Patents Assigned to The Dow Chemical Co.
  • Patent number: 4331779
    Abstract: The dimensional stability of relatively unstable substantially closed-cell low density foams of non-ionic ethylenic polymers (e.g., polyethylene, ethylene/vinyl acetate copolymers, etc.) can be notably improved by the incorporation therein (during the preparation thereof) of from about 5 to about 95 weight percent (based on total polymer weight) of a copolymer of ethylene with from about 3 to about 45 weight percent of a monoethylenically unsaturated carboxylic acid.
    Type: Grant
    Filed: July 7, 1980
    Date of Patent: May 25, 1982
    Assignee: The Dow Chemical Co.
    Inventor: Chung P. Park
  • Patent number: 4330525
    Abstract: High density, dead burned refractory magnesia (MgO) is produced by sintering compacts formed by simultaneously thermally dehydrating and mechanically working an aqueous slurry of magnesium hydroxide.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: May 18, 1982
    Assignee: The Dow Chemical Co.
    Inventors: Jack B. Reynolds, Charles R. Amos
  • Patent number: 4323665
    Abstract: .alpha.-Olfins, particularly higher olefins, are polymerized in the presence of a catalyst prepared by reacting (A) tetravalent tianium compounds such as titanium tetraalkoxide, (B) an organoaluminum compound, (C) an organomagnesium component such as a hydrocarbon soluble complex of dialkyl magnesium and an organoaluminum compound such as triethyl aluminum and, (D) as a halide source, a tetravalent tin compound such as tin tetrachloride. Polymers prepared by this process provide higher efficiencies than polymers prepared from a process utilizing catalysts employing HCl as the halide source.
    Type: Grant
    Filed: April 14, 1980
    Date of Patent: April 6, 1982
    Assignee: The Dow Chemical Co.
    Inventors: Kirby Lowery, Jr., Donald F. Birkelbach, Randall S. Shipley
  • Patent number: 4322356
    Abstract: Method of preparing chlorthalidone, an antihypertensive agent, and derivatives using a novel 3-(4'-chloro-3'-chlorosulfonylphenyl)phthalide intermediate and derivatives, and method of preparing said novel intermediate, are disclosed.
    Type: Grant
    Filed: March 24, 1980
    Date of Patent: March 30, 1982
    Assignee: The Dow Chemical Co.
    Inventors: Thomas J. Giacobbe, Halbert C. White
  • Patent number: 4322574
    Abstract: An improved corrosion resistant cable shielding tape adapted for use in electrical power and communications cables comprising a metal strip having a deformation resistant layer of polymeric resinous material tightly adhered to at least one side thereof, the deformation resistant layer having a deformation temperature of at least about 270.degree. F. The deformation resistant layer resists abrasion and penetration at the temperatures and pressures normally associated with cable manufacture, installation and/or service use. The deformation resistant layer must be tightly adhered to the metal strip to prevent delamination when exposed to a corrosive environment and to the mechanical forces exerted by metal corrosion products, thereby restricting the path of corrosive attack to the exposed metal edges of the shielding tape. Additional layers of polymeric resinous materials may be included in the multilayered structure of the cable shielding tape such as adhesive and/or heat seal layers.
    Type: Grant
    Filed: June 9, 1980
    Date of Patent: March 30, 1982
    Assignee: The Dow Chemical Co.
    Inventors: Kenneth E. Bow, Thomas H. Lyon
  • Patent number: 4319011
    Abstract: Compositions exhibiting high catalytic activity in the polymerization of .alpha.-olefins at temperatures above 140.degree. C. are provided by reacting a transition metal compound such as tetra(isopropoxy)titanium, an organomagnesium component such as a hydrocarbon soluble complex of dialkyl magnesium and an alkyl aluminum, e.g., di-n-butylmagnesium.x triethylaluminum and a hydrogen halide or an active hydrocarbyl halide such as t-butyl chloride. Polymerization processes employing this catalyst composition do not require conventional catalyst removal steps in order to provide polymers having suitable color and other physical characteristics.
    Type: Grant
    Filed: September 16, 1980
    Date of Patent: March 9, 1982
    Assignee: The Dow Chemical Co.
    Inventors: Kirby Lowery, Jr., George W. Knight, James A. May, Jr.
  • Patent number: 4315963
    Abstract: A process and apparatus for producing a ribbed pattern on extruded film by differential cooling of the film during its stretching process. The film is extruded through a tubular film die, stretching as it leaves the die. Cooling mechanisms rotate about the tube as it is being extruded to define a large plurality of narrow strips on the melt as it is being extruded. The film is fixed in space to maintain a close proximity to the cooling mechanisms in order to achieve sharply defined ribs. A cross-ribbed pattern can be obtained by counter-rotating the cooling mechanisms. Increased tear strength is imparted to the film without increasing the amount of resin necessary to make the film. Such tube can be formed into high strength film products such as trash bags and the like.
    Type: Grant
    Filed: July 18, 1980
    Date of Patent: February 16, 1982
    Assignee: The Dow Chemical Co.
    Inventor: Carl B. Havens
  • Patent number: 4312720
    Abstract: An electrolytic cell and a method of operating an electrolytic cell having an electrically conductive, foraminous separator support element which is maintained at a voltage potential sufficient to minimize the occurrence of substantial amounts of anodic reactions and cathodic reactions, thereby minimizing corrosion and bipolar effects at the support element.
    Type: Grant
    Filed: May 2, 1980
    Date of Patent: January 26, 1982
    Assignee: The Dow Chemical Co.
    Inventor: Joseph D. Lefevre
  • Patent number: 4311541
    Abstract: Composite foam panels are prepared from expanded thermoplastic particles of low density by generally encapsulating the particles in a phenolic foam matrix and providing a particulate expanded mineral substance such as perlite disposed generally adjacent the major surfaces of the panel.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: January 19, 1982
    Assignee: The Dow Chemical Co.
    Inventor: Duane A. Fultz
  • Patent number: 4310435
    Abstract: The method of chemically cleaning acid-soluble, sulfide-containing scale from a metal surface using an aqueous cleaning composition comprising an aqueous non-oxidizing acid having one or more aldehydes dissolved or dispersed therein is improved by generating the aldehyde in situ. An aqueous acid cleaning composition comprising hydrochloric or sulfuric acid and hexamethylene tetramine is a preferred composition.
    Type: Grant
    Filed: December 6, 1979
    Date of Patent: January 12, 1982
    Assignee: The Dow Chemical Co.
    Inventor: Wayne W. Frenier
  • Patent number: 4307155
    Abstract: A wood-polymer composite is prepared by impregnating a wood substrate with a liquid dicyclopentenyl acrylate or methacrylate monomer of the formula ##STR1## wherein R is hydrogen or methyl, R' and each R" are independently hydrogen, chloride or bromide, n is 0 or 1, and the dashed line is an optional chemical bond with the provisoes that when the dashed line is present, n is 0, and when the dashed line is absent, n is 1, and curing the resulting monomer-impregnated wood substrate by either heating same in the presence of a catalytic amount of a thermal initiator, such as a peroxide, or by exposing same to high-energy radiation, such as .gamma.-rays. The wood-polymer composite is relatively hard and shows good resistance to hydrocarbon attack.
    Type: Grant
    Filed: September 11, 1980
    Date of Patent: December 22, 1981
    Assignee: The Dow Chemical Co.
    Inventors: William E. Broxterman, Frederick L. Brown
  • Patent number: 4297475
    Abstract: Flame retardant intumescent polyamides comprising repeating structural units of the formulas ##STR1## wherein X is independently chloro or bromo, and n and n' are each independently a positive integer are disclosed.
    Type: Grant
    Filed: April 24, 1978
    Date of Patent: October 27, 1981
    Assignee: The Dow Chemical Co.
    Inventors: Linnea E. Nelson, Charles E. Reineke
  • Patent number: 4295919
    Abstract: An improved high speed cast process for fusing fasteners, with strips of film at their base, to separately extruded film or sheet stock for making containers with integral closure means. The process makes available multiple sets of male and female fastener elements, with variable spacing, in a single extrusion operation. The apparatus is configured so that adhesion between the fastener elements and the film or sheet occurs very closely to the die lips before significant cooling of the extrudate occurs. Containers with improved profiles are obtained because the base permits the profiles to remain relatively rigid during closing and opening.
    Type: Grant
    Filed: May 14, 1980
    Date of Patent: October 20, 1981
    Assignee: The Dow Chemical Co.
    Inventors: Thomas A. Sutrina, R. Douglas Behr
  • Patent number: 4296013
    Abstract: Discrete, crosslinked vinylidene chloride polymer microgels, having a latex particle size of less than 1 micron and a gel content of about 1 to 99 percent, such microgels being obtained by emulsion polymerizing (a) about 50 to about 95 parts by weight of vinylidene chloride, (b) about 5 to about 50 parts by weight of a copolymerizable ethylenically unsaturated comonomer, and (c) about 0.1 to about 10 parts by weight of a copolymerizable crosslinking polyfunctional comonomer. Such microgels have been found to have wide applicability as additives for synthetic foams and fibers, and for the preparation of improved coatings, films, and redispersible latexes.
    Type: Grant
    Filed: December 13, 1979
    Date of Patent: October 20, 1981
    Assignee: The Dow Chemical Co.
    Inventor: Dale S. Gibbs
  • Patent number: 4296019
    Abstract: A solvent blend capable of dissolving at a temperature of at least 60.degree. C. copolymers of ethylene and ethylenically unsaturated carboxylic acid. The solvent blend comprises from about 5 to about 35 percent by weight of an acyclic alcohol having from 2 to 12 carbon atoms, based upon the total weight of said solvent blend, about 3 percent to about 90 percent by weight of a monocyclic aromatic hydrocarbon, based upon the total weight of said solvent blend, and from about 5 to about 92 percent by weight of a halogenated C.sub.2 hydrocarbon, based on the total weight of said solvent blend. An exemplary solvent blend contains about 10 percent by weight of isopropanol, about 80 percent by weight of perchloroethylene, and about 10 percent by weight of toluene, based on the total weight of the solvent blend.
    Type: Grant
    Filed: November 29, 1979
    Date of Patent: October 20, 1981
    Assignee: The Dow Chemical Co.
    Inventors: Alfred R. Nelson, Kenneth E. Johnsen
  • Patent number: 4290775
    Abstract: Analytical method based on converting an acid or base species to water or absorbing the acid species whereby the species of interest is no longer responsive to a detector. Interfering salt(s) is simultaneously converted to a detectable acid or hydroxide derivative(s) in whole or in part. The species of interest is determined indirectly by subtracting the response of the salt derivative (which is proportional to the original salt) from a pre-derivatization response which is proportional to the salt plus base or salt plus acid.
    Type: Grant
    Filed: January 28, 1980
    Date of Patent: September 22, 1981
    Assignee: The Dow Chemical Co.
    Inventors: Timothy S. Stevens, Theodore E. Miller, Jr.
  • Patent number: 4290810
    Abstract: Coal and other particulate can be transported on a conveyor belt exposed to winter weather conditions with reduced slippage of the particulate on the belt surface by periodically treating the belt surface with from about 0.001 to about 0.005 gallons per square foot of belt surface (0.04-0.4 liters/sq. meter) of a composition containing a small amount of a dimethyl polysiloxane with the balance consisting substantially of water soluble components comprising (A) a water soluble polyhydroxy compound or monoalkyl ether thereof, and (B) a water soluble organic nonvolatile compound having at least one hydrophilic group, (A) being different from (B).
    Type: Grant
    Filed: May 4, 1979
    Date of Patent: September 22, 1981
    Assignee: The Dow Chemical Co.
    Inventor: Carl T. Montgomery
  • Patent number: 4288896
    Abstract: A thermoplastic lined plug valve is prepared using a plug having a nonlocking taper and a stem at the small end of the plug. The plug is seated initially by forcing the plug into the plug cavity, raising the temperature of the plug valve above the service temperature of the valve body lining until the valve body lining conforms to the valve plug. The valve is then cooled to a temperature below the service temperature of the body lining.
    Type: Grant
    Filed: December 17, 1979
    Date of Patent: September 15, 1981
    Assignee: The Dow Chemical Co.
    Inventors: Walter H. West, E. D. Prueter
  • Patent number: 4289814
    Abstract: The addition of a water-absorbent, finely divided powder to a phenolic resole resin provides a stabilized resin composition which cures in the presence of an acid catalyst at ambient temperatures to a relatively thick coating having a reduced number of defects, e.g., pinholes and blistering. For example, a resole resin composition containing a stabilizing amount of fumed silica can be blended with a mixture of benzene sulfonyl cloride and trichloroacetic acid, applied to a substrate and cured to form an essentially defect-free coating.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: September 15, 1981
    Assignee: The Dow Chemical Co.
    Inventors: C. Eugene Jinkins, Bobby Legler
  • Patent number: RE30796
    Abstract: .Iadd.Removing iron oxide scale or a mixture of iron oxide scale and hardness scale from a metal surface by contacting said scale with an aqueous solution containing at least one of an ammonium, amine, or hydroxyalkylamine salt of nitrilotriacetic acid, N-2, -hydroxyethylaminodiacetic acid, or alkylenepolyamine polycarboxylic acid at a pH of 8 to 11. .Iaddend.
    Type: Grant
    Filed: September 14, 1978
    Date of Patent: November 17, 1981
    Assignee: The Dow Chemical Co.
    Inventor: Chester A. Lesinski