Silyl functional compound for improving flame retardant properties

Abstract

The invention relates to a composition comprising an organic polymer, and a silyl functional compound comprising a N—Si bond.

Claims

1. A composition comprising: an organic polymer component, and a silyl functional component comprising one or more of the following compounds: ##STR00004## ##STR00005##

2. The composition according to claim 1, wherein the organic polymer component comprises a thermoplastic polymer.

3. The composition according to claim 1, wherein the organic polymer component comprises a thermoset polymer.

4. The composition according to claim 3, wherein the composition additionally comprises: one or more crosslinking components.

5. The composition according to claim 1, wherein the silyl functional component is present in the range of 0.1 to 15.0% by weight, based on the weight of the organic polymer component and the silyl functional component.

6. The composition according to claim 1, wherein a compound of the silyl functional component has a decomposition temperature of at least 140° C.

7. The composition according to claim 1, additionally comprising: at least one other flame retardant different from the silyl functional component.

8. The composition according to claim 7, wherein the at least one other flame retardant includes one or more of an inorganic flame retardant, a brominated flame retardant, a phosphorus based flame retardant, a magnesium flame retardant and a nitrogen based flame retardant.

9. The composition according to claim 8, wherein the at least one other flame retardant includes one or more of aluminum trihydroxide, magnesium dihydroxide, and antimony trioxide.

10. A process of preparing a flame retardant composition, the process comprising: providing an organic polymer component including one or more of a thermoplastic polymer and a thermoset polymer, providing a silyl functional component comprising one or more of the following compounds: ##STR00006## ##STR00007## and mixing the organic polymer component and the silyl functional component.

11. The composition according to claim 1, wherein the organic polymer component includes one or more of thermoplastic polymer and a thermoset polymer.

12. The composition according to claim 1, wherein the silyl functional component is present in the range of 0.1 to 10.0% by weight, based on the weight of the organic polymer component and the silyl functional component.

Description

EXAMPLES

(1) Preparation of Silylamines:

(2) TABLE-US-00001 TABLE 1 Educt Description Phthalimide Supplier: Merk, CAS Nr. 85-41-6 Pyromellitic diimide Supplier: Sigma Aldrich, CAS Nr. 2550-73-4 Maleimide Supplier: Sigma Aldrich, CAS Nr. 541-59-3 Chloro(methyl)diphenylsilane Supplier: ABCR, CAS Nr. 144-79-6 Chloro(dimethyl)phenylsilane Supplier: ABCR, CAS Nr. 768-33-2 tert-Butyldimethylsilyl Supplier: Gelest Inc., CAS Nr. 18162-48-6 chloride Triethylamin Supplier: Sigma Aldrich, CAS Nr. 121-44-8 Tetrahydrofuran Supplier: Sigma Aldrich, CAS Nr. 109-99-9 Dichloromethane Supplier: Sigma Aldrich, CAS Nr. 75-09-02 Perbenzoic acid Supplier: Sigma Aldrich, CAS Nr. 937-14-4 Styrene Supplier: Sigma Aldrich, CAS Nr. 100-42-5 Hydrochloric acid 5% ig Supplier: Sigma Aldrich, CAS Nr. 37262-38-7 Sodium sulfate Supplier: Sigma Aldrich, CAS Nr. 7757-82-6 Hexane Supplier: Sigma Aldrich, CAS Nr. 110-54-3 Methanol Supplier: Sigma Aldrich, CAS Nr. 67-56-1

(3) General Procedure to Prepare Silylamines:

(4) Synthesis of Silylamines A, B, C:

(5) Silylamines A, B, C were prepared using the formulation in table 2.

(6) Xg Educt 1, Xg THF and Xg triethylamine were placed in a 2.0 liter three-necked round bottom flask equipped with mechanical stirrer and drop funnel as well as nitrogen inlet and condenser. The mixture was cooled down to 5-6° C. using ice. Then Xg Educt 2 were added drop wise under nitrogen atmosphere with stirring within 22 min. After the addition was completed Xg of THF were added. The temperature was kept for further 10 min. before it was allowed to raise to 23° C. The stirring was continued under nitrogen atmosphere for further 23 h.

(7) The mixture was filtered and the filter cake was washed with Xg THF. The solvent was removed from the filter cake by distillation using the rotary evaporator at 70° C. and 6.0 mbar.

(8) Preparation of a Polymeric Compound

(9) Synthesis of silylamine D:

(10) 5 g Maleimide, 100 g dichloromethane and 7.25 g triethylamine were placed in a 2.0 liter three-necked round bottom flask equipped with mechanical stirrer and drop funnel as well as nitrogen inlet and condenser. The mixture was cooled down to 0° C. Then 11.5 g Ph.sub.2MeSiCl were added dropwise under nitrogen atmosphere with stirring within 22 min. After addition, the mixture was allowed to warm up to 23° C. and refluxed for 18 h under nitrogen.

(11) The precipitate was removed by filtration. The organic phase was washed twice with 100 mL 5% HCl solution, followed by 100 mL water and 100 mL brine and dried with Na.sub.2SO.sub.4. Solvent was evaporated under vacuum and the solid residue was washed with 100 mL hexane and filtered.

(12) A solution of 5.5 g of the reaction product obtained above and 17 mg perbenzoic acid in 50 g THF was prepared at 23° C. The solution was heated up to 60° C. 17 g of styrene in 25 g THF were added with 1 hour interval. The reaction mixture was stirred overnight at 60° C. After solvent evaporation under vacuum, the polymer was obtained by washing with methanol and filtration. The solid was dried under vacuum.

(13) TABLE-US-00002 TABLE 2 Amount of Amount of Silylamine Educt 1 [g] Educt 1 Educt 2 [g] Educt 2 Comment A 6.65 Phthalimide 6.88 .sup.tBuMe.sub.2SiCl Triethylamine: 4.57 g THF: 58.50 g + 23.40 g + 35.80 g B 4.89 Phthalimide 5.77 PhMe.sub.2SiCl Triethylamine: 3.35 g THF: 57.33 g + 28.66 g + 34.00 g C 11.65 Phthalimide 18.82 Ph.sub.2MeSiCl Triethylamine: 7.99 g THF: 41.02 g + 20.52 g + 36.20 g

(14) TABLE-US-00003 TABLE 3 Decomposition temperature: Silylamine Decomposition temperature A 220° C. B 226° C. C 249° C. D 341° C.

(15) Performance Testing of Silylamines as Flame Retardant Synergists

(16) The following examples show exemplarily the use of the Silylamines as flame retardant synergists in different plastics formulations. The performance of the products is compared to products, which are state of the art.

(17) TABLE-US-00004 TABLE 4 Raw Material Description Moplen HF 501N Supplier: Lyondell Basell, CAS Nr. 9003-07-0 Homo polypropylen MFR 10 g/10 min (230° C./2.16 kg ISO 1133-1) Riblene TR 107 Supplier: Polymeri Europa, Low-density polyethylen Powder Araldite GY 784 Supplier: Huntsmann, Epoxide resin based on Bisphenol A Aradur 43 DB Supplier: Huntsmann, Cycloaliphatic polyamine, curing agent PCO 900 Supplier: Thor, A Flammit PCO 900, organic phosphorus compound containing 24% phosphorus, flame retardant ADK STAB FP-800 Supplier: Adeka, phosphor synergist, high molecular weight, liquid phosphate ester, flame retardant AFLAMMIT PNN 978 Supplier: Thor, Multi-component blend based on ammonium polyphosphate

(18) To show the effectivity of the Silylamines as flame retardant synergists in plastics formulations the components A-D were used in state of the art formulations and the flame retardancy performance was tested.

(19) General Method of Preparation for Testing Silylamines in Polyethylene-Based Formulations:

(20) Thermoplast:

(21) Preparation According to the Formulation in Table 6 and 7.

(22) Thermoplastic polymer powder was mixed with an additional flame retardant synergist. This mixture was fed to a dosing balance of an extruder (model Coperion ZSK 18 K38). The silylamine was fed to a side inlet of the extruder via a second dosing balance. Extrusion was carried out using the temperature profile detailed further below and at 300 rpm. The overall capacity of the extruder was 2 kg/h. The composition left the extruder via a slot die (dimensions 28 mm×3 mm) and was cooled. The extruded strings were granulated to particles having a size in the range of approximately 0.1 to 0.5 mm.

(23) Temperature profiles in the extruder from polymer entry funnel to slot die:

(24) For polypropylene:

(25) 180° C./190° C./195° C./200° C./195° C./190° C./185° C.

(26) For low-density polyethylene:

(27) 145° C./165° C./180° C./190° C./200° C./180° C./180° C.

(28) Preparation of Test Specimens

(29) Test specimen of dimension 125 mm×13 mm×3.2 mm and 125×13 mm×1.6 mm were prepared by injection molding, and subsequently stored at a relative humidity of 45 to 55% and a temperature of 20 to 25° C. for 24 hours.

(30) Thermoset:

(31) Preparation According to the Formulation in Table 8.

(32) Araldite GY 784, silylamine and the additional flame retardant synergist were mixed for 30 sec. Then Aradur 43 DB was added and carefully mixed by hand. Afterwards the system was mixed for 120 sec. at 1.95 m/s with a dissolver (tooth plate, d=40 mm, n=930 rpm).

(33) After mixing the specimen was filled into a mold and stored for 24 h at a temperature of 23° C. and afterwards for 8 h at a temperature of 80° C.

(34) Preparation of Test Specimens

(35) Test specimen of dimension 125 mm×13 mm×3.2 mm and 125×13 mm×1.6 mm were prepared by mill-cut and subsequently stored at a relative humidity of 45 to 55% and a temperature of 20 to 25° C. for 24 hours.

(36) General Procedure to Test Flame Retardancy Properties in Plastics Formulations:

(37) Test Procedure of Flame Retardant Properties

(38) The flame retardant properties of test specimen were determined in a UL-94 fire chamber based on DIN EN 60695-11-10. The test specimen were secured in the sample holders of the UL-94 fire chamber. The burner upper surface was positioned 1 cm below the lower surface of the test specimen, the flame was positioned in a 45° angle and a heating output of 50 W. The test specimen were exposed to the flame for 10 seconds, before removing the flame. If the test specimen extinguished by itself within 10 seconds, the process was repeated until the sample burned or until 5 cycles were performed. For evaluation, the criteria summarized in the table below were used. Test specimen which exhibited fire retardant properties below rating V 2 according to DIN EN 60695-11-10 were marked as F. This rating was added to better distinguish the properties. It is not part of DIN EN 60695-11-10.

(39) TABLE-US-00005 TABLE 5 Rating of fire retardant properties Criteria F V 0 V 1 V 2 Time to extinction of flame of single test specimen >30 s ≤10 s ≤30 s ≤30 s Accumulated time to extinction of flame of >250 s ≤50 s ≤250 s ≤250 s 5 test specimen Time to extinction of flame plus smoldering time >60 s ≤30 s ≤60 s ≤60 s of single test specimen after the second flame cycle Falling droplets or particles yes no no yes Ignition of the cotton underlay by burning particles yes no no yes

(40) The results are summarized in the tables below. The amounts are given in parts by weight (pbw). Comparative Examples are marked with an *.

(41) TABLE-US-00006 TABLE 6 Amount of further Further Amount Amount of flame flame of UL 94 Example Silylamine Silylamine retardant retardant Polymer Polymer classification thickness 1* — — — — 100 Polypropylen F 3.2 mm (Moplen HF 501N) 2* — — 10.0 PCO 900 100 Polypropylen F 3.2 mm (Moplen HF 501N) 3* — — 15.0 PCO 900 100 Polypropylen V2 3.2 mm (Moplen HF 501N) 4* — 15.0 PNN 978 100 Polypropylen F 1.6 mm (Moplen HF 501N) 5* — 10.0 FP 800 100 Polypropylen F 1.6 mm (Moplen HF 501N) 6  1 A 15.0 PCO 900 100 Polypropylen V0 3.2 mm (Moplen HF 501N) 7  1 B 10.0 PCO 900 100 Polypropylen V0 3.2 mm (Moplen HF 501N) 8  1 C 15.0 PCO 900 100 Polypropylen V1 3.2 mm (Moplen HF 501N) 9  2 C 15.0 PNN 978 100 Polypropylen V1 1.6 mm (Moplen HF 501N)

(42) TABLE-US-00007 TABLE 7 Amount of further Further Amount of flame flame Amount of UL 94 Example Silylamine Silylamine retardant retardant Polymer Polymer classification thickness 10* — — — — 100 LDPE F 3.2 mm (Riblene TR 107) 11* — — 15.0 PCO 900 100 LDPE V2 3.2 mm (Riblene TR 107) 12  1 C 15.0 PCO 900 100 LDPE V0 3.2 mm (Riblene TR 107)

(43) TABLE-US-00008 TABLE 8 Amount of further Further Amount of flame flame Amount of UL 94 Example Silylamine Silylamine retardant retardant Polymer Polymer classification thickness 13* — — — — 100 Epoxy F 3.2 mm (Araldite GY 784, Aradur 43 DB) 14* — — 2.5 PCO 900 100 Epoxy(Araldite F 1.6 mm GY 784, Aradur 43 DB) 15* — — 2.5 PCO 900 100 Epoxy V2 3.2 mm (Araldite GY 784, Aradur 43 DB) 16  2 D 2.5 PCO 900 100 Epoxy V0 1.6 mm (Araldite GY 784, Aradur 43 DB) 17  2 D 2.5 PCO 900 100 Epoxy V0 3.2 mm (Araldite GY 784, Aradur 43 DB)

(44) It can be concluded that the addition of silyl-functional compounds comprising a N—Si bond significantly improves the flame retardant properties of the polymer compositions according to the invention.