Associations for stabilizing vinyl resins

Abstract

This invention relates to new associations of a compound of the formula: ##STR1## wherein R.sub.1 and R.sub.2 represent a hydrogen atom, an alkyl, alkoxy or hydroxy radical and R represents a hydrogen atom or an alkyl or alkoxy radical, and of a compound of the formula: ##STR2## wherein R.sub.3 represents an alkyl, alkenyl, alkynyl or aralkyl radical or a radical of the formula R.sub.4 --O(CH.sub.2).sub.n --, wherein R.sub.4 represents an alkyl or phenyl radical and n is 2, 3 or 4.The associations according to the invention are stabilizers for vinyl resins.

Description

The invention relates to associations of products useful as stabilizers for vinyl resins.

The associations according to the invention are mixtures of an indole derivative of the general formula: ##STR3## wherein R.sub.1 and R.sub.2, which are the same or different, each represent a hydrogen atom, a branched- or straight-chain alkyl or alkoxy radical containing from 1 to 12 carbon atoms or a hydroxy radical, R represents a hydrogen atom or a branched- or straight-chain alkyl or alkoxy radical containing from 1 to 4 carbon atoms, and of a dihydropyridine of the general formula: ##STR4## wherein R.sub.3 represents a branched- or straight-chain alkyl radical containing from 1 to 22 carbon atoms, a branched- or straight-chain alkenyl or alkynyl radical containing from 3 to 11 carbon atoms, an aralkyl radical optionally substituted on the para- or ortho-position by a halogen atom or by a methyl or methoxy radical, a radical R.sub.4 --O(CH.sub.2).sub.n --wherein n is 2, 3 or 4 and R.sub.4 represents a branched- or straight-chain alkyl radical containing from 1 to 4 carbon atoms or a phenyl radical.

The compounds of formula I are known, having been described in British Pat. Nos. 1,487,659 and 1,489,685, and have been prepared by the processes described in said patents.

The compounds of formula II have been described in French patent applications Nos. 77 30991 and 77 30992 and have been prepared by the processes described in said patent applications.

Vinyl resins are known to deteriorate under the influence of heat and it is necessary to add a stabilizing agent to these masses of synthetic materials in order to retard thermodegradation and thus delay coloration of the resin.

Vinyl resins are also known to deteriorate under the influence of sunlight and a change in the original coloration may result therefrom.

This problem is particularly important where containers for food and drink are concerned. It is readily appreciated that food and drink could not be packed in containers of which the coloration may change in course of time.

The problem is the same with regard to floor-coverings, of which the coloration must also remain stable for a long period of time.

It is for these reasons that stabilizers which are both thermostabilizers and photostabilizers are specially recommanded for vinyl resins.

According to the British patents and the French patent applications cited hereabove, compounds of formulae I and II have stabilizing properties and are more specially intended for the thermostabilization of resins used for manufacturing containers for food and drink.

Surprisingly, it has been found that by associating a compound of formula I with a compound of formula II, a potentiation of the stabilizing power of each molecule is obtained.

This discovery is very important since it may be reasonably expected that the same stabilizing power may be obtained by using smaller quantities of each product when associated than when used alone.

This possibility of using smaller quantities of stabilizing agents is a definite asset as far as plastic containers for food and drink are concerned.

Besides the lower cost-price obtained, it should be emphasized that when the concentration in stabilizer is lower, the amount of stabilizer extracted by the food or drink will also be lower.

This fact becomes particularly important when the restrictive trends of the various national legislation with regard to food and drink are considered.

It may be stated, as an example, that the associations of the invention already exert a good stabilizing power when they are introduced in a vinyl resin in the proportion of 0.01 to 0.3 part per hundred parts of resin (p.h.p.r.), the proportion of each constituent being generally lower than 0.2 p.h.p.r. and may at times lie between 0.01 and 0.1 p.h.p.r.

In the associations according to the invention, the ratio by weight between the compounds of formula I and those of formula II will generally be between 0.05 and 1 and preferably between 0.1 and 1. This ratio may however be equal to 1 or be between 1 and 20.

It has also been found that the associations of the invention possess a photostabilizing power which is far from negligible resulting in better resistance of the resin to sunlight, i.e. in a reduction, or at certain concentration the inhibition of the tendency to darken.

This is an important advantage over the compounds of formula I, which do not prevent the vinyl resin from deteriorating under the influence of light, especially when the resin is left to stand in bright sunlight.

It is known from the above-mentioned patents and patent applications that the compounds of formulae I and II have low acute toxicity, the LD.sub.50 (the dose of substance which provokes the death of 50% of the treated animals) being over 2 g/kg by oral route in mice. It may, therefore, be concluded that the associations of the invention will not create any problem of toxicity and that their use for stabilizing containers for food and drink may be envisaged.

In addition, the associations of the invention present the following advantages:

They are very valuable anti-oxidant agents

The constituents of the associations do not sublimate or they present a fairly low degree of sublimation, an advantage which is important with regard the manipulation of the compounds in industry. The associations of the invention do not therefore present any problem with regard to the health and security of those called upon to handle them.

For greater ease in expressing the results of tests, the following references have been attributed to the constituents of the associations according to the invention.

______________________________________Compounds of formula I Code______________________________________2-Phenyl-indole S 36212-(4'-Dodecyl-phenyl)-indole S 36282-(3'-Methoxy-4'-hydroxy-phenyl)-indole S 36302-(3'-Methyl-4'-methoxy-phenyl)-indole LCS 260842-Phenyl-5-methoxy-indole LCS 260032-(3'-Dodecyl-4'-methoxy-phenyl)-indole LCS 261622-(3',4'-Diethoxy-phenyl)-indole LCS 261772-(3'-Methoxy-4'-propoxy-phenyl)-indole LCS 261782-(3'-Methyl-4'-ethoxy-phenyl)-indole LCS 261852-(3'-Methoxy-4'-ethoxy-phenyl)-indole LCS 261442-(4'-Methyl-phenyl)-indole LCS 260092-(4'-Methyl-phenyl)-5-methyl-indole LCS 26035______________________________________ ______________________________________Compounds of formula II Code______________________________________2,6-Dimethyl-3,5-dicarboallyloxy-1,4-dihydropyridine LCS 285112,6-Dimethyl-3,5-dicarboethoxy-1,4-dihydropyridine LCS 285012,6-Dimethyl-3,5-dicarbomethoxy-1,4-dihydropyridine LCS 285042,6-Dimethyl-3,5-dicarbododecyloxy-1,4-dihydropyridine LCS 285072,6-Dimethyl-3,5-dicarbobenzyloxy-1,4-dihydropyridine LCS 285122,6-Dimethyl-3,5-dicarbopropargyloxy-1,4-dihydropyridine LCS 285132,6-Dimethyl-3,5-di-(4'-carbomethoxy-phenoxy)-1,4-dihydropyridine LCS 285412,6-Dimethyl-3,5-di-(2'-carbophenoxy-ethoxy)-1,4-dihydropyridine LCS 285882,6-Dimethyl-3,5-dicarbobehenyloxy-1,4-dihydropyridine LCS 286012,6-Dimethyl-3,5-dicarbopalmityloxy-1,4-dihydropyridine LCS 28603______________________________________

A compound of formula II wherein R.sub.3 corresponds to the alkyl radical of DOBANOL 23 (a mixture of primary alcohols containing from 12 to 15 carbon atoms which is marketed by SHELL CHIMIE) has also been tested. This compound is designated by the code No. LCS 28597.

A. Compatibility of the compounds of formulae I and II

Before studying the potentiation of the stabilizing power of each constituent of the association of the invention, the compatibility of said constituents within a vinyl resin was checked.

It was found that by incorporating a quantity of a compound of formula II in a vinyl resin which already contained a compound of formula I, the thermostabilization of the resin was markedly increased.

The study of the thermostability of the following resin was carried out according to the GARDNER method described in British Pat. No. 1,489,685:

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin 100Antishock agent 11Acrylic resin 0.5Epoxide soja bean oil 3.0Zinc stearate 0.125Calcium stearate 0.3Stabilizer of formula I 0.1Stabilizer of formula II 0 or 0.2______________________________________

The sheets were placed in a ventilated oven at 185.degree. C. and were removed at fixed intervals of time. Their coloration were expressed in terms of the reference figures of the GARDNER scale.

The following results were obtained:

__________________________________________________________________________Stabilizer of Stabilizer of Time in minutesformula I formula II 0 10 20 30 40 50 55 60 75__________________________________________________________________________S 3630 -- 1 >1 <2 <3 <4 4 >4 >4 11S 3630 LCS 28511 1 1 >1 <2 <2 3 <4 <4 5LCS 26084 LCS 28511 1 1 1 >1 >1 <2 2 >2 4LCS 26162 LCS 28511 1 1 1 >1 >1 <2 2 >2 4LCS 26177 LCS 28511 1 1 1 >1 >1 <2 2 >2 >4LCS 26178 LCS 28511 1 1 1 >1 >1 <2 2 >2 4LCS 26185 LCS 28511 1 1 1 >1 >1 <2 2 >2 4LCS 26144 LCS 28511 1 1 1 >1 >1 <2 2 >2 5__________________________________________________________________________S 3630 -- 1 >1 <2 < 3 <4 4 >4 >4 11S 3630 LCS 28501 1 1 >1 >1 <2 3 >3 <4 5LCS 26084 LCS 28501 1 1 >1 >1 >1 <2 3 >3 4LCS 26162 LCS 28501 1 1 1 >1 >1 <2 3 >3 5LCS 26177 LCS 28501 1 1 1 >1 >1 <2 <3 3 4LCS 26178 LCS 28501 1 1 1 >1 <2 >2 <4 4 5LCS 26185 LCS 28501 1 1 1 >1 >1 <2 <3 3 4LCS 26144 LCS 28501 1 1 1 >1 >1 <2 <3 3 5__________________________________________________________________________S 3630 -- 1 >1 <2 <3 <4 4 >4 >4 11S 3630 LCS 28504 1 1 >1 >1 <2 3 >3 <4 5LCS 26084 LCS 28504 1 1 1 >1 >1 <2 3 3 4LCS 26162 LCS 28504 1 1 1 >1 >1 2 >3 >3 >5LCS 26177 LCS 28504 1 1 1 >1 >1 <2 3 >3 4LCS 26178 LCS 28504 1 1 1 >1 >1 <2 <3 3 <4LCS 26185 LCS 28504 1 1 1 >1 >1 <2 <3 3 5LCS 26144 LCS 28504 1 1 1 >1 >1 <2 <3 3 >5__________________________________________________________________________ The above results show the perfect compatibility of the compounds of formulae I and II since the addition of a compound of formula II to a resin containing already a compound of formula I increases in a constant manner the stabilizing effect of this latter compound.

The influence of a quantity of a compound of formula II (LCS 28504) on the thermostabilization of a resin containing 0.3 part by weight of a compound I (S 3630) was also studied.

The sheets were placed in an oven at 185.degree. C. for 80 minutes and in a Metrastat oven at 210.degree. C. for 60 minutes, and their coloration was expressed in terms of the reference figures of the GARDNER scale at fixed intervals of time.

The results hereunder were obtained with the following resin:

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin 100Antishock Agent 10Acrylic resin 0.5Epoxide soja bean oil 3.0SL 2016 0.1Zinc and calcium stearates 0.2Hydrogenated rape-seed oil 1.5Polyethylene wax 0.3S 3630 0.3LCS 28504 0 to 0.5______________________________________

SL 2016 is a solution of zinc 2-ethyl-hexanoate in a mixture of aromatic hydrocarbons boiling between 158.degree. C. and 184.degree. C.

______________________________________(1) Oven at 185.degree. C.p.h.p.r.of LCS28504 by Time in minutesweight 0 10 20 30 40 50 60 70 80______________________________________0 1 >1 >1 2 2 <4 4 >4 50.1 1 1 1 >1 <2 >2 3 <4 40.2 1 1 1 >1 >1 <2 <3 3 <40.3 1 1 1 >1 >1 2 <3 3 >40.5 1 1 1 >1 >1 >2 3 3 4______________________________________ ______________________________________(2) Metrastat oven at 210.degree. C. Time in minutesp.h.p.r. of LCS 0 to 10 to 20 to 30 to 35 to 40 to28504 by weight 10 20 30 35 40 60______________________________________0 1 1 >1 >3 >5 Burnt at 41 min.0.1 1 1 >1 2 4 B. at 40 min.0.2 1 1 >1 2 4 B. at 40 min.0.3 1 1 >1 2 4 B. at 40 min.0.5 1 1 >1 >2 4 B. at 40 min.______________________________________

The above results not only confirm that the addition of LCS 28504 increases the stabilizing effect of S 3630, but also that LCS 28504 presents a maximum effect even at the lowest concentrations, since the stability of the resins is practically the same for all concentrations in LCS 28504

B. Results of the Thermostability Study

(a) Stabilization of Polyvinyl Chloride

(1) Associations

S 3630-LCS 28504 and S 3621-LCS 28504

This study and the following were carried out according to the GARDNER method. The sheets were heated at 210.degree. C. in an oven for 21 minutes and their colorations were determined every 3 minutes.

The following compound was prepared:

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin 100Antishock agent 8Epoxide soja bean oil 4Acrylic resin 0.5Trinonylphenyl phosphite 0.3SL 2016 0.25Calcium behenate 0.4Glyceryl trimontanate 0.4Hydrogenated rape-seed oil 1.2Stabilizer 0.3______________________________________

The following results were obtained:

__________________________________________________________________________Stabilizers Time in minutesS 3630 S 3621 LCS 28504 0 3 6 9 12 15 18 21__________________________________________________________________________0 0 0.3 1 1 >1 2 >3 5 Burnt --0.3 0 0 1 >2 >2 3 4 >5 >5 Burnt0.15 0 0.15 1 1 .gtoreq.1 .ltoreq.2 .ltoreq.3 4 5 Burnt0 0 0.3 1 1 1 2 3 7 Burnt --0 0.3 0 1 2 .ltoreq.3 .gtoreq.3 .gtoreq.3 4 8.5 Burnt0 0.25 0.05 1 1 2 3 3 4 8 Burnt0 0.20 0.10 1 1 2 .gtoreq.2 3 .gtoreq.4 Burnt --0 0.15 0.15 1 1 .ltoreq.2 .gtoreq.2 3 4 Burnt --0 0.10 0.20 1 1 .ltoreq.2 .gtoreq.2 4 .gtoreq.4 .gtoreq.5 Burnt__________________________________________________________________________

The above results show the marked superiority of the associations of the invention over each constituent of said associations used alone at equivalent concentrations.

(2) Associations

S 3630-LCS 28507 and S 3630-LCS 28511

The following compound was prepared:

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin 100Antishock agent 5Epoxide soja bean oil 8Trinonylphenyl phosphite 1Calcium behenate 0.3SL 2016 0.15Hydrogenated rape-seed oil 1.2Glyceryl trimontanate 0.4Polyethylene wax 0.15Stabilizer 0.2 0r 0.1______________________________________

The sheets were heated at 210.degree. C. in an oven after having been processed on cylinders at 200.degree. C.

The following results were obtained:

______________________________________Stabilizers LCS Time in min.S 3630 LCS 28507 28511 0 3 6 9 12 15 18______________________________________0.2 0 0 1 1 1 1.5 3 4.5 60.1 0.1 0 1 1 1 1.5 3 4 50 0.2 0 <3 <3 <3 3 4.5 5 60.1 0 0 1 1 1 2 3 5 60.05 0 0.05 1 1 1 1.5 2 4 50 0 0.1 1 1 1 1.5 2.5 4.5 6______________________________________

The above results clearly show the potentiation of the stabilizing power of each constituent of the associations of the invention.

(3) Associations

S 3630-LCS 28504

The stabilizing power of the associations of the invention on resins of high K wert (66 to 67) was also studied:

The following compound was prepared:

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin (K wert = 66) 100Antishock agent 5Epoxide soja bean oil 8Trinonylphenyl phosphite 1Calcium behenate 0.3SL 2016 0.15Hydrogenated rape-seed oil 1.2Glyceryl trimontanate 0.3Polyethylene wax 0.15Stabilizer 0.1______________________________________

The sheets were heated at 210.degree. C. in an oven and the following results were obtained:

__________________________________________________________________________Stabilizers Time in minutesS 3630 LCS 28504 0 3 6 9 12 15 18 21 24 27 30__________________________________________________________________________0 0 1 1 1 2 .gtoreq.2 .gtoreq.3 4 7 8.5 11 Burnt0.1 0 1 1 1 1 2 .gtoreq.2 .ltoreq.3 .gtoreq.5 11 B. --0.05 0.05 1 1 1 1 .gtoreq.1 .ltoreq.2 .gtoreq.2 3 .gtoreq.5 B. --0 0.1 1 1 1 .gtoreq.1 .gtoreq.2 3 5 11 B. -- --__________________________________________________________________________

The above results confirm the potentiation of the stabilizing power of the compounds forming the associations according to the invention.

(4) Associations

S 3621-LCS 28507 S 3621-LCS 28588 S 3621-LCS 28603 S3621-LCS 28512 S 3621-LCS 28541 S 3621-LCS 28597 S 3621-LCS 28601

The following compound was prepared:

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin 100Antishock agent 9Epoxide soja bean oil 2SL 2016 0.1Calcium hydroxystearate 0.2Stabilizer 0.3______________________________________

The compound was prepared at 160.degree.-162.degree. C. and the sheets were heated at 210.degree. C. in an oven.

The following results were obtained:

______________________________________Stabilizers Time in minutesS 3621 LCS 28507 LCS 28588 0 3 6 9 12 15 18______________________________________0.3 0 0 1 1 2 3 10 11 11.50.15 0.15 0 1 1 2 2.5 5 8 10.50.15 0 0.15 1 1 1 1.5 4 6 6______________________________________ __________________________________________________________________________StabilizersLCS LCS LCS LCS LCS Time in minutesS3621 28603 28512 28541 28597 28601 0 3 6 9 12 15 18 21__________________________________________________________________________0.3 0 0 0 0 0 1 1 1 3 4 11 17 --0.15 0.15 0 0 0 0 1 1 1 2 2.5 2.5 4 70.15 0 0.15 0 0 0 1 1 1 2.5 3 4 6 80.15 0 0 0.15 0 0 1 1 1 2.5 3 6 10 100.15 0 0 0 0.15 0 1 1 1 2 2.5 3 4 70.15 0 0 0 0 0.15 1 1 1 2.5 3 7 9.5 11__________________________________________________________________________

The above results show that the associations of the invention have a thermostabilizing power markedly superior that of S 3621 used alone at an equivalent concentration.

(5) Associations

S 3630-LCS 28603 S 3630-LCS 28512 S 3630-LCS 28541 S 3630-LCS 28597 S 3630-LCS 28601

The same resin as hereabove was employed. The compound was prepared at 162.5.degree. C. and the sheets were heated at 212.degree. C. in an oven.

The following results were obtained:

__________________________________________________________________________StabilizersLCS LCS LCS LCS LCS Time in minutesS3630 28603 28512 28541 28597 28601 0 3 6 9 12 15 18__________________________________________________________________________0.3 0 0 0 0 0 1 1 2 3 5 11 130.15 0.15 0 0 0 0 1 1 2 2.5 2.5 4 80.15 0 0.15 0 0 0 1 1 2 2.5 2.5 8 10.50.15 0 0 0.15 0 0 1 1 2 2.5 8 10 130.15 0 0 0 0.15 0 1 1 2 2.5 5 8.5 130.15 0 0 0 0 0.15 1 1 2 2.5 5 9.5 13__________________________________________________________________________

The above results show that the associations of the invention have a thermostabilizing power markedly superior to that of S 3630 used alone at an equivalent concentration.

Moreover, the resins stabilized with an association of the invention do not present a pink coloration at time zero, as opposed to the resin stabilized with S 3630.

(6) Associations

LCS 26003-LCS 28507 LCS 26035-LCS 28507 S 3628-LCS 28507

The same resin as hereabove was employed. The compound was prepared at 160.degree.-162.degree. C. and the sheets were heated at 210.degree. C. in an oven.

The following results were obtained:

______________________________________StabilizersLCS LCS LCS Time in minutes26003 26035 S3628 28507 0 3 6 9 12 15 18______________________________________0.3 0 0 0 1 1 1 2 3 10.5 140.15 0 0 0.15 1 1 1 1.5 4 10 10.50 0.3 0 0 1 1 1 2 4 13 140 0.15 0 0.15 1 1 1 2 4 6 110 0 0.3 0 1 1 1.5 2.5 5.5 13 140 0 0.15 0.15 1 1 1 2 5 10 11______________________________________

The hereabove associations were also found to be superior to the indole derivatives used alone at equivalent concentrations.

(7) Association: S 3621-LCS 28507

This study was carried out with different polyvinyl chloride resins but containing the same ingredients as hereabove.

The compound was prepared in a cylindrical mixer at 162.degree. C. in the first case and at 160.degree. C. in the second and the sheets were heated in an oven at 210.degree. C. in the first case and 212.degree. C. in the second.

The following results were obtained:

______________________________________Stabilizers Time in minutesS 3621 LCS 28507 0 3 6 9 12 15 18______________________________________0 0.3 1 1 1 2 3.5 10 140.05 0.25 1 1 1 2 3 6 140.10 0.20 1 1 1 2 3 7 120.20 0.10 1 1 1 2 3 6 10.50.25 0.05 1 1 1 2 3.5 10 11.50.3 0 1 1 1 2 4 10 130 0.3 1 1 1 2.5 4 10 150.05 0.25 1 1 1 2 3.5 7 140.10 0.20 1 1 1 2 3 6 110.20 0.10 1 1 1 2 3 5.5 10.50.25 0.05 1 1 1 2.5 3.5 10 120.3 0 1 1 1 2 4 10 12.5______________________________________

The above results confirm the potentiating effect obtained by associating S 3621 and LCS 28507.

(b) Stabilization of Vinyl Co-polymers

I. Co-polymer Polyvinylchloride-vinylidene Chloride

The following compound was prepared at 160.degree.-162.degree. C.

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin 90Co-polymer vinylchloride-vinylidene chloride 10Antishock agent 8Epoxide soja bean oil 4Calcium stearate 0.2Zinc stearate 0.1Hydrogenated rape-seed oil 1.2Glyceryl trimontanate 0.4Stabilizer 0.3______________________________________

The following results were obtained, the sheets have been heated at 210.degree. C./212.degree. C. in a ventilated oven:

(1) Associations

S 3621-LCS 28504 S 3621-LCS 28507

______________________________________Stabilizers Time in minutesS3621 LCS28504 LCS28507 0 3 6 9 12 15______________________________________0.3 0 0 1 1 1.5 5 14 160.2 0.1 0 1 1 1 2 9 160.15 0.15 0 1 1 1 2 8.5 160.1 0.2 0 1 1 1 2 6 100.1 0 0.2 1 1 1 4 12 150.15 0 0.15 1 1 1 3 12 15______________________________________

Besides showing the compatibility of L 28504 and L 28507 with S 3621 in a co-polymer vinyl chloride-vinylidene chloride, the above results also demonstrate the superiority of the above associations over S 3621 used alone at an equivalent concentration.

(2) Associations

S 3621-L 28511 S 3621-L 28512 S 3621-L 28513 S 3621-L 28541 S 3621-L 28588

__________________________________________________________________________StabilizersLCS LCS LCS LCS LCS Time in minutesS3621 28511 28512 28513 28541 28588 0 3 6 9 12 15__________________________________________________________________________0.3 0 0 0 0 0 1 2 2.5 4 12 160.15 0.15 0 0 0 0 1 2 2 4 9 130.15 0 0.15 0 0 0 1 2 2 3 8 120.15 0 0 0.15 0 0 1 2 2 3 8 140.15 0 0 0 0.15 0 1 2 3 3.5 8.5 110.15 0 0 0 0 0.15 1 2 3 3.5 8.5 14__________________________________________________________________________

The above associations are also superior to S 3621 used alone at an equivalent concentration. Moreover, the resins stabilized with the hereabove associations do not present a pink coloration at time zero, as opposed to the resin stabilized with S 3621.

(3) Associations

S 3621-LCS 28597 S 3621-LCS 28601 S 3621-LCS 28603

______________________________________Stabilizers LCS Time in minutesS3621 LCS28597 LCS28601 28603 0 3 6 9 12 15______________________________________0.3 0 0 0 1 2 2.5 4 10 130.15 0.15 0 0 1 2 2 3 7 90.15 0 0.15 0 1 2 2 3 8 110.15 0 0 0.15 1 2 3 7 8 --______________________________________

The same conclusion as hereabove may be drawn.

(4) Association

L 26035-L 28507

______________________________________Stabilizers Time in minutesLCS 26035 LCS 28507 0 3 6 9 12 15______________________________________0.3 0 1 2.5 5 10.5 13 160.15 0.15 1 2 3 8 9 13______________________________________

The same conclusion as hereabove may also be drawn.

II. Co-polymer vinylchloride-vinyl acetate

The following compound was prepared at 140.degree. C.:

______________________________________Ingredients Parts by weight______________________________________Co-polymer vinylchloride-vinyl acetate 80Polyvinyl chloride resin 20Calcium stearate 0.5Stabilizer 0.20 or 0.25______________________________________

The sheets were heated at 185.degree. C. in a ventilated oven and the following results were obtained:

(1) Associations

S 3621-LCS 28504 S 3621-LCS 28507

______________________________________Stabilizers Time in minutesS3621 LCS28504 LCS28507 0 2 4 6 8 10 12______________________________________0.25 0 0 1 1 2 3 10 13 18.50.10 0.10 0 1 1 1.5 3 8 12 180.10 0.15 0 1 1 1.5 2.5 6 11 140.15 0.10 0 1 1 1.5 2.5 5.5 11 120.15 0 0.10 1 1 2 3 10 12 17.50.10 0 0.15 1 1 2 2.5 10 12 17.5______________________________________

It may be concluded that the associations of the invention have a stabilizing power superior to that of S 3621 used alone at an equivalent concentration.

(2) Associations

S 3621-LCS 28511 S 3621 -LCS 28512 S 3621- LCS 28513 S 3621-LCS 28541 S 3621 -LCS 28588

__________________________________________________________________________StabilizersLCS LCS LCS LCS LCS Time in minutesS3621 28511 28512 28513 28541 28588 0 2 4 6 8 10 12 14__________________________________________________________________________0.25 0 0 0 0 0 1 1 1 2 12 14 18.5 --0.10 0.15 0 0 0 0 1 1 1 4 10 13 16 --0.10 0 0.15 0 0 0 1 1 1 2 8 12 14 180.10 0 0 0.15 0 0 1 1 1 3 6 11.5 17 --0.10 0 0 0 0.15 0 1 1 1 1 10 12 17 180.10 0 0 0 0 0.15 1 1 1 4 10 12.5 16 --__________________________________________________________________________

These results also show that the above associations are superior to S 3621 used alone at an equivalent concentration.

(3) Associations

S 3621-LCS 28597 S 3621 -LCS 28601 S 3621-LCS 28603

(For Tests 3 and 4 the compound was prepared at 135.degree. C. )

__________________________________________________________________________StabilizersLCS LCS LCS Time in minutesS3621 28597 28601 28603 0 2 4 6 8 10 12__________________________________________________________________________0.25 0 0 0 1 1 2 3.5 11.5 12.5 150.10 0.15 0 0 1 1 2 3 10 12.5 140.10 0 0.15 0 1 1 2 3 10 12 140.10 0 0 0.15 1 1 2 3 10 11 14__________________________________________________________________________

The same conclusion as hereabove may be drawn.

(4) Association

LCS 26035-LCS 28507

______________________________________Stabilizers Time in minutesLCS 26035 LCS 28507 0 2 4 6 8 10 12______________________________________0.25 0 1 1 2 3.5 11 13 150.10 0.15 1 1 2 3 10 12 14______________________________________

The same conclusion as hereabove may be drawn.

(5) Association

S 3621-L 28504

For this trial, the following compound was prepared at 137.5.degree. C. and the sheets were heated at 185.degree. C. in a ventilated oven:

______________________________________Ingredients Parts by weight______________________________________Co-polymer vinylchloride-vinyl acetate 100Calcium stearate 0.5Glyceryl tribehenate 0.4Stabilizer 0.25______________________________________

The following results were obtained:

______________________________________Stabilizers Time in minutesS 3621 LCS 28504 0 3 6 9______________________________________0.25 0 1 3 15 --0.15 0.10 1 2 5 18______________________________________

These results confirm the superiority of the above association over S 3621 used alone at an equivalent concentration.

C. Results of the Photostability Study

The photostabilizing power of the associations of the invention was determined by exposing to the sun plates of vinyl resin and by evaluating their coloration after fixed intervals of time

(1) Polyvinyl chloride resins

(a) Associations

S 3630-LCS 28504 S 3621-LCS 28504

The following compound was prepared at 160.degree. C.

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin 100Antishock agent 8Epoxide soja bean oil 4Acrylic resin 0.5Trinonylphenyl phosphite 0.3SL 2016 0.25Calcium behenate 0.4Hydrogenated rape-seed oil 0.2Glyceryl trimontanate 0.4Stabilizer of formula I 0 to 0.3Stabilizer of formula II 0 to 0.5______________________________________

The coloration of the plates was determined according to two methods:

On the plates themselves by comparison with the GARDNER scale.

On solutions of the plates in tetrahydrofuran by comparison with the scale of colorations described in "La Pharmacopee Francaise" (9th Edition, II, 338).

The following results were obtained:

______________________________________ GARDNER FRENCH SCALE PHARMACOPEIAStabilizers Time in hours Time in hoursS3630 S3621 LCS28504 0 6 12 0 6 12______________________________________0.3 0 0 1 5 -- B4 JB3 --0.3 0 0.1 1 4 -- B4 B3 --0.3 0 0.25 1 3.5 -- B4 JB3 --0.3 0 0.5 1 3 -- JB4 JV3 --0 0.3 0 1 4 -- JV6 JB5 to -- JB40 0.3 0.1 1 3 -- JV6 J5 --0 0.3 0.25 1 2 -- JV6 J5 --0 0.3 0.5 1 1.5 -- JV6 J5 --0.3 0 0 1 10 12 B6 JB3 JB3 to JB40.25 0 0.05 1 9 10 B6 JB4 JB30.2 0 0.1 1 8 9 B6 JB3 JB30.15 0 0.15 1 7 8 B5 B4 JB30.1 0 0.2 1 5 6 B6 JB4 JB4 to JB30 0 0.3 1 1.5 1.5 JV6 JV6 JV60 0.3 0 1 4 6 JV6 JB4 J3 to J40 0.25 0.05 1 3 5 JV6 J4 J30 0.2 0.1 1 3 4 JV6 J4 J3 to J40 0.15 0.15 1 3 3 JV6 J4 J40 0.1 0.2 1 3 3 JV6 J4 JB40 0 0.3 1 1 1 JV6 JV6 JV6______________________________________

These results clearly show that the above associations have a photostabilizing power which is markedly superior to that of S 3630 and S 3621 used alone at an equivalent concentration.

(b) Associations

S 3621-LCS 28603 S 3621-LCS 28512 S 3621-LCS 28541 S 3621-LCS 28597 S 3621-LCS 28601

The following compound was prepared at 160.degree. C.:

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin 100Antishock agent 9Epoxide soja bean oil 2SL 2016 0.1Calcium hydroxystearate 0.2Stabilizer 0.3______________________________________

The following results were obtained:

______________________________________ GARDNER SCALEStabilizers Time inLCS LCS LCS LCS LCS hoursS 3621 28603 28512 28541 28597 28601 0 24 48______________________________________0.3 0 0 0 0 0 1 10 110.15 0.15 0 0 0 0 1 8 100.15 0 0.15 0 0 0 1 7 100.15 0 0 0.15 0 0 1 4 100.15 0 0 0 0.15 0 1 7 90.15 0 0 0 0 0.15 1 8 10______________________________________

It may be concluded that the associations of the invention have a photostabilizing effect on polyvinyl chloride which is markedly superior to that of S 3621 used alone at an equivalent concentration.

It should be emphasized that the conditions of exposure to sunlight were particularly severe and that the duration of photostabilization by the associations of the invention is from 20 to 60% superior to that obtained with S 3621.

Moreover, it should be noted that the GARDNER scale does not always allow a strict comparison of the real colours to be made, mainly because of the pink tints which appear in the resins. The visual aspect of the plates showed an even more marked superiority in favour of the associations of the invention.

(c) Associations

S 3630-LCS 28603 S 3630-LCS 28512 S 3630-LCS 28541 S 3630-LCS 28597 S 3630-LCS 28601

The same resin as hereabove was prepared and the following results were obtained:

______________________________________ GARDNERStabilizers SCALELCS LCS LCS LCS LCS Time in hoursS 3630 28603 28512 28541 28597 28601 0 24 48______________________________________0.3 0 0 0 0 0 1 12 140.15 0.15 0 0 0 0 1 11 120.15 0 0.15 0 0 0 1 10 110.15 0 0 0.15 0 0 1 11 120.15 0 0 0 0.15 0 1 11 130.15 0 0 0 0 0.15 1 11 12______________________________________

The same conclusions as hereabove may be drawn.

(d) Associations

LCS 26003-LCS 28507 LCS 26035-LCS 28507 S 3628-LCS 28507

The same resin as hereabove was prepared at 162.degree. C. and the following results were obtained.

______________________________________ GARDNER SCALEStabilizers Time in hoursLCS26003 LCS26035 S3628 LCS28507 0 24 48______________________________________0.3 0 0 0 1 12 140.15 0 0 0.15 1 10.5 120 0.3 0 0 1 12 140 0.15 0 0.15 1 10.5 130 0 0.3 0 1 10 120 0 0.15 0.15 1 9.5 10.5______________________________________

The associations of the invention are markedly superior to the 2-phenyl indole derivatives used alone at an equivalent concentration.

(e) Association

S 3621-LCS 28507

The same resin as hereabove was prepared and the following results were obtained:

______________________________________ GARDNER SCALEStabilizers Time in hoursS 3621 LCS 28507 0 24______________________________________0 0.3 1 10.05 0.25 1 40.1 0.2 1 50.2 0.1 1 7.50.25 0.05 1 80.3 0 1 10______________________________________

The above results show that the thermostabilization of the resin improves as the amount of LCS 28507 in the association increases.

This means that the compounds of formula II have properties which are complementary to those of the compounds of formula I, i.e. that the associations of the invention present the advantages of the compounds of formula I together with the advantages of the compounds of formula II.

(2) Vinyl co-polymers

(a) Co-polymer vinyl chloride-vinylidene chloride

The following compound was prepared at 162.5.degree. C.

______________________________________Ingredients Parts by weight______________________________________Polyvinyl chloride resin 90Co-polymer vinylchloride-vinylidene chloride 10Antishock agent 8Epoxide soja bean oil 4Calcium stearate 0.2Zinc stearate 0.1Hydrogenated rape-seed oil 1.2Glyceryl trimontanate 0.4Stabilizer 0.3______________________________________

(.alpha.) Associations

S 3621-LCS 28504 S 3621-LCS 28507

The following results were obtained:

______________________________________ GARDNER SCALEStabilizers Time in hoursS 3621 LCS 28504 LCS 28507 0 48______________________________________0.3 0 0 1 150.2 0.1 0 1 11.50.15 0.15 0 1 110.1 0.2 0 1 110.15 0 0.15 1 11.50.1 0 0.2 1 11______________________________________

The above results show a marked improvement in the photostabilization obtained by the association of the invention compared with that obtained by S 3621 used alone at an equivalent concentration. It appears that the maximum stabilization is obtained at 0.15 p.h.p.r. of LCS 28504 or LCS 28507 and that higher concentrations of these constituents do not lead to a greater degree of photostabilization of the resin.

(.beta.) Associations

S 3621-LCS 28511 S 3621-LCS 28513 S 3621-LCS 28512 S 3621-LCS 28541 S 3621-LCS 28588

The following results were obtained:

______________________________________ GARDNERStabilizers SCALES LCS LCS LCS LCS LCS Time in hours3621 28511 28513 28512 28541 28588 0 24 48______________________________________0.3 0 0 0 0 0 1 8 140.15 0.15 0 0 0 0 1 4 100.15 0 0.15 0 0 0 1 4 100.15 0 0 0.15 0 0 1 4 100.15 0 0 0 0.15 0 1 4.5 110.15 0 0 0 0 0.15 1 4 10______________________________________

These results show that the above associations are markedly superior to S 3621 used alone at an equivalent concentration.

(.gamma.) Associations

S 3621-LCS 28597 S 3621-LCS 28601 S 3621-LCS 28603

The following results were obtained:

______________________________________ GARDNER SCALEStabilizers Time in hoursS 3621 LCS 28597 LCS 28601 LCS 28603 0 24 48______________________________________0.3 0 0 0 1 8 140.15 0.15 0 0 1 4 110.15 0 0.15 0 1 4 110.15 0 0 0.15 1 4 12______________________________________

The same conclusions as hereabove may be drawn.

(.delta.) Associations

LCS 26035-LCS 28507

The following results were obtained:

______________________________________ GARDNER SCALEStabilizers Time in hoursLCS 26035 LCS 28507 0 24 48______________________________________0.3 0 1 8 140.15 0.15 1 4 4______________________________________

The same conclusions as hereabove may be drawn.

D. Study of the Extractibility of the Association of the Invention

The extractibility by water of the association of the invention was studied using two types of resin containing as stabilizer the association: S 3630-LCS 28504.

These two types of resin were:

(1) A normal compound for mineral-water bottles, containing organic salts of calcium and zinc, epoxide soja bean oil and the abovementioned association.

(2) A compound similar to the above but containing different percentages in salts and more particularly a markedly higher concentration in zinc salt.

Bottles manufactured with the above compounds were filled with water and kept in an oven at 45.degree. C. for one month.

The quantity of 2-(3'-methoxy-4'-hydroxy-phenyl)-indole (S 3630) extracted by the water was determined by colorimetric analysis with p-dimethylaminobenzaldehyde, according to the method described in Analytical Chemistry 36, 425-26 (1964).

The quantity of 2,6-dimethyl-3,5-dicarbomethoxy-1,4-dihydropyridine (LCS 28504) extracted by the water was determined by analysing this substance under the form of its oxydation product: 2,6-dimethyl-3,5-dicarbomethoxy-pyridine, according to the method described in the French patent application No. 77 30991.

The results obtained showed that the extractability of each constituent of the association is very slight, being lower than 5 .mu.g/liter.

This means that the associations of the invention can be used for stabilizing resins which are intended for manufacturing containers for food and drink.

Claims

1. New association for stabilizing vinyl resins comprising a compound of the general formula: ##STR5## wherein R.sub.1 and R.sub.2, which are the same or different, each represent a hydrogen atom, a branched- or straight-chain alkyl or alkoxy radical containing from 1 to 12 carbon atoms or a hydroxy radical, R represents a hydrogen atom or a branched- or straight-chain alkyl or alkoxy radical containing from 1 to 4 carbon atoms, and a compound of the general formula: ##STR6## wherein R.sub.3 represents a branched- or straight-chain alkyl radical containing from 1 to 22 carbon atoms, a branched- or straight-chain alkenyl or alkynyl radical containing from 3 to 11 carbon atoms, an aralkyl radical optionally substituted on the para- or ortho-position by a halogen atom or by a methyl or methoxy radical, a radical R.sub.4 --O(CH.sub.2).sub.n --wherein n is 2, 3 or 4 and R.sub.4 represents a branched- or straight-chain alkyl radical containing from 1 to 4 carbon atoms or a phenyl radical.

2. New association for stabilizing vinyl resins comprising 2-phenyl-indole and 2,6-dimethyl-3,5-dicarbomethoxy-1,4-dihydropyridine.

3. New association for stabilizing vinyl resins comprising 2-(3'-methoxy-4'-hydroxy-phenyl)-indole and 2,6-dimethyl-3,5-dicarbomethoxy-1,4-dihydropyridine.

4. New association for stabilizing vinyl resins comprising 2-(3'-methoxy-4'-hydroxy-phenyl)-indole and 2,6-dimethyl-3,5-dicarbododecyloxy-1,4-dihydropyridine.

5. New association according to claim 1 wherein the ratio by weight between the compound of formula I and that of formula II lies between 0.05 and 20.

6. New association according to claim 1 wherein the ratio by weight between the compound of formula I and that of formula II lies between 0.1 and 1.

7. Process for stabilizing a polyvinyl chloride resin whereby an association according to claim 1 is introduced into the resin in a quantity of 0.02 to 0.3 part per hundred parts of resin.

8. Process for stabilizing a vinyl chloride co-polymer whereby an association according to claim 1 is introduced into the co-polymer in a quantity of 0.02 to 1 part per hundred parts of the resin.

9. Polyvinyl chloride resin containing as stabilizer an association according to claim 1.

10. Vinyl chloride co-polymer containing as stabilizer an association according to claim 1.

11. Vinyl chloride-vinyl acetate co-polymer containing as stabilizer an association according to claim 1.

12. Vinyl chloride-vinylidene chloride co-polymer containing as stabilizer an association according to claim 1.