DE681374C - Process for stabilizing polyvinyl ethers - Google Patents

Description

Process for stabilizing polyvinyl ethers It has been shown the polyvinyl ether, although they are usually at a lower temperature and not with oxygen-releasing agents, but with acidic condensation agents, such as aluminum chloride, boron fluoride, sulfur dioxide and the like, are made against Aging are more or less sensitive. Even after careful removal the last remnants of PolymerisatIonsmittel and when completely neutralized by heating them in the air for a long time or under the action of light and air Gradually degraded.

It has now been found that by adding small amounts substances with an antioxidant effect. can provide increased resistance. Nice very small amounts of antioxidant substances prevent degradation; the Polyvinyl ether and the products show when stored as when exposed to heat or active rays of light are completely constant, so are made by these substances .stabilized in a certain sense.

Particularly suitable additives are those that contain amine, sulfide or have aromatic hydroxyl groups. You can also choose one of the groups mentioned contain several or more of these groups at the same time. As suitable stabilizers Examples include: di- (2-oxy-5-butylphenyl) sulfide or disulfide, phenyl (3-naphthylamine or condensation products of aldol and α-naphthylamine. Likewise are suitable Polymerization products which contain one or more of the above groups in the molecule included, e.g. B. polyvinyl ethyl sulfide, polyvinyl butyl sulfide u @ sw.

Often an addition of a few tenths of a percent of the relevant amount is sufficient Fabrics; However, larger amounts of them can also be used.

The stabilizers can be the polyvinyl ethers in solid form or added in solution. It has proven to be quite beneficial when using it of stabilizers containing sulfide groups have been shown to be vinyl ethers to be added before the polymerization.

Example t roo parts by weight of polyvinyl isobutyl ether, which was obtained by polymerizing highly purified vinyl isobutyl ether with boron fluoride at -45 ', are dissolved in 400 parts by weight of cyclohexane and 0.8 parts by weight of di- (2-oxy-5-butylphenyl) disulfide are added to this solution. By pouring the solution onto a. flat surface and evaporation of the solvent, a film is obtained which can be exposed to a temperature of 100 ° for 100 hours without changing. One in the same way without the addition of the di (2-oxy-5-buty1-phenyl ) -disu, ifid's produced film has become sticky and dissolves already after iz hours under the same conditions: -: The same effect can also be seen with other polyvinyl ethers, e.g. polyvinyl ether After the addition of di- (2-oxy-5-butylphenyl) disulfide, film made of this practically retained its toughness after aging for 5 hours at 95 "and cooling, while the comparison sample without this addition was very sticky and balsam-like. EXAMPLE z A mixture of 100 parts by weight of vinyl isobutyl ether, 0.4 parts by weight of di- (2-oxy-5-bu2ylphenyl) disulfide and zoo parts by weight of liquid propane is mixed with 100 parts by weight of liquid propane, through which a physical stream of gaseous fluoride fluoride is added for a short time long headed. : After the polymerization has taken place, the gelatinous mass is covered with water to which a little ammonia has been added. After the propane has evaporated, the spongy mass obtained is washed out with water on the calender, rolled out and dried in the air at 4.o °. To test, a sample is exposed to air for 50 hours at a temperature of go °. After cooling, the product shows unchanged elasticity and strength, while a product produced in the same way without the addition of the stabilizer already became very tacky under the same test conditions.

Claims (1)

hATCNTANSPRUCII: Process for the stabilization of polyvinyl ethers, characterized in that they are given small amounts of antioxidant substances clogs.