MELAMINE FORMALDEHYDE FOAM WITH REDUCED FORMALDEHYDE EMISSION

Abstract

Method for lowering the formaldehyde emissions of melamine/formaldehyde polymer moldings, films or fibers by impregnating the melamine/formaldehyde polymer moldings, films or fibers with an aqueous solution of at least one formaldehyde scavenger.

Claims

1.-11. (canceled)

12. Method for lowering the formaldehyde emissions of melamine/formaldehyde polymer moldings made from melamine/formaldehyde foams by impregnating the melamine/formaldehyde polymer moldings made from melamine/formaldehyde foams with an aqueous solution of at least one formaldehyde scavenger selected from acetoacetamide and compounds containing acetoacetamide groups.

13. Method for preparing melamine/formaldehyde polymer moldings made from melamine/formaldehyde foams with low formaldehyde emissions, by first preparing a molding made from melamine/formaldehyde foams of a melamine/formaldehyde polymer and subsequently impregnating the surface of the melamine/formaldehyde polymer molding made from melamine/formaldehyde foams with an aqueous solution of at least one formaldehyde scavenger selected from acetoacetamide and compounds containing acetoacetamide groups.

14. Use of an aqueous solution containing a formaldehyde scavenger selected from acetoacetamide and compounds containing acetoacetamide groups and being free from polyurethanes, melamine/formaldehyde polymers, or mixtures, prepolymers or monomers thereof for impregnating melamine/formaldehyde foam moldings.

15. The use according to claim 14, wherein the aqueous solution contains 0.1 to 25 wt % of the formaldehyde scavenger, based on the total weight of the solution.

16. Shaped article of melamine/formaldehyde foam obtainable by the following process: a) a foam is prepared from a melamine/formaldehyde precondensate, b) the foam obtained is annealed at below 250° C., c) the annealed foam article is impregnated with an aqueous solution of a formaldehyde scavenger selected from acetoacetamide and compounds containing acetoacetamide groups, d) the impregnated annealed foam is dried.

17. Shaped article according to claim 16, wherein the amount of formaldehyde scavenger, based on the dried impregnated shaped article, is from 0.025 to 10 wt.

18. Shaped articles according to claim 16, wherein in step a) the foam is prepared by a process comprising the steps of: aa) producing an aqueous mixture M1) comprising 100 parts by weight of at least one melamine/formaldehyde precondensate, 2 to 4 parts by weight of at least one curative, 0.2 to 5 parts by weight of a surfactant or surfactant mixture, 0.1 to 5 parts by weight of at least one salt of an inorganic acid or one salt of an organic carboxylic acid, 1 to 40 parts by weight of at least one blowing agent, 0 to 5 parts by weight of at least one dye or optical brightener, 0 to 20 parts by weight of one or more further additives, and 25 to 60 parts by weight of water, ab) heating and foaming said mixture M1) using microwave radiation, ac) crosslinking and curing the resulting foam using the curative and microwave radiation, ad) drying the foam using microwave radiation.

19. Shaped article according to claim 16, wherein the annealed foam is shaped by cutting or mechanical abrasion of the annealed foam, prior to or after impregnation, or wherein the annealed foam is molded in a press to give a shaped article, or wherein the foam is prepared in a mold of the desired shape.

20. Method, solution, use or shaped article according to claim 12, wherein the formaldehyde scavenger is selected from the group consisting of acetoacetamide, ethylenediamine bis-acetoacetamide, N-methylacetoacetamide, N,N-dimethyl acetoacetamide, 2-cyano acetoacetamide, or mixtures thereof.

21. Shaped article of melamine/formaldehyde foam, impregnated with a formaldehyde scavenger, selected from acetoacetamide, molecules containing covalently linked acetoacetamide groups, and mixtures thereof.

22. The shaped article according to claim 21, wherein the amount of formaldehyde scavenger is from 0.025 to 10 wt %, based on the impregnated melamine/formaldehyde foam.

Description

EXAMPLES

[0045] A melamine/formaldehyde foam (Basotect®) was prepared according to Example 2 of US 2015/0210814 A1. The foam had a density of 8 to 10 g/l. A molding in the form of a foam sheet was cut from the melamine/formaldehyde foam.

[0046] A impregnating solution was prepared by dissolving 1 to 25 wt % of ethylenediamine-N,N′-bis(acetoacetamide) or of acetoacetamide in water. The impregnated active amount refers to the impregnated active without water, based on the dry foam.

[0047] The following results for the formaldehyde (FA) emission from the melamine/formaldehyde foam molding (Basotect®) were obtained:

TABLE-US-00001 Impregnated active [wt %, based on foam molding] 0.1 0.2 0.5 mg FA/kg Basotect ® (acetoacetamide)* 3 2 0 mg FA/kg Basotect ® 1 1 0 (ethylenediamine-N,N′-bis(acetoacetamide))* *Basotect ® reference without impregnation: 22

TABLE-US-00002 Impregnated active [%] 50 25 12 mg FA/kg Basotect ® (acetoacetamide)* 0 0 0 mg FA/kg Basotect ® 0 0 — (ethylenediamine-N,N′-bis(acetoacetamide))* *Basotect ® reference with water impregnation: 162-171

[0048] Result of AgBB test:

[0049] Emissions after 28 days:

TABLE-US-00003 Basotect ® X1 Basotect ® X2 maximum (0.1% EA) (1% EA) Basotect ® G+ (AgBB) TVOC <0.005 mg/m.sup.3 <0.005 mg/m.sup.3 <0.005 mg/m.sup.3 ≤1 mg/m.sup.3 TSVOC <0.005 mg/m.sup.3 <0.005 mg/m.sup.3 <0.005 mg/m.sup.3 ≤0.1 mg/m.sup.3 Total carcinogens <0.001 mg/m.sup.3 <0.001 mg/m.sup.3 <0.001 mg/m.sup.3 ≤0.001 mg/m.sup.3 Formaldehyde <0.003 mg/m.sup.3 <0.003 mg/m.sup.3 0.0055 mg/m.sup.3 ≤0.1 mg/m.sup.3 EA: Ethylenediamine-N,N′-bis(acetoacetamide), amount in wt % based on the foam molding Basotect ® G+: Melamine/formaldehyde foam molding without impregnation Maximum (AgBB): The maximum values allowed by the AgBB test, the AgBB test was performed according to the art TVOC: Total volatile organic compounds TSVOC: Total semi-volatile organic compounds