CS232097B1 - Method of stabilizing isotactic polypropylene - Google Patents

Abstract

The invention belongs to the field of chemistry and technology of macromolecular substances and solves the problem of UV stabilization of isotactic polypropylene. The essence of the method after. The point of the invention is that 0.14 to 0.8% by weight of secondary alicyclic amines with a sterically hindered nitrogen atom from the group of preventing substances such as 4-amino2,2,6,6-tetramethylpiperidine, dispiro (5.1.5.3)-7,15-diazohexadecane, dispiro (5.1.5.3)-14, 16-dioxo-7,15-diazahexadecane in the presence of 0.1 to 0.2% by mass. , useful antioxidants such as 2,6"di-tert-butyl-4-methyl-phenol, tris-(2,4-di-tert-butyl-phenyl)-phosphite, or tetrakis-/5-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-oxo-oxopentyl/methane and 0.15% by weight of calcium stearate. The polymer, stabilized by the method of the present invention, can find application in healthcare, food industry and wherever it is necessary to limit the extraction of chemicals from polymers.

Description

232 097

The invention relates to a method for stabilizing isotactic polypropylene.

In current methods for the stabilization of isotactic crystals of polypropylene, low molecular weight substances and copolymer materials with a built-in stabilizer in macromolecule are used. · Low molecular weight substances tend to reduce the volatility of řené fused groups, but two molecules of a single unit are linked together. Polymeric stabilizers are prepared by polymerization or copolymerization of monomers with a stabilizing effect, also by polyaddition with polycondensation, or by polymer-polymeric conversion on polymers. Low-molecular substances have the disadvantage that the polymer can escape as a result of processing as well as the use / volatility of processing. Macromolecular materials are more likely to be miscible with polypropylene into which they are blended, while the stabilizers incorporated by the polymer often lose a significant amount of their effect due to armored mobility. ktivity ·

The above-mentioned disadvantages can be overcome by the method according to the invention, wherein when the UV stabilizer is used, from 0.14 to 0.28% by weight. of secondary alicyclic amines sterically hindered by nitrogen from the backbone group and 4-amino-2,2,6,6-tetramethylpiperidine (E, dispiro (5,1,5,3) -7,15-diazohexadecane, dispir (5,1,5,3) -14,16-dioxo-7,15 "diaza-hexadecane in the presence of 0.1-0.2% by weight of antioxidants and 2,6-di-tert-butyl-4"; nonylphenol, tris- (2,4-di-tert-butylphenyl) phosphite, or tetrakis (5 ', 3,5', di-tert-butyl-4 ', hydroxyphenyl) -3-oxo-2-exopentyl / methane and 0, 15% by weight of calcium stearate is of particular importance. A 232.097 fixed stabilizer polymeric material, which is added as a concentrate of the fixed substance d® polymer prior to processing, is of particular importance if, for example, the polymeric carrier contains reactive groups at a concentration of 0.1%. mole / 100 g, at 90% epoxide conversion, the concentrate will bind 14.1 g of 4-amino-2,2,6,6-tetramethylpiperidine stabilizer in 100 g * For a 0.14 wt% stabilizer may then be mixed into polypropylene about 1% of this concentrate.

The polymeric material of the stabilized stabilizer concentrate is prepared by bonding low molecular weight inoculated isotactic polypropylene containing epoxy or chlorohydrate groups (see AO No. 218 602 and AO No. 222 090). by reacting the compound with mobile hydrogen, such as amines and acids. When Hals / secondary alicyclic amines are sosterosterated by nitrogen, they have been fixed by nitrogen in the aliocyclic ring / piperazine type or nitrogen ring / 4-amino-piperidine type / · Reaction in heterogeneous conditions take place at ambient temperatures of about 100 ° C, with more than 90% of the reactive groups of the polypropylene support being used for fixation.

When mixing the stabilizer concentrate d® polypropylene, it is necessary to work in optimum conditions to avoid mechanical destruction of the polymer, especially inoculated on polypropylene. Higher working temperatures are recommended at which the melt viscosity is lower and shorter mixing times. The bound stabilizer is not cleaved from the polymer even at higher processing temperatures for isotactic polypropylene. By thermal analysis of the concentrate, it has been shown that the polypropylene containing the UV stabilizer according to the invention is thermally decomposed by a higher-pressure polymer. The stabilizer cannot be washed from the polymer or washed in water with the emulsifier if it has been sampled in pH 11 at 90 ° C for 50 hours.

The method of stabilizing polypropylene with chemically fixed HALS-type low molecular weight compounds is described in the following examples, but is not limited to these examples.

The Brabender OV plastic mix was mixed at 190 ° C for 10 min under nitrogen with a mixture of 0.43 parts by weight of a copolymerized polypropylene containing 0.05 parts by weight of bonded 4-amino-2,2,6,6-tetramethylpiperidine, 0.07 the weight of the tris- / 2,4-diterobutylphenyl-phosphite, 0.05 weight parts of calcium stearate and 35.45 weight parts of the unstabilized isotactic polypropylene powder. * pressure 19.6 MPa for foil foil 0.5 mm * Foil strips can be solved into Xeneteet 450 and at certain time intervals by 1S analysis. From the graphical record, the induction period in hours was evaluated, during which the absorbance of the carbexyl groups of the polypropylene was 0.3. At the same time, 5 parallel samples were measured and the arithmetic center of the induction period was determined. Under the same conditions, reference samples containing no HALS-type fixed UV stabilizer were subjected to the Xenotes. Examples of UV stabilization of polypropylene are summarized in Tab. 1 retouching procedure in example 1 »

By the method of stabilizing the isotactic polypropylene of the present invention, the induction periods of the carbonyl groups of the polypropylene in the Xenoteste 450 are increased from 600 to 7,000 hours.

According to the data in Table 1, the most suitable substance in the form of stabilized polypropylene according to the invention is 4-amino-2,2,6,6-tetramethylpiperidine * Preference is also given to the use of 2,6-diterebutyl-4-methylphenol resp. tris- (2,4-diterobutylphenyl) phosphite, both with calcium stearate. The theoretical basis for this choice is not known to be simple. However, it can be demonstrated that the influence of the various constituents of the system, in this case the presence of the thermo-stabilizing system, must be taken into account in the context of the stabilizer under consideration. 1, only those examples are shown, 232,097 where an induction period of over 2 * 100 hours is achieved, the value obtained in the presence of 0.3% by weight of commercial low molecular weight stabilizer 2-hydroxy-4-octyloxybenzophenone s0, 1% tetraki 3 - [5- (3,5 ** di-tert-butyl-4 '* hydroxyphenyl) -3-oxo-2-oxapentyl] methane, 0,15% 2,6-di-tert-butyl-4-methylphenol and 0,35 % Of 2,6-di-tert-butyl-4-methylphenol and 0.15% of calcium stearate and for comparison, a stabilization level. 232,097 3

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And 'Honors and £

Tab. 1 Examples of stabilization of polypropylene by fixed substances according to X · a and A o and o44 Μ φ O A oo oo cr <x O O f ~ o <o 006 o o t- 8 c- Ό Ν Φ A. > k h Φ 0 'and A A and XI> o 44 a and o. O 44 pooooo Ή H aooooooo © o o · o o o o o o o o o o o o o o o o o CM CM CM X X * 10000 xiOO O 1 1 c <x aM i '3 φχ-Χ + 3 PA Φ 1 aa 1 IIX »P rrj Cf- ^ s. P '> with 1 AM · r φ i Μ- IA Μ- Μ- and OAI (XAA A © A Ι ι> o M m A »! >> f> j A (4 ra AA a K o ir F * s Φ O Fs J> with NPAP · * -> and PPAPPAA "^ 3 1 Η A 3 A" ^ 3 3 AA 1 XA ixa XAA t XAXAA 1 A © OXF> 5 ^ O Θ IAO © O © XM "rj ma 1 XJ M and M- S mamaa φ φ ffl to φ * a OJ OJ OJ AM AM AM AM AM AM AM AM AM AM A A A A AAAA oA 1 AA Ps (0A 1 A ř 1 AA f> s -A 44 ra >> IP 1 P «5 p >> 1 p IP PAPX Φ PPK k Φ AP k0 Φ« 0 φ va h 3 * S * 3 O * and M 3 *? Gl APXN 1 PX 1 CM 1 PX CM T 00 1 «M- 00 P Μ - 00 O 0 A CM Α CM O (XB» · * »CM CM CM xt OOOO n« > 1 1 141 141 141 141>>>>>>>>>>>>>>>>>>>>>> 1 ap ap ap * * '> 1 1 «a A A A A A A A A A A A A A A A A A © © © © © © © © © © © © and M apa cm p λ A 1 AANA p 'and 1 * Φ A CM IX λ · a Pm ® A Μ · MP ft and A ra M- and A * «Ο- Ι A A A Q 1 1 a a A 44 M i!

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CM P®curr. tab. The stabilizing agent was fixed to isotactic powdered polypropylene grafted with 2,3-epoxypropylme with a acrylate containing 1.5% by weight of epoxy oxygen and through epoxide groups. Such a stabilizer concentrate was blended into the polypropylene in an amount required to produce a given concentration in the polypropylene. The induction periode was evaluated during the test sample run in the Xeno-test 450. It was evaluated by 10 analysis in hours for the absorption of the carbonyl groups in the sample equal to 0.3.

In addition, the system contained calcium stearate / 0.15 wt% /

Sample without fixed UV stabilizer

Another factor that is important for the function of the fixed stabilizer is its good miscibility with polypropylene, allowing its good dispersion in the polymer system. It is tasty because the substance does not have sufficient migration in the polymer and produces local concentrations. If the substance is bonded to a copolymer that forms part of the polypropylene, as described herein, its incorporation into polypropylene is facilitated. .

By mixing the fixed stabilizer into the polymer in the amount needed for its expected light stability, a valuable polymer is prepared that satisfies in addition the ecological aspect. The stabilizer does not leak out of it either when it is being used or when it is being used. Polymers of this type are. also suitable for use in the medical, food processing and, where ever more, standards of extraction of chemicals from polymers are required. Therefore, the tendency to solve all polymer constituents in fixed form is at most current. The synthesis would be aided by the synthesis of compounds with a combined special effect, the activity of which would not fall below a certain level or in fixed form.

Claims (1)

OBJECT OF THE INVENTION A method of stabilizing isotactiocylene polypropylene, characterized in that 0.14 to 0.28% by weight of secondary allylcic amines having a sterically hindered nitrogen atom from the group of the 4-amine-2,2,6,6- tetramethylpiperidine-4, dispiro (5,1,5,3) -7,15-diazohexadecane, dispiro (5,1,5,3) -14,16-dioxo-7,15-diazahexadecane in the presence of 0.1 to 0.2 % by weight of antioxidants such as 2,6-di-tert-butyl-4-methylphenol, tris- (2,4-di-tert-butylphenyl) -phosphite, and / or tetrakis- [5- (3,5-di-tert-butyl-4-hydroxyphenyl) -3-OX®] -2-x0-pentyl / methane and 0.15% by weight of calcium stearate.