Flocked material and process to produce it

Abstract

The present invention concerns a process for the preparation of a flocked material for coating surfaces and structures such as the interiors of automobiles, objects for interior decorating (walls, sofas, armchairs, etc.), handbags, suitcases or other accessories, covers or cases for weapons, musical instruments or electronic devices, or to make carpets and/or rugs, and that comprises the use of bicomponent fibres of the “island-in-the-sea” type of limited length (microfibres). The process of the invention comprises a step of partial and selective dissolution of the sea component by an alkaline removal agent, which makes it possible to obtain a flocked material characterized by improved resistance to abrasion and a more appealing appearance compared to flocked products of the prior art.

1 . A process for the preparation of a flocked material starting from sea-island bicomponent fibres, comprising the steps of:
 spinning a bicomponent fibre of the “island-in-the-sea” type to produce sea-island bicomponent fibres that contain a sea component and an island component;   cutting the fibre to a length ranging between 0.1 mm and 3 mm;   optionally, dyeing the fibres with coloring agents;   applying an aqueous solution comprising inorganic salts to the fibre to activate the fibre;   applying an adhesive agent onto a backing layer made of fabric or non-woven fabric;   depositing the cut fibre on the backing layer coated with the adhesive agent by means of electrostatic deposition to orient the fibres;   drying and optionally reticulating the adhesive agent;   optionally, removing excess fibres;   optionally, applying a layer of a removable resin at the base of the fibres to protect the fibre base;   at least partially removing the sea component of the fibres by applying a removal agent that has a viscosity ranging between 300 mPa·s and 100,000 mPa·s to provide a flocked material; and   optionally, dyeing the flocked material.   
     
     
         2 . The process according to  claim 1 , wherein the island component of the bicomponent fibre is selected from the group consisting of modified polyesters, cationic polyesters, polyamides (PA), polyethylene (PE), polypropylene (PP), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and combinations thereof. 
     
     
         3 . The process according to  claim 1 , wherein the sea component of the bicomponent fibre is selected from the group consisting of nylon 6,6, co-polyester with a different content of monomer soluble in alkali, and modified polyolefins with insertion of polar monomers in the chain, wherein the polar monomers are selected from the group consisting of vinyl alcohol, vinyl acetate, maleic anhydride, and combinations thereof. 
     
     
         4 . The process according to  claim 1  further comprising, following the spinning step, drawing the bicomponent fibre with drawing ratios varying within the range of 4-1. 
     
     
         5 . The process according to  claim 1 , wherein said step of applying an aqueous solution comprises immersing the cut fibres in a bath of an aqueous solution comprising inorganic salts. 
     
     
         6 . The process according to  claim 5 , further comprising, following the step of applying an aqueous solution, drying the cut fibres, wherein, after drying, the fibres have an inorganic salt content ranging between 0.5% and 2% of the initial weight. 
     
     
         7 . The process according to  claim 1 , wherein the backing layer on which the adhesive agent layer is applied is an orthogonal fabric, a knit fabric, a non-woven fabric, a non-woven elastomeric composite fabric, a film made of polyolefin, or paper. 
     
     
         8 . The process according to  claim 1 , wherein the adhesive agent that is placed on the backing layer is a polyurethane adhesive in an aqueous or solvent dispersion, a water-based acrylic adhesive, or a silicone glue. 
     
     
         9 . The process according to  claim 8 , wherein said adhesive layer further comprises a pigment capable of facilitating the subsequent flocking process, and/or additives capable of facilitating adhesion with the bicomponent fibre. 
     
     
         10 . The process according to  claim 1 , wherein said electrostatic deposition takes place in an environment with a controlled and constant level of humidity ranging between 60% and 90%, with the application of an electrostatic field ranging between 20 and 50 kV. 
     
     
         11 . The process according to  claim 10 , wherein the amount of cut fibres deposited on the backing layer ranges between 50 and 250 g/cm 2 . 
     
     
         12 . The process according to  claim 1 , wherein said removal agent comprises NaOH, or formic acid mixed with a polysaccharide. 
     
     
         13 . The process according to  claim 1 , wherein said removal agent is applied on the fibres in an amount ranging between 80 and 150 g/m 2 . 
     
     
         14 . The process according to  claim 1 , further comprising, following application of the removal agent, thermally treating the material with a saturated vapor current, radio frequencies, microwaves, or hot air. 
     
     
         15 . The process according to  claim 1 , wherein the viscosity of said sea component is greater than that of said removal agent. 
     
     
         16 . A flocked material comprising:
 a backing layer made of fabric or non-woven fabric;   an adhesive layer applied onto the surface of the backing layer or a portion thereof;   a fibrous layer comprising a plurality of sea-island fibres, having a sea component and an island component, that are partially immersed in the adhesive layer, wherein the sea component is present in the portion of fibres immersed within the adhesive layer and totally or partially absent in the section of fibres not immersed in the adhesive layer.   
     
     
         17 . The flocked material according to  claim 16 , wherein said adhesive layer is of a thickness ranging between 0.05 mm and 0.50 mm. 
     
     
         18 . The flocked material according to  claim 16 , wherein said plurality of sea-island fibres are immersed within the adhesive layer at a depth that ranges from 40 microns to the entire thickness of the adhesive layer. 
     
     
         19 . The flocked material according to  claim 16 , wherein the island component of the sea-island fibres has a titre in the range of 0.04 to 0.30 dtex. 
     
     
         20 . A method of using the flocked material according to  claim 16  in the field of automobiles, furnishings and consumer electronics, comprising the step of replacing some or all parts currently coated with fabrics, non-wovens or leathers with the flocked material of  claim 16 . 
     
     
         21 . A method of using the flocked material according to  claim 16 , comprising the step of coating surfaces and structures of the interiors of motor vehicles, objects for interior decorating, handbags, suitcases, covers or cases for weapons, musical instruments, or electronic devices with the flocked material of  claim 16 .