Process for Preparing a Masterbatch of Polymer Additive

Abstract

Process for preparing a masterbatch comprising 20-90 wt % of a polymer additive dispersed in 10-80 wt % of a thermoplastic polymer, said process comprising the steps of: —providing the additive in liquid form, —optionally heating the additive, —adding solid particles of the thermoplastic polymer to the liquid additive, —heating the resulting mixture to a temperature in or above the melting temperature of the polymer, —treating the mixture with shaping equipment to form solid particles.

Claims

1. Process for preparing a masterbatch comprising 20-90 wt % of a polymer additive dispersed in 10-80 wt % of a thermoplastic polymer, said process comprising the steps of: providing the additive in liquid form, optionally heating the additive, adding solid particles of the thermoplastic polymer to the liquid additive, heating the resulting mixture to a temperature in or above the melting temperature of the polymer, treating the mixture with shaping equipment to form solid particles.

2. Process according to claim 1 wherein in the process is performed under inert atmosphere.

3. Process according to claim 1 or 2 wherein the addition of solid particles of thermoplastic polymer to the liquid additive and the heating of the resulting mixture are performed in a stirred vessel.

4. Process according to claim 3 wherein the residence time of the mixture in said vessel is at least 0.5 hour.

5. Process according to claim 4 wherein the residence time is at least 1 hour.

6. Process according to any one of the preceding claims wherein the additive is heated to a temperature in the range 80-150° C., preferably 100-130° C. prior to the addition of solid particles of thermoplastic polymer.

7. Process according to any one of the preceding claims wherein the polymer additive is selected from alkoxylated amines, amides, alkoxylated amides, glycerol esters, alkoxylated glycerol esters, and alkylated sorbitan esters.

8. Process according to claim 7 wherein the polymer additive is an alkoxylated amine having the general formula ##STR00007## wherein R.sup.1 is a saturated or unsaturated hydrocarbon chain with 11 to 21 carbon atoms, optionally substituted with —OH; —O—; —(C═O)—O—; —NH—; —Si—; —S—; —P—; —SO.sub.2—; —S═O—; or —SO.sub.3H containing groups, and R.sup.2 is independently selected from H, ethylene oxide chains, propylene oxide chains, and ethylene oxide-propylene oxide bock- or random copolymer chains, provided that at least one R.sup.2-group is other than H, and the total number of ethylene oxide and propylene oxide per chain is in the range 1-30.

9. Process according to claim 8 wherein the polymer additive is an alkoxylated monoamide having the general formula ##STR00008## wherein R.sup.1 is a saturated or unsaturated hydrocarbon chain with 11 to 21 carbon atoms, optionally substituted with —OH; —O—; —(C═O)—O—; —NH—; —Si—; —S—; —P—; —SO.sub.2—; —S═O—; or —SO.sub.3H containing groups, and R.sup.2 is independently selected from H, ethylene oxide chains, propylene oxide chains, and ethylene oxide-propylene oxide bock- or random copolymer chains, provided that not every R.sup.2 in each formula is H, and the total number of ethylene oxide and propylene oxide per chain is in the range 1-30.

10. Process according to claim 9 wherein the polymer additive is an alkoxylated bisamide having the general formula ##STR00009## wherein R.sup.2 is independently selected from H, ethylene oxide chains, propylene oxide chains, and ethylene oxide-propylene oxide bock- or random copolymer chains, provided that at least one R.sup.2-group is other than H, the total number of ethylene oxide and propylene oxide per chain is in the range 1-30, and R.sup.3 is a linear or branched alkanediyl chain with 2 to 6 carbon atoms, optionally substituted with —OH; —O—; ═O; —S—; —SO.sub.2—; —Si—; or —P— containing groups.

11. Process according to claim 10 wherein the polymer additive is an alkoxylated glycerol ester having the formula ##STR00010## wherein R.sup.1 is a saturated or unsaturated hydrocarbon chain with 11 to 21 carbon atoms, optionally substituted with —OH; —O—; —(C═O)—O—; —NH—; —Si—; —S—; —P—; —SO.sub.2—; —S═O—; or —SO.sub.3H containing groups, and R.sup.2 is independently selected from H, ethylene oxide chains, propylene oxide chains, and ethylene oxide-propylene oxide bock- or random copolymer chains, provided that at least one R.sup.2-group is other than H, the total number of ethylene oxide and propylene oxide per chain is in the range 1-30, and n is an integer in the range 1-8.

12. Process according to claim 11 wherein the polymer additive is an alkoxylated sorbitan ester have the formula ##STR00011## wherein R.sup.1 is a saturated or unsaturated hydrocarbon chain with 11 to 21 carbon atoms, optionally substituted with —OH; —O—; —(C═O)—O—; —NH—; —Si—; —S—; —P—; —SO.sub.2—; —S═O—; or —SO.sub.3H containing groups, and R.sup.2 is independently selected from H, ethylene oxide chains, propylene oxide chains, and ethylene oxide-propylene oxide bock- or random copolymer chains, provided that at least one R.sup.2-group is other than H, the total number of ethylene oxide and propylene oxide per chain is in the range 1-30.

13. Process according to any one of the preceding claims wherein the masterbatch contains 50-80 wt % of the polymer additive and 20-50 wt % of the thermoplastic polymer.

14. Process according to any one of the preceding claims wherein the mixture of thermoplastic polymer and liquid polymer additive is heated to a temperature in the range 150-250° C.

15. Process according to any one of the preceding claims wherein the thermoplastic polymer is selected from polypropylene, polyethylene, polystyrene, polybutadiene, ethylene-vinyl acetate copolymer, and styrene acrylonitrile.

Description

EXAMPLES

Example 1

[0059] Masterbatches with different additives and polymers were prepared according to the following general procedure. The entire procedure was performed under nitrogen atmosphere.

[0060] The additive was melted. A reactor containing the molten additive and provided with a 6-blade turbine stirrer was heated to 100° C. Solid polymer powder was added while stirring and the resulting mixture was stirred and heated to the temperature indicated in Table 1.

[0061] As soon as the mixture, by visual inspection, was considered to be of a single phase, the reactor was unloaded through a die, thereby creating strands that were subsequently granulated.

[0062] Different additives, polymers, and temperatures were used: see Table 1.

TABLE-US-00001 TABLE 1 Time required for Additive obtaining concentration T single Additive Polymer (%) (° C.) phase Ethoxylated tallow amine HDPE 73-77 225 2.5 (Armostat ® 300) Ethoxylated tallow amine LDPE 48-52 225 2.5 (Armostat ® 300) Ethoxylated tallow amine PP 78-82 195 1.5 (Armostat ® 300) Ethoxylated hydrogenated 73-77 195 1.5 tallow amine (Armostat ® 600) Ethoxylated octadecyl 73-77 195 1.5 amine (Armostat ® 1800) Ethoxylated coco amine 73-77 195 1.5 (Armostat ® 400) Ethoxylated coco amine SAN 48-52 195 1.5 (Armostat ® 400) Ethoxylated coco amine PS 48-52 195 1.5 (Armostat ® 400)

Comparative Example

[0063] Armostat® 300 was melted and pumped into the reactor of Example 1. The reactor was heated to 100° C. Solid polypropylene powder was added while stirring. After 24 hours of stirring, still no homogeneous mixture was obtained. This shows that melting of the polymer is an important and indispensable step in the process of the present invention.

[0064] After heating the contents to 200° C., a homogeneous mixture was obtained.