Coatings for conductive sanitary pads

Abstract

The present invention relates to a coating for conductive sanitary pads, to conductive sanitary pads comprising the coating, and to the use of the coating for conductive sanitary pads.

Description

[0001] TITLE : COATINGS FOR CONDUCTIVE SANITARY PADS

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The remote monitoring of conductive sanitary pads such as diapers , bandages and menstrual pads , to ensure that they are changed promptly, is a technology with great potential and ever-increasing interest . Said monitoring is typically based on sensors embedded in sanitary pads or added to the item to be monitored .

[0004] These products are widely used, especially in nursing facilities , in elderly and / or disabled population, with the purpose of :

[0005] - improving the conditions of the patient ; and

[0006] - optimising change of sanitary pads , with ensuing cost-effectiveness ( lower use of sanitary pads and enhanced ef ficiency in terms of work time for the healthcare staff ) .

[0007] Currently, the various sanitary pads available on the market include conductive sanitary pads comprising

[0008] - a breathable film (Plastik SpA technology, together with its production process ) ;

[0009] - conductive inks ; substantially consisting of parallel strips of the holder of the detection system .

[0010] A chip connected to a control unit which signals via wi-fi or Bluetooth the degree of absorption and / or the saturation level, is typically applied to the sanitary pad . The wet sanitary pad becomes conductive due to a change in the condition of the circuit , which therefore sends a signal to the chip and the latter sends it to the control unit .

[0011] The technology reported above reveals criticalities , essentially :

[0012] 1 . breathability of the film;

[0013] 2 . amount and application of inks . In particular, the sole application of conductive inks on the sanitary pads does not make the response of the circuit reliable given that either changes or overestimate of the response arise due to false signals or lack of signal . Advantageously, the present invention resolves the problems reported above, increasing the reliability of the responses of the circuits and with enhanced efficiency of the use of sanitary pads and the work time of the healthcare operators . As a matter of fact , the present invention provides for a coating which can be applied together with the breathable film and with the conductive inks , improving the performance of the sanitary pads comprising them .

[0014] Below is the detailed description of the present invention .

[0015] FIGURES

[0016] Figure 1 : The chart regarding the water vapour transmission rate (WVTR) of the breathable film with the coating of the present invention : The test was carried out with grammage equal to about 2 . 5 g / sqm so that the datum was within the mean of the industrial application range .

[0017] The breathable film with the coating of the present invention applied has a water vapour transmission rate that is markedly lower than the ones currently available on the market considering the same dry grammage .

[0018] Figure 2 : Table reporting the data of the test of Fig . 1 relating to water vapour transmission rate :

[0019] - STD : is the coating subject of the patent ;

[0020] - Test 1 : nitrocellulose resin at 50% with respect to the STD coating;

[0021] - Test 2 : nitrocellulose resin at 25% with respect to the STD coating;

[0022] - Test 3 : polyurethane resin considering the same dry content of the STD coating .

[0023] Figure 3 : Image of a sample-holder, characterised by 6 measurement cells , with a breathable film with conductive print for the WVTR breathability test . It should be observed that cells n° l and 2 relate to the area covered by the conductive inks and of the coating subject of the invention . Figure 4 : Table with the values measured on various samples as well as laboratory tests and field tests .

[0024] DETAILED DESCRIPTION OF THE INVENTION

[0025] In an embodiment , the present invention relates to a coating comprising :

[0026] - polymeric resin selected from the group consisting of : nitrocellulose, polyurethane, acrylic, vinylic, styrene acrylic and / or mixtures thereof ; preferably, said polymeric resin is selected from the group consisting of : nitrocellulose, polyurethane and / or mixtures thereof ;

[0027] - Solvent selected from the group consisting of : ethyl alcohol, ethyl acetate, tertiary alcohols (normal propyl, isopropyl ) , ethoxypropanol, methoxypropanol, isopropyl acetate and / or mixtures thereof ; preferably, said solvent is selected from the group consisting of : ethyl alcohol, ethyl acetate, and / or mixtures thereof ;

[0028] - additives selected from the group consisting of : waxes , plasticisers , keton resins , rosin resins , fumaric resins and / or mixtures thereof ; preferably, said additives are selected from the group consisting of : waxes , plasticisers , and / or mixtures thereof ; wherein :

[0029] - said polymeric resin is comprised in the range from 20- 55% by final weight of the mixture ; preferably, said polymeric resin is comprised in the range from 23-36% by final weight of the mixture ;

[0030] - said solvent is comprised in the range from 79%-44% by final weight of the mixture ;

[0031] - said additives are comprised in the range from 1% - 10% by final weight of the mixture ; and wherein the final sum of the elements reported above is equal to 100% . In an embodiment , the coating of the present invention is prepared by dispersing, by using industrial cowles , polymeric resins in mixture of ethyl acetate solvent and ethyl alcohol and others . Additives such as waxes and plasticisers and others are added once the dispersion has been obtained to improve the mechanical strength and the chemical-physical properties thereof .

[0032] The solid macro-components are dispersed in ethyl acetate or other solvents in industrial mixers at controlled temperature and time . The pre-mixing may be carried out both in a nitrogen-inerted and ambient atmosphere .

[0033] The pre-dispersed macro-components are subsequently mixed for a minimum period of one hour and a maximum period of two hours in the industrial mixer at a controlled temperature of 30 ° C ± 5 ° C to homogenise the product . The mixing may be carried out both in a nitrogen-inerted and ambient atmosphere .

[0034] In another embodiment , the present invention relates to the use of the coating of the present invention for conductive sanitary pads .

[0035] In another embodiment , the present invention relates to a conductive sanitary pad comprising the coating of the present invention .

[0036] Surprisingly, the Applicants found that the coating of the present invention is particular applicable to the conductive sanitary pads described in the present invention, comprising breathable films and conductive inks .

[0037] As a matter of fact , the existing overprint or protection or insulating coatings cannot be used for the protection of conductive inks on sanitary pads , given that they are not functional .

[0038] In the field of flexographic inks there are overprint coatings or primers or protection coatings , but all of them can be used for entirely different purposes . Advantageously, the coating of the present invention enables to protect the conductive ink in the best manner possible . Preferably, said conductive sanitary pad is selected from the group consisting of : incontinence pad, diaper, bandage, incontinence panty diaper (pants ) , panty diaper (pants ) , absorbent bed mat , menstrual pads .

[0039] Preferably, said sanitary pad comprises :

[0040] - the coating of the present invention;

[0041] - conductive ink;

[0042] - breathable film .

[0043] Preferably, said conductive ink comprises :

[0044] - polymeric resin selected from the group consisting of : nitrocellulose, polyurethane, acrylic, vinylic, styrene acrylic and / or mixtures thereof ;

[0045] - Conductive pigment selected from the group consisting of : carbon black, graphite and / or mixtures thereof ;

[0046] - Solvent selected from the group consisting of : ethyl alcohol, ethyl acetate, tertiary alcohols (normal propyl, isopropyl ) , ethoxypropanol, methoxypropanol, isopropyl acetate and / or mixtures thereof ;

[0047] - additives selected from the group consisting of : waxes , plasticisers , keton resins , rosin resins , fumaric resins and / or mixtures thereof wherein :

[0048] - said polymeric resin is comprised in the range from 15- 25% by final weight of the mixture ;

[0049] - said pigment is comprised between 8-15% by final weight of the mixture ;

[0050] - said solvent is comprised in the range from 59%-69% by final weight of the mixture ;

[0051] - said additives are comprised in the range from 1% - 10% by final weight of the mixture ; and wherein the final sum of the elements reported above is equal to 100% . Preferably, said breathable film consists of polyolefins filled with inorganic fillers ( calcium carbonate, talc, zeolite, silicon dioxide or oxides of various kind) .

[0052] Such breathable films may be laminated with a non-woven fabric of polyolefin origin (polypropylene, polyethylene, PLA, products of plant origin) .

[0053] The coating of the present invention is applied on the sanitary pad in dry form, using any technology known to the person skilled in the art for example rotogravure printing, flexography, lacquering or other spreading system .

[0054] Preferably, the amount of dry coating of the present invention spread on the sanitary pad is comprised in the range from 0 . 10 g / sqm - 5 . 0 g / sqm .

[0055] Advantageously, given its degree of dry residue, the coating of the present invention enables to adjust the breathability of the film . Such property of adjusting breathability in a controlled manner is a peculiar characteristic of the coating .

[0056] Advantageously, the coating of the present invention can be applied with the current flexographic printing technology and there is no need for changes to the current process for producing the material used for manufacturing diapers . The coating is applied in register under the conductive inks .

[0057] Advantageously, the coating reduces or eliminates the risk of a false signal of the system for detecting the electrical signal that would be obtained with the sole application of the conductive inks .

[0058] EXAMPLES

[0059] WVTR MEASUREMENT

[0060] The analytical technique used to evaluate the quality of the barrier offered by the protection coating of the present invention on a breathable film is the Water Vapour Transmission Rate (WVTR) . The purpose of use of the coating is to preserve the capacitive characteristic of the print with conductive inks , applied thereon, in the production of the breathable film for sanitary pads designed for adult incontinency . In particular, the use thereof is indispensable for preventing the excessive water vapour from passing through the breathable film, laminated or not laminated with non-woven fabric, which could create alterations and / or malfunctions in the printed circuit board .

[0061] Generally, the WVTR technique allows to measure the possibility of a plastic film to be permeated by the water vapour .

[0062] The values are determined with respect to a standard reference sample at a temperature T=37 . 8 ° C and %RH=60% according to the ASTM D6701 standard .

[0063] The recorded data are reported, as a unit of measurement , in g / (m2*24h) .

[0064] Typically, a breathable film has permeability values in a range comprised between 500 and 10 , 000 g / (m2*24h) .

[0065] In the event of a conductive sanitary pad there is considered a breathable film with low permeability (values between 500 and 3 , 000 g / (m2*24h) ) .

[0066] In this specific case, the application, through flexographic printing, of a protection coating on a breathable film determines , in terms of water vapour transmission rate, a percentage decrease in a range comprised between 50 and 80% . Fig . 2 shows the values measured on various samples as well as laboratory tests and field tests .

Claims

CLAIMS1) Coating comprising:- polymeric resin selected from the group consisting of: nitrocellulose, polyurethane, acrylic, vinylic, styrene acrylic and / or mixtures thereof;- Solvent selected from the group consisting of: ethyl alcohol, ethyl acetate, tertiary alcohols (normal propyl, isopropyl) , ethoxypropanol, methoxypropanol, isopropyl acetate and / or mixtures thereof;- additives selected from the group consisting of: waxes, plasticisers, keton resins, rosin resins, fumaric resins and / or mixtures thereof; wherein :- said polymeric resin is comprised in the range from 20- 55% by final weight of the mixture;- said solvent is comprised in the range from 79%-44% by final weight of the mixture;- said additives are comprised in the range from 1% - 10% by final weight of the mixture; and wherein the final sum of the elements reported above is equal to 100%.2) Coating according to claim 1, wherein:- said polymeric resin is selected from the group consisting of: nitrocellulose, polyurethane and / or mixtures thereof;- said solvent is selected from the group consisting of: ethyl alcohol, ethyl acetate, and / or mixtures thereof;- said additives are selected from the group consisting of: waxes, plasticisers, and / or mixtures thereof.3) Coating according to one or more of the preceding claims, wherein said polymeric resin is comprised in the range from 23-36% by final weight of the mixture.4 ) Use of the coating according to one or more of the preceding claims for conductive sanitary pads .5 ) Conductive sanitary pad comprising the coating according to one or more of claims 1-3 .6) Conductive sanitary pad according to claim 5 , wherein said conductive sanitary pad is selected from the group consisting of : incontinence pad, diaper, bandage, incontinence panty diaper, panty diaper, absorbent bed mat , pad .7 ) Conductive sanitary pad according to one or more of claims 5-6, wherein said conductive sanitary pad comprises :- coating according to one or more of claims 1-3 ;- conductive ink;- breathable film .8 ) Conductive sanitary pad according to claim 7 , wherein said conductive ink comprises :- polymeric resin selected from the group consisting of : nitrocellulose, polyurethane, acrylic, vinylic, styrene acrylic and / or mixtures thereof ;- conductive pigment selected from the group consisting of : carbon black, graphite and / or mixtures thereof ;- Solvent selected from the group consisting of : ethyl alcohol, ethyl acetate, tertiary alcohols (normal propyl, isopropyl ) , ethoxypropanol, methoxypropanol, isopropyl acetate and / or mixtures thereof ;- additives selected from the group consisting of : waxes , plasticisers , keton resins , rosin resins , fumaric resins and / or mixtures thereof . wherein :- said polymeric resin is comprised in the range from 15- 25% by final weight of the mixture ;- said pigment is comprised between 8-15% by final weight of the mixture;- said solvent is comprised in the range from 59%-69% by final weight; - said additives are comprised in the range from 1% - 10% and wherein the final sum of the elements reported above is equal to 100%.9) Conductive sanitary pad according to one or more of claims 5-8, wherein said breathable film consists of polyolefin filled with inorganic fillers.10) Conductive sanitary pad according to one or more of claims 5-9, wherein said coating according to one or more of claims 1-3 is dry and spread on said pad in the range comprised from 0.10 g / sqm- 5.0 g / sqm.

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