Polymer composition

Abstract

Polymer composition containing a) a polymer, b) a zeolite, whereby the total amount of the components a) and b) in the composition is higher than 90 wt %, in particular higher than 94 wt %, more preferred higher than 98 wt % and the total amount of water determined by TGA in the temperature range of 25 to 380 C. with a rate of 5 C./min is lower than 15 wt %, based on the amount of residuals obtained after the TGA measurement has been continued to 550 C.

Claims

1. A polymer composition comprising: a) an elastomeric polymer, and b) a zeolite, whereby the total amount of the components a) and b) in the polymer composition is higher than 94 wt %, the total amount of water determined by TGA in the temperature range of 25 to 380 C. with a rate of 5 C./min is lower than 15 wt %, based on the amount of residuals obtained after the TGA measurement has been continued to 550 C., and the amount of the zeolite component b) is 20 to 90 wt %.

2. The composition according to claim 1, wherein the elastomeric polymer a) is selected from the group consisting of natural rubber (NR), polyisoprene rubber (IR), styrene-butadiene rubber (SBR), polychloroprene (CR), polybutadiene rubber (BR), nitrile rubber (NBR), carboxylated nitrile rubber (XNBR), butyl rubber (IIR), brominated isobutylene-isoprene copolymers with bromine contents of 0.1 to 10 wt. % (BIIR), chlorinated isobutylene-isoprene copolymers with chlorine contents of 0.1 to 10 wt. % (CIIR), hydrogenated or partially hydrogenated nitrile rubber (HNBR), styrene-isoprene-butadiene rubber (SIBR), styrene-butadiene-acrylonitrile rubber (SNBR), ethylene propylene diene rubber (EPDM), ethylene propylene copolymer (EPM), ethylene vinyl acetate rubber (EVM), silicone rubber (QM), fluoro elastomer (FKM), ethylene acrylate rubber (AEM), chlorinated polyethylene (CM), and chlorosutfonated rubber (CSM), and a mixture thereof.

3. The composition according to claim 1, further comprising up to a maximum of 10 wt % of a processing aid component c) based on the polymer composition, which processing aid is selected from the group consisting of metal salts of saturated and unsaturated fatty acids, olefinic, paraffinic and other hydrocarbon waxes, hydrocarbon processing oils and vulcanized vegetable oil.

4. The composition according to claim 1, wherein the zeolite component b) has pore openings of approximately 2 to 10 ngstrom.

5. A process for manufacturing an elastomer composition according to claim 1, the process comprising mixing the components a) and b).

6. A process for vulcanization of a rubber composition, the process comprising: mixing the polymer composition according to claim 1 with: i) an elastomeric polymer, ii) a phenol formaldehyde resin cross-linker, and iii) an activator package; wherein at least two or all of the components i), ii), and iii) are individually mixed with the polymer composition, or are premixed prior to mixing with the polymer composition to produce a mixture, optionally shaping the mixture, and vulcanizing the mixture.

7. A polymer composition comprising: a) an elastomeric polymer and b) a zeolite, whereby the total amount of the components a) and b) in the polymer composition is higher than 98 wt %, the total amount of water determined by TGA in the temperature range of 25 to 380 C. with a rate of 5 C./min is lower than 15 wt % based on the amount of residuals obtained after the TGA measurement has been continued to 550 C., and the amount of the zeolite component b) is 25 to 90 wt %.

8. The composition according to claim 7, wherein the zeolites are potassium, sodium and/or calcium forms of zeolite A types having a pore opening of 3 to 5 ngstrom.

9. The composition according to claim 8, wherein the composition comprises: 10 to 65 wt % of the elastomeric polymer; 25 to 90 wt % of the zeolite; and 0 to 2 wt % of a processing aid, based on the polymer composition.

10. The composition according to claim 9, wherein the zeolite has an average particle size of 0.2-50 m, and a moisture content of less than 1.5 wt %.

Description

EXAMPLES

(1) General Procedure

(2) The zeolite/polymer masterbatch compositions of the examples were prepared using an internal mixer with a 3 liter capacity (Shaw K1 Mark IV Intermix) having intermeshing rotor blades and with a starting temperature of 25 C. The zeolite 5A was weighed no more than 10 minutes before mixing of the zeolite/polymer masterbatch. The elastomeric polymer was first introduced to the mixer and allowed to crumble for a period of 30 seconds using a rotor speed of 45 rpm before the addition of the zeolite 5A powder, being an aluminosilicate powder with a particle size of less than 50 m, as supplied with a moisture content of below 1.5 wt %. Maintaining the same rotor speed mixing proceeded until a batch temperature of 140 C. was achieved for the 40 wt % masterbatch, taking a total mixing time of 8 minutes, and 155 C. for the 80 wt % masterbatch, taking a total mixing time of 13 minutes, when the batches were removed from the internal mixer and transferred to a two roll mill (Troester WNU 2) for cooling and forming into 5 mm thick sheets.

(3) A sufficient amount of each of the zeolite/polymer masterbatch compositions was produced to allow repeated mixing of comparative experiments over the test period.

(4) Within 24 hours of producing the zeolite/polymer compositions, both zeolite powder of the same quality as that used to produce the zeolite/polymer masterbatch, and the zeolite/polymer masterbatch were used to produce the initial examples and comparative experiment.

(5) The vulcanizable rubber compositions of examples and comparative experiments were also prepared using an internal mixer with a 3 liter capacity (Shaw K1 Mark IV Intermix) having intermeshing rotor blades and with a starting temperature of 25 C. The elastomeric polymer was first introduced to the mixer and allowed to crumble for a period of 30 seconds using a rotor speed of 45 rpm before the carbon black, mineral oil and zeolite (either as a powder or as a zeolite/polymer masterbatch) were added. Mixing was allowed to proceed until a mix temperature of 70 C. was achieved, when the curing resin and activator were added. Further mixing was allowed to proceed until a mix temperature of 80 C. was achieved, when the rotor speed was reduced sufficiently to allow the mix temperature to be maintained at 80 C. for a period of 1 minute. The PE AC 617 wax and stearic acid were then added, and mixing proceeded for a further minute while the mix temperature was maintained at 80 C. The batches were then transferred to a two roll mill (Troester WNU 2) for cooling, and blending to achieve a high level of ingredient dispersion.

(6) The balance of the zeolite/polymer masterbatch compositions and the zeolite powder not used to prepare the initial examples and comparative experiment were stored next to each other in an exposed state in a non-climate controlled storage area. After 3 months of storage, both the zeolite powder and the zeolite/polymer masterbatch compositions were used to produce new examples and comparative experiments.

(7) The retention of zeolite functionality with respect to its ability to activate a resin cure was determined by comparison of the cure rheology of the examples and comparative experiment. Analysis of cure rheology was carried out using a moving die rheometer (MDR2000E) with test conditions of 20 minutes at 180 C. The cure characteristics are expressed in ML, MH, MH ML, ts2 and tc(90), according to ISO 6502:1999.

(8) The water content, of the masterbatch, can be determined by the following method: The test was carried out on a Mettler-Toledo TGA/DSC-1 Star System machine. 11 mg of sample is taken as received and weighed in the thermo balance of the TGA apparatus. The TGA test procedure starts as described and the weight loss is continuously monitored with time. Heating takes place in an inert atmosphere at a rate of 5 C./min up to 550 C. The amount of the residuals after this treatment is weighted.

(9) Compositions of the zeolite/polymer masterbatches are given in table 1, wherein; IIR MB 40% represents a zeolite/polymer masterbatch containing 40 wt % zeolite mixed into butyl rubber.

(10) IIR MB 80% represents a zeolite/polymer masterbatch containing 80 wt % zeolite mixed into butyl rubber

(11) EPDM MB 40% represents a zeolite/polymer masterbatch containing 40 wt % zeolite mixed into EPDM rubber.

(12) EPDM MB 80% represents a zeolite/polymer masterbatch containing 80 wt % zeolite mixed into EPDM rubber

(13) TABLE-US-00001 TABLE 1 EPDM EPDM IIR MB 40% IIR MB 80% MB 40% MB 80% Lanxess Butyl 301.sup.1) 100 100 Keltan EPDM 2470L.sup.2) 50 50 Keltan EPDM 2650.sup.3) 50 50 Zeolite 5A.sup.4) 67 400 66 400 water content 4.1 8.9 4.3 9.5 wt % (25-380 C.) polymer content 59.7 19.9 59.3 20.2 wt % (25-380 C.) Residual content (wt %) 35.8 70.4 36.1 70.1 Wt % water 10.3 11.2 10.6 11.9 (water/water + residual) .sup.1)LANXESS Butyl 301; isobutylene-isoprene copolymer having a Mooney viscosity ML (1 + 8) at 125 C. of 51 +/ 5, a density of 0.92 g/cm3 and an unsaturation level of 1.85 +/ 0.2 mol %. .sup.2)Keltan 2470L supplied by LANXESS Elastomers: EPDM with a Mooney viscosity ML (1 + 4) at 125 C. of 22, C2 of 69 wt % and ENB unsaturation of 4.2 wt % .sup.3)Keltan 2650 supplied by LANXESS Elastomers: EPDM with a Mooney viscosity ML (1 + 4) at 25 C. of 25, C2 of 53 wt % and ENB unsaturation of 6 wt % .sup.4)water content of the zeolite 5A as starting material was 1.5 wt % and the time from taking such a dry material until the end of the mixing was 18 minutes for the 40 wt % masterbatches and 23 minutes for the 80 wt % masterbatches.

(14) Table 2 shows Comparative Experiment A, which uses zeolite 5A powder having a moisture content of less than 1.5 wt %, and Examples 1, 2, 3 and 4, which use different versions of zeolite/polymer masterbatches. The retained activity of the zeolite used in comparative experiment A, compared with the zeolite/polymer masterbatches used in examples 1, 2, 3 and 4 over a three month period is shown in table 3.

(15) The level of deterioration of the zeolite powder versus the various zeolite/polymer masterbatches with respect to their abilities to increase the activity of a resin cure is expressed as the difference between the rheological data obtained from the original (time zero) Comparative Experiment A and Examples 1, 2, 3 and 4, versus the rheological data obtained from remixed Comparative Experiment A and Examples 1, 2, 3 and 4 after the zeolite powder and zeolite/polymer masterbatches had been stored as described for three months.

(16) It has been clearly shown that the deterioration of important cure characteristics, particularly scorch time (ts2), cure time (tc90) and cross-link density (MH-ML) after three months of storage of all versions of the zeolite/polymer masterbatches (MB) are significantly less than the differences observed from the zeolite power after storage for three month in identical storage conditions.

(17) TABLE-US-00002 TABLE 2 Example/Comparative Comp. Exp. Experiment A Expl. 1 Expl. 2 Expl. 3 Expl. 4 Keltan EPDM 8550.sup.1) 85 85 97.5 85 97.5 Lanxess Butyl 301 15 Carbon Black N550 70 70 70 70 70 Hydrated Magnesium 30 30 30 30 30 Silicate Zeolite 5A.sup.2) 10 IIR MB 40% 25 IIR MB 80% 12.5 EPDM MB 40% 25 EPDM MB 80% 12.5 Paraffinic process Oil.sup.3) 85 85 85 85 85 Curing Resin SP-1045.sup.4) 10 10 10 10 10 SnCl2.2H2O 1.5 1.5 1.5 1.5 1.5 PE AC 617 (PE wax).sup.5) 4 4 4 4 4 Stearic Acid 1 1 1 1 1 Total phr 311.5 311.5 311.5 311.5 311.5 .sup.1)Keltan 8550 supplied by LANXESS Elastomers: EPDM with a Mooney viscosity ML (1 + 4) at 125 C. of 80, C2 of 55 wt % and ENB unsaturation of 5.5 wt % .sup.2)water content of the zeolite 5A (provider Acros Organics) as starting material was 1.5 wt % and the time from taking such a dry material until the end of the mixing with the polymer was 21 minutes .sup.3)Sunpar 2280 from Sun Petroleum Products Co .sup.4)Resin SP-1045 (Provider S.I. Group) .sup.5)Low molecular weight polyethylene supplied by Allied International S.A.

(18) TABLE-US-00003 TABLE 3 Comp. Exp. Rheometer (MDR 2000E) A Expl. 1 Expl. 2 Expl. 3 Expl. 4 Original Results (Time zero) ML [dNm] 1.12 1.18 1.38 1.25 1.51 MH [dNm] 12.19 11.23 13.13 11.53 11.82 MH-ML [dNm] 11.07 10.05 11.75 10.28 10.31 Ts2 [min] 0.25 0.26 0.24 0.25 0.25 Tc90 [min] 4.83 2.71 4.96 2.63 2.93 Results after 3 Months ML [dNm] 0.82 1.14 1.34 1.25 1.43 MH [dNm] 8.55 10.59 12.71 11.9 13.21 MH-ML [dNm] 7.73 9.45 11.37 10.65 11.78 Ts2 [min] 0.56 0.27 0.23 0.24 0.23 Tc90 [min] 8.26 3.00 4.61 2.4 3.06 Results Over test Period ML [dNm] 0.3 0.04 0.04 0.00 0.08 MH [dNm] 3.64 0.64 0.42 +0.37 +1.39 MH-ML [dNm] 3.34 0.6 0.38 +0.37 +1.47 Ts2 [min] +0.31 +0.01 0.01 0.01 0.02 Tc90 [min] +3.43 +0.29 0.35 0.23 +0.13