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Title:
METHOD FOR IMPREGNATION OF SYNTHETIC AND NATURAL FABRICS
Document Type and Number:
WIPO Patent Application WO/2016/056931
Kind Code:
A1
Abstract:
Method for impregnation of synthetic and natural fabrics consisting in the fabric impregnation in a bath containing a binder, at least one dispersing agent, and at least one antifoaming agent, characterised in that the fabric is subject to impregnation in the bath composed of 20 to 80% by wt. of a water-dilutable binder being a water polymer dispersion; 2 to 20% by wt. of dispersed inorganic oxide pigments with a crystallographic structure of rutile (TiO2) or spinel (MgAl2O4) or hematite/corundum (Fe2O3/Al2O3) with the total solar reflectance (TSR) value not lower than 20% and not higher than 99%; auxiliaries, including: 0.1 to 2% by wt. of dispersing agents, 0.05 to 2% of antifoaming agents, and 0.05 to 1,5% by wt. of bactericidal agents, and water in an amount supplementing the composition to 100% by wt.; and then, the so-impregnated fabric is dried at a temperature above 80°C.

Inventors:
KUCZYŃSKA HELENA (PL)
LANGER EWA (PL)
KAMIŃSKA-TARNAWSKA ELŻBIETA (PL)
WOŹNICZKA AGNIESZKA (PL)
MANN GABRIELA (PL)
BORTEL KRZYSZTOF (PL)
Application Number:
PCT/PL2015/050052
Publication Date:
April 14, 2016
Filing Date:
October 05, 2015
Export Citation:
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Assignee:
INST INŻYNIERII MATERIAŁÓW POLIMEROWYCH I BARWNIKÓW (PL)
International Classes:
D06M11/44; D06M11/45; D06M11/46; D06M11/49; D06M15/263; D06M15/564; D06M15/647; D06M16/00; D06M23/08
Foreign References:
CN101435158A2009-05-20
US20100047620A12010-02-25
PL215349B12013-11-29
PL134689B11985-09-30
EP2588543A12013-05-08
PL213433A11980-09-08
Other References:
H.AKBARI; H.D.MATHEWS: "Global cooling updates: Reflective roofs and pavements", ENERGY AND BUILDINGS, vol. 55, December 2012 (2012-12-01), pages 2 - 6
PIER FINAL PROJECT REPORT, COOL-COLOR ROOFING MATERIAL, 2006
R. DOYLE, UNDERSTANDING COOL COATINGS FOR AUTOMOTIVE, 2009, Retrieved from the Internet
E. LANGER; H. KUCZYNSKA; M. GRZELAK: "Ecological solar reflecting coatings for renovation of roof", IZOLACJE, 2014, pages 38 - 41
Attorney, Agent or Firm:
CZARNIK, Maciej (ul. Ujejskiego 12/7, Kraków, PL)
Download PDF:
Claims:
Claims

1. Method for impregnation of synthetic and natural fabrics consisting in the fabric

impregnation in a bath containing a binder, at least one dispersing agent, and at least one antifoaming agent, wherein the fabric is subject to impregnation in the bath composed of: a. 20 to 80% by wt. of a water-dilutable binder being a water polymer dispersion, b. 2 to 20% by wt. of dispersed inorganic oxide pigments with a crystallographic structure of rutile (T1O2) or spinel (MgAl204) or hematite/corundum (Fe203/Al203) with the total solar reflectance (TSR) value not lower than 20% and not higher than

99%,

c. auxiliaries, including: 0.1 to 2% by wt. of dispersing agents, 0.05 to 2% of

antifoaming agents, and 0.05 to 1,5% by wt. of bactericidal agents; and d. water in an amount supplementing the composition to 100 % by wt.,

and then, the so-impregnated fabric is dried at a temperature above 80°C.

2. The method according to claim 1, wherein the binder is a water dispersion of an acrylic polymer, or a polyurethane polymer, or a polyurethane -acrylic polymer with a glass transition temperature (Tg) in the range of -5°C to +25°C.

3. The method according to claim 2, wherein the polymer glass transition temperature (Tg) is in the range of 0°C to +5°C.

4. The method according to claim 1, wherein the dispersed inorganic oxide pigments with a crystallographic structure of rutile (T1O2) or spinel (MgAl204) or hematite/corundum (Fe203/Al203) have values of the total solar reflectance (TSR) coefficient not lower than 26% and not higher than 99%.

5. The method according to claim 1, wherein dispersing agent are constituted by a 40%

solution of a block copolymer with a high molecular mass and containing groups exhibiting affinity to the pigments' surface.

6. The method according to claim 1, wherein the antifoaming agents are constituted by a water emulsion of a polyethersiloxane acid.

7. The method according to claim 1, wherein the bactericidal agents constitute a mixture of isothiazolinones, most preferably a water solution 5 -chloro-2 -methyl -4-isothiazolinone and 2-methy 1-4-isothiazolinone .

8. The method according to claim 1, wherein the impregnation bath additionally contains not more than 10% by wt. of classic coloured pigments.

9. The method according to claim 1, wherein the impregnation bath additionally contains, as an auxiliary agent, not more than 2% by wt. of pH stabilisers.

10. The method according to claim 1, wherein the impregnation bath additionally contains, as an auxiliary agent, not more than 5% by wt. of agents regulating the rheological properties of the bath.

11. The method according to claim 10, wherein the agents regulating the rheological properties of the bath are constituted by a hydrophobically modified acrylic polymer.

12. The method according to claim 1, wherein the impregnation bath additionally contains not more than 20% of mineral fillers.

13. The method according to claim 1, wherein the fabric is dried at a temperature not higher than 150°C.

Description:
Method for impregnation of synthetic and natural fabrics

The invention relates to a method for impregnation of synthetic and natural fabrics, conferring especially properties of reflection of solar rays on the fabrics. The method is used particularly for coated fabrics used for production of window blinds, awnings, tourist equipment, such as tents, tarpaulins, sportswear etc.

Various methods for modification of surface of woven fabrics and/or synthetic and natural fibres are known, consisting in coating them with a layer of an impregnant in order to obtain the required properties. Most often, the impregnation of synthetic and natural fabrics commonly used in the textile industry gives the surfaces of the fabrics hydrophobic properties increasing waterproofness, reducing the tendency to become dirty, facilitating cleaning, or provides the fabrics with bacteri- and fungicidal (patent application PL215349 Bl), antistatic and/or flame retardant (patent application PL134689) properties. The enumerated methods for the fabric impregnation with formation of coatings having specific usable features do not protect these materials from being heated in the result of absorption of solar radiation, particularly in the infrared range (700 - 2500 nm), subsequently emitted in the form of thermal energy.

For several years now, literature reports are being published (H.Akbari, H.D.Mathews "Global cooling updates: Reflective roofs and pavements" Energy and Buildings, Vol. 55, December 2012, 2-6; "Cool-Color Roofing Material" PIER Final Project Report, 2006; R. Doyle, www.pcimag.com Understanding Cool Coatings for Automotive, 2009; E. Langer, H. Kuczynska, M. Grzelak "Ecological solar reflecting coatings for renovation of roof" , Izolacje, nr 4/2014, 38-41), relating to coatings with properties of reflection of solar radiation, protecting from excessive heating of surfaces and intended for wide range of applications - from application in building industry (so-called "cool roof for roofing or sidings), in road engineering (for road markings), in automotive industry (dashboards, car seats, car bodies etc.).

The patent application EP2588543 Al discloses constitution of a binary coating composition conferring a reduced sensitivity to thermal deformation on products manufactured from thermoplastics. In the results of application of this composition containing a water- dilutable binder with active hydroxyl groups, a water-dispersible polyisocyanate, and a coloured pigment not absorbing infrared radiation, a well-adhesive coloured coating reflecting infrared radiation is formed after curing. The coating composition may be used for coating prefabricated products made of thermoplastics or their composites, such as: window frames, doors, siding panels, by commonly used methods: air spraying, airless spraying, electrostatic spraying, roller coating, glazing, and immersion.

The patent application PL213433 discloses a water-dilutable coating composition containing pigments and fillers, and auxiliaries, consisting of 10% to 80% by wt. of a binder, constituted by water dispersions of an acrylic copolymer with a glass transition temperature (T g ) in the range of -25 °C to -15°C and preferably with a minimum film forming temperature (MFFT) of approx. 0°C, 20% to 60% by wt. of a pigment mixture, preferably titanium white and phthalocyanine blue or iron oxide black, and mineral fillers, preferably magnesium silicate and calcium carbonate or magnesium carbonate, including those with spherical and/or lamellar grain shape, 0.05% to 5% by wt. of a wetting and dispersing agent, preferably polyacrylic acid sodium salt, 0.10% to 5% by wt. of an antifoaming agent, preferably water emulsions of a polyethersiloxane, 0.1% to 10% by wt. of a rheological agent containing acrylic polymers, preferably a 30% emulsion of a hydrophobically modified acrylic copolymer containing acrylic polymers and/or polyurethane polymers, preferably a 40% emulsion of a hydrophobically modified polyurethane, 0.05% to 2% by wt. of a bactericidal agent, preferably a mixture of isothiazolinones, and 0.0% to 2% of aqua ammonia. The share of a filler or fillers with spherical and/or lamellar grain shape in the total amount of mineral fillers is 1% to 90% by wt.-The conventional pigments applied, having a low value of the total solar reflectance (TSR) coefficient absorb a major part of solar radiation, causing - while exposed to sunlight - excessive heating of surfaces, particularly dark-coloured surfaces.

Solutions known from the state of art do not disclose any method for impregnation of synthetic and natural fabrics providing properties of reflection of solar rays for these products.

The essence of the invention is constituted by a method for impregnation of synthetic and natural fabrics consisting in impregnation of a fabric in a bath containing a binder, at least one dispersing agent and at least one antifoaming agent characterised in the:

the fabric is subject to impregnation in the bath composed of: 20 to 80% by wt. of a water-dilutable binder being a water polymer dispersion; 2 to 20% by wt. of dispersed inorganic oxide pigments with a crystallographic structure of rutile (Ti0 2 ), or spinel (MgAl 2 0 4 ), or hematite/corundum (Fe 2 0 3 /Al 2 0 3 ) with the total solar reflectance (TSR) value not lower than 20% and not higher than 99%; auxiliaries, including: 0.1 to 2% by wt. of dispersing agents, 0.05 to 2% of antifoaming agents, and 0.05 to 1,5% by wt. of bactericidal agents; and water in an amount supplementing the composition to 100% by wt.; and then, the so-impregnated fabric is dried at a temperature above 80°C.

Preferably, the binder is a water dispersion of an acrylic polymer, or a polyurethane polymer, or a polyurethane-acrylic polymer with a glass transition temperature (T g ) in the range of -5°C to +25 °C. Especially preferably, the polymer glass transition temperature (T g ) is in the range of 0°C to +5°C.

Equally preferably, the dispersed inorganic oxide pigments with a crystallographic structure of rutile (T1O 2 ) or spinel (MgAl 2 0 4 ) or hematite/corundum (Fe 2 0 3 /Al 2 0 3 ) have values of the total solar reflectance (TSR) coefficient not lower than 26% and not higher than 99%.

Preferably, the dispersing agent constitutes a 40% solution of a block copolymer with a high molecular mass and containing groups exhibiting affinity to the pigments' surface. Equally preferably, the antifoaming agents are constituted by a water emulsion of a polyethersiloxane acid. Also preferably, the bactericidal agents constitute a mixture of isothiazolinones, most preferably a water solution of 5-chloro-2-methyl-4-isothiazolinone and 2-methyl-4- isothiazolinone.

Preferably, the impregnation bath additionally contains not more than 10% by wt. of classic coloured pigments. Equally preferably, the impregnation bath additionally contains, as an auxiliary agent, not more than 2% by wt. of pH stabilisers.

Preferably, the impregnation bath additionally contains, as an auxiliary agent, not more than 5% by wt. of agents regulating the rheological properties of the bath. Especially preferably, the agents regulating the rheological properties of the bath are constituted by a hydrophobically modified acrylic polymer.

Preferably, the impregnation bath additionally contains not more than 20% of mineral fillers.

Also preferably, the fabric is dried at a temperature not higher than 150°C.

The conventional colouring pigments include inorganic pigments, such as titanium white, iron oxide-based pigments such as iron oxide red, iron oxide black, ferrite yellow, and organic pigments, including carbon black.

The mineral fillers, which may be optionally used in the fabric impregnation method according to the invention, include calcium carbonates, magnesium silicates, aluminosilicates, silicas, and kaolins.

The method for impregnation of synthetic and natural fabrics conferring properties of reflection of solar rays on them was achieved by using white and/or coloured pigments with an exceptional spectral characteristics for colouring of the impregnation bath. In the fabric impregnation method, inorganic oxide pigments with a crystallographic structure of rutile, spinel or hematite/corundum were used for colouring of the impregnation bath. These pigments are characterised by a relatively high radiation reflectance in the range of near infrared. Application of pigments having a high value of the total solar reflectance (TSR) coefficient leads basically to a reduction of heating of their surface while exposed to solar radiation. The high TSR values of these pigments result from their ability to reflect the major part of solar radiation incident onto a surface coloured with them. The non-reflected radiation is absorbed by the surface or the substrate, and emitted in the form of long-wavelength thermal energy.

The impregnation bath with the mentioned composition exhibits a very good stability and it may be stored for a period of up to six months. The method according to the invention may be carried out using machinery employed for the fabric impregnation. During drying of the fabrics, water evaporates and the polymer molecules coalesce forming a uniform coating, fixed to the fibre of the fabric. The process of drying of the fabrics impregnated using the method according to the invention is carried out at temperatures from 80 to 150°C in tunnel dryers. The fabrics impregnated using the method according to the invention exhibit a good elasticity, and when the impregnant is applied in the amount of approx. 300±50 g/m 2 depending on the type of the fabric, they are characterised by a low absorptivity of solar radiation.

Application of the method for impregnation of synthetic and natural fabrics conferring the properties of reflection of solar rays on them according to the invention allows for counteracting the effects of excessive solar radiation and simultaneously: a) in case of window blinds - it yields a reduction in the temperatures in rooms and a comfort improvement, power savings connected with a reduction or elimination of air-conditioning use, b) in case of tourist equipment and sportswear - it yields a reduction in their heating and therefore a comfort improvement for the user, c) it increases the durability of the products while exposed to solar radiation.

The subject of the invention is shown in more detail in the following embodiment examples.

Example 1

For the fabric impregnation, a bath with the following composition shown in Table 1 was prepared, having chocolate brown colour according to the RAL 8017 colour standard: Table 1.

1. Water dispersion of an acrylic polymer with T g = -3°C 30.40 parts by wt.

2. C.I.Pigment Brown 33 containing Fe, Cr, Zn, Ti (spinel) and having the 5.20 parts by wt.

TSR value of 38%

3. C.I.Pigment Green 17 containing Fe, Cr (hematite) and having the TSR 8.87 parts by wt.

value of 26%

4. C.I.Pigment Red 101 (iron oxide red Fe 2 0 3 ) 0.33 parts by wt.

5. Dispersing agent - a 40% water solution of a block copolymer with a high 0.49 parts by wt.

molecular mass, containing groups exhibiting affinity to the pigments' surface

6. Antifoaming agent - a 30% emulsion of siloxylated polyethers in water 0.10 parts by wt.

7. Thickening agent - a hydrophobically modified acrylic polymer 0.60 parts by wt.

8. Bactericidal agent - a water solution of 5-chloro-2-mefhyl-4- 0.05 parts by wt.

isothiazolinone and 2-methyl-4-isothiazolinone

9. Water 53.96 parts by wt.

100.00 parts by wt.

The pigments are pre-dispersed under a high-speed stirrer, and then dispersed in a bead mill, until a trituration degree of the pigments below 15 pm according to PN-EN 21524/AK: 1994 is obtained. For comparison of properties of the prepared impregnation bath according to Example 1, an impregnation bath with the same colour was prepared using conventional pigments: red iron oxide and iron oxide black.

The so-prepared baths are used to impregnate a viscose fabric with a grammage of 120 g/m 2 on an impregnation machine and the fabric is dried in a tunnel at a temperature from 80°C in the first chamber, do 120°C in the last chamber. The applied quantity of the impregnant is adjusted by regulating the size of the gap of the top rollers, and the efficiency of drying - by regulating the fabric travel speed. The fabric impregnated in the bath according to Example 1 is characterised by a high appret durability and a low absorptivity of solar radiation. The fabrics may be used for production of window blinds preventing heating of rooms.

This is confirmed by measurements of spectral properties of the fabric impregnated according to the Example 1 and the one impregnated according to the conventional method. The TSR value was determined according to ASTM E903-12 "Standard Test Method for Solar Absorptance, Reflectance and Transmittance of Materials Using Integrating Spheres" using a double-beam spectrophotometer UV/VIS/NIR V-670 with an integrating sphere. Heating of surfaces of both fabrics, measured as the temperature increase using a pyrometer, was examined in a heating chamber designed and constructed according to ASTM D4803-10 "Standard Test Method for Predicting Heat Buildup in PVC Building Products" and in the field, on a hot day with an air temperature of 30°C. The results are shown below in Table 2. Table 2.

The obtained results indicate a significant influence of the fabric impregnation method on the heating of the fabric surface and the ability to design the radiation properties of the material. A significantly higher TSR value (28%) for the fabric impregnated according to Example 1 than that for the fabric impregnated in the conventional way (7%) contributes into a significantly less intense heating of the fabric impregnated according to Example 1, being confirmed by lower temperatures of the fabric surface while compared to the one impregnated in the conventional way, both in the test acc. to ASTM D4803-10, and in the field.

Example 2

For the fabric impregnation, a bath with the following composition shown in Table 3 was prepared, having window grey colour according to the RAL 7040 colour standard:

Table 3.

1. Water dispersion of an acrylic polymer with Tg = 0°C 32.00 parts by wt.

2. C.I.Pigment White 6 containing Ti0 2 (rutile) and having the TSR value 1.50 parts by wt.

of 86 %

3. C.I.Pigment Green 17 containing Fe, Cr (hematite) and having the TSR 4.12 parts by wt.

value of 28%

4. C.I.Pigment Blue 36 containing Co, Cr, Al (spinel) and having the TSR 0.23 parts by wt.

value of 31%

5. Dispersing agent - a 40% water solution of a block copolymer with a 0.50 parts by wt.

high molecular mass, containing groups exhibiting affinity to the

pigments' surface

6. Antifoaming agent - a 30% emulsion of siloxylated polyethers in water 0.10 parts by wt.

7. Thickening agent - a hydrophobically modified acrylic polymer 0.60 parts by wt.

8. Bactericidal agent - a water solution of 5-chloro-2-mefhyl-4- 0.05 parts by wt.

isothiazolinone and 2-methyl-4-isothiazolinone

9. Water 60.90 parts by wt.

100.00 parts by wt. The pigments are pre-dispersed under a high-speed stirrer, and then dispersed in a bead mill, until a trituration degree of the pigments below 15 μιη according to PN-EN 21524/AK: 1994 is obtained. For comparison of the properties of the prepared impregnation bath according to Example 1, an impregnation bath with the same colour was prepared using conventional pigments: rutile-type titanium white and iron oxide black.

Then, the so-prepared mixtures are used analogically as in Example 1, with the exception that the baths are used to impregnate a viscose fabric with a grammage of 120 g/m 2 on an impregnation machine and the fabric is dried in a tunnel at a temperature from 80°C in the first chamber, do 150°C in the last chamber. Measurements of spectral properties of the fabric impregnated according to the Example 2 and the one impregnated according to the conventional method were carried out. The results are shown below in Table 4.

Table 4.

The obtained results, similarly as in Example 1, indicate a significant influence of the fabric impregnation method on the heating of the fabric surface. A significantly higher TSR value (48%) for the fabric impregnated according to Example 2 than that for the fabric impregnated in the conventional way (15%) contributes into a significantly less intense heating of the fabric impregnated according to Example 1, being confirmed by lower temperatures of the fabric surface while compared to the one impregnated in the conventional way, both in the test acc. to ASTM D4803-10, and in the field.

Example 3

For the fabric impregnation, a bath with the following composition , having olive green colour according to the RAL 6003 colour standard. Table 5.

1. Water dispersion of an acrylic polymer with T g = -3°C 38.00 parts by wt.

2. C.I.Pigment Brown 29 containing Fe, Cr (hematite) and having the TSR 1.00 parts by wt.

value of 29%

3. C.I.Pigment Green 17 containing Fe, Cr (hematite) and having the TSR 4.32 parts by wt.

value of 40%

4. Talc 8.00 parts by wt.

5. Dispersing agent - a 40% water solution of a block copolymer with a high 0.50 parts by wt.

molecular mass, containing groups exhibiting affinity to the pigments' surface

6. Antifoaming agent - a 30% emulsion of siloxylated polyethers in water 0.10 parts by wt.

7. Thickening agent - a hydrophobically modified acrylic polymer 0.55 parts by wt.

8. Bactericidal agent - a water solution of 5-chloro-2-mefhyl-4- 0.05 parts by wt.

isothiazolinone and 2-methyl-4-isothiazolinone

9. Water 47.48 parts by wt.

100.00 parts by wt.

The method for the impregnant preparation and the fabric impregnation is the same as reported for Examples 1 and 2. Measurements of spectral properties of the fabric impregnated according to the Example 3 and the one impregnated according to the conventional method were carried out. The results are shown below in Table 6.

Table 6.

The method for impregnation of fabrics according to the invention enables manufacturing of fabrics and products utilising them, with novel, exceptional properties, reflecting solar radiation, thanks to which the surfaces exposed to sunlight remain cool.