EP4139372A1

EP4139372A1 - A polymer

Info

Publication number: EP4139372A1
Application number: EP21718595.8A
Authority: EP
Inventors: David Graham; Volker Wendel; Christoph Tonhauser; Sandra Mack; Petra KEIE
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2020-04-23
Filing date: 2021-04-19
Publication date: 2023-03-01
Also published as: WO2021213954A1; BR112022021257A2

Abstract

The present invention relates to a polymer comprising repeating units derived from at least three different monomers, all of which are acrylic esters, methacrylic esters, acrylamides or methacrylamides, wherein this polymer has a calculated glass transition temperature of 29 to 44°C. Furthermore, the present invention relates to a composition suitable for use as a cosmetic formulation, wherein this composition comprises the said polymer, water and one or more further cosmetically acceptable ingredients. Furthermore, the present invention relates to the use of the said polymer or of the said composition for forming a film on human or animal hair or for styling human or animal hair.

Description

A polymer

The demand for longer lasting effects and improved efficacy or performance is present across a variety of industry segments, especially those involving the treatment or coating of surfaces. For example in agriculture, and in particular in crop protection there is a need to deposit and fix active ingredients at the surface of leaves or foliage even under challenging conditions such as wind and rain which would wash the aforementioned active off of the foliage before it has a chance to perform its task effectively. Analogous to foliage and wooden surfaces, metal surfaces which are exposed to mechanical stress and moisture also need to be treated to reduce potential wear and tear at the surface caused by mechanical stress e.g. rubbing, swelling and contraction due to temperature and or moisture. The home and personal care market also demands longer lasting effects which can be associated with surface coating, protection or modification. In home care for example stain prevention on textile fibers and enhanced water/liquid repellence, as well as anti-adhesive coatings to improve cleaning of hard surfaces such as floor tiles, dishes and cutlery. Within the personal care branch there are also areas which involve the direct application of compositions which contain film building components on or within the human body, for example in oral care, where anti-staining and anti-carries coatings for the teeth and in general oral health and appearance are significantly claimed areas of performance. The deposition and fixing of active substances that could be beneficial to oral health at the surface of the teeth to improve efficacy under the extreme conditions present in the mouth is also a significant area of interest within oral care. Similarly, there is a growing need to fix active ingredients at the surface of skin for a longer period to improve efficacy or simply to boost the duration of the desired effects. A specific example of where such effects may be beneficial within skincare is sun care/protection or more specifically UV protection for the skin or hair, where a UV filter or blocker is applied from a formulation, in this case a water-resistant film is needed to ensure that the active ingredient remains in place. l In the case of keratinous surfaces, and more specifically for hair the lack of agents which can deliver a water resistant coating to enable a longer lasting change of for example hair style, frizziness, or straightness mean that current methods for achieving such effects are harsh and potentially damaging to the hair, permanent modifications involve repeated straightening with a hot iron, or curling with a hot curling tool, coloring/bleaching as well as redox perm treatments, all of which rely on chemical hair modification and result in permanent damage to the keratinous fiber surface (cuticle). In the realm of hair styling, hair protection and most importantly hair repair, most of the commercially available products which claim longer lasting effects contain water soluble polymers and ingredients which can be removed simply by washing, negating the longer lasting claim. Common repair treatments also do not offer acceptable solutions in the long-term since the majority of the conditioning products are based on physical interactions with the keratinous fiber and can thus be washed out after usage.

Longer lasting effects such as forming of hair, reduction of frizz and volume, or generation of volume and style can currently only realistically be achieved by harsh chemical and heat treatments which involve breaking and sometimes forming new bonds within the hair, causing permanent damage to the hair fiber. Current options for using polymers to achieve longer lasting water or wash resistant effects are limited by the inherent solubility of classical cosmetic polymers while alternative hydrophobic polymers which find use in other applications do not fulfill the required performance parameters for cosmetic applications, for example providing stiffness but still being able to be formed into e.g. a hair style, as well as compatibility in water containing formulation types, indeed the wish for longer lasting water and wash resistant products in cosmetics is contradictory given that current trends move towards water containing formulations.

WO 2011/112768 describes formulations containing water insoluble film forming polymers with hydrogen bonding groups for deposition on the surface of plants and/or wood to enhance the rain fastness or water resistance at the surface of the said substrates in order to improve the topical efficacy of the active ingredients included in such formulations , one of the drawbacks in the described approach is the limitation to completely water free formulations which mean only oil or solvent soluble active materials and formulation components can be used.

US 2005/0054532 describes using water soluble hydrogen bonding polymers to form a complex with active ingredients in order to enhance solubility and delivery to the surface of leaves/plants, however this approach although improving controlled release of actives to the plant, does not reference a water-resistant film which will increase contact time with foliage under wet conditions. US 3/927/199 shows that terpolymers based on N-alkyl acrylamides or methacrylamides can be used in cosmetic applications, especially for hair cosmetic as good film-forming and setting agents

EP 1 694 728 B1 builds on the aforementioned work and describes the use of branched alkyl acrylate, especially those based upon tertiary butyl acrylate and/or methacrylate in combination with acrylamide or methacrylamide derivatives as long as a quaternisable or amiine functionalized acrylamide or methacrylamide monomer is also present. The copolymers discussed also contained an additional linear alkyl acrylate such as ethyl acrylate or methacrylate. Although the inventive polymers are said to hold improved setting and performance properties there are no teachings as to why this may be the case compared with US 3/927/199

EP 2 925799 B1 describes the synthesis and use of synthetic copolymers based on branched and linear acrylic esters combined with a cyclic N-Vinyl amide and further monomers which include non-quaternised acrylamides or methacrylamides. Such polymers appear to find use in applications as diverse as cosmetic hair and skin care, rheology modification in construction materials and emulsification in agricultural formulations. The importance of having a protonatable or quaternisable component to enhance interaction with with peptidic or proteic structures, however the discussion is limited to retaining solubility of the copolymers. The importance of glass transition temperature and its relevance for cosmetically acceptable performance are also discussed.

None of the aforementioned literature has demonstrated the potential for longer lasting and to a certain degree water resistant performance, such performance is normally achieved by using reactive agents which can undergo reaction with surfaces such as keratin leading to a permanent transformation, the following describe some examples of such materials or processes.

In the area of permanent hair styling WO 1999/007330 teaches that a “milder” non sensitizing method would be to employ keratin reducing agents such as N,N-disubstituted mercaptoacetamides, although these compounds are supposedly an improvement on harsher treatments in terms of sensitization and allergy potential, the mechanism still involves the reduction of bonds with in the hair fibre leading to inherent damage.

WO 2011/104282A2 describes semi-permanent straightening of frizzy, curly or wavy hair by treating the hair with glyoxylic acid in a buffer solution or formulation for 15 - 120 minutes, drying the hair before straightening with an iron between 150 - 250°C the results are hair chemically relaxed hair fibres which remain free of frizz for up to 5 washing cycles.

Alternatively, redox chemistry on hair utilizing the cystine/cysteine-residues of the keratinous fiber is well known for the perm treatment to create permanent waving. In the standard process at hair dressers the cystine gets reduced by ammonium thioglycolate and after shaping of the hair cysteine gets re-oxidized to cystine by hydrogen peroxide to reform the disulfide bonds in the hair structure. It is a harsh process which damages the hair structure.

Besides the perm treatment only few other examples are known using the cystine/cysteine- residues in keratinous fibers for permanent modification of the hair. Small organic molecules can be used to repair the hair structure by combining cysteine residues with each other (US 9,095,518 B2), use hydrophobic and cationic modified disulfides for conditioning of hair (WO 2013/050547) or use disulfide hair dyes to obtain a permanent hair color (EP 1 893694 B1).

EP 0 736 297 B1 describes a new material cysteine-silicon polymer for treatment of keratin substrates. The low molecular weight allows penetration into hair and removal of water lead to further polymerization/crosslinking of the silicon and thus to strengthening of the hair.

DE 102004024509 B4 describes the strengthening of hair structure using polycondensation product of cystine & succinyl chloride in a perm treatment.

The inventions mentioned previously are limited to only few single applications (e.g. hair dying and hair strengthening). In addition, in all cases a pretreatment of the keratin substrate with a reducing agent is mandatory for the described materials and processes.

The problem underlying the present invention is to provide a substance that can form a film on human or animal hair that has some resistance to being washed out with water, so that the human or animal hair can be modified, e. g. modified by hair-styling or by coloring, wherein this modification has some resistance to being washed out with water, without strongly damaging the hair as strongly as it occurs with known methods, e. g. heat treatment methods used to curl hair.

This problem is solved by the polymer according to claim 1 of the present patent application as filed. This polymer according to the present invention is one subject of the present invention. The following paragraphs describe the polymer according to the present invention, especially the monomers from which the repeating units are derived (by opening the polymerizable double bond of the monomer), in more detail.

Monomer A has formula (1) wherein Q is NH or O, R1 is H or CH₃, R2 is selected from the group consisting of H, CH₃, CH2CH3, CH2CH2CH3, CH2CH2CH2CH3, CH2CH2CH2CH2CH3, and a C6 to C22 linear or branched alkyl chain, R3 is H or CH₃, and R4 is H or CH₃.

Monomer B must be different from monomer A and has formula (2) wherein R5 is H or CH₃ and R6 is selected from the group consisting of H, CH₃, CH2CH₃, CH2CH2CH3, CH2CH2CH2CH3, CH2CH2CH2CH2CH3, and a C6 to C22 linear or branched alkyl chain.

Monomer C must be different from monomer A and different from monomer B and has either formula (3) or formula (4) wherein R7 is H or CH₃, R8 and R9 are independently selected from the group consisting of H, CH₃, and CH2CH₃, and n = 1-3. Monomer D must be different from monomer A and different from monomer B and different from monomer C and has formula (5) wherein R10 is H or CH3, R11 is selected from the group consisting of CH2CH2-N(CH3)2, CH₂CH2-N(CH₂CH3)2, CH₂CH₂CH2-N(CH3)2, and CH₂CH₂-N(H)C(CH₃)3, Y is O or N, and R12, only present in case Y is N, is H or CH3.

Monomer E must be different from monomers A to D and is any monomer having an ethylenically unsaturated, polymerizable C-C-double-bond. Preferably monomer E is selected from the group consisting of acrylic acid, methacrylic acid, 3,3,5-tri-methyl cyclohexyl methacrylate, styrene, vinyl neodecanoate, and vinyl neononaoate.

Repeating units derived from monomer A are present in the polymer according to the present invention in an amount of 30 - 65 % by weight, preferably in an amount of 40 - 55 % by weight, more preferably 45 - 55 % by weight.

Repeating units derived from monomer B are present in the polymer according to the present invention in an amount of 15 - 25 % by weight.

Repeating units derived from monomer C are present in the polymer according to the present invention in an amount of 0 - 15 % by weight. Repeating units derived from monomer C are optionally present. Preferably repeating units derived from monomer C are present in the polymer according to the present invention in an amount of 5 - 15 % by weight.

Repeating units derived from monomer D are present in the polymer according to the present invention in an amount of 10 - 30 % by weight, preferably in an amount of 15 - 30 % by weight, more preferably in an amount of 18 - 24 % by weight.

Repeating units derived from monomer E are present in the polymer according to the present invention in an amount of 0 - 5 % by weight, preferably in an amount of 0 - 3 % by weight, more preferably in an amount of 0 - 1.5 % by weight. Repeating units derived from monomer E are optionally present. The polymer according to the present invention must have a calculated glass transition temperature between 29 and 44 °C better still from 30-40 °C as calculated using the Fox equation (T. G. Fox, Bull. Am. Phys. Soc. 1 (1956) 123.):

Tg, mix = 1/(åi Wi/Tg,i) wherein Tg, mix = calculated glass transition temperature,

Wi = mass fraction of monomer,

Tg,i = glass transition temperature of homopolymer.

The following tables comprise a selection of glass transition temperatures Tg,i of some homopolymers. Further Tg,i-values can be found in literature resources known to the person skilled in the art, for example in the “Polymer Handbook” (editors: J. Brandrup et al, Wiley and Sons Ltd.).

Monomer A:

Monomer B:

Monomer C:

Alternative Monomer C:

Monomer D:

Monomer E:

The polymer according to the present invention offers mild electrostatic interaction with the hair surface as opposed to damaging chemical redox reactions with the hair structure. It provides a hydrophobic film after anchoring at the surface of the hair which prevents water or moisture from accessing the hair surface which is known to lead to frizz and loss of style, volume, or straightening. It enables the generation of reversible water-resistant films which can protect for example a hair style and/or ingredients applied at the surface of hair or skin,

The polymer according to the present invention can achieve permanent, semi-permanent or controlled reversible permanent effects when applied to hair or skin without using a chemical reaction e. g. redox mechanism to permanently damage or alter the structure of the surface. It can be formulated into water containing cosmetic formulations. The application of the polymer according to the present invention to hair or skin to reach the desired cosmetic effect can be done with a cosmetically acceptable formulation, such as a cream, a gel, a mousse, a serum, or a spray.

One of the advantages of the polymer according to the present invention compared to existing cosmetic polymers is the enabling of longer lasting effects via resistance to moisture, washing and mechanical stress. This is presumably due to the finding that a self-orienting polymeric film can provide water/moisture resistance as well as resistance to mechanical stress modification of the surface that stays over a long period of time to create a long-lasting perceivable benefit for end-users while not damaging the surface or substrate in the way that current long lasting modifications such as perms do.

The polymer according to the present invention can be made by conventional polymerization techniques known to the person skilled in the art.

The subject-matters of the claims dependent on claim 1 of the present patent application as filed are preferred embodiments of the polymer according to the present invention.

Another subject of the present invention is a composition suitable for use as a cosmetic formulation, wherein this composition comprises the polymer according to the present invention, water, and one or more further cosmetically acceptable ingredients different from the polymer and different from water

Suitable further cosmetically acceptable ingredients can be any cosmetically acceptable ingredient. These ingredients are known to the person skilled in the art and can be found in several publications, e. g. in the latest edition of the “International Cosmetic Ingredient Dictionary and Handbook” published by the Personal Care Products Council. Another well- known source of further suitable cosmetically acceptable ingredients is the cometic ingredient database Cosing. Cosing can be accessed on the internet pages of the European Commission.

Some of these further cosmetically acceptable ingredients, which are preferably used can be found in the following tables which represent examples of preferable cosmetic formulations according to the present invention. In these tables “AS” means “active substance”. P7 is the polymer according to the present invention.

Spray Type 1:

Spray Type 2 Spray Type 1

Mousse:

Mousse

Example Gel:

Example Cream 1 : Example Cream 2:

The formulations described in the previous tables can be made as follows.

Example Spray Type 1:

1) Prepare Phase A by adding the ingtredients (if necessary) to the water and allow to dissolve under stirring;

2) Combine the components of Phase B by adding the lactic acid to polymer p7 under stirring;

3) Add the ingredients listed as phase C under stirring to Phase B, and stir until dissolved; 4) Add Phase A to the previously prepared mixture under stirring until homogeneous.

Example Spray Type 2:

1) Prepare Phase A by combining the Ingredients and stir until homogeneous;

2) Add ingredients of Phase B and stir until homogeneous.

Example Mousse:

1) Combine the components of Phase A under stirring until homogeneous

2) Mix components of Phase B under stirring until homogeneous

3) Add Phase B slowly under stirring to Phase A until homogeneous

4) Fill into suitable mousse aerosol can and seal

5) Add Phase C directly to the sealed aerosol can

Example Gel or Cream 1 :

1) Mix the ingredients of Phase A under stirring

2) Mix the ingredients of Phase B under stirring

3) Mix ingredients of Phase D under stirring until a homogeneous gel is formed

4) Add Phase A, B and C together under stirring

5) Add Phase D to the mixture of Phases A, B and C under stirring until homogeneous Example Cream 2:

1) Mix the ingredients of Phase A under stirring until dissolved

2) Mix the ingredients of Phase C under stirring

3) Mix Phase B and D

4) Add Mixture of Phase B and D to Phase C slowly under stirring until homegeneous

5) Add Phase A to the mixture of Phase B, C and D slowly under stirring until homogeneous

The polymer according to the present invention can be comprised in a non-aerosol spray, typically at a concentration of 2.0 to 9.0 % by weight. This spray can further comprise a solvent, typically at a concentration of 50.0 to 88.0 % by weight. The solvent can be an alcohol e.g. ethanol; it can also be isopropanol or a volatile alkane such as n-pentane or mixtures thereof. This spray can further comprise an additional solvent which is water, typically at a concentration of 5.0 to 45 % by weight. This spray can further comprise a neutralizing agent, typically in an amount that results in a pH of the spray of pH = 4.5 to 7.5. The neutralizing agent can be a carboxylic acid e.g. lactic acid or other alpha hydroxy acids such as malic, citric, and tartaric acid. This spray can further comprise a humectant e.g. glycerol or propylene glycol typically at a concentration of 0.1 to 0.5 % by weight. This spray can optionally comprise a second polymer chosen from the polyquaterniums e.g. PQ-37, PQ-4 typically at a concentration of 0.25 to 0.5 % by weight, or neutral polylactams e.g. polyvinyl caprolactam or polyvinyl pyrrolidone typically at a concentration of 0.0 to 3 % by weight. This spray can optionally comprise a non-microbicidal additive e.g. triethyl citrate, typically in a concentration from 0.0 to 0.1 % by weight.

The polymer according to the present invention can be comprised in a non-aerosol mousse, typically at a concentration of 0.3 to 2.0 % by weight. This mousse can further comprise a solvent, typically at a concentration of 0.5 to 3 % by weight. The solvent can be an alcohol e.g. ethanol; it can also be isopropanol or a volatile alkane such as n-pentane or mixtures thereof. This mousse can further comprise an additional solvent which is water, typically at a concentration of 90 to 95 % by weight. This mousse can further comprise a neutralizing agent, typically in an amount that results in a pH of the mousse of pH = 5 to 7. The neutralizing agent can be a carboxylic acid e.g. lactic acid or other alpha hydroxy acids such as malic, citric, and tartaric acid. This mousse comprises an amphoteric surfactant e.g. cocamidopropyl betaine typically in a concentration of 1.5 to 15 % by weight. This mousse also comprises an emulsifier e.g. PEG-40 hydrogenated castor oil, ceteareth-25, or combinations thereof, typically in a concentration of 0.1 to 0.5% by weight. This mousse can optionally comprise a humectant e.g. glycerol or propylene glycol typically at a concentration of 0 to 5 % by weight. This mousse can optionally comprise a second polymer chosen from the polyquaterniums e.g. PQ-37 typically at a concentration of 0 to 0.5 % by weight. This mousse can further comprise a natural oil e.g. hydrogenated rapeseed oil, moringa olifeira seed oil typically in a concentration of 0 to 3% by weight. This mousse further comprises a preserving agent e.g. phenoxyethanol and ethylhexylglycerine typically at a concentration of 0.3 to 1.3 % by weight.

The polymer according to the present invention can be comprised in an aerosol mousse, typically at a concentration of 0.5 to 5.0 % by weight. This mousse can further comprise a solvent, typically at a concentration of 1.5 to 15 % by weight. The solvent can be an alcohol e.g. ethanol; it can also be isopropanol or a volatile alkane such as n-pentane or mixtures thereof. This mousse can further comprise an additional solvent which is water, typically at a concentration of 82 to 92 % by weight. This mousse can further comprise a neutralizing agent, typically in an amount that results in a pH of the mousse of pH = 4.0 to 7.0. The neutralizing agent can be a carboxylic acid e.g. lactic acid or other alpha hydroxy acids such as malic, citric, and tartaric acid. This mousse comprises at least one conditioning agent e.g. cetrimonium chloride typically in a concentration of 0.9 to 2.3 % by weight. This mousse can further comprise a humectant e.g. panthenol, glycerol or propylene glycol typically at a concentration of 0 to 5 % by weight. This mousse can optionally comprise a second polymer chosen from the polyquaterniums e.g. PQ-37 typically at a concentration of 0.0 to 0.35 % by weight or alternatively from the neutral polylactams e.g polyvinylcaprolactam, polyvinylpyrrolidone, typically at a concentration of 0.0 to 2.5 % by weight. This mousse further comprises a propellant which is a volatile gas e.g. propane or n-butane or isobutane or mixtures thereof typically at a concentration of 5 to 15 % by weight, alternatively a hydrofluorocarbon such as 1 ,1-difluoroethane or a volatile ether such as dimethylether also at concentrations of 5 to 15 % by weight. This mousse can also comprise a preserving agent e.g. dimethyloldimethylhydantoin, 1,3-bis(hydroxymethyl)-5,5-demithylimidazolidin-2,4-dion, typically at a concentration of 0.0 to 0.25 % by weight.

The polymer according to the present invention can be comprised in a gel-creme, typically at a concentration of 0.3 to 3 % by weight. This gel-creme can further comprise a solvent, typically at a concentration of 0.3 to 15 % by weight. The solvent can be an alcohol e.g. ethanol; it can also be isopropanol or mixtures thereof. This gel-creme can further comprise an additional solvent which is water, typically at a concentration of 83 to 99 % by weight. This gel-creme can further comprise a neutralizing agent, typically in an amount that results in a pH of the gel of pH = 4.5 to 7.5. The neutralizing agent can be a carboxylic acid e.g. lactic acid or other alpha hydroxy acids such as malic, citric, and tartaric acid. This gel-creme can further comprise a humectant e.g. panthenol, glycerol or propylene glycol typically at a concentration of 0.0 to 5.0 % by weight. This gel-creme can comprise a second polymer chosen from neutral or cationically charged rheology modifying polymers e.g. dimethylacrylamide/ethyltrimonium chloride methacrylate copolymer, PQ-37, or combinations thereof, typically at a concentration of 0.3 to 5.0 % by weight. This gel-creme further comprises an emollient or oil e.g. propyleneglycol dicarpylate/dicaprate typicall at a concentration of 0.2 to 10 % by weight. This gel-creme can further comprise a preserving agent e.g. benzyl alcohol and methylchloroisothiazolinon and methylisothiazolinone typically in a concentration of 0.0 to 1.5 % by weight.

The polymer according to the present invention can be comprised in a gel, typically at a concentration of 0.3 to 3 % by weight. This gel can further comprise a solvent, typically at a concentration of 0.3 to 15 % by weight. The solvent can be an alcohol e.g. ethanol; it can also be isopropanol or mixtures thereof. This gel can further comprise an additional solvent which is water, typically at a concentration of 60 to 95 % by weight. This gel can further comprise a neutralizing agent, typically in an amount that results in a pH of the gel of pH = 4.5 to 7.5. The neutralizing agent can be a carboxylic acid e.g. lactic acid or other alpha hydroxy acids such as malic, citric, and tartaric acid. This gel can further comprise a humectant e.g. panthenol, glycerol or propylene glycol typically at a concentration of 0.0 to 5.0 % by weight. This gel can comprise a second polymer chosen from neutral or cationically charged rheology modifying polymers e.g. PQ-37, dimethylacrylamide/ethyltrimonium chloride methacrylate copolymer, typically at a concentration of 0.3 to 5.0 % by weight. This gel further comprises a solubilizing agent e.g. PEG-40 Hydrogenated castor oil, typically in a concentration of 0.2 to 0.5 % by weight. This gel can further comprise a preserving agent e.g. phenoxyethanol and ethylhexylglycerine typically in a concentration of 0.1 to 0.5 % by weight.

Examples

Abbreviations

Polymer Synthesis

The synthesis of the polymer P7 was carried out as follows, the other polymers were synthesized accordingly: A solution in ethanol (462.5 kg) and water (284.62 kg) of monomer C (185 kg) was pre-charged into a suitable reaction vessel. The pre-charged reaction vessel was then purged three times with nitrogen and warmed to between 60 °C and 80 °C. The initiator 2,2’-azobis-(2-methylbutyronitrile) (5.89 kg) was dissolved in ethanol (111.91 kg) and delivered into a feed vessel (first initiator feed) which had been purged three times with nitrogen. Once the reaction vessel had reached the desired reaction temperature of 70 °C a shot making up 15.1 wt% of the first initiator feed was fed into the reaction vessel to initiate polymerization. After 10 minutes the remainder of the first initiator feed was fed into the reaction vessel at a constant rate over 6 hours until the feed was used up. The temperature was held constant during this process. Simultaneously, the addition of a monomer feed composed of monomer A (925 kg), monomer B (370 kg), monomer D (370 kg) and ethanol (185 kg) was started and continued at a constant rate until the feed was used up after three hours. The reaction-mixture was stirred for further 2 to 3 hours while maintaining the constant reaction temperature. The Post polymerization process was carried out as follows, the reactor was heated to 10 degrees above the reaction temperature, and a feed containing initiator (9.25 kg) and ethanol (175.75 kg) was fed into the reactor over 30 minutes. After 2 hours of stirring a further amount of initiator (9.25 kg) in ethanol (175.75 kg) was introduced to the reactor over 30 minutes. The reaction-mixture was then stirred at 10 ^°C above the reaction temperature for a further 8 hours. After this 8 hours post-polymerization-procedure the reaction mixture was cooled and diluted with ethanol (1850 kg) before filling into suitable containers. No further work-up was necessary.

Polymers Made (Table 3: Monomer Combinations)

comparitive example; others: example according to the present invention

The polymers made were tested for curl retention, bending stiffness and wash resistance. The test methods are described after the following table with the test results. Wash resistance is rated from 1 to 4 (1 = excellent wash resistance, 4 = no wash resistance) and converted to a %-value using the following equation

% Wash resistance = 100 - ((rating/4) * 100) Test Results (Table 4: Experimental Results)

*comparitive example; others: example according to the present invention 'measured at VOC 90 due to formulation limitations at VOC 50

**Hydrophobic component means the amount of hydrophobic monomers used. A solubility of less than 1.5 wt % in water at 20 °C is defined as hydrophobic).

Unexpectedly given their hydrophobic nature many polymers display solubility in solutions containing up to 47 % water (with the exception of P2 and P4 which only tolerate 7 % water in the formulation), furthermore some polymers such as P6, P7, P10, P11 , and P15 display wash resistance or wash fastness as demonstrated in wash resistance screening tests while still being clearly soluble in solutions containing up to 47 % water (1 = excellent, 4 = no wash resistance). More surprising is that the aforementioned polymers display better wash resistance than more hydrophobic polymers such as P1-5.

(VOC 50 solutions were composed of 3 % polymer, 50 % EtOH and 47 % H20. VOC 90 solutions, in the case of P2 and P4, were composed of 3 % polymer, 90 % EtOH and 7 % H20.)

A polymer is according to the present invention if the following criteria are met:

• Wash resistance: 50 % or higher and

• Bending stiffness: 95 % or higher and

• Curl Retention 70 % or higher (as this is commonly accepted as a lower limit for cosmetic “hold” in hair styling applications)

Fig. 1 shows a series of polymers and comparative polymers organized with decending hydrophobic monomer content (here a solubility of less than 1.5 wt % in water at 20 °C is defined as hydrophobic).

On the left of the chart the polymers with the highest hydrophobic content display low wash/water resistance contrary to normal expectations whereas certain polymers with a much lower degree of hydrophobic monomers display a significantly better wash/water resistance. It is well known that a lower TG generally leads to a more flexible polymer whereas a higher TG leads to hard and sometimes brittle materials, this tendency is aptly demonstrated by the series P2*, P3* and P4* as well as P2*, P5*, P6 and P15 in terms of bending stiffness. P8* and P9* do not fit to the commonly expected trend when observing TG with respect to P7. This also suggests that calculated TG alone cannot be taken as an indicator for the performance parameters of curl retention (CR), wash resistance (WR) and bending stiffness (BS). We can observe that the inventive polymers P6, P7, P10, P11 and P15 fall into a selected area of the graphic. They possess a hydrophobic monomer content (HP) of 60-80 % and a glass transition temperature (TG) between 30 and 40 °C. Other polymers which display a good WR of 50 % where hydrophobic content lies above 80 % and TG lies outwith the 30-40 °C range display reduced performance in terms of the other necessary parameter BS. Many of them also have a poor CR value.

Fig. 2 further shows the effect of remaining in the above described areas (HP 60-80 %, TG 30- 40 °C) as polymers which lie outwith these areas e.g. comparison P6, P15, P16* and P17* at constant HP but reduced TG demonstrate rapid loss in cosmetic performance (BS, CR) whereas the best performance is observed at the outer limits of these ranges for P11 which displays the best water resistance despite having the lowest content of hydrophobic monomers.

Test Methods

Bending Stiffness Test

Caucasian, dark brown hair strands of 2 g weight and 15 cm length shaped into a rounded form with lace and with a gluing length of 1 cm were used for the test. These hairs were medium bleached with 5 % hydrogen peroxide in advance of the testing procedure. 7 such hair strands are used per product to be tested.

For the purposes of testing pump-spray type formulations, solutions of the polymer with a 3 % polymer content were prepared with a neutralization of 30 wt-% of available amine functionality using lactic acid dilution with ethanol or water was necessary to reach the desired VOC content of the test solution.

Each hair strand was dipped into the polymer solution, upon removal from the solution each hair strand was re-formed into the rounded shape and any excess hairs were gathered together by running the strand between the fingers without exerting pressure. This process was repeated once more. The strands were then dipped once again, the excess was then removed by pulling the hair strand (top to bottom) through a specially designed Teflon form, the hair strand was pulled through the Teflon form three times without any further dipping steps. The formed hair strands were then hung vertically in a rack, where the hair strands were left to dry for at least 1 hour under normal laboratory conditions. After drying the rack and strands were placed in a climate chamber at 65 % relative humidity and 21 °C overnight.

The maximum force needed to break the hair strands was then measured in cN using a device such as a texture analyser with a 3 point bending stiffness test set-up described in the following photo or any one of a number of similar devices which can measure force required until breaking point e.g. a Diastron . The process was repeated for the remaining hair strands in order to obtain a mean value of maximum force before breakage. This value is then converted to a percentage by the following equation

%BS = (BS/1000) x 100

Fig. 3 shows an example of a 3 point bending stiffness test on a texture analyser where the treated hair strand is bent to breaking point by the probe which is connected to force measurement cell.

Curl Retention

Dark brown hair strands of 2 g free hair, 15 cm length were held together with a round shaped lace of 1 cm length. The hair strands were bleached with 5 % hydrogen peroxide before use. Each polymer was formulated in a solution of ethanol and water with a VOC content of 5 % (unless stated otherwise) the polymer amine content was always neutralized to 30 % using lactic acid (comparative polymer examples without amin functionality do not need to be neutralized in this way). The hair strands were dipped into de-ionised water for fifteen minutes, excess water was subsequently squeezed out of the strands between two fingers.

The wet hair strands were wound onto Teflon curlers with guides to ensure consistent curling over all strands. The curlers with hair strands were then dried at 7 ^O0C for at least 3 hours and are subsequently cooled overnight. Each hair strand was unwound and attached to a lab stirrer, approximately 3 g of polymer solution was sprayed from a distance of 20 cm from a pump spray device while the hair strand was rotated at 70 rpm. Per polymer sample 5 such strands were prepared. The strands were then allowed to dry for 1 hr under ambient conditions on filter paper before being hung on a rack with a scale into a climate chamber at 25 °C and 90 % rh the initial length of the strand and the length after 5 h and 24 h was recorded accordingly.

The curl retention (CR) was then calculated using the following formula CR in % = [(L-Lt)/(L-Lo)] x 100

Where: L = Length of hair (15cm)

Lo = Length of hair curl, start

L_t = Length of hair curl, after a certain period of time (5h/24h)

Subjective Wash Resistance Test

A 3 % polymer solution neutralized to 30 % (if containing amine functionality) was prepared to VOC50 (unless otherwise stated). 3 ml of said solution were applied to a clean glass plate and distributed evenly with the end of a pipette, the resulting polymer film was left to dry for 2 h under ambient conditions (minimum 25 °C). After drying, three individual droplets of de-ionized water were applied from a pipette to three different locations upon the surface of the dried polymer film, after 15 seconds the droplets were wiped from the surface of the polymer film using a gloved finger and the water resistance of the film rated as follows.

4 = film under droplet completely removed with sharp edges and glass exposed 3 = film under droplet not completely removed, visible particulates/greyish rest on glass 2 = film still present on glass but some opacity present 1 = no visible change to polymer film

The results are then converted to a percentage wash resistance using the following equation:

% Wash resistance = 100-((rating/4)*100)

Claims

1 . A polymer comprising repeating units derived from monomer A having formula (1) wherein Q is NH or O,

R1 is H or CH₃,

R2 is selected from the group consisting of H, CH₃, CH2CH₃, CH2CH2CH₃, CH2CH2CH2CH₃, CH2CH2CH2CH2CH₃, and a C6 to C22 linear or branched alkyl chain,

R3 is H or CH3, and R4 is H or CHs, monomer B, being different from monomer A, and having formula (2) wherein R5 is H or CH₃ and

R6 is selected from the group consisting of H, CH₃, CH2CH₃, CH2CH2CH₃, CH2CH2CH2CH₃, CH2CH2CH2CH2CH₃, and a C6 to C22 linear or branched alkyl chain, monomer C, being different from monomer A and different from monomer B, and having either formula (3) or formula (4) wherein R7 is H or CH₃,

R8 and R9 are independently selected from the group consisting of H, CH₃, and CH2CH3, and n = 1-3, monomer D, being different from monomer A and different from monomer B and different from monomer C, and having formula (5) wherein R10 is H or CH₃,

R11 is selected from the group consisting of CH2CH2-N(CH3)2, ChhChh-I KChhCHsK CH₂CH₂CH2-N(CH3)2, and CH₂CH₂-N(H)C(CH₃)3,

Y is O or N, and

R12, only present in case Y is N, is H or CH₃, and monomer E, which is different from monomers A to D, and which is any monomer having an ethylenically unsaturated, polymerizable C-C-double-bond, and which preferably is selected from the group consisting of acrylic acid, methacrylic acid, 3,3,5-tri-methyl cyclohexyl methacrylate, styrene, vinyl neodecanoate, and vinyl neononaoate, wherein the repeating units derived from monomer A are present in the polymer in an amount of 30 - 65 % by weight, preferably in an amount of 40 to 65 % by weight, more preferably in an amount of 45 - 55 % by weight, and wherein the repeating units derived from monomer B are present in the polymer in an amount of 15 - 25 % by weight, and wherein the repeating units derived from monomer C are present in the polymer in an amount of 0 - 15 % by weight, preferably 5 - 15 % by weight, and wherein the repeating units derived from monomer D are present in the polymer in an amount of 10 - 30 % by weight, preferably in an amount of 15 - 30 % by weight, more preferably in an amount of 18 - 24 % by weight, and wherein the repeating units derived from monomer E are present in the polymer in an amount of 0 - 5 % by weight, preferably in an amount of 0 - 3 % by weight, more preferably in an amount of 0 - 1.5 % by weight, and wherein the polymer has a calculated glass transition temperature Tg,mix of 29 to 44°C, preferably 30 - 40°C, as calculated using the equation

Tg.mix = 1/(åi w Tg.i), wherein w, is the mass fraction of the repeating units derived from monomers A to E in the polymer, and

Tg,i is the glass transition temperature of the homopolymer of monomers A to E.

2. The polymer according to claim 1 , wherein monomer A has formula (1) wherein Q is O,

R1 is H or CH₃,

R2 is selected from the group consisting of CH₃, and CH₂CH₃ R3 is CH₃, and R4 is H or CHs.

3. The polymer according to claim 1 or 2, wherein monomer B, being different from monomer A, has formula (2) wherein R5 is H or CH₃ and

R6 is selected from the group consisting of H, CH₃, CH2CH₃, CH2CH2CH₃, CH2CH2CH2CH3 and CH2CH2CH2CH2CH3.

4. The polymer according to any of claims 1 to 3, wherein monomer C, being different from monomer A and different from monomer B, has formula (4) wherein n = 1-3.

5. The polymer according to any of claims 1 to 4, wherein monomer D, being different from monomer A and different from monomer B and different from monomer C, has formula (5) wherein R10 is H or CH₃,

Y is N, and R12 is H or CHs.

6. The polymer according to any of claims 1 to 5, wherein the repeating units derived from the monomers are present in the following amounts:

A: 40 to 65 % by weight, preferably 45 - 55 % by weight,

B: 15 to 25 % by weight,

C: 5 to 15 % by weight,

D: 10 to 30 % by weight, preferably 18 to 24 % by weight,

E: 0 to 1.5 % by weight.

7. The polymer according to any of claims 1 to 6, wherein the calculated glass transition temperature is 30 to 40 °C.

8. The polymer according to claim 1 , wherein monomer A is tertiary-butyl acrylate, monomer B is n-butyl acrylate, monomer C is vinyl pyrrolidone or vinyl caprolactam, monomer D is dimethylaminopropylmethacrylamide, and wherein the repeating units derived from the monomers are present in the following amounts:

A: 40 to 65 % by weight, preferably 45 - 55 % by weight,

B: 15 to 25 % by weight,

C: 5 to 15 % by weight,

D: 10 to 30 % by weight, preferably 18 to 24 % by weight,

E: 0 % by weight, and wherein the calculated glass transition temperature is 30 to 40 °C.

9. A composition suitable for use as a cosmetic formulation, wherein this composition comprises the polymer according to any of claims 1 to 8, water, and one or more further cosmetically acceptable ingredients different from the polymer and different from water.

10. The composition according to claim 9 comprising

0.2 to 5 % by weight, preferably 0.5 to 3 % by weight, of the polymer,

5.0 to 90.0 % by weight, preferably 6.0 to 80 % by weight, of water, and

5.0 to 90.0 % by weight, preferably 6.0 to 87 % by weight, of the one or more further cosmetically acceptable ingredients.

11 . The composition according to claim 9 or 10, wherein the one or more further cosmetically acceptable ingredients, named according to INCI-nomenclature, are selected from the group consisting of alcohol, lactic acid, parfum, panthenol, ethylhexyl methoxycinnamate, triethyl citrate, polyquaternium-37, polyvinylcaprolactam, cetrimonium chloride, DMDM hydantoin, propan, butan, polyquaternium-33, PEG-40 hydrogenated castor oil, phenoxyethanol, ethylhexyl-glycerine, dimethylarcylamide/ethyltrimonium chloride methacrylate copolymer, poropylenglycol dicaprylate/dicaprate, PPG-1 trideceth-6 and C10-C11 isoparaffin.

12. The use of the polymer according to any of claims 1 to 8 or of the composition according to any of claims 9 to 11 for forming a film on human or animal hair.

13. The use of the polymer according to any of claims 1 to 8 or of the composition according to any of claims 9 to 11 for styling human or animal hair.

14. A process for treating human or animal hair, preferably for forming a film on the hair or for styling the hair, comprising contacting the hair with the polymer according to any of claims 1 to 8 or with the composition according to any of claims 9 to 11.