KR20240026305A - Method for conferring durable water repellence to woven or non-woven fabric and water repellent composition - Google Patents

Abstract

Disclosed is a method for imparting sustained water repellency to a fabric, whether woven or nonwoven, comprising: (1) treating the fabric with an aqueous composition, the composition comprising: (a) at least 80 w/w% water, and at least two an aqueous solvent containing 20 w/w% or less of a water miscible organic solvent containing OH functional groups, and (b) Formula 1: 0.1 to 40 w/w% of acrylic ester, where A ¹ is H or CH ₃ and A ² is C ₁ -C ₃₀ linear or branched, which may have an aliphatic ring or an aromatic ring. It is a saturated or unsaturated hydrocarbon, and the acrylic acid ester is dissolved, emulsified, or dispersed in the aqueous solvent, comprising an acrylic acid ester, (2) heating the treated fabric to 120 to 200 ° C. Includes. Such compositions and fabrics treated with such compositions are further disclosed.

Description

Method and water-repellent composition for imparting sustained water repellency to fabric or non-woven fabric {METHOD FOR CONFERRING DURABLE WATER REPELLENCE TO WOVEN OR NON-WOVEN FABRIC AND WATER REPELLENT COMPOSITION}

The present invention relates to a method for imparting sustained water repellency to a woven or non-woven fabric, a composition for imparting sustained water repellency to a woven or non-woven fabric, and a woven or non-woven fabric treated with the composition.

Methods for imparting sustained water repellency are known in the art. To date, provision of durable water repellency in fabrics has relied on fluorocarbon-based treatments that are highly effective and highly durable. However, by-products such as fluorosurfactants and derivatives based on C8 fluorosurfactants and C6 fluorosurfactants are toxic and persist in the environment, making this combination unacceptable despite its excellent performance. . Many of today's fluorine-free coatings have a short lifespan. A water-repellent rain shell deteriorates and becomes a wind shell before the garment itself wears out.

JP2020153057 describes vinyl-based polymerization of a specific divinyl compound with a molecular weight of 600 or more, which involves chemical bonding of the vinyl polymer to polyester fabric. Additional films are applied, which contain fluorinated copolymers or acrylic monomers polymerized with perfluoroalkyl groups having up to 6 carbon atoms. The additional film is crosslinked by melamine resin.

EP3919673 describes a special fabric surface that resembles the surface of lotus leaves and mimics their water-repellent properties. This artificial lotus-like surface can be treated with commonly known water-repellent properties.

In WO2016/000831, a composition for imparting water repellency for application to textiles is described, comprising three different acrylate monomers, one of which contains fluorine. The monomers are polymerized into polyacrylates with the help of an azo initiator. In addition to the polyacrylate thus obtained, the composition comprises wax.

The present invention provides a textile treatment composition and a fabric or non-woven fabric that can impart water repellency with excellent washing durability to textile products without the need to include fluorine components for water repellency and without the need for the use of silicone, isocyanate or melamine accelerators. A method for imparting sustained water repellency is provided. This method for imparting sustained water repellency to a woven or nonwoven fabric results in a highly durable and sustainable water repellent coating on the fabric, which remains unaffected after more than 100 machine washes.

To this end, the method involves the following steps:

i) treating the fabric with an aqueous composition, wherein the composition:

a. an aqueous solvent comprising at least 80 w/w% of water and up to 20 w/w% of a water miscible organic solvent containing at least two OH functional groups, and

b. Formula 1: 0.1 to 40 w/w% of acrylic ester, where A ¹ is H or CH ₃ and A ² is C ₁ -C ₃₀ linear or branched, which may have an aliphatic ring or an aromatic ring. A step comprising an acrylic acid ester, which is a saturated or unsaturated hydrocarbon, and the acrylic acid ester is dissolved, emulsified, or dispersed in the aqueous solvent, and

ii) heating the treated fabric to 120 to 200°C

Includes.

According to the method of the invention, the water-miscible solvent participates in a chemical reaction with the acrylic acid ester through its OH functional groups.

By the heat treatment step ii), a (trans)esterification reaction is initiated between the water-miscible solvent molecules and the acrylic acid ester. A C-O-C covalent bond is formed between one of the at least two OH groups of the water-miscible solvent molecule and the oxygen of the C=O group of the acrylic acid ester of Formula 1. Since the water-miscible solvent molecule has at least two OH functional groups, the acrylic acid ester acquires an OH functional group, and the ester can bind to the fabric fiber through hydrogen bridging by this OH group. Therefore, the term 'OH functional group' means that the group can form the C-O-C bond. Conditions are selected so that the reaction or reactions can take place, for example at acidic pH.

Without being bound by any scientific explanation, it is also possible for the (trans)esterification reaction to proceed, wherein the water solvent molecule forms the CH ₂ =C(A ¹ )COO moiety of the acrylate ester. ) and the A ² portion is covalently bonded to the terminal OH group. In the latter case, the A ² portion binds to the fabric fiber by hydrogen linking of its newly acquired terminal OH groups. It is also possible that the (trans)esterification reaction results in both, i.e., an incomplete esterification process and a complete esterification process, both of which result in the fiber obtaining a hydrophobic A ² moiety bonded through hydrogen linkage. It comes down to doing this. Since the result of the heat treatment is that the A ² parts are bonded to the fabric, this step is also considered a curing step.

However, it is clear that the composition of the present invention does not include an acrylate polymer, that is, a polymer comprising a plurality of acrylate monomers, especially three or more acrylate monomers polymerized with each other by, for example, using an azo initiator. Moreover, according to the above definition, it is also clear that there are no fluorine groups in the acrylic acid ester.

Suitable acrylic acid esters as defined above for step i)b. are known to the person skilled in the art, such as the Unidyne XF series (Daikin, Japan).

The heat treatment results in a fabric with fibers containing hydrophobic A ² moieties stably bonded through hydrogen entanglement, thereby achieving very strong and sustainable water repellency.

The water-miscible solvent may contain two or more OH functional groups, but the presence of two OH functional groups is preferred. Accordingly, the water-soluble solvent is preferably a water-miscible organic solvent, more preferably: ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene. Glycol Monoethyl Ether Acetate, Ethylene Glycol Monobutyl Ether Acetate, Propylene Glycol, Propylene Glycol Monomethyl Ether, Propylene Glycol Monoethyl Ether, Propylene Glycol Dimethyl Ether, Dipropylene Glycol, Dipropylene Glycol Monomethyl Ether, Dipropylene Glycol Dimethyl Ether, It is selected from the group consisting of dipropylene glycol monoethyl ether, tripropylene glycol, tripropylene glycol monomethyl ether, polypropylene glycol and hexylene glycol. Most preferred is tripropylene glycol.

The water solvent preferably contains at least 0.1 w/w% of the water-miscible solvent, and preferably contains at least 0.2 w/w% of the water-miscible solvent.

The water solvent preferably contains 90 to 99.9 w/w% of water and 0.1 to 10 w/w% of the water-miscible solvent, more preferably 95 to 99.8 w/w% of water and 0.2 to 5 w%. /w% of the water-miscible solvent, or 95 to 99 w/w% of water and 1 to 5 w/w% of a miscible organic solvent.

The composition preferably contains 0.2 to 20 w/w% of acrylic acid ester, more preferably 0.5 to 10 w/w% of acrylic acid ester, and even more preferably 1 to 6 w/w%. Contains acrylic acid ester.

For optimal water repellency, the surface tension of the coating should be approximately 25 mN/m². For this purpose, the A ² moiety is preferably alkyl. The A ² portion of the acrylic acid ester preferably has 12 to 24 carbon atoms, more preferably 12 to 21 carbon atoms, and even more preferably 18 carbon atoms. The -CH ₂ - portion imparts approximately 31 mN/m², while the terminal -CH ₃ imparts 22 mN/m². This means that a higher -CH ₃ content will have a lower surface tension and will result in a coating with stronger water repellency. Higher -CH ₃ contents can be obtained by increasing the number of branches in the hydrocarbon chain. Accordingly, the A ² portion may be linear, but preferably the portion is branched.

It was found that the coating applied to the fabric according to the above method adhered to and remained very stably on the fabric. It was observed that the fabric remained intact during 100 washing cycles operated on a regular drying program, i.e. tumble dryer with heating. However, it was observed that the coating began to wear after about 10 washing cycles when drying without additional heat (so-called “line drying”) was carried out.

The coating can be further improved by including a polyisocyanate with at least three cross-linked isocyanate groups in the aqueous composition. Surprisingly it was shown that the presence of polyisocyanate resulted in a significant increase in the stability of the coating without any noticeable wear even after 30 washing cycles followed by line drying. Both the OH functional groups of the water-miscible solvent molecules and the OH functional groups as a result of the transesterification reaction described above as well as the OH functional groups of the acrylic acid ester comprising the A ² moiety with the OH functional groups obtained in this manner are Covalently bonded to the polyisocyanate, which results in a crosslinked web of hydrophobic carbohydrate moieties, which is linked to each other through covalent bonds with the OH functional groups of the water-miscible solvent molecules. It is formed by the interconnection of isocyanate molecules. (The functional OH groups of both the water miscible solvent molecules and of the acrylic ester comprising a functional OH group as a result of the above described transesterification reaction, as well as the A ² moiety with a functional OH group obtained this way are covalently bound to the polyisocyanate, resulting in a crosslinked web of hydrophobic carbohydrate moieties, the web being formed by interconnection of the polyisocyanate molecules linked to one another via covalent linkage with the functional OH groups of the water miscible solvent molecules.) Since these molecules contain two or more OH functional groups, they connect the polyisocyanate molecules to each other, form hydrogen bridges with the fabric fibers, and form a functional group on the acrylic acid ester of the A ² portion. It has the function of providing.

The polyisocyanate may for example be aromatic or aliphatic, and suitable polyisocyanates are known to the person skilled in the art. Since the polyisocyanates are in an aqueous composition, e.g. water-based, the isocyanates are preferably blocked, e.g. phenol, nonyl phenol, methyl ethyl ketone oxime (MEKO), It is blocked by blocking groups known in the art, such as alcohols, epsilon-caprolactam (ε-caprolactam), amides, imidazoles, or pyrazoles. JP2020007657 discloses a fiber treatment composition containing water-repellent properties and such a blocked polyisocyanate. In order for the blocked polyisocyanate to become active, i.e. to be unblocked, the water must first be removed, for example by drying, followed by a subsequent heating step. A very attractive isocyanate is a trimer based on aliphatic hexamethylene-1,6-diisocyanate, especially the HDI trimer (Kowa, NY, US).

The weight ratio of acrylic acid ester:isocyanate is 100:5 to 100, preferably 100:30 to 80, more preferably 100:50 to 70, and most preferably 100:60. It has been found that a relatively high ratio of acrylic acid ester:isocyanate results in the most stable coating.

The heating in step ii) is preferably between 130 and 200°C, more preferably between 140 and 200°C, more preferably between 145 and 200°C, 180°C, even more preferably between 145 and 180°C. , even more preferably at 150 to 170°C, and most preferably at about 160°C. It has been found that such a heating step results in excellent reaction between the components (water miscible solvent and acrylic acid ester, and polyisocyanate if present) and binding to the fabric. If blocked polyisocyanate is present in the composition, the polyisocyanate is also unblocked at such temperatures.

The optimal heating temperature may also depend on the treated fabric. For example, in the case of ultra high molecular weight polyethylene, the heating temperature is preferably maintained below 140°C, especially about 130°C; exceeding this temperature may cause deformation of the material. Because there is. For other fabrics with higher temperature resistance, the drying temperature is preferably higher as described above, most preferably around 160°C. The heating step may be carried out by exposing the treated fabric to a stream of hot air, by keeping it in a heat chamber, or by ironing, for example. A person skilled in the art will know the appropriate temperature selection. The heating step is preferably carried out for 30 seconds to 10 minutes, preferably 1 to 3 minutes.

It is preferred that the fabric as treated in step i) is dried before undergoing the heating step ii). When polyisocyanates are present, such a pre-drying step becomes particularly important, since the crosslinking reaction is preferably carried out in a water-free environment. If isocyanates are not present in the composition, it is also possible to combine the heating with the drying. However, usually drying can be done at a lower temperature than heating. Heating is preferably carried out as described above, for example between 120°C and 200°C, or at 145 to 200°C, while drying is preferably carried out between 100 and 140°C, preferably at 140°C. It takes place below °C. Such pre-drying steps may therefore be more energy-saving. Drying is preferably carried out for about 1 to 10 minutes, preferably for about 1 to 3 minutes.

In a very attractive embodiment, the composition is free of silicone and/or melamine compounds, and preferably also fluorine-free for its sole function of water repellency. This means that there are no compounds having fluorine groups in their molecular backbone in the composition.

However, in order to provide a stable and wear-resistant coating that is not only water-repellent but also oil-repellent, the composition of the present invention, in an attractive embodiment, contains a fluorinated C2-C20 alkyl group containing a terminal acryl group. Compounds included, for example, as described in JP2020153057, and known in the art as, for example, the Unidyne TG series (Daikin, Japan). By including such a fluoroacrylic ester in the composition, the fluoroacrylic acid ester is a fluoroacrylic acid ester of the formula 1 described above and is easily affected by a transesterification reaction with the water-miscible solvent. will be susceptible, and will therefore result in the fluorinated hydrocarbon moiety bonded to the fabric fibers through hydrogen linkage, and will be able to participate in crosslinking with the polyisocyanate if present.

By providing such a fluorinated acrylic acid ester, not only water repellency but also oil repellency is obtained. Very attractively, the fluorinated alkyl compound is defined as a fluorinated acrylic acid ester of formula 1, for which the A ² structure is C ₆ -C ₂₀ alkyl, and 1 of its carbon atoms to 6 are completely substituted with fluorine. The term 'fully substituted with fluorine' means that all H atoms of that carbon atom have been replaced with fluorine atoms. When fully substituted, the saturated terminal carbon atom will have three fluorine atoms, and the saturated inner carbon, i.e. the carbon flanking two adjacent carbon atoms by single bonds, will have two fluorine atoms. This means that the fluorine groups may be scattered throughout the basic structure of the alkyl. Such compounds are known for example from WO2016/096128. A ² of the fluorinated compound is very attractively a C6 alkyl in which all six carbon atoms are completely substituted with fluorine.

The surface tension of -CF ₂ - groups is 18 mN/m ² , and the surface tensions of terminal -CF ₂ and -CF ₃ groups are 15 mN/m ² and 6 mN/m ² , respectively, so that terminal -CF ₂ and -CF Branched fluorinated alkyl compounds having ₃ groups, especially -CF ₃ groups are preferred.

The composition preferably contains equal amounts of both non-fluorinated acrylic acid ester and fluorinated acrylic acid ester in weight ratio (w/w%). The composition preferably comprises 0.2 to 20 w/w% of acrylic acid ester, more preferably 0.5 to 10 w/w%, and even more preferably 1 to 6 w/w% of fluorinated C ₂ -C ₂₀ Contains alkyl compounds. The weight ratio of isocyanate to acrylic acid, if fluorinated acrylic acid ester is present, is determined by the sum of fluorinated acrylic acid ester and non-fluorinated acrylic acid ester present in the composition.

Instead of treating the fabric or textile, the method of the present invention may be applied to fabric fibers before being assembled into the fabric or textile. Similar water repellency is achieved when fabric or textile products are made from such treated fibers.

The fibers and/or the fabric are preferably selected from polyester, polyamide, acrylate, ultra-high molecular weight polyethylene (e.g. Dyneema, DSM, Netherlands), cotton or aramid or mixtures of two or more thereof. It was found that the water-repellent coating bonded stably and strongly to these types of fabrics. To this end, the fabric preferably comprises polyester and/or polyamide, more preferably polyester.

The treatment in step i) is preferably selected from dipping the fabric in the composition or spraying the composition onto the fabric. Soaking means that the fabric is immersed in the composition. Although soaking is preferred, spraying is a very attractive home appliance, in which the fabric can be sprayed from an aerosol containing the composition and the heat treatment can then be carried out by ironing. In an industrial setting, the treated fabric is preferably soaked and then padded to remove superfluous liquid composition.

In another aspect, the present invention relates to a composition for imparting sustained water repellency to a woven or nonwoven fabric as described above.

In another aspect, the invention relates to the composition, particularly to fibers, textiles or non-woven fabrics as described in this disclosure that have been treated with the composition as described in this disclosure.

The invention will now be further explained by examples and drawings, which show a possible industrial setting for the method of the invention.
The arrows reflect the transport direction of the fabric 1 guided by the guide rollers 2. The process is continuous, i.e. without interruption. The fabric (1) is placed in a bath (3) containing the composition (4) of the present invention. After leaving the bath 3, the fabric 4 passes through two padding rolls 5, which squeeze out excess liquid composition from the fabric. The fabric is dried with hot air in a drying chamber (6), where the temperature is, for example, 130°C, and eventually (the fabric) enters a heating chamber, where the temperature is, for example, 160°C. It is °C.

examples

water repellency

Samples of PES 1 fabric 135 g/m ² and PES 2 fabric 190 g/m ² (MB Sportswear, Eindhoven Netherlands) were washed 100 times according to method ISO 6330 3G or 4H. After washing, its water repellency is measured by the ISO 4920 (version 2012-12) spray method.

Commercial Wash Cycle:

Use a commercial washing machine of type Miele Twindos (Germany) using the program Express 2.0, use detergent Color Reus extra strong against stains, extra clean (Henkel) ), Germany), the water repellency after 120 washes is measured using the ISO 4920 spray method. The specifications of the program and the composition of the detergent are given in Table 1 and Table 2, respectively.

Table 1: Wash program laundry time 6 minutes rinse time 14 minutes Pumping time 14 minutes Spinning time 1 min wash cycle time 27 minutes load 2 to 3 kg temperature 30°C

Table 2: Detergent ingredients Anionic surfactants (5 to 15%) Soap (< 5%) Nonionic surfactants phoshonates perfumes hexl cynnamal preservatives methylisothiazolinone benzisothiazolinone enzymes

oil repellency

Oil repellency is measured according to AATCC118 method 118-1997 after washing the samples 100 times as described above.

sample preparation

Fabric samples were cut to 15 x 15 cm on a reel and soaked in coating emulsion for 1 minute. The uncoated fabric was weighed twice (in duplo). After soaking the coated samples were placed on the rubber sleeve of a manual coating unit (RK prints) for the padding process. With a smooth roller with a weight of 10 kg, excess emulsion was squeezed out by rolling the roller twice over the fabric.

The samples were dried in an oven at 130°C for 3 minutes with forced air ventilation, after which the samples were cured at 160°C for 1 minute. After curing the sample was weighed twice again.

Possible compositions for use in Examples 1 to 8 are given in Table 3. Experiments were performed with the compositions given in Table 4.

In examples 1, 3, 5 to 10 a polyester fabric (PES) ('pique') (MB Sportswear, Eindhoven Netherlands) of 135 g/m ² was used, whereas in examples 2 and 4 195 g/m 2 was used. ² ‘smooth’ fabric (MB Sportswear, Eindhoven, Netherlands) was used.

It was observed that all examples retained their water repellency after a washing cycle and drying in a tumble dryer (AEG Lavatherm Protex plus, AEG, Germany, program setting 'cotton extra dry'). The rating iso 5 was measured for all samples before the first wash and after 100 or 120 washes. A rating of 5 means that no sticking or wetting was observed on the upper surface.

The same result was true in Examples 1 and 3 when the dipping was replaced by spraying and the padding was replaced by tumbling in a tumble dryer as described above. Heating is done by ironing at 150°C (level**) for Example 1 and 200°C (level***) for Example 2, following the fabric manufacturer's ironing instructions. was carried out according to. For these samples, the ISO 5 rating was measured before the first wash and after 100 or 120 washes.

The oil repellency for examples 3, 4, 8 to 10 measured according to AATCC118 was rated 5 to 6 after 100 to 120 washes followed by tumble drying.

However, in the case of line drying, that is, when the dried fabric is not heated, the coating after cross-linking with polyisocyanate is more stable than the results for all coatings after tumble drying. It was observed that, while remaining bonded, coatings without isocyanate (NCO) cross-linking tended to loosen from the fabric after 10 to 12 wash cycles, see Table 5. It was observed that acrylic acid ester:polyisocyanate weight ratio exceeding 30 gave the best bonding.

0 3 6 9 12 15 18 21 24 27 30 Example 1 (no NCO) 5 5 5 5 4 3 3 3 2 2 2 Example 5
(100:60) 5 5 5 5 5 5 5 5 5 5 5 Example 6
(100:30) 5 5 5 5 5 4,5 3 3 3 2 3 Example 7
(100:10) 5 5 5 5 5 4 4,5 4 3 3 2

Claims (10)

As a method for imparting sustained water repellency to a fabric that is woven or non-woven:
i) treating the fabric with an aqueous composition, wherein the composition:
a. an aqueous solvent comprising at least 80 w/w% of water and up to 20 w/w% of a water miscible organic solvent containing at least two OH functional groups,
b. Formula 1: 0.1 to 40 w/w% of acrylic ester, where A ¹ is H or CH ₃ and A ² is C ₁ -C ₃₀ linear or branched, which may have an aliphatic ring or an aromatic ring. Acrylic acid ester, which is a saturated or unsaturated hydrocarbon, and the acrylic acid ester is dissolved, emulsified, or dispersed in the water solvent, and
c. Polyisocyanate containing at least three crosslinkable isocyanate groups
Steps comprising,
ii) heating the treated fabric to 120 to 200°C
Method, including. The method of claim 1, wherein the water-miscible organic solvent is: ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol. Monobutyl Ether Acetate, Propylene Glycol, Propylene Glycol Monomethyl Ether, Propylene Glycol Monoethyl Ether, Propylene Glycol Dimethyl Ether, Dipropylene Glycol, Dipropylene Glycol Monomethyl Ether, Dipropylene Glycol Dimethyl Ether, Dipropylene Glycol Monoethyl Ether, Tri selected from the group consisting of propylene glycol, tripropylene glycol monomethyl ether, polypropylene glycol, and hexylene glycol. The method according to claim 1, wherein the weight ratio of acrylic acid ester:polyisocyanate is 100:5 to 100. The method of claim 1 , wherein the composition further comprises a fluorinated C ₂ -C ₂₀ alkyl compound comprising a terminal acrylic group. A composition for imparting sustained water repellency to textiles or non-woven fabrics, the composition comprising:
a. An aqueous solvent comprising at least 80 w/w% of water and up to 20 w/w% of a water miscible organic solvent containing at least two OH functional groups,
b. Formula 1: 0.1 to 40 w/w% of acrylic ester, where A ¹ is H or CH ₃ and A ² is C ₁ -C ₃₀ linear or branched, which may have an aliphatic ring or an aromatic ring. Acrylic acid ester, which is a saturated or unsaturated hydrocarbon, and the acrylic acid ester is dissolved, emulsified, or dispersed in the water solvent, and
c. Polyisocyanate containing at least three crosslinkable isocyanate groups
A composition containing. The method of claim 5, wherein the water-miscible organic solvent is: ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol. Monobutyl Ether Acetate, Propylene Glycol, Propylene Glycol Monomethyl Ether, Propylene Glycol Monoethyl Ether, Propylene Glycol Dimethyl Ether, Dipropylene Glycol, Dipropylene Glycol Monomethyl Ether, Dipropylene Glycol Dimethyl Ether, Dipropylene Glycol Monoethyl Ether, Tri A composition selected from the group consisting of propylene glycol, tripropylene glycol monomethyl ether, polypropylene glycol, and hexylene glycol. The composition according to claim 5, wherein the weight ratio of acrylic acid ester:polyisocyanate is 100:5 to 100. 6. The composition of claim 5, further comprising a fluorinated C ₂ -C ₂₀ alkyl compound comprising a terminal acrylic group. A fabric treated with the composition of claim 5. A nonwoven fabric treated with the composition of claim 5.