DE3233952A1 - Carboxamide group-containing moulding compositions or mouldings having improved resistance to the action of light - Google Patents

Abstract

The invention relates to carboxamide group-containing moulding compositions or mouldings having improved resistance to the action of light and containing, as stabiliser, a mixture of A) from 0.01 to 2.0% by weight of 1-oxa-3,8-diazaspiro[4.5]decane, and B) from 0.01 to 1.5% by weight of alkali metal salts of hypophosphorous acid, in each case based on the carboxamide group-containing plastic.

Description

Molding compositions or moldings containing carbonamide groups

It is with improved resistance to the action of light known that the mechanical properties of plastics by the influence of increased temperature, oxygen and light. As a stabilizing agent Numerous substances have become known for plastics (Thinius, Stabilisierung and aging of plastic materials, Volume 1 (1969), pages 167 to 634).

In particular, this also applies to plastics containing carbonamide groups, such as polyamides, polyester amides, polyether amides or polyether ester amides.

For the state of the art, we refer to the "Sunststoff-Handbuch", Volume IV, Polyamide (1966), pages 455 if. and page 240; for example be here called compounds which contain aromatic hydroxyl groups, such as. B.

Catechol and hydroquinone (U.S. Patent 2,598,163), p-hydroxy-benzoic acid esters (US-PS 2,597,163), 2,6-di-tert-butyl - + - alkyl-phenol (DE-AS 10 32 579). Furthermore derivatives of squaric acid (DE-AS 26 38 855, DE-AS 27 30 020, DE-AS 26 34 957).

From the German patent specification 26 06 026 is also the use of 1-oxa-3,8-diaza-spiro- [4,5] -decanes as light stabilizers for plastics known, in particular, these compounds are said to be used as light stabilizers for polyolefins be used. Finally, it is also known that the aforementioned, so-called steric hindered aromatic phenols especially together with oxygen acids des Phosphorus have a particularly favorable stabilizing effect (BE-PS 705 780?. On the other hand it has been shown that di3s is not generally valid for polyamides, but ur by choosing certain acids of phosphorus in type, amount and Induction process (DE-TS 19 19'021).

The object of the invention is to provide a stabilizer mixture, when used in plastics containing carboxamido groups, this is both improved Resistance to light results, as well as in its application not to certain Polyamides or bound to a specific process.

The problem is solved with the aid of one of the claims claimed stabilizer mixture.

Group A compounds are 1-oxa-3,8-diaza-spiro 9,52-decane, as described in German patent specification 26 06 026. In particular may be mentioned: 2,2,4,4-tetramethyl-3,20-diaza-7-oxa-21-oxo-dispiro- [5,1,11,2] -heneicosane, 2,2,4,4-tetramethyl-3,21-diaza-7-oxa-2O-oxo-diaspiro- [5,1,11,2] -henicosane.

Group B are alkali salts of hypophosphorous acid.

The sodium salts are used in particular as alkali salts, however potassium or lithium salts are also suitable.

In general, 0.05 to 1.5 percent by weight of group A is used, preferably 0.1 to 1.0, in particular 0.15 to 0.4 percent by weight and by group B 0.01 to 1.5, preferably 0.05 to 0.75, in particular 0.1 to 0.3 percent by weight one, each based on the plastic containing carbonamide groups.

Plastics containing carbonamide groups are understood to mean homo- and copolyamides of aliphatic # -aminocarboxylic acids or lactams, in particular those with at least 10 'carbon atoms or aliphatic and aliphatic dicarboxylic acids Diamines, also polyether amides, polyester amides or polyether ester amides, where as Ether component in particular. -Dihydroxy (polytetrahyarofuran) is used, or mixtures of these plastics.

In addition to the stabilizer mixtures used according to the invention, the plastics can other additives, such as pigment, dyes or plasticizers or - if desired - Contain additional stabilizers or, if appropriate, propellants.

The stabilizing agents according to the invention can be applied to known ones Way to add to the plastics. For example, this can be done before or during the polymerization or polycondensation are added to the monomers or they can be in kneaders or extrusion are kneaded into the molding compositions. But you can also have solutions the plastics are added, from which after Rltfernen the solvent z. B. powders for coating agents or foils are produced. The type of training depends here in the usual way on the type of plastic containing carboxamido groups, its manufacture or its processing.

In addition, they can be used in the molding compositions during the production of the moldings introduced or - if particularly desired - on the shaped body in a suitable manner, such as B. by tumbling or spraying in the form of a solution, are applied.

So it is possible to use stabilizers for plastics, those for the production of fibers, foils, sheets or other extruded or injection molded Serve moldings.

Plastics containing the mixtures according to the invention in stabilizing Acting amounts are particularly suitable for the production of molded parts that also the good mechanical properties with long-term exposure, especially outdoors and, associated with this, must not lose their attractive appearance.

To test the effectiveness as light stabilizers, the to products to be tested on the plastic granules drummed up and the obtained Mixture homogenized in a twin-screw extruder. The obtained in this way Granules were then pressed into 1 mm thick plates and one through the filter Exposure to sunlight-adjusted radiation. The test was carried out on cut, Approx. 1 x 3 cm large platelets by moving them in the direction of the non-irradiated side 90 ° C were bent ("Linick test"). The time to the breakage of the platelets was noted (see table).

The tests were carried out on Polylauriniactam. Tabel E.g. light stabilizer dosing irradiation additional dosing irradiation or ration use of ration *) ration Compare - (weight time up to (weight time up to E.g. T.) break T.) break (h) (h) 1 2,2,4,4-tetramethyl-3,20-diaza-0.25,566 NaH2PO2H2O 0.2 1,987 7-oxa-21-oxodispiro- [5,1,11,2] - heneicosan 1 N, N'-bis- (3- (3,5-di-tert-butyl- 0.25 102 NaH2PO2.H2O 0.2 102 4-hydroxyphenyl) propionyl) hexa- methylamine 2 octadecyl-3- (3,5-di-tert-butyl-0.25 160 NaH2PO2.H2O 0.2 160 4-hydroxyphenyl) propionate 3 pentaerythrityl-tetrakis- (3- (3.5-0.25 320 NaH2PO2.H2O 0.2 280 di-tert-butyl-4-hydroxyphenyl) - propionate) *) Water of crystallization not taken into account

Claims (1)

Claim: Molding compositions or moldings containing carbonamide groups with improved resistance to the action of light, containing as stabilizing agent (A) 0.01 to 2.0 percent by weight of 1-oxa-3,8-diaza-spiro- £ 4, -decane of the general formula (I ) or (II) in which R and R2 stand for identical or different radicals, the hydrogen atoms, alkyl or isoalkyl radicals with 1 to 30 carbon atoms or unsubstituted or substituted by halogen or an alkyl radical with 1 to 4 carbon atoms aryl radicals with 6 to 10 carbon atoms, or aralkyl radicals with 7 to 10 carbon atoms, or R1 and R2 together with the carbon atom to which they are bonded, a cycloalkyl group with 4 to 15 carbon atoms, which can also be substituted by an alkyl group with 1 to 4 carbon atoms, or the group form; R3 has the meaning of a hydrogen atom or an alkyl group with 1 to 4 carbon atoms, H - X for phosphoric acid, phosphorous acid, an aliphatic sulfonic acid or phosphonic acid with 1 to 30, or an aromatic sulfonic or phosphonic acid with 6 to 25 carbon atoms, where 1 to 3 Alkyl groups with 1 to 16 carbon atoms can be present, an aliphatic mono- or dicarboxylic acid with 2 to 34 carbon atoms or a polycarboxylic acid with up to 4 carboxyl groups and a total of up to 16 carbon atoms or an aromatic, unsubstituted or by alkyl with 1 to 4 carbon atoms substituted mono- or dicarboxylic acid with 7 to 25 carbon atoms and m = 0 or 1, and (B) 0.01 to 1.5 percent by weight alkali metal salt of hypophosphorous acid, based in each case on the plastic containing carboxamido groups.