POLY(VINYL CHLORIDE) MIXTURES FOR WIRE AND CABLE COVERINGS

Abstract

A flame retardant, flexible polyvinyl chloride mixture includes a trio of plasticizers and molybdate-based smoke suppressant for use in wire and cable articles.

Claims

1. A mixture comprising: poly(vinyl chloride); brominated dioctyl phthalate plasticizing the poly(vinyl chloride); polycaprolactone plasticizing the poly(vinyl chloride); linear C.sub.9 trimellitate plasticizing the poly(vinyl chloride); silane surface treated aluminum trihydrate flame retardant; antimony trioxide flame retardant; intumescent char former; molybdate-based smoke suppressant; stearic acid; oxidized polyethylene wax; and calcium/zinc stabilizer; wherein the mixture has both a Limiting Oxygen Index of greater than 50% according to ASTM D2863 and a Plastic Brittleness of less than 0° C. according to ASTM D746 as measured in 2° C. increments.

2. The mixture of claim 1, wherein the mixture has: an unaged Elongation at Break of greater than 100% according to ASTM D638 (Type IV); and a Dynamic Thermal Stability of at least about 90 min according to ASTM 2538.

3. The mixture of claim 1, wherein the mixture has: 100 PHR of poly(vinyl chloride); 10-50 PHR of brominated dioctyl phthalate plasticizing the poly(vinyl chloride); 10-20 PHR of polycaprolactone plasticizing the poly(vinyl chloride); 12-18 PHR of linear C.sub.9 trimellitate plasticizing the poly(vinyl chloride); 75-85 PHR of silane surface treated aluminum trihydrate flame retardant; 1-5 PHR of antimony trioxide flame retardant; 3-7 PHR of intumescent char former; 20-29 PHR of molybdate-based smoke suppressant; 0.05-1 PHR of stearic acid; 0.1-1 PHR of oxidized polyethylene wax; and 3-9 PHR of calcium/zinc stabilizer.

4. The mixture of claim 1, wherein the mixture has: 100 PHR of poly(vinyl chloride); 15-40 PHR of brominated dioctyl phthalate plasticizing the poly(vinyl chloride); 12-18 PHR of polycaprolactone plasticizing the poly(vinyl chloride); 13-17 PHR of linear C.sub.9 trimellitate plasticizing the poly(vinyl chloride); 78-82 PHR of silane surface treated aluminum trihydrate flame retardant; 2-3 PHR of antimony trioxide flame retardant; 4-6 PHR of intumescent char former; 20-27 PHR of molybdate-based smoke suppressant; 0.04-0.5 PHR of stearic acid; 0.3-0.7 PHR of oxidized polyethylene wax; and 5-8 PHR of calcium/zinc stabilizer.

5. A wire or cable covering, comprising the mixture of claim 1.

6. A wire or cable covering, comprising the mixture of claim 2.

7. A wire or cable covering, comprising the mixture of claim 3.

8. A wire or cable covering, comprising the mixture of claim 4.

9. A wire or cable comprising the wire or cable covering of claim 5.

10. The wire or cable of claim 9, wherein the wire or cable is a plenum wire or cable.

11. The wire or cable of claim 9, wherein the wire or cable is a riser wire or cable.

12. The wire or cable of claim 9, wherein the covering is a wire or cable insulation or jacketing.

13. The wire or cable of claim 9, wherein the wire or cable has a transmission core of optical fiber.

14. The wire or cable of claim 9, wherein the wire or cable has a transmission core of metal wire.

15. A method of using plasticized poly(vinyl chloride) in wire or cable covering, comprising: mixing the mixture of claim 1 to form a plasticized polyvinyl chloride; extruding the plasticized polyvinyl chloride around a transmission core of optical fiber or metal wire to form a plenum wire or cable.

16. An industrial curtain, comprising the mixture of claim 1.

17. The mixture of claim 2, wherein the mixture has: 100 PHR of poly(vinyl chloride); 10-50 PHR of brominated dioctyl phthalate plasticizing the poly(vinyl chloride); 10-20 PHR of polycaprolactone plasticizing the poly(vinyl chloride); 12-18 PHR of linear C.sub.9 trimellitate plasticizing the poly(vinyl chloride); 75-85 PHR of silane surface treated aluminum trihydrate flame retardant; 1-5 PHR of antimony trioxide flame retardant; 3-7 PHR of intumescent char former; 20-29 PHR of molybdate-based smoke suppressant; 0.05-1 PHR of stearic acid; 0.1-1 PHR of oxidized polyethylene wax; and 3-9 PHR of calcium/zinc stabilizer.

18. A wire or cable covering, comprising the mixture of claim 17.

19. The mixture of claim 2, wherein the mixture has: 100 PHR of poly(vinyl chloride); 15-40 PHR of brominated dioctyl phthalate plasticizing the poly(vinyl chloride); 12-18 PHR of polycaprolactone plasticizing the poly(vinyl chloride); 13-17 PHR of linear C.sub.9 trimellitate plasticizing the poly(vinyl chloride); 78-82 PHR of silane surface treated aluminum trihydrate flame retardant; 2-3 PHR of antimony trioxide flame retardant; 4-6 PHR of intumescent char former; 20-27 PHR of molybdate-based smoke suppressant; 0.04-0.5 PHR of stearic acid; 0.3-0.7 PHR of oxidized polyethylene wax; and 5-8 PHR of calcium/zinc stabilizer.

20. A wire or cable covering, comprising the mixture of claim 19.

Description

EXAMPLES

[0056] Table 2 shows the sources of ingredients for all Examples and all Comparative Examples. Table 3 shows the processing conditions for making all experimental mixtures. Table 4 shows the molding conditions for testing. Table 5 shows the formulations and test results.

TABLE-US-00002 TABLE 2 Ingredient Brand Name Polyvinyl Chloride SUSPENSION RESIN 240 (OxyVinyls) Chlorinated Polyethylene Plasticizer WEIPREN CPE 2135 (Lianda) Phosphate FR Plasticizer SANTICIZER 2248 (Valtris) Polyvinylidene Fluoride (PVDF) DAIGUARD-770 (Daihachi) Brominated DiOctyl Phthalate Plasticizer DP-45 (Lanxess) Polycaprolactone CAPA 6500 (Perstorp) Thermoplastic Polyester Elastomer HYTREL 3078 (DuPont) Thermoplastic Polyester Elastomer HYTREL 5526 (DuPont) Linear C9 Trimellitate Plasticizer Synplast L9TM-E (PolyOne) Aluminum Trihydroxide with Silane HYMOD (Huber) Surface Treatment Antimony Oxide (Campine) Intumescent Char Former NAFTOCHEM CG-581 (Chemson) Smoke suppressant - Basic Zinc Molybdate Charmax FS-BZMA Complex on Mg(OH)2 (Polymer Additives Group) Smoke suppressant - Basic Zinc Molybdate/ Kemgard HPSS-UF (Huber) Magnesium Hydroxide Complex Smoke suppressant - Molybdate Complex CHARMAX LSZ8A (Polymer Additives Group) Stearic Acid EMERSOL 132 (DeWolf) Oxidized Polyethylene Wax OPE AC-629A (Honeywell) Calcium/Zinc Stabilizer Therm-Chek RC 895P (Valtris)

TABLE-US-00003 TABLE 3 Mixing Instructions #4 Roll Mill/10 L Henschel/Banbury Standard Conditions PVC Resin Initial All Other Ingredients except Polycaprolactone Directly after Resin Polycaprolactone Pellets 140° F. (60° C.) Henschel Drop Temp <155° F. (<68° C.) Cooler Drop Temp 140-150° F. (60-65° C.) Transfer Powder to Banbury Set jacket at 300-310° F. (149-154° C.) & speed to 100 rpm Raise ram twice before dropping fused material ~260° F. & 290° F. (~127° C. & 143° C.) Drop Compoud at 315-335° F. (157-168° C.) (note sucking sound when fused) ~325° F. (~163° C.) Drop Plenum at 340° F. (171° C.) (note sucking sound when fused) # 4 Mill Conditions Compound Initial #4 mill roll set up: Front Back Mill rolls Temps: 350° F. (171° C) 340° F. (163° C) Roll speed: 18 rpm 22 rpm Roll gap: 75-90 mils (1.9-2.3 mm) Mill. for 4 minutes Set gap ~5-10 mils (0.13-0.25 mm) greater than plaque thickness. Remove mill strip and cut samples for testing.

TABLE-US-00004 TABLE 4 Molding Conditions 150 ton Wabash Press Heating Platen Temp - Top (° F.) 360 (182° C.) Heating Platen Temp - Bottom (° F.) 360 (182° C.) Preheat Cycle 30 secs. NA Ramp Cycle 60 secs. 1300 psi (8.9 MPa) Hold Cycle 120 secs. 1300 psi (8.9 MPa) Cooling Cycle 900 secs. 1300 psi (8.9 MPa)

[0057] The objective of the experiments was to identify formulations which satisfied the following two conditions:

[0058] Limiting Oxygen Index of greater 50% according to ASTM D2863; and

[0059] Plastic Brittleness less than 0° C. according to ASTM D746 as measured in 2° C. increments.

[0060] If possible, two other conditions were desired:

[0061] Unaged Elongation at Break of greater than 100% according to ASTM D638 (Type IV); and

[0062] Dynamic Thermal Stability of at least about 30 min. according to ASTM 2538.

TABLE-US-00005 TABLE 5 Comp. Comp. Comp. Comp. Comp. Comp. Comp. Experiments A B C Ex. 1 Ex. 2 Ex. 3 D E F G PVC SUSPENSION RESIN 240 100 100 100 100 100 100 100 100 100 100 WEIPREN 2135 0 0 0 0 0 0 0 0 5 15 Chlorinated Polyethylene SANTICIZER 2248 Plasticizer 10 0 0 0 0 0 0 0 0 0 DAIGUARD-770 PVDF 15 Brominated DiOctyl 15 10 25 25 25 25 25 25 25 25 Phthalate Plasticizer CAPA 6500 15 15 15 15 10 0 10 0 10 0 Polycaprolactone Plasticizer HYTREL 3078 Thermoplastic 0 0 0 0 5 15 0 0 0 0 Polyester Elastomer HYTREL 5526 Thermoplastic 0 0 0 0 0 0 5 15 0 0 Polyester Elastomer Synplast L9TM-E 15 15 15 15 15 15 15 15 15 15 Trimellitate Plasticizer ATH SILANE TR Flame 70 70 80 80 80 80 80 80 80 80 Retardant Antimony Trioxide 2 2 2 2 2 2 2 2 2 2 NAFTOCHEM CG-581 5 5 5 5 5 5 5 5 5 5 Char Former Charmax FS-BZMA Smoke 20 20 20 0 20 20 20 20 20 20 Suppressant Kemgard HPSS-UF Smoke 0 0 0 20 0 0 0 0 0 0 Suppressant CHARMAX LSZ8A Smoke 10 10 0 0 0 0 0 0 0 0 Suppressant Stearic Acid 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 OPE AC-629A Oxidized PE 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Wax Therm-Chek RC 895P 7 7 7 7 7 7 7 7 7 7 Ca/Zn Stabilizer Total 269.6 269.6 269.6 269.6 269.6 269.6 269.6 269.6 269.6 269.6 Testing Results Unaged Properties Specific Gravity (ASTM D792) 1.6143 1.6334 1.6414 1.6924 1.6476 1.6614 * * 1.645 1.6572 Hardness “D”, 47.8 48.2 53 53.4 58 63.8 59.2 66.8 15 s (ASTM D2240) TS @ Break (psi) 1911 1958 1915 2073 2051 1947 2015 2574 (ASTM D638) EL @ Break (%) 244 238 221 236 207 68 212 8 (ASTM D638 (Type IV)) Aged Properties after 10 days @ 100° C. TS @ Break (psi) 1715 1765 1691 1840 1815 2312 1796 2854 (ASTM D638) Retention of TS (%) 90 90 88 89 88 119 89 111 (ASTM D638) EL @ Break (%) 241 211 198 213 162 14 197 0.75 (ASTM D638 (Type IV)) Retention of EL (%) 99 89 90 90 78 21 93 9 (ASTM D638) Aged Properties after 7 days @ 121° C. TS @ Break (psi) 1868 1947 1861 1988 1999 2062 1904 3090 (ASTM D638) Retention of TS (%) 98 99 97 96 97 106 94 120 (ASTM D638) EL @ Break (%) 196 192 202 234 183 21 191 10 (ASTM D638 (Type IV)) Retention of EL (%) 80 81 91 99 88 31 90 125 (ASTM D638) Unaged Properties Brittleness (deg C.) −11 −10 −4 −7 −2 2 1 10 (ASTM D746 as measured in 2° C. increments) LOI (%) (ASTM D2863) 46.6 47.6 51.3 52.3 51.3 51.8 53.6 54.8 Dynamic Thermal Stability 98 26 89 97 101 85 83 49 (Minutes) (ASTM 2538) ASTM E662 Flaming Mode; 209.25 142.88 206.55 220.39 199.21 178.08 240.26 219.95 Ds Max corrected * Unable to be formed into testing plaques.

[0063] Based on the four conditions listed above Table 5, the formulations of Examples 1-3 achieved the goal. Comparative Examples A and B lacked LOI of greater than 50%. Comparative Examples C-G lacked Brittleness of less than 0° C. Only Examples 1-3 achieved both conditions.

[0064] One difference between the Comparative Examples A-G and Examples 1-3 was the amount of molybdate-based smoke suppressant at between 20 and 30 PHR. Depending on progress in the field of molybdate-based smoke suppressants, it is contemplated that as little as 10 PHR can be used in the future. Also, depending on cost considerations, as much as 50 PHR can be used successfully.

[0065] Another distinguishing ingredient was the presence of at least 10 PHR of polycaprolactone plasticizer.

[0066] Another distinguishing ingredient was the presence of at least 30 PHR of aluminum trihydrate.

[0067] Another distinguishing ingredient was the presence of at least 25 PHR brominated dioctyl phthalate plasticizer.

[0068] A distinguishing characteristic of Examples 1-3 is the absence of PVDF from mixtures of the present invention having the goal of replacing PVDF thermoplastic mixtures.

[0069] Another distinguishing characteristic of Examples 1-3 was the absence of phosphate flame retardant plasticizer, even though three other plasticizers are indicated in various amounts.

[0070] Another distinguishing characteristic of Examples 1-3 was the absence of chlorinated polyethylene plasticizer, even though three other plasticizers are indicated in various amounts.

[0071] Though the differences between Comparative Examples A-G and Examples 1-3 were incapable of prediction before experimentation, among the many possible combinations of ingredients, now that the particular combination of ingredients are identified in the inventive mixtures, a person having ordinary skill in the art without undue experimentation can vary the amounts of the ingredients within the acceptable ranges and consider other additives identified above as supplementary properties for wire and cable covering end uses.

[0072] The invention is not limited to the above embodiments. The claims follow.