ITMC20070223A1 - TNT CLOTH ABLE TO SIMULTANEOUSLY ABSORB OUT OF DIRT PARTICLES AND DETERGENT COLORINGS OF DIFFERENT CHEMICAL NATURE DURING WASHING DOMESTIC WASHES. - Google Patents

Description

DESCRIPTION

accompanying a patent application for an industrial invention entitled:

"TNT CLOTH ABLE TO ABSORB PARTICLES OF DIRT AND FUGITIVE DYES OF DIFFERENT CHEMICAL NATURE AT THE SAME TIME DURING DOMESTIC WASHING IN THE WASHING MACHINE".

TEXT OF THE DESCRIPTION

The present invention refers to a non-woven fabric (TNT) designed to be used during domestic washing cycles in the washing machine. This cloth consists of a non-woven fabric support containing a polymeric matrix comprising chemical functionalities that give it a) the ability to absorb the particles of fugitive dyes that are loosely bound on the fabric that are released during the washing of dyed garments in the washing machine and that could stain the other garments present, without allowing them to be redeposited on the fabrics. This action is carried out on all the different families of dyes that can be released from the garments during washing: direct and reactive dyes used in the dyeing of cotton, dispersed for polyester, acids for nylon and silk, pre-metallic for wool, and b) the ability to absorb, during the aforementioned washing cycle in the washing machine, also the dirt particles present in the washing water and prevent their redeposition on the garments subject to washing. This is achieved by using a particular aqueous dispersion of clay particles, a material well known for its adsorbing properties in particular of oils and fats.

It is known and commercially available supports for use in domestic washing machines generally made of cellulose-based but also synthetic non-woven fabric materials, containing molecules with specific functions such as whiteners, detergents, oxidizing agents, color binders, descalers , optical brighteners or fabric softeners. The molecules having the aforementioned functions are made to adhere to the surface of the material with physical impregnation but also chemical anchoring processes, and once placed in the aqueous washing solution in the washing machine, the functional molecules more or less firmly anchored to the material of the TNT cloth can be released to carry out their action in solution or remain anchored to the support.

In particular, cationic polymers are used as binders of the fugitive color (USP 3694364, USP 4065257, USP 4380353), since the majority of dyes have an anionic charge. These molecules are not selective and can interact with other anionic molecules present in higher concentration in the washing solution such as those of many detergents, with optical bleaches and lastly, perhaps the most important aspect, they can contribute if solubilized because they are not perfectly anchored to the fabric of the support to fix the molecules of fugitive color on articles or garments subject to washing given the high affinity of cationic agents for fabrics, especially cotton.

The action of these cationic polymers on fugitive colored particles having different chemical origins is also not equally effective. In fact, the ability to bind the color can be very variable depending on the particular family of fugitive dyes. For example, in the case of acrylic fibers that are dyed with positively charged basic dyes, there would be very little affinity between any fugitive dye molecules and cationic agents due to the onset of electrostatic repulsion phenomena.

The present invention describes the preparation of a non-woven cloth, preferably viscose or lyocell by virtue of a higher mechanical resistance than cotton, comprising a synthetic matrix consisting of an acrylic copolymer and specific chemical functionalities capable of giving the the aforementioned cloth the ability to absorb dirt particles and at the same time also any molecules of fugitive dyes present in a normal domestic washing cycle in the washing machine, avoiding their redeposition on other garments or articles subject to the same washing cycle. the aforementioned non-woven fabric is very effective on fugitive dyes belonging to all the different families of dyes: reactive and direct for cotton, dispersed for polyester, acids for nylon and premetallized acids for wool. This is due to the chemical nature of the chemical functionalities anchored on the TNT cloth in order to inhibit the fugitive molecules of color, based on polyvinylpyrrolidone-covinylimidazole copolymers. These functionalities are present in the formulations of many detergents (DE 2814287, EP 372291, EP 327927, DE4027832), they have no cationic charge and therefore do not interact preferentially with the anionic dyes alone but favor the establishment of an aromatic-aromatic interaction with the component for the aromatic note present on almost all dye molecules, regardless of the family they belong to. The absence of positive charge also minimizes the risk of possible redeposition on other tissues of possibly solubilized polymeric particles which, unlike cationic polymers, do not show any affinity for the tissues.

The action of the TNT cloth on dirt particles is carried out thanks to the anchoring of clay particles, a material with a strong adsorbing capacity with a high affinity for lipid molecules. The clay as a sedimentable material must be kept dispersed in solution in order to obtain its homogeneous deposition on the TNT cloth. This is achieved through the use of an aqueous dispersion containing viscosifying and surfactant principles based on C-11-14 iso alcohols rich in C13 and tridecyl alcohol ethos silate, capable of preventing the sedimentation of clay particles. Once deposited on the substrate, the clayey mineral particles do not have a specific chemical bond with the non-woven fabric and perform their action in a dual way: both remaining partially trapped in the material of the TNT cloth and being released from the cloth itself, to perform in the washing solution and no longer on the surface of the TNT cloth their action of adsorption of dirt particles. Since the complex formed in the washing solution between the clay particles and the dirt particles has no affinity for the fabrics, there is no danger of redeposition of the dirt particles on garments or other items subject to washing. The idea behind the present invention provides for the realization of a non-woven fabric with a substantially known process through the deposition, and cohesion of a web of discontinuous fibers through a chemical process, preferably of viscose or lyocell by virtue of a higher mechanical resistance. compared to cotton, of a foam that is formed starting from a solution containing as a dry substance:

- 10 to 80 parts of an acrylic polymer, preferably 55%,

- from 1 to 10 parts of an anionic or cationic surfactant, preferably 2%

- from 1 to 50 parts of a solution of a mixture of copolymers based on polyvinylpyrrolidone-covinylimidazole, preferably 20%,

- from 1 to 50 parts of a solution containing an anchoring polymer of epichlorohydrin derivation, preferably 10%, containing specific functionalities capable of binding the polymer both to the cellulose of the substrate and to the copolymer based on polyvinylpyrrolidone-vinylimidazole

- from 1 to 30 parts, preferably 10%, of an aqueous dispersion of clay particles containing ethoxylated alcohols - from 1 to 5% of wetting substance, preferably 3%, based on tridecyl alcohol with a low degree of ethoxylation, containing from 1 to 10 moles of ethylene oxide, preferably 6 moles, in order to improve the wettability of the TNT cloth in order to accelerate the fixation process on the cloth of the molecules of fugitive dyes and dirt during washing cycles in the washing machine .

The foam has a homogeneous appearance and is deposited with special equipment evenly over the entire surface of the non-woven fabric during the transport of the fiber web, it is then compressed through squeezing rollers that compact the material and force the foam itself to penetrate the pores. of the non-woven fabric.

After squeezing, this material is conveyed into a special oven containing the aforementioned foam, it is treated at a temperature between 120 and 180 ° C, preferably 160 ° C, for a time between 45 seconds and 90 seconds, preferably 60 seconds, in order to to make the final compaction take place through the cross-linking of the acrylic polymer and the anchoring reaction of the molecules on the non-woven fabric.

The TNT cloth thus made has a weight between 60 and 90 g / m, preferably between 70 and 80 g / m.

It is also possible to operate with a second substantially known process called padding.

In this case, the cellulose-based non-woven fabric containing only the acrylic polymer and the surfactant substance is initially prepared with the methodology described above. Subsequently, in a second operational phase, the roll material is subjected to an impregnation operation, which consists of dragging the fabric onto special rollers which, passing inside a metal plate, absorbs an aqueous solution consisting of:

- from 5 to 20 parts of a mixture of copolymers based on polyvinylpyrrolidone-covinylimidazole, preferably 5%, able to interact with the aromatic component present in almost all the dye families and in particular the azoderivatives,

- from 5 to 10 parts of an anchoring polymer of epichlorohydrin derivation, preferably 3%, containing specific functionalities capable of binding the anchoring molecule both to the cellulose of the substrate and to the copolymer based on polyvinylpyrrolidone vinylimidazole

- from 5 to 10 parts, preferably 2%, of an aqueous dispersion of clay particles capable of absorbing dirt particles with a greasy matrix.

- from 0.1 to 1% of wetting substance, preferably 0.2%, based on tridecyl alcohol with a low degree of ethoxylation, containing from 1 to 10 moles of ethylene oxide, preferably 6 moles in order to improve the wettability of the TNT cloth in order to accelerate the fixation process on the cloth of the molecules of fugitive dyes and dirt during washing cycles in the washing machine.

The fabric impregnated with solution after passing through the metal plate is subsequently squeezed operating continuously in a controlled manner to obtain an absorption by weight of the solution with respect to the weight of the non-woven fabric which varies from 50 to 150%, preferably 100%. The fabric is then continuously subjected to a subsequent combined mechanical and thermal stabilization treatment with a "stenter" type equipment, treatment carried out at temperatures ranging from 100 to 160 ° C, preferably 130 ° C, for a time ranging from 10 and 30 minutes, preferably 20 minutes. In this way, by the action of heat, the anchoring reaction of the functional molecules on the non-woven fabric substrate is completed. The TNT cloth thus made has a weight between 60 and 90 g / m, preferably between 70 and 80 g / m.

The wet mechanical resistance of the non-woven cloth is an important parameter to determine its suitability for use in the washing machine. In fact, the nonwoven cloth must remain cohesive and not flake off during the washing cycle, which can actually occur on non-woven fabrics placed in prolonged contact with aqueous solutions when their wet resistance is low. The nonwoven cloth described in the present invention has tensile strength values both in the longitudinal and transversal directions, with both the processes described above, not less than 1.5 Kgf, preferably not less than 1.7 Kgf in the longitudinal direction and 2 Kgf transversely when measured with an axial dynamometer.

Claims (2)

CLAIMS 1) Disposable nonwoven cloth to be used during domestic washing cycles in the washing machine consisting of one or more layers of non-woven viscose or lyocell fabric and containing an acrylic copolymer. 2) Nonwoven cloth according to claim 1 characterized in that organic polymeric substances based on polyvinylpyrrolidonecovinylimidazole are stably adhered to it as binders of the fugitive color in a percentage between 1 and 10% 3) TNT cloth according to claim 1 where the anchoring of the polymers as per claim 2 is carried out thanks to the use of organic substances of the epichlorohydrin type in a percentage between 1 and 10% 4) TNT cloth according to claim 1, characterized in that clay particles in a percentage ranging from 1 to 10% are made to adhere to it in order to bind the dirt particles. 5) TNT cloth according to claim 1 where the adhesion to the cellulosic substrate of the molecules according to claims 2, 3 and 4 is carried out by mixing with the acrylic copolymer and forming a foam, deposition and squeezing of the foam on the cellulosic substrate and subsequent crosslinking of polymers by the action of temperature. 6) TNT cloth according to claim 1 where the adhesion to the cellulosic substrate of the molecules according to claims 2, 3 and 4 is carried out by absorbing and squeezing an aqueous solution containing said molecules and subsequent fixation on the substrate by the action of temperature. 7) TNT cloth according to claim 1, containing the functional groups as per claims 2 and 3, where the inhibitory action of the fugitive dye is carried out on different families of dyes: direct and reactive used for cotton, dispersed for polyester, acids for nylon and silk, premetallized acids for wool, bases for acrylic fibers 8) Nonwoven cloth according to claim 1, containing the functional groups according to claims 2, 3 and 4, where the wet mechanical resistance is greater than 1 Kgf both in the longitudinal and transversal directions.