Patent Application
20190049336
The present invention relates to a functionalized textile substrate with cyclodextrins and/or cyclodextrin derivatives and water- and/or oil-repellent agents, which combines the water- and/or oil-repellent functionality with odor-absorbing properties.
In the textile field, and in particular in the field of fabrics for decorating interior, functionalized technical fabrics are used giving the fiber or textile particular properties that improve or integrate those of the material, hence obtaining new possibilities for the use of traditional materials.
Cyclodextrins and their derivatives may be used in the textile sector for the surface functionalization of fabrics.
Cyclodextrins are cyclic oligosaccharides comprising a number of D-glucopyranose units that generally varies from 6 to 8 (α-, β- and γ-cyclodextrin, respectively). Cyclodextrins preferably have a truncoconical spatial conformation wherein the hydroxyl functions are placed outside the ring, making the cyclodextrin molecules soluble in an aqueous environment.
Instead, the inside of the molecule is comprised of a hydrophobic cavity able to include/host apolar or not very polar substances, which are normally insoluble in water.
The three classes of cyclodextrins (α, β and γ) differ from one another due to the size of the ring and therefore the size of the cavity and their solubility in water.
Cyclodextrins may be modified according to different methods, producing different cyclodextrin derivatives: one or more hydrogen atoms of the hydroxyls may be substituted obtaining, for example, esters and ethers; or one or more —CH2OH groups may be oxidized to carboxyl groups.
The possibility to incorporate cyclodextrins in fabrics without altering their hosting cavities has enabled the chelating properties of cyclodextrins to be exploited in the textile field; the reactive derivatives of cyclodextrins have been used in the textile field for treating fibres or fabrics to prevent or reduce bad smells due to sweating.
In a further embodiment, the reactive derivatives of cyclodextrins have been used as carriers for organic molecules of various kinds, e.g. fragrances and perfumes, or substances with antimicrobial activity.
Reactive cyclodextrins and their derivatives can be fixed to fabrics directly by impregnating the textile, as described for example in patent EP1841315, or by incorporating the cyclodextrins in a thermoplastic polymer matrix that is transferred onto the surface of the textile as described in Italian patent 1327881.
In this context, the object of the present invention is to propose a functionalized textile substrate that has odor-absorbing properties and/or that emits odorous substances, in particular perfumes or fragrances, in combination with water- and/or oil-repellent properties.
The specified object is substantially reached by a functionalized textile substrate comprising the technical characteristics disclosed in one or more of the appended claims.
The present invention therefore relates to a functionalized textile substrate comprising:
Preferably, the at least one cyclic oligosaccharide may be chosen from α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, α-cyclodextrin derivatives, β-cyclodextrin derivatives, γ-cyclodextrin derivatives and mixtures thereof. Cyclodextrin derivatives with high water solubility are particularly useful for the realization of the present invention.
More preferably, the at least one cyclic oligosaccharide may be a β-cyclodextrin derivative having formula
wherein
R may be independently chosen from H and a linear or branched C1-05 alkyl group, optionally substituted with hydroxyl, carboxyl and/or phenyl groups, and mixtures thereof.
According to one embodiment, the at least one cyclic oligosaccharide may be (2-hydroxypropyl)-β-cyclodextrin (CAS: 128446-35-5), preferably with a degree of molar substitution comprised between 0.6 and 1.0 (i.e. 0.6-1.0 moles of 2-hydroxypropyl units per mole of glucopyranose).
According to one embodiment, the functionalized textile substrate may comprise 1-10 g/m2, preferably 3-7 g/m2 of at least one cyclic oligosaccharide as described above.
Cyclodextrins and cyclodextrin derivatives useful for the realization of the invention are available on the market.
The term “water- and/or oil-repellent agent” refers in the present description and in the appended claims to a compound or composition able to make the textile substrate to which it is applied water- and/or oil-repellent.
The water-repellency is obtained by reducing the surface energy of the textile substrate so that the water collects in compact drops on the surface, without saturating the substrate. This result may be obtained with numerous types of coatings. Preferably, the at least one water- and/or oil-repellent agent is chosen from fluorocarbon resins, silicone resins, dendrimer resins and mixtures thereof.
Fluorocarbons offer the highest level of water-repellency and are not very permeable to oils, therefore they are commonly used in resins and in water-repellent and oil-repellent coatings. Furthermore, this type of treatment does not alter the aesthetic characteristics of the fabrics or their pleasant feel. According to one variant, the at least one water- and/or oil-repellent agent may be a fluorocarbon resin normally used in the textile field to give textile substrates water- and oil-repellent properties.
Said fluorescent resins are generally aqueous dispersions of fluoropolymers based on C6 or C8 or fluorocarbon compounds containing 6/8 carbon atoms.
According to one embodiment, the functionalized textile substrate may comprise from 5 to 50, preferably from 10 to 30 g/m2, more preferably about 15 g/m2, of at least one water- and/or oil-repellent agent as described above.
The functionalized textile substrate according to the present invention may be produced during the finishing operations on the substrate using the equipment normally found in a company in the textile manufacturing sector, through the immersion of the substrate itself in at least one bath comprising the at least one cyclic oligosaccharide and/or the at least one water- and/or oil-repellent agents (padding) or through spraying, both followed by the heat setting of the water- and/or oil-repellent agent.
According to a first variant, the functionalized textile substrate may be produced in a process, typically a continuous process, which comprises:
By applying the cyclic oligosaccharide and the water- and/or oil-repellent agent through padding in a single step and heat setting them in the stenter, it may happen that the water- and/or oil-repellent agent forms a film that includes the cyclic oligosaccharide within it. In this way, it is still physically anchored to the textile substrate but the film may obstruct a part of the cyclic oligosaccharide cavity, hence limiting its odor capturing effect. In fact, a too low percentage of cyclic oligosaccharide available on the surface of the textile substrate leads to lack of functioning or to a strong limitation of the odor capturing power of the finished product.
It has been determined experimentally that to have a perceptible odor absorbing effect, at least 25%, preferably at least 30%, of the cyclic oligosaccharide present on the functionalized substrate must be available for complexation.
In a second variant, the finishing process for the production of a functionalized textile substrate may take place in a double step, in a semi-continuous process comprising:
By appropriately varying the feeding speed of the pad and/or the squeezing pressure of the rollers it is possible to obtain pick-up values comprised between 60% and 90%, preferably between 75% and 90%.
Preferably, in both variants of the padding process described above, the concentration of the at least one cyclic oligosaccharide in the interval 2-20 g/l, more preferably in the interval 5-15 g/l, and the concentration of the at least one water- and/or oil-repellent agent, may be comprised within the interval 20-40 g/l, more preferably in the interval 25-35 g/l.
The pad impregnation of the textile substrate allows both surfaces of the substrate to be functionalized in a substantially uniform way.
According to an alternative, an aqueous solution comprising the at least one water- and/or oil-repellent agent, the at least one cyclic oligosaccharide and optionally, but preferably, also a surfactant may be sprayed onto at least one portion of at least one surface of the textile substrate in appropriate spraying cabins. The aqueous solution used may have a concentration of 15-80 g/l.
After spraying, the substrate is subjected to heat setting in a stenter at the cross-linking temperature of the water- and/or oil-repellent agent.
According to this variant, a functionalized textile substrate may be obtained in which the functionalization, i.e. the at least one cyclic oligosaccharide and the at least one water- and/or oil-repellent agent is present on at least one portion of at least one surface of the substrate.
In order for the water- and/or oil-repellent agent not to enter the cavity of the cyclic oligosaccharide compromising the odor-absorbing and complexing capacity against the odorous substances, in the preparation of the functionalized textile substrate according to the invention, water- and/or oil-repellent agents are preferably used that are able to form aqueous dispersions of particles having significantly higher dimensions than the dimensions of the cyclic oligosaccharide molecules; preferably the dimensions of the particles of water- and/or oil-repellent particles may be at least 20 times higher than the dimensions of the cyclic oligosaccharide.
Thanks to the heat setting of the water- and/or oil-repellent agent the molecules of cyclic oligosaccharide are fixed in a stable way to the textile substrate, which maintains the functionalization, i.e. the odor-absorbing and water- and/or oil-repellent characteristics, for long periods, even when subjected to washing. The odor-absorbing property is further particularly advantageous since it allows the functionalized textile substrate to absorb or emit odors/fragrances during use.
Furthermore, cyclic oligosaccharides that do not have any affinity for fibers can also be anchored in a stable way to the substrate for the realization of the present invention.
According to a further variant, the functionalized textile substrate further also comprises at least one odorous substance complexed to said at least one cyclic oligosaccharide.
The term “odorous substance” refers in the present description and in the appended claims to a substance that induces a typical sensation, pleasant or unpleasant, for the human sense of smell.
The cyclic oligosaccharides according to the invention may form inclusion complexes with molecules that have appropriate dimensions: the odorous substance (guest molecule) may be included in the cyclodextrin or in the cyclodextrin derivative (host molecule) without significantly changing the dimensions of the host cavity.
The stability of the complex is measured by the inclusion constant and depends on the structure of the molecule in question, which must have at least one hydrophobic pendant or portion. Preferably, the molar ratio of cyclic oligosaccharide/odorous substance may be 2:1 or 1:1.
Illustrative and non-limitative examples of odorous substances that can be used in the present invention may be N,N-diethyl-m-toluamide, (R)-(+)-limonene, vanillin, menthol, terpineol, pinene and mixtures thereof.
The functionalized textile support according to this further variant may be produced according to any one of the methods previously described, wherein the textile substrate is treated with at least one cyclic oligosaccharide complexed to an odorous substance.
The cyclic oligosaccharide/odorous substance inclusion complex may be produced by dissolving a cyclic oligosaccharide in water and then adding appropriate quantities of odorous substance under agitation.
Alternatively, the cyclic oligosaccharide/odorous substance inclusion complex may be formed on the textile already functionalized with the cyclic oligosaccharide, before or after the water- and/or oil-repellent agent heat setting step.
Since on the surface of the functionalized textile substrate a balance is established between the free form of the cyclic oligosaccharide and the complexed form, the guest molecule (odorous substance) is gradually emitted into the environment.
Also, since the host cavity of the cyclic oligosaccharide is not substantially modified by the formation of the inclusion complex, it is possible to “recharge” the functionalized textile substrate with new odorous substances, for example, through the application of sprays of solutions containing fragrances or perfumes.
The term “textile substrate” refers in the present description and appended claims to a textile with a warp and weft, knitted textile, a yarn, a wick or a non-woven textile. Therefore, the present invention relates to a functionalized textile substrate according to the above description, wherein said substrate is chosen from a textile, a yarn and a non-woven textile.
Furthermore, the functionalized substrate according to the invention may be realised with fibers chosen from natural fibers, synthetic fibers (techno-fibers made from synthesized fibers), artificial fibers (techno-fibers made from natural polymers) and mixtures thereof.
The natural fibers useful for the realization of the present invention include, for example, cotton, linen, hemp, jute, wool and silk.
The synthetic fibers useful for the realization of the present invention include, for example, acrylic, polyamide, polyester, polypropylene, polyurethane and teflon (Gore-tex).
The artificial fibers useful for the realization of the present invention include, for example, rayon, lyocell and viscose.
The functionalized textile substrate according to the present invention may be made of 100% synthetic fibers. However, preferably, the functionalized substrate may comprise up to 100% natural fibers, preferably cotton.
According to a preferred variant, the functionalized textile substrate according to the invention may be a textile substrate for rugs, carpets, curtains, cushions, textile substrates for sofas and armchairs, beds, furniture for the automobile and transport sector, for the clothing sector, for technical uses, such as filtering septa.
The invention is further illustrated below through examples of embodiments that have an illustrative and non-limitative purpose.
Measurement Methods
Dimensions of the Particles of Water- and/or Oil-Repellent Agent and the Molecules of Cyclic Oligosaccharide:
Dynamic Light Scattering (DLS)
Pick-Up:
the pick-up of the textile was calculated using the following formula
after weighing the pad before and after the impregnation treatment.
Theoretical Quantity of Cyclodextrin on the Textile:
calculated using the formula
wherein (% CONCCD) is the concentration of the cyclodextrin in the padding bath, expressed as a percentage.
Water-Repellency:
test with water/isopropanol solutions (3M Water Repellency Test II, water/alcohol test; INDA Standard Test 80).
Oil-Repellency:
method for resistance to hydrocarbons (AATCC Standard Test Method 118-1984 e INDA Standard Test 80.7-92).
Both tests are based on the visual observation of the resistance to the penetration of drops of various liquids, which cover a given interval of surface tensions (y1) deposited on the textile.
The repellency value corresponds to the value assigned to the first liquid, in y1 decreasing order, which does not wet the surface, i.e. is not absorbed within a determined time interval (about 5 seconds).
The standard liquids used are listed in the tables below with the corresponding surface tension values.
Available Cyclodextrin:
the test is based on the decoloration of a phenolphthalein solution with a known titre when placed in contact with a cyclodextrin: when an aqueous solution of phenolphthalein at pH >9 is placed in contact with a textile treated with cyclodextrin, an inclusion complex is formed between the molecule of phenolphthalein and the cyclodextrin. The formation of the complex causes the discoloring of the solution; the variation of the intensity of the fuchsia coloring may be connected with the percentage of cyclodextrin available for the formation of the complex. The percentage of available cyclodextrin is calculated by immersing a 10×10 cm sample of textile in a bath containing a known concentration (5-7 mg/l) of aqueous solution of phenolphthalein buffered to pH >9.0 (magenta coloring). The textile is kept immersed in the bath, under agitation, at ambient temperature for 1 hour. Subsequently, the textile is removed from the bath and the phenolphthalein solution is analyzed using a UV-VIS spectrophotometer at a wavelength of 550 nm.
To determine the concentration of the phenolphthalein in solution, a calibration curve of the absorbency values as a function of the concentration having the equation y=24060x (R2=1) was constructed, starting from phenolphthalein solutions with a known titre (concentration in the range 10−7-10−5 mol/l).
The quantity of available cyclodextrin is calculated according to the equation:
wherein
ABS(std) is the absorbency of a solution placed in contact with a textile substrate containing no cyclodextrin;
ABS(test) is the absorbency of a solution placed in contact with the functionalized textile substrate.
The percentage of available cyclodextrin is expressed as the quantity of available cyclodextrin with respect to the initial quantity of cyclodextrin.
Odor-Absorbing Property:
the odor-absorbing property of the textile is assessed based on a sensory analysis, placing a 20×30 cm sample of the functionalized textile substrate in a sealable chamber inside which a solution with a known concentration of the following odorous substances is present on an 8 cm diameter watch glass:
A reference sample (non-functionalized textile substrate) is placed in a same sealable chamber in which the same odorous substance is diffused. Both chambers are sealed and the air inside the chamber is placed in movement by appropriate fans (diameter 70 mm; speed: 1000 rpm).
After 15 minutes an aliquot of the air contained inside each chamber is taken out and given to a panel of 10 assessors to smell; the panel attributes a numerical value comprised between 0 and 3 to the sample of air (test) based on the criteria indicated below, to be compared with the reference sample (std).
A decorating interior textile having the following characteristics:
Composition: 60% cotton/40% polyester
Weight: 800 g/m
was impregnated in a continuous padding process (speed of the pad: 10 m/min.; squeezing pressure: 6 bar) with an aqueous solution comprising:
30 g/l water- and oil-repellent agent (Nanoprove FC2—CHT Bezema);
10 g/l (2-hydroxypropyl)-β-cyclodextrin;
0.1-0.5 g/l surfactant (dodecylbenzenesulfonic acid—Sigma Aldrich).
The sample was then subjected to heat setting in a stenter at 130° C. for about 3 minutes.
The characteristics of the water- and oil-repellent agent and the cyclodextrin derivative used are shown in Table 1.
Table 2 shows the results of the drop tests for checking the water- and oil-repellency and % of available cyclodextrin, performed on textile samples (20×30 cm), and absorption of odorous substances, performed according to the methods described above.
Table 2 shows as a comparison the results of the drop test for checking the water- and oil-repellency, % of available cyclodextrin and absorption of odorous substances performed on the textile used in the previous examples, padded in the same conditions described in example 1 using a bath containing an aqueous solution of fluorocarbon resin Nanoprove FC2 (conc. 30 g/l) free from cyclodextrin.
The textile used in example 1 was treated with a semi-continuous process consisting of:
Table 3 shows the results of the drop tests for checking the water- and oil-repellency and % of available cyclodextrin, performed on textile samples (20×30 cm), and absorption of odorous substances, performed according to the methods described above.
Table 3 shows as a comparison the results of the drop test for checking the water- and oil-repellency, % of available cyclodextrin and absorption of odorous substances performed on the textile used in the previous examples, padded in the same conditions described in example 2 using only one bath containing an aqueous solution of fluorocarbon resin Nanoprove FC2 (conc. 30 g/l) free from cyclodextrin.
The “drop test” highlights that the presence of (2-hydroxypropyl)-β-cyclodextrin does not clearly change the water- and oil-repellency properties that the resin used gives to the textile, either when the functionalization of the substrate takes place in a single step, or when the cyclodextrin is applied in a second padding of the textile.
After the heat setting of the resin, about ⅓ of the cyclodextrin potentially available remains available to perform an odor-absorbing function.
The percentage value of cyclodextrin available to perform an odor-absorbing function obtained with the double step finishing is absolutely comparable with the value obtained with the single step finishing.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2017/050178 | 2/12/2017 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62310825 | Mar 2016 | US | |
| 62294322 | Feb 2016 | US |
