WO2020020717A1

WO2020020717A1 - A multi-block copolymer, preparation process and composition thereof

Info

Publication number: WO2020020717A1
Application number: PCT/EP2019/069214
Authority: WO
Inventors: Zhen Yuan QU; Jing Luo; Ke Wang; Cristina Cepraga; Wenjun Zhu; Anchao FENG; San Hoa Thang
Original assignee: Basf Se
Priority date: 2018-07-25
Filing date: 2019-07-17
Publication date: 2020-01-30

Abstract

The present invention relates to a novel multi-block copolymer comprising more than three blocks, including at least a block A and a block B, wherein the block A is a cationic block and the block B is a nonionic block. The invention more specifically relates to a rinse-off personal care composition comprising the multi-block copolymer. The invention also relates to a process for the preparation of the multi-block copolymer. The invention still relates to a method for obtaining improved conditioning performance and enhanced deposition of benefit agents onto a surface by utilizing the multi-block copolymer.

Description

A Multi-block Copolymer, Preparation Process and Composition Thereof

Technical field

The present invention relates to a novel multi-block copolymer comprising more than three blocks, including at least a block A and a block B, wherein the block A is a cationic block and the block B is a nonionic block. The invention more specifically relates to a rinse-off personal care composition comprising the multi-block copolymer. The invention also relates to a process for preparation of the multi-block copolymer.

Background Art

Depositing a polymer and benefit agents onto a surface is useful for various purposes. For ex- ample, many compositions to be applied on hair, including hair-care compositions, such as shampoos, conditioners, volumizers, compositions combining several effects usually called“two in one”, comprise a polymer and benefit agents to be deposited onto the skin and/or hair sur- face. In cosmetic compositions, depositing a polymer and benefit agents is important to have some beneficial effects to skin and/or hair such as having improved sensory feel, enhanced deposition of caring active ingredients, modifying the mechanical properties of the hair, modify- ing its aspect, preventing entangling, easing combing and disentangling, etc. For this purpose, cationic polymers are widely used on the market, for example, cationic guars (e.g. Jaguar C13S, sold by the company Solvay), cationic hydroxylethyl cellulose (PQ-10, e.g. JR400, sold by the company Dow Chemical), and some other synthetic polymers, like diallyldimethylammo- nium chloride (DADMAC)-acrylamide copolymer (Salcare Super 7, sold by the company BASF), (3-acrylamidopropyl) trimethyl-ammonium chloride (APTAC)-acrylamide copolymer (e.g. Salcare SC60, sold by the company BASF; Merquat 550, sold by the company Lubrizol).

Obtaining good deposition of a conditioning agent is complicated by the action of anionic deter- sive surfactants in the personal care composition. Anionic detersive surfactants are designed to carry away or remove oil, grease, dirt, and participate matter from the hair and skin. In doing so, the anionic detersive surfactants can also interfere with deposition of the conditioning agent, and both deposited and non-deposited conditioning agents can be removed during rinsing. This further reduces deposition of the conditioning agents onto the hair or skin after rinsing, thus fur- ther reduces conditioning performance.

Some attempts have been made to obtain a polymer which is more suitable for use in personal care composition and can lead to good stability and/or deposition effect. U.S. Patent publication No. 2003/0216501 discloses an aqueous formulation comprising a water-soluble block copoly- mer comprising at least one charged block, combined with at least one or more ionic compound having one or more charges, opposite to the charge of the block. The aqueous formulation was found not to precipitate nor undergo phase-separation. U.S. Patent Publication No.

2004/0010074 discloses a method for depositing a polymer onto a surface, by applying an aqueous composition. The aqueous composition comprises a block polymer comprising at least two blocks A and B, wherein block A is a polyionic block and block B is a neutral block. The composition could improve the deposition or the effect of benefit compounds. However, a satis- factory conditioning performance is still not achieved.

However, most personal care formulations that contain both an anionic surfactant and a cationic deposition polymer have either a relatively low level of coacervate and unsatisfactory condition- ing performance or require a high molecular weight to achieve good conditioning effect via de- sirable levels of coacervate formation. However, such high molecular weight causes problems, such as high viscosity during polymerization, difficulty in eliminating residual mono- mer/chemicals, low solid content of polymer solution and high transportation cost, slow dissolu- tion during making a formulation and limited compatibility with other ingredients etc.

It thus remains a challenge to obtain a polymer, with a lower level of molecular weight, which can provide improved conditioning performance via coacervate formation, and sufficient deposi- tion of the conditioning/benefit agents onto hair/skin surfaces.

Summary of Invention

In one aspect, the present invention is directed to a multi-block copolymer comprising more than three blocks, including at least a block A and a block B; wherein the block A is a cationic block, and the block B is a nonionic block. Preferably, the nonionic block B is composed of water- soluble/hydrophile nonionic monomers

Preferably, the cationic block A has a degree of polymerization of from 5 to 500. Preferably, the cationic block A has a degree of polymerization of from 10 to 400. Preferably, the cationic block A has a degree of polymerization of from 20 to 300. More preferably, the cationic block A has a degree of polymerization of from 30 to 150.

Preferably, the multi-block copolymer has a charge density between 0.5 and 8 meq/g. More preferably, the multi-block copolymer has a charge density between 1 and 4 meq/g. Even more preferably, the multi-block copolymer has a charge density between 1.5 and 3.5 meq/g.

In some embodiments, the multi-block copolymer comprises at least five blocks. The multi-block copolymer can be a linear copolymer. In one embodiment, the multi-block copolymer is a penta- block copolymer which constitutes a molecular structure of (block A)-(block B)-(block A)-(block B)-(block A); in another embodiment, the multi-block copolymer is a hexa-block copolymer which constitutes a molecular structure of (block A)-(block B)-(block A)-(block B)-(block A)- (block B). In still another embodiment, the multi-block copolymer is a hept-block copolymer which constitutes a molecular structure of (block A)-(block B)-(block A)-(block B)-(block A)- (block B)-(block A).

The multi-block copolymer can be a branched copolymer which means the copolymer having one or more branch points (“arms”), or constitute more than one linear multiblock copolymers that are crosslinked together, typical polymer architecture includes star, dendritic, comb, and hyperbranched polymers. In some embodiments, the branched copolymer of the present inven- tion may comprise at least two arms, preferably from 3 to 8 arms, more preferably from 4 to 6 arms.

Preferably, at least one end of the multi-block copolymer is the cationic block. More preferably, each end of the multi-block copolymer is the cationic block.

In another aspect, the present invention further relates to a process for the preparation of the multi-block copolymer. The process can be living polymerization or controlled free-radical polymerization processes including anionic addition polymerization, reversible addition- fragmentation chain transfer (RAFT)/macro molecular design via interchange of xanthates (MADIX), nitroxide-mediated radical polymerization (NMP) and atom transfer radical polymeriza- tion (ATRP). The multiblock copolymer can also be made by connecting multiple homopolymers together at the terminals.

In a further aspect, the present invention relates to use of the multi-block copolymer in forming a personal care composition. In particular, the personal care composition is rinse-off personal care composition to be used on skin or hair. In more particular, the personal care composition is a shampoo or hair-conditioning formulation.

In still another aspect, the present invention relates to a composition comprising the multi-block copolymer and at least one surfactant. Preferably, the surfactant is anionic surfactant. More preferably the surfactant can be a sulfate-based anionic surfactant, a sulfonate-based anionic surfactant, a carboxylate-based anionic surfactant or a combination thereof.

Surprisingly and unexpectedly, it has been found that the multi-block copolymer, having a lower level of molecular weight, can lead to more efficient deposition of benefit agents and excellent conditioning performance such as reduction of wet combing force, when being used in forming a personal care composition.

Other characteristics, details and advantages of the invention will emerge even more fully upon reading the description which follows.

Detailed description

While the specification concludes with claims that particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following de- scription.

Throughout the description, including the claims, the term "comprising one" or“comprising a" should be understood as being synonymous with the term "comprising at least one", unless oth- erwise specified, and "between" should be understood as being inclusive of the limits. The articles“a”,“an” and“the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.

The term“and/or” includes the meanings“and”,“or” and also all the other possible combinations of the elements connected to this term.

All percentages, parts and ratios are based upon the total weight of the composition of the pre- sent invention, unless otherwise specified. All such weights are they pertain to listed ingredients are based on the active level and, therefore do not include solvents or by-products that may be included in commercially available materials, unless otherwise specified.

The term "multi-block copolymer" as used herein refers to a polymer comprising two or more chemically distinct regions or segments (referred to as“blocks”). The“blocks” may differ in the amount or type of incorporated comonomer, density, amount of crystallinity, type or degree of tacticity, regio-regularity or regio-irregularity etc. For example, an A-B block copolymer includes a block A formed from monomers of the same or similar type; and a block B formed from mon- omers of the same or similar type. The blocks A and B may have the same or different block length, that is, the number of repeat units in the two blocks may be the same or different. Each block polymer in the multi-block copolymer may be a homopolymer block or a copolymer block.

The term“cationic block” generally relates to a block polymer which are present as positively charged ion, or which are capable of forming positively charges in aqueous media.

The term“nonionic block” generally related to a block polymer which lacks the ability to dissoci- ated in aqueous media into positively and negatively charged species.

The term“number average molecular weight” generally refers to any number average molecular weight (M,,) as calculated by the formula well-known in the prior art or measured according to any published method such as gel permeation chromatography (GPC).

The term“degree of polymerization” (DP) refers to the number of repeating units in an average polymer chain.

The term“charge density” refers to the ratio of the number of positive charges on a monomeric unit of which a polymer is comprised to the molecular weight of said monomeric unit.

The term“sulfate-based anionic surfactant” refers to the anionic surfactant having sulfate (- OSO₃ ^·) group; the term“sulfonate-based anionic surfactant” refers to the anionic surfactant hav- ing sulfonate (-SO₃ ) group; the term“carboxylate-based anionic surfactant” refers to the anionic surfactant having carboxylate (-COO or -COOH) group. The term“water-soluble” means that the polymer is soluble in water in the present formulation.

In general, the polymer should be soluble at 25° C at a concentration of 0.1 % by weight of the water solvent, preferably at 1 %, more preferably at 5%, most preferably at 15%.

According to the present invention, the multi-block copolymer comprises more than three blocks, including at least a block A and a block B, wherein the block A is a cationic block, and the block B is a nonionic block.

In a preferred embodiment, the nonionic block B is composed of water-soluble/hydrophile nonionic monomers. The resulting multi-block copolymer comprising water-soluble/hydrophile nonionic monomers may also exhibit hydrophilic properties such that it is soluble in aqueous media.

In some embodiments, the multi-block copolymer is a linear block copolymer. By linear it is meant that the block arrangement is linear. Preferably, the multi-block copolymer comprises at least five blocks. In some embodiments, the multi-block copolymer is a penta-block copolymer which constitutes a molecular structure of (block A)-(block B)-(block A)-(block B)-(block A); in some embodiments, the multi-block copolymer is a hexa-block copolymer which constitutes a molecular structure of (block A)-(block B)-(block A)-(block B)-(block A)-(block B); in still another embodiment, the multi-block is a hept-block copolymer which constitutes a molecular structure of (block A)-(block B)-(block A)-(block B)-(block A)-(block B)-(block A).

Preferably, at least one end of the multi-block copolymer is the cationic block. More preferably, each end of the multi-block copolymer that is either linear or branched is the cationic block A.

In some embodiments, the multi-block copolymer is a branched/crosslinked block copolymer by introducing branches (“arms”) on the linear copolymer or crosslink multiple linear copolymers. In some embodiments, the multi-block copolymer is a star-branched copolymer which comprises a polymeric core and at least two polymeric arms attached to the core, preferably the star- branched copolymer comprises a polymeric core and from 3 to 8 polymeric arms, more prefera- bly, the star-branched copolymer comprises a polymeric core and from 4 to 6 polymeric arms. In some embodiments, the“core” is the cationic block A. In some embodiment, the“arm” is a di- block copolymer comprising (block A)-(block B).

The multi-block copolymer can optionally comprise further cationic and/or nonionic blocks.

The term“degree of polymerization" as used herein may be defined as the number of monomer units in one polymeric block. A cationic block has a degree of polymerization (DP) of from about 5 to about 500, or about 10 to about 400, or about 20 to about 300, or about 30 to about 150, preferable about 60 to about 120. Individually or collectively, the cationic block(s) will present a net positive charge. In some embodiments, the cationic block comprises polymerized monomer residue units that each comprises positive charge. The molecular weight of the multi-block copolymer is the sum of each block. The multi-block copolymer has a number-average molecular weight (M,,) in a range from 10,000 to 1 ,000,000 g/mol, preferably from 20,000 to 500,000 g/mol, more preferably from 30,000 g/mol to 200,000 g/mol. Within these ranges, the weight ratio of each block may vary. It is however preferred that each block has a molecular weight above 2000 g/mol, and preferably above 5000 g/mol.

The multi-block copolymer has a charge density of between 0.5 and 8 meq/g. Preferably, the multi-block copolymer has a charge density of between 1.0 and 4.0 meq/g. Preferably, the multi- block copolymer has a charge density of between 1.5 and 3.5 meq/g. Preferably, the multi-block copolymer has a charge density of between 2.0 and 3.0 meq/g. In the present invention, the charge density (CD) is calculated from the cationic substitution and defined in milliequivalents per gram (meq/g) describing the amount of cationic charge per gram of polymer, which is de- termined according to the following formula:

Charge density (CD) (meq/g) = (%> A)/(% AX M_WA + % B X M_WB) *1000

in which: % A represents the molar percentage of the cationic monomer of block A

% B represents the molar percentage of the nonionic monomer of block B Mw A represents the molar mass of the cationic monomer of block A, g/mol Mw B represents the molar mass of the nonionic monomer of block B, g/mol

The charge density of the multi-block copolymer of the present invention therefore depends on proportions of cationic monomers and their respective molar masses. The degree of polymeri- zation (DP) of the nonionic block can be varied and adjusted to achieve the desired charge density. The charge density value can be also measured using conventional techniques known in the art. The charge density value obtained by experiments is close to the theoretical value, in particular in a range of pH 4.5 to 9.

According to any one of the embodiments of the present invention, each block A and B may vary in length and can vary in repeat sequence.

The multi-block copolymer comprises a block A, wherein the block A is cationic block compris- ing repeating units deriving from cationic monomers. Preferably, the cationic monomers are those bearing an ammonium group of formula -NR3⁺, wherein R, which is identical or different, represents a hydrogen atom, an alkyl group comprising 1 to 10 carbon atoms, or a benzyl group, optionally carrying a hydroxyl group, and comprise an anion (counter ion). Example of anions are halides such as chloride and bromides, sulphates, hydrosulphates, alkylsuphates, phosphates, citrates, formats, and acetates.

Example of the cationic monomers include but not limit to (meth)acrylate, (meth)acrylamides aminoalkyl (meth)acrylates, aminoalkyl (meth)acrylamides monomers, which comprise at least one primary, secondary, tertiary or quaternary amine function, or a heterocyclic group contain- ing a nitrogen atom; vinylamine; ethylenimine and diallyldialkyl ammonium salts; their mixtures, their salts, their derivatives and macromonomers deriving from therefrom.

Preferably, the cationic monomers can be dimethylaminoethyl (meth)acrylate, dimethyla- minopropyl (meth) acrylate, di-tert-butylaminoethyl (meth)acrylate, dimethylaminomethyl (meth)acrylamide, dimethylaminopropyl (meth)acrylamide, 2-vinylpyridine, 4-vinylpridine, (3- acrylamidopropyl) trimethyl-ammonium chloride (APT AC), [2-(methacryloyloxy)ethyl-ammonium chloride (MAETMAC), [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETMAC), [3- (methacryloylamino) propyl] trimethylammonium chloride (MAPTAC), diallyldimethylammonium chloride (DADMAC), 3-methyl-1-vinyl-1 H-imidazolium chloride (QVI-MeCI), 3-methyl-1 -vinyl-1 H- imidazolium-methyl-sulfate (QVI-DMS), dimethylammonium ethyl (meth)acrylate benzyl chlo- ride, trimethyl ammonium ethyl (meth)acrylate chloride, trimethyl ammonium propyl

(meth)acrylate chloride, trimethyl ammonium ethyl (meth)acrylamido chloride, trimethyl ammo- nium propyl (meth)acrylamido chloride, trimethylammonium ethyl acrylate methyl sulfate, ben- zyldimethylammoniumethyl (meth)acrylate chloride, vinylbenzyl trimethyl ammonium chloride and/or a mixture thereof.

The multi-block copolymer comprises a block B, wherein the block B is nonionic block compris- es repeating units deriving from nonionic monomers. Preferably, the nonionic block comprises repeating units deriving from water-soluble or hydrophilic nonionic monomers. Example of nonionic monomers include but not limit to ethylene oxide, hydrophilic esters derived from (meth)acrylic acid, vinyl alcohol, vinyl pyrrolidone, acrylamide, methacrylamide, ethylene oxide (meth)acrylate, polyethylene oxide (meth)acrylate, N,N-dimethylacrylamide, N,N- diethylacrylamide, vinylcaprolactam, hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxyalkylesters of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monocarboxylic acids, such as 2-hydroxyethylacrylate and hydroxyalkylamides of alpha-ethylenically-unsaturated, preferably mono-alpha- ethylenically-unsaturated, monocarboxylic acids.

The block A and the block B, respectively, may further comprise additional ethylenically unsatu- rated monomer (comonomer). In some embodiments, the block A may be copolymer comprising several kinds of cationic monomeric units and the block B may be copolymer comprising several kinds of nonionic monomeric units.

There are several methods for making the multi-block copolymer comprising the block A and the block B. In the context of the present invention, it is recommended to use living polymerization. Living polymerization is generally considered in the art to be a form of chain polymerization in which irreversible chain termination is substantially absent. An important feature of living polymerization is that polymer chains will continue to grow while monomer and reaction condi- tions to support polymerization are provided. Polymer chains prepared by living polymerization can advantageously exhibit a well-defined molecular architecture, a predetermined molecular weight and narrow molecular weight distribution or low dispersity. Examples of living polymerization include ionic polymerization and controlled radical polymeri- zation. Examples of controlled radical polymerization include, but not limited to, iniferter polymerization, nitroxide-mediated radical polymerization (NMP), atom transfer radical polymer- ization (ATRP), and reversible addition fragmentation chain transfer polymerization (RAFT). Preferably, the multi-block copolymer is prepared by using reversible addition fragmentation chain transfer polymerization (RAFT).

Equipment, conditions and reagents for performing living polymerization or controlled radical polymerization are well known to those skilled in the art.

Atom transfer radical polymerization (ATRP) process generally employs a transition metal cata- lyst to reversibly deactivate a propagating radical by transfer of a transferable atom or group such as a halogen atom to the propagating polymer chain, thereby reducing the oxidation state of the metal catalyst, according to the teaching of U.S. patent application US 2015/0024488.

Nitroxide-mediated radical polymerization (NMP) has been described as a simple, versatile and efficient controlled radical polymerization process. See, e.g., C. J. Hawker et al.,“New Polymer Synthesis by Nitroxide Mediated Living Radical Polymerizations”, Chemical Reviews, 2001 , pp. 3661-3688. NMP processes employ an alkoxy amine as an initiator to produce a polymeric radi cal in the presence of a monomer.

According to any one of the embodiments of the present invention, the multi-block copolymer may be prepared by using reversible addition fragmentation chain transfer polymerization (RAFT). RAFT polymerization is well known in the art. This method makes it possible to prepare polymers with a narrow dispersity and in which the length and the composition of the blocks are controlled by the stoichiometry and the degree of conversion. A polymer formed by RAFT polymerization may conveniently be referred to as a RAFT polymer. Such polymers will corn- prise residue of the RAFT agent that facilitated polymerization of the monomer. RAFT agents suitable for use in accordance with the invention comprise a thiocarbonylthio group (which is a divalent moiety represented by: -C(S)S-). Examples of RAFT agents are described in Moad G.; Rizzardo, E; Thang S, H. Polymer 2008, 49, 1079-1 131 and Aust. J. Chem., 2005, 58, 379-410; Aust. J. Chem., 2006, 59, 669-692; Aust. J. Chem., 2009, 62, 1402-1472, and include xanthate, dithioester, dithiocarbamate and trithiocarbonate compounds.

In some embodiments, the multi-block copolymer is prepared by a fast RAFT process as de- fined by the paper“Gody, G., et al. (2015). Polymer Chemistry 6(9): 1502-151 1” and“Gody, G., et al. (2014). Macromolecules 47(10): 3451-3460”. In a fast RAFT process, each block is pro- duced towards a high conversion (>90%) so that chain extension takes place directly by adding the next monomer, without purification in-between. Meanwhile, a high livingness of each step (>90%) is maintained to ensure the formation of high yield multi-block copolymer. A judicious play of polymerization temperature, initiator type, and concentration ratio between RAFT agent and initiator could fulfill both high conversion and high livingness in a short time by people skilled in the art, leading to a significant reduction of total polymerization time which is less than 24h, preferably less than 8h, more preferably less than 4h. The theoretical livingness can be estimated as the molar ratio of RAFT agent to the sum of RAFT agent and decomposed initia tor. The decomposition of initiator follows the equation: [l]_t/[l]o=exp(-k_dt), where [l]_t is concentra- tion of initiator during polymerization time t, [l]₀ is initial concentration (t=0) of initiator, k_d is kinet- ic constant of initiator decomposition, t is polymerization time.

In some preferred embodiments, polymerization temperature is about 60 to 80 °C, more prefer- ably 70 °C, and polymerization time for each block is 30-60 min, where monomer conversion reaches 93% - 99.6%. The initiator is water-soluble azo initiator having low decomposition tem- perature; preferably having a half-life of 10h at a temperature between 40 and 90 °C. The pre- ferred initiators include azo amide, azo nitrile, azo amidine and azo imidazoline. The concentra- tion ratio between the RAFT agent and initiator ranges from 5 to 100, preferably from 10-30, giving a theoretic livingness of 91 - 98% for each step. The total polymerization time is 3.5h to generate a penta-block copolymer.

In some preferred embodiments, the RAFT agent used is a symmetric RAFT agent. A symmet- ric penta-block copolymer can be prepared via the fast RAFT polymerization process with three polymerization and chain extensions, instead of five polymerization steps. A symmetric hepta- block copolymer can be prepared via the fast RAFT process with four polymerization and chain extensions, instead of seven polymerization steps. The total polymerization time is 3h to gener- ate a hepta-block copolymer.

Linear block copolymer may be prepared by living or controlled radical polymerization compris- ing the steps of:

a) Reacting a mono-alpha-ethylenically-unsaturated monomer, at least a free radical source compound, and a transfer agent, to obtain a first block, the transfer agent being bounded to said first block,

b) Reacting the first block, another mono-alpha-ethylenically-unsaturated monomer, and optionally, at least a radical source compound, to obtain a di-block copolymer,

Repeating n times (n being equal to or greater than 0) step b) to obtain a (n+2)-block copoly- mer.

The branched copolymer may be prepared by using crosslinking agent to connect the linear block polymer or form branches. The star-branched copolymer can be synthesized via either core-first method or core-last method. In a core-last method, a linear block polymer having a reaction point at one end (for example a polymerization end for a living polymerization) is pre- pared, followed by a method utilizing a crosslinking reaction of polyfunctional monomer to link the arms to the core part. The core-first method comprises using a polyfunctional initiator having plural functional groups each of which can initiate chain polymerization as a core, and allowing to grow a linear polymer to be the arm part. According to the any one of the embodiment of the present invention, the star-branched block copolymer comprises a central core block, on which the block copolymer arms are bonded by using a crosslinking agent. The crosslinking agent can be added during any step of polymeriza- tion/chain extension to form the branched multi-block copolymer. Preferably, the star-branched copolymer comprises a polymeric core and at least two polymeric arms attached to the core. Preferably, the“arm” is a di-block polymer comprising (block A)-(block B). Each two arms are connected by the core of block A to form a multiblock copolymer having the molecular structure of (block A)-(block B)-(block A)-(block B)-(block A).

The present invention also relates to use of the multi-block copolymer in forming a personal care composition. The present invention also relates to a method of preparing a personal care composition which comprises step of adding the multi-block copolymer in the composition. Par- ticularly, the present invention relates to a method for improving conditioning performance of a personal care composition by adding the multi-block copolymer in the composition.

The present invention further relates to a composition comprises the multi-block copolymer and at least one surfactant. According to any one of the invention embodiments, the composition comprises the multi-block copolymer and at least one anionic surfactant. Concentration of the multi-block copolymer ranges from 0.1 % to 2%, preferably from 0.2% to 1 %, more preferably 0.3% to 0.5% by weight relative to the total weight of thecomposition. Concentration of the sur- factant ranges from 1 % to 20%, preferably 4% to 15%, more preferably 8% to 15% by weight relative to the total weight of the composition.

Surfactants suitable in the present invention include those known in the art for use in personal care compositions, and include nonionic, anionic, cationic and amphoteric surfactants. Prefera- bly, the composition comprises the multi-block copolymer and at least one anionic surfactant. The anionic surfactant includes but not limited to, alkyl sulfates, alkyl ether sulfates alkylester sulfonates, alkylbenzene sulfonates, primary or secondary alkylsulfonates, alkylglycerol sul- fonates, sulfonated polycarboxylic acids, sulfates of alkylglycosides, sulfated alkyl amides, al- kylphosphates, the salts of saturated or unsaturated fatty acids, paraffin sulfonates, N-acyl N- alkyltaurates, isethionates, alkylsuccinamates, N-acyl sarcosinates, alkylsulfosuccinates, mo- noesters or diesters of sulfosuccinates, polyethoxycarboxylates.

Example of anionic surfactants include the following compounds:

The alkylsulfates of formula ROSO3M, where R represents an alkyl or hydroxyalkyl radical in C5- C24, preferably in C10-C18, M represents a hydrogen atom or a cation which is an alkaline cation (sodium, potassium, lithium), substituted or non-substituted ammonium (methyl-, dimethyl-, tri- methyl-, tetramethylammonium, dimethylpiperidinium...) or alcanolamine derivative (monoeth- anolamine, diethanolamine, triethanolamine...), as well as their ethoxylated (EO) and/or propoxylated (PO) derivatives, on average having from 0.5 to 30 units, preferably 0.5 to 10 EO and/or PO units. Examples of alkyl ether sulfates which may be used in the personal care corn- positions of the present invention include, but not limited to, sodium and ammonium salts of coconut alkyl triethylene glycol ether sulfate, tallow alkyl triethylene glycol ether sulfate, and tallow alkyl hexa- oxyethylene sulfate.

The alkylamide sulfate of formula RCON H ROSO3M , where R represents an alkyl radical in C2- C22, preferably in C6-C20, R’ an alkyl radical in C2-C3, M representing a hydrogen atom or a cati on of the same definition as above, as well as their ethoxylated (EO) and/or propoxylated (PO) derivatives, having on average from 0.5 to 60 EO and/or PO units.

The alkylester sulfonates of formula R-CH(S0₃M)-COOR’, wherein R represents an alkyl radical in C8-C20, preferably in C10-C16, R’ represents an alkyl radical in O-I-OQ, preferably C1-C3 and M is an alkaline cation (sodium, potassium, lithium), substituted or non-substituted ammonium (me- thyl-, dimethyl-, trimethyl-, tetramethylammonium, dimethylpiperidinium...) or alcanolamine de- rivative (monoethanolamine, diethanolamine, triethanolamine...).

The salts of saturated or unsaturated fatty acids in C8-C24, preferably in C14-C20, alkylbenzene- sulfonates in C9-C20, primary or secondary alkyl-sulfonates in C8-C22, alkylglycerol sulfonates, sulphonated polycarboxylic acids, paraffin sulfonates, N-Acyl N-alkyltaurates, alkylphosphates, isethionates, alkylsuccinamates, alkylsulfosuccinates, the monoester of diesters, of N-acyl sul- fosuccinate sarcosinates, the sulfates of alkylglycosides, polyethosylcarboxylates, the cation being an alkali metal (sodium, potassium, lithium), a substituted or non-substituted ammonium residue (methyl-, dimethyl-, trimethyl-, tetramethylammonium, dimethylpiperidinium...) or al- canolamine derivative (monoethanolamine, diethanolamine, triethanolamine...).

In the present invention, any surfactant having one or more -COO- groups may be used as the carboxylate anionic surfactant. Example of the carboxylate anionic surfactant are as follows:

(A) Fatty acid soap anionic surfactants having the formula: RCOOM wherein R represents an alkyl or alkenyl group having 8 to 24 carbon atoms, preferably 14 to 20 carbon atoms, M repre- sents one or more of alkali metals, organic amines, and basic amino acids (e.g., sodium laurate, potassium myristate, sodium oleate, sodium stearate, behenic acid triethanolamine salt);

(B) Ether carboxylate anionic surfactants having the formula: R(OCH CH )_xOCH COOM, where- in R represents an alkyl or alkenyl group having 8 to 22 carbon atoms, x is 0 or an integer of 1 to 16, and M represents one or more of alkali metals, organic amines, and basic amino acids (e.g., sodium polyoxyethylene (3 mol addition) lauryl acetate, sodium polyoxyethylene (6 mol addition) myristyl ether acetate);

(C) Another suitable anionic surfactant bearing carboxylate functional group may also be used in the present invention, which include but not limited to, N-acylsarcosinate anionic surfactant (e.g. potassium N-lauroylsarcosinate, N-stearoylsarcosinate triethanolamine salt), N- acrylglutamates, N-acyl-N-methyl-D-alanine salt anionic surfactant, N-acyl alanine salt anionic surfactant and the anionic surfactant bearing two or more carboxylate groups. Another suitable class of anionic surfactants are the water-soluble salts of the organic, sulfuric acid reaction products of the general formula R-SO₃-M, wherein R is chosen from the group consisting of a straight or branched chain, saturated aliphatic hydro-carbon radical having from 8 to 24, preferably 12 to 18, carbon atoms; and M is a cation. Important examples are the salts of an organic sulfuric acid reaction product of a hydrocarbon of the methane series, including iso-, neo-, ineso-, and n-paraffins, having 8 to 24 carbon atoms, preferably 12 to 18 carbon at- oms, and a sulfonating agent e.g., SO₃, H2SO4, oleum, obtained according to known sulfonation methods, including bleaching and hydrolysis. Preferred are alkali metal and ammonium sul- fonated Ci2-i8-n-paraffins.

Preferred anionic surfactants for use in the personal care compositions include ammonium lau- ryl sulfate, ammonium laureth sulfate, triethylamine lauryl sulfate, triethylamine laureth sulfate, triethanolamine lauryl sulfate, triethanolamine laureth sulfate, monoethanolamine lauryl sulfate, monoethanolamine laureth sulfate, diethanolamine lauryl sulfate, diethanolamine laureth sulfate, lauric monoglyceride sodium sulfate, sodium lauryl sulfate, sodium laureth sulfate, potassium lauryl sulfate, potassium laureth sulfate, sodium lauryl sarcosinate, sodium lauroyl sarcosinate, lauryl sarcosine, cocoyl sarcosine, ammonium cocoyl sulfate, ammonium lauroyl sulfate, sodium cocoyl sulfate, sodium lauroyl sulfate, potassium cocoyl sulfate, potassium lauryl sulfate, trieth anolamine lauryl sulfate, triethanolamine lauryl sulfate, monoethanolamine cocoyl sulfate, mo- noethanolamine lauryl sulfate, sodium tridecyl benzene sulfonate, sodium dodecyl benzene sul- fonate, disodium N-octadecyl sulfosuccinnate, disodium lauryl sulfosuccinate, diammonium lau- ryl sulfosuccinate, tetrasodium N-(1 ,2-carboxyethyl)-N-octadecyl sulfosuccinate, diamyl ester of sodium sulfosuccinic acid, dihexyl ester of sodium sulfosuccinic acid, dioctyl esters of sodium sulfosuccinic acid, the reaction products of fatty acids esterified with isethionic acid and neutral- ized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil or palm kernel oil, sodium or potassium salts of fatty acid amides of methyl tauride in which the fatty acids, for example, are derived from coconut oil or palm kernel oil; and/or combinations thereof.

In one embodiment, the personal care composition comprises the multi-block copolymer and at least one sulfate-based anionic surfactant. In this composition, the cationic block A of the multi- block polymer has a degree of polymerization (DP) in the range of 5 to 100, preferably 20 to 80, more preferably 30 to 60 ; the charge density (CD) of the multi-block copolymer is between 0.5 and 6 meq/g, preferably between 1 and 3 meq/g, more preferably between 1.5 and 2.5 meq/g.

In another embodiment, the personal care composition comprises the multi-block copolymer and at least one sulfonate-based anionic surfactant. In this composition, the cationic block A of the multi-block polymer has a degree of polymerization (DP) in the range of 10 to 200, prefera- bly 20 to 180, more preferably 30 to 150 ; the charge density (CD) of the multi-block copolymer is between 0.5 and 6 meq/g, preferably between 1.5 and 3.5 meq/g. In still another embodi- ment, the personal care composition comprises the multi-block copolymer and at least one car- boxylate-based anionic surfactant comprising one or more carboxylic or carboxylate functions (- COOH or -COO’). In this composition, the cationic block A of the multi-block polymer has a de- gree of polymerization (DP) in the range of 30 to 500, preferably 60 to 400, more preferably 100 to 300 ; the charge density (CD) of the multi-block copolymer is between 1 and 8 meq/g, pref- erably between 2 and 6.5 meq/g.

According to any one of the invention embodiments, the composition further comprises at least one cosurfactant which can be zwitterionic, nonionic or anionic surfactant. Concentration of such cosurfactants ranges from about 0.1 % to 10%, preferably 1 % to 8%, more preferably 3% to 5% by weight of the total weight of the composition. Non-limiting examples of suitable zwitter- ionic or amphoteric surfactants as cosurfactants are described in U.S. Pat. Nos. 5,104,646 (Bolich Jr. et al.), 5,106,609 (Bolich Jr. et al.), which descriptions are incorporated herein by reference.

Amphoteric surfactants suitable for use in the personal care composition are well known in the art, and include those surfactants broadly described as derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be straight or branched chain and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic water solubilizing group such as carboxy, sulfonate, sulfate, phosphate, or phospho- nate. Preferred amphoteric surfactants for use in the present invention include cocoamphoace- tate, cocoamphodiacetate, lauroamphoacetate, lauroamphodiacetate, and mixtures thereof.

Zwitterionic surfactants suitable for use in the personal care composition are well known in the art, and include those surfactants broadly described as derivatives of aliphatic quaternary am- monium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight or branched chain, and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic group such as carboxy, sulfonate, sul- fate, phosphate or phosphonate. Zwitterionics such as betaines are preferred in the present invention.

Suitable cosurfactants include nonionic surfactants. Any such surfactant known in the art for use in hair or personal care products may be used, provided that the optional additional surfactant is also chemically and physically compatible with the essential components of the personal care composition, or does not otherwise unduly impair product performance, aesthetics or stability. Non-limiting examples of other surfactants suitable for use in the personal care compositions are described in McCutcheon's, Emulsifiers and Detergents, 1989 Annual, published by M. C. Publishing Co., and U.S. Pat. Nos. 3,929,678, 2,658,072; 2,438,091 ; 2,528,378, which descrip- tions are incorporated herein by reference.

The personal care compositions of the present invention may further comprise a mono or diva- lent salt. Suitable salts include, but are not limited to chlorides, phosphates, sulfates, nitrates, citrates and halides. The counter ions of such salts can be, but are not limited to, sodium, po- tassium, ammonium, magnesium, zinc or other mono and divalent cation. Electrolytes most pre- ferred for use in the compositions of the present invention include sodium chloride, ammonium chloride, sodium citrate, magnesium chloride, and magnesium sulfate. Concentration of such salt is preferably at a level of from about 0.01 % to about 5%, more preferably from about 0.05% to about 3.5%, and still more preferably from about 0.1 % to about 2% by weight of the total weight of the composition.

According to any one of the invention embodiments, the composition may comprise further compounds. The composition preferably comprises water, and is preferably an aqueous solu- tion, dispersion, suspension or emulsion, of multi-block copolymer and at least one surfactant.

The composition may comprise insoluble organic compounds which can be present in the form of particles which can also be mentioned include oils which can exert conditioning, protective or emollient functions; the oils are generally selected from alkylmonoglycerides, alkyldiglycerides, triglycerides such as oils extracted from plants and vegetables or oils of animal origin, deriva- tives of these oils such as hydrogenated oils, lanolin derivatives, mineral oils or paraffin oils, perhydrosqualane, squalene, diols such as 1 ,2-dodecanediol, cetyl alcohol, stearyl alcohol, ole- ic alcohol, fatty esters such as isopropyl palmitate, 2-ethylhexyl cocoate, myristyl myristate, or lactic acid esters of stearic acid, behenic acid isostearic acid. The composition may further comprise bactericidal or fungicidal agents to improve disinfection, anti-dandruff agents, insecti- cidal agents. The compositionof the present invention may further comprise additional optional ingredients which may bring specific benefits for the intended use. Such optional ingredients may include colorants, pearlescent agents, emollients, suspending agent, hydrating agents, opacifiers, preservatives and pH adjusters. The skilled person is able to select according to general knowledge in the art of formulating personal care compositions such as shampoos, shower gels, and the vast literature there-related, appropriate such optional ingredients for ap- plication purposes.

According to any one of the invention embodiments, the composition of the present invention further comprises one or more benefit agents, such as emollients, moisturizers, conditioners, skin conditioners, or hair conditioners such as silicones or non-amino silicones and mixtures thereof; vitamins or their derivatives; vitamins A,C,D,E,K and their derivatives; hair coloring agents; bleaching agents; hair bleaching agents; UV absorbers; anti-UV agents, antimicrobial agents, antibacterial agents; antifungal agents, melanin regulators, tanning accelerators, depigmenting agents, skin lightening agents; skin-coloring agents; weight-reduction agents; anti-acne agents, antiseborrhoeic agents, anti-ageing agents, anti-wrinkle agents, antibiotics, anti-inflammatory agents; botanical extracts; refreshing agents, cicatrizing agents; vascular- protection agents; agents for the reduction of dandruff; anti-psoriasis agents; agents for combat- ing hair loss; reducing agents for permanent-waving; immunomodulators; nourishing agents, depilating agents; essential oils and fragrances.

According to any one of the invention embodiments, the composition can be a cosmetic compo- sition. Such a composition can be formulated into a large number of types of products for the skin and/or hair, gels (in particular styling gels), conditioners, formulations for styling or to facili tate combing the hair, rinsing formulae, body and hand lotions, products regulating skin hydra- tion, toilet milks, make-up remover, shampoos, shower gels, liquid soaps and other composi- tions of similar type. In a more particular embodiment, the composition is a rinse-off cosmetic composition which is intended to be removed after application on skin, hair or mucous mem- branes of a human subject. Examples of the rinse off cosmetic compositions are a shampoo, a shower gel formulation, a liquid soap and a body wash.

The personal care composition of the present invention, in general, may be made by mixing the ingredients together at either room temperature or at elevated temperature, e.g., about 72°C. Heat only needs to be used if solid ingredients are in the composition. The ingredients are mixed at the batch processing temperature. Additional ingredients may be added to the product at room temperature.

The personal care compositions of the present invention can be used in a conventional manner for cleansing and conditioning hair or skin. An effective amount of the compositionfor cleansing and conditioning the hair or skin is applied to tire hair or skin, that has preferably been wetted with water, and then rinsed off. Such effective amounts generally range from about 1gm to about 50gm, preferably from about 1gm to about 20gm. Application to the hair typically includes working the composition through the hair such that most or all the hair is contacted with the composition. This method for cleansing and conditioning the hair or skin comprises the steps of: a) wetting the hair or skin with water, b) applying an effective amount of the personal care corn- position to the hair or skin, and c) rinsing the applied areas of skin or hair with water. These steps can be repeated as many times as desired to achieve the desired cleansing and condi- tioning benefit.

The present invention will now be described in further detail by way of the following non-limiting examples, wherein the abbreviations have the usual meaning in the art.

Examples

Materials description and source

3-Acrylamidopropyl-trimethylammonim chloride (APTAC): Sold by Sigma as 75% aqueous solu- tion

Acrylamide (AM): Sold by Sigma (prepared as 52% aqueous solution)

Asymmetric RAFT agent: 3-(((1-carboxyethyl)thio)carbonothioyl)thio)propanoic acid sold by Boron Molecular

Initiator: Wako VA044 sold by Wako (prepared as 1 % aqueous solution)

Surfactants: Texapon N70 (sulfate surfactant), Texapon SFA (sulfonate surfactant), Plantapon LCG sorb (carboxylate surfactant) sold by BASF

Co-surfactant: Dehyton PK45 sold by BASF

Example 1 : Synthesis of a penta-block copolymer using RAFT polymerization process The subject of Example 1 is the preparation of a penta-block copolymer comprising block A and block B using semi-batch process with an asymmetric RAFT agent 3-(((1- carboxyethyl)thio)carbonothioyl)thio)propanoic acid (Sold by Boron molecular); the block A is cationic poly((3-Acrylamidopropyl)trimethylammonim chloride) (APTAC) and the block B is poly(Acrylamide) (AM). The molar ratio of RAFT agent/monomer was chosen for a theoretical degree of polymerization of 33 for the block A and 220 for the block B at 100% conversion (See Table 1 below). The chemical structure of the penta-block copolymer thus represents: APTAC33- AM220-APTAC33-AM220-APTAC33. The polymer has a charge density of 2 meq/g according to the calculation formula defined in the above text.

The initial charge was prepared by dissolving the asymmetric RAFT agent in NaOH and adding the reagents in a reactor and mixed until all components were dissolved. The pH was adjusted to 5 with HCI. The system was under N₂ bubbling for 30 minutes and then heated to 70°C under N₂ atmosphere, to allow the polymerization. The feed 1 was added, and the polymerization was performed for 30 minutes. Then feed 2, feed 3 and feed 4 were simultaneously added for 10 minutes, and the polymerization was performed for 50 minutes. Then feed 5, feed 6 and feed 7 were added simultaneously for 5 minutes and the polymerization was performed for 25 minutes. Then feed 8, feed 9 and feed 10 were added simultaneously for 10 minutes and the polymeriza- tion was performed for 50 minutes. Finally feed 11 , feed 12 were added for 5 minutes and the polymerization was performed for 25 minutes. After a total of reaction time of each polymeriza- tion step, the conversion was above 93% as confirmed by ¹H-NMR analysis. The solid content of final polymer solution is 34.9 %.

_ Table 1 _

Semi-batch synthesis of penta-block copolymer

Initial charge 32.0 g Water,

0.51 g RAFT agent, and

18.19 g APTAC (75%)

Feed 1 _ 2. 16 g initiator VA044 (1 %)

Feed 2 _ 59.03 g AM (52%) _

Feed 3 6.35 g initiator VA044 (1 %)

Feed 4 40.0 g water

Feed 5 _ 18.19 g APTAC (75%)

Feed 6 2.16 g initiator VA044 (1 %)

Feed 7 15.0 g water

Feed 8 _ 59.03 g AM (52%) _

Feed 9 6.47 g initiator VA044 (1 %)

Feed 10 15.0 g water

Feed 1 1 18.19 g APTAC (75%)

Feed 12 3.20 g initiator VA044 (1 %) Molecular weight and polydispersity of polymers are determined by gel permeation chromatog- raphy (GPC) using 3 PSS NOVEMA Max analytical Ultrahigh columns and aqueous solution containing 0.1 % trifluoro acetic acid and 0.1 mol/L NaCI (pH=2) as eluent. The concentration of polymer is determined by refractive index detector and the molecular weight is calibrated by poly(2-vinylpyridine) standards.

The obtained penta-block copolymer has a number-average molecular weight (M„) of 24000 g/mol, polydispersity index of 1.76, which are determined by aqueous gel permeation chroma- tography with the condition as defined hereinabove.

Example 2: Synthesis of hepta-block copolymer using RAFT polymerization process

The subject of Example 2 is the preparation of a hepta-block copolymer comprising block A and block B; the block A is cationic poly((3-Acrylamidopropyl)trimethylammonim chloride) (APT AC) and the block B is poly(Acrylamide) (AM). The molar ratio of RAFT agent/monomer was chosen for a theoretical degree of polymerization of 33 for the block A and 220 for the block B at 100% conversion (See Table 2 below). The chemical structure of the penta-block copolymer thus rep- resents: APTAC33-AM220-APTAC33-AM220-APTAC33-AM220-APTAC33. The polymer has a charge density of 2 meq/g according to the calculation formula defined in the above text.

The hepta-block copolymer was synthesized by using semi-batch process with a symmetric RAFT agent S,S’-Bis(a,a’-dimethyl-a”-acetic acid)-trithiocarbonate (synthesized following the procedure described in“John T. Lai et al. (2002) Macromolecules 35(18):6754-6756”). The rea- gents of initial charge were added in a reactor and well mixed under stirring. pH was adjusted to 5 with HCI. The system was under N2 bubbling for 30 minutes and then heated to 70°C under N2 atmosphere, to allow the polymerization. The feed 1 was added for 15 minutes, and the polymerization was performed for additional 15 minutes. Then feed 2, feed 3 and feed 4 were added simultaneously for 20 minutes, and the polymerization was performed for 40 minutes. Then feed 5, feed 6 and feed 7 were added simultaneously for 5 minutes and the polymerization was performed for 25 minutes. Then feed 8, feed 9 and feed 10 were finally added for 20 minutes and the polymerization was performed for 40 minutes.

Table 2

Semi-batch synthesis of hepta-block copolymer

with a symmetric RAFT agent

Initial charge 34.0 g Water,

0.42 g RAFT agent, and

27.3 g APTAC (75%)

Feed 1 1.94 g initiator VA044 (1 %)

Feed 2 78.20 g AM (52%)

Feed 3 4.85 g initiator VA044 (1 %)

Feed 4 12.0 g water

Feed 5 27.30 g APTAC (75%)

Feed 6 6.06 g initiator VA044 (1 %)

Feed 7 32.0 g water

Feed 8 39.4 g AM (52%)

Feed 9 8.08 g initiator VA044 (1 %)

Feed 10 35.0 g water

After a total of reaction time of each polymerization step, the conversion was above 93% as confirmed by ¹H-NMR analysis. The dry extract of the final solution is 36.5 %. The obtained hep- ta-block copolymer has a number-average molecular weight (M„) of 31700 g/mol, polydispersity index of 1.47, which are determined by aqueous gel permeation chromatography with the same condition as defined in Example 1. Example 3: Synthesis of a branched multi-block copolymer

The branched multi-block copolymer was synthesized using core-last method in which the arm copolymer (APTAC-AM di-block) was firstly synthesized. The final multi-block copolymer was made by chain extension to the core polymer (APT AC block). The molar ratio of RAFT agent/monomer was chosen for a theoretical degree of polymerization of APT AC block of 33 and for a theoretical degree of polymerization of AM block of 220 at 100% conversion (See Ta- ble 3, Table 4 and Table 5 below).

Step 1 : Synthesis of arm block

APTAC, water, a RAFT agent 3-(((1-carboxyethyl)thio)carbonothioyl)thio)propanoic acid (sold by Boron molecule) (dissolved in a water/ethanol mixture) were added, with 2,2'-Azobis[2-(2- imidazolin-2-yl)propane] dihydrochloride (VA044), into a flask equipped with a magnetic stirrer, adjusting pH to 5 with HCI then cooling down the system with an ice bath and bubbling N₂ for 30 min. Then the mixture is thus heated for 5h to 45°C under N₂ atmosphere, to allow polymeriza- tion and obtain APTAC block. Table 3

mass of reagents introduced

ATPAC RAFT agent Initiator Water Ethanol

VA044

2.183 g 0.0641 g 0.0155 g 2.16 g 0.631 g

AM monomer, water and VA044 were then directly added to the 4.8ml aqueous solution con- taining APT AC block (from Table 3) under N₂ atmosphere. The system was heated to 45°C for 5h to allow the polymerization and obtain (APTAC-AM) block. The APTAC-AM block has num- ber average molecular weight of 18800 g/mol and polydispersity index of 1.24 which are meas- ured by gel permeation chromatography according to the same measurement defined for Ex- ample 1.

Table 4

mass of reagents introduced

APTAC block AM Initiator Water solution VA044

4.8 ml 3.753 g 0.0155 g 10.02 g

Step 2: Synthesis of the branched multi-block copolymer

APTAC, VA044, N, N’-methylene bis(acrylamide) (Sold by Sigma) as crosslinking agent and water were added to a reaction tube comprising 2ml aliquot of the solution containing APT AC- AM block obtained in step 1. The system was bubbled with N₂ and heated to 45°C for 10h to allow the polymerization of branched copolymer.

Table 5

mass of reagents introduced

Solution contain- APTAC N, N’- Initiator Water ing Am-APTAC methylene VA044

arm bis(acrylamide)

2 ml 0.141 g 0.0789 g 0.00345 g 5.86 g

After a total of reaction time of each polymerization step, the conversion was above 94% as confirmed by ¹H-NMR analysis. The branched multi-block copolymer has number average mo- lecular weight of 135000 g/mol and polydispersity index of 1.39 which are measured by gel permeation chromatography according to the same measurement defined for Example 1. The dry extract of the final solution is 31.8 %.

Example 4: Synthesis of a penta-block copolymer

The subject of Example 4 is the preparation of a penta-block copolymer which was prepared in a manner similarly described hereinabove in Example 1.

The penta-block copolymer comprising block A and block B; the block A is cationic poly((3- Acrylamidopropyl)trimethylammonim chlodride) (APTAC) and the block B is poly(Acrylamide) (AM). The molar ratio of RAFT agent/monomer was chosen for a theoretical degree of polymeri- zation of 66 for the block A and 440 for the block B at 100% conversion; The chemical structure of the penta-block copolymer thus represents: APTAC66-AM440-APTAC66-AM440-APTAC66-AM440- APTAC₆₆. The polymer has a charge density of 2 meq/g according to the calculation formula defined in the above text.

Example 5: Synthesis of a penta-block copolymer

The subject of Example 5 is the preparation of a penta-block copolymer which was prepared in a manner similarly described hereinabove in Example 1.

The penta-block copolymer comprising block A and block B; the block A is cationic poly((3- Acrylamidopropyl)trimethylammonim chlodride) (APTAC) and the block B is poly(Acrylamide) (AM). The molar ratio of RAFT agent/monomer was chosen for a theoretical degree of polymeri- zation of 132 for the block A and 880 for the block B at 100% conversion. The chemical struc- ture of the penta-block copolymer thus represents: APTAC132-AM880-APTAC132-AM880- APTACI32-AM₈₈O-APTAC 132. The polymer has a charge density of 2 meq/g according to the cal- culation formula defined in the above text.

Comparative Examples

The comparative examples are comparative copolymers having the same monomer combina- tion and ratio. Random copolymers were synthesized by conventional radical polymerization, using commonly used initiator known in the art and polymerized at 70°C for 3h.

Gradient copolymer and block copolymer were synthesized by RAFT polymerization process. The polymerization degree is controlled by the ratio of monomer concentration ([M]) versus RAFT agent concentration ([RAFT]). The block copolymer was made in two steps via chain ex- tension. An asymmetric RAFT agent, 3-((((1-carboxyethyl)thio)carbonothioyl)thio)propanoic acid (sold by Boron Molecular), was used for synthesizing di-block copolymer, and a symmetric RAFT agent S,S’-bis(a,a’-dimethyl-a”-acetic acid)-trithiocarbonate (synthesized following the procedure described in“John T. Lai et al. (2002) Macromolecules 35(18):6754-6756”), was used for synthesizing tri-block copolymer. Each polymerization was performed at 45°C for 5h, using the initiator (Wako VA044, from Wako). The synthetic conditions of comparative polymers are detailed in Table 6. Table 6

Synthetic conditions for comparative polymers

Polymers [APTAC]/M [AM]/M [RAFT]/mM [l]/mM

Random copolymer A 0.16 0.70 NA 0.58

Random copolymer B 0.16 0.70 NA 8.75

Gradient copolymer C 0.45 1.98 0.3 0.15

Gradient copolymer D 0.29 1.27 0.79 0.39

AB block copolymer E (AP- Am block NA 4.4 10 2.5

TACiooAm₄₄o) APTAC block 0.4 NA 4 1

AB block copolymer F (AP- APTAC block 1 NA 2 0.5

TAC5ooAm22oo) Am block NA 2.2 1. 0.25

ABA block copolymer G APTAC block 1.2 NA 2.4 0.6

(APT AC25oAm22ooAPT AC250) Am block NA 1.76 0.8 0.2

ABA block copolymer H APTAC block 1.58 NA 24 1.2

(APT AC Arri oAPT AC33) Am block NA 1.74 6 1.5

NA: not applicable Preparation of a shampoo composition

A standard shampoo was prepared by diluting the penta-block copolymer of Example 1 solution with water, addition of the surfactant (Texapon N70 from BASF) and co-surfactant (Dehyton PK45 from BASF), followed by addition of required amount of NaCI. The pH was adjusted with citric acid on pH =6.0.

The same procedure was used for preparing of a shampoo composition for the multi-block co- polymers obtained from Example 2, Example 3, Example 4 and Example 5.

The same procedure was used for preparing of a shampoo composition comprising the copoly- mer of comparative examples.

The shampoo composition is shown in detailed in Table 7.

Table 7

Shampoo composition

Ingredients % by weight

Copolymer 0.5

Anionic surfactant 10

Co-surfactant 4

NaCI 1

Water 84.5 Observation of coacervate formation

The term“coacervate” as used herein, refers to the physicochemical complex formed between cationic polymer and surfactant component within the personal care formulation upon dilution of the personal care formulation.

It is believed to be particularly advantageous for the multi-block copolymer to be present in the personal care formulation in a coacervate phase, or to form a coacervate phase upon applica- tion or rinsing of the personal care formulation to or from the hair. Complex coacervates are believed to more readily deposited on the hair. Thus, in general, it is preferred that the multi- block copolymer exist in the personal care formulation as a coacervate phase or form a coacer- vate phase upon dilution.

Techniques for analysis of formation of complex coacervates are known in the art. For example, The coacervate behaviour can be observed visually upon stepwise dilution of the formulation, at any chosen stage of dilution, to identify whether a coacervate phase has formed. Four differ ent states could be observed during the dilution:

(a) No obvious change in turbidity: the formulation keeps turbid

(b) No obvious change in turbidity: the formulation keeps clear

(c) An increase in turbidity: the formulation turns from clear (translucent) to turbid

(d) A decrease in turbidity: the formulation turns from turbid to clear (translucent)

The states (c) is regarded as coacervation behaviour which means that coacervate phase is formed. Such phases can broadly be considered coacervates and existence of floes due to physicochemical complex formed between cationic polymer and surfactant.

Wet combing test

The wet combing properties were measured according to SGS Fresenius standardized study setup: 5 hair strands per shampoo sample (black hair, available from International Hair Import- ers (I HI P, New York)) were used for the determination of combing forces. All hair strands were defined damaged by professional hair bleach. The hair strands were pre-conditioned in water and washed with a 12% Sodium laureth sulfate (SLES) solution. The wet combing force was measured immediately after washing. The combing force of the hair was measured using a ten- sile testing machine (Zwick Z 1.0/TN1 SSO) resulting in the value for the untreated hair strands. Then the hair strands were then treated twice with a test item (shampoo; 0.5ml/g hair), foamed for 1 min and left to rest for additional 2 min. After each foaming phase the test product was rinsed off for 1 min with water. Again, the wet combing force was measured immediately after washing.

The average work is calculated from the surface below the force-path plot in the measuring in- terval between 20 and 120 mm. The relative combing force (RCF) is calculated from the value of the untreated hair strands W₀ and the value of the treated hair strands W, according following expression: RCF[%] = (Wo-Wi)/Wo. Negative values show a reduction in combing force, positive an increase. Table 8: Results of the coacervate formation and relative combing force. Table 8

Coacervation behaviour and relative combing force (RCF) measured for hair

strands treated by shampoo compositions containing multi-block Copolymer and comparative polymers

Copolymers K value Coacervate for- RCF (%)

mation

Example 1 51 Yes 45

Penta-block copolymer (AP-

TAC33AM220APTAC33

AM220APTAC33)

Example 2 57 yes 42

Hepta-block copolymer

(APT AC₃₃AM₂₂₀APT AC₃₃

AM220APTAC33AM220APTAC33)

Random copolymer A 149 Yes 46

Random copolymer B 85 Yes 75

Gradient copolymer C 116 Yes 83

Gradient copolymer D 71.5 Yes 96

AB block copolymer E (AP- ND No, all turbid 115

TAC100AM440)

AB block copolymer F (AP- 87 No, all turbid 103

T AC₅₀₀AM ₂₂₀₀)

ABA block copolymer G (AP- 86 No, all turbid 95

T AC₂₅₀AM₂₂₀₀APT AC₂₅₀)

ABA block copolymer H (AP- ND No, all clear ND

TAC33AM290APTAC33)

ND: not determined Superior conditioning effect can be quantified as a reduction in combing force, as measured in terms of relative combing force, described hereinabove. The“K value” was used as the parame- ter for characterizing the molecular weight and measured by the method described in Ή.

Fikentscher, Cellulosechemie 13 (1932), 58” using a polymer concentration of 0.1 wt.% in 3% NaCI solution.

The results expressly show that, among shampoo compositions containing various kinds of co- polymers, when the molecular weight (K value) increases, the relative combing force (RCF%) decreases which demonstrates a better conditioning effect. The results also expressly illustrate that only the shampoo compositions containing the in- ventive multi-block copolymers (Example 1 & Example 2), lead to the best conditioning perfor- mance along with observation of coacervate formation and a significant decrease of combing force, meanwhile at lowest level of molecular weight.

The combing force properties were also measured for hair strands treated by shampoo compo- sition comprising the branched multi-block copolymer and the arm copolymer (APTAC-AM di- block copolymer) obtained in Example 3 (See Table 9 below).

_ Table 9 _

Relative combing force (RCF) measured for hair strands treated by

shampoo compositions containing the branched multi-block copolymer and the arm copolymer (di-block copolymer)

Copolymers RCF (%)

Example 3 57

Branched penta-block copolymer

Arm copolymer (di-block) 115

The result expressly demonstrates that the shampoo composition comprising the inventive mul- ti-block copolymer having branched structure, brings about a better conditioning effect with a significant decrease of combing force.

The combing force properties were also measured for hair strands treated by shampoo compo- sitions comprising the penta-block copolymer having varied cationic block lengths (DP) and nonionic block lengths obtained in Examples 1 , 4 and 5. Different types of anionic surfactant including sulfate-based, sulfonated-based and carboxylate-based anionic surfactants were used in forming the shampoo composition (See Table 10 below). The shampoo compositions were preparing in a manner similarly described hereinabove.

Table 10

Relative combing force (RCF) measured for hair strands treated by shampoo composi- tions containing the penta-block polymers with varied block DP and different anionic surfactants

Composition Composition Composition with sulfate with sul- with carbox-

Penta-block copolymers

surfactant fonate sur- ylate surfac- factant tant

RCF (%)

Example 1

(AT P AC ₃₃ AM ₂₂₀APT AC₃₃ AM ₂₂₀APT AC ₃₃) 45 35 82

(K value = 51)

Example 4

(ATPAC66AM440APTAC66AM440APTAC66) 54 37 59

(K value = 62)

Example 5

(ATPAC132AM880APTAC132AM880APTAC132) ND 57 36

(K value = 71)

ND: not determined The advantageous conditioning effect is observed by using the inventive multi-block copoly- mers, having a broad range of polymerization degree (DP) of cationic block, in various shampoo compositions.

Notably, the penta-block copolymer of Example 1 having low cationic block DP leads to good conditioning performance with reductions in combing force for all the compositions, in particular when forming the shampoo composition with sulfate-based and sulfonate-based anionic surfac- tants. The penta-block copolymer of Example 4 having medium cationic block DP leads to satis- factory conditioning effect with significant decreases of combing force for all three shampoo compositions. The penta-block copolymer of Example 5 having high cationic block DP leads to better conditioning performance with significant decreases of combing force for the composition comprising sulfonate-based surfactant and carboxylate-based surfactant, in particular the best conditioning result was obtained with the carboxylate-based composition.

The results expressly exhibit that use of shorter cationic block length leads to better conditioning performance when being used in combination with sulfate-based and/or sulfonate-based anionic surfactants; moderate level of cationic block length contributes satisfied conditioning results with all types of anionic surfactants; and longer cationic block length brings about better effect when being used with carboxylate-based surfactant in shampoo composition. Preparation of shampoo composition containing silicone oil

A standard shampoo composition was prepared in a manner similarly described hereinabove with addition of dimethicone emulsion. The shampoo composition was prepared with addition of the multi-block copolymer (Example 1). The comparative polymer random copolymer A de- scribed in Table 8 and commercial cationic guar (Jaguar® C13 S, sold by Solvay) were also used to prepare the shampoo compositions as comparative examples.

The shampoo composition is shown in detailed in Table 1 1. _ Table 1 1 _

Ingredient % by weight

Copolymer 0.5

Sodium lauryl ethsulfate (SLES) 10

Cocamidopropyl betaine (CAPB) 4

Dimethicone 2

NaCI _ 1 _

Water 82.5

Silicone deposition measurement and results

Shampoo compositionmay typically comprise a conditioning agent such as silicone. The sham- poo composition comprises the inventive multi-block copolymer may also provide sufficient deposition of conditioning agent onto hair/skin surface.

Methodologies for measuring or otherwise identifying improved silicone deposition on hair or other surfaces are well-known in the art. The method adopted in the present invention refers to that described in U.S. patent 8663613 B2.

The results of silicone deposition are shown in Table 12. The term“ppm” as used herein refers to parts per million.

_ Table 12 _

Copolymer Silicone deposition (ppm)

Example 1 3321

Multi-block copolymer (AP- T AC₃₃Arri₂₂oAPT AC₃₃Arri₂₂oAPT AC₃₃)

Random copolymer A 448

Cationic guar 851

The results clearly demonstrate that the shampoo compositionwhich contains the inventive mul- ti-block copolymer deposits significantly more silicone onto a surface of hair than the other compositions which contain comparative random copolymer A and commercial cationic guar polymer.

Claims

1. A multi-block copolymer comprising more than three blocks, including at least a block A and a block B; wherein the block A is a cationic block, and the block B is a nonionic block.

2. The multi-block copolymer according to claim 1 , wherein the cationic block has a degree of polymerization of from 5 to 500; preferably from 10 to 400; more preferably from 20 to 300.

3. The multi-block copolymer according to claim 1 or 2, wherein the cationic block comprises repeating units deriving from monomers selected from the group consisting of: (meth)acrylates, (meth)acrylamides, aminoalkyl (meth)acrylates, aminoalkyl (meth)acrylamides monomers, which comprise at least one primary, secondary, tertiary or quaternary amine function; a hetero- cyclic group containing a nitrogen atom; vinylamine; ethylenimine and diallyldialkyl ammonium salts; their mixtures, their salts, their derivatives and macromonomers deriving from therefrom.

4. The multi-block copolymer according to any one of claims 1 to 3, wherein the nonionic block comprises repeating units deriving from water-soluble or hydrophilic nonionic monomers.

5. The multi-block copolymer according to any one of claims 1 to 4, wherein the multi-block copolymer is a linear copolymer, a copolymer having a star structure, a copolymer having a comb structure, a dendritic copolymer or a hyperbranched copolymer.

6. The multi-block copolymer according to any one of claims 1 to 5, wherein the multi-block copolymer comprises at least five blocks, wherein the said multi-block copolymer can be a pen- ta-block copolymer constituting a molecular structure of (block A)-(block B)-(block A)-(block B)- (block A); a hexa-block copolymer constituting a molecular structure of (block A)-(block B)- (block A)-(block B)-(block A)-(block B); or a hept-block copolymer constituting a molecular struc- ture of (block A)-(block B)-(block A)-(block B)-(block A)-(block B)-(block A).

7. The multi-block copolymer according to any one of claims 1 to 6, wherein each end of the multi-block copolymer is the cationic block.

8. The multi-block copolymer according to any one of claims 1 to 7, further comprises other ethylenically unsaturated monomers.

9. The multi-block copolymer according to any one of claims 1 to 8, has a number-average molecular weight in the range of 10,000 g/mol to 1 ,000,000 g/mol, wherein the molecular weight is calculated for the sum of each block.

10. The multi-block copolymer according to any one of claims 1 to 9, wherein the multi-block copolymer has a charge density between 0.5 and 8 meq/g, preferably between 1.0 to 4.0 meq/g, more preferably between 1.5 to 3.5 meq/g in the range of pH 4.5 to 9.

11. A process for preparation of the multi-block copolymer according to any one of claims 1 to 10 , wherein the multi-block copolymer is prepared by a living or controlled free-radical polymer- ization process.

12. The process according to claim 11 , wherein the living or controlled free-radical polymeri- zation process can be reversible addition-fragmentation chain transfer (RAFT).

13. The process according to claim 11 or 12, wherein the total polymerization time of the pro- cess is less than 24h; the monomer conversion for each polymerization and chain extension is more than 90%; and theoretically livingness is more than 90% for each polymerization step.

14. The process according to any one of claims 1 1 to 13, wherein the concentration ratio be- tween RAFT agent and initiator ranges from 5 to 100.

15. Use of the multi-block copolymer according to any one of claims 1 to 10 in forming a per- sonal care composition.

16. A method for improving conditioning performance of a personal care composition, corn- prising one step of adding in the composition the multi-block copolymer according to any one of claims 1 to 10.

17. A composition comprising a multi-block copolymer according to any one of claims 1 to 10 and at least one surfactant.

18. The composition according to claim 17, wherein the surfactant is anionic surfactant, which can be selected from the group consisting of: alkyl sulfates, alkyl ether sulfates, alkylester sul- fonates, alkylbenzene sulfonates, primary or secondary alkylsulfonates, alkylglycerol sulfonates, sulfonated polycarboxylic acids, sulfates of alkylglycosides, sulfated alkyl amides, al- kylphosphates, the salts of saturated or unsaturated fatty acids, polyoxyalkylene ether acetate, paraffin sulfonates, N-acyl N-alkyltaurates, isethionates, alkylsuccinamates, N-acyl sar- cosinates, alkylsulfosuccinates, monoesters or diesters of sulfosuccinates, polyethoxycarbox- ylates and a combination thereof.

19. The composition according to claim 17 or 18, comprising the multi-block copolymer and at least one sulfate-based anionic surfactant, wherein the cationic block A of the multi-block copol- ymer has a degree of polymerization in the range of 5 to 100, preferably 20 to 80, more prefera- bly 30 to 60.

20. The composition according to claim 17 or 18, comprising the multi-block copolymer and at least one sulfonate-based anionic surfactant, wherein the cationic block A of the multi-block copolymer has a degree of polymerization in the range of 10 to 200, preferably 20 to 180, more preferably 30 to 150.

21. The composition according to claim 17 or 18, comprising the multi-block copolymer and at least one carboxylate-based anionic surfactant, wherein the cationic block A of the multi-block copolymer has a degree of polymerization in the range of 30 to 500, preferably 60 to 400, more preferably 100 to 300.

22. The composition according to any one of claims 17 to 21 , further comprises at least one co-surfactant.

23. The composition according to any one of claims 17 to 22 further comprises one or more benefit agents of a personal care composition.

24. The composition according to any one of claims 17 to 23, wherein the composition is a rinse-off personal care composition to be used on skin and/or hair.