Abstract: A process for producing squaric acid comprises reacting hexachlorocyclobutene, or its mixtures with hexachlorobutadiene, with 96-100% sulfuric acid, at 80.degree.-150.degree. C., and adding at least the stoichiometric amount of water required for the hydrolysis, while maintaining the acid concentration between 96% and 100% throughout the reaction.

Abstract: Quadratic acid bisamides and salts thereof having the formula I are effective stabilizers of synthetic resins, especially for imparting resistance to deterioration resulting from exposure to light ##STR1## wherein R.sub.1 is H, C.sub.1-12 alkyl or OH-substituted C.sub.2-12 alkyl; R.sub.2 is --(CH.sub.2).sub.m --O--.sub.n, wherein m is an integer of 2-6; n is 0 or 1;R.sub.3 is H, CH.sub.3, CH.sub.2 --CH.sub.2 --OH, CH.sub.2 --COOH or CH.sub.2 --CH.sub.2 --COOH;HX is an acid equivalent of an unsubstituted or substituted monobasic, dibasic or polybasic organic acid of not more than 20 carbon atoms, or of sulfuric or phosphoric acid; and0.ltoreq.p.ltoreq.2.

Abstract: Amino-group bearing, low molecular weight 1,3-butadiene polymers used as stabilizers for molded or unshaped plastics in amounts of 0.01 to 2.0 weight percent referred to the plastic, where the amino-group bearing component is derived from a substituted piperidine having the general formula: ##STR1## where R represents similar or different alkyl groups having 1 to 3 carbon atoms.

Abstract: A process for preparing a pentachloro-3-butenoic acid alkyl ester comprises reacting the corresponding 1-alkoxyheptachloro-3-butene with an aqueous solution of an alkali metal carbonate. In a preferred embodiment, the starting material 1-alkoxyheptachloro-3-butene is the solution obtained as the reaction product of the reaction of the corresponding 1-alkoxypentachloro-1,3-butadiene with chlorine.

Abstract: A process for preparing tetrachlorocyclobutenone from hexachlorocyclobutene comprises reacting (a) hexachlorocyclobutene withI. (b) anhydrous sulphuric acid and (c) sulphur trioxide; orII. (b) anhydrous sulphuric acid and (d) phosphorus pentoxideat a temperature of 30.degree.-140.degree. C.;the starting materials being present in the following molar ratios at the start of the reaction:for I,(a):(c)=0.67-10, and(b):(c)=0.1-10;and for II,(a):(d)=0.67-10 and(b):(d)=0.5-20.

Abstract: A process for preparing a 2,3,4,4-tetrachloro-3-butenoic acid ester comprises reacting tetrachlorocyclobutenone in the presence of hexachloro-1,3-butadiene with an alcohol at a temperature of 125.degree.-200.degree. C.

Abstract: Ethylene and at least one other 1-monoolefin monomer, alone or in admixture with a non-conjugated hydrocarbon diene monomer, are copolymerized in the presence of organic chlorine compound-activated Ziegler-Natta catalyst, wherein the organic chlorine compound is a hydrocarbon or a halohydrocarbon ester of up to 15 carbon atoms of 2,3,4,4-tetrachloro-3-butenoic acid.

Abstract: Pentachlorovinylacetyl chloride is prepared by chlorinating tetrachlorocyclobutenone with a chlorinating agent such as (a) Cl.sub.2, optionally in the presence of additives, e.g., phosphorous pentachloride, antimony pentachloride, or oxides, hydroxides or carbonates of metals such as alkali or alkaline earth metals; or (b) phosphorous pentachloride.

Abstract: Shaped or unshaped synthetic resins having about 0.01-5% by weight of stabilizers where the stabilizers are bisamides of quadratic acids having the general formulas I and/or II as follows: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4, are identical or different, and represent(A) hydrogen, unsubstituted or substituted alkyl or alkenyl residues of 1-22 carbon atoms, one or more of which can also be substituted by hetero atoms;(B) unsubstituted or substituted cycloalkyl or cycloalkylalkylene residues;(C) unsubstituted or substituted aryl and arylalkylene residues;(D) 3- to 8-membered, unsubstituted or substituted rings which contain one or more hetero atoms and which can optionally be connected to the nitrogen atoms of Formulae I and II by way of alkylene groups;(E) furthermore the groups --NR.sub.1 R.sub.2 and/or --NR.sub.3 R.sub.4 represent 3- to 8-membered, unsubstituted or substituted rings which optionally contain additional hetero atoms; and(F) respectively R.sub.1 and R.sub.3 or R.sub.2 and R.