FLAME RETARDANT COMPOSITION AND FLAME RETARDANT THERMOPLASTIC POLYURETHANE COMPOSITION

Abstract

The present invention provides a flame retardant composition and a thermoplastic polyurethane composition both of which has excellent flame retardance. A phosphoramidate compound having a specific structure (component (B)) and a triazine-based compound (component (C)) are used as a flame retardant for a flame retardant composition and a flame retardant thermoplastic polyurethane composition. In one embodiment, the flame retardant thermoplastic polyurethane composition of the present invention includes a thermoplastic polyurethane resin (component (A)), a phosphoramidate compound (component (B)) and a triazine-based compound (component (C)).

Claims

1. A flame retardant composition comprising a phosphoramidate compound and a triazine-based compound, wherein the phosphoramidate compound is represented by the general formula (I): ##STR00021## wherein R.sub.1 and R.sub.2 are each independently hydrogen atom or an alkyl group in which the number of carbon atoms is 1 to 3, R.sub.11 and R.sub.12 are each independently an alkylene group in which the number of carbon atoms is 1 to 3, R.sub.13 is an alkylene group in which the number of carbon atoms is 1 to 6, B.sub.1 is a hydrogen atom or an alkyl group in which the number of carbon atoms is 1 to 6, and A is a hydrogen atom or an organic group represented by general formula (II): ##STR00022## wherein R.sub.3 and R.sub.4 are each independently hydrogen atom or an alkyl group in which the number of carbon atoms is 1 to 3, R.sub.14 and R.sub.15 are each independently an alkylene group in which the number of carbon atoms is 1 to 3, and B.sub.2 is a hydrogen atom or an alkyl group in which the number of carbon atoms is 1 to 6; and wherein when A is a hydrogen atom and B.sub.1 is an alkyl group in which the number of carbon atoms is 1 to 6, then B.sub.1 and R.sub.13-A may be bound to form a nitrogen-containing heterocycle with the nitrogen atom in the general formula (I), and when A is an organic group represented by the general formula (II), B2 is an alkyl group in which the number of carbon atoms is 1 to 6, and B.sub.1 is an alkyl group in which the number of carbon atoms is 1 to 6, then B.sub.1 and B2 may be bound to form a nitrogen-containing heterocycle with the nitrogen atom in the general formula (I), the nitrogen atom in the general formula (II) and R.sub.13, and wherein the triazine-based compound is a compound having a 1,3,5-triazine structure or a 1,3,5-triazine fused ring structure, or a salt thereof.

2. The flame retardant composition according to claim 1, wherein the triazine-based compound is a melamine, a condensate of melamine or a salt thereof.

3. The flame retardant composition according to claim 1, wherein the triazine-based compound is a salt of melamine.

4. The flame retardant composition according to claim 1, wherein the triazine-based compound is a cyanurate salt of melamine.

5. The flame retardant composition according to claim 1, wherein in the general formula (I), R.sub.1 and R.sub.2 are methyl groups, and R.sub.11 and R.sub.12 are methylene groups.

6. The flame retardant composition according to claim 1, wherein in the general formula (I), A is an organic group represented by the general formula (II), R.sub.3 and R.sub.4 are methyl groups, and R.sub.14 and R.sub.15 are methylene groups.

7. The flame retardant composition according to claim 6, wherein in the general formula (I), R.sub.13 is an alkylene group in which the number of carbon atoms is 1 to 2.

8. The flame retardant composition according to claim 6, wherein in the general formula (I), B.sub.1 and B.sub.2 are hydrogen atoms.

9. The flame retardant composition according to claim 6, wherein said phosphoramidate compound is represented by the formula (4): ##STR00023##

10. The flame retardant composition according to claim 1, wherein the mass ratio of “the phosphoramidate compound:triazine-based compound” is 1:9 to 9:1.

11. A flame retardant thermoplastic polyurethane composition comprising: a thermoplastic polyurethane resin, and the flame retardant composition according to claim 1.

12. The flame retardant thermoplastic polyurethane composition according to claim 11, wherein the thermoplastic polyurethane resin comprises polyether polyurethane, polyester polyurethane or polycarbonate polyurethane.

13. The flame retardant thermoplastic polyurethane composition according to claim 11, wherein the total amount of the phosphoramidate compound and the triazine-based compound in the flame retardant thermoplastic polyurethane composition is 7 to 50% by mass.

14. The flame retardant thermoplastic polyurethane composition according to claim 11 further comprising an antioxidant.

15. The flame retardant thermoplastic polyurethane composition according to claim 11, further comprising another additive.

Description

EXAMPLES

[0276] Hereinafter, the present invention is described in further detail by showing Examples and Comparative Examples.

[0277] (Compounding Procedure)

[0278] All components in the formulations of the Examples and Comparative Examples were extruded in a 24 mm twin screw extruder with a temperature profile in the range of 180° C.-190° C. to produce pellets. The polymer pellets were introduced in the main hopper, and a dry blend of additives was introduced in the first side feeder. The extruded polymer pellets were dried in an oven at 90° C. and thereafter sheets of different thickness were obtained by compression moulding. Sheets of 1.6 mm thickness were cut to obtain the specimens for UL-94 test and sheets of thickness 3 mm were cut to obtain the specimens suitable for LOI test procedure.

[0279] (UL-94 Test)

[0280] Flammability test was conducted and reported according to the UL-94 vertical test procedure. Two series of 5 specimens were conditioned for 24 hours at 23° C. and 50% humidity. When the test results do not meet V0, V1 and V2, an NC classification was given.

[0281] (LOI Test)

[0282] The LOI tests were carried out according to the ASTM D2863 procedure. The LOI is the minimum percentage of oxygen in a mixture of oxygen and nitrogen which allows a sample to sustain combustion under specified conditions in a candle-like geometry.

[0283] (Ingredients)

[0284] Aromatic Polyether Based Thermoplastic Polyurethane resin, hardness 85A (Estane 58311 NAT 028) (hereinafter, referred to as “TPU1”)

[0285] Cyclic phosphoramidate, an aliphatic bi-cyclic phosphoramidate compound of the aforementioned formula (4) (hereinafter, referred to as “ABCP”). ABCP was manufactured according to the procedure described in United States Patent Laid-open Application Publication No. 2016/0244582 in the paragraph [0173].

[0286] N,N 2-Bis (6-oxido-6H-dibenz [c,e][1,2]oxaphosphorin-6-yl)-1,2-ethanediamine (EDAB-DOPO, by Metadynea), a phosphorus nitrogen containing compound, (hereinafter, referred to as “EDAB-DOPO”)

[0287] Melamine cyanurate (Melagard MC25, by Italmatch Chemicals), a nitrogen containing compound, (hereinafter, referred to as “MC”)

[0288] Melamine (Melamine, by Sigma Aldrich), a nitrogen containing compound, (hereinafter, referred to as “MEL”)

[0289] Melem (Delacal 420, by Delamin), a nitrogen containing compound, (hereinafter, referred to as “DEL”)

[0290] Aluminium salt of di ethyl phosphinic acid (Exolit OP1240, by Clariant), a phosphorous containing compound (hereinafter, referred to as “OP1240”)

[0291] Aluminium hypophosphite (Phoslite B85AX, by Italmatch Chemicals), a phosphorus containing compound (hereinafter, referred to as “B85AX”)

[0292] 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide (AFLAMMIT PCO900, by THOR), a phosphorus containing compound (hereinafter, referred to as “PCO900”)

[0293] Melamine phosphate (Melagard MP, by Italmatch Chemicals), a phosphorus nitrogen containing compound, (hereinafter, referred to as “MP”)

[0294] Ammonium polyphosphate (Exolit AP 422), a phosphorus containing compound (hereinafter, referred to as “APP”)

[0295] Talc (STEAMIC T1 CA, by Imerys), hereafter “TALC”

[0296] Resorcinol bis(diphenyl phosphate) (Fyrolflex RDP, by ICL Industries), a phosphorus containing compound, (hereinafter, referred to as “RDP”)

[0297] Blend of 20% by mass of Irganox 1010, a hindered phenol heat stabilizer, and 80% by mass Irgaphos 168, a phosphite process stabilizer, (Irganox B 561, by BASF) (hereinafter, referred to as “B 561”)

TABLE-US-00001 TABLE 1A E.4 E.5 E.6 C.1 C.2 C.3 C.7 TPU1 (%) 91.8 89.8 89.8 99.8 49.8 69.8 79.8 ABCP 2% 2.5% 7.5% — — — — MC 6% 7.5% 2.5% — 50% 30% 15% EDAP-DOPO — — — — — —  5% OP 1240 — — — — — — — B85AX — — — — — — — PCO900 — — — — — — — APP — — — — — — — RDP — — — — — — — MP — — — — — — — B561 0.2%   0.2% 0.2% 0.2% 0.2%  0.2%  0.2%  UL-94 (1.6 mm) V0 V0 V0 V2 V2 V2 V2 LOI 26.8 26.9 27.0 — 26.5 23.1 —

TABLE-US-00002 TABLE 1B C.8 C.9 C.10 C.11 C.12 C.13 C.14 TPU1 (%) 79.8 79.8 79.8 79.8 79.8 79.8 79.8 ABCP — — — — — — — MC — 15% — 15% — 15% — EDAP-DOPO 20% — — — — — — OP 1240 —  5% 20% — — — — B85AX — — —  5% 20%   — PCO900 — — — — —  5% 20% APP — — — — — — — RDP — — — — — — — MP — — — — — — — B561 0.2%  0.2%  0.2%  0.2%  0.2%  0.2%  0.2%  UL-94 (1.6 mm) V2 V2 V2 V2 V2 V2 V2 LOI — — — — — — —

TABLE-US-00003 TABLE 1C C.15 C.16 C.17 C.18 C.19 C.20 TPU1 (%) 79.8 79.8 79.8 79.8 79.8 79.8 ABCP — — — — — — MC 15% — 15% — 15% — EDAP-DOPO — — — — — — OP 1240 — — — — — — B85AX — — — — — — PCO900 — — — — — — APP  5% 20% — — — — RDP — —  5% 20% — — MP — — — —  5% 20% B561 0.2%  0.2%  0.2%  0.2%  0.2%  0.2%  UL-94 (1.6 mm) V2 V2 V2 V2 V2 V2 LOI — — — — — —

TABLE-US-00004 TABLE 2A E.21 E.22 E.23 E.24 TPU1 89.8% 84.8% 74.8% 74.8% ABCP   5%  7.5% 12.5% 12.5% MC   5%  7.5% 12.5% MEL 12.5% DEL TALC B561  0.2%  0.2%  0.2%  0.2% UL-94 V0 V0 V0 V0 (1.6 mm) LOI 26.2  27.0  26.9  29.5 

TABLE-US-00005 TABLE 2B E.25 E.26 E.27 E.28 E.29 E.30 TPU1 74.8% 74.8% 74.8% 74.8% 59.8% 74.8% ABCP 12.5%   5%   5%   5%   20%   10% MC   20%   15%   10% MEL   20%   5%   20% DEL 12.5% TALC   5% B561  0.2%  0.2%  0.2%  0.2%  0.2%  0.2% UL-94 (1.6 mm) V0 V0 V0 V0 V0 V0 LOI 27.4 25.8 28.2 27.7 31.1 25.6

Consideration on the Examples and Comparative Examples

[0298] From the results of Comparative example C.1 in Table 1A, it is understood that TPU without flame retardant has a performance of V2 in the UL-94 test.

[0299] From the results of Comparative example C.2 and Comparative example C.3, it is understood that when melamine cyanurate is used alone, a LOI value higher than 24 is achieved in the range of 30% by mass to 50% by mass. However, V0 classification is not achieved in the UL-94 test even at a concentration of 50% by mass.

[0300] From the results of Comparative examples C.8, C.10, C.12, C.14, C.16, C.18 and C.20, it is understood that phosphorus containing compounds which are different from the phosphoramidate compounds in an amount of 20% by mass loading are not sufficient to achieve V0 classification in the UL-94 test.

[0301] From the results of Example E.4, it is understood that a combination of cyclic phosphoramidate compound and melamine cyanurate at 8% by mass loading is able to achieve V0 classification in the UL-94 test. The Examples E.5, E.6 and E.21 show that a mixture of a cyclic phosphoramidate compound and melamine cyanurate, also in different ratio, at 10% by mass loading is able to achieve V0 classification in the UL94 test and LOI higher than 24. In the cases where another flame retardant or another combination of flame retardants is used, such a small amount cannot achieve V0 classification in the UL-94 test. That is, a small amount of the combination of cyclic phosphoramidate compound and melamine cyanurate can achieve a high flame-retardance effect.

[0302] From the results of Comparative examples C.7, C.9, C.11, C.13, C.15, C.17 and C.19, it is understood that 20% by mass of a combination of a phosphorus containing compound which is different from the phosphoramidate compounds and melamine cyanurate is not sufficient to achieve V0 classification in the UL-94 test.

[0303] From the results shown in Tables 2A and 2B, it is understood that a mixture of cyclic phosphoramidate and triazine-based compound, according to the present invention, in the ratio between 4:1 to 1:4 at a concentration from 8% to 40% by mass with respect to total composition is very efficient as flame retardant for TPU.

[0304] The results in table 2B shown that the a mixture of phosphoramidate compound with melamine or a condensate of melamine as a triazine-based compound are useful to further increase LOI of the flame retardant thermoplastic polyurethane compositions of the present invention.

[0305] Moreover, Example E.30 shows that also with a filler like talc, the flame retardant performances is also able to achieve V0 classification in the UL-94 test and LOI higher than 24.

INDUSTRIAL APPLICABILITY

[0306] According to the present invention, excellent flame retardance is provided to a thermoplastic polyurethane resin composition.

[0307] The present invention has been exemplified so far with reference to the favorable embodiments of the present invention, but it should not be construed that the present invention is restricted by the embodiments. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those who are skilled in the art can carry out an equivalent range based on the description of the present specification and technical common sense from the description of the specific favorable embodiments of the present invention. It is understood that the contents of the patents, patent applications and literatures cited in the present specification should be herein incorporated by reference, similarly to the case where the contents themselves are described specifically in the present specification.