IL111932A - Flame retardant polymer compositions based on tris trinol cyanurate (ttc) - Google Patents

Description

REF : 315.3/94 FLAME RETARDANT POLYMER COMPOSITIONS BASED ON TRIS TRINOL CYANURATE (TTC) 3153/94 -1- FLAME RETARDANT POLYMER COMPOSITIONS BASED ON TRIS TRINOL CYANURATE ( TC) Field of the Invention The present invention relates to thermoplastic flame-retarded polymeric compositions with improved properties. More particularly, the invention relates to the use of mono- or di- or tris Trinol Cyanurate (collectively referred to as "Trinol Cyanurates") as a flame-retardant for polymers, copolymers and polymer blends such as polystyrene, impact-resistant polystyrene, polystyrene foam, ABS resin, polypropylene, polyethylene, polyurethane, thermoplastic polyester, unsaturated polyester, polymethyl methacrylate, styrene acrylonitrile copolymer, polypropylene copolymer, and PVC elastomers.

Background of the Invention Trinol Cyanurate have the general formula: wherein n=l, 2 or 3; m= 3-n, and R= CI, Br, NH2, OH or an organic radical. 3153/94 -2- A particular useful compound is Tris Trinol Cyanurate (TTC).

Tris trinol cyanurate is l,3,5-triazine-2,4,6-tris[3-bromo-2,2-bis(bromomethyl)propoxy)]. It has been used in the art as a flame-retardant (FR) for impregnating natural and synthetic materials, as described in US 4,113,902. The procedure comprises treating said materials with an aqueous dispersion of a brominated aliphatic compound (e.g., TTC). In the process, said brominated compound is in solid form at room temperature, substantially insoluble in water and reduced to a fine particle size, in the same bath with an emulsion of a suitable adhesive polymeric binder, followed by drying and baking. iim ifl y of the Invention It is an object of the present invention to provide flame-retarded polymeric compositions comprising tris trinol cyanurate (TTC), characterized by improved thermal mechanical characteristics and stability to UV radiation in comparison with conventional FR agents.

The flame-retarded polymeric composition according to the invention comprises a flame-retardant effective amount of a Trinol Cyanurate, alone or together with other FR agent(s). An illustrative (but non-limitative) composition comprises: 3153/94 -3- - TTC - 0.5-25% - Other bromine-containing organic FRs - 0-25% - Antimony oxide - 0-15% - Phosphorus-containing FRs - 0-20% - conventional plastic additives.

The process for the preparation of TTC comprises reacting cyanuric halide with trinol [0(ΟΉ.9 τ)ΛϋΗ.9ΡΉ], in the presence of a proton scavenger, such as an organic base or tertiary amine, and metals like zinc powder that react with hydrogen that is formed in the reaction, to promote the reaction and to prevent side reactions in an organic solvent. Preferably, the organic solvent is a halogenated solvent. Other Trinol Cyanurates are prepared by comparable reactions.

The organic solvent dissolves the trinol and the cyanuric halide - as well as chlorides, and unctions as a medium for the reaction. The solvent can be a hydrocarbon, ketone, ester, ether, halogen solvent or a pyridine derivative, etc. Illustrative and non-limitative solvents include methylethyl ketone, methylisobutyl ketone, toluene and methylene chloride.

In general, the reaction is according to the following scheme: 3153/94 -4- (CH2Br)3CCH20— C C — OCH2C(CH2Br)3 N N I OCH2C(CH2Br)3 wherein each X is independently selected from CI, Br, I and F.

The plastic materials into which the above compounds can be used are many. Illustrative (but non-limitative) examples of suitable thermoplastic materials include high impact polystyrene (HIPS), polypropylene and its copolymers, and polbutylenterephthalate. The blends can be prepared in a variety of ways, such as by extrusion or injection molding.

The above and other characteristics and advantages of the invention will be further understood through the following description of illustrative and non-limitative examples. 3153/94 -5- Detailed Description of the Invention F.vamplp 1 Preparation of TTC Into a four-necked 3 Lit. glass flask equipped with thermometer, mechanical stirrer, dropping funnel and condenser, the following materials were charged: Methylene chloride 1200 g Trinol (ex Dead Sea Bromine, Israel) 975 g Cyanuric chloride 184.5 g Butyl tri-ethyl ammonium bromide 5 g The reaction mixture was cooled to 3°C by immersing the flask in an ice bath. NaOH 40% in H2O (340 g) was charged into the dropping funnel and added dropwise over 200 min. while the reaction temperature was maintained at 6°C.

The mixture was washed with 1200 ml of water and the aqueous phase was separated from the organic phase, the organic phase was washed again and separated form the water.

The organic solvent was distilled off from the product under vacuum. 1300 ml of methanol were added to the residue and the mixture was heated to 64°C. 230 ml of water were added and the mixture was cooled to 3153/94 -6- room temperature. The white powder product was filtered from the liquid and dried under vacuum.

The analysis was as follows: mp: 169°C Composition: Br - 68.84%; C - 20.86%; N- 4.24%; H - 2.16% Isothermal TGA at 240°C: 5.49 g weight loss after 30 min.

Exem li ¾ A blend was made of the following materials: 935 g High impact polystyrene (Vestaron 638 ex Huels) 44 g TTC (from Example 1) 11 g Antimony oxide, ex Laurel 3 g Acrawax C, ex Lonza 2 g Irganox B-225, ex Ciba-Geigy 0.5 g Irganox PS-720, ex Ciba-Geigy After mixing by shaking, the blend was transferred to a double-screw extruder. The melt, which was performed at approximately 210°C, was passed through a die to produce a single strand which was cooled and cut. The resin thus produced was molded in a 350 KN injection molding machine at a melting temperature of about 225°C. 3153/94 -7- The test pieces obtained were tested with the following resvilts: Test Result Flammability UL-94 3.2 mm V2 HDT 61°C Izod Notched Impact 78 J/m A blend was made from the following materials: Polypropylene homopolymer (HV 206 ex Solvay) 93.7% Antimony trioxide (ex Laurel) 1.5% TTC 4.4% Acrawax lubricant (ex Lonza) 0.3% The procedure of Example 2 was repeated. A reference sample containing the same materials was made under the same conditions: Polypropylene homopolymer (HV-206 ex Lonza) 99.7% Acrawax (ex Lonza) 0.3% Test pieces obtained were conditioned at room temperature for 10 days, and tested, with the following results: 3153/94 -8- EX 3 Ref. EX 2 Flammability UL-94 (3.2 mm) V2 NR* HDT (°C) 46.7 51.1 Izod Impact Notched(J/m) 28.3 29.5 *Not Rated.

Moreover, test pieces of Example 3 were placed in an air-circulating oven at 150°C for 30 days, after which flammability and impact were again tested, with the following results: Flammability UL-94 (3.2 mm) Izod Impact Notched (J/m) Exam l 4 (Comparative) Flame-retarded polypropylenes are made with different flame retardants, according to the procedures of Example 3.

Table I Formulation: Comt). EX 2 Como. EX 3 Propylene homopolymer 93.33 97.85 Antimony trioxide 1.5 0.47 Flame retardant **FR-1034 HBCD % FR 5 1.35 Mixxim T-18 0.2 0.2 Flammability UL-94 V-2 V-2 Flammability after 14 days @ 150°C N.R. N.R.

Tetrabromodipentaerithritol The thermal stability of the composition in accordance with the present invention is apparent from the above results. After heat aging at 150°C 3153/94 -9- for 30 days, a sample of the present invention retained high impact strength and flammability. In the comparative examples, the flammability test was not passed after only 14 days under the same conditions.

Claims (17)

3153/94 l l 1932/2 -lO- CLAIMS:

1. A flame-retarded thermoplastic polymer composition comprising a flame-retardant effective amount of a compound of the formula I wherein n=l,2 or 3; m=3-n; and R is chloro, bromo, amino, hydroxy or an organic radical, or a mixture thereof.

2. A flame-retarded polymeric composition according to claim 1, comprising 0.5-25 wt% of a compound of formula I, alone or together with other flame-retardant agents or additives.

3. A flame-retarded polymeric composition according to claim 1, wherein the compound of claim 1 is tris trinol cyanurate.

4. A flame-retarded composition according to claim 2, comprising (in wt%): TTC - 0.5-25% bromine-containing organic FRs 0 - 25% antimony oxide 0 - 15% phosphorous-containing FRs 0 - 20% 3153/94 111932/2 -11- conventional plastic additives.

5. A process for the preparation of tris trinol cyanurate, comprising reacting cyanuric halide with trinol in the presence of a proton scavenger.

6. A process according to claim 5, wherein the reaction is carried out in an organic solvent.

7. A process according to claim 6, wherein the organic solvent is selected from among methylethyl ketone, methylisobutyl ketone and toluene.

8. A process according to claim 7, wheisein the organic solvent is a halogenated solvent.

9. A process according to claim 8, wherein the halogenated solvent is methylene chloride.

10. A process according to any one of claims 5 to 9, wherein the proton scavenger is a base.

11. A process according to claim 10, wherein the base is NaOH.

12. A compound of formula I for use of as a flame-retardant blended material or thermoplastic polymers. 3153/94 111932/2 -12-

13. A compound of formula I as claimed in claim 12, which is blended in a thermoplastic material selected from among polystyrene, polystyrene foam, ABS resin, polypropylene, polyethylene, polyurethane, thermoplastic polyester, polymethyl methacrylate, styrene-acrilonitrile copolymers, and PVC.

14. A compound of formula I according to claim 13, wherein the plastic material is selected from among HIPS, polypropylene and its copolymers, and polybutylenterephthalate.

15. A compound of formula I according to any one of claims 12 to 14, which is TTC.

16. A compound of formula I according to any one of claims 11 to 15, wherein the blend is prepared by extrusion.

17. A compound of formula I according to any one of claims 11 to 16, wherein the blend is prepared by injection molding. LUZZATTO & LUZZATTO