Prestabilization of halogen-containing polymers

1. A process for preparing a stabilized suspension/emulsion PVC polymer comprising

(1) adding a polymer thermal stabilizer mixture compatible with the polymerization medium prior to, during or directly after the polymerization, prior to the isolation of the polymer from the polymerization medium, wherein the polymer thermal stabilizer mixture comprises:

a) a perchlorate compound or salt thereof, and

b) an alkanolamine of the formula (I)

where

x=1, 2 or 3;

y=1, 2, 3, 4, 5 or 6;

n=from 1 to 10;

R 1 , R 2 =independently of one another, H, C 1 -C 22 -alkyl, —[—(CHR 3 a ) y —CHR 3 b —O—] n —H, —[—(CHR 3 a ) y —CHR 3 b —O—] n —CO—R 4 , C 2 -C 20 -alkenyl, C 2 -C 18 -acyl, C 4 -C 8 -cycloalkyl, which may be OH-substituted in the β position, C 6 -C 10 -aryl, C 7 -C 10 -alkaryl or C 7 -C 10 -aralkyl, or when x=1, R 1 and R 2 may additionally combine with the N to form a closed 4-10-membered ring of carbon atoms and optionally up to 2 heteroatoms, or when x=2, R 1 may additionally be C 2 -C 18 -alkylene which may be OH-substituted at both β-carbon atoms and/or may be interrupted by one or more O-atoms and/or one or more NR 2 groups, or dihydroxy-substituted tetrahydrodicyclopentadienylene, dihydroxy-substituted ethylcyclo-hexanylene, dihydroxy-substituted 4,4′-(bisphenol A dipropyl ether)ylene, isophoronylene, dimethylcyclohexanylene, dicyclohexylmethanylene, or 3,3′-dimethyldicyclohexylmethanylene, and if x=3, R 1 may also be trihydroxy-substituted (tri-N-propyl isocyanurate)triyl;

R 3 a , R 3 b =independently of one another, C 1 -C 22 -alkyl, C 2 -C 6 -alkenyl, C 6 -C 10 -aryl, H or CH 2 —X—R 5 , where X=O, S, —O—CO— or —CO—O—;

R 4 =C 1 -C 18 -alkyl/alkenyl or phenyl, and

R 5 =H, C 1 -C 22 -alkyl, C 2 -C 22 -alkenyl or C 6 -C 10 -aryl;

or salt thereof: and

(2) adding to the pre-stabilized PVC polymer, after isolation of the polymer from the polymerization medium, one or more additives selected from the group consisting of heat-stabilizers, UV stabilizers, lubricants, plasticizers, pigments, fillers, metal soaps, antioxidants, wetting agents, optical brighteners, and antisettling agents.

2. The process of claim 1 wherein the polymer thermal stabilizer mixture comprises at least a) a perchlorate compound or salt thereof and b) a reaction product of a mono- or polyfunctional epoxide and ammonia or, respectively, a mono- or polyfunctional dialkyl(aryl)- or monoalkyl(aryl)amine, or salt thereof.

3. The process of claim 2 , wherein the polyfunctional epoxide is dicyclopentadiene diepoxide, vinylcyclohexene diepoxide, bisphenol A diglycidyl ether or trisglycidyl isocyanurate and the dialkylamine is diethanolamine or diisopropanolamine and the monoalkylamine is monoethanolamine or monoisopropanolamine.

4. The process of claim 1 wherein the perchlorate salt is a compound of the formula M(ClO 4 ) n , where M is H, Li, Na, K, Mg, Ca, Sr, Ba, Zn, Al, La, Ce or NH 4 and n is either 1, 2 or 3 as required by the valency of M.

5. The process of claim 1 wherein, in the compound having the general formula (I), R 3 a and R 3 b , independently of one another, are H or CH 3 and y=1.

6. The process of claim 1 wherein, in the compound having the general formula (I), R 1═ R 2 ═CH 2 —CHR 3 b —OH.

7. The process of claim 4 wherein, in the perchlorate salt, M=Na or K and n=1.

8. The process of claim 1 wherein the compounds of the general formula (I) are selected from the group consisting of tris(2-hydroxy-1-propyl)amine, tris(2-hydroxy-ethyl)amine, bis(2-hydroxyethyl)-2-hydroxy-1-propylamine, alkyllalkenylbis(2-hydroxyethyl)amine, alkyllalkenyl(2-hydroxy-1-propyl-)-amine, N-(2-hydroxyhexadecyl)diethanolamine,-2-hydroxy-3-octyloxypropyl)-diethan-olamine, N-(2-hydroxy-3-decyloxypropyl)diethanolamine, and mixtures of these.

9. The process of claim 1 wherein the polymer thermal stabilizer mixture is comprised of from 0.01 to 3.00 parts by weight of sodium perchlorate and/or from 0 to 8.00 parts by weight of alkanolamines of the general formula (I) and/or from 0.01 to 5.00 parts by weight of the salts of a) and b), per hundred parts of polymer.

10. The process of claim 1 further comprising the step of subsequently stabilizing the polymer using conventional stabilizers and/or additives.

11. A process for preparing a stabilized suspension/emulsion PVC polymer comprising

(1) adding a polymer thermal stabilizer mixture compatible with the polymerization medium prior to, during or directly after the polymerization, prior to the isolation of the polymer from the polymerization medium, wherein the polymer thermal stabilizer mixture comprises:

a) a sodium perchlorate compound or salt thereof, and

b) an alkanolamine selected from the group consisting of tris(2-hydroxy-1-propyl)amine, tris(2-hydroxy-ethyl)amine, bis(2-hydroxyethyl)-2-hydroxy-1-propylamine, alkyllalkenylbis(2-hydroxyethyl)amine, alkyllalkenyl(2-hydroxy-1-propyl-)-amine, N-(2-hydroxyhexadecyl)diethanolamine,-2-hydroxy-3-octyloxypropyl)-diethan-olamine, N-(2-hydroxy-3-decyloxypropyl)diethanolamine, and mixtures of these; and

(2) adding to the pre-stabilized PVC polymer, after isolation of the polymer from the polymerization medium, one or more additives selected from the group consisting of heat-stabilizers, UV stabilizers, lubricants, plasticizers, pigments, fillers, metal soaps, antioxidants, wetting agents, optical brighteners, and antisettling agents.