Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/36—Sulfur-, selenium-, or tellurium-containing compounds
  • C08K5/41—Compounds containing sulfur bound to oxygen
  • C08K5/42—Sulfonic acids; Derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/16—Nitrogen-containing compounds
  • C08K5/17—Amines; Quaternary ammonium compounds
  • C08K5/175—Amines; Quaternary ammonium compounds containing COOH-groups; Esters or salts thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/49—Phosphorus-containing compounds
  • C08K5/51—Phosphorus bound to oxygen
  • C08K5/53—Phosphorus bound to oxygen bound to oxygen and to carbon only
  • C08K5/5317—Phosphonic compounds, e.g. R—P(:O)(OR')2

Definitions

• the present invention relates to halogenated olefin polymers. More specifically, the invention relates to the vulcanization of chlorinated olefin polymers.
• Heavy metal compounds commonly are employed for a variety of reasons by compounders in the rubber industry.
• An example of a typical use for these compounds is the use of zinc stearate as a pre-cure anti-blocking agent in formulated rubber compounds.
• Zinc oxide commonly is used as part of the cure system in various grades of rubber compounds.
• the wide use of heavy metal compounds leaves trace amounts of these compounds in and on rubber processing equipment, such as Banbury mixers, conveyor belts, mills, cooling systems and extruders.
• Certain heavy metals are detrimental to the heat stability of certain cured halogenated olefin polymers, such as cured chlorinated polyethylene. Heat instability is evidenced by polymer degradation, a result of dehydrohalogenation catalyzed by the heavy metal compounds, and darkening. Trace metal contaminants, particularly zinc, interfere with the cross-linking mechanism of sulfur-donor cured chlorinated polyethylene formulations, subsequently reducing all physical properties of the cured compound. In custom rubber processing shops many different rubber formulations regularly are used. In these shops it is uneconomical and impractical, if not impossible, to clean the equipment between runs of different rubber formulations to ensure the absence of heavy metal compounds.
• chlorinated olefin polymer formulations When chlorinated olefin polymer formulations are prepared in these shops, it is common for the chlorinated olefin polymer to pick up trace amounts of heavy metals, thus adversely affecting the physical properties of the chlorinated olefin polymer formulation after it is vulcanized.
• the present invention resides in a process for improving the heat degradation resistance of heavy metal containing cured chlorinated olefin polymers and the state of cure consistency in sulfur donor cured chlorinated polyethylene, comprising the steps of contacting an uncured chlorinated olefin polymer formulation with a polyacid in an amount sufficient to reduce the heat-induced degradation of the formulation after it is cured.
• the present invention resides in an improved chlorinated olefin polymer composition
• the composition when cured, provides a polymer with an improved state of sulfur donor cure and resistance to heat degradation.
• the invention further resides in an improved chlorinated polyethylene composition
• an improved chlorinated polyethylene composition comprising a chlorinated polyethylene homopolymer or copolymer, a vulcanizing peroxide or sulfur donor curing agent, and ethylenediaminetetra-acetic acid, its disodium salt, its tetrasodium salt, or mixtures thereof to improve the state of sulfur donor cure and resistance of the cured composition to heat degradation.
• the polyacid is a stabilizer and, as used in this application, shall mean a compound having more than one acid group and capable of forming a 5 to 7 member coordinating ring for chelating heavy metals, and includes either carboxylic or phosphonic acid groups or both, their salts and aminopolyacids.
• a polyacid reduces the degradation-promoting effect of heavy metals on chlorinated olefin polymer- containing formulations.
• a stabilizing polyacid prevents the metal contaminants from interfering with the curing mechanism of sulfur donor cure systems.
• Cured chlorinated olefin polymer-containing compositions are useful for making manufactured articles such as, for example, automotive under-the-hood wire, tubing and hose; chemical transfer hose; sheet rubber goods; molded goods; belting; gasketing; flexible membranes and profiles; and jacketing of flexible cords and cable such as power, instrument and control cable, industrial power cable, heater cord and portable cord.
• the chlorinated olefin polymer employed in the present invention is a polymer prepared by the
• the olefin polymer is selected from polyethylene and interpolymers of ethylene and one or more ethylenically unsaturated comonomers, with ethylene making up at least 90 mole percent of the total monomer composition. It is preferred to employ
• 1-olefins as comonomers.
• preferred 1-olefin monomers include 1-butene and 1-octene.
• Suitable chlorinated olefin polymers have a weight average molecular weight of at least about 50,000, preferably from 50,000 to 2,000,000.
• the chlorinated olefin polymer employed in the present invention suitably has from 15 to 45 weight percent, preferably from 30 to 40 weight percent, chemically combined chlorine.
• the chlorinated olefin polymer has a
• chlorinated olefin polymers are those taught in U.S. Patent Nos. 3,454,544; 3,819,554; and 4,767,823.
• the curing agent can be any peroxide- or thiadiazole-containing curing agent.
• typical thiadiazole curing agents include, for example, those disclosed in U.S. Patent Nos. 4,128,510 and
• thiadiazole curing agents include 2,5-dimercapto-1,3,4-thiadiazole and derivatives thereof.
• peroxide curing agents include, for example, n-butyl 4,4-bis(t-butylperoxy)- valerate, ⁇ , ⁇ '-bis(t-butylperoxy)diisopropyl benzene, and dicumyl peroxide. Mixtures of peroxide curing agents can be employed.
• the curing agent is employed in an amount sufficient to cure the chlorinated olefin polymer-containing formulation to the extent desired. Preferably, from 2 to 20 parts by weight, more
• peroxide curing agent preferably from 5 to 8 parts by weight, of peroxide curing agent are employed per 100 weight parts of chlorinated olefin polymer. From 0.5 to 10 parts by weight of thiadiazole curing agents are employed per 100 weight parts of chlorinated polyethylene.
• the polyacid is employed in an amount
• metal compounds typically are present in the form of metal compounds.
• metal compounds Preferably, from 0.1 to 10 parts by weight, more
• polyacid preferably from 1 to 7 parts by weight of polyacid are employed per 100 weight parts of chlorinated olefin polymer.
• the polyacid can be in the free acid form or in the salt form.
• the salt preferably is employed and is a salt of an alkali metal or an alkaline earth metal. Of these, sodium and calcium salts are preferred, with sodium salts being more preferred.
• the polyacid employed in this invention preferably has the general structural formula:
• A, D, E, G, J, and L are independently selected from hydrogen
• X and Y are independently selected from hydrogen, hydroxyl, carboxyl, phosphonic, salts of the acid radicals and hydrocarbon radicals having from 1 to 12 carbon atoms;
• X' and Y' are independently selected from hydrogen, methyl and ethyl radicals;
• n is from 1 to
• M is independently selected from hydrogen, alkali metal, ammonium radicals and an amine radical
• R is a hydrocarbon residue which can be a linear, branched, or cyclic radical, including a fused ring structure, a heterocyclic or substituted heterocyclic radical.
• the polyacids of the above formula are aminopolyacids and more preferably are aminopoly- carboxylic acids, of which the alkylene amino polyacetic acids and the salts thereof are more highly preferred.
• alkylene polyamine polyacetic acids having from 1 to 3 alkylene units including, for example, ethylenediaminetetraacetic acid and diethylene- triaminepentaacetic acid and the di- and tetrasodium salts of ethylenediaminetetraacetic acid, with the tetrasodium salt of ethylenediaminetetraacetic acid being most preferred.
• amino polyphosphonic acids are also preferred and are useful in the present invention and have the above general structural formula.
• Typical amino polyphosphonic acids or salts thereof include aminotris(methylene phosphonic acid), ethylenediamine- tetra(methylene phosphonic acid), diethylenetriamine- penta.methylene phosphonic acid), the pentasodium salt of amino tris(methylene phosphonic acid), the hexapotassium salt of ethylenediaminetetra(methylene
• alkylated polyacids such as hydroxyethyldiphosphonic acid and its tetrasodium salt, hexamethylenediaminetetra(methylene phosphonic acid), hexamethylenediaminetetraacetic acid, trisodium salt of N-[hydroxyethyl] ethylenediaminetetraacetic acid, their salts, and the like.
• polyacids can be employed as a solid or in a solution.
• the polyacids and amino polyacids can be added directly to the compound mixing apparatus, e.g. a Banbury mixer.
• the polyacids and amino polyacids are employed as an aqueous solution having from 40 to 50 weight percent polyacids and amino polyacids.
• the polyacids and amino polyacids preferably are added to the chlorinated olefin polymer and are adsorbed. The resulting wet chlorinated olefin polymer is then dried and milled. The resulting modified chlorinated olefin polymer can be directly added to the compound mixing apparatus.
• compositions of the present invention are useful in the preparation of wire and cable jacketing, automotive hose, molded goods, and extruded products.
• it is common to employ other ingredients such as pigments, stabilizers, lubricants, fillers, plasticizers, process aids, acid acceptors, antioxidants and the like, as is well known to those skilled in the art.
• An elastomer composition is prepared using the materials listed in Table I.
• the listed ingredients are added to a Banbury mixer in the following order: dry ingredients, wet ingredients, and chlorinated
• the ingredients are mixed until the temperature of the mixture reaches 220°F (104.4°C).
• the fused compound is then transferred to a two-roll mill.
• the mixed compound is rolled several times, and is then formed into a sheet, having a thickness of from 70 to 100 mils (1.75 to 2.5mm).
• a 40% aqueous solution of the polyacid or aminopolyacid is added to the chlorinated polyethylene in a 1:1 weight ratio, to produce a concentration of about 29% polyacid or amino polyacid on chlorinated polyethylene.
• the mixture is allowed to dry and is then milled.
• the milled mixture of chlorinated polyethylene and polyacid or aminopolyacid is added to the Banbury mixer as the chlorinated polyethylene.
• the resulting sheets are cut into 15 cm x 15 cm sample plaques and cured in a hydraulic press at 375°F (190.6°C) for ten minutes under 100 tons force, i.e. a pressure of 889 psi (6129 kilopascals). After curing, samples are allowed to stand at room temperature overnight.
• ECH0TM-A 2,5-di-mercaptothiadiazole benzoic acid (100%); a trademark of Hercules Incorporated
• VANAXTM 808, N-phenyltripropylpyridine a trademark of R. T. Vanderbilt Co. Ltd.
• VULCUPTM 40KE ⁇ , ⁇ '-bis(t-butylperoxy)diisopropyl- benzene on clay; a trademark of Herculses Inc.
• Comparative Experiment 1 produced ODR curves and tensile properties that showed an incomplete degree of compound cure. Maximum torque was 9.3 lb-in. (1.05 N.m), 200% modulus was 691 psi (4761 kPa), tensile was 1267 psi (8730 kPa) as opposed to being 24 to 32 lb-in. (2.7 to 3.6 N.m), 845 to 860 psi (5822 to 5925 kPa), and 1400 to 1435 psi (9646 to 9887 kPa) for each property, respectively, for Examples 1-3. Comparative Example 1, heat aged for 70 hours at 275°F (133°C) lost 73%
• Comparative Example 1 This indicates that Na 4 EDTA enables CPE compounds to achieve similar or better than expected results, even if the compound is contaminated with zinc compounds. Results indicate that a minimum of 5 parts Na 4 EDTA is required to prevent 1.0 part zinc stearate from interfering with the sulfur donor cure mechanism in this chlorinated polyethylene compound formulation.
• Comparative Experiment 2 did not show any significant difference in rheological or original physical properties as compared to Preparation 2. Air oven aged samples of Comparative Experiment 2 for 70 hours at 302°F (150°C) generated a loss in tensile of 31%, and a loss in elongation of 81%. Examples 4 to 6 produced a 2 to 8% tensile loss and a 30 to 37%
• Examples 5 and 6 produced results similar or better than Preparation 2. Results showed that a minimum of 5 parts of Na 4 EDTA was required to prevent chlorinated polyethylene heat degradation induced by one part of zinc stearate in this compound formulation.

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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)

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• 1990
  • 1990-12-04 JP JP50159791A patent/JPH04503828A/ja not_active Expired - Lifetime
  • 1990-12-04 CA CA 2045627 patent/CA2045627A1/en not_active Abandoned
  • 1990-12-04 WO PCT/US1990/007104 patent/WO1991008255A1/en not_active Application Discontinuation
  • 1990-12-04 EP EP19910901178 patent/EP0456810A4/en not_active Withdrawn

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