FORMALDEHYDE-SCAVENGING FORMULATION

Abstract

The present invention is concerned with improved formaldehyde-scavenging formulations, and uses of same in veils and construction products including ceiling tiles, boards including insulation boards, particularly phenolic insulation boards, and panels and boards including wood panels and wood boards, together with methods for reduction of formaldehyde emissions from a construction product.

Claims

1. A formaldehyde-scavenging formulation comprising: (a) formaldehyde scavenger (1-90% by weight dry mass), wherein the formaldehyde scavenger is polyvinylamine or a copolymer thereof, and/or a primary amine functionalised silane; (b) binder and/or crosslinker (<=60% by weight dry mass); and (c) antifoaming agent (<0.5% by weight dry mass); and at least one of: (d) base (<=50% by weight dry mass); (e) fire retardant (<=96% by weight dry mass); and (f) repellent agent (<2% by weight dry mass).

2. A formaldehyde-scavenging formulation according to claim 1, comprising base (<=50% by weight dry mass).

3. A formaldehyde-scavenging formulation according to claim 2, comprising base in the range 0.5-25% by weight dry mass.

4. A formaldehyde-scavenging formulation according to claim 1, additionally comprising at least one of: (A) dispersing agent; (B) viscosity modifier; and (C) polyphosphate sodium salts (NaPO.sub.3).sub.n.

5. A formaldehyde-scavenging formulation according to claim 1, additionally comprising pigment.

6. A formaldehyde-scavenging formulation according to claim 1, wherein the formaldehyde-scavenging formulation is an aqueous formulation.

7. A formaldehyde-scavenging formulation according to claim 1, wherein the fire retardant is selected from the group consisting of: aluminium trihydrate (ATH) and phosphorous nitrogen (PN) fire retardants

8. A formaldehyde-scavenging formulation according to claim 1, wherein: the formaldehyde scavenger is present in an amount of 1-50% by weight dry mass, and wherein the formaldehyde scavenger is polyvinylamine; the binder and/or crosslinker is present in an amount of <=20% by weight dry mass; the fire retardant is present in an amount of 50-96% by weight dry mass, and wherein the fire retardant is a phosphorous-nitrogen fire retardant; and the repellent agent is present in an amount of <2% by weight dry mass.

9. A formaldehyde-scavenging formulation according to claim 1, wherein: the formaldehyde scavenger is present in an amount of 1-50% by weight dry mass, and wherein the formaldehyde scavenger is polyvinylamine; the binder and/or crosslinker is present in an amount of <=20% by weight dry mass; and when present, the base is included in an amount of <=12.5% by weight dry mass; and when present, the fire retardant is included in an amount of 50-96% by weight dry mass, and is an aluminium trihydrate fire retardant.

10. A formaldehyde-scavenging formulation according to claim 1, wherein: the formaldehyde scavenger is polyvinylamine; the binder and/or crosslinker is present in an amount of <=50% by weight dry mass; and the base is present in an amount of <=25% by weight dry mass.

11. A formaldehyde-scavenging formulation according to claim 1, wherein the polyvinylamine (PVAm) has a weight average molecular weight (Mw) in the range 50,000-800,000 g/mol.

12. A non-woven veil coated with or containing a formaldehyde-scavenging formulation according to claim 1.

13. A non-woven veil coated with or containing an aminosilane.

14. A non-woven veil according to claim 12, wherein the veil is a glass fibre non-woven veil.

15. A construction product having a non-woven veil according to claim 12 on at least one surface.

16. A construction product according to claim 15, wherein the construction product is made of a wool selected from the group consisting of: glass wool, rock wool, stone wool and mineral wool.

17. A construction product according to claim 15, wherein the construction product is selected from the group consisting of: a ceiling tile, a wall panel, an insulation board, and a wood based panel.

18. A method of reducing formaldehyde emissions from a construction product, the method comprising the step of attaching a non-woven veil according to claim 12 to at least one outer surface of the construction product.

Description

DETAILED DESCRIPTION

[0130] The % by weight values used throughout the specification are based on the total dry weight.

[0131] In the following examples, formaldehyde-scavenging formulations and construction products according to the present invention show excellent results.

Example 1

[0132] In this example, a wood based panel (WBP) was used as a formaldehyde emission source. The rear side and edges of the panel were covered with a non-emissive aluminium tape (except for WBP+Recipe 1/25g 2 sides where the rear side was instead covered with a scavenging veil). The emitting surface was about 0.06 m{circumflex over ()}2 in a 51 L chamber. Formaldehyde concentrations (g/m{circumflex over ()}3) are given as estimation in the European standard room, considering Ceiling loading factor.

[0133] The Recipe 1 scavenger formulation used on the scavenging veils was:

TABLE-US-00001 Category Solids (%) Kg wet % dry anti-foam 0.5% 2.0 0.01% PN fire retardant 50.0% 149.9 65.59% scavenger (PVAm) 21.0% 149.9 27.55% repellent 30.0% 3.6 0.94% cross-linker 45.0% 15.0 5.90%

Samples:

[0134] Wood Based Panel (WBP): unfaced wood panel [0135] WBP+NS Veil: wood panel+1 non-scavenging veil applied on the surface [0136] WBP+Recipe 1/x12g: wood panel+1 scavenging veil (12 g/m.sup.2 add-on, meaning 3.3 g/m.sup.2 PVAm) [0137] WBP+Recipe 1/x25g: wood panel+1 scavenging veil (25.7 g/m.sup.2 add-on, meaning 7.1 g/m.sup.2 PVAm) [0138] WBP+Recipe 1/x25g 2 sides: wood panel+1 scavenging veil on the front side+1 scavenging veil on the rear side (two times 25.7 g/m.sup.2 add-on, meaning two times 7.1 g/m.sup.2 PVAm), emissive surface=0.12 m.sup.2.

Results:

[0139]

TABLE-US-00002 Formaldehyde Formaldehyde Area concentration Specific in Emission reference Rate SER room-Ceiling Days (g/m{circumflex over ()}2.h) (g/m{circumflex over ()}3) Wood based panel 2 160.4 128.3 (WBP) 7 152.8 122.2 WBP + NS Veil 2 161.1 128.9 7 169.1 135.3 WBP + Recipe 1/ 12 g 2 17.3 13.8 7 22.1 17.7 WBP + Recipe 1/ 25 g 2 10.4 8.3 7 13.4 10.7 WBP + Recipe 1/ 25 g 2 2.3 1.8 2 sides 7 8.0 6.4

[0140] The results show that each of the Recipe 1 WBP panels had significantly reduced formaldehyde emissions than the unfaced/untreated wood panel and the non-scavenging veil. In particular, the WBP+Recipe 1/x25g.sup.2 sides product achieved excellent results.

[0141] Further testing showed that the WBP+Recipe 1/x25g.sup.2 sides product had formaldehyde emissions of <10 ug/m{circumflex over ()}3 at 28 days.

Examples 2 and 3

[0142] In this example, a wood based panel was used as a formaldehyde emission source. The rear side and edges of the panel were covered with a non-emissive aluminium tape. The emitting surface was about 0.06 m{circumflex over ()}2 in a 51 L chamber. Formaldehyde concentrations (g/m{circumflex over ()}3) are given as estimation in the European standard room, considering Ceiling loading factor.

[0143] The Recipe 2 scavenger formulation (Example 2) used on the scavenging veils was:

TABLE-US-00003 Component Solids (%) Kg wet Kg dry anti-foam 0.5% 8.1 0.01% ATH fire retardant 68.0% 322.1 69.73% base 7.5% 450.9 10.77% scavenger (PVAm) 21.0% 161.0 10.77% acrylic binder 50.0% 49.9 7.95% repellent 30.0% 8.1 0.77%

[0144] The Recipe 3 scavenger formulation (Example 3) used on the scavenging veils was:

TABLE-US-00004 Component Solids (%) Kg wet Kg dry anti-foam 0.5% 8.1 0.01% ATH fire retardant 68.0% 324.7 70.28% base 7.5% 454.5 10.85% scavenger (PVAm) 21.0% 162.3 10.85% acrylic binder 50.0% 50.3 8.01%

Samples:

[0145] Wood Based Panel (WBP): unfaced wood panel [0146] WBP+A: wood panel+1 scavenging veil applied on the surface (Recipe 2, 45 g/m.sup.2 add-on, meaning 4.9 g/m.sup.2 PVAm) [0147] WBP+B: wood panel+1 scavenging veil applied on the surface (Recipe 3, 45 g/m.sup.2 add-on, meaning 4.9 g/m.sup.2 PVAm) [0148] WBP+NS Veil: wood panel+1 non-scavenging veil applied on the surface

Results:

[0149]

TABLE-US-00005 Formaldehyde concentration in reference SERA room- form Ceiling Days (g/m{circumflex over ()}2.h) (g/m{circumflex over ()}3) Ref-Wood based 7 138.1 110.5 panel (WBP) WBP + A 7 <QL <QL WBP + B 7 <QL <QL WBP + NS Veil 7 183.6 147 QL = quantification limit. For the reference room, the quantification limit is 0.3 g/m{circumflex over ()}3 (SERA form: approximately 0.4 g/m{circumflex over ()}2.h).

[0150] The results show that the panels with veils using the Recipe 2 and Recipe 3 formulations had very significantly reduced formaldehyde emissions compared to the unfaced/untreated wood panel and the non-scavenging veil (NS Veil).

[0151] In particular, since the formaldehyde emissions from the panels with veils using the Recipe 2 and Recipe 3 formulations could not be quantified, and since the rate of emissions decreases over time, it can be concluded that after 28 days the formaldehyde emissions at 28 days will be <10 ug/m{circumflex over ()}3.

Example 4

[0152] In this example, a formaldehyde scavenger formulation is as follows:

TABLE-US-00006 Component Solids (%) Kg wet Kg dry anti-foam 0.5% 5.6 0.01% ATH fire retardant 68.0% 658.8 89.25% base 7.5% 110.0 1.64% scavenger (PVAm) 21.0% 74.8 3.13% acrylic binder 50.0% 59.9 5.96%

[0153] With this, scavenger (i.e. the formulation) is added to a veil as follows:

TABLE-US-00007 Scavenger (g/m.sup.2) 4.38 Total add-on (including scavenger) (g/m.sup.2) 140

Example 5

[0154] In this example, a formaldehyde scavenger formulation is as follows:

TABLE-US-00008 Component Solids (%) Kg wet Kg dry anti-foam 0.5% 5.6 0.01% ATH fire retardant 68.0% 654.4 88.21% base 7.5% 109.3 1.62% scavenger (PVAm) 21.0% 74.4 3.10% acrylic binder 50.0% 59.5 5.90% repellent 30.0% 9.9 0.59% cross-linker 45.0% 6.5 0.58%

[0155] With this, scavenger (i.e. the formulation) is added to a veil as follows:

TABLE-US-00009 Scavenger (g/m.sup.2) 4.34 Total add-on (including scavenger) (g/m.sup.2) 140

Example 6

[0156] In this example, a formaldehyde scavenger formulation is as follows:

TABLE-US-00010 Component Solids (%) Kg wet Kg dry anti-foam 0.5% 12.7 0.02% ATH fire retardant 68.0% 580.8 93.41% base 7.5% 90.7 1.61% scavenger (PVAm) 21.0% 65.3 3.25% acrylic binder 50.0% 14.5 1.72%

[0157] With this, scavenger (i.e. the formulation) is added to a veil as follows:

TABLE-US-00011 Scavenger (g/m.sup.2) 3.67 Total add-on (including scavenger) (g/m.sup.2) 113

Example 7

[0158]

TABLE-US-00012 Component Solids (%) Kg wet Kg dry anti-foam 0.5% 67.3 0.21% base 7.5% 480.6 22.24% scavenger (PVAm) 21.0% 346.1 44.85% acrylic binder 50.0% 106.0 32.70%

[0159] With this, scavenger is added to a veil as follows:

TABLE-US-00013 Scav (g/m.sup.2) 4.48 Total add-on (including scavenger) (g/m.sup.2) 10

Example 8 (Reference Example)

[0160] In this example, a wood based panel was used as a formaldehyde emission source. The back (rear) side and edges of the panel were covered with a non-emissive aluminium tape. The emitting surface was about 0.06 m{circumflex over ()}2 in a 51 L chamber. Formaldehyde concentrations (g/m{circumflex over ()}3) are given as estimation in the European standard room, considering Ceiling loading factor.

[0161] The Recipe 4 scavenger formulation used on the scavenging veil was:

TABLE-US-00014 Component Solids (%) Kg wet Kg dry scavenger (aminosilane) 58.0% 100 100.000%

[0162] Water was added to arrive at a composition (i.e. formulation) suitable for the application method and needed dry add on.

Samples:

[0163] Wood based panel (WBP): unfaced wood panel [0164] WBP+Recipe 4: wood panel+1 scavenging veil (pure scavenger, 9 g/m{circumflex over ()}2 add-on, meaning 9 g/m{circumflex over ()}2 scavenger)

Results:

[0165]

TABLE-US-00015 Formaldehyde concentration in reference SERA room- form Ceiling Days (g/m{circumflex over ()}2.h) (g/m{circumflex over ()}3) Ref-Wood based 7 164.2 131.36 panel (WBP) WBP + Recipe 4 7 95 76

[0166] The results show that the panels with veils using the aminosilane achieved good results as compared to the reference WBP. This indicates that aminosilane is suitable for use as a formaldehyde scavenger.

Example 9

[0167] In this example, a formaldehyde scavenger formulation is as follows:

TABLE-US-00016 Component Solids (%) Kg wet Kg dry anti-foam 0.5% 26.0 0.01% ATH fire retardant 60.0% 3392.0 87.53% base 15.0% 350.0 2.26% scavenger (PVAm) 21.0% 340.0 3.07% acrylic binder 50.0% 272.0 5.85% repellent 30.0% 50.0 0.65% cross-linker 45.0% 33.0 0.64%

[0168] Improved formaldehyde scavenging results were obtained as compared to reference WBP.

[0169] Various modifications and variations to the described embodiments of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes of carrying out the invention which are obvious to those skilled in the art are intended to be covered by the present invention.