described in, for example, U.S. Patent No. 5,399,627. This patent describes polymers for use in pressure sensitive adhesive compositions and describes radial block copolymers comprised of polystyrene, polyisoprene, and polybutadiene block segments. Linear block copolymers do not have radiating branches; the block components are arranged sequentially. For example, U.S. Patent No. 5,750,623 describes linear styrene-isoprene-styrene and styrene-butadiene-styrene block copolymers useful in hot-melt adhesives.
• Linear block copolymers are also used to prepare compositions for road or pavement marking.
• Such compositions typically comprise copolymer elastomer and hydrocarbon resin components as well as color and reflective additives such as pigments and glass beads.
• U.S. Patent No. 5,213,439 is directed to pavement marking and describes a dry-blended powder containing linear or radial tri-block copolymers with two poly(vinylaromatic) blocks and a conjugated diene block.
• This copolymer must be ground to a powder before mixing with hydrocarbon resins and other additives. This grinding replaces prolonged melt-blending procedures using expensive high- shear stirring to mix thermoplastic rubbers with hydrocarbon resin.
• We have discovered that certain linear tetrablock copolymer compositions are readily melted and mixed with hydrocarbon resin thus avoiding both powder grinding and high-shear stirring.
• Such copolymers have potential value in road- marking applications in addition to their more typical adhesive applications.
• the present invention relates to a tetrablock copolymer composition
• a tetrablock copolymer composition comprising a linear SISI of SISB block copolymer.
• the block copolymers are of styrene and isoprene and/or butadiene.
• the styrene content of the polymers used in the present invention should be from 10-27 percent by weight, alternatively from 12-20 or 15-18 percent by weight.
• Molecular weights are measured by Gel Permeation Chromatography (GPC), where the GPC system has been appropriately calibrated for example by using standards of similar known-molecular- weight polymer. Accordingly, the present invention selects polymers that enable good melting when mixed in traditional thermoplastic road-marking mixers. Some polymer embodiments have the following properties: an overall styrene content between 10-27 wt%, alternatively between 12-20 wt%. The preferred rubbers are 100% tetrablock.
• the styrenic block copolymers used in some invention embodiments have a molecular weight of from 45,000-250,000. The molecular weights of the various copolymer blocks may be varied. Some embodiments select the styrenic - blocks with a molecular weight of from 4,000-35,000, alternatively, 6,000-20,000 or 8,000-20,000.
• the unsaturated diene blocks should have a molecular weight of from
• Unsaturated diene blocks with molecular weights of 20,000 or above provide a suitably strong polymer. Unsaturated diene blocks with molecular weights of 200,000 or less are suitably processable. Where SISI, SISB, SBSI, or SBSB polymers are used, the molecular weight of the two unsaturated diene blocks can be varied. DETAILED DESCRIPTION
• linear tetrablock copolymers are particularly useful in road-marking compounds due to their flowability and quick melting capability. They can easily be melt mixed with hydrocarbon resins and other additives without powdering or high-shear mixing. Each block may be either polystyrene
• the tetrablock copolymer contains two S blocks plus two B blocks, two I blocks, or one B and one I block, i.e.: S-I-S-I, S-I-S-B, S-B-S-B and S-B-S-I. Each block is present at 10-90 wt% of block copolymer based on the total copolymer weight.
• an S component exists in a tetrablock copolymer at a minimum of 5 wt%, alternatively, a minimum of 10 wt%.
• the S component exists at up to 70 wt%, alternatively up to 60 wt%, up to 40 or up to 30 wt% of the copolymer.
• the weight-average molecular weight of invention tetrablock copolymers varies widely depending on the copolymer's make-up. Generally, the overall peak weight-average molecular weight has a minimum of 10,000, alternatively, a minimum of 50,000, or 100,000. The overall peak weight-average molecular weight maximum is 1,000,000, alternatively not more than 500,000, not more than 300,000, or not more than 200,000.
• the invention linear tetrablock copolymers are "pure" in the sense that they contain no measurable residual triblock or diblock copolymer. But they may contain up to 1% by weight residual triblock and/or diblock copolymer.
• these linear tetrablock copolymers are mixed with a hydrocarbon resin, such as a substantially non-aromatic hydrocarbon resin, or with a rosin ester or a blend of both.
• a hydrocarbon resin such as a substantially non-aromatic hydrocarbon resin, or with a rosin ester or a blend of both.
• substantially non-aromatic means that if there is aromatic hydrocarbon present, it is at a low enough level to function in these copolymer compositions.
• Preferred non-aromatic resins are polymerized from a stream of aliphatic petroleum derivatives in the form of dienes and mono- olefins containing 5 to 6 carbon atoms. At room temperature, these hydrocarbons range from materials that are normally liquid to those that are normally solid at room temperature.
• Commercially available resins such as ESCOREZTM 1102RM (ExxonMobil Chemical), are suitable. Many useful resins have a Ring and Ball softening point (ASTM D 28-96) from 90-110°C, alternatively from 95-105°C, and a melt viscosity at 160°C (ETM-E-31) from 500-3000 mPa sec, alternatively from 1000-2500 mPa sec.
• Suitable hydrocarbon resins are well known and commercially available, e.g. under the trademarks “ESCOREZTM”, “HERCULESTM”, “QUINTONETM”.
• Suitable rosin esters are commercially available, e.g. under the trademarks "BEVILLNETM” and “SYLVATACTM”.
• the relative amounts of tetrablock copolymer and hydrocarbon resin depends on the selected components. Typically, the block copolymer and hydrocarbon resin are present in a weight ratio of from 0.5:99.5 to 20:80, preferably from 2:98 to 15:85.
• Invention road-marking compositions may further contain additives such as pigments, glass beads, fillers, oils, and viscosity modifiers. Titanium dioxide is a particularly useful pigment, and mineral aggregates are particularly useful fillers.
• compositions' individual components may be combined in a number of ways, but the invention copolymers are uniquely suited to simple melt mixing with the hydrocarbon resin and any desired additive.
• the melt-mixing temperature has a minimum of 170°C or 180°C.
• the maximum melt- mixing temperature is 200°C, but melt-mixing temperatures as high as 210°C are not unusual.
• the tetrablock copolymers may be prepared by any suitable polymerization technique. Polymerization systems in which the blocks are produced sequentially are preferred to those in which two or more pre-formed blocks are coupled to each other. The preferred, sequential, polymer development enables greater variation in the molecular weight of the blocks.
• the molecular weights reported here are peak molecular weight as measured by size exclusion chromatography using polystyrene calibration. Commercially available polystyrene standards were used for calibration, and the molecular weights of copolymers corrected according to Runyon et al, Journal of Applied Polymer Science, Vol. 13, Page 359 (1969) and Tung, L. H., Journal of Applied Polymer Science, Vol. 24, Page 953 (1979).
• the melt-mixing temperature has a minimum of 170 °C or 180 °C.
• the maximum melt-mixing temperature is usually 200 °C, but melt- mixing temperatures as high as 210 °C are not unusual.
• Melt flow rate was determined using ASTM D 1238, 200/5.0.
• Comparative Sample 1 is an S-I-S triblock copolymer, VECTORTM 4111 (commercially available from Dexco Polymers).
• Comparative Sample 2 is an S-I-S/S-I triblock/diblock copolymer mix,
• VECTORTM 4113 (commercially available from Dexco Polymers).
• Comparative Sample 3 is an S-I-S/S-I triblock/diblock copolymer mix, VECTORTM 4114 (commercially available from Dexco Polymers).
• Comparative Sample 4 is an S-I-S/S-I triblock/diblock copolymer mix, DPX 559TM, (commercially available from Dexco Polymers) having 15% styrene,
• Comparative Sample 5 is an S-I-S triblock copolymer, DPX 562TM (commercially available from Dexco Polymers). DPX 562TM is a linear SIS with 15% styrene and a Melt Flow Rate (ASTM 1238, 200/5.0) of 25 g/10 min. Comparative Sample 6 is an S-I-S/S-I triblock/diblock copolymer mix,
• DPX 565TM (commercially available from Dexco Polymers). DPX 565TM has the following properties. Molecular weight SIS: 176000 g/mol; Molecular weight SI: 83000 g/mol; Styrene content SIS: 16.1% (by weight); Styrene content SI: 16.1% (by weight); SI content: 54% of the polymer.
• Invention Sample 7 is an S-I-S-I tetrablock copolymer in accordance with this invention made at Dexco Polymers by sequential polymerization. It has the following respective molecular weights, in g/mol: 12400, 60000, 12400, 70000, and styrene content of 16% (by weight).
• Invention Sample 8 is an invention S-I-S-B tetrablock copolymer made at Dexco Polymers by sequential polymerization. It has the following respective molecular weights, in g/mol: 11000, 57000, 11000, 40000, and styrene content of 19% (by weight).
• Comparative Sample 9 is an S-I-S/S-I triblock/diblock copolymer mix, TR 1107TM (commercially available from Shell Oil Company).
• Comparative Sample 10 is an S-I-S/S-I triblock/diblock copolymer mix, KRATONTM D 601 P (commercially available from Shell Oil Company).
• Comparative Sample 11 is an S-I-S/S-I triblock/diblock copolymer mix, KRATONTM D 113 (commercially available from Shell Oil Company).
• Comparative Sample 12 is an S-I-S/S-I triblock/diblock copolymer mix, QUINTACTM 3433 (commercially available from Nippon Zeon).

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• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Paints Or Removers (AREA)
• Graft Or Block Polymers (AREA)

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• 2001
  • 2001-06-25 WO PCT/US2001/020289 patent/WO2002000787A1/en active Application Filing
  • 2001-06-25 BR BR0112354-8A patent/BR0112354A/pt not_active Application Discontinuation
  • 2001-06-25 EP EP01950485A patent/EP1299475A1/en not_active Withdrawn
  • 2001-06-25 MX MXPA02012668A patent/MXPA02012668A/es active IP Right Grant
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