RESIN BINDER COMPOSITION AND FILTER MEDIUM COMPRISING THE RESIN BINDER COMPOSITION

Abstract

The present invention relates to a resin binder composition, a filter medium comprising the resin binder composition as well as related methods and uses.

Claims

1. A resin binder composition comprising: i) at least one resin P containing in the form of polymerized units at least one ethylenically unsaturated monomer M, wherein the monomer M optionally comprises further functional groups, ii) at least one aminoplast resin and/or at least one phenoplast resin, iii) at least one urea derivate and/or urea, and iv) optionally at least one additive.

2. The resin binder composition according to claim 1, wherein the ethylenically unsaturated monomer M is selected from the group consisting of acrylic acid, methacrylic acid or the salts thereof, acrylamide or mixtures thereof.

3. The resin binder composition according to claim 1 or 2, comprising: i) 8 to 98.5% by weight of at least one resin P, ii) 1 to 62% by weight of at least one aminoplast resin and/or at least one phenoplast resin, and iii) 0.5 to 30% by weight of at least one urea derivative and/or urea, based on the total weight of the dry solid content of the resin binder composition.

4. The resin binder composition according to any of the claims 1 to 3, wherein the at least one aminoplast resin is selected from the group consisting of urea formaldehyde resins, melamine formaldehyde resins, melamine polyesters and melamine phenol formaldehyde resins.

5. The resin binder composition according to any of the claims 1 to 4, wherein the at least one phenoplast resin is selected from the group consisting of resole resins and novolac resins.

6. The resin binder composition according to any of the claims 1 to 5, wherein the at least one ethylenically unsaturated monomer M is acrylic acid.

7. The resin binder composition according to any one of claims 1 to 6, wherein the at least one additive comprises a flame retardant.

8. A filter medium comprising: a) at least one layer L, and b) the resin binder composition according to any one of the claims 1 to 7.

9. The filter medium according to claim 8 comprising: a) at least one layer L comprising: a1) 10 to 100% by weight of natural fibers, a2) 0 to 90% by weight of synthetic and/or inorganic fibers, based on the total weight of the fibers in the layer L, and b) 5 to 40% by weight of the resin binder composition, based on the total weight of the at least one layer L.

10. The filter medium according to any of the claims 7 to 9, wherein the amount of formaldehyde released is less than 5 g/kg as measured according to AATCC test method 112-2014.

11. The filter medium according to any of the claims 7 to 10, wherein the synthetic fibers are polyester fibers.

12. The filter medium according to any of the claims 7 to 11, wherein the at least one layer L is a wet-laid layer.

13. The filter medium according to any one of claims 7 to 12, wherein the at least one layer L has an full-life efficiency equal to or higher than 90.00%.

14. A filter element comprising the filter medium according to any of the claims 7 to 13.

15. Use of the filter medium according to any one of the claims 7 to 13 for air filtration.

Description

EXAMPLE 1

[0236] A nonwoven layer was produced using a wet laid process. The layer comprises 80% by weight of cellulose fibers and 20% by weight of PBT fibers, based on the total weight of the fibers in the layer. This layer was then impregnated with a resin binder composition comprising 47% by weight of acrylic resin, 12% by weight of an aminoplast, 5% by weight of urea and 36% by weight of at least one additive (wt % is based on the total weight of the dry solid content of the resin binder composition. [0237] Thickness: 0.35 mm [0238] Air permeability: 282 L/m.sup.2 s [0239] Basis weight: 123 g/m.sup.2 [0240] Many pores: 53 m [0241] Max. pore: 73 [0242] Full-life efficiency: 99.8% [0243] Dust holding capacity: 103 g/m.sup.2 [0244] Bursting strength (dry): 306 kPa [0245] Bursting strength (wet) (10 min/dest. water): 271 kPa [0246] Width related bending stiffness (15 MD): 320 cNmm (band size: 15 mm) [0247] Amount of formaldehyde released: 4.5 g/kg [0248] Redrying: 5 minutes [0249] Smolder Test: S1

Comparative Example 1

[0250] Same process as above and same fiber composition. Saturation: 47% by weight acrylic resin, 12% by weight of an aminoplast and 41% by weight of at least one additive (wt % is based on the total weight of the dry solid content of the resin binder composition). [0251] Thickness: 0.33 mm [0252] Air permeability: 295 L/m.sup.2 s [0253] Basis weight: 125 g/m.sup.2 [0254] Many pores: 55 m [0255] Max. pore: 71 [0256] Full-life efficiency: 99.8% [0257] Dust holding capacity: 104 g/m.sup.2 [0258] Bursting strength (dry): 305 kPa [0259] Bursting strength (wet) (10 min/dest. water): 290 kPa [0260] Width related bending stiffness (15 MD): 326 cNmm (band size: 15 mm) [0261] Amount of formaldehyde released: 10.0 g/kg [0262] Redrying: 7 minutes

EXAMPLE 2

[0263] A nonwoven layer was produced using a wet laid process. The layer comprises 100% by weight of cellulose fibers, based on the total weight of the fibers in the layer. This layer was then impregnated with a resin binder composition comprising 67% by weight of acrylic resin, 4% by weight of aminoplast, 10% by weight of urea and 19% by weight of at least one additive (wt % is based on the total weight of the dry solid content of the resin binder composition). [0264] Thickness: 0.32 mm [0265] Air permeability: 119 L/m.sup.2 s [0266] Basis weight: 118 g/m.sup.2 [0267] Many pores: 30 m [0268] Max. pore: 42 m [0269] Full-life efficiency: 99.9% [0270] Dust holding capacity: 97 g/m.sup.2 [0271] Bursting strength (dry): 390 kPa [0272] Bursting strength (wet): 103 kPa [0273] Smolder Test: S1 [0274] Amount of formaldehyde released: 0.7 g/kg [0275] Redrying after 7 minutes [0276] Width related bending stiffness (15 MD): 244 cNmm (band size: 15 mm)