FORMALDEHYDE FREE SAFE TO USE BINDER FORMULATION FOR WOVEN, NONWOVEN AND GRANULAR MATERIALS

Abstract

Binder compositions that are formaldehyde free and include a latex emulsion, an epoxysilane, an epoxy dispersion, a polyol or a latex emulsion, a styrenic copolymer having carboxylic acid functionality, an epoxysilane or an epoxy dispersion or a mixture of both, a polyol and, optionally, an additive, wherein the composition does not comprise formaldehyde are described.

Claims

1-38. (canceled)

39. A formaldehyde free composition comprising: a latex emulsion, wherein the latex emulsion consists of a copolymerization product of one or more of vinylaromatic monomer(s), acrylic acid, methacrylic acid, acrylate monomer(s), methacrylate monomer(s), acrylonitrile, vinyl acetate, ethylene, propylene, butadiene, acrylamide, methacrylamide, hydroxyalkyl acrylate(s), itaconate(s), fumarate(s), or hydroxyalkyl methacrylate(s) or mixtures thereof; an epoxysilane or an epoxy dispersion or a mixture of both; a water soluble polycarboxylic acid; a polyol; and, optionally, an additive, wherein the composition does not comprise formaldehyde.

40. The formaldehyde free composition of claim 39, wherein the epoxysilane comprises: ##STR00004## wherein: R is (CH.sub.2)m, where m has a value of 0 to 6; R.sup.2 is a C.sub.1-C.sub.10 alkyl, optionally substituted with a C.sub.1-C.sub.10 alkoxy, or a C.sub.6-C.sub.10 aryl or a C.sub.7-C.sub.10 aralkyl group; R.sup.3 is a C.sub.2-C.sub.6 alkyl, optionally substituted with a C.sub.1-C.sub.10 alkoxy, or a C.sub.6 -C.sub.10 aryl or a C.sub.7-C.sub.10 aralkyl group; R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are individually each hydrogen or a C.sup.1-C.sup.6 alkyl group; R.sup.8 is a C.sub.1-C.sub.4 alkylene group or a C.sub.7-C.sub.10 aralkylene or a C.sub.6-C.sub.10 arylene group; R.sup.9 is RSi(R.sub.n.sup.2)(OR.sup.3).sub.3?n; n is 0, 1 or 2; c, d and e are each independently 0 or 1; and f is 0, 1 or 2.

41. The formaldehyde free composition of claim 40, wherein the epoxysilane comprises a glycidoxy silane, a beta-(3,4-epoxycyclohexyl)-ethyl alkoxysilane or an epoxidized bisphenol A novolac resin.

42. The formaldehyde free composition of claim 41, wherein the glycidoxy silane comprises one or more of gamma-glycidoxypropyl trimethoxysilane, gamma-glycidoxypropyl triethoxysilane, gamma-glycidoxypropyl methyldimethoxysilane, or gamma-glycidoxypropyl methyldiethoxysilane.

43. The formaldehyde free composition of claim 40, wherein the epoxysilane comprises beta-(3,4-epoxycyclohexyl)-ethyl trimethoxysilane, beta-(3,4-epoxycyclohexyl)-ethyl methyl dimethoxysilane, beta-(3,4-epoxycyclohexyl)-ethyl methyl diethoxysilane, or beta-(3,4-epoxycyclohexyl)-ethyl triethoxysilane.

44. The formaldehyde free composition of claim 39, wherein the epoxy dispersion comprises an epoxidized bisphenol A novolac resin.

45. The formaldehyde free composition of claim 39, wherein the water soluble polycarboxylic acid comprises at least 2 carboxylic acid groups.

46. The formaldehyde free composition of claim 39, wherein the polyol is starch.

47. The formaldehyde free composition of claim 39, further comprising an additive.

48. The formaldehyde free composition of claim 39, wherein the wt % of the latex is from about 55 wt % to about 95 wt %.

49. The formaldehyde free composition of claim 39, wherein the wt % of the polyol is from about 2 wt % to about 50 wt %.

50. The formaldehyde free composition of claim 39, wherein the wt % of the epoxy silane and/or the epoxy dispersion is from about 1 wt % to about 10 wt % in total.

51. The formaldehyde free composition of claim 39, wherein the wt % of the optional additive is from about 1 wt % to about 5 wt %.

52. The formaldehyde free composition of claim 48, wherein the latex is a styrene butadiene latex.

53. The formaldehyde free composition of claim 52, wherein the wt % of the polyol is from about 2 wt % to about 50 wt %.

54. The formaldehyde free composition of claim 52, wherein the wt % of the epoxy silane and/or the epoxy dispersion is from about 1 wt % to about 10 wt % in total.

55. The formaldehyde free composition of claim 52, wherein the wt % of the optional additive is from about 1 wt % to about 5 wt %.

Description

EXAMPLES

Sample Preparation and Test Conditions

[0181] Solids content of all the formulations in Table 1 are 12 to 14%adjusted to obtain a final dry binder pick up of 20 to 21% on final dry weight.

[0182] The formulation was prepared a room temperature. Starch was first dissolved in water and heated until dissolution. The epoxysilane is mixed with the latex. The latex formulated with the epoxysilane, starch and the water soluble polycarboxylic acid polymer (SMA) were then mixed at room temperature. Suitable epoxide or epoxy resin was then added to the mixture at room temperature and stirred. The resultant mixture was stable at room temperature for at least 3 hours after preparation and could be considered shelf stable.

[0183] In some examples the epoxysilane is mixed with the latex. The latex formulated with the epoxysilane, starch and the water soluble polycarboxylic acid polymer (SMA) were then mixed at room temperature.

[0184] In other examples, the soluble polycarboxylic acid polymer (SMA) and the epoxysilane were mixed into the latex in a stable ready to use formulated latex. The binder formulation was prepared by addition of the starch and water to this ready to use latex.

[0185] Suitable epoxide or epoxy resin was then added to the mixture at room temperature and stirred. The resultant mixture was stable at room temperature for at least 3 hours after preparation and could be considered shelf stable.

[0186] Nonwoven Base A: Polyester spunbond nonwoven base of grammage of 160 gsm without reinforcing threads, sheets of 45 cm (in MD)?27 cm (in CD).

[0187] The polyester spunbond nonwoven bases A and B were soaked in the formulation for 2 minutes at ambient conditions.

[0188] Excess of binder formulation was removed by passing the wetted nonwoven thorough a Lab Mathis foulard nip (pressure=2.5 bars) to provide a treated nonwoven

[0189] The treated nonwoven was then dried in a Mathis Oven for 8 minutes at 180? C.

Sample Testing

[0190] Thermal dimensional stability (TDS) is a measurement of the deformation (elongation and shrinkage) of a sample of 10 cm?25 cm in a creep test. TDS is important, for example, for the non-woven used for bituminized water proofing membranes. Lower TDS values are optimal.

[0191] The TDS creep test conditions were adjusted to the different nonwoven bases, in order to get representative data, able to properly discriminate the effect of the binder formulation.

[0192] For nonwoven base A: a load of 8 kg/10 cm was applied in the machine direction during 15 minutes at 200? C.; i.e. the samples are 10 cm (in CD cross direction)?25 cm (in MD machine direction).

[0193] For nonwoven base B: In the first series of measurements a load of 8 kg/10 cm is applied in machine direction during 15 minutes at 200? C.; i.e. the samples are 10 cm (in CD cross direction)?25 cm (in MD machine direction). In a second serices of measurements, a load of 4 kg/10 cm is applied in cross direction direction during 15 minutes at 200? C.; i.e. the samples are 10 cm (MD machine direction)?25 cm (in CD cross direction). This second series of measurements allows for determination of the contribution of the binder formulation, independently of the reinforcing effect of the glass fiber threads.

[0194] For nonwoven base C: a load of 4 kg/10 cm is applied in cross direction during 10 minutes at 200? C.; i.e. the samples are 10 cm (MD machine direction)?25 cm (in CD cross direction). This condition allows determination of the contribution of the binder formulation, independently of the reinforcing effect of the glass fiber threads.

[0195] Load and elongation at break, are measured according to DIN EN 29073 (ISO09073-3).

TABLE-US-00001 TABLE 1 Spunbond Base A Thermal dimensional stability creep test, (load: 8 kg/10 cm, 200? C., 15 min) Styrene (the lower the better) Melamine maleic Epoxy Load % % shrinkage Latex formaldehyde acid Epoxysilane resin at Elongation elongation (perpendicular XZ resin copolymer (CoatOsil dispersion break at break (in load to load 97223 Starch (Saduren163) (Xiran 40005) 2287) (Epirez) (N/5 cm) (%) direction) direction) R1 90 10 663 466 36 36.4 9.1 17.3 R2 83 10 7 647 489 30.2 34.4 7.7 11.7 R6 84.6 10 5.4 626 451 33.4 34.3 9.1 14.5 R8 82 10 8 624 474 30 33 8.7 14.1 R13 83 10 7p Epirez 657 479 35.5 36.8 8.7 17.9 5003 Y1 92 0 6 2 649 503 34.4 35.2 9.4 16.3 D6 86 10 2 2 7.6 10.1 Y2 96 0 1 3p Epirez 661 36.7 8.6 13.2 5003 D10 86 10 1 3p Epirez 7.4 10.7 5003 DXX 82 10 6 2p Epirez 648 32.8 8.5 13.6 5003 Thermal dimensional stability creep test, (load: 8 kg/10 cm, 200? C., 15 min) Styrene (the lower the better) Melamine maleic Epoxy Load % % shrinkage Latex formaldehyde acid Epoxysilane resin at Elongation elongation (perpendicular XZ resin copolymer (CoatOsil dispersion break at break (in load to load 96904 Starch (Saduren163) (Xiran 40005) 2287) None (N/5 cm) (%) direction) direction) Rx2 83 10 7 573 27.2 8.7 13.9 DX6 84.6 10 4.6 2 601 29 9.1 14.6

[0196] Solids content of Xiran 40005 was 30 wt %. Styrene content of 52% and weight average molecular weight of 5000 (available from Polyscope).

[0197] Solids content of Latex XZ 97223 (Trinseo) was 50 wt % and is a carboxylated styrene/butadiene/acrylate/acrylonitrile latex functionalized with hydroxyl alkyl acrylate, having a glass transition temperature of 34? C. and a particle size of about 110 nm.

[0198] XZ 96904 (Trinseo) is a carboxylated styrene/butyl acrylate latex functionalized with a hydroxyl alkyl acrylate with a Tg of 29? C. and a particle size of about 170 nm.

[0199] The solids content of Epirez 5003 was 58 wt %.

[0200] All components in Table 1 are reported in parts on a dry weight basis.

[0201] Saduren 163 (available from BASF) is a hard melamine formaldehyde crosslinking resin (74% in water as a solution).

[0202] Formulations R2 and RX2 are state of the art formulations for non-woven for bituminized water proofing membranes (with either XZ 97223 or XZ 96904). They contain 7 p (parts) of a melamine formaldehyde resin as crosslinker Saduren 163), and accordingly releases significant amount of formaldehyde, exposing workers to it. Formulations R2 (and RX2) provide TDS target values for the corresponding latex. Any alternative crosslinker system or formulation, in order to be useful, should provide a TDS which is the same or better (i.e. lower deformation values).

[0203] Formulation R1 is similar to the R2 formulation but without any crosslinker. The effectiveness of a crosslinker or crosslinker combination was assessed by the improvement in TDS relative to formulation R1.

Epoxysilane Alone as Replacement of Melamine Formaldehyde Crosslinker

[0204] Formulation R6 uses epoxysilane (CoatOSil 2287) at 5.4 p as a substitute of melamine formaldehyde resin. TDS was only marginally better than for the crosslinker free formulation R1, and did not meet the target TDS values given by the melamine formaldehyde containing formulation R2.

[0205] This indicated that the epoxysilane when used as single crosslinking component as replacement of melamine formaldehyde resin did not provide the required end use characteristics for the impregnated non-woven, and had a poor crosslinking efficiency of the binder.

Styrene Maleic Acid Copolymer as Replacement of Melamine Formaldehyde Crosslinker

[0206] Formulation R8 provided styrene maleic acid copolymer (Xiran 40005) at 8 p as a substitute for melamine formaldehyde resin. TDS was only marginally better than for the crosslinker free formulation R.sup.1, and did not provide the target TDS values given by the melamine formaldehyde containing formulation R2.

[0207] The results indicated that styrene maleic acid copolymer when used as single crosslinking component as replacement of melamine formaldehyde resin did not provide the desired end use characteristics for the impregnated non-woven, and had a poor crosslinking efficiency of the binder.

Waterborne Epoxy Dispersion as Replacement of Melamine Formaldehyde Crosslinker

[0208] Formulation R13 provided a waterborne epoxy dispersion (Epirez 5003) at 7 p as a substitute for melamine formaldehyde crosslinker. TDS was not improved as compared to the crosslinker free formulation R1, and did not provide the target TDS values of the melamine formaldehyde containing formulation R2.

[0209] The results indicated that the waterborne epoxy dispersion, when use as a single crosslinking component as replacement for melamine formaldehyde resin, did not provide sufficient crosslinking of the binders and did not provide the desired end use characteristics for the impregnated non-woven.

[0210] Synergy between epoxysilane and waterborne epoxy dispersion

[0211] Formulation D10 combined 1 p of an epoxysilane and 3 p of a waterborne epoxy dispersion. As shown by formulations R6 and R13, each of the components when used alone as a replacement of the melamine formaldehyde, did not provide a binder that resulted in the target TDS values (formulation R2), and did not result in a significant improvement of TDS compared to the crosslinker free formulation R1.

[0212] Surprisingly, epoxysilane and the waterborne epoxy dispersion utilized in combination provided suitable TDS values, demonstrating a pronounced improvement compared to the crosslinker free formulation, R1. It was even more an unexpected achievement, considering the low concentrations of the epoxysilane and the waterborne epoxy dispersion, respectively of 1 p and 3 p, lower than the 7 p of melamine formaldehyde resin of reference formulation R2.

[0213] These results demonstrate that the combination of epoxysilane and waterborne epoxy dispersion, even at amounts as low as 1 p and 3 p, respectively, had a noticeable crosslinking effect of the binder formulation, comparable to the melamine formaldehyde crosslinker.

[0214] In contrast, an epoxy silane or a waterborne epoxy dispersion when used alone, did not perform as well as the combination of the two. This result surprisingly demonstrated a strong synergistic effect between the epoxysilane and the waterborne epoxy dispersion (the combination performed much better than the simple additive effect of each of them).

[0215] This synergistic effect further allows for lower amounts for the epoxysilane as well as for the epoxy dispersion, which helps to mitigate total formulation cost increases.

[0216] These formulations are also formaldehyde free and do not release formaldehyde upon curing.

[0217] CoatOsil 2287 is classified according to Regulation EC No 1272/2008 as Skin Sens. Category 1 H317. Waterborne epoxy dispersion CPL regulation (Regulation EC No 1272/2008) depends on the epoxy resin molecular weight. Epirez 5003 used in example of the invention has following classification according regulation EC 1272/2008. Skin Corr./Irrit. Category 2 H315, Eye Dam./Irrit. Category 2 H319, Skin Sens. Category 1 H317, Aquatic Chronic Category 2 H 411

[0218] As a result, this combination can be used safely, without exposing workers to EH&S issues, providing that standard personal protective equipment (gloves and safety glasses) are worn by workers. In particular, there is no carcinogenic or teratogenic risk like that for melamine formaldehyde crosslinkers.

Synergy Between Epoxysilane and Styrene Maleic Acid Copolymer

[0219] Formulation D6 according to the invention, combines 2p epoxysilane and 2p of styrene maleic acid copolymer (Xiran 40005). As shown by formulations R6 and R8, each of these components when used alone as a replacement of melamine formaldehyde, did not provide target TDS values (formulation R2), and did not result in any significant improvement of TDS compared to the crosslinker free formulation R1.

[0220] Surprisingly, epoxysilane and styrene maleic acid used in combination provided the target TDS values, demonstrating a pronounced improvement compared to the crosslinker free formulation. It was even more an unexpected achievement, considering the low concentration of the epoxysilane and the styrene maleic acid, respectively of 2 p and 2 p, lower than the 7 p of melamine formaldehyde resin of reference formulation R2. Note that formulation DXX in Table 1 did not fully work where an epoxy was substituted for an epoxysilane.

[0221] According to formulation DXX, TDS was improved compared to formulation R1 (free of crosslinker), which demonstrates some degree of efficiency. However TDS is not at target (as given by R2) or not as good as formulation D6. It surprisingly shows that the combination of SMA+epoxy silane has a strong synergistic effect, whereas for SMA+epoxy dispersion this effect is much lower.

[0222] The results demonstrate that the combination of epoxysilane and styrene maleic acid, even at amounts as low as 2 p and 2 p, respectively, had a noticeable crosslinking effect of the binder formulation, at least equivalent to the melamine formaldehyde crosslinker, R2.

[0223] In contrast, both the epoxysilane or the styrene maleic acid when used alone performed poorly, however, the combination of both of them performed extremely well. This result demonstrated a strong synergistic effect between the epoxysilane and the styrene maleic acid (the combination performed much better than the simple additive effect of each of them).

[0224] This synergistic effect further allows for decreased amounts for the epoxysilane as well as for the styrene maleic acid, which helps to mitigate total formulation cost increase.

[0225] These formulations are also formaldehyde free and do not release formaldehyde upon curing.

[0226] CoatOsil 2287 is classified according to Regulation EC No 1272/2008 as Skin Sens. Category 1 H317. Waterborne epoxy dispersion CPL regulation (Regulation EC No 1272/2008) depends on the epoxy resin molecular weight.

[0227] Styrene maleic acid copolymers have no health issues and are not classified according Regulation EC No 1272/2008.

[0228] Examples with formulation of the epoxysilane or the epoxysilane and the styrene maleic acid copolymer into the latex & examples with variation of the amount of starch in the formulation

Test Conditions:

[0229] Non-woven base B: PET spunbond, glass fiber thread reinforced in Machine direction: 160 gsm, reinforced in MD with continuous glassfiber threads (13 threads per 10 cm), sheets of 45 cm (in MD)?27 cm (in CD).

Impregnation Conditions:

[0230] Soaking time of substrate in formulation: 2 minutes [0231] Formulation SC=13.5% (SC=solids content) [0232] Foulard pressure: 2.5 barsingle pass [0233] Drying time: 8 min@180? C., fan speed 2000 rpm, Mathis Oven [0234] Pick up: ca 20.5%-21.5%
Thermal dimensional stability testing [0235] load in MD: 8 kg/10 cm, 200? C., 10 min. (this is same as for previous examples) [0236] load in CD: 4 kg/10 cm, 200? C., 10 min.

[0237] Application of the load in CD allows the determination of the

[0238] contribution of the binder formulation only, independently of the effect of the reinforcing glass fibers.

Results

[0239] Examples 1 to 3: demonstrated that the Epoxysilane can be formulated into the latex 3 weeks before impregnation. SRS 1759=XZ 97223 formulated with 1.75% of CoatOsil 2287 prepared 3 weeks before impregnation.

[0240] Example 4 demonstrated that both the Epoxysilane and the Xiran can be formulated into the latex 6 weeks before impregnation. SRS 1663=XZ 97223+4.5% Xiran 40005+1.8% CoatOsil 2287 prepared 6 weeks before impregnation.

[0241] Examples 1 to 3 were compared to Reference sample 1 to reference 3, which compares the formaldehyde free crosslinking of the present embodiments (combination of an epoxysilane and Xiran) to the state of the art crosslinked melamine formaldehyde resin (Saduren 163) with different amounts of starch in the formulation. The TDS with load in CD (thermal dimensional stability with load in cross direction) with the inventive embodiments is better than the reference examples (lower elongation and shrinkage values). See Table 2.

TABLE-US-00002 TABLE 2 Spunbond Base B TDS, load TDS, load in Impregnation formulation Load at Elongation in CD 4 kg, Machine 8 kg, Latex composition Break at break 200? C., 15 min 200? C., 15 min latex Coat- (N/5 cm) (%) % % % % ref latex Osil Xiran latex Saduren Xiran Starch MD CD MD CD elongation shrinkage elongation shrinkage Ref 1 XZ 86.5 3.5 10 725 403 26.2 33.9 8.6% 7.1% 1.0% 1.0% 97223 Ref 2 XZ 88.5 3.5 8 731 433 28.9 35.6 8.7% 8.0% 1.2% 1.2% 97223 Ref 3 XZ 90.5 3.5 6 766 429 30.0 35.4 8.7% 8.3% 0.3% 0.7% 97223 Ex 1 SRS XZ 1.75 86 4 10 593 414 26.4 32.5 7.4% 7.7% 1.0% 1.7% 1759 97223 Ex 2 SRS XZ 1.75 88 4 8 570 463 29.8 32.7 6.8% 7.4% 0.7% 1.3% 1759 97223 Ex 3 SRS XZ 1.75 90 4 6 577 468 27.4 32.2 6.5% 7.5% 0.8% 1.0% 1759 97223 Ex 4 SRS XZ 1.8 4.5 90 10 594 455 26.9 33.0 7.3% 7.1% 0.5% 1.0% 1663 97223
Examples of the Crosslinking System in Formulation with SA (Styrene Acrylate) Latex

[0242] Test conditions are the same as above.

Results

[0243] These two formulations were to test a formaldehyde free crosslinking system for a styrene acrylate latex.

[0244] Reference 4 is the formulation free of any crosslinker. The latex used was SRS 1742, which is a styrene, butyl acrylate, acrylonitrile latex. Solids content of Latex SRS 1742 is 50 wt % and is a carboxylated styrene/butylacrylate/acrylonitrile latex functionalized with hydroxyl alkyl acrylate, having a glass transition temperature of 32? C. and a particle size of about 190 nm.

[0245] Example 5 was a formulation that was a combination of Xiran and CoatOsil used as crosslinker. The CoatOsil was formulated directly into the latex SRS 1745 (=SRS 1742+1.75% CoatOsil 2287), the Xiran was added as the binder formulation. SRS 1745 was prepared 3 weeks before preparation of the binder formulation and the impregnation.

[0246] Table 3 demonstrates that the formaldehyde free crosslinking system of the embodiment effectively crosslinks and improves the TDS performances versus a formulation without a crosslinker.

TABLE-US-00003 TABLE 3 Spunbond Base B Impregnation formulation TDS, load TDS, load in Latex (optionally Load at Elongation Load at 15% in CD 4 kg, Machine Direction, formulated) Break at break elongation 200? C., 15 min , 8 kg, 200? C., 15 min latex Base Coat- (N/5 cm) (%) (N/5 cm) % % % % ref latex Osil latex Saduren Xiran Starch MD CD MD CD MD CD elongation shrinkage elongation shrinkage Ex 4 SRS 90 10 583 460 33.3 36.6 398 300 6.5% 7.5% 0.8% 1.0% 1742 Ex 5 SRS 1.75 86 4 10 589 453 29.6 35.2 423 302 7.3% 7.1% 0.5% 1.0% 1745

Example of a Stapled Fiber Non-Woven Base

Test Conditions

[0247] Base: Non-woven base C: Polyester staple fibers nonwoven of grammage of 95 gsm, reinforced in MD with continuous glass fiber threads (13 threads per 10 cm), sheets of 45 cm (in MD)?27 cm (in CD).

[0248] For this base the reference formulation has a much higher amount of melamine formaldehyde (Saduren 163) as a crosslinker; 26 p instead of 10 p in the case of the previously used spunbond base A and B.

Impregnation Conditions:

[0249] Soaking time: The polyester staple fibers nonwoven base C was soaked in the formulation for 30 seconds at ambient conditions. [0250] Formulation: SC=13.5% [0251] Foulard pressure: 2.5 barsingle pass [0252] Drying: 8 min at 80?C., fan speed 2000 rpm [0253] Pick up: ca 18% (on final weight) or 21.5% on base weight
Thermal dimensional stability testing [0254] Load in Cross direction: 4 kg/10 cm, @200? C. for 10 min

[0255] Application of the in the CD allowed determination of the contribution of the binder formulation only, independently of the effect of the reinforcing glass fibers.

Results

[0256] Reference 5 was a formulation without any crosslinker. It is characterized by poor TDS; i.e. high elongation and shrinkage.

[0257] Reference 6 was the state of the art formulation, containing 26 p of a melamine formaldehyde crosslinker. Because of this high content the EH&S risks related to the formaldehyde is of particular concern. In such a case a formaldehyde free crosslinking system is of particular benefit.

[0258] Examples 6 and 7 are representative of the crosslinking system of the current embodiments. The TDS performances are much improved compared to the crosslinking free formulation reference 5, demonstrating the crosslinking efficiency of the embodiments. The TDS performances remained slightly lower than for the reference 6 with 26 p of melamine formaldehyde system. This is because the overall amount of crosslinker is much lower; the totals of Xiran and CoatOsil are between 9 p and 14 p, whereas the melamine formaldehyde resin is at 26 p. See Table 4.

[0259] Examples 6 and 7 have the further advantage of a significantly higher elongation at break compared to that of reference 6.

TABLE-US-00004 TABLE 4 Spunbond Base C Styrene Melamine Maleci acid TDS-load in CD, 4 kg- formaldehyde copolymer Epoxysilane load at 10 Min. resin (Xiran (CoatOsil break elongation % % Latex Starch (Saduren 163) 40005) 2287) (N/5 cm) at break elongation shrinkage Ref 5 XZ 97223: 65p 35 242 48.8 21.8% 28.4% Ref 6 XZ 97223: 39p 35 26 210 28.3 14.2% 8.5% Ex 6 XZ 97223: 51p 35 10 4 229 40 17.1% 14.0% Ex 7 XZ 97223:53p 35 10 2 223 39.8 17.6% 15.5% Ex 8 XZ 97223: 59p 35 6 3 210 38.3 18.3% 16.4%

[0260] Although the present invention has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. All references cited throughout the specification, including those in the background, are incorporated herein in their entirety. Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, many equivalents to specific embodiments of the invention described specifically herein. Such equivalents are intended to be encompassed in the scope of the following claims.