摘要:
The invention relates to a process for the production of pure, substantially neutral, low-volatility organic compounds containing reactive olefinic double bonds from starting materials which contain these components together with small quantities of acidic reaction constituents and/or corresponding auxiliaries in the liquid phase by neutralization and separation of the salts formed. The process according to the invention is characterized in that, to obtain pure products which combine low residual acid values with low color standard numbers, even without distillation, the neutralization is carried out as dry neutralization using solid, finely powdered oxides, carbonates and/or hydroxides of the alkali and/or alkaline earth metals, if desired together with other insoluble basic metal oxide compounds, and the organic liquid phase is subsequently separated from the finely powdered solid phase. The oxides and/or hydroxides of calcium and/or magnesium are preferably used for neutralization.
摘要:
Described is the use of physiologically compatible tocopherols and especially of vitamin E as an inhibitor against premature polymerization initiation in reactive systems capable of undergoing a free radical-initiated polymerization, which systems before and/or after the polymerization thereof are placed in tissue contact with the living human or animal body and, more specifically, are implanted into the living organism thereby. The reactive systems and the polymers formed therefrom may be degradation resistant. However, a special embodiment relates to compositions or molded bodies which are decomposed by the living organism, and especially so under time-controlled conditions. The invention further relates to surgical binder systems which are suitable for adhesion bonding endogenous body tissue and which have been based on an adhesive component capable of being activated by free radicals, said adhesive component being present in admixture with a free radical inhibitor and being characterized in that the inhibitor or at least the predominant portion of the inhibitor is vitamin E. It is preferred that the described compositions are free from physiologically unacceptable solvents or residual amounts of solvents left from the preparation process.
摘要:
A process for the production of (meth)acrylic acid esters of polyhydric alcohols by reaction of the reactants in the presence of acidic esterification catalysts with addition of polymerization inhibitors to the reaction mixture and purging of the reactor interior with an oxygen-containing gas stream. The process is characterized in that that part of the reactor interior filled with gas phase is charged with finely divided liquid droplets containing polymerization inhibitor.
摘要:
The invention relates to a process for the production of (meth)acrylic acid esters of polyhydric alcohols by reaction of the reactants with acrylic acid and/or methacrylic acid in the presence of acidic esterification catalysts with addition of sterically hindered phenolic compounds as polymerization inhibitors. The process is characterized in that tocopherols are used as the sterically hindered phenolic compounds and .alpha.-tocopherol is preferably at least partly used. The process is preferably carried out using reaction mixtures which are liquid at room temperature and which are at least substantially free from solvents and/or azeotropic entraining agents; more particularly, the water of condensation formed is removed from the gas phase of the reaction zone.
摘要:
The invention relates to a process for the production of (meth)acrylic acid esters of polyhydric alcohols by reaction of the reactants in the presence of acidic esterification catalysts with addition of .alpha.-substituted phenolic compounds, more particularly di-tert.-butyl hydroquinone, as polymerization inhibitors. The new process is characterized in that the reaction mixtures used are liquid at room temperature and are at least substantially free from solvents and/or azeotropic entraining agents and in that the water of condensation formed is removed from the gas phase of the reaction zone.
摘要:
The present invention relates to the use of water-dispersible and/or water-emulsifiable amphiphilic co-oligomer of fatty crotonates and radical-copolymerizable hydrophilic ethylenically unsaturated acids and/or anhydrides thereof which may also contain small quantities of other copolymerizable comonomers, for the oiling and optionally waterproof finishing of leathers and skins.
摘要:
An aqueous dispersion of amphiphilic co-oligomers for oiling leather or skins wherein the dispersion contains co-oligomers of(a) fatty crotonates,(b) radical-copolymerizable, hydrophilic, ethylenically unsaturated acids, anhydrides and mixtures thereof, wherein the weight ratio of (a):(b) is 30-90%:70-10%, based on the weight of (a)+(b), the dispersion having an active substance content in the range from about 30-70% by weight, based on the weight of the dispersion, and optionally(c) copolymerizable comonomers having neither a pronounced hydrophobicizing effect nor containing hydrophilicizing groups.
摘要:
The invention describes a process for the partial or complete exchange of the free radical inhibitors (preparation inhibitor) from their admixtures with free radical-reactive--and especially polymerizable and/or cross-linkable--olefinically mono- and/or polyunsaturated compounds against free radical inhibitors or inhibitor systems (application inhibitor), the kind and amount of which are freely determinable. The process according to the invention is characterized in that admixtures reactive via free radicals are employed which contain, as the preparation inhibitor, appropriate compounds of the phenol type comprising hydroxyl groups capable of forming salts, this feedstock mixture as a liquid phase is subjected to a treatment with solid oxides, carbonates and/or hydroxides of the alkali metals and/or alkaline earth metals, which may also be present in admixture with further oxidic metal compounds, thereby in a pre-determinable manner binding all or part of the preparation inhibitor to the solid phase, the resulting solid phase is separated from the liquid phase, and the content of the application inhibitor in this liquid phase is adjusted with respect to kind an amount thereof. The process is preferably applied to free radical-reactive substance mixtures, from which the preparation inhibitors contained therein cannot be satisfactorily removed by way of a distillation.
摘要:
The invention relates to a process for the production of (meth)acrylic acid esters of polyhydric alcohols by reaction thereof with acrylic acid and/or methacrylic acid in the presence of acidic esterification catalysts with addition of polymerization inhibitors to the reaction mixture. The new process is characterized in that, where unsubstituted phenolic compounds are used as inhibitors, the esterification reaction is carried out with addition of active carbon to the reaction mixture. The preferred inhibitor is hydroquinone. In addition, the esterification reaction is preferably carried out in the absence of liquid solvents and/or azeotropic entraining agents.