US20200199334A1 - Dual Composition Block Copolymers - Google Patents

Dual Composition Block Copolymers Download PDF

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Publication number
US20200199334A1
US20200199334A1 US16/595,913 US201916595913A US2020199334A1 US 20200199334 A1 US20200199334 A1 US 20200199334A1 US 201916595913 A US201916595913 A US 201916595913A US 2020199334 A1 US2020199334 A1 US 2020199334A1
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Prior art keywords
block copolymer
monovinyl aromatic
dual composition
molecular weight
conjugated diene
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US16/595,913
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English (en)
Inventor
Daniel Abraham Elizarrarás Maya
Abel Zúñiga Calles
Gabriel Hernández Zamora
José Luis García Vidales
Jesús Eduardo Ibarra Rodríguez
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Dynasol Elastomeros SA de CV
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Dynasol Elastomeros SA de CV
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Priority to US16/595,913 priority Critical patent/US20200199334A1/en
Assigned to DYNASOL ELASTÓMEROS, S.A. DE C.V. reassignment DYNASOL ELASTÓMEROS, S.A. DE C.V. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Elizarrarás Maya, Daniel Abraham, García Vidales, José Luis, HERNÁNDEZ ZAMORA, Gabriel, Ibarra Rodríguez, Jesús Eduardo, Zúñiga Calles, Abel
Priority to EP23206980.7A priority patent/EP4324880A3/en
Priority to BR112021006532-6A priority patent/BR112021006532B1/pt
Priority to ES19899386T priority patent/ES2966215T3/es
Priority to CA3115790A priority patent/CA3115790C/en
Priority to CN201980004574.7A priority patent/CN112996826B/zh
Priority to PL19899386.7T priority patent/PL3853274T3/pl
Priority to PCT/IB2019/001434 priority patent/WO2020128635A2/en
Priority to KR1020217022867A priority patent/KR102655500B1/ko
Priority to JP2021523842A priority patent/JP2022506453A/ja
Priority to MX2021004587A priority patent/MX2021004587A/es
Priority to CN202310295514.3A priority patent/CN116217844A/zh
Priority to EP19899386.7A priority patent/EP3853274B1/en
Priority to KR1020247010699A priority patent/KR20240046309A/ko
Priority to TW108146769A priority patent/TWI734310B/zh
Publication of US20200199334A1 publication Critical patent/US20200199334A1/en
Priority to JP2023029610A priority patent/JP2023076434A/ja
Abandoned legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
    • C08L9/06—Copolymers with styrene
    • 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
    • C08F297/044—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 using a coupling agent
    • 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
    • C08F297/046—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 polymerising vinyl aromatic monomers and isoprene, optionally with other conjugated dienes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
    • C08J9/06—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent
    • C08J9/10—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent developing nitrogen, the blowing agent being a compound containing a nitrogen-to-nitrogen bond
    • C08J9/102—Azo-compounds
    • C08J9/103—Azodicarbonamide
    • 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
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J153/00—Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers
    • C09J153/02—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
    • C08F297/023—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 using a coupling agent
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2201/00—Foams characterised by the foaming process
    • C08J2201/02—Foams characterised by the foaming process characterised by mechanical pre- or post-treatments
    • C08J2201/026—Crosslinking before of after foaming
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2203/00—Foams characterized by the expanding agent
    • C08J2203/04—N2 releasing, ex azodicarbonamide or nitroso compound
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2205/00—Foams characterised by their properties
    • C08J2205/04—Foams characterised by their properties characterised by the foam pores
    • C08J2205/044—Micropores, i.e. average diameter being between 0,1 micrometer and 0,1 millimeter
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2353/00—Characterised by the use of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers
    • C08J2353/02—Characterised by the use of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; 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
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
    • C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure

Definitions

  • This present invention is directed to dual composition block copolymers of conjugated diene and monovinyl aromatic monomers and more particularly to microcellular crosslinked rubber compounds comprising dual composition block copolymers.
  • the novel dual composition block copolymers of the invention can be used to produce microcellular crosslinked rubber compounds with closed cells of homogeneous size, without blistering defects, with improvements in softness and higher resilience.
  • Microcellular rubber compounds have widespread application in the manufacture of a variety of products such as shoe soles, sandals, cushioning pads, floating articles, sound dampening sheets, vibration dampening materials, shock absorbing protectors, sealing applications, etc. Moreover, these materials have great acceptance in the market because of their lightweight and cost effective attributes.
  • closed cells are formed by expansion of a chemical or physical blowing agent under the influence of heat, or combined heat and decompression at typical temperature and pressure for vulcanizing compounding.
  • Crosslinking of the microcellular rubber compounds adds improved and long lasting mechanical performance. Rubber elasticity during foaming, which in most processes is enhanced by partial crosslinking prior or simultaneous to foaming stage, is important to preserve closed cell structure. In the time elapsed between end of expansion and optimum crosslinking attainment, foam rubber compounds tend to shrink.
  • Block copolymers of conjugated diene and monovinyl aromatic monomers have been used in crosslinked microcellular rubber compositions to avoid this shrinkage defect.
  • GB 1,249,220 discloses un-crosslinked elastic foams based on block copolymers, with block configuration of the form (B-S) n , or (B-S) n B, or (S-B) m , wherein B represents substantially a 1-3,butadiene polymer, S represents substantially a styrene polymer, n is an integer ranging from 2 to 10 and m is an integer ranging from 1 to 10.
  • the compositions also include polystyrene homopolymer. Nevertheless, the compositions are disadvantageous, since they include chloro-hydrofluorocarbons as blowing agents, which are harmful to the environment, and exhibit quite large cell size of 0.6 to 1.1 mm.
  • EP 0,323,653 A1 discloses crosslinked rubber foam compositions comprising block copolymers of monovinyl aromatic and conjugated diene monomers with the general formula (A-E) n A, (A-E) n or ((A-E) n ) m X, wherein n ranges from 1 to 4, m ranges from 2 to 8, A represents a monovinyl aromatic polymer block, E represents a conjugated diene polymer block and/or selectively hydrogenated product thereof, and X represents a coupling agent residue.
  • the compositions also include other rubbers, such as natural rubber, diene type synthetic rubber and non-diene synthetic rubber.
  • EP 2,546,291 discloses crosslinked rubber foam compositions comprising a block copolymer comprising vinyl aromatic monomer units and conjugated diene monomer units and/or a block copolymer comprising vinyl aromatic monomer units, conjugated diene monomer units and alkylene monomer units.
  • the composition also includes an olefin-based copolymer (like polyethylene, ethylene-1-butene copolymers, ethylene-octene copolymers, etc.), and optionally an ethylene-based copolymer having an unsaturated group, as EPDM.
  • the preferred block configurations have end blocks rich in vinyl aromatic repeat units and elastomeric repeat unit mid-blocks.
  • WO 2008/083451 A1 discloses rubber vulcanized foam compounds containing block copolymers with molecular configuration consisting of polystyrene end-blocks and elastomeric mid-blocks; the elastomeric mid-blocks being butadiene, isoprene, ethylene, butylene or propylene based.
  • This compounds additionally incorporate styrene-butadiene random copolymers with high and/or mean bound styrene content, as well as ethylene-propylene copolymer (EPR) or ethylene-propylene-diene terpolymer (EPDM).
  • EPR ethylene-propylene copolymer
  • EPDM ethylene-propylene-diene terpolymer
  • Compositions disclosed in EP 0,323,653 A1, EP 2,546,291 and WO 2008/083451 A1 comprise block copolymers with end-blocks rich in vinyl aromatic repeat units surrounding mid-blocks rich in conjugated diene repeat units (or their hydrogenated products). Therefore, all of them have the disadvantage of requiring high compounding temperatures. This is because end-blocks rich in vinyl aromatic repeat units of the block copolymers therein disclosed, form an intermolecular physical network that softens adequately as to flow only above 120° C. This high operating compounding temperature may cause premature decomposition of the chemical blowing agent and/or premature crosslinking onset. This is particularly restrictive when compounding is performed in batch mixers, such as in a Banbury.
  • GB 1,111,250 discloses crosslinked microcellular rubber foam compositions comprising tapered di-block copolymers of conjugated diene and vinyl aromatic monomers.
  • the tapered di-block copolymers disclosed therein are produced in a batch anionic solution polymerization process.
  • the compositions also include random copolymers of conjugated diene and vinyl aromatic monomers, either obtained by anionic solution polymerization or by free radical emulsion polymerization.
  • U.S. Pat. No. 4,003,860 discloses crosslinked microcellular rubber foam compositions comprising tapered di-block copolymers of conjugated diene and monovinyl aromatic monomers.
  • the tapered di-block copolymers disclosed therein are produced in a batch anionic polymerization process.
  • the compositions also include an ethylene/vinyl acetate copolymer.
  • BRPI 0601080-6 A discloses formulations of vulcanized microporous rubber compounds including a block copolymer of styrene and butadiene as the main component. A minor amount of a resin with 40 to 80% of styrene content is included to add hardness to the formulation. The formulation is told to be advantageous for the molding of microporous or microcellular sandal soles. This patent lacks a description of the molecular configuration of the block copolymer and information about its composition range.
  • EP 0674578 B1 U.S. Pat. No. 8,772,414 B2 and US 2015/0259491 A1 show various polymeric foaming compositions where the polymers employed have preferred Tan delta values (the ratio of loss modulus to storage modulus, also known as dissipation factor) slightly below 1, in the melt state, for appropriate closed-cell foaming.
  • Tan delta values the ratio of loss modulus to storage modulus, also known as dissipation factor
  • Microcellular crosslinked rubber compounds comprising tapered block copolymers of butadiene and styrene produced by anionic solution polymerization in continuous reactor process, are known to have a good balance of shrinkage and surface aesthetics, as well as adequate processability in batch compounding equipment. Nevertheless, they still confer hardness and low resilience to microcellular crosslinked rubber compounds. Moreover, the continuous anionic polymerization process lacks the flexibility of a batch process to switch polymerization recipes to get different rubber grades without expending off-grade transition production.
  • the present invention provides novel dual composition block copolymers made from monovinyl aromatic and conjugated diene monomers by an alkyllithium initiated solution polymerization.
  • the dual composition block copolymers of the invention comprise at least two kinds of block copolymer molecules that differ in repeat unit composition, molecular weight and block arrangement structure. Each kind of block copolymer molecule can be distinguished as a peak in the molecular weight distribution of the novel dual composition block copolymer.
  • the invention also provides processes to obtain novel dual composition block copolymers in a batch polymerization reactor.
  • the invention also provides compositions to produce crosslinked microcellular rubber compounds comprising a novel dual composition block copolymer, among other typical ingredients for this class of compounds.
  • compositions of the invention enable to accomplish the compounding stage of crosslinked microcellular rubber production in internal batch mixers, such as a Banbury, at reduced temperature, which is beneficial to avoid premature expansion of the chemical blowing agent and to avoid premature crosslinking problems.
  • the compositions of the invention also provide the advantage of negligible shrinking of the microcellular compound during the crosslinking stage. Shaped articles produced with the compositions of the invention exhibit excellent surface appearance, absent of blisters, high softness and high resilience.
  • the invention also provides hot-melt pressure sensitive adhesive formulations comprising a novel dual composition block copolymer, among other typical ingredients for this class of adhesives. It has been un-expectedly found that hot-melt pressure sensitive adhesive comprising this novel dual composition block copolymers have improved tack and service temperature range.
  • FIG. 1 shows the molecular weight distribution of dual composition block copolymers of Examples 4 and 13 compared to the state of the art block copolymers of Comparative Example C-2 and Buna BL30-4548.
  • the present invention provides novel dual composition block copolymers made from monovinyl aromatic and conjugated diene monomers, comprising two types of block copolymer molecules C and U.
  • the dual composition block copolymers of the invention have a molecular weight distribution with at least two distinguishable fractions, each with a peak in the molecular distribution, as obtained by gel permeation chromatography technique, using a 3-column set, employing a differential refractive index detector, and relying on universal calibration molecular weight curve referred to polystyrene standards (GPC-RI). Adjacent fractions are delimited from each other at local minimums in the molecular weight distribution curve.
  • Block copolymer C is constituted by the fraction with the peak of highest molecular weight in the molecular weight distribution, and block copolymer U constitutes the remainder of the molecular weight distribution.
  • the dual composition block copolymers of the invention have an amount of block copolymer C, quantified by integration of the fraction with the peak at highest molecular weight relative to the whole dual composition block copolymer molecular weight distribution obtained by GPC-RI, from 20% to 80%, more preferably from 30% to 60%, and most preferably from 35% to 45%.
  • the dual composition block copolymers of the invention have an amount of block copolymer U, quantified by the integration of the rest of the molecular weight distribution obtained by GPC-RI relative to the whole dual composition block copolymer molecular weight distribution, from 80% to 20%, more preferably from 70% to 40%, and most preferably from 65 to 55%.
  • the dual composition block copolymers of the invention have a total monovinyl aromatic repeat unit content, % A t , from 20% to 50% on a weight percent basis, as determined by proton NMR analysis.
  • Dual composition block copolymers of the invention have a characteristic monovinyl aromatic repeat unit blockiness degree, as determined by proton NMR analysis. Monovinyl aromatic repeat unit blockiness degree is quantified as the mole percent of monovinyl aromatic repeat units in the block copolymer that are not covalently bonded to conjugated diene repeat units, on a total monovinyl aromatic repeat unit basis.
  • the dual composition block copolymers of the invention have a monovinyl aromatic repeat unit blockiness degree from about 77 mole % to about 100 mole %, more preferably from about 81 mole % to about 100 mole %, and most preferably from about 85 mole % to about 100 mole %, on a total monovinyl aromatic repeat unit basis.
  • a distinctive feature of the dual composition block copolymers of the invention is that the monovinyl aromatic repeat unit content in block copolymer U is higher than the monovinyl aromatic repeat unit content in block copolymer C.
  • the monovinyl aromatic repeat unit weight percent content in the block copolymer U, % A U , the monovinyl aromatic repeat unit weight percent content or block copolymer C, % A C , and the monovinyl aromatic repeat unit weight percent compositional difference between block copolymer fractions U and C, % CD, are calculated as follows:
  • % C uv is the percent amount of the fraction with the peak of highest molecular weight, which corresponds to block copolymer C, relative to the whole molecular weight distribution of the dual block copolymer of the invention obtained by GPC technique with a 3-column set, employing UV absorbance detector at a wavelength of 261 nm and relying on universal calibration molecular weight curve referred to polystyrene standards (GPC-UV);
  • GPC-UV polystyrene standards
  • % A t is the total monovinyl aromatic content of the whole dual composition block copolymer of the invention on a weight basis, obtained by proton NMR analysis;
  • % C ri is the percent amount of the fraction with the peak of highest molecular weight, which corresponds to block copolymer C, relative to the whole molecular weight distribution of the dual block copolymer of the invention, as obtained by gel permeation chromatography technique using a 3-column set, employing differential refractive index detector,
  • the dual composition block copolymers of the invention exhibit a monovinyl aromatic repeat unit weight percent compositional difference between block copolymer fractions U and C, % CD, of at least 10%, preferably of at least 15%, and most preferably of at least 20%.
  • Tan delta also known as the dissipation factor, which is defined as the ratio of loss modulus to storage modulus, is well known in the art as a very appropriate indicator of the balance between the ability to flow and melt strength, and therefore of foaming capability for a variety of polymeric materials.
  • the dual composition block copolymers of the present invention have a characteristic viscoelastic behavior that makes them useful for foaming purposes. In their un-crosslinked condition, dual composition copolymers of the present invention exhibit tan delta values slightly below 1 over a wide range of shear rate and processing temperatures.
  • the dual composition block copolymers of the invention exhibit maximum Tan delta values, when performing a frequency sweep test from 0.25 rad/s to 200 rad/s at 100° C., from 0.74 to 0.95, more preferably from 0.74 to 0.88, and most preferably from 0.74 to 0.81.
  • the dual composition block copolymer of the invention has a Mooney viscosity (ML 1+4 at 100° C.) from 25 to 90, preferably from 30 to 60, and more preferably from 35 to 55.
  • the dual composition block copolymer of the invention has a complex shear dynamic viscosity, evaluated at a strain of 13.95%, at an oscillation frequency of 0.99 rad/s, and a temperature of 100° C., from 50000 Pa-s to 360000 Pa-s. In one embodiment, the dual composition block copolymer of the invention has a complex dynamic viscosity, evaluated at 100 rad/s at 100° C., from 3600 Pa-s to 12000 Pa-s.
  • the dual composition block copolymer of the invention comprises a block copolymer C and a block copolymer U, where
  • block copolymer C has the general formula:
  • block copolymer U has the general formula:
  • D is a polymer block made from at least a conjugated diene monomer and at least a monovinyl aromatic monomer, where conjugated diene repeat units are in greater molar amount than monovinyl aromatic repeat units along the whole polymer block length;
  • (D/A) is a polymer block made from at least a conjugated diene monomer and at least a monovinyl aromatic monomer, where the polymer block end opposite to A 1 or A 2 is predominantly composed of conjugated diene repeat units and that gradually changes its composition along its length until it becomes substantially composed of monovinyl aromatic repeat units towards its end adjacent to A 1 or A 2 ;
  • a 1 and A 2 are polymer blocks made from monovinyl aromatic monomer only;
  • polymer block A 2 has a greater molecular weight than polymer block A 1 ;
  • X is the residue of a coupling agent
  • n is an integer with a value from 2 to 30;
  • Coupled block copolymer molecules of formula [D-(D/A)-A 1 ] n -X account for from about 20 wt % to about 80 wt % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI;
  • uncoupled block copolymer molecules of formula D-(D/A)-A 2 account for from about 80 wt % to about 20 wt % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI;
  • uncoupled block copolymer molecules of formula D-(D/A)-A 1 account for from about 0 wt. % to about 20 wt. % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI.
  • the dual composition block copolymer of the invention comprises a block copolymer C and a block copolymer U, where:
  • block copolymer C has the general formula:
  • block copolymer U has the general formula:
  • B is a polymer block made from one or more conjugated diene monomers only;
  • (B/A) is a polymer block made from at least a conjugated diene monomer and at least a monovinyl aromatic monomer, where the conjugated diene and monovinyl aromatic repeat units are randomly arranged along the polymer block;
  • a 1 and A 2 are polymer blocks made from monovinyl aromatic monomer only, where polymer block A 2 has greater molecular weight than polymer block A 1 ;
  • X is the residue of a coupling agent
  • n is an integer with a value from 2 to 30;
  • Coupled block copolymer molecules of formula [B-(B/A)-A 1 ] n -X account for from about 20 wt % to about 80 wt % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI;
  • uncoupled block copolymer molecules of formula B-(B/A)-A 2 account for from about 80 wt % to about 20 wt % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI;
  • uncoupled block copolymer molecules of formula B-(B/A)-A 1 account for from about 0 wt. % to about 20 wt. % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI.
  • the dual composition block copolymer of the invention comprises a block copolymer C and a block copolymer U, where:
  • block copolymer C has the general formula
  • block copolymer U has the general formula
  • B is a polymer block made from one or more conjugated diene monomers only;
  • a 1 and A 2 are polymer blocks made from monovinyl aromatic monomer only;
  • polymer block A 2 has a greater molecular weight than polymer block A 1 ;
  • X is the residue of a coupling agent
  • n is an integer with a value from 2 to 30;
  • Coupled block copolymer molecules of formula [B-A 1 ] n -X account for from about 20 wt % to about 80 wt % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI;
  • uncoupled block copolymer molecules of formula B-A 2 account for from about 80 wt % to about 20 wt % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI;
  • uncoupled block copolymer molecules of formula B-A 1 account for from about 0 wt. % to about 20 wt. % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI.
  • the dual composition block copolymer of the invention comprises a block copolymer C and a block copolymer U, where:
  • block copolymer C has the general formula:
  • block copolymer U has the general formula:
  • (B/A) is a polymer block made from at least a conjugated diene monomer and at least a monovinyl aromatic monomer, where conjugated diene and monovinyl aromatic repeat units are randomly arranged along polymer block;
  • a 1 and A 2 are polymer blocks made from monovinyl aromatic monomer only, where polymer block A 2 has a greater molecular weight than polymer block A 1 ;
  • X is the residue of a coupling agent
  • n is an integer with a value from 2 to 30;
  • Coupled block copolymer molecules of formula [(B/A)-A 1 ] n -X account for from about 20 wt % to about 80 wt % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI;
  • uncoupled block copolymer molecules of formula (B/A)-A 2 account for from about 80 wt % to about 20 wt % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI;
  • uncoupled block copolymer molecules of formula (B/A)-A 1 account for from about 0 wt. % to about 20 wt. % of the molecular weight distribution of the dual composition block copolymer, as determined by GPC-RI.
  • Another aspect of the invention provides processes for making novel dual composition block copolymers in a batch reactor, comprising: reacting at least one conjugated diene monomer and one monovinyl aromatic monomer under anionic polymerization conditions, and forming a dual composition block copolymer, comprising two types of block copolymer molecules C and U.
  • a preferred embodiment of the present invention is a process for producing a novel dual composition block copolymer in a batch reactor, comprising:
  • C is a block copolymer with general formula [D-(D/A)-A 1 ] n X;
  • U is a block copolymer with general formula D-(D/A)-A 2 ;
  • D is a polymer block made from conjugated diene and monovinyl aromatic monomers, with conjugated diene repeat units being in predominant molar amount;
  • (D/A) is a polymer block that is richer in conjugated diene repeat units towards its end adjacent to D block and that gradually changes its composition until it becomes substantially rich in monovinyl aromatic repeat units towards its opposite end;
  • a 1 and A 2 are polymer blocks comprising monovinyl aromatic repeat units only;
  • polymer block A 2 has greater molecular weight than polymer block A 1 ;
  • X is the residue of a coupling agent
  • n is an integer that spans from 2 to about 30, depending on the coupling agent employed.
  • block copolymer C has greater molecular weight and lower monovinyl aromatic repeat unit content than block copolymer U.
  • An additional embodiment of the present invention is a process for producing a novel dual composition block copolymer in a batch reactor, comprising: adding hydrocarbon solvent, at least a monovinyl aromatic monomer and at least a conjugated diene monomer to a reactor, in any order; adding monofunctional organolithium initiator compound to the reactor and anionically polymerizing the monomer mixture to full conversion to form a block copolymer anion of formula D-(D/A)-A 1 ( ⁇ ) ; adding to the reactor a coupling agent to couple only a fraction of block copolymer anions D-(D/A)-A 1 ( ⁇ ) , thus producing a mixture of block copolymer anions D-(D/A)-A 1 ( ⁇ ) and coupled tapered block copolymer molecules with formula [D-(D/A)-A 1 ] n -X; adding a proton donor compound or an electrophilic monofunctional compound to the reactor, in a limited amount to terminate only part of the block copolymer
  • a dual composition block copolymer comprising two types of block copolymer molecules C and U is produced in-situ in a batch reactor: wherein C is a block copolymer with general formula [D-(D/A)-A 1 ] n -X, and U is a block copolymer with general formula D-(D/A)-A 2 and D-(D/A)-A 1 ; and wherein, D is a polymer block made from conjugated diene and monovinyl aromatic monomers, with conjugated diene repeat units being in predominant molar amount; and wherein, (D/A) is a polymer block that is richer in conjugated diene repeat units towards its end adjacent to D block and that gradually changes its composition until it is substantially richer in monovinyl aromatic repeat units towards its opposite end; and wherein, A 1 and A 2 are polymer blocks comprising monovinyl aromatic repeat units only; and wherein polymer block A 2 has greater molecular weight than polymer block A 1
  • Another embodiment of the present invention is a process for producing a novel dual composition block copolymer comprising: adding a hydrocarbon solvent, a randomizer or polar modifier, and at least a conjugated diene monomer to a reactor, in any order; adding a monofunctional organolithium initiator compound to the reactor and anionically polymerizing the conjugated diene monomer to reach a conversion level from about 80% to about 95% to form a polymer anion of formula B ( ⁇ ) ; adding monovinyl aromatic monomer to the reactor, which initially randomly copolymerizes with the remaining conjugated butadiene monomer, generating a block copolymer anion B-(B/A) ( ⁇ ) up to a point where conjugated diene gets completely converted, thereafter incorporating only monovinyl aromatic monomer to the block copolymer anions up to full conversion of monovinyl aromatic monomer, thus forming polymer anions of formula B-(B/A)-A 1 ( ⁇ ) ; adding to the reactor a
  • a dual composition block copolymer comprising two types of block copolymer molecules C and U is produced in-situ in a batch reactor: wherein C is a block copolymer with general formula [B-(B/A)-A 1 ] n -X, and U is a block copolymer with general formula B-(B/A)-A 2 ; and wherein, B is a polymer block containing conjugated diene repeat units, only; and wherein, (B/A) is a polymer block containing monovinyl aromatic and conjugated diene repeat units that are randomly arranged along the polymer block; and wherein A 1 and A 2 are polymer blocks comprising monovinyl aromatic repeat units, only; and wherein, polymer block A 2 has greater molecular weight than polymer block A 1 ; and wherein, X is the residue of a coupling agent; and wherein, n is an integer that spans from 2 to about 30, depending on the coupling agent employed; and wherein, block
  • Another embodiment of the present invention is a process for producing a novel dual composition block copolymer comprising: adding a hydrocarbon solvent, a randomizer or polar modifier, and at least a conjugated diene monomer to a reactor, in any order; adding a monofunctional organolithium initiator compound to the reactor and anionically polymerizing the conjugated diene monomer to reach a conversion level from about 80% to about 95% to form a polymer anion of formula B ( ⁇ ) ; adding monovinyl aromatic monomer to the reactor, which initially copolymerizes randomly with the remaining conjugated butadiene monomer, generating a block copolymer anion B-(B/A) ( ⁇ ) up to a point where conjugated diene gets completely converted, thereafter adding only monovinyl aromatic monomer to the block copolymer anions up to full conversion of monovinyl aromatic monomer, thus forming polymer anions of formula B-(B/A)-A 1 ( ⁇ ) ; adding to the reactor a coup
  • a dual composition block copolymer comprising two types of block copolymer molecules C and U is produced in-situ in a batch reactor: wherein C is a block copolymer with general formula [B-(B/A)-A 1 ] n -X, and U is a block copolymer with general formula: B-(B/A)-A 2 and B-(B/A)-A 1 ; and wherein, B is a polymer block containing conjugated diene repeat units, only; and wherein, (B/A) is a polymer block containing monovinyl aromatic and conjugated diene repeat units randomly arranged along the polymer block; and wherein, A 1 and A 2 are polymer blocks comprising monovinyl aromatic repeat units, only; and wherein, polymer block A 2 has greater molecular weight than polymer block A 1 ; and wherein, X is the residue of a coupling agent; and wherein, n is an integer that spans from 2 to about 30, depending on
  • Another embodiment of the present invention is a process for producing a novel dual composition block copolymer comprising: adding a hydrocarbon solvent, a randomizer or polar modifier, at least a monovinyl aromatic monomer and at least a conjugated diene monomer to a reactor, in any order; adding a monofunctional organolithium initiator compound to the reactor and anionically copolymerizing the monovinyl aromatic and conjugated diene monomers to full conversion to form a random copolymer anion of formula (B/A) ( ⁇ ) ; adding monovinyl aromatic monomer to the reactor and anionically polymerizing this monomer, which adds to the random copolymer anions (B/A) ( ⁇ ) , thus forming block copolymer anions of formula (B/A)-A 1 ( ⁇ ) ; adding to the reactor a coupling agent in a limited amount to couple only a fraction of block copolymer anions (B/A)-A 1 ( ⁇ ) , thus producing a mixture of block
  • a dual composition block copolymer comprising two types of block copolymer molecules C and U is produced in-situ in a batch reactor: wherein C is a block copolymer with general formula [(B/A)-A 1 ] n -X, and U is a block copolymer with general formula (B/A)-A 2 ; and wherein, (B/A) is a polymer block containing randomized monovinyl aromatic and conjugated diene repeat units; and wherein, A 1 and A 2 are polymer blocks comprising monovinyl aromatic repeat units only; and wherein, polymer block A 2 has greater molecular weight than polymer block A 1 ; and wherein, X is the residue of a coupling agent; and wherein, n is an integer that spans from 2 to about 30, depending on the coupling agent employed; and wherein, block copolymer C has greater molecular weight and lower monovinyl aromatic repeat unit content than block copolymer U.
  • Another embodiment of the present invention is a process for producing a novel dual composition block copolymer comprising: adding a hydrocarbon solvent, a randomizer or polar modifier, at least a monovinyl aromatic monomer, and at least a conjugated diene monomer to a reactor, in any order; adding a monofunctional organolithium initiator compound to the reactor and anionically copolymerizing the monovinyl aromatic and conjugated diene monomers to full conversion to form random copolymer anions of formula (B/A) ( ⁇ ) ; adding monovinyl aromatic monomer to the reactor and anionically polymerizing this monomer, which adds to the random copolymer anions (B/A) ( ⁇ ) , thus forming block copolymer anions of formula (B/A)-A 1 ( ⁇ ) ; adding to the reactor a coupling agent in a limited amount to couple only a fraction of the block copolymer anions (B/A)-A 1 ( ⁇ ) , thus producing a mixture of block
  • a dual composition block copolymer comprising two types of block copolymer molecules C and U is produced in-situ in a batch reactor: wherein C is a block copolymer with general formula [(B/A)-A 1 ] n -X, and U is a block copolymer with general formula (B/A)-A 2 and (B/A)-A 1 ; and wherein, (B/A) is a random copolymer block containing monovinyl aromatic and conjugated diene repeat units; and wherein, A 1 and A 2 are polymer blocks comprising only monovinyl aromatic repeat units; and wherein, polymer block A 2 has greater molecular weight than polymer block A 1 ; and wherein, X is the residue of a coupling agent; and wherein, n is an integer that spans from 2 to about 30, depending on the coupling agent employed; and wherein, block copolymer C has greater molecular weight and lower monovinyl aromatic repeat unit content than block copo
  • Another embodiment of the present invention is a process for producing a novel dual composition block copolymer comprising: adding a hydrocarbon solvent, a randomizer or polar modifier, and at least a conjugated diene monomer to a reactor, in any order; adding a monofunctional organolithium initiator compound to the reactor and anionically polymerizing the conjugated diene monomer to full conversion to form a polymer anion of formula B ( ⁇ ) ; adding monovinyl aromatic monomer to the reactor and anionically polymerizing this monomer, which adds to the polymer anions B ( ⁇ ) , thus forming a block copolymer anions of formula B-A 1 ( ⁇ ) ; adding to the reactor a coupling agent in a limited amount to couple only a fraction of copolymer anions B-A 1 ( ⁇ ) , thus producing a mixture of block copolymer anions B-A 1 ( ⁇ ) and coupled block copolymer molecules with formula [B-A 1 ] n -X; adding a mono
  • a dual composition block copolymer comprising two types of block copolymer molecules C and U is produced in-situ in a batch reactor: wherein C is a block copolymer with general formula [B-A 1 ] n -X, and U is a block copolymer with general formula B-A 2 ; and wherein B is a polymer block containing conjugated diene repeat units, only; and wherein A 1 and A 2 are polymer blocks rich in monovinyl aromatic repeat units; and wherein, polymer block A 2 has greater molecular weight than polymer block A 1 ; and wherein, X is the residue of a coupling agent; and wherein, n is an integer that spans from 2 to about 30, depending on the coupling agent employed; and wherein block copolymer C has greater molecular weight and lower monovinyl aromatic repeat unit content than block copolymer U.
  • Another embodiment of the present invention is a process for producing a novel dual composition block copolymer comprising: adding a hydrocarbon solvent, a randomizer or polar modifier, and at least a conjugated diene monomer to a reactor, in any order; adding a monofunctional organolithium initiator compound to the reactor and anionically polymerizing the conjugated diene monomer to full conversion to form a polymer anion of formula B ( ⁇ ) ; adding monovinyl aromatic monomer to the reactor and anionically polymerizing this monomer, which adds to the polymer anions B ( ⁇ ) , thus forming block copolymer anions of formula B-A 1 ( ⁇ ) ; adding to the reactor a coupling agent in a limited amount to couple only a fraction of copolymer anions B-A 1 ( ⁇ ) , thus producing a mixture of block copolymer anions B-A 1 ( ⁇ ) and coupled block copolymer molecules with formula [B-A 1 ] n -X; adding a proton donor
  • a dual composition block copolymer comprising two types of block copolymer molecules C and U is produced in-situ in a batch reactor: wherein C is a block copolymer with general formula [B-A 1 ] n -X, and U is a block copolymer with general formula B-A 2 and B-A 1 ; and wherein, B is a polymer block containing conjugated diene repeat units, only; and wherein, A 1 and A 2 are polymer blocks rich in monovinyl aromatic repeat units; and wherein, polymer block A 2 has greater molecular weight than polymer block A 1 ; and wherein, X is the residue of a coupling agent; and wherein, n is an integer that spans from 2 to about 30, depending on the coupling agent employed; and wherein, block copolymer C has greater molecular weight and lower monovinyl aromatic repeat unit content than block copolymer U.
  • proton donors and/or monofunctional electrophilic terminating agents are fed to partially deactivate block copolymer anions before block copolymerization of a second charge of monovinyl aromatic monomer.
  • Such terminating agents can be added in an independent charge to the reactor, or may be fed to the reactor simultaneously with coupling agent, or with the second charge of monovinyl aromatic monomer.
  • Examples of such terminating agents are water, polymerization inhibitors as tert-butil catechol, phenolic antioxidants, alcohols, organic acids, inorganic acids, trimethylchlorosilane, and the like.
  • Block copolymerization is typically carried out in inert hydrocarbon solvents under inert atmosphere with highly purified reagents to prevent the premature termination of the polymerization reaction.
  • Suitable solvents to practice this invention include, but are not limited to, pentane, hexane, heptane, octane, decane, cyclopentane, cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane, benzene, naphthalene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, n-propylbenzene, isopropylbenzene, n-butylbenzene, and the like or mixtures thereof. Cyclohexane is a preferred solvent for this present invention.
  • randomizers also known as polar modifiers, are employed to promote random copolymerization of monovinyl aromatic and conjugated diene monomers to form (B/A) random polymer blocks as well as to accelerate addition of monovinyl aromatic monomers to polymer anions ending in conjugated dienyl lithium units. Randomizers also raise 1,2 and 3,4-addition of conjugated dienes anionically polymerized. Nevertheless, 1,2-vinyl and 3,4-vinyl added conjugated diene repeat units are more reactive towards crosslinking/vulcanizing reactions.
  • an optimal amount of polar modifier compound should be selected to balance the rate of copolymerization in the process to make the dual composition block copolymer of the invention and the crosslinking kinetics of the microcellular rubber compound of the invention. Acceleration of block polymerization kinetics and enrichment of 1,2-vinyl and 3,4-vinyl addition during conjugated diene polymerization varies depending on the polar modifier selected, a behavior that is well known by the skilled in the art.
  • Polar modifiers that may be used to produce the dual composition block copolymer of the present invention include Lewis bases such as ethers, tertiary amines, aminoethers and group IA alkali metal alkox ides, and combinations thereof.
  • ether polar modifiers include, but are not limited to, monofunctional, multifunctional and oligomeric alkyl and cyclic ethers, such as dimethyl ether, diethyl ether, ethyl methyl ether, ethyl propyl ether, di-n-propyl ether, methyl tert-butyl ether, tetramethylene oxide (tetrahydrofuran), 1,2-dimethoxyethane, bis-tetrahydrofuran, ditetrahydrofurylpropane (DTHFP), ethyl tetrahydrofurfuryl ether.
  • monofunctional, multifunctional and oligomeric alkyl and cyclic ethers such as dimethyl ether, diethyl ether, ethyl methyl ether, ethyl propyl ether, di-n-propyl ether, methyl tert-butyl ether, tetramethylene oxide (tetrahydrofur
  • tertiary amine polar modifiers include, but are not limited to, monofunctional, multifunctional or oligomeric alkyl and cyclic tertiary amines such as dimethylethyl amine, trimethyl amine, triethylamine, N,N,N′,N′-tetramethyl ethylene diamine (TMEDA), N,N,N′,N′′,N′′-Pentamethyldiethylenetriamine, 1,3,5-trimethylhexahydro-1,3,5-triazine, combinations thereof, and the like.
  • TEDA trimethyl amine
  • N,N,N′,N′′,N′′-Pentamethyldiethylenetriamine 1,3,5-trimethylhexahydro-1,3,5-triazine, combinations thereof, and the like.
  • aminoether polar modifiers include, but are not limited to, tetrahydrofurfuryl-N,N-dimethylamine, bis(2-(Dimethylamino)ethyl) ether, 2,2-dimorpholinoethyl ether, and the like, and mixtures thereof.
  • Group IA alkali metal alkoxides lithium, sodium, potassium, rubidium and cesium salts
  • suitable Group IA alkali metal alkoxides include, but are not limited to, monofunctional, multifunctional and oligomeric alkyl and cyclic metal alkoxides such as sodium tert-butoxide, sodium tert-amylate, sodium mentholate, potassium tert-butoxide, potassium tert-amylate, potassium mentholate, potassium 3,7-dimethyl-3-octanolate and the like, and mixtures thereof.
  • Polar modifiers can be loaded directly to the reactor or can be previously dissolved in the solvent for use in the process.
  • Polar modifier concentration in the reaction system of the invention is from 5 to 5000 parts per million weight parts of solvent, more preferably from 10 to 1000 parts per million weight parts of solvent, most preferably from 20 to 100 parts per million weight parts of solvent.
  • Suitable conjugated diene monomers for use in making the dual composition block copolymers of the present invention include, but are not limited to, 1,3-butadiene, isoprene, 1,3-pentadiene, methylpentadiene, phenylbutadiene, 2,3-dimethyl-1,3-butadiene, 2,4-hexadiene, 1,3-hexadiene, 1,3-cyclohexadiene, 3,4-dimethyl-1,3-hexadiene, 1,3-octadiene, 4,5-diethyl-1,3-octadiene, and combinations thereof.
  • Suitable monovinyl aromatic monomers for use in making the dual composition block copolymers of the present invention include, but are not limited to, styrene, 3-methylstyrene, ⁇ -methyl styrene, p-methyl styrene, ⁇ ,4-dimethyl styrene, t-butyl styrene, o-chlorostyrene, 2-butenyl naphthalene, 4-t-butoxystyrene, 3-isopropenyl biphenyl, 4-vinylpyridine, 2-vinylpyridine, isopropenyl naphthalene, 4-n-propylstyrene, and combinations thereof.
  • the dual composition block copolymer of the invention is prepared by anionic polymerization by contacting anionically polymerizable monomers with a monofunctional organolithium compound as an initiator.
  • a monofunctional organolithium compound as an initiator.
  • the preferred class of these compounds can be represented by the formula RLi wherein R is a hydrocarbon radical selected from the group consisting of aliphatic, cycloaliphatic, and aromatic radicals containing from 1 to 20 carbon atoms, although higher molecular weight initiators can be used.
  • R is a hydrocarbon radical selected from the group consisting of aliphatic, cycloaliphatic, and aromatic radicals containing from 1 to 20 carbon atoms, although higher molecular weight initiators can be used.
  • Many anionic polymerization initiators are well known and commercially available.
  • Monofunctional organolithium compounds, such as butyllithium are examples of commonly used initiators.
  • initiators include methyllithium, ethyllithium, tert-butyllithium, sec-butyllithium, n-butyllithium, n-decyllithium, isopropyllithium, eicosyllithium, cycloalkyllithium compounds, such as cyclohexyllithium, and aryllithium compounds, such as phenyllithium, naphthllithium, p-toluyllithium, 1,1-diphenylhexyllithium, and the like.
  • Monofunctional organolithium compounds substituted with protected polar functional groups may also be used as initiators for anionic polymerization.
  • the amount of monofunctional organolithium initiator varies depending upon the desired viscosity of the dual composition block copolymer and the purity levels of the solvent and monomers employed in the process for making it.
  • the amount of monofunctional organolithium initiator in the process of making the dual composition block copolymer of the invention is from about 2 millimoles to about 30 millimoles per kilogram of total conjugated diene monomer plus monovinyl aromatic monomer loaded to the reactor, more preferably from about 12 millimoles to about 26 millimoles per kilogram of total conjugated diene monomer plus monovinyl aromatic monomer loaded to the reactor, most preferably from about 16 millimoles to about 22 millimoles per kilogram of total conjugated diene monomer plus monovinyl aromatic monomer loaded to the reactor.
  • the anionic polymerization is normally carried out at temperatures in the range from ⁇ 100° C. to 150° C., preferably between 25° C. and 120° C. Normally 50 to 90% by weight of a reaction solvent is used to control the viscosity inside the reaction zone, preferably 70 to 85%. Typical residence times for anionic polymerization vary depending on the reaction temperature, monomer concentration and initiator level between 0.1 and 5 hours, preferable from 0.2 to 1 hour.
  • the anionically polymerized block copolymer anions undergo partial coupling.
  • Partial coupling means that a portion of the total living anionically polymerized polymer chain-ends undergo coupling with coupling agents.
  • Reaction of living anionically polymerized block copolymer chain-ends with suitable coupling agents render coupled block copolymers without anionic active centers for further polymerization.
  • the coupling agents desirably couple between 2 and 30 anionically polymerized polymer chains, although coupling agents capable of coupling a greater number of chains may also be employed.
  • Suitable coupling agents for use in the partial coupling step include, but are not limited to, epoxidized soybean oil, silicon halides, functionalized silicon compound such as a silane compound and functionalized oligomeric compounds such as the ones listed in U.S. Pat. No. 7,517,934. The entire disclosure of U.S. Pat. No. 7,517,934 is incorporated herein by reference. Silicon tetrachloride, methyl silicon trichloride and dimethyl silicon dichloride are specific examples of suitable coupling agents, with silicon tetrachloride being particularly well-suited for this application.
  • the partial coupling is achieved by controlling the stoichiometric ratio of coupling agent to living polymer.
  • the partial coupling provides a block copolymer blend with desired properties.
  • the total reaction mixture is then treated to terminate block copolymer anions and recover the dual composition block copolymer of the present invention.
  • This termination is accomplished by feeding to the reactor a proton donor compound, such as water, an alcohol, or an organic or inorganic acid.
  • the amount of terminating agent to be added needs to be at least in a stoichiometric amount respective to the amount of block copolymer anions remaining in the reactor.
  • a further step in all the embodiments of the process of making the dual composition block copolymer of the present invention is that it is desirable to add an antioxidant system while the dual composition block copolymer is still in hydrocarbon solution.
  • the antioxidant system protects the dual composition block copolymer from degradation during later processing steps to isolate it from solvent and to prolong the shelf life of the final product.
  • a wide variety of antioxidant systems are well known in the art, and any system can be used without limiting the scope of the present invention.
  • Preferred antioxidant systems consist of a synergistic blend of hindered phenolic and phosphite type antioxidants.
  • Suitable hindered phenolic type antioxidants include, but are not limited to, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxylbenzyl)benzene, pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxypheyl)propionate, 2,4-bis(octylmercapto)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, 2,4-bis(octylthiomethyl)-6-methylphenol, 2,4-bis(dodecylthiomethyl)-6-methylphenol, 2-(1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl)-4,6-d
  • phospite type antioxidants include, but are not limited to, tris(nonylphenyl) phosphite, tris(2,4-ditert-butylphenyl) phosphite, butylidenebis[2-tert-butyl-5-methyl-p-phenylene]-P,P,P′,P′-tetratridecylbis(phosphine), 3,9-Bis(2,4-di-tert-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters of phosphorous acid, 3,9-Bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-
  • An additional step in all the embodiments of the process of making the dual composition block copolymer of the invention is to isolate the dual composition block copolymer from the solvent by any of the finishing process well known in the art, such as roll milling, vacuum assisted devolatilization, precipitation and drying, steam stripping followed by dewatering and drying, and the like.
  • An optional step in all the embodiments of the process of making the dual composition block copolymer of the invention is to incorporate extender oil to the dual composition block copolymer.
  • Oil can be added while the dual composition block copolymer is still in hydrocarbon solvent solution, or afterwards at any stage of its finishing process.
  • oils to perform oil extension include, but are not limited to: mineral oil, paraffinic oil, naphthenic oils, relatively naphthenic oil, relatively aromatic oil, aromatic oil, highly aromatic oil, extremely high aromatic oil and the like, or mixtures of thereof.
  • Preferred oil content is from 0 to 12 parts per hundred weight parts of the dual composition block copolymer, more preferably from 0 to 10 parts per hundred weight parts of the dual composition block copolymer, and most preferably from 0 to 8 parts per hundred weight parts of the dual composition block copolymer.
  • compositions to produce crosslinked microcellular rubber compounds comprising:
  • a preferred embodiment of the present invention is a composition to produce crosslinked microcellular compound, comprising:
  • a dual composition block copolymer comprising: two types of block copolymer molecules C and U, where:
  • blowing agent or a mixture of chemical blowing agents, in an amount from 1 to 10 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crosslinked microcellular rubber compound
  • crosslinking agent or a mixture of crosslinking agents, in an amount from 0.5 to 5 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crosslinked microcellular rubber compound.
  • composition may include one or more optional additives, such as:
  • polystyrene-butadiene random copolymers including styrene-butadiene random copolymers, styrene-isoprene-butadiene random copolymers, natural rubbers, polybutadienes, polyisoprene rubbers, ethylene/ ⁇ -olefin/non-conjugated diene terpolymers, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, or any mixture thereof, where such polymers preferably comprise from 0 to about 50 parts per hundred weight parts of polymeric raw materials in the formulation to produce the crosslinked microcellular rubber compound;
  • a filler or a mixture of fillers or rubber vulcanized compound powder preferably in an amount from 0 to about 200 parts per hundred weight parts of polymeric raw materials comprised in the formulation to produce the crosslinked microcellular rubber compound;
  • plasticizer or a mixture of plasticizers in an amount from 0 to 40 parts per hundred weight parts of polymeric raw materials comprised in the formulation to produce the crosslinked microcellular rubber compound;
  • antioxidants preferably in an amount of from 0 to 2 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crossl inked microcellular rubber compound;
  • blowing agent activator or a mixture of chemical blowing agent accelerators, preferably in an amount from 0 to about 5 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crosslinked microcellular rubber compound;
  • crosslinking agent activator or a mixture of crosslinking agent activators, preferably in an amount from 0 to 5 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crosslinked microcellular rubber compound;
  • crosslinking accelerator or a mixture of crosslinking accelerators, preferably in an amount from 0 to 5 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crosslinked microcellular rubber compound;
  • vulcanization retarders such as vulcanization retarders, antiozonant, UV stabilizers, light stabilizers, fragrances or odorants, anti-termite agents, antimicrobials, metal deactivators, dyes, pigments, mold release agents, and the like and mixtures thereof.
  • composition for making a crosslinked microcellular compound comprising:
  • a dual composition block copolymer comprising two types of block copolymer molecules C and U, where block copolymer C has the general formula [B-(B/A)-A 1 ] n -X and block copolymer U has the general formula B-(B/A)-A 2 or B-(B/A)-A 2 and B-(B/A)-A 1 , where B is a polymer block made from one or more conjugated diene monomers only, where (B/A) is a polymer block made from at least a conjugated diene monomer and at least a monovinyl aromatic monomer, where conjugated diene and monovinyl aromatic repeat units are randomly arranged along the polymer block, where A 1 and A 2 are polymer blocks made from monovinyl aromatic monomer only, where polymer block A 2 has greater molecular weight than polymer block A 1 , where X is the residue of a coupling agent, where n is an integer with a value from 2 to 30, where the amount
  • blowing agent or a mixture of chemical blowing agents, preferably in an amount from 1 to 10 parts per hundred weight parts of polymeric raw materials comprised in the formulation to produce the crosslinked microcellular rubber compound;
  • crosslinking agent or a mixture of crosslinking agents, preferably in an amount from 0.5 to 5 parts per hundred weight parts of polymeric raw materials comprised in the formulation to produce the crosslinked microcellular rubber compound.
  • composition may include one or more optional additives, such as:
  • polystyrene-butadiene random copolymers including styrene-butadiene random copolymers, styrene-isoprene-butadiene random copolymers, natural rubbers, polybutadienes, polyisoprene rubbers, ethylene/ ⁇ -olefin/non-conjugated diene terpolymers, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, or any mixture thereof, where such polymers preferably comprise from 0 to about 50 parts per hundred weight parts of polymeric raw materials in the formulation to produce the crosslinked microcellular rubber compound;
  • a filler or a mixture of fillers or rubber vulcanized compound powder preferably in an amount from 0 to about 200 parts per hundred weight parts of polymeric raw materials comprised in the formulation to produce the crosslinked microcellular rubber compound;
  • plasticizer or a mixture of plasticizers in an amount from 0 to 40 parts per hundred weight parts of polymeric raw materials comprised in the formulation to produce the crosslinked microcellular rubber compound;
  • antioxidants preferably in an amount of from 0 to 2 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crosslinked microcellular rubber compound;
  • blowing agent activator or a mixture of chemical blowing agent accelerators, preferably in an amount from 0 to about 5 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crosslinked microcellular rubber compound;
  • crosslinking agent activator or a mixture of crosslinking agent activators, preferably in an amount from 0 to 5 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crosslinked microcellular rubber compound;
  • crosslinking accelerator or a mixture of crosslinking accelerators, preferably in an amount from 0 to 5 parts per hundred weight parts of polymeric raw materials included in the formulation to produce the crosslinked microcellular rubber compound;
  • vulcanization retarders such as vulcanization retarders, antiozonant, UV stabilizers, light stabilizers, fragrances or odorants, anti-termite agents, antimicrobials, metal deactivators, dyes, pigments, mold release agents, and the like and mixtures thereof.
  • composition to produce crosslinked microcellular compound comprising:
  • a dual composition block copolymer comprising two types of block copolymer molecules C and U, where: block copolymer C has the general formula [B-A 1 ] n -X and block copolymer U has the general formula B-A 2 or B-A 2 and B-A 1 ; B is a polymer block made from one or more conjugated diene monomers; A 1 and A 2 are polymer blocks made from monovinyl aromatic monomer; polymer block A 2 has greater molecular weight than polymer block A 1 ; X is the residue of a coupling agent; and n is an integer with a value from 2 to 30, preferably where the amount of dual composition block copolymer is from 50 to 100 parts per hundred weight parts of polymeric raw materials in the formulation to produce the crosslinked microcellular rubber compound;
  • blowing agent or a mixture of chemical blowing agents, preferably in an amount from 1 to 10 parts per hundred weight parts of polymeric raw materials in the formulation
  • crosslinking agent or a mixture of crosslinking agents, preferably in an amount from 0.5 to 5 parts per hundred weight parts of polymeric raw materials in the formulation.
  • polystyrene-butadiene random copolymers such as: as styrene-butadiene random copolymers, styrene-isoprene-butadiene random copolymers, natural rubbers, polybutadienes, polyisoprene rubbers, ethylene/ ⁇ -olefin/non-conjugated diene terpolymers, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, and any mixture thereof, preferably where such polymers comprise from 0 to about 50 parts per hundred weight parts of polymeric raw materials in the formulation to produce the crosslinked microcellular rubber compound.
  • a filler or a mixture of fillers or rubber vulcanized compound powder preferably in an amount from 0 to about 200 parts per hundred weight;
  • plasticizer or a mixture of plasticizers, preferably in an amount from 0 to 40 parts per hundred weight;
  • antioxidants preferably in an amount from 0 to 2 parts per hundred weight
  • blowing agent activator and/or a mixture of chemical blowing agent accelerators, preferably in an amount from 0 to about 5 parts per hundred weight;
  • crosslinking agent activator or a mixture of crosslinking agent activators, preferably in an amount from 0 to 5 parts per hundred weight;
  • crosslinking accelerator or a mixture of crosslinking accelerators, preferably in an amount from 0 to 5 parts per hundred weight;
  • vulcanization retarders such as vulcanization retarders, antiozonant, UV stabilizers, light stabilizers, fragrances or odorants, anti-termite agents, antimicrobials, metal deactivators, dyes, pigments, mold release agents, and the like, and mixtures thereof.
  • compositions to produce a crosslinked microcellular compound comprising: a dual composition block copolymer; blowing agent; and a crosslinking agent.
  • the dual composition block copolymer comprises block copolymer molecules C and U, where:
  • block copolymer C has the general formula [(B/A)-A 1 ] n -X and block copolymer U has the general formula (B/A)-A 2 or (B/A)-A 2 and (B/A)-A 1 ;
  • (B/A) is a polymer block made from at least a conjugated diene monomer and at least a monovinyl aromatic monomer, preferably where conjugated diene and monovinyl aromatic repeat units are randomly arranged along the polymer block;
  • a 1 and A 2 are polymer blocks made from monovinyl aromatic monomer only, where polymer block A 2 has a greater molecular weight than polymer block A 1 ;
  • X is the residue of a coupling agent
  • n is an integer with a value from 2 to 30, preferably where the amount of dual composition block copolymer is from 50 to 100 parts per hundred weight parts of polymeric raw materials comprised in the formulation to produce the crosslinked microcellular rubber compound.
  • the blowing agent is preferably added in an amount from 1 to 10 parts per hundred weight, and the crosslinking agent is preferably added in an amount from 0.5 to 5 parts per hundred weight.
  • ingredients in the formulation in parts per hundred weight of polymeric raw materials in the formulation to produce the crosslinked microcellular rubber compound include:
  • polystyrene-butadiene random copolymers such as styrene-butadiene random copolymers, styrene-isoprene-butadiene random copolymers, natural rubbers, polybutadienes, polyisoprene rubbers, ethylene/ ⁇ -olefin/non-conjugated diene terpolymers, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, and any mixture thereof, preferably in an amount of from 0 to about 50;
  • a filler preferably in an amount from 0 to about 200 parts;
  • plasticizer or a mixture of plasticizers, preferably in an amount from 0 to 40 parts;
  • antioxidants preferably in an amount from 0 to 2 parts;
  • blowing agent activator or a mixture of chemical blowing agent accelerators, preferably in an amount from 0 to about 5 parts;
  • crosslinking agent activator or a mixture of crosslinking agent activators, preferably in an amount from 0 to 5 parts per hundred weight parts;
  • crosslinking accelerator or a mixture of crosslinking accelerators, preferably in an amount from 0 to 5 parts;
  • vulcanization retarders such as vulcanization retarders; antiozonants; UV stabilizers; light stabilizers; fragrances or odorants; anti-termite agents; biocide agents; antifungal agents; antimicrobial agents; antibacterial agents; metal deactivators; dyes; pigments; mold release agents, and the like, and mixtures thereof.
  • Suitable fillers for use in crosslinked microcellular rubber foam composition of the present invention include, but are not limited to, carbon black, silica, calcium silicate, aluminum silicate, magnesium silicate, sodium silicate, potassium silicate, chalk, dolomite, kaolin clay, calcined clay, hard clay, activated clay, halloysite, sericite, wollastonite, bentonite, light calcium carbonate, heavy calcium carbonate, magnesium carbonate, talc, diatomaceous earth, titanium oxide, zinc oxide, calcium oxide, aluminum hydroxide, magnesium hydroxide, gypsum, mica, barium sulfate, calcium sulfate, alumina trihydrate, natural fibers, synthetic fibers, and combinations thereof.
  • Suitable plasticizers for use in crosslinked microcellular rubber foam composition of the present invention include, but are not limited to, mineral oils, such as paraffinic oil, naphthenic oil, relatively naphthenic oil, relatively aromatic oil, aromatic oil, highly aromatic oil and extremely aromatic oil; paraffins, such as unbranched paraffins, isoparaffins, ceresines, isoceresines, paraffin wax, and other mineral waxes; petroleum distillation residues, such as montan waxes, ozocerite, asphaltines, bitumens and pitches; fatty acids, such as stearic acid or palmitic acid; fatty acid metal salts, such zinc soap of unsaturated fatty acid, zinc soap of saturated fatty acid, calcium soap of unsaturated fatty acid, zinc stearate and calcium stearate; organic acid monoesters, such as alkyl or alkoxyalkyl oleates and stearates; organic acid diesters, such as dialkyl, dialkoxyalkyl, and alkyl ary
  • Suitable antioxidants for use in crosslinked microcellular rubber foam composition of the present invention include, but are not limited to, hindered phenols such as 2,6-di-t-butyl-p-cresol (BHT), 2,4-dimethyl-6-t-butyl phenol, 2,4-dimethyl-6-( ⁇ -methyl-cyclohexyl)-phenol, 4-methoxymethyl-2,6-di-t-butyl-phenol, butylated reaction product of p-cresol and dicyclopentadiene, alkylated phenol, styrenated and alkylated phenol, styrenated phenol (SPH), pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl]-4-
  • Suitable blowing agents for use in crosslinked microcellular rubber foam composition of the present invention include, but are not limited to organic chemical blowing agents, such as azodicarbonamide (ADC), N,N′dinitrosopentamethylenetetramine (DNPT), benzenesulfohydrazide (BSH), benzene-1,3-disulfohydrazide, 4,4′-oxybis(benzenesulfonyl hydrazide), p-toluenesulfonic acid hydrazide, toluenesulfonylsemicarbazide, 5-phenyltetrazole, trihydrazine triazine; inorganic chemical blowing agents such as sodium hydrogen carbonate, sodium carbonate, ammonium hydrogen carbonate, ammonium carbonate, potassium hydrogen carbonate, potassium carbonate; physical blowing agents, such as highly pressurized nitrogen or supercritical carbon dioxide, and combinations thereof.
  • organic chemical blowing agents such as azodicarbonamide (
  • Suitable chemical blowing agent activators for use in crosslinked microcellular rubber foam composition of the present invention include, but are not limited to zinc oxide, zinc benzenesulphinate, zinc stearate, zinc 2-ethylhexanoate, zinc carbonate, zinc ditolyl sulfonate, calcium carbonate, calcium oxide, magnesium oxide, silica, urea, stearic acid, adipic acid, triethanolamine, diphenylamine derivatives, and combinations thereof.
  • Suitable crosslinking agents for use in the crosslinked microcellular rubber foam composition of the present invention include, but are not limited to sulfur; sulfur donors, such as dithiodimorpholine (DTDM), caprolactamdisulfide, N,N′-dithio bis-(hexahydro-2H-azepinone) (CLD), 2-morpholino-dithio-benzothiazole (MBSS), dipentamethylene thiuramtetrasulfide (DPTT), N-oxydiethylene dithiocarbamyl-N′-oxydiethylene sulfonamide (OTOS), and tetramethyl thiuramdisulfide (TMTD); and organic peroxides, such as dicumyl peroxide, t-butyl perbenzoate, t-butyl cymyl peroxide, di-t-butylperoxide, lauroyl peroxide, 2,5-dimethyl-2,5-di-(t-buty
  • Suitable crosslinking accelerators for use in crosslinked microcellular rubber foam composition of the present invention include, but are not limited to mercapto accelerators, such as 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), zinc-2-mercaptobenzothiazole (ZMBT); sulfonamide accelerators, such as N-cyclohexyl-2-benzothiazylsulfenamide (CBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), and 2-benzothiazyl-N-sulfenemorpholide (MBS); thiuram accelarators, such as tetramethylthiuram disulfide (TMTD), tetramethylthiuram monosulfide (TMTM) and tetraethylthiuram disulfide (TETD); dithiocarbamate accelerators, such as zinc dimethyldithiocarbamate (Z
  • Suitable crosslinking agent activators for use in the crosslinked microcellular rubber foam composition of the present invention include, but are not limited to, zinc oxide, magnesium oxide, Ca(OH) 2 , stearic acid, zinc stearate, zinc laureate, dibutylaminooleate, 1,3-diphenylguanidinephthalate, monoethanolamine, diethanolamine, triethanolamine, dibutylamine, dibenzylamine, and mixtures thereof.
  • compositions to produce hot-melt pressure sensitive adhesives comprising:
  • a preferred embodiment of the present invention is a hot-melt pressure sensitive adhesive composition, comprising:
  • Suitable tackifier resins for use in the formulation of hot-melt pressure sensitive adhesive of the present invention include, but are not limited to: rosin esters, such as Sylvalite® RE100L, Sylvalite® RE115, Sylvalite® RE85L, Foral® 85, Foral® 105, Pentalyn® H, and Permalyn® 3100; styrenated terpenes, such as Sylvares® ZT5100, Sylvares® ZT105LT, and Sylvares® ZT115LT; polyterpene resins, such as Sylvares® TR1100, and Sylvares® TR7115; terpene phenolics, such as Sylvares® TP2040, and Sylvares® TP115; aliphatic hydrocarbon resins, such as Piccotac® 1100, Piccotac® 115, and Wingtack® 95; hydrogenated hydrocarbon resins, such as Eastotac
  • Sylvalite® and Sylvares® tackifiers are commercially available from Kraton Corporation.
  • Foral®, Pentalyn®, Permalyn®, Piccotac®, and Eastotac® tackifiers are commercially available from Eastman Chemical Company.
  • Wingtack® tackifiers are commercially available from Total CrayValley.
  • Suitable extender oils or plasticizers for use in the formulation of hot-melt pressure sensitive adhesive of the present invention include, but are not limited to: mineral oils, naphtenic oils and paraffinic oils.
  • Suitable antioxidants for use in the formulation of hot-melt pressure sensitive adhesive of the present invention include, but are not limited to: phenolic antioxidants, such as Irganox® 1010, Irganox® 1076, Irganox® 565, Irganox® 1520, Irganox® 1098, Anox® 20, or Ultranox® 276; phosphite antioxidants, such as: Alkanox® TNPP, Alkanox® 240, Ultranox® 626, or Weston® 618F; thioester antioxidants, such as Naugard DSTDP; and mixtures of them, such as Ultranox® 877A. Irganox® antioxidants are commercially available from BASF; Anox®, Ultranox®, Alkanox®, Weston® and Naugard® antioxidants are commercially available from Addivant.
  • phenolic antioxidants such as Irganox® 1010, Irganox® 1076, Irganox® 565, Irga
  • Dual composition block copolymers, as well as previous art copolymers synthetized in the following examples and comparative examples, are characterized by the following techniques: Proton nuclear magnetic resonance ( 1 H-NMR or proton NMR), employing a 300 MHz Bruker, model Fourier 300 Spectrometer, to quantify total styrene repeat unit content, as well as block styrene content. Total styrene repeat unit content in the block copolymers is measured as indicated by International Standard ISO 21561-1.
  • total styrene repeat unit content is reported as weight percentage, on a total block copolymer weight basis.
  • Block styrene content measurement accounts for styrene repeat units incorporated as homopolymer blocks; i.e. the amount of styrene repeat units forming part of a given block copolymer which have no covalent bonds to conjugated diene monomer.
  • Block styrene content is measured by proton NMR as reported in U.S. Pat. No. 9,771,473 B2.
  • block styrene content is reported as weight percent, on a total block copolymer basis.
  • styrene is the only monovinyl aromatic monomer employed, the total monovinyl aromatic repeat unit content (% A t ) quantitatively corresponds to the total styrene content measured in the examples.
  • monovinyl aromatic repeat unit blockiness degree in these examples is calculated from the quotient of block styrene content to total styrene content, and reported as a mole percent on a monovinyl aromatic repeat unit basis.
  • GPC Gel permeation chromatography
  • elution time constructed from narrow MWD polystyrene standards, were employed to measure molecular weight distribution, weight average molecular weight (M w ) and the polydispersity index of molecular weight distribution (the ratio of weight average molecular weight and number average molecular weight, M w /M n ) of the different block copolymer analyzed.
  • GPC-RI was also used to quantify the amount of coupled block copolymer (% C ri ) by integration of the peak with highest molecular weight, and reported as percentage of the whole GPC-RI molecular weight distribution of the block copolymer analyzed, whenever multiple peaks appeared in the molecular weight distribution.
  • the signal of the diode array detector at a wavelength of 261 nm which only responds to the amount of monovinyl aromatic repeat units in the block copolymer, as well as a universal molecular weight calibration curve referred to narrow MWD polystyrene standards, was employed to measure the monovinyl aromatic repeat unit weighted coupled block copolymer content (% C uv ); % C uv is obtained by integration of the highest molecular weight peak in the monovinyl aromatic repeat unit weighted molecular weight distribution, and reported as percentage of the whole GPC-UV monovinyl aromatic repeat unit weighted molecular weight distribution, whenever multiple peaks appeared in the molecular weight distribution.
  • the % A t i.e. total styrene repeat unit content
  • the % C ri resulting from GPC-RI, and the % C uv resulting from GPC-UV are then used to calculate the monovinyl aromatic repeat unit weight percent content in the block copolymer uncoupled fraction, % A U , and are also used to calculate the monovinyl aromatic repeat unit weight percent content of the block copolymer coupled fraction, % A C .
  • they are used to calculate the monovinyl aromatic repeat unit compositional difference between uncoupled and coupled fractions of the block copolymers, % CD, as follows:
  • Viscoelastic properties of the block copolymers prepared in the examples are evaluated in an RPA 2000 equipment from Alpha Technologies. Oscillatory shear measurements were performed at a temperature of 100° C., at maximum strain of 13.95%. Complex dynamic shear viscosity ( ⁇ *) is reported at oscillation frequencies of 0.99 and 100 rad/s, while tan delta is reported at several oscillation frequencies, sweeping a frequency range from 0.25 to 200 rad/s. Mooney viscosity (ML 1+4) was determined at 100° C., using a Monsanto Mooney MV 2000 equipment, following to ASTM D1646.
  • Coupled tapered block copolymer content (% C ri ) was 27.4% of total block copolymer molecular weight distribution, as determined by GPC-RI.
  • Monovinyl aromatic repeat unit weighted coupling level by GPC-UV (% C uv ) was 22.0%.
  • Total styrene repeat unit content of the dual composition block copolymer was 40.0 wt. %, whereas block styrene content was 31.8 wt %. Therefore, the monovinyl aromatic repeat unit blockiness degree in the dual composition block copolymer was 79.5 mole %.
  • Monovinyl aromatic repeat unit content in the un-coupled tapered block copolymer fraction (% A C ) was 32.2 wt.
  • Tan delta of dual composition block copolymer revealed predominately elastic behavior (Tan delta smaller than 1.00) in the whole frequency sweep from 0.25 to 200 rad/s, with a maximum value of 0.81 at 2.51 rad/s. Details of rheological characterization of this dual composition block copolymer is shown in Table 3.
  • a process for making a dual composition block copolymer comprising the steps of:
  • a solvent such as cyclohexane, a monovinyl aromatic monomer such as styrene and a conjugated diene monomer such as butadiene in a reactor to provide initial contents [with or without a randomizer or a polar modifier for alternative embodiments];
  • a coupling agent such as a silicon tetrachloride or methyl silicon trichloride
  • the polymeric anions are partially terminated at this stage.
  • a terminator to the reactor such as a monofunctional alcohol, thereby terminating polymeric anions.
  • an antioxidant such as a phenolic antioxidant and/or a phosphite antioxidant to the reactor;
  • % CD is between 10 and 35%, preferably between 15 and 30%, more preferably between 17 and 28% with 20 to 26% being typical and 25.6% being a particular example.
  • Molecular weight distribution exhibited a polydispersity index of 1.19.
  • Coupled tapered block copolymer content (% C ri ) was 25.5% of total block copolymer molecular weight distribution, as determined by GPC-RI.
  • Total styrene repeat unit content of the dual composition block copolymers was 40.2 wt. %, whereas styrene block contents was 32.1 wt %. Therefore, monovinyl aromatic repeat unit blockiness degree was 79.9 mole %.
  • Specific GPC and NMR characterization of this dual composition block copolymer is depicted in Table 2.
  • Complex dynamic shear viscosity of dual composition block copolymer at 0.99 rad/s was 72962 Pa-s and dropped to 4833 Pa-s when evaluated at oscillating frequency of 100 rad/s.
  • Tan delta of dual composition block copolymer revealed predominately elastic behavior (Tan delta less than 1.00) in the whole frequency sweep from 0.25 to 200 rad/s, with a maximum value of 0.86 at 0.99 rad/s. Details of rheological characterization of this dual composition block copolymers is shown in Table 3.
  • Block copolymer was recovered by steam stripping and oven drying. Weight average molecular weight (M w ) of block copolymers synthetized varied from 147.4 to 225.5 kg/mol. Molecular weight distribution exhibited a polydispersity index from 1.24 to 1.40.
  • the molecular weight distribution by GPC-RI of dual composition block copolymer produced in Example 2 is shown in FIG. 1 . Coupled tapered block copolymer content (% C ri ) varied from 23.0 to 38.6% of total block copolymer molecular weight distribution as determined by GPC-RI.
  • Monovinyl aromatic weighted coupling level by GPC-UV (% C uv ) was in a range from about 14.6 to about 24.6%.
  • Total styrene repeat unit contents of the dual composition block copolymers were from 39.9 to 40.8 wt %, whereas styrene block contents were from 30.5 wt % to 35.6%. Therefore, monovinyl aromatic repeat unit blockiness degrees of the dual composition block copolymers varied from 76.5 mole % to 87.5 mole %.
  • Vinyl aromatic repeat unit contents in the un-coupled tapered block copolymer fraction (% A C ) were from about 24.8 to about 32.6 wt.
  • FIG. 1 Molecular weight distribution by GPC-RI of dual composition block copolymer produced in Example 13 is shown in FIG. 1 .
  • Coupled tapered block copolymer content (% C ri ) was 37.4% of total block copolymer molecular weight distribution as determined by GPC-RI.
  • Monovinyl aromatic weighted coupling level by GPC-UV (% C uv ) was 24.8%.
  • Un-coupled linear tapered block copolymer D-(D/A)-A 1 accounted for 15.6% of total block copolymer molecular weight distribution as determined by GPC-RI.
  • Total styrene repeat unit content of the dual composition block copolymer was 39.8 wt.
  • Un-coupled tapered block copolymer was recovered by steam stripping and oven drying.
  • Weight average molecular weight (M w ) of the un-coupled tapered block copolymer synthesized was 93.2 kg/mol.
  • Molecular weight distribution exhibited a polydispersity index of 1.03, with a single narrow peak corresponding to an un-coupled linear tapered block copolymer of formula D-(D/A)-A.
  • Total styrene repeat unit content of the un-coupled tapered block copolymer was 40.5 wt.
  • Tan delta of dual composition block copolymer revealed predominately viscous behavior (Tan delta greater than 1.00) in the frequency range from 0.84 to 25 rad/s, exhibiting a maximum Tan delta of 1.36 at 5.0 rad/s. Details of rheological characterization of this un-coupled tapered block copolymer are shown in Table 3.
  • Coupled tapered block copolymer content (% C ri ) accounted for 34.5% of the total molecular weight distribution of the partially coupled tapered block copolymer, as determined by GPC-RI.
  • Monovinyl aromatic repeat unit weighted coupling level obtained by GPC-UV (% C uv ) was 35.5%, which very well matched the coupling level obtained by GPC-RI, as result of same monovinyl aromatic repeat unit content of un-coupled and coupled fractions.
  • Total styrene repeat unit content of the partially coupled tapered block copolymer was 42.2 wt. %, whereas its block styrene content was 31.6 wt %. Therefore, monovinyl aromatic repeat unit blockiness degree was 74.7 mole %.
  • Specific GPC and NMR characterization of this partially coupled tapered block copolymer is depicted in Table 2.
  • Total styrene repeat unit content of the un-coupled tapered block copolymer was 38.9 wt %, whereas block styrene content was 28.8%. Therefore, monovinyl aromatic repeat unit blockiness degree was 74.0 mole %.
  • Specific GPC and NMR characterization of this un-coupled tapered block copolymers is depicted in Table 2.
  • Complex dynamic shear viscosity of the un-coupled tapered block copolymer at 0.99 rad/s was 96249 Pa-s and dropped to 6269 Pa-s when evaluated at oscillating frequency of 100 rad/s.
  • Mooney viscosity of the un-coupled tapered block copolymer (ML1+4 at 100° C.) was 53.1.
  • Tan delta of dual composition block copolymer revealed predominately viscous behavior (Tan delta greater than 1.00) in the frequency range from 0.25 to 5 rad/s, exhibiting a maximum Tan delta of 1.17 at 0.99 rad/s. Details of rheological characterization of this un-coupled tapered block copolymer are shown in Table 3.
  • Formulation and block polymerization conditions EX-1 EX-2 EX-3 C-1 EX-4 C-2 EX-5 C-3 Cyclohexane, 0.896 0.896 71.48 71.56 71.36 71.41 71.37 71.46 kg First styrene 0.042 0.042 1.63 4.32 1.65 4.36 1.64 4.31 load, kg Butadiene, kg 0.105 0.105 6.62 6.64 6.62 6.63 6.63 6.64 n-butyllithium, 2.845 2.787 275.5 286.6 279.3 285.5 273.0 264.4 mmoles Polymerization 74.0 74.2 56.0 50.5 57.3 51.5 56.4 48.8 initial temperature, ° C.
  • Block copolymer GPC and NMR characterization Block copolymer GPC-NMR characterization EX-1 EX-2 EX-3 C-1 EX-4 C-2 EX-5 C-3 EX-6 M w by GPC-RI 169.8 171.8 147.4 93.2 151.5 160.1 170.2 107.8 147.8 Polydispersity 1.26 1.19 1.28 1.03 1.32 1.39 1.29 1.03 1.24 index by GPC-RI % C ri 27.4 25.5 35.4 — 32.9 34.5 35.8 — 36.9 % C uv 22.0 N.A. 21.8 — 21.5 35.5 23.6 — N.A.
  • the batch synthesis process performed in invention examples 1 thru 13 renders dual composition block copolymers, each with at least two distinguishable fractions of differing molecular weights and monovinyl aromatic repeat unit contents, where the fraction with lower molecular weight has greater monovinyl aromatic repeat unit content than the fraction exhibiting higher molecular weight.
  • FIG. 1 A comparison of molecular weight distributions of dual composition block copolymers prepared in Invention Examples 4 and 13, and in Comparative Example 2, prepared in batch reactor, and the commercial reference Buna BL30-4548, which has unimodal but very wide molecular weight distribution, typical of block copolymers prepared by prior art process in continuous polymerization reactor, is presented in FIG. 1 .
  • linear tapered block copolymers according to the prior art exhibit predominantly viscous behavior in a significant wide portion of the spectrum of frequencies evaluated, as revealed by tan delta values above 1.0.
  • a similar tan delta profile revealing predominantly viscous behavior in a portion of the frequency spectrum swept, is exhibited by the coupled tapered block copolymer of homogenous monovinyl aromatic repeat unit composition and medium viscosity level prepared in Comparative Example 2.
  • polymeric materials with predominantly elastic behavior i.e. with tan delta values below 1.0, are better suited for foaming application, because of their higher melt strength during the blowing process.
  • dual composition block copolymers can have a tri-modal molecular weight distribution.
  • uncoupled block copolymer fraction U is composed of tapered linear block copolymer molecules of formula D-(D/A)-A 1 , accounting for about 15.6% of the molecular weight distribution, and tapered linear block copolymer molecules of formula D-(D/A)-A 2 , accounting to about 47.0 wt % of the molecular weight distribution, where monovinyl aromatic blocks A 2 have greater molecular weight than monovinyl aromatic blocks A 1 .
  • the dual composition block copolymer prepared in Invention Example 13 exhibits tan delta values below 1.0 across the whole frequency range evaluated.
  • the crosslinked microcellular rubber probes were visually inspected to qualify surface appearance, they were also measured before and after crosslinking stage to ascertain volumetric shrinkage. In addition to this, the probes were analyzed by the following aspects:
  • Density was measured using an electronic densimeter, of MUVER brand, model 5085-2, under ISO 2781 standard method. Number average cell size and cell size standard deviation were measured by epi-fluorescence microscopy, using a Carl Zeiss AXIOTECH 100HD microscope and digital image analysis. Hardness was measured using a Bareiss brand Shore A durometer complying with DIN 53505 and ISO 868 standards, mounted on a MUVER 5019 holder. Resilience was measured using a Zwick 5109 Rebound resilience tester.
  • a rubber compound was prepared by compounding 100 phr of dual composition block copolymer prepared in Invention Example 3, 6 phr of azodicarbonamide as foaming agent (Celogen AZ-130) and 1.1 phr of dicumyl peroxide as crosslinking agent in a roll mill.
  • the rubber compound was compression molded, charging 3% excess to assure sealing of the mold.
  • the mold was clamped with heated plates at 150° C., under a clamping pressure of 92.8 kgf/cm 2 for 3 minutes. Thereafter, the mold was cooled down to 120° C. while keeping it pressurized. Then, the clamping pressure over the mold was released and compression press plates were opened. Immediate foam expansion occurred, which could be noticed from lifting of upper mold plaque.
  • Pre-crosslinked foamed probe was quenched in water at 23° C.
  • Crosslinking was completed by placing the pre-crosslinked foamed probe in a forced convection oven at 100° C. for 6 hours. Then rubber foam probe was conditioned for 24 hours at 23° C.
  • Crosslinked microcellular foamed rubber probes prepared in this way had smooth surface, without blister defects. Volumetric shrinkage by comparing pre-crosslinked and fully crosslinked probe volumes was 3.9%.
  • the crosslinked microcellular rubber probe had a density of 0.446 g/cm 3 , number average cell size of 6.74 microns, with a cell size standard deviation of 2.09 microns, Shore A hardness of 28.0, and a resilience of 37.9%.
  • Crosslinked microcellular rubber probe formulation and evaluation results are compared with the rest of the invention and comparative examples in Table 4.
  • a rubber compound and cross-linked microcellular rubber probe were prepared as in Invention Example 14, but comprising dual composition block copolymer prepared in Invention Example 4.
  • Crosslinked microcellular rubber probe prepared in this way had smooth surface, without blister defects. Volumetric shrinkage by comparing pre-crosslinked and fully crosslinked probe volume was 3.9%.
  • the crosslinked microcellular probe had density of 0.464 g/cm 3 , number average cell size of 8.08 microns, with a cell size standard deviation of 2.40 microns, Shore A hardness of 38, and a resilience of 37.9%.
  • Crosslinked microcellular rubber probe formulation and evaluation results are compared with the rest of the invention and comparative examples in Table 4.
  • a rubber compound and cross-linked microcellular rubber probe were prepared as in Example 14, but comprising dual composition block copolymer prepared in Invention Example 5.
  • Crosslinked microcellular rubber probe prepared in this way had smooth surface, without blister defects. Volumetric shrinkage by comparing pre-crosslinked and fully crosslinked probe volume was 4.0%.
  • the crosslinked microcellular probe density of 0.662 g/cm 3 , Shore A hardness of 38.0, and a resilience of 37.0%.
  • Crosslinked microcellular rubber probe formulation and evaluation results are compared with the rest of the invention and comparative examples in Table 4.
  • a rubber compound and cross-linked microcellular rubber probe were prepared as in Invention Example 14, but comprising the prior art un-coupled tapered block copolymer prepared in Comparative Example C-1.
  • Crosslinked microcellular foamed rubber probe prepared in this way had irregular surface, with blister defects. Volumetric shrinkage by comparing pre-crosslinked and fully crosslinked probe volume was 3.9%.
  • the crosslinked microcellular rubber probe had density of 0.526 g/cm 3 , number average cell size of 13.1 microns, with a cell size standard deviation of 8.79 microns, Shore A hardness of 55.0, and a resilience of 28.2%.
  • Crosslinked microcellular rubber probe formulation and evaluation results are compared with the rest of the invention and comparative examples in Table 4.
  • a rubber compound and cross-linked microcellular rubber probe were prepared as in Invention Example 14, but comprising prior art coupled tapered block copolymer prepared in Comparative Example C-2.
  • Crosslinked microcellular rubber probe prepared in this way had an irregular surface, with blister defects. Volumetric shrinkage by comparing pre-crosslinked and fully crosslinked probe volume was 4.0%.
  • the crosslinked microcellular rubber probe had density of 0.790 g/cm 3 , number average cell size of 9.50 microns, with a cell size standard deviation of 3.38 microns, Shore A hardness of 76.0, and a resilience of 31.0%.
  • Crosslinked microcellular rubber probe formulation and evaluation results are compared with the rest of the invention and comparative examples in Table 4.
  • a rubber compound and cross-linked microcellular rubber probe were prepared as in Invention Example 14, but comprising prior art un-coupled tapered block copolymer prepared in Comparative Example C-3.
  • Crosslinked microcellular rubber probe prepared in this way had irregular surface, with blister defects. Volumetric shrinkage by comparing pre-crosslinked and fully crosslinked probe volume was 3.9%.
  • the crosslinked microcellular rubber probe had density of 0.694 g/cm 3 , number average cell size of 6.40 microns, with a cell size standard deviation of 2.00 microns, Shore A hardness of 53, and a resilience of 32.8%.
  • Crosslinked microcellular rubber probe formulation and evaluation results are compared with the rest of the invention and comparative examples in Table 4.
  • a rubber compound and cross-linked microcellular rubber probe was attempted to be prepared as in Example 14, but comprising prior art block copolymer Buna BL30-4548 (from ARLANXEO, block copolymer with unimodal and very wide molecular weight distribution shown in FIG. 1 , commercial reference for microcellular rubber application), instead of dual composition block copolymer.
  • block copolymer Buna BL30-4548 from ARLANXEO, block copolymer with unimodal and very wide molecular weight distribution shown in FIG. 1 , commercial reference for microcellular rubber application
  • compression molding, mold cooling, depressurization and mold opening conditions prevailed exactly as in Invention Example 14, when load pressure over the hot mold was released and press plates were opened, rubber compound expansion occurred to a very limited extent, as lifting of the mold upper plaque could not be noticed.
  • Crosslinked rubber probe prepared in this way had smooth surface, without blister defects. Volumetric shrinkage by comparing pre-crosslinked and fully crosslinked probe volume was 0%.
  • the crosslinked rubber probe had a very high density of 1.042 g/cm 3 , which evidenced poor foaming performance of this rubber compound.
  • Optical microscopy analysis revealed very scarce cell counts, with a number average cell size of 14.25 microns, with a cell size standard deviation of 5.04 microns.
  • the crosslinked rubber probe had a Shore A hardness of 43, and a resilience of 37.5%.
  • Crosslinked rubber probe formulation and evaluation results are compared with the rest of the invention and comparative examples in Table 4.
  • the block copolymers employed in the formulation had very similar Mooney viscosity values, 32.0 and 32.4, respectively, and very similar complex shear viscosity profiles at 100° C., as can be reviewed in Table 3 (see Invention Example 3 and Comparative Example C-1). It can be noticed that usage of invention dual composition block copolymer in the rubber compound formulation in Invention Example 14 conducted to produce crosslinked microcellular rubber probe with smoother surface, with lower density, with smaller and more homogeneously sized cells, with lower hardness and higher resilience than when performing formulation than when using prior art uncoupled tapered block copolymer in Comparative Example C-4. Low volumetric shrinkage was obtained for both Invention Example 14 and Comparative Example C-4.
  • the block copolymers employed in the formulation had very similar Mooney viscosity values, 39.2 and 40.6, respectively, and very similar complex shear viscosity profiles at 100° C., as can be reviewed in Table 3 (see Invention Example 4 and Comparative Example C-2). It can be noticed that usage of invention dual composition block copolymer in the rubber compound formulation in Invention Example 15 conducted to produce crosslinked microcellular rubber probe with smoother surface, with lower density, with smaller and more homogeneously sized cells, with much lower hardness and higher resilience than when performing formulation using prior art coupled tapered block copolymer in Comparative Example C-5. Low volumetric shrinkage was obtained for both Invention Example 15 and Comparative Example C-5.
  • the block copolymers employed in the formulation had very similar complex shear viscosity profiles at 100° C., as can be reviewed in Table 3 (see Invention Example 3 and Comparative Example C-1). It can be noticed that usage of invention dual composition block copolymer in the rubber compound formulation in Invention Example 16 conducted to produce crosslinked microcellular rubber probe with smoother surface, with lower density, with lower hardness and higher resilience than when performing formulation than when using prior art uncoupled tapered block copolymer in Comparative Example C-6. Low volumetric shrinkage was obtained for both Invention Example 16 and Comparative Example C-6.
  • a foamable rubber compound was prepared by compounding 100 phr of dual composition block copolymer of Example 13, 6 phr of azodicarbonamide and 1.1 phr of dicumyl peroxide in a roll mill.
  • the foamable rubber compound was compression molded, charging 3% rubber compound excess to assure sealing of the mold.
  • the mold was clamped with heated plates at 170° C., under a clamping pressure of 92.8 kgf/cm 2 for 3 minutes. Then the pressure load over the mold was released and compression press plates were opened. Immediate foam expansion occurred, which could be noticed from lifting of upper mold plaque. Then, the mold and the crosslinked microcellular rubber probe were quenched in water at 23° C.
  • the crosslinked microcellular rubber probe was taken out of the mold and dried with absorbing paper. The crosslinked microcellular rubber probe was then conditioned in controlled atmosphere room at 23° C. and 50% relative humidity for 7 days.
  • the crosslinked microcellular rubber probe prepared in this way had smooth surface, without blister defects. It had density of 0.624 g/cm 3 , and exhibited 0% shrinkage after the 7 days of conditioning in controlled atmosphere room; Formulation and properties of crosslinked microcellular rubber compound are summarized in Table 5.
  • a foamable rubber compound and a cross-linked microcellular rubber probe were prepared as in Invention Example 17, but comprising Buna® BL30-4548, instead of dual composition block copolymer.
  • compression molding conditions prevailed exactly as in Invention Example 17, when load pressure over the hot mold was released and compression press plates were opened, rubber compound foam expansion occurred to a very limited extent, as lifting of the mold upper plaque could not be noticed.
  • the crosslinked microcellular foamed rubber probe prepared in this way had smooth surface, without blister defects; Its density of 0.986 g/cm 3 revealed low foaming performance of this compound.
  • Formulation and properties of crosslinked microcellular rubber compound are summarized in Table 5.
  • compounding evaluations were performed in a laboratory internal mixer.
  • the formulations contained either dual composition block copolymers of the invention or prior art tapered block copolymers. Torque and temperature readings were collected to assess the compounding performance.
  • the compounding evaluations were performed in an Intelli-Torque Plasti-Corder, equipped with Prep-Mixer measuring head, with CAM blades and net chamber volume of 420 ml, from Brabender brand.
  • the standard formulation employed also comprised emulsion SBR, fillers, plasticizers, antioxidant, chemical blowing agent, blowing agent activator, crosslinking agent, crosslinking accelerator, crosslinking agent activator.
  • a compounding evaluation was performed in a laboratory internal mixer.
  • Initial charge comprised 80 phr of dual composition block copolymer prepared in Example 3 and 20 phr Emulprene 1502 (cold emulsion styrene-butadiene random copolymer with 23.5% styrene repeat unit content, from Dynasol Group), mixing started with chamber temperature stabilized at 45° C. At a mixing time of 1 minute, 2.5 phr of naphthenic oil and 1.7 phr of paraffin wax were added.
  • the block copolymers employed in the formulation had very similar Mooney viscosity values, 39.2, 39.0 and 40.6, respectively, and very similar complex shear viscosity profiles at 100° C., as can be reviewed in Table 3 (see Invention Example 4, Invention Example 13 and Comparative Example 2). Again, it can be noticed that at the end of the compounding cycle slightly lower torque and lower chamber temperature was obtained when formulation comprised dual composition block copolymer than when comprising prior art uncoupled tapered block copolymer.
  • Slightly lower torque when compounding formulations comprising dual composition block copolymers of the invention represent an advantage as lower power consumption is needed to conduct compounding operation.
  • Slightly lower final internal chamber temperature when compounding formulations comprising dual composition block copolymers of the invention represent an advantage as premature crosslinking and premature blowing problems during mixing operation are better avoided; this is particularly advantageous when using crosslinking systems and/or blowing agent systems with low activation temperatures.
  • hot-melt pressure sensitive adhesives comprising a dual composition block copolymer of the present invention or prior art block copolymers.
  • the formulation employed was customized for label adhesive purpose. Properties of the adhesives were evaluated with the following test methods: Brookfield viscosity at 150, 160 and 177° C., by ASTM D1084/D2556; ring and ball softening point temperature, was obtained by ASTM D36; loop tack tests at 23° C. were conducted according to PSTC-16; Rolling Ball Tack was evaluated at 23° C. as normed by PSTC-6; peel strength at 180° angle and 23° C. as per PSTC-1; and shear strength at 23° C. with ASTM D3654.
  • Formulation was carried out in a 500 ml cylindric metal container equipped with controlled heating mantle and adjustable stirring speed by a three-blade propeller.
  • Tackifier, naphthenic oil and antioxidant were first heated at 135° C. under nitrogen atmosphere and gentle stirring to melt the components.
  • stirring speed was set at 300 RPM and temperature was raised to 155° C., over a 30-minutes period.
  • dual composition block copolymer was gradually added and stirring speed was increased to 750 RPM.
  • temperature was controlled at 170 ⁇ 5° C. for the following 2 hours, while stirring at 750 RPM to assure homogenization of the formulation.
  • This adhesive exhibited Brookfield viscosities of 66300 cP at 150° C., of 46380 cP at 160° C., and of 19680 cP at 177° C.; ring and ball softening point temperature of 90.9° C.; loop tack at 23° C. of 8.853 lb f -in, rolling ball tack at 23° C. of 0.28 in; peel strength at 180° angle and 23° C. of 4.04 lb f ; and shear strength at 23° C. of 9.58 minutes with a load of 1000 g.
  • Formulation and performance of the adhesive are shown in Table 7.
  • a hot-melt pressure sensitive adhesive for label was prepared as in Invention Example 22, but replacing Dual Composition Block Copolymer by Solprene® 1205, from Dynasol Group.
  • Solprene® 1205 is a tapered styrene-butadiene block copolymer with total styrene content of 25 wt. %, block styrene content of 17.5 wt. %, and Mooney viscosity ML 1+4 at 100° C. of 47, which is a well-established benchmark for the formulation of hot-melt pressure sensitive adhesives.
  • This adhesive performed Brookfield viscosities of 14000 cP at 150° C., of 10750 cP at 160° C., and of 7050 cP at 177° C.; ring and ball softening point temperature of 69.95° C.; loop tack at 23° C. of 6.132 lb f -in; rolling ball tack at 23° C. of 0.44 in; peel strength at 180° angle and 23° C. of 3.275 lb f ; and shear strength at 23° C. of 1.55 minutes at 1000 g load. Recipe and properties of this adhesive are listed in Table 7.
  • a hot-melt pressure sensitive adhesive for label was prepared as in Invention Example 22, but replacing Dual Composition Block Copolymer by Calprene® 540, from Dynasol Group.
  • Calprene® 540 is linear styrene-butadiene-styrene triblock copolymer with total styrene content of 40 wt. %, block styrene content of 38 wt. %, which is also marketed for the formulation of hot-melt pressure sensitive adhesives.
  • This adhesive presented Brookfield viscosities of 13260 cP at 150° C., of 9300 cP at 160° C., and of 5470 cP at 177° C.; ring and ball softening point temperature of 85.3° C.; loop tack at 23° C. of 5.05 lb f -in; rolling ball tack at 23° C. of 0.98 in; peel strength at 180° angle and 23° C. of 4.09 lb f ; and shear strength at 23° C. of 713.5 minutes at 1000 g load. Evaluation of this adhesive is shown in Table 7.
  • Hot-Melt Pressure Sensitive Adhesive EX-22 C-13 C-14 Adhesive Dual composition block 100 0 0 formulation copolymer, phr Solprene ® 1205, phr 0 100 0 Calprene ®, phr 0 0 100 Foral ® 85, phr 178 178 Nyflex ® 223, phr 50 50 50 Irganox ® 1010, phr 4 4 4 4 Adhesive Brookfield viscosity at 66300 14000 13206 performance 150° C., cP Brookfield viscosity at 46380 10750 9300 160° C., cP Brookfield viscosity at 19680 7050 5470 177° C., cP Ring and ball softening 90.9 69.95 85.3 temperature, ° C.
  • Performance evaluation of hot-melt pressure sensitive adhesive formulation for labels shows that dual composition block copolymer confers outstanding tack, which may be related to higher wetting and adherence capacity of terminal conjugated diene rich blocks of its coupled fraction.
  • the higher softening point temperature of the adhesive formulated with dual composition block copolymer can be advantageous to expand service temperature range of the adhesive, as to be useful for labels of merchandises exposed to high temperatures during their transportation. Brookfield viscosity of hot melt adhesive according to the invention is at the upper limit of usefulness for its processing, nevertheless it may be easily lowered by proper adjustment of molecular parameters such as molecular weight, coupling level, and/or functionality of coupling agent employed.
  • the primary anticipated end-use application for the dual composition block copolymers of the present invention is in making the crosslinked microcellular rubber articles described herein.
  • the dual composition block copolymers of the present invention may also be useful in asphalt reinforcement, adhesives, sealants, coatings, insulation and plastic compositions. End-use applications for block copolymers are described in U.S. patent application Ser. No. 15/417,193, filed on Jan. 26, 2107, and published on Jul. 27, 2017, as U.S. Pub. No. 2017/0210841 A1, which is incorporated by reference.
  • bituminous composition that can include a bitumen; one or more additives selected from the group consisting of plasticizers; fillers; crosslinking agents; flow resins; tackifying resins; processing aids; antiozonants; and antioxidants; and a dual composition block copolymer composition as described and claimed herein, wherein the bituminous composition includes from about 0.5 to about 25 percent weight, preferably from about 0.5 to about 8 percent weight for road paving applications and 3 to about 25 percent weight for roofing, shingles and waterproofing membrane applications.
  • the bituminous composition can also be emulsified in water with an emulsifying agent.
  • One application is an adhesive composition that can include at least one additive selected from the group consisting of tackifying resins; plasticizers; solvent; coupling agents; crosslinking agents; photoinitiators; and antioxidants; and a dual composition block copolymer composition as described and claimed herein, wherein the adhesive composition includes from about 0.5 to about 50 percent weight of the dual composition block copolymer composition.
  • Another application is a sealant composition that can include at least one additive selected from the group consisting of tackifying resins; plasticizers; fillers; coupling agents; processing aids; and antioxidants; and a dual composition block copolymer composition as described and claimed herein, wherein the sealant composition includes from about 0.5 to about 50 percent weight of the dual composition block copolymer composition.
  • Another suitable application of the invention is the production of high impact styrenic resins, such as HIPS and ABS obtained by bulk polymerization of styrene, or bulk copolymerization of styrene and acrylonitrile, in the presence dual composition block copolymer, for the specific purpose of improving gloss with minimal compromise of impact strength, which can include a mixture of a polymeric composition and a dual composition block copolymer composition as described and claimed herein.
  • HIPS and ABS high impact styrenic resins, such as HIPS and ABS obtained by bulk polymerization of styrene, or bulk copolymerization of styrene and acrylonitrile

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MX2021004587A MX2021004587A (es) 2018-12-20 2019-12-10 Copolimeros de bloque de composicion doble.
ES19899386T ES2966215T3 (es) 2018-12-20 2019-12-10 Copolímeros de bloques de doble composición
CA3115790A CA3115790C (en) 2018-12-20 2019-12-10 Dual composition block copolymers
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PL19899386.7T PL3853274T3 (pl) 2018-12-20 2019-12-10 Kopolimery blokowe o podwójnym składzie
PCT/IB2019/001434 WO2020128635A2 (en) 2018-12-20 2019-12-10 Dual composition block copolymers
EP23206980.7A EP4324880A3 (en) 2018-12-20 2019-12-10 Dual composition block copolymers
JP2021523842A JP2022506453A (ja) 2018-12-20 2019-12-10 二組成ブロックコポリマー
BR112021006532-6A BR112021006532B1 (pt) 2018-12-20 2019-12-10 Composição de copolímero em bloco e seus processos de fabricação, composições para um artigo de borracha, para um adesivo sensível à pressão de fusão à quente, composições adesiva, vedante e betuminosa, e resina de poliestireno de alto impacto, e resina abs
CN202310295514.3A CN116217844A (zh) 2018-12-20 2019-12-10 双组分嵌段共聚物
EP19899386.7A EP3853274B1 (en) 2018-12-20 2019-12-10 Dual composition block copolymers
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