FLEXIBLE FOAM WITH IMPROVED INSULATION PROPERTIES

Abstract

An expanded polymeric material which consists of at least 200 phr, preferably at least 300 phr, but less than 1000 phr, preferably less than 700 phr ingredients in total, comprising 100 phr of at least one polymer, of which at least one is a sulphur and/or metal oxide crosslinkable elastomer and at least 40 phr, preferably at least 55 phr of at least one polymeric flame retardant, preferably a brominated polymeric flame retardant.

Claims

1. An expanded polymeric material which consists of at least 200 phr, preferably at least 300 phr, but less than 1000 phr, preferably less than 700 phr ingredients in total, comprising a. 100 phr of at least one polymer, of which at least one is a sulphur and/or metal oxide crosslinkable elastomer and b. at least 40 phr, preferably at least 55 phr of at least one polymeric flame retardant, preferably a brominated polymeric flame retardant.

2. The material according to claim 1, wherein the elastomer comprises at least 50 phr of acrylonitrile butadiene rubber (NBR) and/or polychloroprene (CR) and or ethylene propylene diene rubber (EPDM).

3. The material according to claim 1, wherein the 100 phr of polymer comprise at least 80 phr of a blend of at least one thermoplastic, preferably a halogenated thermoplastic and at least one sulphur and/or metal oxide crosslinkable elastomer in a ratio of 3:1 to 1:10 (ratio of thermoplastic to elastomer).

4. The material according to claim 3, wherein the 80 phr of a blend consist of a. acrylonitrile butadiene rubber (NBR) and polyvinyl chloride (PVC, including its copolymers and terpolymers) or b. acrylonitrile butadiene rubber (NBR) and chlorinated polyethylene (CPE) or c. polychloroprene (CR) and chlorinated polyethylene (CPE) or d. ethylene propylene diene rubber (EPDM) and chlorinated polyethylene (CPE).

5. The material according to claim 1, wherein the thermal conductivity ( value) is 0.031 W/m*K @ 0 C., preferably 0.030 W/m*K at 0 C. according to DIN EN ISO 8497/DIN EN 12667.

6. The material according to claim 1, wherein the brominated, polymeric flame retardant has a bromine content of at least 50 wt %, preferably at least 60 wt %, especially preferred at least 70 wt %.

7. The material according to claim 1, wherein the brominated polymeric flame retardant has an aromatic structure, preferred is brominated polyphenyl ether.

8. The material according to claim 1, wherein the share of polymer and polymeric flame retardantrelated to the overall quantity of all ingredientssums up to 20 wt %, preferably 30 wt %.

9. The material according to claim 1, comprising at least 60 phr, preferably at least 100 phr, especially preferred at least 150 phr of at least one inorganic filler.

10. The material according to claim 1, comprising at least one plasticizer which is present in the formulation in at least 15 phr, preferably at least 25 phr, especially preferred at least 35 phr.

11. The material according to claim 1, which is crosslinked by at least one sulphur and/or metal oxide crosslinking system.

12. The material according to claim 1, comprising at least one synergist for the polymeric flame retardants, preferably antimony (Sb) and/or zinc (Zn) based materials, especially preferred are antimony trioxide and/or zinc stannate.

13. The material according to claim 1, which is expanded to a density of <60 kg/m.sup.3, preferably <55 kg/m.sup.3, especially preferred <50 kg/m.sup.3 according to DIN EN ISO 845.

14. The material according to claim 1, which has a closed cell structure of <5.0%, preferably <2.5% determined by a vacuum water absorption according to ASTM D 1056.

15. The material according to claim 1, which is classified as Class A flame retardant according to ASTM E84/CAN ULC S 102 and/or classified as C.sub.L-s3,d0/C-s3, d0, preferably B.sub.L-s3,d0/B-s3,d0, especially preferred B.sub.L-52,d0 according to EN ISO 13823.

16. A process for manufacturing the material according to claim 1, wherein the polymeric material is expanded by decomposition of a chemical blowing agent, preferably of nitroso type, azo type and/or aromatic hydrazide type, especially preferred is azodicarbonamide.

17. The use of the material according to claim 1 for thermal and/or acoustic insulation.

Description

EXAMPLES

[0049] The following examples according to the present invention and comparative examples were manufactured in a three step process: first of all mixing of the compound, afterwards extrusion (shaping) and finally expansion and crosslinking.

[0050] The compounds were mixed in an internal mixer with an average mixing time of 10 minutes and an average dumping temperature of 145 C. for compounds comprising PVC and 120 C. for compounds without PVC. The compounds were further homogenized on a roller mill and the crosslinking system and azodicarbonamide as blowing (expansion) agent were added during such step.

[0051] Extrusion was performed on a strip feeded single screw vacuum extruder providing unexpanded sheets and tubes. Those were crosslinked and expanded simultaneously in a hot air oven cascade of five ovens to sheets of 25 mm wall thickness and tubes of 25 mm wall thickness and 22 mm inner diameter. Table 1 lists the raw materials used for the compounds. Table 2 gives an overview about the recipes of the evaluated compounds and Tables 3 and 4 comprise the technical properties of the foamed and crosslinked material.

TABLE-US-00001 TABLE 1 Raw materials Chemical Name Trade Name Supplier Polychloroprene (CR) Neoprene WM-1 DuPont, USA Acrylonitrile butadiene rubber (NBR) Europrene N 2860 Polimeri Europe, Italy Butadiene rubber (BR) Buna CB 24 F Lanxess, Germany Polyvinyl chloride (PVC) Vinnolit S3265 Vinnolit, Germany Vinyl chloride vinyl acetate copolymer Kanevinyl MB1008 Kaneka Corporation, Japan (PVC/VA) Chlorinated Polyethylene (CPE) Elaslen 401AY Showa Denko, Japan Chloroparaffin (CP1) Cereclor 46 Ineos Chlor Ltd., Switzerland Chloroparaffin (CP2) Hordaflex LC 70 Leuna Tenside GmbH, Germany Diphenyl-2-ethylhexyl phosphate (DPO) Disflamoll DPO Lanxess, Germany Carbon black (CB) Corax N550 Evonik Industries, Germany Aluminium hydroxide (ATH) AluMill F280 Europe Minerals, Netherlands Huntite/hydromagnesite mixture (HH) Securoc C10 Ankerport, Netherlands Antimony trioxide (ATX) Triox Produits Chimiques de Lucette, France Azodicarbonamide (ADC) Unicell D 300 K Tramaco, Germany Decabromodiphenyl ether (Deca-BDE) Saytex 102 E Albemarle, France Brominated polyphenyl ether (BPPE) Emerald Innovation 1000 Great Lakes, USA Tribromophenol end-capped F-3014 ICL Industrial Products, Israel brominated epoxy (ECBE)

TABLE-US-00002 TABLE 2 Comparative and innovative polymeric material 1* 2* 3* 4 5 6 7 8 Acrylonitrile butadiene rubber 60.0 60.0 60.0 60.0 60.0 (NBR) Polychloroprene (CR) 70.0 70.0 70.0 Butadiene rubber (BR) 5.0 10.0 5.0 5.0 5.0 5.0 10.0 10.0 Polyvinyl chloride (PVC) 15.0 15.0 15.0 15.0 15.0 Vinyl chloride vinyl acetate 20.0 20.0 20.0 20.0 20.0 copolymer (PVC/VA) Chlorinated Polyethylene (CPE) 20.0 20.0 20.0 Chloroparaffin (CP1) 60.0 5.0 60.0 60.0 60.0 60.0 5.0 5.0 Chloroparaffin (CP2) 80.0 30.0 5.0 Diphenyl-2-ethylhexyl 5.0 5.0 5.0 5.0 5.0 phosphate (DPO) Carbon black (CB) 10.0 1.0 10.0 10.0 10.0 10.0 1.0 1.0 Aluminium hydroxide (ATH) 60.0 220.0 60.0 60.0 60.0 60.0 220.0 220.0 Huntite/hydromagnesite 40.0 40.0 40.0 40.0 40.0 mixture (HH) Antimony trioxide (ATX) 7.0 3.0 7.0 7.0 7.0 7.0 3.0 3.0 Azodicarbonamide (ADC) 48.0 50.0 48.0 48.0 48.0 48.0 50.0 50.0 Decabromodiphenyl ether 63.0 38.0 18.0 18.0 (Deca-BDE) Brominated polyphenyl ether 25.0 45.0 63.0 50.0 75.0 (BPPE) Tribromophenol end-capped 45.0 brominated epoxy (ECBE) Additives, crosslinking agents, 30.0 28.0 30.0 30.0 30.0 30.0 28.0 28.0 etc. (AD) 423.0 487.0 423.0 423.0 423.0 423.0 487.0 487.0 *= comparative examples

[0052] Table 3 presents the density (according to DIN EN ISO 845), thermal conductivity at 0 C. (according to DIN EN ISO 8497/DIN EN 12667) and water vapour transmission (WVT, according to EN 13469/EN 12086).

[0053] It clearly points out that polymeric flame retardants have a significant impact on thermal conductivity of crosslinked and expanded insulation foams. Additionally, it also increases the WVT value, means decreases water vapour transmission through the material.

TABLE-US-00003 TABLE 3 Technical properties Density Thermal conductivity Material [kg/m.sup.3] [W/(m*K)] @ 0 C. WVT 1* 48 0.0325 11300 2* 58 0.0352 8400 3* 49 0.0328 11200 4 48 0.0302 12500 5 50 0.0309 11300 6 48 0.0291 13100 7 52 0.0309 9100 8 49 0.0298 10300 *= comparative examples

[0054] Table 4 shows that also the burning behaviour is not impacted in a negative way if a sufficient amount of polymeric, brominated flame retardant is used. The smoke development can rather be decreased when substituted against conventional, brominated flame retardants like decabromodiphenyl ether.

TABLE-US-00004 TABLE 4 Flammability test results SBI (EN 13823) ASTM E 84 Material sheets tubes sheets 1* B-s3, d0 B.sub.L-s3, d0 10/300 2* B-s2, d0 B.sub.L-s1, d0 10/25 3* B-s3, d0 B.sub.L-s3, d0 15/300 4 B-s3, d0 B.sub.L-s3, d0 15/130 5 B-s3, d0 B.sub.L-s3, d0 15/200 6 B-s3, d0 B.sub.L-s2, d0 10/70 7 B-s2, d0 B.sub.L-s2, d0 15/30 8 B-s2, d0 B.sub.L-s1, d0 20/40 *= comparative examples