PROCESS FOR TREATING A SUBSTRATE IN ORDER TO IMPROVE THE BEHAVIOUR THEREOF WITH REGARD TO MALODOROUS MOLECULES

Abstract

The present invention provides a method of treating a substrate in order to improve its properties of absorbing malodorous molecules, in particular associated with sweat, the method comprising the following steps: i) preparing an acid aqueous composition comprising at least one organosilane A having at least one hydrolyzable alcoxy group, and at least one main polycarboxylic acid B comprising at least four COOH carboxyl groups or its corresponding anhydride comprising at least four COOCO groups; the weight ratio of said at least one organosilane A over the weight of said at least one main polycarboxylic acid B, lying in the range 0.8 to 1.2; ii) applying said composition on said substrate; and iii) heating said substrate comprising said composition to a temperature higher than or equal to 120 C., preferably higher than or equal to 130 C., in order to polymerize said organosilane A with at least the main polycarboxylic acid B or its corresponding anhydride.

Claims

1. A method of treating a substrate in order to improve its properties of absorbing malodorous molecules wherein said method comprises the following steps: i) preparing an acid aqueous composition comprising at least one organosilane A having at least two hydrolyzable alcoxy groups, and at least one main polycarboxylic acid B comprising at least four COOH carboxyl groups or its corresponding anhydride comprising at least four COOCO groups; the weight ratio of said at least one organosilane A over the weight of said at least one main polycarboxylic acid B, or its corresponding anhydride, lying in the range 0.8 to 1.2; ii) applying said composition on said substrate; and iii) heating said substrate comprising said composition to a temperature higher than or equal to 120 C., in order to polymerize said organosilane A with at least the main polycarboxylic acid B or its corresponding anhydride.

2. The method according to claim 1, wherein the organosilane A comprises at least three alcoxy groups.

3. The method according to claim 1, wherein the organosilane is an epoxyorganosilane.

4. The method according to claim 3, wherein the epoxyorganosilane A is selected from the list comprising: gamma-glycidoxypropyltrimethoxysilane; gamma-glycidoxypropyltriethoxysilane; gamma-glycidoxypropylmethyldimethoxysilane; and gamma-glycidoxypropylmethyldiethoxysilane.

5. The method according to claim 1, wherein the main polycarboxylic acid B is 1, 2, 3, 4 butanetetracarboxylic acid or its corresponding anhydride.

6. The method according to claim 1, wherein the aqueous composition comprises, relative to the total weight (g) of its dry weight (g), at least 20% by weight (g) of said at least one organosilane A.

7. The method according to claim 1, wherein the aqueous composition comprises, relative to the total weight (g) of its dry weight, at least 20% by weight, of said at least one main carboxylic acid B or its corresponding anhydride.

8. The method according to claim 1, wherein the weight gain (g) by said substrate in dry matter of said aqueous composition at the end of the heating step iii) is greater than or equal to 1%.

9. The method according to claim 1, wherein the substrate is made of one or more synthetic materials.

10. The method according to claim 1, wherein the substrate is made of one or more artificial materials.

11. The method according to claim 9, wherein the substrate is a textile element comprising yarns and/or fibers made of said synthetic and/or artificial materials.

12. A method of using an aqueous composition comprising at least one organosilane A having at least one hydrolyzable group and at least one main polycarboxylic acid B comprising at least four COO carboxyl groups, or its corresponding anhydride, for giving odor-absorbing properties to a substrate, the weight ratio of said at least one organosilane A over the weight of said at least one main polycarboxylic acid B, or of its corresponding anhydride, lying in the range 0.8 to 1.2.

13. The method according to claim 12, wherein said substrate is made of one or more synthetic and/or artificial materials, and in that the organosilane A is selected from epoxy trialcoxysilanes and epoxy dialcoxysilanes.

14. A substrate obtainable by performing a method according to claim 1, wherein said substrate presents an odor reduction ratio measured in application of the ISO 17299-3:2014 standard of March 2014 and entitled Textilesdetermination of deodorant propertiesPart 3: gas chromatography method that is greater than or equal to 65%.

15. The substrate according to claim 14, wherein said substrate is a textile element comprising by weight relative to its total weight at least 15% of fiber spun yarns and/or multifilament yarns and/or fibers or a layer of foam, made of one or more synthetic materials.

16. The substrate according to claim 14, wherein said substrate is a textile element comprising by weight relative to its total weight at least 15% of fiber spun yarns and/or multifilament yarns and/or fibers or a layer of foam made of one or more artificial materials.

17. The method according to claim 1, wherein the aqueous composition comprises, relative to the total weight (g) of its dry weight (g), at least 30% by weight (g) of said at least one organosilane A.

18. The method according to claim 1, wherein the aqueous composition comprises, relative to the total weight (g) of its dry weight, at least 30% by weight, of said at least one main carboxylic acid B or its corresponding anhydride.

19. The method according to claim 1, wherein the weight gain (g) by the substrate in dry matter of said aqueous composition at the end of the heating step iii) is greater than or equal to 3%.

20. The method according to claim 10, wherein the substrate is a textile element comprising yarns and/or fibers made of said synthetic materials selected from the list comprising: polyethylene terephthalate; polypropylene; polyethylene; polyamide 6-6; polyamide 6; polyamide 12; polyamide 4-6; poly acrylonitrile; polyacrylic; spandex; polyurethane; polytrimethyleneterephthalate (PTT); polybutylene terephthalate (PBT); or mixtures thereof.

Description

DETAILED DESCRIPTION OF EXAMPLES

[0104] The present invention can be better understood on reading the examples described below and mentioned in non-limiting manner.

[0105] The results of tests 1 to 12 and the aqueous compositions are given in Table 1. The proportions of acid(s) B and of organosilane A are expressed in grams per liter (g/L).

[0106] The last three columns give the odor reduction rates obtained respectively after one, ten, and twenty washes. These rates are measured using the ISO 172299-3:2014 standard of March 2014 and entitled Textilesdetermination of deodorant propertiesPart 3: gas chromatography method. Calculating the reduction rate is specified in point 8 of this standard and corresponds to the difference in the mean area of the hydrogen flame ionization detector (FID) spectrum of the test gas without the textile element (Sb) minus the mean area of the FID peak of the test gas with the textile element (Sm), this difference being taken relative to the area Sb and then multiplied by 100. Thus, values that are negative or zero indicate that there was no reduction in the target gas. The target gas used in the measurements listed below was acetic acid.

[0107] It should be observed that the above-referenced ISO 17299-3:2014 standard dating from March 2014 makes provision for one wash prior to performing measurements of target gas absorption.

[0108] Tests 1 to 11 were performed on undyed washed polyethylene terephthalate (PET) fabrics; only test 10 was performed on a dyed PET fabric.

[0109] For tests 1 to 8, the fabrics were subjected to the following methods: the organosilane A, in particular gamma-glycidoxypropyltrimethoxysilane (GPTMS) was mixed with the acid B and then the volume of the mixture was adjusted so as to obtain 1 liter of water, preferably demineralized water, at ambient temperature, in particular at 30 C., e.g. for 60 minutes in step i). Then in a step ii), a sample of PET fabric was subjected to a first pass during which the sample of fabric was padded and then squeezed (pressure of 4 bars at a travel speed of 1 meter per minute). Step ii) further comprised a second pass identical to the first pass. The sample of fabric impregnated with the aqueous composition was then subjected to a drying step for 3 minutes at 110 C. followed by a heating step iii) during which the sample of fabric was subjected to a temperature of 170 C. for 5 minutes. Depending on the concentration of organosilane A and of acid B, and on the viscosity of the aqueous composition (which can be adjusted by thickening agents, e.g. based on carboxymethylcellulose), a single pass might suffice.

[0110] Test 9 differs from tests 1 to 8 in that it had only one pass in step ii), and did not include the drying step.

[0111] Test 10 differs from tests 1 to 8 in that it included a single pass in step ii), it did not include a drying step, and in that in step iii), the temperature was 190 C. for 5 minutes.

[0112] Test 11 differs from tests 1 to 9 in that it had only one pass in step ii), it did not have a drying step, and in that, in step iii), the temperature was 190 C. for 9 minutes.

[0113] For tests 1 to 11, the pH of the aqueous composition was greater than or equal to 1.5 and less than or equal to 2.5.

[0114] The samples of treated fabric were subjected to at least one wash.

[0115] Preferably, washing was performed in conventional manner in a washing machine for at least 15 minutes, optionally using a washing powder/liquid.

[0116] On reading Table 1, it can be seen that when the aqueous composition had only the organosilane A, the reduction rate was very low after one wash, and down to zero after more than ten washes.

[0117] When the aqueous composition comprised only formic acid, oxalic acid, or succinic acid, the reduction rates were zero or extremely low. When citric acid, which is a triacid, was added to the aqueous composition, the reduction rate exceeded 50% after one and ten washes, but was zero after twenty washes. The coating that is formed is thus not long-lasting on a textile element that, in use, in particular for regularly practicing sports, will be washed many times. Furthermore, the inventors have observed by olfactory tests performed with a panel of 12 experts that they perceive an odor reduction for a reduction rate of at least 65%; the reduction is clearly perceived by users for a reduction above 80%, and better still for a reduction above 90%. It has been observed in particular that test 9 enables odors to be reduced as effectively as for a textile element made of cotton, with a reduction of odors that is much better than that had been observed for a fabric made of non-treated polyester.

TABLE-US-00001 TABLE 1 Measured Measured Measured odor odor odor Formic reduction reduction reduction acid Citric Oxalic Succinic ratio (%) ratio (%) ratio (%) GPTMS BTCA (85%) acid acid acid after 1 after 10 after 20 Test (g/L) (g/L) (g/L) (g/L) (g/L) (g/L) wash washes washes 1 40 40 85.07 68.3 66.75 2 20 19.24 3 3 40 40 3 28 2 4 40 20 0 31 40 5 40 60 2 3 2 6 40 20 31 58 58 2 7 40 20 40 37 54 20 8 40 20 15 11 23 27 9 40 40 93 90 72 10 60 60 68 94 94 11 40 40 58 87 84

[0118] Table 2 below gives the reduction rates obtained for an aqueous composition comprising 3-aminopropyltriethoxysilane (APTS) as organosilane A. In Table 2, the reduction rate was measured in the same manner as for Table 1. In performing the method of the invention, test 12 differs from tests 1 to 8 only in that it had only one pass in step ii), that the organosilane A was APTS, and that it did not include a drying step.

[0119] The reduction rate obtained was good after a first wash, however it can be seen that this reduction rate collapsed after ten washes.

TABLE-US-00002 TABLE 2 Measured Measured Measured odor odor odor reduction reduction reduction ratio (%) ratio (%) ratio (%) APTS BTCA after after after Test (g/L) (g/L) 1 wash 10 washes 20 washes 12 40 40 97 38 28

[0120] In conclusion, it can thus be seen from the results of Tables 1 and 2 that the combination of organosilane A with a polycarboxylic acid having at least four COOH carboxyl groups makes it possible to achieve reduction rates greater than 80%, or indeed greater than 90%, even after ten or twenty washes. The coating of the invention formed on the textile element serves to reduce odors very significantly and in a manner that is clearly perceptible for the user, said coating remaining effective even after many washes, in particular when it is an epoxyorganosilane.

Measuring the Dynamic Liquid Transport Properties of a Polyester (PET) Fabric Given Hydrophilic Treatment and then Treated by the Method of the Invention

[0121] This method consisted in placing a sample of polyester fabric between two moisture sensors and depositing a drop of a liquid on one of the faces of the fabric and then measuring the speed with which the drop passes through the fabric. The drop of liquid had conductivity of the order of 16 millisiemens (mS) (distilled water mixed with sodium chloride). The test was performed at ambient temperature, in particular at 20 C.2 C., and with relative humidity of 65%4% at atmospheric pressure.

[0122] The tested polyester fabrics were subjected to treatment to make them hydrophilic, which treatment is conventional and known to the person skilled in the art.

[0123] A controlled polyester fabric that was not treated by the method of the invention, presenting a weight per square meter of 130 g/m.sup.2, and a thickness of 0.57 mm1.75%, was subjected to at least one wash and presented a speed of passage for the drop of water from one face of the fabric to the other of 5.2 millimeters per second (mm/s)22%.

[0124] A polyester fabric treated using the method of the invention (the composition of test 10) having a weight per square meter of 130 g/m.sup.2, and a thickness of 0.57 mm1.75%, and that had been subjected to at least one wash, presented a speed of travel for the drop of water from one face of the fabric to the other of 6.8 mm/s22%.

[0125] Advantageously, the method of the invention conferring odor-absorbing properties on a substrate does not modify its initial water absorption properties.

[0126] The treatment of the invention thus cannot be considered as being equivalent to a hydrophobic treatment, since it has no repulsive effect relative to water.