• 1) New fluorine-containing compounds having polyacetalic structure, of general formula:
  
  
  
  
  
  
  
          (I)   [Rf-CH₂O(CH₂O)_c-CH₂⁆_n
  
  
  
  
  
  
  
  where:
  
  Rf = a perfluorooxyalkylene chain having $\overline{\text{M}}$n from 500 to 5,000;
  
  c = 1 - 10;
  
  n = 2 - 100.
• 2) A process for preparing them, which comprises carrying out the polycondensation of diols having formula:
  
  
  
  
  
  
  
          (II)   HOCH₂RfCH₂OH
  
  
  
  
  
  
  
     with formaldehyde, in mass or in the presence of solvents, in an acid medium.

The compounds of formula (I) can be oligomeric compounds (polymerization degree $\overline{\text{x}}$_n from 2 to about 20) or polymeric compounds ($\overline{\text{x}}$_n from about 20 to about 100). They exhibit a high stability to heat and to chemical agents, and Tg values slightly different from the ones of the diols utilized for preparing them.

Procédé de couplage d'un polymère vivant contenant des unités (meth)acryliques terminales vivantes qui comprend les étapes de:

• (i) polymérisation anionique à l'aide d'un système initiateur constitué par un amorceur fonctionnel et un ligand afin d'obtenir un polymère vivant contenant des unités (meth)acryliques terminales vivantes;
• (ii) réaction avec un composé aldéhyde de formule:
  
  
  
          R-(CHO)_r
  
  
  
  dans laquelle r ≧ 2; et
• (iii) récupération du polycondensat final par des moyens connus en eux-mêmes.

L'invention concerne la synthèse de copolymères à blocs constitués de blocs de poly(oxyméthylène-Co- oxyéthylène) et des blocs d'un terconstituant, ayant des propriétés de résistance à la chaleur, aux chocs et compatibles avec d'autres polymères tels que les élastomères.

A thermoplastic graft copolymer which has both excellent characteristics as an engineering plastic and biodegradability and wherein mono- or polysaccharide is made thermoplastic. This copolymer comprises a mono- or polysaccharide having functional groups selected from among hydroxyl, carboxyl, amino and amide groups and a polyacetal composed of repeated oxymethylene units, (̵CH₂O)̵, bonded to each other by reaction via the functional groups; has a structure wherein the mono- or polysaccharide units serve as the backbone and the polyacetal units serve as the branch to be grafted onto the backbone; and has a viscosity number of 0.1 to 10 dl/g and a melting point of 150 to 175 °C. It can be utilized in a wide application range including films, sheets, electric and electronic components, and automotive parts, and gives moldings which are biodegradable after being discarded, so that it has a remarkably high industrial value.

Die Erfindung betrifft ein Verfahren zur Herstellung von kationischen Lackbindemitteln, welche besonders zur Formulierung von Pigmentpasten für kathodisch abscheidbare Elektrotauchlacke geeignet sind.

Die erfindungsgemäß hergestellten Lackbindemittel sind modifizierte Epoxidharz-Amin-Addukte, die Titan in organisch-chemischer Bindung enthalten.

Auch ohne Mitverwendung von bleihaltigen Verbindungen und/oder Bleipigmenten zeigen die gehärteten Lackfilme einen ausgezeichneten Korrosionsschutz auf nicht vorbehandeltem Stahlblech.

A silicon-containing polyacetal copolymer comprises silicone oil units having the formula (A) and polyacetal units: (wherein R₁ stands for alkyl or phenyl group; R₂, a divalent organic group; X, a group selected from among -NH₂, -OH, R₄OH, R₅COOH, R₆COOR₇, -R₈ and -OR₉, R₃ representing a divalent organic group, R₄ ∼ R₆ alkylene groups with number of carbon atoms 1∼ 10, R₇ ∼ R₉ alkyl groups with number of carbon atoms 1 ∼ 10, and n a number of 5 ∼ 1000).