Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/16—Homopolymers or copolymers of alkyl-substituted styrenes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
  • C08L51/04—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to rubbers

Definitions

• This invention pertains to improved poly- blends which are an admixed product of a copolymer of styrene and a-methylstyrene with a grafted interpoly- merizate of polystyrene on an elastomeric polybutadiene substrate or backbone.
• thermo ⁇ plastic polymerizates and/or polyblends of the prior art have acceptable tensile strengths, impact resis ⁇ tances and heat distortion values. However, they are often found to have less than desirable degrees of other significant properties such as and including thermal stability, hardness and environmental stress crack resistance; especially when the plastics are prepared from conventional interpolymerizates of styrene, including the polyblends of various styrene polymers with differing rubber-modifiers.
• the present invention is an impact resistant and heat distortion resistant and tough polyblend composition that is comprised of an admixture of:
• Ar is an aromatic radical
• Ar is an aromatic radical; said copolymer containing 10 to 70 mole percent based on total copolymer weight of at least one copolymerized monomer of said Formula (I); and (B) 5 to 60 percent by weight based on total weight of the polyblend of a graft-copolymer, grafted rubber concentrate material dispersed in Component (A) in the form of particles having a core/shell structure comprised of:
• G is hydrogen or methyl and Ar is an aromatic radical; said interpolymer (b') being formed upon a substrate or backbone core portion of said graft-copolymer of:
• Component (b) 90 to 25 weight percent based on total weight of Component (B) of an elastomeric, graftable rubber which provides the core in said grafted rubber concentrate material of said Component (B).
• the polyblends according to the invention contain 40 to 95 percent by weight based on the total weight of the polyblend of Component A.
• the polyblends in accordance with the present invention contain 60 to 90 percent by weight of Component (A), more preferably 60 weight percent.
• the isopropenyl aromatic monomers utilizable in the preparation of the copolymer Component (A) in the polyblends of the invention are of the Formula:
• Ar is an aromatic radical (including various alkyl- and halo-ring-substituted aromatic units) of from 6 to 10 carbon atoms.
• the preferable monomer of the Formula (I) is or-methylstyrene although such specific varieties as isopropenyltoluene and isopropenylnaph- thalene may also be utilized.
• Formula (I) monomers in mixtures may be employed.
• Styrene is generally preferred as the vinyl aromatic Formula II monomer employed for copolymeri- zation with the Formula (I) monomers for preparation of the Component (A) constitutent.
• the monomeric materials which may be utilized in various mixtures with one another are of the Formula II:
• Ar is an aromatic radical of the same defi ⁇ nition as employed in the description of Formula (I).
• Species of Formula (II) monomers besides styrene that may, be employed include: vinyltoluene; vinylnaph- thalene, the dimethylstyrenes; t-butylstyrene; the several chlorostyrenes (such as the mono- and dichloro- variants); and the several bromostyrenes (such as the mono-and dibromo-variants) .
• the (A) component has compoly- merized therein 10 to 70 mole percent of at least one Formula I monomer(s) and 90 to 30 mole percent Formula II monomer(s). It is often advantageous for the Formula (I)/Formula (II) copolymers employed as the Component
• (A) constituents in the polyblends of the present invention to contain 20 to 70 weight percent of copoly ⁇ merized Formula (I) monomer. It is frequently pre ⁇ ferred for this proportion of the copolymerized Formula (I) monomer to be 50 to 70 weight percent.
• the heat distortion characteristics are substantially improved as the proportion of the Formula (I) monomer in the copolymers used as the Component (A) constituents is increased; particularly when ⁇ -methylstyrene is the included comonomer and especially so when such copolymer is comprised substantially of copolymerized ⁇ -methylstyrene and styrene.
• the Formula (I)/Formula (II) copolymers perform well when their weight average molecular weight (M W) is in the range of from 50,000 to 500,000, with associated molecular weight distribution values of 1 to 3. There is usually achieved a most beneficial effect when the Component (A) copolymers have M W values in the range between 100,000 and 200,000 with M distribution values of 1 to 2.5.
• M W weight average molecular weight
• constituents of the polyblended compositions of the invention preferably have a core portion of normally- solid, elastomer.
• Any elastomeric material that can be obtained in emulsion or latex form is suitable for use in the present invention.
• Such elastomeric material may be prepared by free radical polymerization in an emulsion or alternatively an elastomer is dissolved in a solvent, the solution mechanically emulsified, agglomer ⁇ ated and grafted as described by component (B).
• Some such elastomers include butadiene polymers, isoprene polymers, acrylate polymers, ethylene propylene copoly ⁇ mers with a diene.
• Such elastomers include copolymers and terpolymers employing materials such as styrene, acrylonitrile and the like. Other of the rubbers and elastomers are disclosed in U.S. Patent 4,371,663.
• the synthetic rubber involved is a polymer or copolymer (besides polybutadiene) of butadiene-1,3 and/or isoprene and/or 2,3-dimethyl- butadiene-1,3.
• the polyblends according to the invention generally contain 5 to 60 percent by weight based on the total weight.of the polyblend of Component (B), more preferably 40 percent by weight.
• the shell portion of the grafted rubber concentrates included in the Component (B) is preferably interpolymerized poly ⁇ styrene grafted upon the substrate backbone elastomeric core.
• the shell portion of the grafted rubber concen ⁇ trate (b' ) is generally from 10 to 75 weight percent of the grafted rubber concentrate.
• the shell portion of the grafted rubber concentrate it is often times of greater advantage for the shell portion of the grafted rubber concentrate to be between 20 and 30 weight percent of the graft-interpolymerized component; with optimum benefit often being when the shell portion is 25 weight percent of the grafted rubber concentrate material (within ⁇ 3 weight percent) .
• grafted rubber concentrate materials used for the Component (B) in polyblends of the present invention it is usually desirable for the individual particles (whether monodisperse or polydisperse to be relatively large such as in the range of from 0.05 to 3 microns ( ⁇ ); more frequently to be 0.3 ⁇ to 2 ⁇ .
• a latex of a polymer of 10 weight per ⁇ cent acrylic acid and 90 weight percent ethyl acrylate is utilized as an agglomerating agent, generally not more than 0.4 parts by weight based on solids of material is utilized per 100 parts of the elastomer to be agglom ⁇ erated.
• a shell/core agglomerating agent has been found to be of better properties than the acrylic acid acrylate combination.
• the shell/core agglomerating agent contains a shell of about 8 weight percent methacrylic acid and 92 percent ethyl acrylate and about 2 parts of the agent are used for 100 parts of the elastomer to be agglomerated. In both cases, 30 to 50 weight percent of the original elastomer having a particle diameter of 0.1 micron is agglomerated to a size of 0.3 to 2.5 microns.
• Isopropenyl aromatic monomers of the Formula (I), particularly ⁇ -methylstyrene, are difficult and sometimes impossible to polymerize by thermal or free- radical-catalyst-initiated polymerization whether done in mass or by solution or suspension polymerization. Such difficulty is also experienced when conventional polymerizing techniques are used to make random copoly ⁇ mers and/or graft copolymers of isopropenyl aromatic monomers with other mono- or ethylenicallyunsaturated monomers and polymers which normally are readily polymer- izable by thermal or free-radical mechanisms.
• the indicated copolymers and graft copolymers of component A, utilizing ⁇ -methylstyrene and/or other Formula (I) monomers are readily made by anionic, solution polymerization using an organometallic initiator, such as sec-butyl-lithium, n-butyl-lithium as in U.S. Patents Nos. 3,322,734 and 3,404,134.
• organometallic initiator such as sec-butyl-lithium, n-butyl-lithium as in U.S. Patents Nos. 3,322,734 and 3,404,134.
• a good procedure for co- and interpolymerization of isopropenyl aromatic monomers is as disclosed in EPO Publication 135,168.
• the desired proportions or Components (A) and (B) are physically admixed to provide a mixture which appears homogeneous to the unaided eye.
• any suitable plastics compounding apparatus may be employed. Batch- wise blendings may be done using such equipment as a Brabender "PLAS ICORDER” (Reg. TM); while continuous blending may be made with ordinary extruders, including twin-screw extruders.
• the poly- blends are prepared by melt blending of the Components (A) and (B) by mechanical admixture thereof on or in intensive compounding equipment (such as, extruders; compounding rolls, and Banbury mixers) at a temperature adequate to heat plastify the components being mixed but lower than that which might cause significant polymer decomposition thereof. If the polymers are in latex form, the latexes can be blended, the blend coagulated and dried to recover the polymer.
• the polyblended products of the present invention can contain other additives that are often ⁇ times utilized in plastics compositions, such as anti- oxidants; pigments; dyes; fillers; stabilizers; mineral oil and other plasticizers and lubricants; and blowing agents.
• additives that are often ⁇ times utilized in plastics compositions, such as anti- oxidants; pigments; dyes; fillers; stabilizers; mineral oil and other plasticizers and lubricants; and blowing agents.
• the polyblends of the present invention have a combination of very good toughness with high heat distortion values.
• Table I a typical polyblend pursuant to the present invention surpri ⁇ singly exhibits good heat distortion while still main- taining high tensile strength and acceptable impact resistance.
• the tensile strengths are given in mega pascals (MPa) and in pounds per square inch (psi).
• the Izod impact strengths are given in Joules per meter of notch (J/m) and foot pounds per inch of notch (ft-lb/in.)
• the heat distortion values are given in degrees Celsius (°C) and farenheit (°F).
• the gloss is given in percent
• a typical rubber-modified high-impact polystyrene plastic composition made with about 5 weight percent of polybutadiene.
• ABS product of polymerized acrylo- nitrile/butadiene/styrene having a rubber content of about 13.5 weight percent with a soluble fraction containing about 23.5 weight percent acrylo- nitrile, the product having properties about equivalent to such commercially available ABS resins.
• the polyblends of the present invention are useful for heat fabrication (by injection and com ⁇ pression molding, extrusion, thermoforming and the like) into articles that are both tough and withstand higher service temperatures.
• Such applications include hot-fill containers, dishes, cups, reusable containers for microwave heating and/or cooking; electronic com ⁇ ponent parts; television cabinets; automotive parts and like uses where high temperature performance is desir ⁇ able.
• Shaped articles produced from polyblends in accordance with the present invention can be made to have an attractive attractive smooth and glossy surface which cleans readily when subjected to ordinary washing procedures. They are also readily paintable and weldable.
• a grafted rubber concentrate of the "shell/core" type of graft copolymer of a polystyrene shell portion on a polybutadiene core was prepared in the following manner. Minor proportions of monomeric materials other than styrene and butadiene were employed. These materials were used for the preparation of an agglom ⁇ erating agent used to produce relatively large-sized and largely monodispersed particles of the poly ⁇ butadiene core backbone.
• the steps involved include:
• the preparation of the agglomerating agent was done in a 0.76 cubic meter (200 U.S. gallon) glass-lined jacketed Pfaudler kettle equipped with an agitator. The following mixtures were prepared. All numerical weight quantities are indicated kilograms (kg) and the quantity in pounds is given in parenthesis:
• the reactor charge (1) was added to the
• the grafted rubber con ⁇ centrate material for preparation of polyblends in accordance with the present invention, a second set of preformulated mixtures was prepared most being in the form of aqueous solutions or dispersions where the below-indicated percent activity or percent solids concentrations were used.
• Manufacture of the grafted rubber concentrate material was done in a 13.25 cubic meters (3,500 U.S. gallon) glass lined jacketed reactor. The mixtures used were as follows where quantities are in kilograms and (pounds):
• Butadiene 253 (557.5) 8 2020 (4,460) n-Dodecylmercaptan 105 (2.32) 7.75 8.2 (18) Aqueous Mix (5) 0.93 (2.06) 6 562 (1,238)
• the graft copolymerization reaction was allowed to proceed for an hour after completion of all above-indicated additions.
• the reactor contents were then cooled.
• the resulting grafted rubber concentrate converted from latex to a dry powder.
• a plurality of dried samples were prepared by a charging of 3.8 liters (1 U.S. gallon) of the grafted rubber concentrate latex into a steam-stripping unit, adding to the latex prior to the stripping about 3-5 grams of a commercial silicone antifoam agent obtained from Dow Corning Corporation of Midland, Michigan 48640, under the trade-designation "DOW CORNING FG-10".
• the steam stripping was continued until 350 ml of condensate had been collected. After that, 0.6 percent (based on the rubber content) of "TOPANOL CA" (Reg.
• TM Trimethyl TM
• TOPANOL CA 1,l,3-tris(2' methyl 4' hydroxy-5' tertiary-butyl phenyl) butane)
• 0.2 percent (also based on the involved rubber content) of dilaurylthiodipropanoate were added to each steam- stripped sample. The product was then freeze-coagulated, centrifuged and dried overnight at 50°.
• the resultant pulverulant grafted rubber concentrate material was used below in the preparation of polyblends according to the present invention.
• Experiment 2 Preparation of a Grafted Rubber Concentrate The general procedure of Experiment 1 was used to prepare a second grafted rubber concentrate.
• the grafted rubber concentrate material was employed in the manufacture of polyblend products pursuant to the invention.
• a 50:50 weight ratio copolymer of ⁇ -methyl- styrene and styrene was made by means of continuous anionic polymerization so as to have a 170,000 M W.
• Samples of polyblends with only the smaller particle size grafted rubber concentrates were then prepared in about the same homopolymer or copolymer (Component A) to grafted rubber concentrate (Component B) weight ratios as made in the Experiment 3 using in some, for comparative purposes, general purpose polystyrene in the mixtures and in the others ⁇ -methylstyrene/styrene copolymers.
• test specimens of second grafted rubber concentrate materials with no particle size inclusions greater than 1.8 ⁇ were compared with samples of analogous homopolystyrene and ⁇ -methylstyrene/styrene copolymer polyblends containing the first grafted rubber concentrate material as used in the Experiment 3 which had some of the 1.8 ⁇ and larger particles.
• the results are as set forth in Table III.
• the polyblends were formulated to contain 20 weight percent elastomer.
• graft rubber concentrate 2 in place of graft rubber concentrate 1, (substituting the smaller rubber particles) causes a loss of impact resistance in blends with general purpose polystyrene while similar substitutions in styrene alpha-methylstyrene blends result in substantial gain in impact resistance.
• the heat distortion values of polyblends prepared in accordance with the present invention are at least equal to and often greater than those pre ⁇ dictable from the components of homopolystyrene and/or ⁇ -methylstyrene/styrene copolymers when the latter are individually subjected to the same heat distortion testing.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Graft Or Block Polymers (AREA)

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• 1985
  • 1985-06-04 EP EP19850903126 patent/EP0185734A4/de not_active Withdrawn
  • 1985-06-04 CA CA000483089A patent/CA1231484A/en not_active Expired
  • 1985-06-04 AU AU44933/85A patent/AU570332B2/en not_active Ceased
  • 1985-06-04 BR BR8506767A patent/BR8506767A/pt not_active IP Right Cessation
  • 1985-06-04 KR KR1019860700073A patent/KR900002532B1/ko not_active IP Right Cessation
  • 1985-06-04 WO PCT/US1985/001055 patent/WO1986000082A1/en not_active Application Discontinuation

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