EP3573492B1

EP3573492B1 - Apparatus and method to obtain a permanent smooth effect on hair

Info

Publication number: EP3573492B1
Application number: EP18706859.8A
Authority: EP
Inventors: Luca PIETRUNTI
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-01-25
Filing date: 2018-01-25
Publication date: 2021-04-14
Anticipated expiration: 2038-01-25
Also published as: IT201700007876A1; EP3573492A1; WO2018138661A1; ES2880255T3

Description

Field of the invention

The present invention relates to a method for the treatment of hair, in particular for use by hairstylists, adapted to obtain hair with a permanent smooth effect without using aggressive chemicals.
The invention also relates to an apparatus intended to be used by hairstylists for obtaining hair with permanent smooth effect.

Background art

In the field of hairstyles, the practice is common of changing the natural look of the hair by providing a smooth look to naturally wavy, corrugated or curly hair.
Such a smooth look is conventionally obtained with physical-mechanical means and/or with chemical means.
Human hair come from hair follicles, in recesses of the epidermis which reach the dermis and end with a concave formation called bulb. The bulb encloses the skin papilla responsible for nourishing the hair. The corneous part which emerges from the hair follicle - the shaft - consists dead cells; instead the root remains vital for about three years, during which the shaft continues to lengthen because the cells continue being duplicated at the base thereof. The hair shaft consists of three layers: cuticle, cortex and medulla. The cuticle consists a plurality of layers of flat cells which partially overlap one another and protect the inner layers. Below the cuticle is the cortex, which mainly consists of keratin cells and pigments and which gives the hair its mechanical properties. Indeed, α-keratin is a fibrous protein the structural unit of which is represented by an α-helix which gives flexibility but simultaneously stability to the molecule in light of the hydrogen bonds present. α-Helices intertwine to form the protofibril, which is a filament held together by disulphide bonds. The protofibrils in turn are wound into fascicles which form the hair fibers. The smooth, wavy, corrugated or curly look of the hair depends on the shape of the cross section of hair, which in turn depends on that of the bulb cavity from which it originates; if the bulb is cylindrical in shape, the hair grows straight because the cell proliferation is uniform; if instead it is more or less flattened, the cell proliferation occurs in a non-uniform manner and it grows corrugated. The waviness given to the root is maintained in the shaft due to the presence of hydrogen bonds, saline bonds and disulphide bonds. To change the look of the hair, there is a need to break the aforesaid bonds, give the hair the desired shape and then promote reforming the bonds while the hair is kept in the desired shape. Conventionally, thermo-mechanical treatments and chemical treatments are used in order to change the look of the hair.
The thermo-mechanical treatments are applied by means of hot dry or steam hair plates, with which the hair is brought to temperatures usually between 130°C and 200 °C, and is kept in the desired shape. The conventional thermo-mechanical treatments are capable of reducing the saline bonds and the hydrogen bonds but have little effect on the disulphide bonds. For this reason, the effects which may be obtained with conventional thermo-mechanical treatments are very limited in time because as soon as the hair is exposed to humidity, the dissolution of the hydrogen and saline bonds occurs again, with loss of the effect. Chemicals capable of reducing the disulphide bonds are to be used to obtain increasingly long-lasting effects. However, the chemicals used for the aforesaid purposes almost always contain harmful components for the scalp, or at best, develop formaldehyde in the presence of heat, which is very harmful and therefore creates a risk for the health of the hairstylists and other operators in the field.
Patent document CN204561243 discloses an electric hair clamp that has cooling function, and where a hot splint can be connected in one end of the handle. Patent document EP1909609 discloses a hair styling appliance with two clamping members, at least one of which comprises a heating member for clamping hair to be styled. Patent document GB2459507 discloses another example of a hair styling device comprising a handheld portion incorporating a pair of tongs for contact-styling hair. Patent document JP2013063102 discloses a hair care device comprising a high temperature part and a low temperature part. Patent document JP2013085742 discloses another example of a hair styling device wherein two different temperatures are applied to hair during treatment Patent document WO 2015/190939 discloses cold hair tongs which can be used after having heated the hair with hot hair tongs.

Summary of the invention

It is the object of the present invention to suggest a method for the cosmetic treatment of hair, in particular for changing the movement look thereof by increasing or decreasing the corrugation by acting on hydrogen bonds, saline bonds, and in particular, on the disulphide bonds of the hair.
It is another object of the present invention to suggest a method for changing the corrugation of the hair without using chemicals for reducing the disulphide bonds of the hair.
It is a further specific object of the present invention to suggest a method for treating hair to obtain a permanent smooth look without using chemicals for reducing the disulphide bonds of the hair.
It is another object of the present invention to suggest an apparatus for the cosmetic treatment of hair, in particular for performing a thermo-mechanical treatment capable of giving the hair a permanent smooth look without the use of chemicals adapted to reduce the disulphide bonds of the hair.
It is a further object of the present invention to suggest an apparatus adapted to allow hairstylists to perform a thermo-mechanical treatment on clients' hair which gives it a permanent smooth look.
According to one aspect of the present invention, the aforesaid objects are achieved by a method for the cosmetic treatment of hair as defined in claim 13, and optionally, the method comprising the prior and preparatory steps of:

preparing the hair by cleansing and adding moisturizing and/or restructuring substances;
setting the hair with a desired corrugation grade, by keeping it in shape while simultaneously supplying heat.

A method as outlined above allows a hairstylist to perform a relatively simple treatment on a client's hair to obtain a permanent change of the look of the hair, without the need to resort to chemicals used to dissolve the disulphide bonds of the hair, which usually are harmful both for the client and the operators in the field. Further specific and characteristic aspects of the method outlined above are apparent in the related dependent claims.
According to another aspect of the present invention, the aforesaid objects are achieved by means of an apparatus for the cosmetic treatment of hair as defined in claim 1.

Brief description of the drawings

These and other features of the invention will become easier to understand by means of the following description of preferred embodiments thereof, provided by way of non-limiting examples, with reference to the accompanying drawings, in which:

figure 1 shows a diagrammatic depiction of cold hair tongs according to the present invention;
figure 2 shows a perspective view of the cold hair tongs of figure 1;
figure 3 shows a perspective view of an embodiment of an apparatus according to the present invention;
figure 4 shows a diagrammatic perspective view of the head of a person to which the steps of a method according to the invention, are applied;
figure 5 shows a block diagram of the steps of a preferred embodiment of the method according to the present invention, and
figure 6 shows a block diagram of the steps of a preferred embodiment of the method according to the present invention.

Detailed description of the invention

With reference to figure 1, a diagrammatic depiction of cold hair tongs 10 provided with cooling members 20, is indicated by numeral 100 as a whole.
As better shown in figure 2, the cold hair tongs 10 comprise a first jaw 11, and a second jaw 12, articulated to the first jaw. At least one of the first 11 and second 12 jaws is provided with a related cooled plate 13, 14, respectively. The cooled plates 13 and 14 are arranged facing each other so that the closing of the jaws 11 and 12 brings the cooled plates 13 and 14 in contact. The cooled plates preferably are made of high thermal conductivity metal material such as for example, steel, copper or copper alloys. Alternatively, said cooled plates may be made of crystal. In the embodiment in figures 1 and 2, the cooling members comprise a heat carrier liquid which circulates inside a circuit 21 of the heat carrier liquid, between an evaporator 22, a refrigerant circuit 30 and the cooled plates 13, 14. More specifically, the circuit 21 of the carrier liquid comprises a delivery piping 23 along which there is interposed a delivery pump 24, and which branches out in a delivery piping of the first jaw 23a, and a delivery piping of the second jaw 23b, which cross the first 11 and second 12 jaws, respectively, to bring the heat carrier liquid to the cooled plates 13, 14, which are in turn provided with carrier liquid circulation conduits (not shown). A return piping 25 branches out in the jaws 11, 12 into a return piping of the first jaw 25a, and a return piping of the second jaw 25b, which join again in a single conduit before connecting to an inlet opening of evaporator 22. The heat carrier liquid is a substance which is present in the liquid state at ambient pressure and at temperatures between -20 °C and 30°C. Advantageously, the heat carrier liquid is a mixture comprising demineralized water and a glycol selected from among ethylene glycol, diethylene glycol and propylene glycol.
The refrigerant circuit 30 comprises members of the refrigerant circuit consisting of a compressor 31, a condenser 32, a throttle valve 33, evaporator 22 and pipings 34, for the circulation of a coolant between the aforesaid members of the refrigerant circuit. Advantageously, evaporator 22 consists of a tank of heat carrier liquid inside of which is accommodated a portion of the pipings 34 of the coolant, arranged in a spiral. Tank 22 is insulated and is sealingly closed so that the heat carrier liquid itself in tank 22 and in the circuit 21 of the heat carrier liquid can be kept at a conditioned pressure, which is greater or less than the atmospheric pressure.
The cold hair tongs are also provided with electric control and supply members of the refrigerant circuit 30, which may comprise supply members from the electric network or batteries with related power transformation members. Moreover, there are at least one main power switch and at least one thermostat for regulating the temperature of the heat carrier liquid. Preferably, the aforesaid thermostat, therefore the temperature of the heat carrier liquid, can be regulated between -10 °C and 0°C.
With reference to figure 3, an embodiment, according to the invention, of an apparatus 100' for the cosmetic treatment of hair shown in a perspective view comprises a box-like casing 40' inside of which there is accommodated a refrigerant circuit substantially similar to that described with reference to figure 1, but not shown in figure 3, electrically operated cold hair tongs 10' and hot hair tongs 50', comprising a first jaw 51' associated with the hot hair tongs 50', a second jaw 52' associated with the hot hair tongs 50', and associated with at least one of the jaws 51' and 52', a heated plate 53', 54', preferably made of ceramic material, with the heated plates which are heated by means of electrically operated heating members, such as for example electrical resistors, which are not described in detail because of known art. In addition to containing the refrigerant circuit, the box-like body 40' comprises electrically operated members of the cold hair tongs 10' and of the hot hair tongs 50' and control members comprising at least one switch 41' of the cold hair tongs, a thermostat 42' of the cold hair tongs, a switch 43' of the hot hair tongs and a thermostat 44' of the hot hair tongs. Preferably, thermostat 44' of the hot hair tongs is suitable for regulating temperature T1 of the heated plates 53', 54' between 150°C and 300 °C. In a possible variant, the hot hair tongs 50' are provided with an interface for regulating the operating temperature. In another preferred embodiment of the present invention, there is an internal thermostat preset to keep the temperature of the heated plates 53', 54' at the desired temperature, for example about 230 °C.
The fact of using two distinct and separate tongs for heat treating and cold treating hair allows higher or lower temperatures to be obtained with respect to the case in which a single tong device alone provided both with hot plates and cold plates is used. Two plates integrated into a single tong device indeed interact with each other, affecting the respective temperatures which therefore, have limited temperature ranges and cannot be accurately controlled. Instead with the present invention, an operating temperature may be obtained of the hot hair tongs 50' at least equal to 230 °C, the temperature value required to dissolve the disulphide associations of the hair so as to make the smoothing practically permanent.
Moreover, in a preferred embodiment, the apparatus for the cosmetic treatment of hair according to the present invention advantageously may be provided with acoustic and/or optical warning means associated with a timer and adapted to warn that the application time interval of said cold hair tongs 10 and/or of said hot hair tongs 50' on a hair strand has elapsed.
According to another variant of the apparatus of the invention, the cooling members of the cold hair tongs 10, 10' do not provide for the presence of a heat carrier liquid and of the related circuit 21 of the heat carrier liquid, and the coolant gas of the refrigerant circuit 30 is caused to circulate directly in cooled plates 13, 14, which form the evaporator of the refrigerant circuit 30.
According to another variant of the apparatus of the invention, the fluid flowing in the cooling plate is cooled by means of at least one Peltier cell arranged in contact with a radiator provided with appropriate dissipators.
According to a further variant of the apparatus of the invention, the cooling members of the cold hair tongs 10, 10' consist of Peltier effect thermoelectric members. In this latter embodiment, the cooling members do not provide any refrigerant circuit or heat carrier liquid, whereby the structure of the cold hair tongs 10, 10' is much simpler, and in any case, the electric performance thereof is significantly lower.
A method for the cosmetic treatment of hair according to the present invention uses hot hair tongs and cold hair tongs, which may belong to an apparatus according to the present invention or may be other hair tongs of known technology.
With reference to figure 6, a method for the cosmetic treatment of hair, in particular for changing the corrugation grade of the hair in a substantially permanent manner, comprises the steps of the method defined in claim 13.
Moreover, with reference to figure 5, the method for the cosmetic treatment of hair according to the present invention may comprise the following prior and preparatory steps with respect to the application 230 of said thermal shock:

cleansing 210 the hair strand and adding moisturizing and/or restructuring substances;
preparatory thermo-mechanical treatment 220 of the hair strand adapted to achieve the desired corrugation grade by keeping it in shape while simultaneously providing heat until the hair is substantially dry.

The cleansing treatment 210 occurs by wetting the hair and applying a cleansing product, and also comprises the possible application of moisturizing and restructuring substances applied on the wet hair.
The preparatory thermo-mechanical treatment 220 is performed with hot hair tongs, such as for example hot hair tongs 50' of an apparatus 100' according to the present invention, and is performed according to the known techniques in the field for obtaining the desired final look, whether it is smooth, corrugated or curly.
In an advantageous embodiment of the method of the present invention, it is performed to obtain hair with a substantially permanent smooth look. In such an embodiment, the preparatory thermo-mechanical treatment 220 is performed with hot hair tongs with heated plates which are substantially flat and facing each other, causing the tongs to slide, strand by strand, for the whole length of the hair starting close to the insertion at the skin.
In the aforesaid embodiment, the step of applying 230 thermal shock is performed in sequence on portions of said hair strand following one another in the direction of the length, starting from a distance of at least 5 mm from the skin and substantially reaching the tip.
More specifically, with reference to figures 4 and 6, in a preferred embodiment of the method of the invention, the step of applying 230 a thermal shock comprises the steps described below:
applying 231 hot hair tongs 50' with heated plates at a temperature T1 between 150°C and 300 °C, preferably between 200 °C and 250 °C, on a first portion p1 of a strand C of hair, starting from about 5 mm from the skin. The length of the aforesaid first portion p1 is given by the width of the heated plates of the hot hair tongs 50'. The hot hair tongs 50' are kept posing 232 for a posing time interval t1 between 5 seconds and 30 seconds - preferably between 15 seconds and 20 seconds - and dependent on the temperature of the plate itself.
Once the posing time interval t1 has elapsed, the hot hair tongs 50' are rapidly transferred 233 to a second, immediately following portion p2 of hair. As soon as the transfer of the hot hair tongs 50' is complete, cold hair tongs 10' are immediately applied 234 at a temperature T2 below or equal to -2°C on the first portion p1 of the hair strand. The cooled plates of the cold hair tongs 10' advantageously are at a temperature T2 between -5°C and -10 °C and have a width equal to or less than the width of the heated plates of the hot hair tongs 50'.
The hot hair tongs 50' are kept posing 235 on the second portion p2 while the cold hair tongs 10' are kept posing 236 on the first portion p1 for the aforesaid posing time interval t1. At the end of the aforesaid posing time interval t1, the hot hair tongs 50' are rapidly and substantially simultaneously transferred 237 to a third portion p3 of the hair strand, which is a portion immediately following the second portion, the cold hair tongs 10' are transferred 238 to the second portion p2, which is a portion of the hair strand of immediately following the first portion.
The aforesaid steps of keeping posing 235, 236 and successive transfer 237, 238 to the successive portion are repeated until the completion of the treatment of the hair strand over the whole length thereof.
Obviously, the whole above-described step of applying 230 the thermal shock is repeated on each of the hair strands into which all the hair is divided so as to obtain a substantially permanent smooth and homogeneous effect on all the hair.
In essence, the above-described thermal shock treatment 230 allows the look of the hair obtained to be made permanent without requiring the use of any auxiliary chemical capable of dissolving the disulphide bonds. Indeed, the latter are effectively dissolved by the increased temperature of the hot hair tongs while the immediate successive use of the cold hair tongs makes the look obtained permanent.

Claims

An apparatus (100') for the cosmetic treatment of hair, comprising two distinct and separate hair tongs, said two distinct and separate hair tongs comprising:
hot hair tongs (50') comprising a first jaw (51') and a second jaw (52') articulated to the first jaw (51'), wherein at least one of said first jaw (51') and said second jaw (52') is provided with a heated plate (53', 54');

cold hair tongs (10,10') comprising a first jaw (11) and a second jaw (12) articulated to the first jaw (11), wherein at least one of said first jaw (11) and said second jaw (12) is provided with a cooled plate (13, 14);

cooling means associated with said cooled plate (13, 14);

heating means associated with said heated plate (53', 54');

control means associated with said cooling means and with said heating means, said control means comprising at least one thermostat for regulating the temperature of said cooled plate (13, 14) and of said heated plate (53', 54');

electric supply means associated with said control means.
An apparatus (100) according to claim 1, characterized in that both said first jaw (11) and said second jaw (12) of said cold hair tongs (10,10') are provided with a cooled plate (13, 14).
An apparatus (100) according to one or more claims from 1 to 2, characterized in that both said first jaw (51') and said second jaw (52') of said hot hair tongs (50') are provided with a heated plate (53', 54').
An apparatus (100) according to one or more claims from 1 to 3, characterized in that the cooling means associated with said cooled plate (13, 14) comprise Peltier effect thermoelectric devices.
An apparatus (100) according to one or more claims from 1 to 4, characterized in that said cooled plates (13, 14) are made of metal material selected in the group comprising steel, copper or copper alloys.
An apparatus (100) according to one or more claims from 1 to 4, characterized in that said cooled plates (13, 14) are made of crystal.
An apparatus (100) according to one or more claims from 1 to 6, characterized in that the cooling means associated with said cooled plate (13, 14) comprise a fluid circuit (21) adapted to circulate a heat carrier liquid between an evaporator (22) of a refrigerant circuit (30) and said cooled plates (13, 14).
An apparatus (100) according to claim 7, characterized in that said fluid circuit (21) comprises a delivery pump (24), a delivery piping (23) and a return piping (25), said delivery (23) and return (25) pipings being associated with the cooled plates (13, 14) of said second hair plate (10).
An apparatus (100) according to claim 8, characterized in that said delivery piping (23) comprises a delivery piping (23a) of the first jaw (11) of said cold hair tongs (10, 10') and a delivery piping (23b) of the second jaw (12) of said cold hair tongs (10,10'), which are thermally connected to the cooled plates (13, 14) of said cold hair tongs (10,10').
An apparatus (100) according to one or more claims from 8 to 9, characterized in that said return piping (25) comprises a return piping (25a) of the first jaw (11) of said cold hair tongs (10,10') and a return piping (25b) of the second jaw (12) of said cold hair tongs (10,10') which are thermally connected to the cooled plates (13, 14) of said cold hair tongs (10,10').
An apparatus (100) according to one or more claims from 1 to 10, characterized in that the heating means associated with said heated plate (53', 54') comprise electrically powered heating devices.
An apparatus (100) according to one or more claims from 1 to 11, characterized in that it comprises acoustic and/or optical warning means associated with a timer and adapted to warn that the application time interval of said hot hair tongs (50') and/or of said cold hair tongs (10,10') on a hair strand has elapsed.
A method for the cosmetic treatment of hair, in particular for changing the corrugation grade of the hair in a substantially permanent manner, comprising:
applying (230) a thermal shock to a hair strand while said hair strand is being kept in shape, said thermal shock comprising:
a) applying (231) hot hair tongs (50') provided with at least one heated plate (53', 54'), brought to a first temperature (T1), on a first portion (p1) of a strand (C) of hair close to the skin, for a posing time (t1);

b) the posing time interval (t1) having elapsed, applying (233) the hot hair tongs (50') to a second portion (p2) of the hair strand immediately following the first portion (p1);

c) applying (234) cold hair tongs (10'), brought to a second temperature (T2), on the first portion (p1) of the hair strand;

d) repeating steps b) and c) to successive portions of the strand (C) of hair;
wherein said first temperature (T1) is between 150° c and 300 °C, said second temperature (T2) is lower than or equal to -2°C, and said posing time (t1) is between 5 seconds and 30 seconds.
A method according to claim 13, characterized in that said first temperature (T1) is between 200 °C and 250 °C.
A method according to one or more claims from 13 to 14, characterized in that said second temperature (T2) is between -5 °C and -10 °C.
A method according to one or more claims from 13 to 15, characterized in that said posing time (t1) is between 15 seconds and 20 seconds.
A method according to any one of claims 13 to 16, characterized in that it comprises the preparatory steps before step a) of:
preparing the hair by cleansing and adding moisturizing and/or restructuring substances;

setting the hair, by keeping it in shape while supplying heat.