Construction materials containing surface modified fibers

• US 6,955,844 B2
• Filed: 05/27/2003
• Issued: 10/18/2005
• Est. Priority Date: 05/24/2002
• Status: Expired due to Term

• Current Assignee: Saint-Gobain Placo
• Original Assignee: Innovative Construction And Building Materials
• Inventors: Soane, David S., Saito, Ken, Pollock, Jacob Freas, Tagge, Christopher D., Torres, Lennard
• Primary Examiner(s): Dixon, Merrick
• Application Number:
  US10/446,889
• Publication Number:
  US 20030219580A1
• Time in Patent Office: 875 Days
• Field of Search: 428/36.4, 428/36.91, 428/53, 428/310.5, 428/339, 428/223, 428/294.7, 206/524.3
• US Class Current: 428/53
• CPC Class Codes: C04B 14/42 Glass
• CPC Class Codes: C04B 16/0691 Polyamides; Polyaramides
• CPC Class Codes: C04B 18/24 Vegetable refuse, e.g. rice husks, maize-ear refuse; Cellulosic materials, e.g. paper , cork
• CPC Class Codes: C04B 18/26 Wood, e.g. sawdust, wood shavings
• CPC Class Codes: C04B 18/28 Mineralising; Compositions therefor
• CPC Class Codes: C04B 20/1018 with organic materials pigments or dyes C04B20/1096
• CPC Class Codes: C04B 20/1037 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C04B 20/1051 Organo-metallic compounds; Organo-silicon compounds, e.g. bentone
• CPC Class Codes: C04B 2111/00612 as one or more layers of a layered structure
• CPC Class Codes: C04B 2111/27 Water resistance, i.e. waterproof or water-repellent materials
• CPC Class Codes: C04B 24/06 containing hydroxy groups
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 28/14 containing calcium sulfate cements gypsum-paper plates E04C
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete
• CPC Class Codes: Y10T 428/1372 Randomly noninterengaged or randomly contacting fibers, filaments, particles, or flakes
• CPC Class Codes: Y10T 428/1393 Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/17 Three or more coplanar interfitted sections with securing means
• CPC Class Codes: Y10T 428/249923 Including interlaminar mechanical fastener
• CPC Class Codes: Y10T 428/249924 Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
• CPC Class Codes: Y10T 428/249932 Fiber embedded in a layer derived from a water-settable material [e.g., cement, gypsum, etc.]
• CPC Class Codes: Y10T 428/249961 : With gradual property change within a component
• CPC Class Codes: Y10T 428/269 : including synthetic resin or polymer layer or component

Abstract

Construction materials containing surface modified reinforcements are used to fabricate composite structures. The composite structures comprise a matrix material and surface modified reinforcements, such as fibers and particulates. The surface modifier may be applied to a fiber surface using conventional sizing equipment and provides a durable film on the fiber. The surface modifier may be selected to have multifunctional properties, for example, increasing fiber pull-out strength, imparting bio-active properties, improving moisture resistance and other desirable properties to the composite structure.

Claims

1. A composite structure comprising:

a matrix material; and

surface-modified reinforcements distributed in at least a portion of the matrix material wherein the reinforcements are surface-modified by multifunctional molecules having a plurality of functions and one of the functions is to anchor the molecules to one of the reinforcement and the matrix.

2. The composite structure of claim 1, wherein another of the functions is to form crosslinks with other multifunctional molecules.

3. The composite structure of claim 1, wherein the matrix is of gypsum, and one of the functions is to anchor the molecules to the gypsum.

4. The composite structure of claim 1, wherein another of the functions is to repel water molecules.

5. The composite structure of claim 1, wherein another of the functions comprises bioactivity.

6. The composite structure of claim 1, wherein the reinforcements comprise wood fibers surface modified by a stearoyl chloride.

7. The composite structure of claim 1, wherein the reinforcements comprise glass fibers surface modified by a 3-aminopropyltriethoxysilane hydrolyzed under acidic conditions in the presence of the glass fibers.

8. The composite structure of claim 7, wherein the glass fibers are further modified with a polyisocyanate crosslinking the multifunctional molecules.

9. The composite structure of claim 8, wherein the crosslinking forms a network of crosslinked surface-modified glass fibers within the cementitious matrix material.

10. The composite structure of claim 3, wherein the reinforcements are of cellulose, and the reinforcements are surface-modified by a gypsophilic polymer, anchoring the reinforcements to the gypsum.

11. The composite of claim 10, wherein the multifunctional molecule is covalently attached to the reinforcements by partial reaction of a polyanhydride with the hydroxyl groups of the cellulose, and at least a portion of the remaining anhydride groups are hydrolyzed to carboxylic acids, and the carboxylic acid groups anchor to the gypsum crystals.

12. The composite structure of claim 1, wherein the reinforcements are of a synthetic and the multifunctional molecule is a hydrophilic polymer.

13. The composite structure of claim 12, wherein the matrix material comprises concrete.

14. The composite structure of claim 13, wherein the synthetic fibers are of nylon.

15. The composite structure of claim 13, wherein the hydrophilic polymer is one of a polycarboxylic acid and a sulfonate.

16. The composite structure of claim 15, wherein the synthetic fibers are partially reacted with a polyanhydride, and at least a portion of the unreacted anhydrides are hydrolyzed to carboxylate groups of the polycarboxylic acid forming poly(carboxylate) tendrils that anchor the fibers to the concrete during hydration of the concrete.

17. The composite structure of claim 16, wherein the polyanhydride is of poly(maleic anhydride).

18. The composite structure of claim 12, wherein the matrix material comprises gypsum.

19. The composite structure of claim 18, wherein the synthetic fibers are of nylon.

20. The composite structure of claim 18, wherein the synthetic fibers are surface modified by attachment of a gypsophilic polymer.

21. The composite structure of claim 20, wherein the gypsophilic polymer is one of a polycarboxylic acid and a sulfonate.

22. The composite structure of claim 21, wherein the gypsophilic polymer is of a polycarboxylic acid, and the synthetic fibers are partially reacted with a polyanhydride, and at least a portion of the unreacted anhydride groups are hydrolyzed to the carboxylic acid forming poly(carboxylate) tendrils that anchor the synthetic fibers to the gypsum.

23. The composite structure of claim 21, wherein the structure further comprises at least one surface layer and at least one inner layer adjacent to the surface layer, wherein the inner layer has a lower density of synthetic fibers than the surface layer.

24. The composite structure of claim 23 for use as a paperless wallboard, wherein the surface layer is thinner than the inner layer.

25. The composite structure of claim 4 for use as an exterior surface of a wallboard, wherein the reinforcements are of cellulose, and at least a portion of the hydroxyl groups of the cellulose react with a multifunctional molecule having anhydride groups to anchor the molecule to the reinforcements and a hydrophobic group to repel water.

26. The composite structure of claim 25, wherein the hydrophobic group is of a hydrocarbon or a fluorocarbon.

27. The composite structure of claim 1, wherein the reinforcements are of a synthetic, and the multifunctional molecules have reactive groups that partially react with the synthetic to attach the multifunctional molecules to the surface of the synthetic, and the unreacted reactive groups hydrolyze to form amine groups, and the amine groups react with a polymeric additive in the matrix to crosslink the multifunctional molecules to the polymeric additive.

28. The composite structure of claim 27, wherein the reinforcements are nylon fibers.

29. The composite structure of claim 28, wherein the multifunctional molecule is of a polyisocyanate.

30. The composite structure of claim 29, wherein the additive is of a polyurethane pre-polymer.

31. The composite structure of claim 30, wherein the polyurethane pre-polymer comprises a polyether terminated with diisocyanates.

32. The composite structure of claim 1, wherein the multifunctional molecules are comprised of a mixture of fluroaliphatic (meth)acrylate monomers, hydroxyalkyl (meth)acrylate monomers, stearyl (meth)acrylate monomers and chlorinated monomers.

33. The composite structure of claim 32, wherein the multifunctional molecules are polymerized and further comprise additional monomers with functional groups that react with one of a metal or metal salt to crosslink the surface modifier.

34. The composite structure of claim 32, wherein the multifunctional molecules are polymerized and further comprise additional monomers having a functional group selected from one of a carboxyl, carboxylate, sulfate, sulfonate, phosphate and phosphonate.

35. The composite structure of claim 34, wherein the additional monomers have a functional group selected from one of a carboxylate and a carboxyl.

36. The composite structure of claim 1, wherein the multifunctional molecules are polymerized, and the multifunctional molecules are comprised of co-polymers of stearyl (meth)acrylate and maleic anhydride.

37. The composite structure of claim 1, wherein the reinforcements are fibrous.

38. The composite structure of claim 37, wherein the reinforcements are incorporated into a fabric.

39. The composite structure of claim 38, wherein the multifunctional molecules are crosslinked after the reinforcements are incorporated into a fabric.

40. The composite structure of claim 38, wherein the multifunctional molecules are polymerized using a free radical initiator and a UV light source after the fabric is dry.

41. The composite structure of claim 5, wherein the multifunctional molecules comprise quarternized amine functional groups.

42. The composite structure of claim 41, wherein the quarternized amine functional groups comprise alkyl chains, each alkyl chain having 4 to 10 carbon atoms.

43. The composite structure of claim 4, wherein another of the functions comprises bioactivity.

44. The composite structure of claim 1, wherein the multifunctional molecules comprise a cellulose ether.

45. The composite structure of claim 44, wherein the cellulose ether is of a carboxymethyl cellulose.

46. The composite structure of claim 44, wherein the cellulose ether is of a methyl cellulose.

47. The composite structure of claim 44, wherein the cellulose ether is of a hydroxypropyl methyl cellulose.

48. The composite structure of claim 44, wherein the cellulose ether is of a hydroxyethyl methyl cellulose.

49. The composite structure of claim 44, wherein the multifunctional molecules further comprise a crosslinking agent.

50. The composite structure of claim 49, wherein the crosslinking agent comprises a polyurethane latex.

51. The composite structure of claim 49, wherein the crosslinking agent comprises an organic titanate.

52. The composite structure of claim 1, wherein the multifunctional molecules comprise polyvinyl pyrrolidone and polystyrene sulfonate.

53. The composite structure of claim 44, wherein the cellulose ether has a viscosity grade of at least 1000 cps, whereby the cellulose ether has limited mobility when mixed in an aqueous slurry.

54. The composite structure of claim 18, wherein the synthetic fibers are of polyester.

55. The composite structure of claim 54, wherein the synthetic fibers are surface modified by attachment of a gypsophilic polymer.