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Showing papers on "Acrylic acid published in 1981"


Patent
George F. Vesley1
23 Jan 1981
TL;DR: In this paper, a photopolymerizable mixture of acrylic monomer such as 95 parts of an alkyl acrylate and 5 parts of acrylic acid and 0.01 to 2 parts by weight of a chromophore-substituted-halomethyl-s-triazine is presented.
Abstract: Photopolymerizable mixture of (a) acrylic monomer such as 95 parts of an alkyl acrylate and 5 parts of acrylic acid and (b) 0.01 to 2 parts by weight of a chromophore-substituted-halomethyl-s-triazine. The invention differs from the prior art in that the s-triazine has the formula (FORMULA) wherein R1, R2, R3 and R4 are independently hydrogen, alkyl or alkoxy groups, and 1 to 3 of R1, R2, R3 and R4 are hydrogen. This s-triazine can be made by a more simple and hence more economical process than can the s-triazine of the prior art, tends to provide desirably shortened reaction times and somewhat greater tolerance to oxygen, and avoids the yellowish color encountered in the prior art. The novel photopolymerizable mixture is primarily useful for making pressure-sensitive adhesive tapes.

219 citations


Journal ArticleDOI
Abstract: The Raman spectra of polyacrylamide and its covalently crosslinked gel (with N,N′-methylenebis-acrylamide as the crosslinking agent) in the region of 200–3600 cm−1 are discussed The vibrational band assignments for polyacrylamide are made on the basis of a comparison with the spectra of acrylamide, acrylic acid, polyacrylic acid, poly(vinyl alcohol), and other vinyl polymers The Raman spectra of polyacrylamide in the solid phase and in aqueous solution have similar spectral features The Raman spectra of gels with low crosslink content and of polyacrylamide in aqueous solution are comparable except that one new band, predominantly due to the residual monomer, appears in the gel phase An analysis based on polarized Raman, infrared and NMR spectra, model building, and group theoretical calculations suggests a structure dominated by isotactic species

74 citations


Patent
05 Nov 1981
TL;DR: In this paper, a precursor blend is formed from a mixture comprising from 13 to 52 weight percent of a crosslinked polymer of an ester of a C 1 -C 6 alkyl acrylic acid and a cycloalkyl alcohol, being in the form of fine particles at least 50% by weight of which have average diameters less than 150 microns.
Abstract: Compositions hardenable by exposure to heat or electromagnetic radiation are provided by blending from about 0% to about 50% by weight of an uncrosslinked polymer, from about 20% to about 66% of a polymerizable monomer capable of dissolving said polymer, from about 10% to about 70% of a crosslinked polymer in the form of discrete particles having average diameters of from 0.001 micron to about 500 microns and being swellable by said monomer, and from about 0.25% to about 27% of a crosslinking agent for said monomer. Such compositions exhibit superior chemical and physical characteristics when hardened and are suitable in a wide variety of applications as construction media. In accordance with a preferred form of the invention, a precursor blend is formed from a mixture comprising (A) from 13 to 52 weight percent of a crosslinked polymer of an ester of a C 1 -C 6 alkyl acrylic acid and a C 1 -C 20 alkyl or cycloalkyl alcohol, said crosslinked polymer being in the form of fine particles at least 50% by weight of which have average diameters less than 150 microns; (B) from 13 to 34 weight percent of an uncrosslinked polymerized ester of a C 1 -C 6 alkyl acrylic acid and a C 1 -C 20 alkyl or cycloalkyl alcohol having an average molecular weight of from 500,000 to 900,000 g/mole; (C) from 25 to 55% by weight of a polymerizable monomeric ester of a C 1 -C 6 alkyl acrylic acid and a C 1 -C 20 alkyl or cycloalkyl alcohol, which monomeric ester is capable of dissolving said uncrosslinked polymerized ester and of swelling, or interpenetrating, said crosslinked polymer particles; and (D) from 7% to 22% by weight of a crosslinking agent for said polymerizable monomeric ester. Such precursor blends, after being aged for a time sufficient to insure that the crosslinked polymer particles have become substantially fully swollen with or interpenetrated by the mixture of monomeric ester and crosslinking agent, is especially suitable in the production of prosthetic dental appliances, such as, for example, prosthetic teeth.

66 citations


Journal ArticleDOI
TL;DR: In this paper, a preirradiation grafting of acrylic acid onto poly(tetrafluoroethylene) film was studied, and the influence of the grafting conditions were analyzed kinetically.
Abstract: Preirradiation grafting of acrylic acid onto poly(tetrafluoroethylene) film was studied. The trapped radicals formed upon irradiation are able to induce graft polymerization under appropriate conditions. The influence of the grafting conditions were analyzed kinetically. The grafting reaction begins close to the film surface and proceeds into the center with progressive monomer diffusion through the grafted layer. The dependences of the grafting rate on preirradiation dose and monomer concentration were found to be 0.2 and 1.1 order, respectively. The overall activation energies for this grafting were calculated to be 15.2 and 4.8 kcal/mol below and above 35/sup 0/C, respectively. The relationship between the grafting rate and film and film thickness gave negative first-order dependence.

62 citations


Journal ArticleDOI
TL;DR: The disappearance of acrylate esters in blood in vitro could be due at least in part to binding with non-protein sulfhydryls in red blood cells rather than to hydrolysis.

56 citations


Patent
29 May 1981
TL;DR: In this article, the reverse-phase suspension polymerization of unsaturated carboxylic acid is carried out in the presence of a dispersing agent and a crosslinking agent such as ethylene glycol, then water is removed from the polymer slurry by azeotropic distillation with (C) an organic solvent, preferably hexane until the water content comes down to 10W43wt%.
Abstract: PURPOSE: After the reverse-phase suspension polymerization of unsaturated carboxylic acid, water is removed from the resultant polymer slurry by azeotripic distillation with an organic solvent to produce granular hydrogel of a specific water content scarcely showing tackiness. CONSTITUTION: The water-in-oil type reverse-phase polymerization of (A) an α,β- unsaturated carboxylic acid/or its alkali metal salt, preferably acrylic acid is carried out in the presence of (B) a dispersing agent and a crosslinking agent such as ethylene glycol, then water is removed from the polymer slurry by azeotropic distillation with (C) an organic solvent, preferably hexane until the water content comes down to 10W43wt%. Further, the remaining water is removed by drying to give the objective hydrogel. EFFECT: The stages of the production process are reduced to increase its productivity and permit the economical production of the hydrogel. COPYRIGHT: (C)1982,JPO&Japio

54 citations


Journal ArticleDOI
TL;DR: In this article, a series of poly(vinyl alcohol) membranes were modifed by radiation-induced graft copolymerization with acrylic acid and methacrylic acid monomers.
Abstract: A series of poly(vinyl alcohol) membranes were modifed by radiation-induced graft copolymerization with acrylic acid and methacrylic acid monomers. These grafted poly(vinyl alcohol) membranes were then tested for their separation and permeability characteristics in vacuum permeation and dialysis experiments. The permselectivity of the membranes toward methanol and water was studied on a vacuum permeation apparatus at 30, 40, and 50°C. The permeation process was found to be a temperature-activated process. The logarithm of the permeation rate varied linearly with the reciprocal of the absolute temperature. The permeability of the grafted membranes was found to increase with the degree of grafting, with no appreciable selectivity toward water in binary mixtures. The acrylic acid-grafted membranes generally showed greater improvement in permeability than the methacylic-grafted membranes. The permeability of the grafted membranes toward methanol, sodium chloride, urea, creatinine, and uric acid was studied in a dialyzer. In all cases, the grafted membranes showed an improved permeability toward these solutes over the commercial poly(vinyl alcohol) membranes. The dialysis results were then compared with those obtained for dialysis-grade cellophane membranes. For the case of sodium chloride, urea, and methanol, the permeability of the grafted membranes was comparable to that of cellophane. A comparison of commercial and grafted poly(vinyl alcohol) membranes in their permeability toward ionic solutes exhibited somewhat anomalous behavior in that the permeability of the commercial membranes was higher than that of the grafted membranes. This related to the ionic nature of the modified membrane. The permeability coefficients determined in the dialysis experiments were found to be directly related to the degree of hydration of the grafted membrane. This behavior was attributed to changes in the size and shape of voids within the membrane structure.

53 citations


Patent
14 Dec 1981
TL;DR: In this article, the flame protection agent is provided with a compound in a proportion by weight of 7.5 to 30% which contains at least one sulfo group or sulfonium ion.
Abstract: In order to improve the flame protection effect without substantially impairing the mechanical properties of the articles covered with the flame protection agent, the flame protection agent is provided with a compound in a proportion by weight of 7.5 to 30% which contains at least one sulfo group or sulfonium ion. This compound is preferably a water soluble ammonium salt. As binder there is used an aqueous solution or aqueous dispersion of an organic material, particularly of an acrylate or of a polymer or copolymer having a base of acrylic acid ester. It is particularly advantageous if substantially open-cell polyurethane foam having a base of polyether is impregnated with such a flame protection agent which contains an ammonium salt of an aminosulfonic acid in a proportion of about 12%. Polyurethane foams impregnated in this manner are particularly well suited for use in cushionings of articles or in premises for which class B1 fire protection is required.

53 citations


Patent
13 Oct 1981
TL;DR: Aqueous acrylic polymer emulsions as mentioned in this paper contain a core-shell polymer having a core formed from one or more monomers selected from styrene, vinyl acetate, vinyl toluene and acrylic or methacrylic acid esters of alcohols of 1 to 4 carbon atoms.
Abstract: Aqueous acrylic polymer emulsions containing as a first polymeric component a core-shell polymer having a core formed from one or more monomers selected from styrene, vinyl acetate, vinyl toluene and acrylic or methacrylic acid esters of alcohols of 1 to 4 carbon atoms and a shell formed of the above monomers in conjunction with one or more monomers selected from acrylic acid or methacrylic acid esters of alcohols of 1 to 8 carbon atoms and a minor amount of acrylic or methacrylic acid and as a second polymeric component a polymer composed of a major amount of one or more monomers selected from styrene, vinyl acetate, vinyl toluene and acrylic or methacrylic acid esters of alcohols of 1 to 4 carbon atoms and a minor portion of one or more acrylic acid esters of alcohols of 1 to 8 carbon atoms with acrylic and/or methacrylic acid.

44 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that the presence of 10% by weight of copolymerised acrylic acid increases the thermodynamic work of adhesion by a factor of about 1.5.
Abstract: The introduction of carboxylic acid groups into a poly(butyl acrylate) adhesive greatly increases its bond strength to a glass substrate, as may be seen in a changed force-rate relationship for separation by peeling. By selective carboxylation of the bulk only or the surface only of the adhesive, it is possible to discriminate between bond enhancement by an interfacial effect (presumed to involve interfacial hydrogen bonding) and that by a bulk effect (change in visco-elastic response resulting from carboxylation). The interfacial effect provides a somewhat lower contribution towards the improvement of bond strength than does the bulk effect. Energetic considerations show that the presence of 10% by weight of copolymerised acrylic acid increases the thermodynamic work of adhesion by a factor of about 1.5.

44 citations


Patent
04 Sep 1981
TL;DR: In this article, the authors describe a process for producing methacrylic acid esters modified polyesters, curable by irradiation, characterised in that a saturated polyester, preferably carrying primary hydroxy groups and optionally polyether radicals and having an average molecular weight of between 500 and 3000, is mixed at from 80 to 140 degrees C, in the presence of at least one polymerisation inhibitor volatile with water vapour, with from 30 to 90 mole-% (calculated on the hydroxy group of the polyester) with acrylic acid or a mixture of acrylic acid and
Abstract: 1. Process for producing (meth)acrylic acid esters modified polyesters, curable by irradiation, characterised in that a saturated polyester, preferably carrying primary hydroxy groups and optionally polyether radicals and having an average molecular weight of between 500 and 3000, is mixed at from 80 to 140 degrees C, in the presence of at least one polymerisation inhibitor volatile with water vapour, with from 30 to 90 mole-% (calculated on the hydroxy groups of the polyester) with acrylic acid or a mixture of acrylic acid and methacrylic acid and is reacted, in the presence of an esterification catalyst, to a ratio of at least 40%, preferably of from 50 to 70% (calculated on the acid used) subsequently the reaction water formed being distilled off, in the presence of an azeotropic esterification catalyst, with the aid of a hydrocarbon solvent with a boiling point of between 60 and 130 degrees C, and, subsequently to stripping the solvent, optionally by stripping the solvent by vacuum, or using a distillation column, the acrylic acid having remained free being reacted with a quantity of a mono- or diepoxy compound equivalent to the free acid, at from 80 to 120 degrees C, to an acid value of a maximum of 10 mg KOH/g, using triphenylphosphine as catalyst.



Patent
05 Nov 1981
TL;DR: In this article, a method and a composition for controlling the deposition of scale imparting precipitates on structural parts of a system exposed to an aqueous medium containing scale-bearing precipitates, under scale- imparting conditions, are disclosed.
Abstract: There is disclosed a method and a composition for controlling the deposition of scale imparting precipitates on structural parts of a system exposed to an aqueous medium containing scale imparting precipitates, under scale imparting conditions, are disclosed. Specifically. these precipitates are either calcium carbonate, calcium sulfate. calcium phosphate or mixtures thereof. The method and composition are also efficacious in dispersing inorganic and organic matter, which may exist within a cooling system, boiler system, or the like. The composition comprises an acrylic acid/lower alkyl hydroxylated acrylate copolymer (I) which is administered to the system in combination with an ester of an aliphatic sulphodicarboxylic acid (II). Preferred esters include the dioctylester of sodium sulphosuccinic acid, the diisobutylester of sodium sulphosuccinic acid. the dihexyles- ter of sodium sulphosuccinic acid. The method comprises administering an effective amount of the compounds (I and II) to the aqueous system to be treated.


Patent
Laurence G. Dammann1
05 Oct 1981
TL;DR: In this paper, a novel polyacrylate thickening agent which is composed of monomers comprising (meth)acrylic acid, (2) glyceryl allyl ether derivative, and optionally (3) one or more other polymerizable monomers.
Abstract: This invention provides a novel polyacrylate thickening agent which is composed of monomers comprising (1) (meth)acrylic acid, (2) glyceryl allyl ether derivative, and optionally (3) one or more other polymerizable monomers. In another embodiment, this invention provides a print paste containing the defined novel polyacrylate thickening agent.

Patent
05 Nov 1981
TL;DR: In this article, a precursor blend is formed from a mixture comprising from 13 to 52 weight percent of a crosslinked polymer of an ester of a C1 -C6 alkyl acrylic acid and a C 1 -C20 alkyyl or cycloalkyl alcohol, being in the form of fine particles at least 50% by weight of which have average diameters less than 150 microns.
Abstract: Compositions hardenable by exposure to heat or electromagnetic radiation are provided by blending from about 0% to about 50% by weight of an uncrosslinked polymer, from about 20% to about 66% of a polymerizable monomer capable of dissolving said polymer, from about 10% to about 70% of a crosslinked polymer in the form of discrete particles having average diameters of from 0.001 micron to about 500 microns and being swellable by said monomer, and from about 0.25% to about 27% of a crosslinking agent for said monomer. Such compositions exhibit superior chemical and physical characteristics when hardened and are suitable in a wide variety of applications as construction media. In accordance with a preferred form of the invention, a precursor blend is formed from a mixture comprising (A) from 13 to 52 weight percent of a crosslinked polymer of an ester of a C1 -C6 alkyl acrylic acid and a C1 -C20 alkyl or cycloalkyl alcohol, said crosslinked polymer being in the form of fine particles at least 50% by weight of which have average diameters less than 150 microns; (B) from 13 to 34 weight percent of an uncrosslinked polymerized ester of a C1 -C6 alkyl acrylic acid and a C1 -C20 alkyl or cycloalkyl alcohol having an average molecular weight of from 500,000 to 900,000 g/mole; (C) from 25 to 55% by weight of a polymerizable monomeric ester of a C1 -C6 alkyl acrylic acid and a C1 -C20 alkyl or cycloalkyl alcohol, which monomeric ester is capable of dissolving said uncrosslinked polymerized ester and of swelling, or interpenetrating, said crosslinked polymer particles; and (D) from 7% to 22% by weight of a crosslinking agent for said polymerizable monomeric ester. Such precursor blends, after being aged for a time sufficient to insure that the crosslinked polymer particles have become substantially fully swollen with or interpenetrated by the mixture of monomeric ester and crosslinking agent, is especially suitable in the production of prosthetic dental appliances, such as, for example, prosthetic teeth.

Journal ArticleDOI
R. A. Weiss1, P. K. Agarwal1
TL;DR: In this article, the properties of propylene-acrylic acid copolymer copolymers have been studied and their rheological behavior has been investigated. And the results are a consequence of intermolecular interactions between salt groups for the metal acrylate derivatives and hydrogen bonding for acid derivatives.
Abstract: Ionomers based on propylene-acrylic acid copolymer have been prepared and their rheological behavior studied. With different cations the melt viscosity at any shear rate increases as tributylamine salt < acid < zinc salt < sodium salt. Similarly, the activation energies for viscous flow follow the order polypropylene - tributylamine salt < acid - zinc salt < sodium salt. These results are a consequence of intermolecular interactions between salt groups for the metal acrylate derivatives and hydrogen bonding for the acid derivatives. Strong ionic interactions are absent in the tributylamine salt because of steric hindrance of the bulky amine substituents. The glass transition temperatures for these materials were equivalent. The elastic properties of these polymers follow a similar trend as does the viscosity.

Journal ArticleDOI
TL;DR: In this paper, the dimensional change by grafting and swelling, water uptake, electric conductivity, and mechanical properties of the grafted PTFE films were measured and were found to increase as the grafting proceeds.
Abstract: Some properties of the membranes obtained by the preirradiation grafting of acrylic acid onto poly(tetrafluoroethylene) (PTFE) film have been studied. The dimensional change by grafting and swelling, water uptake, electric conductivity, and mechanical properties of the grafted PTFE films were measured and were found to increase as the grafting proceeds. These properties were found to be dependent mainly on the degree of grafting regardless of grafting conditions except higher monomer concentration (80 wt %). The electric conductivity and mechanical properties of the membranes at 80 wt % monomer concentration is lower than those at a lower monomer concentration. The results suggest that the membranes obtained at 80-wt % acrylic acid solution have a somewhat heterogeneous distribution of electrolyte groups as compared with those prepared at a monomer concentration less than 60 wt %. X-ray microscopy of the grafted films revealed that the grafting begins at the part close to the film surface and proceeds into the center with progressive diffusion of monomer to give finally the homogeneous distribution of electrolyte groups. The membranes show good electrochemical and mechanical properties which make them acceptable for the practical uses as cation exchange membrane.



Patent
29 Oct 1981
TL;DR: In this article, metal compounds such as antimony oxide and magnesium oxide are used to enhance the notched Izod impact resistance of molded objects made from selected polyamide copolymer compositions.
Abstract: Certain metal compounds such as antimony oxide and magnesium oxide are used to enhance the notched Izod impact resistance of molded objects made from selected polyamide copolymer compositions comprised of polyepsiloncaprolactam (nylon-6) or polyhexamethyleneadipamide (nylon-66) and preferably ethylene/ethyl acrylate and ethylene/acrylic acid copolymers.


Patent
08 Apr 1981
TL;DR: In this article, a method for treating pelts or leather in the beamhouse, for tanning, or as an aftertreatment, which consisted of contacting said pelts and leather with an aqueous solution or dispersion of a copolymer comprising monomers of a nitrogenous ester of acrylic acid or of methacrylic acid, a further different ester, acrylic acid and methacric acid, and acrylic acid/methacoric acid, whereby portions of said copolymers are deposited in the grain layer without formation of a superficial film, was described.
Abstract: What is disclosed are a method for treating pelts or leather in the beamhouse, for tanning, or as an aftertreatment, which method comprises contacting said pelts or leather with an aqueous solution or dispersion of a copolymer comprising monomers of a nitrogenous ester of acrylic acid or of methacrylic acid, a further different ester of acrylic acid or of methacrylic acid, and acrylic acid or methacrylic acid, whereby portions of said copolymer are deposited in the grain layer without formation of a superficial film, and pelts and leather treated by this method.

Journal ArticleDOI
TL;DR: In this paper, the authors used doule resonance with coupled multiplets to measure the nuclear quadrupole resonance spectra of 17O at both the C�O and COH sites.

Patent
08 Oct 1981
TL;DR: A particulate graft polymer is a core formed by a crosslinked homopolymer of a conjugated diene or a copolymer thereof with up to 10% by weight of styrene or acrylonitrile.
Abstract: A particulate graft polymer comprising (a) a core formed by a crosslinked homopolymer of a conjugated diene or a copolymer thereof with up to 10% by weight of styrene or acrylonitrile; (b) a first shell formed by a crosslinked homopolymer of an acrylic acid alkyl ester or a copolymer thereof with up to 30% by weight of vinyl monomers; (c) a second shell formed by a polymer of resin-forming monomers, a process for manufacturing these graft polymers by means of a multi-stage emulsion polymerization, and their application as molding compositions, optionally together with rigid thermoplastic resins.

Patent
25 Mar 1981
TL;DR: In this article, a water-soluble radical polymerization initiator is added to an aqueous solution of a water soluble ethylenially unsaturated monomer (e.g., (meth)acrylic acid) containing about 0.05W10wt% above-mentioned protective colloid.
Abstract: PURPOSE: To produce the titled polymer having a large particle size (≥ about 100μ), a high water absorption and a high water absorption rate, by subjecting a water-soluble ethylenically unsaturated mnomer containing a small amount of a crosslinking agent to W/O suspension polymerization by use of a specified protective colloid. CONSTITUTION: As a protective colloid is used an oil-soluble cellulose ester (ether) which is insoluble or slightly soluble at normal temperature and soluble at a polymerization temperature (≥ about 40°C) in a dispersing medium (e.g., (halogenate) aromatic hydrocarbon), (e.g., cellulose/acetate butyrate, ethyl- cellulose). Namely, a water-soluble radical polymerization initiator is added to an aqueous solution of a water-soluble ethylenially unsaturated monomer (e.g., (meth)acrylic acid) containing about 0.01W5wt% crosslinking agent (e.g., N,N'- methylenebis(meth)acrylamide). The resulting solution is suspension-polymerized by adding dropwise, under agitation, the solution to a hydrophobic dispersing medium (e.g., toluene, hexane) containing about 0.05W10wt% above-mentioned protective colloid. COPYRIGHT: (C)1982,JPO&Japio

Patent
22 Jul 1981
TL;DR: In this article, the authors present a resin composition which is usable for an exterior article without being coated on its surface when molded into the article and is excellent in the color tone and has good impact resistance and weatherability.
Abstract: Disclosed is a resin composition which is usable for an exterior article without being coated on its surface when molded into the article and is excellent in the color tone and has good impact resistance and weatherability, said composition comprising (1) 10 to 70% by weight of a high-rubber-content graft polymer obtained by polymerizing 50 to 10% by weight of a monomer mixture (C) comprising 10 to 90% by weight of at least one aromatic vinyl monomer and 90 to 10% by weight of at least one ethylenically unsaturated monomer represented by the following general formula: wherein R stands for a hydrogen atom or methyl group and X stands for a group -CN or -COOR, in which R1 stands for an alkyl group having 1 to 8 carbon atoms. in the presence of a latex of a multi-layer crosslinked acryiic rubber particles containing 5 to 30% by weight of a rigid crosslinked resin (A) having a core particle size of 0.15 to 0,40 µ in the interior of the rubber particles"and 45 to 85% by weight of a crosslinked acrylic acid ester polymer (B) comprising an acrylic acid ester as the main component in the outer layer of the rubber particles, so that the total amount of the components (A), (B) and (C) is 100% by weight, (II) 90 to 30% by weight of a thermoplastic resin obtained by polymerizing at least one alkyl acrylate or methacrylate represented by the following general formula: wherein R stands for a hydrogen atom or methyl group, and R, stands for an alkyl group having 1 to 8 carbon atoms, in an amount of at least 90% by weight, and (III) 0 to 50% by weight of a diene type rubber-containing thermoplastic resin, the sum of the amounts of the component (i), (II) and (III) being 100% by weight.

Patent
21 Jul 1981
TL;DR: In this paper, an aqueous solution of crude acrylic acid obtained by the vapor phase catalytic oxidation of propylene and/or acrolein is introduced into a dehydration column E through a line 12, and distilled together with an azeotropic agent introduced to the column through the line 16.
Abstract: PURPOSE:To recover acrylic acid free of water and by-products, from crude acrylic acid aqueous solution obtained by the vapor phase catalytic oxidation of propylene, in high recovery, preventing polymerization of acrylic acid, by using a dehydration column and an acetic acid separation column, and distillating in the presence of a specific azeotropic agent. CONSTITUTION:An aqueous solution of crude acrylic acid obtained by the vapor phase catalytic oxidation of propylene and/or acrolein is introduced into a dehydration column E through a line 12, and distilled together with an azeotropic agent introduced to the column through the line 16. The azeotropic agent is a compound which forms azeotropic mixtures with both water and acetic acid, is hardly soluble in water, and does not form an azeotropic mixture with acrylic acid. Whole water and formic acid and a part of acetic acid in the aqueous solution is distilled out from the top of the column E, and acrylic acid containing residual acetic acid is extracted from the bottom of the column, introduced into an acetic acid separation column F through a line 14, and distilled together with the above azeotropic agent to distil off the whole acetic acid and a small amount of acrylic acid through the top of the column F. A part of the acrylic acid is recycled to the column F through the line 18, and the remainder is returned to the dehydration column E through the line 16. The purified acrylic acid is recovered from the bottom of the column F.

Patent
02 Jan 1981
TL;DR: In the method of recovering oil from oil sand as mentioned in this paper, the oil sand is tumbled in an aqueous alkaline solution to form a floating mass in which the oil is dispersed and the oil then recovered from the mass.
Abstract: In the method of recovering oil from oil sand wherein the oil sand is tumbled in an aqueous alkaline solution to form a floating mass in which the oil is dispersed and the oil then recovered from the mass, the step of including in the aqueous alkaline solution 0.3 to 100 parts per million of a water-soluble member of the group consisting of anionic polyelectrolytes having a low molecular weight, acrylic acid, mannuronic acid and the sodium salts thereof.