Plaster-based acoustic board

Abstract

A plaster-based board includes a core made of plaster positioned between two coating layers, in which a textile including glass fibers and an organic binder constitutes at least one of the coating layers and/or the textile is embedded in the plaster constituting the core. In the textile, the binder includes one or more organic polymers having a glass transition temperature which varies from −10 to +25° C., measured by differential scanning calorimetry according to the standard ISO 11357-1:2009.

Claims

1. A plaster-based board comprising a core made of plaster positioned between two coating layers, and a textile including glass fibers and an organic binder comprising at least one organic polymer exhibiting a glass transition temperature which varies from −10 to +25° C., said textile constituting one of the coating layers or the two coating layers and/or being embedded in the core made of plaster, wherein the textile includes at least 80% by weight of glass fibers.

2. The board as claimed in claim 1, wherein the textile is a nonwoven or a fabric.

3. The board as claimed in claim 1, wherein the glass fibers are individual glass filaments having a diameter which varies from 5 to 30 μm, or strands comprising a plurality of the glass filaments or an assemblage of several base strands.

4. The board as claimed in claim 1, wherein the textile includes up to 20% by weight of fibers different in chemical nature from the glass fibers.

5. The board as claimed in claim 4, wherein the fibers different in chemical nature from the glass fibers are organic natural or synthetic fibers.

6. The board as claimed in claim 4, wherein the fibers different in chemical nature from the glass fibers are polymer fibers, mineral fibers, carbon fibers or metal fibers.

7. The board as claimed in claim 1, wherein the organic polymer is chosen from copolymers of an olefin and of vinyl acetate, copolymers of vinyl acetate and of (meth)acrylic acid or of (meth)acrylate, copolymers of (meth)acrylate and of a monomer other than vinyl acetate, homopolymers of (meth)acrylic acid or of acrylate, terpolymers of vinyl acetate, of an olefin and of a vinyl ester monomer, acrylonitrile polymers, and terpolymers of acrylonitrile, of butadiene and of styrene.

8. The board as claimed in claim 7, wherein the organic polymer is a copolymer of butyl acrylate and of styrene.

9. The board as claimed in claim 7, wherein the olefin is ethylene, propylene, butylene or isobutylene, wherein the monomer other than vinyl acetate is styrene, and wherein the acrylonitrile polymers are copolymers of acrylonitrile and of (meth)acrylate.

10. The board as claimed in claim 1, wherein the organic polymer has a glass transition temperature (Tg) which varies from 0 to +10° C.

11. The board as claimed in claim 1, wherein the textile contains from 10 to 50% by weight of organic binder, calculated on the basis of solid matter.

12. The board as claimed in claim 11, wherein the textile contains from 15 to 25% by weight of organic binder, calculated on the basis of the solid matter.

13. The board as claimed in claim 1, wherein the textile exhibits a weight per unit area which varies from 10 to 800 g/m.sup.2.

14. The board as claimed in claim 13, wherein the textile exhibits a weight per unit area which varies from 30 to 500 g/m.sup.2.

15. The board as claimed in claim 14, wherein the textile exhibits a weight per unit area which varies from 35 to 120 g/m.sup.2.

16. The board as claimed in claim 1, wherein the board has a thickness which varies from 6 to 25 millimeters.

17. The board as claimed in claim 16, wherein the board has a thickness of the order of 12.5 millimeters.

18. The board as claimed in claim 1, wherein the textile includes at least 90% by weight of glass fibers.

19. The board as claimed in claim 1, wherein said textile is made of a mat including said glass fibers and said organic binder, said organic binder penetrating through a thickness of said mat to form said textile.

20. The board as claimed in claim 19, wherein said textile consists of said mat of said glass fibers and said organic binder.

21. The board as claimed in claim 1, wherein said organic binder is the only binder that is used to form said textile.

22. A method comprising improving the acoustic insulation in a building with a plaster-based board as claimed in claim 1.

23. A plaster-based board comprising a core made of plaster positioned between two coating layers, and a textile including glass fibers and an organic binder comprising at least one organic polymer exhibiting a glass transition temperature which varies from −10 to +25° C., said textile constituting one of the coating layers or the two coating layers and/or being embedded in the core made of plaster, wherein the organic polymer is an acrylonitrile polymer that is a copolymer of acrylonitrile and of methyl methacrylate.

24. A method comprising improving the acoustic properties of a plaster-based board comprising a core made of plaster positioned between two coating layers with a textile, including glass fibers and an organic binder comprising at least one organic polymer exhibiting a glass transition temperature which varies from −10 to +25° C., in which said textile constitutes one of the coating layers or the two coating layers and/or is embedded in the core made of plaster, wherein the textile includes at least 80% by weight of glass fibers.

Description

EXAMPLES 1 TO 10

(1) Plaster-based boards comprising one or two textiles in accordance with the invention are manufactured under the following conditions:

(2) a) a plaster composition is prepared by introducing 1000 g of calcium sulfate hemihydrate, 5 g of starch, 0.1 g of a setting accelerator (fine gypsum treated with sucrose), 0.05 g of a setting retarder (Plast Retard L, sold by Sicit 2000) and 750 g of water into a mixer provided with a three-bladed stirrer at the speed of 650 rpm for 15 seconds and then 1850 rpm for 45 seconds.

(3) b) a foam is prepared by introducing 138.5 g of water and 1.4 g of foaming agent (Milifoam®, sold by Huntsman) into a mixer provided with a three-bladed stirrer at the speed of 3300 rpm for 1 minute.

(4) c) the plaster composition obtained in stage a) and 30 g of foam obtained in stage b) are introduced into a mixer provided with a planetary paddle operating at the speed of 250 rpm for 50 seconds, in order to obtain a paste.

(5) d) the paste is poured into a brass mold comprising 4 parallelepipedal cavities (length: 300 mm; width: 30 mm; depth: 13 mm), the internal walls of which are coated with a layer of oil and the bottom of which is coated with a sheet of cardboard or of the textile according to the invention.

(6) When a textile in accordance with the invention is incorporated in the paste, the paste is first poured into the mold over a thickness of 6 mm, then the textile, cut to the size of the mold, is deposited and the mold is filled with the paste.

(7) A sheet of cardboard or a textile, having the size of the mold, is deposited over the paste and the mold is closed with a board on which two weights each of 5 kg are placed.

(8) The boards are removed from the mold after 20 minutes, left in the open air for 10 minutes, then placed in a first drying oven at 180° C. for 35 minutes and in a second drying oven at 100° C. for 25 minutes. The boards are stored in a dry chamber at 40° C.

(9) In the examples, use is made of: a nonwoven (1) consisting of filaments of E glass (diameter: 10 μm; length: 10 mm) obtained by the wet route and bonded by an aqueous binder containing 50% by weight of a copolymer of butyl acrylate and of styrene (sold under the reference Acronal S 537 S by BASF; Tg=−5° C.). The nonwoven contains 15% by weight of binder, calculated on the basis of the solid matter, and exhibits a weight per unit area equal to 50 g/m.sup.2, a nonwoven (2) consisting of continuous filaments of C glass (diameter 5-13 μm) obtained by the dry route and bonded by an aqueous binder containing 50% by weight of a copolymer of butyl acrylate and of styrene (sold under the reference Acronal S 537 S by BASF; Tg=−5° C.). The nonwoven contains 20% by weight of binder, calculated on the basis of the solid matter, and exhibits a weight per unit area equal to 80 g/m.sup.2, a nonwoven (3) consisting of filaments of E glass (diameter: 10 μm; length: 10 mm) obtained by the wet route and bonded by an aqueous binder containing 47% by weight of a copolymer of butadiene and of styrene (sold under the reference Litex S 9076 by Synthomer; Tg=−44° C.). The nonwoven contains 15% by weight of binder, calculated on the basis of the solid matter, and exhibits a weight per unit area equal to 50 g/m.sup.2, a nonwoven (4) consisting of filaments of E glass (diameter: 10 μm; length: 10 mm) obtained by the wet route and bonded by an aqueous binder containing 50% by weight of a copolymer of butadiene and of styrene (sold under the reference Lipaton SB 5841 by Synthomer; Tg=−5° C.). The nonwoven contains 15% by weight of binder, calculated on the basis of the solid matter, and exhibits a weight per unit area equal to 50 g/m.sup.2, a nonwoven (5) consisting of filaments of E glass (diameter: 10 μm; length: 10 mm) obtained by the wet route and bonded by an aqueous binder containing 50% by weight of a copolymer of butadiene and of styrene (sold under the reference Synthomer VL10946 by Synthomer; Tg=−50° C.). The nonwoven contains 15% by weight of binder, calculated on the basis of the solid matter, and exhibits a weight per unit area equal to 50 g/m.sup.2, a nonwoven (6) consisting of filaments of E glass (diameter: 10 μm; length: 10 mm) obtained by the wet route and bonded by an aqueous binder containing 25% by weight of a copolymer of methacrylic acid and of acrylic ester (sold under the reference Rohagit sd 40 by Synthomer; Tg=100° C.). The nonwoven contains 15% by weight of binder, calculated on the basis of the solid matter, and exhibits a weight per unit area equal to 50 g/m.sup.2, and a sheet of cardboard (V5 sold by Saint-Regis).

(10) Example 1 comprises a nonwoven (1) on one face of the board and a sheet of cardboard on the other face.

(11) Example 2 comprises a nonwoven (1) on each face of the board.

(12) Example 3 comprises a nonwoven (2) on one face of the board and a sheet of cardboard on the other face.

(13) Example 4 comprises a nonwoven (2) on each face of the board.

(14) Example 5 comprises a nonwoven in the core made of plaster, at midheight of the thickness, and a cardboard on each face of the board.

(15) Example 6 comprises a nonwoven (4) on each face of the board.

(16) Example 7 comprises a nonwoven (5) on each face of the board.

(17) Comparative example 8 comprises a nonwoven (6) on each face of the board.

(18) Comparative example 9 comprises a nonwoven (7) on each face of the board.

(19) By way of reference, a board comprising two sheets of cardboard and not including any textile in accordance with the invention in the core made of plaster was prepared under the same conditions (reference example 10).

(20) The acoustic performance levels of the boards are evaluated by measuring their mechanical impedance MIM (Measurement of Mechanical Impedance) under the conditions of the standard ISO 16940:2008(E). The dynamic Young's modulus (in GN/m.sup.2) and the loss factor η (in %) are calculated from the curve of the acceleration frequency (dB) as a function of the frequency (Hz). The acoustic gain with respect to the board of (comparative) example 6 is also calculated.

(21) The results are given in the following table.

(22) TABLE-US-00001 Dynamic Weight per Young's Loss Acoustic unit area modulus factor gain (kg/m.sup.2) (GN/m.sup.2) (%) (%) Ex. 1 8.7 2.33 1.78 24 Ex. 2 8.4 1.79 1.10 41 Ex. 3 8.9 2.73 0.48 10 Ex. 4 9.0 2.64 0.69 13 Ex. 5 9.3 1.62 9.95 47 Ex. 6 9.1 1.75 3.24 28 Ex. 7 9.1 1.52 4.52 38 Ex. 8 8.9 2.36 0.46 3.3 (Comp) Ex. 9 9.0 2.89 0.38 −18 (Comp) Ex. 10 9.30 3.05 0.15 — (Ref)