Classifications

• • 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
  • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
  • C08J7/12—Chemical modification
  • C08J7/16—Chemical modification with polymerisable compounds
  • C08J7/18—Chemical modification with polymerisable compounds using wave energy or particle radiation
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/10—Esters; Ether-esters
  • C08K5/101—Esters; Ether-esters of monocarboxylic acids
• • 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
  • C08J2321/00—Characterised by the use of unspecified rubbers

Definitions

• This invention relates to the vulcanization of rubber by exposing it to ionizing radiation, and more particularly it relates to the acceleration or enhancement of such vulcanization by having certain acrylate, diacrylate or dimethacrylate compounds present in the rubber during such exposure to ionizing radiation.
• rubber may be at least partially if not completely vulcanized when placed in a field of ionizing radiation. There are, however, limitations on this process. First, after a certain amount of exposure to such radiations, rubber has been observed to degrade.
• This invention shows that when small quantities of certain acryla-te, diacrylate or dimethacrylate compounds are mixed in with natural rubber or SBR (i.e., styrenebutadiene rubber, formerly known as GR-S or Buna-S) the amount of ionizing radiation necessary to effect cure is substantially reduced as shown in the working examples and tabulated results below.
• SBR styrenebutadiene rubber
• ionizing radiation is used here in its conventional sense as referring to radiation which when absorbed by matter produces ionization.
• Well known to the art as ionizing radiations are X-rays, gamma rays, high speed electrons, beta rays, and high speed protons, alpha particles and fast neutrons. Of these, X-rays, gamof at least about 8 electron volts.
• Table 10a on pages 105-115 of Electron 'Impact Phenomena and Properties of Gaseous Ions, by F. H. Field and I. L. Franklin (Academic Press, Inc., 1957).
• Energy sources for such high energy ionizing radiation may be electron accelerators of the Van de Graatf or linear types or cobalt sources or nuclear reactors, etc.
• the permissible irradiation dosage is from 4 to 40 watt hours per pound of material with a dosage of from 4 to 20 Watt hours per pound preferred. This permissible dosage is equivalent to 3.2)(10 to 32x10 rad.
• methacrylates are ineffective in achieving the desired results while both acrylates and dimethacrylates as well as diacrylates are effective.
• the desired compositions were mixed on a cold mill and test slabs of 6 /2 x 6 /2 x 0.1" were molded in a press for 5 minutes at 260 F.
• the slabs were then irradiated either in an X-ray machine or by exposure to a beam of 2 million volt electrons obtained from a Van de Graaif accelerator. To prevent undue heating of samples, intermittent exposures were used; the total dosage being controlled by the total time of exposure. Tests on the treated slabs were carried out by using conventional rubber testing equipment.
• modulus 2 300% modulus with dosages of 0, 4, 10, 20. Control values of modulus are 46, 138, 225, 645 psi. 3 Commercial material sold as Monomer MG-l by Union Carbide and Carbon 00.
• ma rays and high speed electrons are particularly suitable to this invention.
• the operative radiation may be described as high energy radiation, the individual particles or photons of which possess energies From these data it may readily be observed that significant results are obtained when .the following compounds are employed.
• the amount of additive used is in all cases at least 1 /2 parts, per 1100 parts of rubber.
• the amount used typically varies with the amount of active component in the compound.
• acrylate or methacrylate component per 100 parts of rubber.
• the compound contains only about 40% acrylate hence at least 4 parts are used.
• alkyl monomethacrylates are ineffective while dimethacrylates are effective.
• the preferred additives are:
• Alkyl acrylates/alkyl from C to C Diacrylates and dimethacrylates of polyethylene glycol, having a molecular weight of from about 170 to 1000. Diacrylates and dimethacrylates of ethylene, propylene and tetramethylene glycols.
• Durorneter 5 TABLE 4-Continued Smoked Sheet With Octyl Acrylwte and Daryl Meth- Stock N 9 10 11 12 SBB 1500 100 100 100 100 acrylate and Control Philblack O 55 50 55 60 Octyl acrylate 10 20 Octyl methaerylate Stock N o 22 23 24 25 26 Rubber SS 100 100 100 100 100 Philblack O 50 55 60 55 60 Torsional hysteresis at room Octyl acrylate 10 20 temperature Ogtyl methacrylnte 10 20 Tensile strength, lbs/in. Rizgiation dose, weight hrsJ Elongation, percent 200% modulus, lbs/in.
• Torsional hysteresis at room temperature Torsional hysteresis at 280 F.
• a method of vulcanizing a rubber composition com.- prising subjected said composition to a dosage of from 4 to 40 Watt hours of high energy ionizing radiation per pound of said composition, the said composition comprising 100 parts by weight of a rubber selected from the group consisting of Hevea rubber and SBR, and, as an accelerator, from 1.5 to parts of a material selected from the group consisting of alkyl acrylates, acrylic esters of saturated dihydric alcohols, methacrylic esters of saturated dihydric alcohols, acrylic esters of polydihydric alcohols, and 'methacrylic esters of polydihydric alcohols.
• a method of vulcanizing a rubber composition comprising subjecting said composition to a dosage of from 4 to 'Watt hours of high energy ionizing radiation per pound of said composition, the said composition comprising 100 parts by weight of a rubber selected from the group consisting of Hevea rubber and SBR, and, as an accelerator, *from 1.5 to 15 parts of a material selected from the group consisting of alkyl acrylates in which the alkyl group has from 4 to 12 carbon atoms, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, ethylene diacrylate, ethylene dimethacrylate, propylene diacrylate, propylene dimethacrylate, tetramethylene diacrylate and tetramethylene dimethacrylate.
• a vulcanized rubber composition comprising parts by weight of a rubber selected from the group consisting of Hevea rubber and SBR, and, as an accelerator, from 1.5 to 15 parts of a material selected from the group consisting of alkyl acrylates, acrylic esters of saturated dihydric alcohols, methacrylic esters of saturated dihydric alcohols, acrylic esters of polydihydric alcohols and methacrylic esters of polydihydric alcohols, said composition having been vulcanized by the method of claim 1.
• a vulcanized rubber composition comprising 100 parts by weight of a rubber selected from the group consisting of Hevea rubber and SBR, and, as an accelerator, from 1.5 to 15 parts of a material selected from the group consisting of alkyl acrylates in which the alkyl group has from 4to 12 carbon atoms, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, ethylene diacrylate, ethylene dimethacrylate, propylene diacrylate, propylene dimethacrylate, tetramethy-lene diacrylate, and tetramethylene dimethacrylate, said composition having been vulcanized by the method of claim 2.

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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)
• Toxicology (AREA)
• General Chemical & Material Sciences (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Graft Or Block Polymers (AREA)
• Polymerisation Methods In General (AREA)

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Cited By (11)

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Citations (8)

Family Cites Families (1)

• 0
  • NL NL124741D patent/NL124741C/xx active
  • NL NL247416D patent/NL247416A/xx unknown
  • LU LU38113D patent/LU38113A1/xx unknown
• 1959
  • 1959-01-16 US US787100A patent/US3084115A/en not_active Expired - Lifetime
  • 1959-11-27 GB GB40333/59A patent/GB881281A/en not_active Expired
  • 1959-12-18 DE DEU6754A patent/DE1208069B/de active Pending
  • 1959-12-23 FR FR814034A patent/FR1244671A/fr not_active Expired
  • 1959-12-28 BE BE586059A patent/BE586059A/fr unknown

Patent Citations (8)

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