Intumescent flame-retardant clearcoat formulations

Abstract

The invention relates to intumescent flame-retardant clearcoat formulations containing 20% to 88.5% by weight of an aqueous synthetic resin formulation, 10% to 60% by weight of a phosphoric partial ester, 0.5% to 20% by weight of a polyol and 1% to 30% by weight of further ingredients, and to the use thereof.

Claims

1. An intumescent flame-retardant clearcoat formulation comprising 30% to 75% by weight of an aqueous synthetic resin formulation, 20% to 50% by weight of a phosphoric partial ester, 3% to 15% by weight of at least one polyol, and 2% to 20% by weight of further ingredients, wherein the phosphoric partial ester is a partial ester of polyphosphoric acid and at least 2 polyols, the polyols having an average hydroxyl group content of at least 40% by weight, calculated as the ratio of hydroxyl group molecular weight to total polyol molecular weight multiplied by 100%.

2. The intumescent flame-retardant clearcoat formulation according to claim 1, containing 40% to 60% by weight of the aqueous synthetic resin formulation, 30% to 40% by weight of the phosphoric partial ester, 5% to 10% by weight of the at least one polyol, and 5% to 15% by weight of the further ingredients.

3. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the at least one polyol is selected from pentaerythritol, dipentaerythritol, tripentaerythritol, polycondensates of pentaerythritol, mixtures of pentaerythritol-based esters, glycerol, oligomeric glycerol, xylitol, sorbitol, mannitol, isomalt, lactitol, glucitol, threitol, erythritol, arabitol, inositol, polyvinyl alcohol, ethylene oxide-propylene oxide polyols, and mixtures of these.

4. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the at least one polyol is sorbitol.

5. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the phosphoric partial ester is a partial ester of polyphosphoric acid and at least 2 polyols, the polyols having an average hydroxyl group content of at least 45% by weight, calculated as the ratio of hydroxyl group molecular weight to total polyol molecular weight multiplied by 100%.

6. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the aqueous synthetic resin formulation is a nitrogen-containing synthetic resin formulation.

7. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the aqueous synthetic resin formulation is a melamine-formaldehyde resin, a urea- formaldehyde resin, or a mixture of these.

8. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the aqueous synthetic resin formulation is an etherified melamine-formaldehyde resin, an etherified urea-formaldehyde resin, or a mixture of these.

9. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the intumescent flame-retardant clearcoat formulation has a phosphorus content after curing of 1% to 15% by weight.

10. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the intumescent flame-retardant clearcoat formulation has a phosphorus content after curing of 5% to 10% by weight.

11. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the further ingredients are dispersants, fillers, curing agents, thixotropic agents, plasticizers, acid donors, further flame retardants, surface auxiliaries, binders, or a mixture of these.

12. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the intumescent flame-retardant clearcoat formulation is transparent after application and drying.

13. The intumescent flame-retardant clearcoat formulation according to claim 1, wherein the intumescent flame-retardant clearcoat formulation is free of halogens.

14. A method for providing an intumescent coating or impregnation, comprising the step of contacting an article made of wood, wood material, veneer, plastic, building material, cellulose material, rubber, metal, synthetic or natural fiber fabric, textile, leather, or polyolefin with the intumescent flame-retardant clearcoat formulation according to claim 1.

15. An intumescent flame-retardant clearcoat formulation containing 30% to 75% by weight of a nitrogen-containing aqueous synthetic resin formulation selected from a melamine-formaldehyde resin, a urea-formaldehyde resin, an etherified melamine-formaldehyde resin, an etherified urea-formaldehyde resin, and mixtures of these, 20% to 45% by weight of a phosphoric partial ester, 3% to 15% by weight of at least one polyol selected from pentaerythritol, dipentaerythritol, tripentaerythritol, polycondensates of pentaerythritol, mixtures of pentaerythritol-based esters, glycerol, oligomeric glycerol, xylitol, sorbitol, mannitol, isomalt, lactitol, glucitol, threitol, erythritol, arabitol, inositol, polyvinyl alcohol, ethylene oxide-propylene oxide polyols, and mixtures of these, and 2% to 20% by weight of further ingredients, wherein the phosphoric partial ester is a partial ester of polyphosphoric acid and at least 2 polyols, the polyols having an average hydroxyl group content of at least 40% by weight, calculated as the ratio of hydroxyl group molecular weight to total polyol molecular weight multiplied by 100%.

16. The intumescent flame-retardant clearcoat formulation according to claim 15, containing 40% to 60% by weight of the nitrogen-containing aqueous synthetic resin formulation, 30% to 40% by weight of the phosphoric partial ester, 5% to 10% by weight of the at least one polyol, and 5% to 15% by weight of the further ingredients.

17. The intumescent flame-retardant clearcoat formulation according to claim 15, wherein the nitrogen-containing aqueous synthetic resin formulation is selected from an etherified melamine-formaldehyde resin, an etherified urea-formaldehyde resin, and mixtures of these.

18. The intumescent flame-retardant clearcoat formulation according to claim 15, wherein the phosphoric partial ester is a partial ester of polyphosphoric acid and at least 2 polyols, the polyols having an average hydroxyl group content of at least 45% by weight, calculated as the ratio of hydroxyl group molecular weight to total polyol molecular weight multiplied by 100%.

19. The intumescent flame-retardant clearcoat formulation according to claim 15, wherein the at least one polyol is sorbitol.

20. The intumescent flame-retardant clearcoat formulation according to claim 15, wherein the intumescent flame-retardant clearcoat formulation has a phosphorus content after curing of 1% to 15% by weight.

Description

EXAMPLE 1 (COMPARATIVE)

(1) TABLE-US-00001 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Budit 380 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 2

(2) TABLE-US-00002 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 3

(3) TABLE-US-00003 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 5.38 pbw Chinafill 100 2.0 pbw Exolit AP 422 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 4

(4) TABLE-US-00004 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 4.38 pbw Chinafill 100 3.00 pbw Exolit AP 422 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 5

(5) TABLE-US-00005 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 3.38 pbw Chinafill 100 4.00 pbw Exolit AP 422 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 6

(6) TABLE-US-00006 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 9.23 pbw 70% glycerol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 7

(7) TABLE-US-00007 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 9.23 pbw 70% inositol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

(8) TABLE-US-00008 TABLE 1 Example 1 Name (comparative) 2 3 4 5 6 7 Amounts and type of 47.90 pbw 47.90 pbw 47.90 pbw 47.90 pbw 47.90 pbw 47.90 pbw 47.90 pbw aqueous synthetic resin Maprenal Maprenal Maprenal Maprenal Maprenal Maprenal Maprenal formulation (melamine- MF MF MF MF MF MF MF formaldehyde resin) 920w/75WA 920w/75WA 920w/75WA 920w/75WA 920w/75WA 920w/75WA 920w/75WA Foam-forming substance 32.65 pbw 32.65 pbw 32.65 pbw 32.65 pbw 32.65 pbw 32.65 pbw 32.65 pbw (partial phosphoric ester) Budit 380 Exolit 855 Exolit 855 Exolit 855 Exolit 855 Exolit 855 Exolit 855 Foam-forming substance 0 pbw 0 pbw 2.0 pbw 3.0 pbw 4.0 pbw 0 pbw 0 pbw (ammonium polyphosphate) Exolit AP 422 Exolit AP 422 Exolit AP 422 Exolit AP 422 Exolit AP 422 Exolit AP 422 Exolit AP 422 Carbon-forming substance 9.23 pbw 9.23 pbw 9.23 pbw 9.23 pbw 9.23 pbw 9.23 pbw 9.23 pbw (carbohydrates) sorbitol sorbitol sorbitol sorbitol sorbitol glycerol inositol Reaction accelerator 2.34 pbw 2.34 pbw 2.34 pbw 2.34 pbw 2.34 pbw 2.34 pbw 2.34 pbw p-toluene- p-toluene- p-toluene- p-toluene- p-toluene- p-toluene- p-toluene- sulfonic acid sulfonic acid sulfonic acid sulfonic acid sulfonic acid sulfonic acid sulfonic acid Modifier 7.38 pbw 7.38 pbw 5.38 pbw 4.38 pbw 3.38 pbw 7.38 pbw 7.38 pbw Chinafill Chinafill Chinafill Chinafill Chinafill Chinafill Chinafill Surface additive 0.5 pbw 0.5 pbw 0.5 pbw 0.5 pbw 0.5 pbw 0.5 pbw 0.5 pbw BYK 333 BYK 333 BYK 333 BYK 333 BYK 333 BYK 333 BYK 333 pbw = parts by weight

EXAMPLE 8

(9) TABLE-US-00009 47.90 pbw Maprenal MF 921w/85WA 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 9

(10) TABLE-US-00010 32.90 pbw Maprenal MF 921w/85WA 15.00 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 10

(11) TABLE-US-00011 15.00 pbw Maprenal MF 921w/85WA 32.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 11

(12) TABLE-US-00012 47.90 pbw Resimene AQ-2610 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 12

(13) TABLE-US-00013 15.00 pbw Maprenal MF 921w/85WA 32.90 pbw Resimene AQ-2610 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 13

(14) TABLE-US-00014 32.90 pbw Maprenal MF 921w/85WA 15.00 pbw Resimene AQ-2610 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 14

(15) TABLE-US-00015 47.90 pbw Primere 70 0867L 32.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

(16) TABLE-US-00016 TABLE 2 Example Name 8 9 10 11 Amounts and type of film- 47.90 pbw 15 pbw 32.90 pbw 47.90 pbw forming binder and blowing Maprenal MF Maprenal MF Maprenal MF Resimene agent (melamine- 921w/85WA 920w/75WA 920w/75WA AQ-2610 formaldehyde resin) 32.90 pbw 15 pbw Maprenal MF Maprenal MF 921w/85WA 921w/85WA Foam-forming substance 32.65 pbw 32.65 pbw 32.65 pbw 32.65 pbw (partial phosphoric ester) Exolit 855 Exolit 855 Exolit 855 Exolit 855 Foam-forming substance 0 pbw 0 pbw 0 pbw 0 pbw (ammonium polyphosphate) Exolit AP 422 Exolit AP 422 Exolit AP 422 Exolit AP 422 Carbon-forming substance 9.23 pbw 9.23 pbw 9.23 pbw 9.23 pbw (carbohydrates) sorbitol sorbitol sorbitol sorbitol Reaction accelerator 2.34 pbw 2.34 pbw 2.34 pbw 2.34 pbw p-toluene- p-toluene- p-toluene- p-toluene- sulfonic acid sulfonic acid sulfonic acid sulfonic acid Modifier 7.38 pbw 7.38 pbw 7.38 pbw 7.38 pbw Chinafill Chinafill Chinafill Chinafill Surface additive 0.5 pbw 0.5 pbw 0.5 pbw 0.5 pbw BYK 333 BYK 333 BYK 333 BYK 333 Example Name 12 13 14 Amounts and type of film- 15 pbw 32.90 47.90 pbw forming binder and blowing Maprenal MF Maprenal MF Primere 70 agent (melamine- 920w/75WA 920w/75WA 0867L formaldehyde resin) 32.90 pbw 15 pbw Resimene Resimene AQ-2610 AQ-2610 Foam-forming substance 32.65 pbw 32.65 pbw 32.65 pbw (partial phosphoric ester) Exolit 855 Exolit 855 Exolit 855 Foam-forming substance 0 pbw 0 pbw 0 pbw (ammonium polyphosphate) Exolit AP 422 Exolit AP 422 Exolit AP 422 Carbon-forming substance 9.23 pbw 9.23 pbw 9.23 pbw (carbohydrates) sorbitol sorbitol sorbitol Reaction accelerator 2.34 pbw 2.34 pbw 2.34 pbw p-toluene- p-toluene- p-toluene- sulfonic acid sulfonic acid sulfonic acid Modifier 7.38 pbw 7.38 pbw 7.38 pbw Chinafill Chinafill Chinafill Surface additive 0.5 pbw 0.5 pbw 0.5 pbw BYK 333 BYK 333 BYK 333 pbw = parts by weight

EXAMPLE 15

(17) TABLE-US-00017 47.90 pbw Maprenal MF 920w/75WA 41.88 pbw Exolit 855 0.00 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw Hypersal XT 782

EXAMPLE 16

(18) TABLE-US-00018 47.90 pbw Maprenal MF 920w/75WA 27.65 pbw Exolit 855 14.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw Hypersal XT 782

EXAMPLE 17

(19) TABLE-US-00019 37.90 pbw Maprenal MF 920w/75WA 42.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw Hypersal XT 782

EXAMPLE 18 (COMPARATIVE)

(20) TABLE-US-00020 57.90 pbw Maprenal MF 920w/75WA 12.65 pbw Exolit 855 9.23 pbw 70% sorbitol solution in water 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 19

(21) TABLE-US-00021 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 9.23 pbw Genamin Gluco 50 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 20

(22) TABLE-US-00022 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 4.00 pbw 70% sorbitol solution in water 5.23 pbw Genamin Gluco 50 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

EXAMPLE 21

(23) TABLE-US-00023 47.90 pbw Maprenal MF 920w/75WA 32.65 pbw Exolit 855 5.23 pbw 70% sorbitol solution in water 4.00 pbw Genamin Gluco 50 7.38 pbw Chinafill 100 2.34 pbw p-toluenesulfonic acid 0.5 pbw BYK 333

(24) TABLE-US-00024 TABLE 3 Example 18 Name 15 16 17 (comparative) 19 20 21 Amounts and type of film- 47.90 pbw 47.90 pbw 37.90 57.90 47.90 pbw 47.90 pbw 47.90 pbw forming binder and Maprenal Maprenal Maprenal Maprenal Maprenal Maprenal Maprenal blowing agent (melamine- MF MF MF MF MF MF MF formaldehyde resin) 920w/75WA 920w/75WA 920w/75WA 920w/75WA 920w/75WA 920w/75WA 920w/75WA Foam-forming substance 41.88 pbw 27.65 pbw 42.65 pbw 12.65 pbw 32.65 pbw 32.65 pbw 32.65 pbw (partial phosphoric ester) Exolit 855 Exolit 855 Exolit 855 Exolit 855 Exolit 855 Exolit 855 Exolit 855 Foam-forming substance 0 pbw 0 pbw 0 pbw 0 pbw 0 pbw 0 pbw 0 pbw (ammonium polyphosphate) Exolit AP 422 Exolit AP 422 Exolit AP 422 Exolit AP 422 Exolit AP 422 Exolit AP 422 Exolit AP 422 Carbon-forming substance 0 pbw 14.23 pbw 9.23 pbw 9.23 pbw 9.23 pbw 4.0 pbw 5.23 pbw (carbohydrates)/amino sorbitol sorbitol sorbitol sorbitol Genamin sorbitol sorbitol alcohol Gluco 50 5.23 pbw 4.0 pbw Genamin Genamin Gluco 50 Gluco 50 Reaction accelerator 2.34 pbw 2.34 pbw 2.34 pbw 2.34 pbw 2.34 pbw 2.34 pbw 2.34 pbw p-toluene- p-toluene- p-toluene- p-toluene- p-toluene- p-toluene- p-toluene- sulfonic acid sulfonic acid sulfonic acid sulfonic acid sulfonic acid sulfonic acid sulfonic acid Modifier 7.38 pbw 7.38 pbw 7.38 pbw 7.38 pbw 7.38 pbw 7.38 pbw 7.38 pbw Chinafill Chinafill Chinafill Chinafill Chinafill Chinafill Chinafill Surface additive 0.5 pbw 0.5 pbw 0.5 pbw 0.5 pbw 0.5 pbw 0.5 pbw 0.5 pbw Hypersal XT Hypersal XT Hypersal XT BYK 333 BYK 333 BYK 333 BYK 333 782 782 782 pbw = parts by weight

(25) Testing of the quality of the clearcoat formulations of the invention with regard to heat emission rate and transparency

(26) Materials that are used on board rail vehicles and are applied to vertical surfaces indoors and to other surfaces must meet corresponding demands with regard to heat emission rate under the action of thermal radiation. The heat emission rate is ascertained by irradiating a specimen in a horizontal position. The procedure of testing and assessment of the results is based on standards ISO 5660-1 and DIN EN 45545-2.

(27) The assessment criterion according to EN45545-2 for tests on a cone calorimeter is the MARHE value. This is the maximum of the average heat emission rate over the period of the measurement and is ascertained as the average from 3 individual tests. The MARHE value gives the corresponding hazard level (HL2<90 kW/m.sup.2; HL3<60 kW/m.sup.2).

(28) An amount of 400 g/m.sup.2 of each intumescent formulation thus produced was applied to a solid spruce board (10010020 mm) and subjected to a heat emission test to ISO 5660-1 (cone calorimeter test). The MARHE value indicates the heat emission rate based on surface area (kW/m.sup.2) under the chosen test parameters. The lower the heat emission, the better the insulating effect of the intumescent coating.

(29) Transparency

(30) The ability of material to transmit light waves is referred to as transparency. A material is described as transparent if it is transparent to visible light having a wavelength in the range from 380 nanometres (nm) to 780 nm. Thus, a material, for instance window glass, is described as being transparent if it is possible to see what lies behind it relatively clearly. This is also true within the scope of the invention.

(31) This gave the test results shown in table 4.

(32) TABLE-US-00025 TABLE 4 Intumescent formulation MARHE value Visual test* from (kW/m.sup.2) Grade Blank: uncoated spruce wood 148 Example 1 (comparative) 75 5 Example 2 33 1 Example 3 4 2 Example 4 4 2 Example 5 5 3 Example 9 62 2 Example 10 66 1 Example 11 70 2 Example 14 68 2 Example 15 71 1 Example 3 45 2 Example 18 (comparative) 80 5 Example 19 40 2 *For the visual test, the respective intumescent formulation is applied in defined layer thickness to a test chart for visual assessment of hiding capacity to ISO 6504-3.

(33) The assessment is made by a German school grade system, where grade 1 means highest transparency, no haze down to grade 6: low transparency, significant haze).

(34) The clearcoat formulations of the invention using phosphoric partial esters (Exolit 855 here) are all transparent and therefore of excellent suitability for production of effective transparent intumescent coatings.

(35) In addition, the clearcoat formulations of the invention have only low heat emissions, as apparent from the MARHE values. Thus, the clearcoat formulations of the invention in the form of an intumescent coating have a good insulating effect.