Polymer Flame Retardant and Method for Its Manufacture

Abstract

Method for the preparation of a film forming flame retardant comprising nitrogen and silicon in its chemical composition, said method comprising the following steps: i. conversion of Z.sub.1 moles of amine moiety, selected from the group of primary and secondary amine and covalently bound to Z.sub.2 moles of one or more at least partially hydrolysable silane moiety, with Z.sub.3 moles of a chemical substance selected from a group of chemical substances obtainable from carboxylic acids or carbonic acid and represented by formula (I), (II) or (III); ii. conversion with a with at least one HO-functionalized substance of formula (IV): M.sub.x(OH).sub.yR.sup.5z. The resulting film forming flame retardant is contemplated.

Claims

1-17. (canceled)

18. A method for preparing a film forming flame retardant having nitrogen and silicon in its chemical composition, comprising the following steps: (i) reacting Z.sub.1 moles of an amine moiety selected from the group consisting of primary amine and secondary amine being covalently bound to Z.sub.2 moles of one or more at least partially hydrolysable silane moiety, with Z.sub.3 moles of a chemical substance selected from chemical substances obtainable from carboxylic acids or carbonic acid and represented by formula (I), (II) or (III): ##STR00018## wherein Z.sub.1 is an integer greater than 0, Z.sub.2 is an integer greater than 0, Z.sub.3 is an integer greater than 0, wherein Z.sub.1 is greater than each of Z.sub.2 and Z.sub.3; R.sup.1, R.sup.2, R.sup.3, R.sup.4 are independently selected from the group consisting of hydrogen, saturated C.sub.1-C.sub.24 alkyl, unsaturated C.sub.1-C.sub.24 alkyl, N-alkyl, C.sub.1-C.sub.12 alkylphenyl, aryl with 6 to 20 ring atoms, heterocyclyl with 5 to 20 ring atoms, optionally substituted by moieties selected from a group consisting of hydroxy, alkoxy, cyano and carbamoyl moieties, X.sub.1, X.sub.2 and X.sub.3 are independently selected from the group consisting of O, S and NH, wherein one or more of R.sup.2-R.sup.4 may be absent and a double or triple bond is present to the remaining R.sup.2-R.sup.4 group(s), to yield a first intermediary; (ii) reacting the first intermediary with at least one HO-functionalized substance of the formula (IV):
M.sub.x(OH).sub.yR.sup.5.sub.z  (IV); wherein M is selected from the group consisting of B, Al, Si, P, S, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Se, Y, and Zr, x, z are independently integers between 0 and 8, y is an integer between 1 and 8, at least one of x and z is not 0, and R.sup.5 is selected from the group consisting of H, saturated C.sub.1-C.sub.24 alkyl, unsaturated C.sub.1-C.sub.24 alkyl, and C.sub.1-C.sub.12 alkylphenyl.

19. The method according to claim 18, wherein M is selected from the group consisting of Al, Si and Fe.

20. The method according to claim 18, wherein the chemical substance of formula (I), (II) or (III) is selected from the group consisting of 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2-hydroxynaphtoic acid, 3-hydroxynaphtoic acid, 4-hydroxynaphtoic acid, 6-hydroxynaphtoic acid and esters or amides thereof, 2-hydroxybenzonitrile, 3-hydroxybenzon nitrile, 4-hydroxybenzon itri le, 2-hydroxynaphtonitrile, 3-hydroxynaphtonitrile, 4-hydroxynaphtonitrile, and hydroxynaphtonitrile.

21. The method according to claim 18, comprising the step of (iii) contacting the film forming flame retardant with at least one low flammable substance selected from the group consisting of inorganic oxides, hydroxides, carbonates, sulfates, phosphates, chlorides, bromides, carbohydrates, amides, melamines, ureas, guanidines, salts of guanidines, waxes, and thermoplastic materials.

22. The method according to claim 21, wherein the low flammable substance includes halogen.

23. The method according to claim 22, wherein M at least partly comprises Fe and the low flammable substance is a chlorinated sugar.

24. The method according to claim 18 wherein the film forming flame retardant is mixed with hydrophobic matter selected from a group consisting of binders, thermoplastics, thermosets, waxes, oils, fats, solvents prior to step (i), after step (i) or after step (ii).

25. The method according to claim 18, wherein the Z.sub.2 moles of one or more silane are partially hydrolysed before or after step (i).

26. The method according to claim 18, wherein clay is added in step (i), after step (i), in step (ii) or after step (ii).

27. A film forming flame retardant comprising nitrogen and silicon in its chemical composition, manufactured by conversion of Zi moles of primary amine moieties or secondary amine moieties or both primary and secondary amine moieties with Z.sub.3 moles of a chemical substance obtainable from carboxylic acids or carbonic acid and represented by formula (I), (II) or (III): ##STR00019## wherein Z.sub.1 is an integer greater than 0, Z.sub.2 is an integer greater than 0, Z.sub.3 is an integer greater than 0, wherein Z.sub.1 is greater than each of Z.sub.2 and Z.sub.3; R.sup.1, R.sup.2, R.sup.3, R.sup.4 are independently selected from the group consisting of hydrogen, saturated C.sub.1-C.sub.24 alkyl, unsaturated C.sub.1-C.sub.24 alkyl, N-alkyl, C.sub.1-C.sub.12 alkylphenyl, aryl with 6 to 20 ring atoms, heterocyclyl with 5 to 20 ring atoms, optionally substituted by moieties selected from a group consisting of hydroxy, alkoxy, cyano and carbamoyl moieties, X.sub.1, X.sub.2 and X.sub.3 are independently selected from the group consisting of O, S and NH, wherein said primary amine, secondary amine or both moieties having covalent bonds to Z.sub.2 moles of one or more at least partially hydrolysable silane.

28. The film forming flame retardant according to claim 27, comprising a content of solvent that is less than 10 g per 100 g of flame retardant.

29. The film forming flame retardant according to claim 27, comprising a content of solvent that is less than 2 g per 100 g of flame retardant.

30. The film forming flame retardant according to claim 27, wherein the film forming flame retardant is reacted with at least one HO-functionalized substance of formula (IV):
M.sub.x(OH).sub.yR.sup.5.sub.z  (IV), wherein M is selected from the group consisting of H, B, Al, Si, P, S, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Se, Y, and Zr, x, z are independently integers between 0 and 8, y is an integer between 1 and 8, at least one of x and z is not 0, and R.sup.5 is selected from the group consisting of H, saturated C.sub.1-C.sub.24 alkyl, unsaturated C.sub.1 -C.sub.24 alkyl, and C.sub.1 -C.sub.12 alkylphenyl.

31. The film forming flame retardant according to claim 27, wherein M is selected from the group consisting of H, Al, Si and Fe.

32. The film forming flame retardant according to claim 27, wherein the flame retardant is selected from the group represented by the chemical structures in formula (V), (VI), (VII) and (VIII): ##STR00020## wherein n is an even integer from 2 to 16, and R.sub.6 is selected from H, alkyl or clay, and two or more R.sub.6 are optionally connected to each other by covalent bonds.

33. The film forming flame retardant according to claim 30, wherein the flame retardant is selected from the group represented by the chemical structures in formula (V), (VI), (VII) and (VIII): ##STR00021## wherein n is an even integer from 2 to 16, and R.sub.6 is selected from H, alkyl or clay, and two or more R.sub.6 are optionally connected to each other by covalent bonds.

34. The film forming flame retardant according to claim 27, wherein the flame retardant is present in mixtures comprising low flammable substances selected from the group consisting of inorganic oxides, hydroxides, carbonates, sulfates, phosphates, chlorides, bromides, carbohydrates, amides, melamines, ureas, guanidines, salts of guanidines, waxes, thermoplastic materials, optionally including halogen, and combinations thereof.

35. The film forming flame retardant according to claim 27, wherein the flame retardant takes the form of an aqueous or water-dilutable solution or dispersion.

36. The film forming flame retardant according to claim 27, wherein the flame retardant is present on a surface selected from the group consisting of paper, cardboard and wood, or within wooden plates, boards, laminates and particle boards.

37. An article of manufacture comprising at least one of binders, thermoplastics, thermosets, waxes, oils, fats, solvents, wooden plates, boards, laminates, particle boards, further comprising at least one film forming flame retardant according to claim 27.

Description

EXAMPLE 6

[0068] Preparation of Film Forming Flame Retardant Step (i)

Z.sub.1=2

Z.sub.2=1

Z.sub.1/Z.sub.3=2

[0069] 1 mole of N-(2-Aminoethyl)-3-aminopropyl-trimethoxysilane [1760-24-3] is introduced in a 1000 ml 3-necked reaction flask and heated to 80° C. under stirring. 1 mole of 4-hydroxymethylbenzoate [99-76-3] is added as powder within 5-10 minutes. Heating is increased and the reaction mixture becomes clear at 120° C. The reaction mixture is slowly heated to 180° C. and about 50 g of destillate is collected. A clear colourless and slightly viscous product is obtained.

EXAMPLE 7

[0070] Preparation of Film Forming Flame Retardant Step (ii)

M═H

[0071] The product of example 6 is introduced in a 1000 ml 3-necked reaction flask and heated to 80° C. under stirring. H.sub.2O (3 moles) is added under vigorous stirring within 10-20 minutes. A clear product of low viscosity is obtained.

EXAMPLE 8

Burning Test of Cardboard

[0072] Packaging type cardboard (ca. 300 g/m.sup.2) has been coated with products obtained in Example 2, 3, 4, 5 and 7 and flame tested. The cardboard samples are about 8 cm in width and 20 cm in length. They are coated by brushing two times on the front side, which is exposed to the flame and one time on the backside. Drying has been performed for 10 min in an air stream at 80° C.

[0073] Flame: butane lighter with about 20 mm flame, top of flame in contact with cardboard sample for 60 seconds.

TABLE-US-00002 TABLE 2 Weight of burning text samples before and after fire test raw [g] coated [g] coating [g] after fire [g] loss [g] loss [%] reference 4.57 4.57 0.00 0.21 4.36 95.4% Example 2 4.61 5.28 0.67 4.80 0.48  9.1% Example 3 4.74 5.04 0.30 4.76 0.28  5.6% Example 4 4.81 5.44 0.63 5.11 0.33  6.1% Example 5 4.36 5.01 0.65 4.78 0.23  4.6% Example 7 3.86 4.50 0.64 4.41 0.09  2.0%

[0074] A clear difference between the uncoated reference and the coated samples has been found. All coated samples were self extinguishing within 5 seconds after removal of the butane flame. Weight loss is thoroughly less than 10% for the coated samples and more than 95% for the uncoated reference.

EXAMPLE 9

Burning Test of Corrugated Cardboard

[0075] Corrugated cardboard has been coated with the product obtained in Example 4 and flame tested. The cardboard samples are about 49 cm in width and 59 cm in length. They are coated by brushing two times on the front side, which is exposed to the flame and one time on the backside. Drying has been performed for 10 min in an air stream at 80° C.

[0076] Flame: butane torch with 3-4 kW effective heat and 15-20 cm flame. Distance between corrugated cardboard surface and torch nozzle: 2-3 cm.

TABLE-US-00003 coating raw [g] Area [m2] Coated [g] [g/m2] after fire [ ] loss [g] Loss [%] reference 168.3 0.29 168.3 0.0 7.0 161.3 95.8% Example 4 169.7 0.29 195.9 90.0 192.7 3.2  1.6%

[0077] A clear difference between the uncoated reference and the coated sample has been found. The coated sample was self extinguishing within less than 5 seconds after removal of the butane flame. Weight loss is less than 2% for the coated samples and more than 95% for the uncoated reference.

EXAMPLE 10

Burning Test of Particle Board

[0078] Particle board samples have been prepared from 12 mm particle boards (Forestia 3-vegg). Sample boards of 122 cm length and 50 cm width have been roll coated with the product from Example 4 and dried under infrared lamps (2 kW). Coated boards with dry coating weight of 100-120 g/m.sup.2 are obtained. Two sample boards have been connected on their long sides by four metal screws to form a 90 degree corner. Similar a reference corner has been made from uncoated boards.

[0079] Each of the corners has been installed in a steel chamber which is suitable for medium scale burning tests. 10 cm above the upper corner a paper stripe has been attached in order to test if the flames can exceed the top of the corner and spread above the corner. 600 g of gelatinized ethanol on about 100 g rockwool has been placed at the lower corner of the sample and ignited. After 20 minutes, the residues of burning gelatinized ethanol on rockwool have been removed.

Results

[0080] The reference sample started to burn vigorously after 2:50 minutes. After 4:00 minutes the flames reached and exceeded the upper corner. The paper stripe was ignited after 4:50 minutes.

[0081] The coated sample started to burn moderately after 4:30 minutes. The flames reached a maximum height of 70 cm (57% of total sample height). The upper corner was not reached by the flames and the paper stripe was not ignited.

[0082] The coated particle board would withstand a fire of about 20 kW heat for 20 min. The fire would not spread to burnable items above the board. The non-coated particle board would spread fire to burnable items above the board under similar conditions.

EXAMPLE 11

[0083] Preparation of Film Forming Flame Retardant Step (i) with Clay Added before Step (i)

Z.sub.1=2

Z.sub.2=1

Z.sub.1/Z.sub.3=2

[0084] 2 moles of N-(2-Aminoethyl)-3-aminopropyl-trimethoxysilane [1760-24-3] and 10 g of clay (Montmorillonite K-10, Aldrich) are introduced in a 1000 ml 3-necked reaction flask and heated to 80 ° C. under stirring. 2 mole of 4-hydroxymethylbenzoate [99-76-3] is added as powder within 5-10 minutes. Heating is increased and the reaction mixture becomes clear at 120 ° C. The reaction mixture is slowly heated to 180 ° C. and about 100 g of destillate is collected. A transparent greyish and slightly viscous product is obtained.

EXAMPLE 12

[0085] Preparation of Film Forming Flame Retardant Step (ii)

M═H

[0086] The product of example 11 is introduced in a 1000 ml 3-necked reaction flask and kept at 20 ° C. under stirring. H.sub.2O (3 moles) is added under vigorous stirring within 10-20 minutes. The temperature raises to 60° C. due to the exothermal hydrolysis and condensation of the silane groups. This is a clear indication for the formation of amidine groups in the film forming flame retardant.

[0087] Amide groups, which could be seen as an alternative product of the synthesis would not catalyse the hydrolysis and condensation in a similar way and thus the temperature would raise much slower and to a lower value.

[0088] 180 g of a 10% w/w solution of sodium hydroxide in water is thereafter added. A clear product of low viscosity is obtained.

EXAMPLE 13

[0089] Preparation of Film Forming Flame Retardant with Addition of Low Flammable Substances after Step (ii)

[0090] 50% w/w of the final product of example 12 is introduced in a 1000 ml 3-necked reaction flask and heated to 80° C. under stirring. A dispersion of freshly precipitated Fe(OH).sub.3 (0.1 moles) in H.sub.2O (6 moles), which additionally contains 0.1 moles of sucralose (1,6-Dichloro-1,6-dideoxy-β-D-fructofuranosyl-4-chloro-4-deoxy-α-D-galactopyranosid, [56038-13-2] and which pH is adjusted to 9-10 with sodium hydroxide is added under vigorous stirring within 10-20 minutes. A slightly redish product is obtained.

EXAMPLE 14

Burning Test of Particle Board

[0091] Particle board samples have been prepared from 12 mm particle boards (Forestia 3-vegg). Sample boards of 61 cm length and 15 cm width have been roll coated with the product from Example 12 and 13 and dried under infrared lamps (2 kW). Coated boards with dry coating weight of 170-200 g/m.sup.2 are obtained. Two sample boards have been connected on their long sides by four metal screws to form a 90 degree corner. Similar a reference corner has been made from uncoated boards.

[0092] Each of the corners has been installed in a steel chamber which is suitable for medium scale burning tests. 300 g of gelatinized ethanol in an aluminium char has been placed at the lower corner of the sample and ignited. After 20 minutes, the residues of burning gelatinized ethanol in the aluminium char have been removed. The heat release measured by weight loss was 7-8 kW during the 20 minutes test and the area covered by heat from the burning ethanol was 0.1-0.2 m.sup.2. The results are shown in the table below:

TABLE-US-00004 Maximum flame height Weight [%] of No. Type loss [%] sample height 1 Uncoated 24.9  >100 2 Example 12, 200 g/m.sup.2 7.4  <50 3 Example 13, 200 g/m.sup.2 5.7  <50 4 Example 13, 170 g/m.sup.2 5.7  <50

[0093] The weight loss and the maximum flame height of the particle board samples with film forming polymer is significantly lower than the respective weight loss and maximum flame height of the uncoated particle board sample.

EXAMPLE 15

[0094] Preparation of Film forming Flame Retardant Step (ii) and Burning Test of Cardboard

[0095] 10 g of the product of example 11 is mixed with 1.5 g glycerol (HO-functionalized substance) and warmed to 60° C. Strong foaming occurs due to the reaction of glycerol with the hydrolysable moieties followed by emission of methanol. The strong foaming is a clear indication for the melt strength and the film forming properties of the disclosed film forming flame retardant.

[0096] The product was diluted with 5 g of 10% w/w sodium hydroxide solution. 0.92 g were applied to a cardboard according to example 8 and subjected to the respective burning test. The weight loss due to the fire test was 8.7% w/w.