Abstract: Methods and compositions are provided for inhibiting the polymerization of acrylic acid monomers during elevated temperature processing thereof or during storage or shipment of acrylic acid product. The compositions comprise a combination of a Mn source compound and a phenylenediamine compound having at least 1 N-H bond. The methods comprise adding from about 1-10,000 ppm of the combination to the particular acrylic acid containing medium for which such anti-polymerization protection is desired, per million parts of the acrylic acid medium.

Abstract: The invention provides a method of producing alkylene glycol monosorbates which comprises reacting sorbic acid and an alkylene oxide having 2 to 4 carbon atoms in a certain system containing a solvent inactive to the alkylene glycol monosorbates, one or more iron catalysts and one or more compounds consisting of phenothiazines and alkylphenols, washing the obtained synthesized liquid with an aqueous (bi)carbonate solution, and then purifying the washed liquid by distillation, and a method of reserving the alkylene glycol monosorbates.

Abstract: Polyester polyols containing the following recurring unit derived from .beta.-methyl-.delta.-valerolactone(OCH.sub.2 CH.sub.2 CH(CH.sub.3)CH.sub.2 CO)used to be low in stability. It has been discovered that the stability of the polyester polyols of this type can be improved by reducing the acid value to down 0.25 or lower, and that this can be effected by heat treatment under reduced pressure to remove low-boiling compounds and/or by addition of an organic carbodiimide.

Abstract: A composition and method of use for inhibiting the polymerization of acrylate esters during elevated temperature processing and during storage and handling thereafter.It comprises the combination of a Mannich reaction product, which is prepared from a substituted phenol, an aldehyde and ethylenediamine, and either phenylenediamine or derivatives thereof and/or phenothiazine or derivatives thereof.

Abstract: The ethanolamine salt of N-nitrosophenylhydroxylamine ("NPHA") is effective as a polymerization inhibitor for ethylenically unsaturated monomers. The ethanolamine salt can be prepared by reacting ethanolamine with the ammonium salt of NPHA. Advantageously, the ethanolamine salt is soluble in high concentrations in water and a variety of polar organic solvents.

Abstract: This invention relates to compositions and methods of inhibiting acrylate monomer polymerization at elevated temperatures comprising adding to the acrylate monomer an effective amount for the purpose of (a) a hydroxylamine having the formula ##STR1## wherein R and R' are the same or different and are hydrogen, alkyl, aryl, alkaryl or aralkyl groups, and (b) a para-phenylenediamine or derivative thereof having at least one N-H group. Preferably the phenylenediamine is a para-phenylenediamine having the formula ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and are hydrogen, alkyl, aryl, alkaryl, or aralkyl groups with the proviso that at least one of R.sup.1, R.sup.2, R.sup.3 or R.sup.4 is hydrogen.

Abstract: The ethanolamine salt of N-nitrosophenylhydroxylamine ("NPHA") is effective as a polymerization inhibitor for ethylenically unsaturated monomers. The ethanolamine salt can be prepared by reacting ethanolamine with the ammonium salt of NPHA. Advantageously, the ethanolamine salt is soluble in high concentrations in water and a variety of polar organic solvents.

Abstract: Certain substituted diaryl amines are used to inhibit the polymerization of ethylenically unsaturated monomers; for example, unsaturated carboxylic acids and derivatives thereof.

Abstract: Disclosed is a process for inhibiting polymerization of polymerizable ethylenically unsaturated monomers such as hydrocarbons, acids and esters, wherein manganese nitrite, i.e. Mn(NO.sub.2).sub.2, is employed as an inhibitor. A composition including a polymerizable ethylenically unsaturated monomer and Mn(NO.sub.2).sub.2 is also disclosed. In two preferred embodiments, acrylic acid and styrene, respectively, are the monomers.

Abstract: Disclosed is a process for inhibiting polymerization of polymerizable ethylenically unsaturated monomers such as hydrocarbons, acids and esters, wherein a cobalt (III), nickel (II) or manganese (II) complex of N-nitrosophenylhydroxylamine is employed. A composition including a polymerizable ethylenically unsaturated monomer and the complex is also disclosed. In a preferred embodiment, polymerization of an acrylic acid or an acrylate ester is inhibited.

Abstract: Hydrazine is utilized for preventing side reactions during the preparation and storage of polyisocyanates partially blocked with hydroxy amines which are utilized for the introduction of basic functional groups into organic coating compositions which are deposited cathodically in an electrodeposition process. The inhibiting compound is used in the form of hydrazine hydrate at a level of from about 50 to 5000 ppm calculated on the amine used in the reaction.

Abstract: New and improved compositions are described of ethylenically unsaturated organic compounds capable of addition polymerization stabilized from unintentional or premature polymerization in the liquid phase by the addition of the combination cerium compounds which are soluble in the ethylenically unsaturated organic compounds and phenolic type inhibitors.

Abstract: The present invention provides an improvement in methods for preparing and processing readily polymerizable acrylate monomers. The improvement comprises employing phenyl-para-benzoquinone, 2,5-di-phenyl-para-benzoquinone, and mixtures thereof as process inhibitors. The process inhibitors are present in a concentration of about 50 to 3000 ppm, preferably about 250 to 2000 ppm, and most preferably about 500 ppm.

Abstract: Shelf stability of hydroxyl terminated liquid polymers is vastly improved by mixing a strong inorganic or organic acid, therewith in order to adjust acid number thereof up to about 12. Amount of the acid used is less than 1% by weight of the liquid polymer.

Abstract: In a process for producing a 2-hydroxyalkyl acrylate or methacrylate which comprises esterifying acrylic or methacrylic acid with an alkylene oxide having 2 to 4 carbon atoms in the presence of an esterification catalyst and distilling the resulting reaction mixture in a distillation column, the improvement wherein the vapor of the ester monomer from the distillation column, while being maintained in the superheated state, is introduced into a condenser of the gas-liquid direct contact type whose inner wall corresponding to its gas inlet portion is kept at a temperature below the boiling point of the ester at the operating pressure, to contact it directly with a concurrently flowing spray liquid of the ester-precooled to a temperature below the boiling point of the ester at the operating pressure, whereby said vapor is condensed to a liquid at said temperature below the boiling point of the ester at the operating pressure.

Abstract: Inhibition of the formation of color bodies and color-forming materials and other contaminants and/or decolorization of discolored sulfur-containing organic compounds containing divalent sulfur by addition of a small amount of oxalic acid.

Abstract: A mixture of phenothiazine and para-nitrosophenol is a particularly effective stabilizer against premature polymerization of monomeric esters of acrylic acid with alkanols of 1 to 8 carbon atoms.

Abstract: The present invention relates to a method of purifying readily polymerizable high boiling vinyl monomers, in particular the acrylates and methacrylates of alkylene oxides and their ether and ester derivatives to obtain pure water white esters. The process involves flash evaporation of the preheated esters followed by condensation in the presence of polymerization inhibitors under specific conditions. The purified esters thus produced find use either as such or in the form of their copolymers in coatings, enamel paints, weather resistant finishes, adhesive compositions, as plasticizers, as lubricants for cellulose films and fibers, in magnetic tape recording media and as oil additives.

Abstract: A method is disclosed for inhibiting the polymerization of acrylic and methacrylic acids at ambient or above ambient temperature, such as during preparation, purification or storage of the acids under substantially anaerobic conditions, by adding thereto a polymerization inhibiting amount of a compound having the formula:R--NOwhere R is alkyl or aryl, and if R is aryl, a hydroxyl group para to the NO group enhances inhibition.

Abstract: The prior art discloses a number of polymerization inhibitors for acrylic acid, acrylates and derivatives thereof, but such polymerization inhibitors have low vapor pressures. Consequently, when acrylic acid is vaporized, it tends to polymerize on cooling surfaces causing undesirable deposits on storage vessels and the like. However, when a polymerization inhibiting amount of 2,4-pentanedione is added to the monomer, the polymerization of acrylic acid on cooling surfaces is inhibited.

Abstract: Stabilized acrylic acid esters of polyhydric alcohols which contain as stabilizers polymerisation inhibitors including small amounts of compounds of the styrene type show a non-reduced polymerisation reactivity.