Paintable cloth based on plant fibers

Abstract

A paintable cloth includes a woven fabric including plant fibers, especially flax, jute, ramie and/or sisal fibers, the woven fabric additionally being coated with a finish.

Claims

1. A paintable cloth comprising a woven fabric consisting of plant fibers, said woven fabric additionally being coated with a finish, wherein the finish comprises the constituents below, in the following proportions expressed as weight percentages of solids: 5% to 75% of a starchy compound, 20% 55% of at least one acrylic polymer, and 1.5% to 5% of a crosslinking agent.

2. The paintable cloth as claimed in claim 1, wherein the plant fibers are in the form of a yarn.

3. The paintable cloth as claimed in claim 1, wherein the plant fibers are flax, jute, ramie and/or sisal fibers.

4. The paintable cloth as claimed in claim 1, wherein the woven fabric comprises, as warp, a twisted yarn and, as weft, a non-twisted yarn.

5. The paintable cloth as claimed in claim 4, wherein the non-twisted yarn is a volumized yarn.

6. The paintable cloth as claimed in claim 1, wherein a linear density of warp and weft yarns of the woven fabric varies from 50 to 500 tex.

7. The paintable cloth as claimed in claim 1, wherein the woven fabric has a basis weight that varies from 30 to 1000 g/m.sup.2.

8. The paintable cloth as claimed in claim 1, wherein the finish is present on both sides of the paintable cloth.

9. The paintable cloth as claimed in claim 1, wherein the starchy compound consists of more than 50% by weight of a starch that is soluble in water at a temperature of from 20 C. to 25 C.

10. The paintable cloth as claimed in claim 1, wherein the acrylic polymer is a homopolymer or copolymer of (meth)acrylic acid or an alkyl acrylate.

11. The paintable cloth as claimed in claim 1, wherein the finish contains, as a weight percentages of solids: 30% to 50% of starch, 30% to 50% of at least one styrene/(meth)acrylic acid copolymer, 2% to 5% of ammonium zirconium carbonate, 0.1% to 5% of a foaming agent, 0.1% to 5% of a foam stabilizer, and 0 to 25% of a mineral filler.

12. The paintable cloth as claimed in claim 1, wherein the finish contains, as a weight percentages of solids: 5% to 65% of starch, 15% to 55% of at least one acrylic polymer, 1.5% to 5% of ammonium zirconium carbonate, 0 to 4% of a softener, 0 to 10% of a thickener, and 0 to 20% of a mineral filler.

13. The paintable cloth as claimed in claim 1, further comprising a supplementary layer composed of a water-reactivatable adhesive on its underside.

14. The paintable cloth as claimed in claim 3, wherein the plant fibers are flax and/or jute fibers.

15. The paintable cloth as claimed in claim 14, wherein the plant fibers are flax fibers.

16. The paintable cloth as claimed in claim 6, wherein the linear density of the warp and weft yarns varies from 100 to 350 tex.

17. The paintable cloth as claimed in claim 7, wherein the woven fabric has a basis weight that varies from 50 to 300 g/m.sup.2.

18. The paintable cloth as claimed in claim 17, wherein the woven fabric has a basis weight that varies from 75 to 200 g/m.sup.2.

19. The paintable cloth as claimed in claim 1, wherein the crosslinking agent is an ammonium zirconium carbonate.

20. The paintable cloth as claimed in claim 10, wherein the acrylic polymer is a styrene/(meth)acrylic acid or alkyl acrylate/acrylonitrile copolymer.

Description

EXAMPLE 1

(1) This example illustrates the manufacture of a paintable cloth on a pilot line.

(2) An aqueous finishing composition is prepared that contains the following constituents, in weight percentages:

(3) TABLE-US-00001 Styrene/acrylic copolymer.sup.1 11.3 Modified potato starch.sup.2 5.4 Ammonium zirconium carbonate.sup.3 2.0 Ammonium stearate.sup.4 0.7 Amine oxide.sup.5 0.3 Titanium oxide.sup.6 0.3 Water 80.0

(4) The finishing composition is used to coat a woven flax fabric having a width equal to 30 cm and a basis weight equal to 80 g/m.sup.2 comprising, as warp, a (twisted) flax textile yarn having a linear density equal to 125 tex with a warp density of 3.1 yarns per cm and, as weft, a non-twisted flax yarn having a linear density of 200 tex with a weft density of 1.8 yarns per cm.

(5) The finishing composition is applied using a pad-coating machine.

(6) The woven flax fabric then passes into an oven (230 C.; length: 5 m) speed 0.5 m/min. On leaving the oven the woven fabric has a basis weight equal to 109 g/m.sup.2.

(7) By way of comparison, the finishing composition is applied under the same conditions as above to a woven glass fabric having a basis weight equal to 88.0 g/m.sup.2 consisting, as warp, of (twisted) textile yarns made of glass having a linear density equal to 140 tex with a warp density of 3.0 yarns per cm and, as weft, (non-twisted) glass yarns having a linear density of 220 tex with a weft density of 1.7 yarns per cm. The final woven glass fabric has a basis weight equal to 121.0 g/m.sup.2.

(8) The measurements of the tensile strength of the woven fabrics made of flax (example 1) and of glass (comparative example 1) are given in table 1.

EXAMPLE 2

(9) An aqueous finishing composition is prepared that contains the following constituents, in weight percentages:

(10) TABLE-US-00002 Styrene/butyl acrylate copolymer.sup.7 5.9 Acrylic ester/acrylonitrile copolymer.sup.8 10.9 Modified potato starch.sup.2 26.1 Wheat starch 1.0 Ammonium zirconium carbonate.sup.3 3.4 Calcium carbonate.sup.9 2.5 Silicone-based softener .sup.10 0.3 Water 49.9

(11) The finishing composition is used to coat a woven flax fabric having a basis weight equal to 160 g/m.sup.2 comprising, as warp, a (twisted) flax textile yarn having a linear density equal to 200 tex with a warp density of 3.1 yarns per cm and, as weft, a non-twisted flax yarn having a linear density of 300 tex with a weft density of 1.8 yarns per cm.

(12) The finishing composition is applied according to a dip-coating process which consists in immersing the woven fabric in a tank containing said finishing composition then in depositing the woven fabric on a suction belt so as to eliminate the excess finish. The dip-coating application is equivalent to the screen-to-screen application mentioned above.

(13) The woven flax fabric is then placed in an oven at 210 C. for 4 minutes. On leaving the oven the woven fabric has a basis weight equal to 229 g/m.sup.2.

(14) As a comparative example, the finishing composition is applied under the same conditions as above to a woven glass fabric having a basis weight equal to 146.2 g/m.sup.2 consisting, as warp, of (twisted) textile yarns made of glass having a linear density equal to 280 tex with a warp density of 1.5 yarns per cm and, as weft, (non-twisted) glass yarns having a linear density of 550 tex with a weft density of 1.9 yarns per cm. The final woven glass fabric has a basis weight equal to 195.0 g/m.sup.2.

(15) Still for comparison purposes, the tensile strength of two textured nonwoven paintable coverings was measured: one covering based on cellulose fibers (Vlisfaser 707 sold by Erfurt; basis weight: 165 g/m.sup.2; comparative example 3) and an expanded vinyl paper (Superfresco sold by Graham & Brown; basis weight: 200 g/m.sup.2; comparative example 4).

(16) Table 1 collates the measurements of the tensile strength of the woven fabrics made of flax (example 2) and of glass (comparative example 2) and also of the nonwoven paintable coverings (comparative examples 3 and 4).

(17) The paintable cloths made of flax according to the invention (examples 1 and 2) have a tensile strength, after manufacture and after aging, which is always greater than that of the nonwoven coverings (comparative examples 3 and 4).

(18) The paintable cloth from example 2 has a tensile strength before and after ageing which is greater than that of the paintable cloth made of glass (comparative example 2). Without wanting to be tied to any one scientific explanation, the inventors believe that this is due to a better impregnation of the flax yarns by the finish compared to the glass yarns (in particular of the weft yarns which are not twisted) and to a better compatibility of the finish with the cellulose constituting the flax yarns. .sup.1: Acronal S589 sold by the company BASF; 52% solids .sup.2: Amitrolit 8900 sold by the company Agrana; 90% solids .sup.3: AZC sold by the company Auer Remy; 20% solids .sup.4: ammonium stearate sold by the company Peer Greven; 30% solids .sup.5: Genaminox sold by the company Clariant; liquid with 100% active material .sup.6: XWO5 sold by the company Ecofix AB; 59% solids .sup.7: Acronal S996 sold by the company BASF; 46% solids .sup.8: Acronal LN579S sold by the company BASF; 50% solids .sup.9: Hydrocarb 90-GU sold by the company Omya; 78% solids .sup.10: Cepolsoft SIL sold by the company Prochimica; 16% solids

(19) TABLE-US-00003 TABLE 1 Tensile strength Comp. Comp. Comp. Comp. (N/5 cm) Ex. 1 ex. 1 Ex. 2 ex. 2 ex. 3 ex. 4 after manufacture (TSm) machine direction 265.8 647.1 514.0 573.1 208.9 241.4 cross direction 295.8 335.5 896.7 509.6 233.6 141.6 after aging (TSa) machine direction 233.7 389.8 475.2 318.4 75.8 54.2