This invention produces technical (meth)acrylic acid without being confronted with problems of fouling of systems to purify the crude reaction mixture of (meth)acrylic acid synthesis, due to the presence of glyoxal formed during synthesis. The invention is based on the addition or generation of quinoline derivative in a glyoxal-containing (meth)acrylic acid flow in a quinoline/glyoxal derivative molar ratio ranging from 0.1 to 5, during the purification steps, said quinoline compound with one of formulas (I) or (II): ##STR00001##
wherein, groups R.sub.1, R.sub.2, R.sub.3, and R.sub.4 independently denote a hydrogen atom or a C.sub.1-C.sub.6, or R.sub.1 et R.sub.2 C-alkyl group combine and together with the atoms to which they are attached, form a saturated or unsaturated ring or heterocycle, preferably a phenyl group, and/or R.sub.3 and R.sub.4 combine and with the atoms to which they are attached, form a saturated or unsaturated ring or heterocycle, preferably a phenyl group.

The present invention generally relates to processes for converting acrylate esters or a derivative thereof to difluoropropionic acid or a derivative thereof. This process is generally performed using fluorine gas in a hydrofluorocarbon solvent.

The present invention generally relates to processes for converting acrylate esters or a derivative thereof to difluoropropionic acid or a derivative thereof. This process is generally performed using fluorine gas in a hydrofluorocarbon solvent.

The present invention relates to a method for preparing 1,3-cyclohexanedicarboxylic acid capable of exhibiting excellent activity, of enhancing the reaction efficiency and economic efficiency by using a catalyst having improved durability under the reaction conditions of high temperature and strong acid, of achieving excellent conversion rates by allowing most of reactants to participate in the reaction, and of obtaining products having high purity while minimizing by-products within a shorter period of time. The method for preparing 1,3-cyclohexanedicarboxylic acid may include: reducing isophthalic acid in the presence of a metal catalyst fixed to a silica support and containing a palladium (Pd) compound and a copper (Cu) compound in a weight ratio of 1:0.1 to 0.5.

The present invention relates to a method for preparing 1,3-cyclohexanedicarboxylic acid capable of exhibiting excellent activity, of enhancing the reaction efficiency and economic efficiency by using a catalyst having improved durability under the reaction conditions of high temperature and strong acid, of achieving excellent conversion rates by allowing most of reactants to participate in the reaction, and of obtaining products having high purity while minimizing by-products within a shorter period of time. The method for preparing 1,3-cyclohexanedicarboxylic acid may include: reducing isophthalic acid in the presence of a metal catalyst fixed to a silica support and containing a palladium (Pd) compound and a copper (Cu) compound in a weight ratio of 1:0.1 to 0.5.

The present invention generally relates to processes for converting acrylate esters or a derivative thereof to difluoropropionic acid or a derivative thereof. This process is generally performed using fluorine gas in a hydrofluorocarbon solvent.

The present invention generally relates to processes for converting acrylate esters or a derivative thereof to difluoropropionic acid or a derivative thereof. This process is generally performed using fluorine gas in a hydrofluorocarbon solvent.

Polymerization inhibitor compositions are provided. The polymerization inhibitor compositions may include at least one hydroxylamine of a nitroxide and at least one phenylenediamine. Methods of inhibiting the unwanted polymerization of monomers are also provided. The methods include adding the presently disclosed polymerization inhibitor compositions to a fluid containing the monomers. The monomers may be ethylenically unsaturated monomers, such as acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrolein, methacrolein, acrylate, methacrylate, acrylamide, methacrylamide, vinyl acetate, butadiene, ethylene, propylene, and styrene.

Polymerization inhibitor compositions are provided. The polymerization inhibitor compositions may include at least one hydroxylamine of a nitroxide and at least one phenylenediamine. Methods of inhibiting the unwanted polymerization of monomers are also provided. The methods include adding the presently disclosed polymerization inhibitor compositions to a fluid containing the monomers. The monomers may be ethylenically unsaturated monomers, such as acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrolein, methacrolein, acrylate, methacrylate, acrylamide, methacrylamide, vinyl acetate, butadiene, ethylene, propylene, and styrene.

Polymerization inhibitor compositions are provided. The polymerization inhibitor compositions may include at least one hydroxylamine of a nitroxide and at least one phenylenediamine. Methods of inhibiting the unwanted polymerization of monomers are also provided. The methods include adding the presently disclosed polymerization inhibitor compositions to a fluid containing the monomers. The monomers may be ethylenically unsaturated monomers, such as acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, acrolein, methacrolein, acrylate, methacrylate, acrylamide, methacrylamide, vinyl acetate, butadiene, ethylene, propylene, and styrene.