Flame-proofed polymer composition

Abstract

A flame-proof vulcanized polymer composition includes as a polymer component a halogen-free olefinic M-group elastomer with a saturated main chain at an amount of greater than 50 Parts per Hundred Rubber (phr) with respect to polymer components, a halogen-free water-releasing flame retardant or a combination of different halogen-free water-releasing flame retardants at an amount of in total 30 to 130 phr and a mineral oil plasticizer having an amount of less than or equal to 50 phr. Further disclosed are a method for producing the flame retardant vulcanized polymer composition, a flame-retardant article and an elastic flame-proof composite element.

Claims

1. A flame retardant, vulcanised polymer composition, comprising: at least one halogen-free olefinic M-group elastomer as a polymer component with a saturated main chain at an amount of greater than 70 phr with respect to polymer components; wherein the at least one of the polymer component is single-phase and homogenous; at least one halogen-free water-releasing metal hydrate or a combination of different halogen-free water-releasing metal hydrates as flame retardant at an amount of in total 60 to less than 100 phr; and a mineral oil plasticiser in an amount of less than or equal to 50 phr; wherein a vulcanized matrix is formed by a sulphur or a sulphur-containing cross-linking system such that the cross-linking system extends over the entire matrix and is completely interspersed through the matrix; and wherein the entire composition is halogen-free.

2. The composition of claim 1, wherein the mineral oil plasticiser is in a maximum amount of less than or equal to 20 phr, or the composition is free of mineral oil plasticisers.

3. The composition of claim 1, wherein halogen-free olefinic elastomers are included at an amount of 100 phr as the only polymer components.

4. The composition of claim 1, wherein the water-releasing flame retardant includes magnesium hydroxide (MDH) or aluminium hydroxide (ATH), or a mixture thereof, and the water-releasing flame retardant is solid, in a powder or in a crystalline form.

5. The composition of claim 1, wherein the olefinic elastomer comprises a homopolymer or a copolymer or a terpolymer, with diene monomer units, and a diene-containing termonomer, wherein the termonomer is present in an amount of at least 0 wt. % to 12 wt. % with respect to the olefinic elastomer.

6. The composition of claim 1, wherein the olefinic elastomer is selected from the group consisting of ethylene propylene diene rubber (EPDM) and ethylene propylene rubber (EPM), and the composition includes ethylene propylene diene rubber (EPDM) and/or ethylene propylene rubber (EPM) as individual polymer components.

7. The composition of claim 1, wherein the olefinic elastomer is a rubber having an unsaturated side group, which is an ethylene propylene diene rubber (EPDM), which includes non-conjugated, diene monomer units, selected from the group consisting of 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-cyclopentadiene, dicyclopentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,4-hexadiene, 1,4-cyclohexadiene, tetrahydroindene, methyl tetrahydroindene, ethylidene norbornene and/or 5-ethylidene-2-norbornene (ENB), 5-methylene-2-norbornene (MNB), 1,6 octadiene, 5-methyl-1,4hexadiene, 3,7-dimethyl-1,6-octadiene, 5-iso-propylidene-2-norbornene, 5-vinyl-2-norbornene (VNB), wherein the ethylene propylene diene rubber (EPDM) is a terpolymer from ethylene, propylene and 5-ethylidene-2-norbornene (ENB) or dicyclopentadiene (DCPD).

8. The composition of claim 1, further comprising at least one further polymer component which is an R-group or Q-group silicone elastomer or a thermoplastic polymer, said polymer components of the composition being present as a homogeneous polymer mixture or a blend.

9. The composition of claim 8, wherein the at least one further polymer component is a vinyl-acetate-containing thermoplastic polymer, in particular a homopolymer, copolymer or terpolymer of vinyl acetate selected from the group consisting of polyvinyl acetate (PVAc) and ethylene vinyl acetate (EVA).

10. The composition of claim 9, wherein the vinyl-acetate-containing thermoplastic polymer has a melting temperature or a beginning of a melting region of less than 150 C., and the vinyl-acetate-containing thermoplastic polymer includes a vinyl acetate fraction of 40 to 75 wt. %, optionally, an uncross-linked, vinyl-acetate-containing polymer in an amount from 0 to 50 phr.

11. The composition of claim 8, further comprising ethylene propylene diene rubber (EPDM) or ethylene propylene rubber (EPM) or ethylene propylene diene rubber (EPDM) and ethylene vinyl acetate (EVA) as a homogeneous polymer mixture, or ethylene propylene rubber (EPM) and ethylene vinyl acetate (EVA) as a homogeneous polymer mixture, or ethylene propylene diene rubber (EPDM) and polyvinyl acetate (PVAc) as a homogeneous polymer mixture, or ethylene propylene rubber (EPM) and polyvinyl acetate (PVAc) as a homogeneous polymer mixture.

12. The composition of claim 8, wherein the polymer mixture is formed as an interpenetrating mixture from chains of the vinyl-acetate-containing polymers and the polymer mixture has sulphur cross-links, elastomer chains, and the polymer components are present as chemical, wide-mesh, cross-linked, spatial network molecules.

13. The composition of claim 1, wherein the polymer component or the polymer components of the composition are present together as in a substantially single-phase and homogeneous mixture-without a macroscopic and a microscopically visible phase separation, and the polymer components or the polymer mixture are free of dispersed vulcanised particles of elastomers or rubber domains with an average diameter greater than 0.5 m.

14. The composition of claim 1, wherein the composition at a temperature of 150 to 200 C., has exclusively elastomer properties and has no thermoplastic properties, such that the composition is not formed as an olefin-based thermoplastic elastomer (TPE-0) or as a cross-linked olefin-based thermoplastic elastomer (TPE-V).

15. The composition of claim 1, wherein the composition has no melting peak as measured by dynamic differential scanning calorimetry at a temperature up to 200 C.

16. The composition of claim 1, wherein the composition has a loss factor of tan <0.3 in a temperature range from room temperature to approximately 200 C., said loss factor being a ratio of loss to storage modulus under dynamic shear stress.

17. The composition of claim 1, produced or obtained by producing the polymer component or by mixing the polymer components into a homogeneous blend, with the composition not being cross-linked and/or vulcanised and subsequent incorporation of a cross-linking agent, a flame retardant, additives and/or process materials, at a maximum temperature of 110 C., said composition shaped and vulcanised without shear stress, at an elevated temperature, optionally under pressure.

18. The composition of claim 17, obtained by static vulcanisation while avoiding shear stress and/or avoiding dynamic vulcanisation, after successful shaping.

19. The composition of claim 1, wherein the polymer components, of the entire composition, are halogen-free.

20. The composition of claim 1, further comprising: an ethylene propylene diene rubber (EPDM) or ethylene propylene rubber (EPM) at an amount of 70-100 phr; a vinyl-acetate-containing polymer, which is ethylene vinyl acetate (EVA) at an amount of 0-30 phr; a mineral oil plasticiser at an amount of 0-10 phr; a flame retardant, which is aluminium hydroxide (ATH) at an amount of 60 to less than 100 phr; carbon black at an amount of 0-80 phr; and the remainder being process materials and additives.

21. The composition of claim 1, wherein the composition has a hardness of 40 to 90 Shore A, a tensile strength >5 MPa, a wear volume <400 mm.sup.3, a density <1.4 g/cm.sup.3, and a MARHE value (ISO 5660-1) <90 kW/m.sup.2, and complies with standard EN 45545-2.

22. A method for producing a flame retardant, vulcanised polymer composition according to claim 1, comprising: first mixing together polymer component(s) with cross-linking agent(s), and flame retardant(s), and optionally, additives and process materials, in an absence of cross-linking and/or vulcanisation of the components so as to form a homogeneous mixture; then shaping the polymer composition; and then vulcanizing the polymer composition at a point in time selected from the group consisting of beginning of shaping, during the shaping, at the end of the shaping and after completed shaping as a static, non-dynamic vulcanisation, thereby avoiding creating shear stress.

23. The method of claim 22, wherein the mixing to form the mixture is carried out before the shaping at a temperature of at most 125 C. and for a time not critical for premature vulcanisation, wherein the mixture and/or polymer component(s) are present in a softened state during the mixing.

24. The method of claim 22, wherein the shaping is carried out at a temperature in a range from 70 C. to 100 C. and for a time not critical for premature vulcanisation.

25. The method of claim 22, wherein the vulcanising takes place at a temperature of at most 240 C., at an elevated pressure of 100 to 200 bar with respect to the mixing and/or the shaping.

26. A flame-retardant article, comprising a composition according to claim 1.

27. The article of claim 26, used as a spring element, a damping element, a seal, a hose, a mat, a moulded part, a protective clothing, or as an elastomer profile for windows or as a component thereof.

28. A composition, comprising: a halogen-free olefinic M-group elastomer as a polymer component with a saturated main chain at an amount of greater than 50 phr with respect to polymer components; a halogen-free water-releasing flame retardant or a combination of different halogen-free water-releasing flame retardants at an amount of in total 30 to less than 100 phr; and a mineral oil plasticiser having an amount of less than or equal to 50 phr, wherein the composition is formed into a matrix by a sulphur or a sulphur-containing cross-linking system such that the cross-linking system extends over the entire vulcanised matrix and is completely interspersed through the matrix.

29. The composition of claim 28, used as a spring element, a damping element, a seal, a hose, a mat, a moulded part, a protective clothing, or as an elastomer profile for windows or as a component thereof.

30. The composition of claim 28, wherein the flame retardant is zinc borate.

31. An elastic flame-proof composite element, suitable for damping oscillations and for suspension, comprising: a base body made from rubber and provided with a coating of a composition including a halogen-free olefinic M-group elastomer as a polymer component with a saturated main chain at an amount of greater than 50 phr with respect to polymer components, a halogen-free water-releasing flame retardant or a combination of different halogen-free water-releasing flame retardants at an amount of in total 30 to less than 100 phr and a mineral oil plasticiser having an amount of less than or equal to 50 phr, wherein a vulcanised matrix on a mixture matrix is formed by a sulphur or a sulphur-containing cross-linking system which extends over the entire vulcanised matrix and is completely interspersed through the matrix, said composition coating the base body at least partially or in sections, on an outer surface thereof, optionally, over the entire outer surface thereof.

32. The composite element of claim 31, used as a spring element, a damping element, a seal, a hose, a mat, a moulded part, a protective clothing, or as an elastomer profile for windows or as a component thereof.

Description

EXAMPLE 1

(1) EPDM mixture without vinyl-acetate-containing polymer

(2) Cross-linking: Sulfur:

(3) Hardness: approx. 50 80 Shore A

(4) Recipe data in phr

(5) TABLE-US-00001 Mixture number 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Hardness, Shore A 56 52 55 58 60 63 72 80 EPDM (Ethylene: 55 wt. %, ENB: 6.5 wt. %) 100 100 100 100 100 100 100 100 Paraffinic mineral oil with C.sub.aromatic: 2% 55 50 40 25 18 12 5 0 Carbon black Durex O/35 (Iodine Absorption 15 15 15 15 27 40 50 60 Number: 30 mg/g; ASTM D 1510) Al(OH).sub.3 with d.sub.50 = 1 m 160 80 70 60 60 60 60 60 Zinc borate d.sub.50 = 2.1 m 10 Zinc oxide, BET = 4.5 m.sup.2/g 5 5 5 5 5 5 5 5 Ground sulfur 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Deovulc BG 187 (accelerator mixture) 5 5 5 5 5 5 5 5 Stearic acids 1 1 1 1 1 1 1 1 Silicic acid/kaolinite mixture with d.sub.50 < 2.4 m 15 15 15 15 15 15 15 15 Hardness, Shore A 56 52 55 58 60 63 72 80 Fire test 1 Burner test Extinguishing time, s 50-100 >100 >100 50-100 40 <6 <5 <3 Assessment Weakly Moderately Moderately Weakly Self- Self- Self- Self- after- after- after- after- extin- extin- extin- extin- burning burning burning burning guishing guishing guishing guishing Fire test 2 EN 45545-2, R9 Smoke gas density (ISO 5669-2): D.sub.Smax 105 90 85 71 58 57 <60 <60 Smoke gas toxicity (ISO 5669- 2): CIT.sub.G 0.04 0.02 0.02 0.02 0.02 0.02 0.018 0.015 Heat release rate (ISO 5660-1): MARHE (kW/m.sup.2) >90 80 77 65 58 57 54 50 Not met R9/HL2 R9/HL2 R9/HL2 R9/HL3 R9/HL3 R9/HL3 R9/HL3 Hardness, Shore A 56 53 55 56 60 63 72 80 Density, g/cm.sup.3 1.42 1.22 1.22 1.23 1.24 1.25 1.27 1.29 Elasticity, % 39 53 53 53 49 46 42 36 Notch toughness, N/mm 6.2 7.2 7.3 7.6 8.4 9.8 12.8 14.1 Tensile strength, MPa 4.7 6.9 7.2 7.3 7.5 7.8 7.9 8.1 Elong. at break % 481 510 500 480 420 390 340 310 Wear volume, mm.sup.3 620 290 294 297 291 285 270 261

(6) Among other things, it can be seen here that the standards for fire protection are already fulfilled at less than 50 phr mineral oil, and simultaneously the mechanical and dynamic values are advantageous.

EXAMPLE 2

(7) EPDM mixture without vinyl-acetate-containing polymer

(8) Hardness: 80 Shore A

(9) Cross-linking: Peroxide

(10) Reference: Mixture 2.1 not flame-proofed

(11) Recipe data in phr

(12) TABLE-US-00002 Mixture 2.1 2.2 2.3 2.4 EPDM (Ethylene content: 100 100 100 100 48 wt. %, ENB: 7.8 wt. %) Carbon black N 550 60 60 60 50 Paraffinic mineral oil 0 20 10 0 with C.sub.aromatic: 2% Al(OH).sub.3 with d.sub.50 = 1 gm 0 100 100 50 Di-(2-tert-butyl- 6 6 6 6 peroxyisopropyl)-benzene Trimethylolpropane 1 1 1 1 trimethacrylate Silicic acid/kaolinite mix- 10 20 20 10 ture with d.sub.50 < 2.4 m Fire test 1 Burner test Extinguishing time, s >100 50- 15 <3 100 Assessment Not self- Weakly Self- Self- extin- after- extin- extin- guishing, burning guishing guishing burns in- creasingly Hardness, Shore A 80 75 81 80 Density, g/cm.sup.3 1.10 1.34 1.36 1.25 Elasticity, % 56 45 52 48 Notch toughness, N/mm 12 10 10.2 10.5 Tensile strength, N/mm.sup.2 12.7 8.1 9.4 10.4 Elong. at break % 155 217 167 190

EXAMPLE 3

(13) EPDM mixture with vinyl-acetate-containing polymer

(14) Cross-linking: Peroxide

(15) Hardness: 75-80 Shore A

(16) Recipe data in phr

(17) TABLE-US-00003 Mixture 3.1 3.2 3.3 EPDM (Ethylene content; 52 wt. %, 90 90 80 ENB: 7.5 wt. %) EVA with 60 wt. % VAC 10 10 20 Carbon black N 550 50 50 50 Paraffinic mineral oil with C.sub.aromatic: 2% 20 10 10 Mg(OH).sub.2, d.sub.50 = 0.9 m 110 90 90 Zinc borate d.sub.50 = 2.1 m 10 10 10 Di-(2-tert-butyl-peroxyisopropyl)- 7 7 7 benzene Trimethylolpropane trimethacrylate 1 1 1 Silicic acid/kaolinite mixture 15 15 15 with d.sub.50 < 2.4 Fire test 1 Burner test Extinguishing time, s 15 10 spontaneous Assessment Self- Self- Self- Hardness, Shore A 77 78 78 Density, g/cm.sup.3 1.32 1.31 1.31 Elasticity, % 47 46 42 Notch toughness, N/mm 10.1 12.2 11.8 Tensile strength, N/mm.sup.2 9.3 9.5 9.6 Elong. at break % 189 205 210

(18) In examples 2 and 3, the effects of the mineral oil content and the flame retardant content can be seen

EXAMPLE 4

(19) EPDM with butyl rubber (IIR) (R-type elastomer)

(20) Hardness: 46 Shore A

(21) Cross-linking: Sulfur:

(22) Recipe data in phr

(23) TABLE-US-00004 Mixture number 4.0 Hardness, Shore A 46 EPDM (Ethylene: 55 wt. %, ENB: 6.5 70 IIR (ML 1 + 8, 125 C.: 51, unsaturated 30 fraction: 1.7 mol % Paraffinic mineral oil with C.sub.aromatic: 2% 30 Carbon black N 550 10 Al(OH).sub.3 with d.sub.50 = 1 m 80 Silicic acid/kaolinite mixture with d.sub.50< 10 Zinc oxide, BET = 4.5 m.sup.2/g 5 Stearic acids 1 Deovulc BG 187 (accelerator mixture) 6 Ground sulfur 2.0 Fire test 1 Burner test Extinguishing time, s 50-100 Assessment Weakly Mixture 4 Hardness, Shore A 46 Density, g/cm.sup.3 1.22 Tensile strength, N/mm.sup.2 9.6 Elong. at break % 760

(24) The burner test was carried out with the following set-up:

(25) The distance from the Bunsen burner to the sample was 140 mm. The sample body had a diameter of 42 mm with a thickness of 6 mm. It was flamed for 45 seconds. After the end of flaming, the afterburning behaviour was observed and the time till self-extinguishing was measured.

(26) The fire test according to EN 45545-2 was carried out according to the defined standards.

(27) The production of the example recipes was carried out either on a rolling mill or in an internal mixer:

(28) When working on the rolling mill, the following sequence was employed: EPM/EPDM and if appropriate EVA were mixed together until a smooth rolled sheet was obtained. No roll cooling was employed in this case. In order to ensure homogeneity, before adding the additives the mixture sheet was alternately notched three times from the left and right to approximately of the roll width at an angle of approximately 45 and the thus detached mixture was applied again on the other side, referred to below as 3 left and right notching. Before beginning the admixing process of the other mixture components, the water cooling of the rolls is switched on. The addition of the solid and liquid additives proceeds in small amounts, with continuous gap adjustment. Once the rubber has absorbed all the substances, it is uniformly notched three times from the left and right in turn. The rolled sheet is removed from the roll and stored for 10 minutes at room temperature in order to allow cooling of the mixture and the roll. The accelerator is then added together with the sulfur. Once the mixture has absorbed the accelerator and sulfur, it is again notched three times from the left and right. Finally, the completed mixture is removed completely from the rolls and inverted six times. Alternatively, the rolled sheet is fed out, in and transverse to the roll direction. The rolled sheet is then removed in the desired sheet thickness.

(29) When working with the internal mixer, the following sequence was employed:

(30) Before beginning the mixing process, the mixing chamber was temperature controlled at 50 C.+/5 C. First EPM/EPDM and if necessary EVA were filled and kneaded for 120 seconds with a lowered die. The solid and liquid additives were then added. The die was lowered and the mixture kneaded for a further 120 seconds. The die is then cleaned and the mixture is mixed for a further maximum of 60 seconds or until obtaining a mass temperature of 100 C. in the mixing chamber and then discharged. Mixture cooling and homogenisation takes place on the subsequent rolling mill by means of a stock blender. The coolant water temperature at the inlet has a maximum temperature of 30 C. The accelerator is added when the mixture has attained a temperature of approximately 80 C.+/5 C. After further homogenising with the stock blender (5 cycles), the mixture sheet is taken from the roll and taken on a transport carriage for further processing.

(31) The example recipes were prepared in an LH 50 A internal mixer (built in 1961), according to the above methods with a rotary speed of the tangential blades of 30 rpm. After discharging the mixture at 100 C., the mixture is cooled on a roller mill (Berstorff 1500 mm), as described above, and the accelerator mixed in. Mixture sheets having a thickness of 4 mm are taken from the roll and stored on a transport carriage until further processing.

(32) The vulcanisation of the mixture in example 1 is carried out in a press at 160 C. for 30 minutes and at a pressure of 200 bar, however in each case after successful shaping and avoiding any shear stress; the vulcanisation of the mixture of examples 2 and 3 was carried out 180 C. for 10 minutes under otherwise identical conditions. Alternatively, the vulcanisation can also be carried out without pressure or at normal pressure, but in each case at elevated temperature, e.g. by continuous vulcanisation in the salt bath for profiles.

(33) The thus obtained composition can undergo shaping and is subsequently vulcanised and used directly in this form, without further processing steps, as a flame-proofed article, for example as a profile. Alternatively, the resulting composition can also be further processed into a composite element and only be vulcanised after the end product has been produced.