Multi-stage polymer, its preparation process, composition, and use

Abstract

MULTI-STEP POLYMER, ITS PREPARATION PROCESS, COMPOSITION COMPRISING IT, AND ITS USE. The present invention relates to a composition comprising a multi-step polymer, its preparation process, a composition comprising it, and its use. In particular, the present invention relates to a composition in the form of a polymer powder comprising a relatively simple multi-step polymer in the form of polymeric particles obtained by a multi-step process. More particularly, the present invention relates to a polymer composition in the form of a polymer powder comprising polymeric particles obtained by a multi-step process comprising two steps and comprising an internal (meth)acrylic polymer or copolymer including side ester groups, its preparation process, its use, and compositions and articles comprising it.

Description

Title of the invention: MULTI-STAGE POLYMER, ITS PREPARATION PROCESS, COMPOSITION INCLUDING IT AND ITS USE technical field

[0001] The present invention relates to a composition comprising a multi-step polymer, its preparation process, a composition comprising it and its use.

[0002] In particular, the present invention relates to a composition in the form of a polymer powder comprising a relatively simple multi-step polymer in the form of polymeric particles obtained by a multi-step process.

[0003] More particularly, the present invention relates to a polymer composition in the form of a polymer powder comprising polymer particles obtained by a multi-step process comprising two steps and comprising an internal (meth)acrylic polymer or copolymer comprising ester groups or lateral polyester groups, its preparation process, its use and compositions and articles comprising it. [Technical problem]

[0004] Polymers are also widely used as additives in polymer compositions. These so-called polymer additives are usually added as granules or also as powder, either to solid polymers, molten polymers, liquid resins, or liquid compositions.

[0005] One class of polymeric additives consists of processing auxiliaries, another consists of polymeric shock resistance modifiers.

[0006] Polymeric impact resistance modifiers can be in the form of polymer particle block copolymers, in order to form an elastomeric or rubber phase dispersed in a continuous phase.

[0007] These polymeric impact resistance modifiers in the form of polymer particles are usually in the form of core-shell particles obtained by a multi-step process, at least one step of which includes a rubber-type polymer. These particles are then incorporated into the polymers or polymer compositions to increase their impact resistance. The polymers or polymer compositions may be thermosetting or thermoplastic.

[0008] Thermosetting polymers consist of three-dimensional crosslinked structures. Crosslinking is achieved by hardening reactive groups in the called prepolymer. Hardening, for example, can be achieved by heating the polymer chains or the prepolymer in order to crosslink and permanently harden the material.

[0009] Thermoplastic polymers consist of linear or branched polymers, which are not usually cross-linked. They may be slightly cross-linked as long as they can be deformed by heat. However, these aforementioned core-shell particles are not easily dispersed or disperse rapidly in all kinds of resins or polymers or polymer precursors, particularly, for example, in polyesters.

[0010] Good, homogeneous, and rapid dispersion is necessary to achieve satisfactory impact resistance performance in the final polymer composition. An easy and rapid dispersion process and a fast dispersion time are also required to reduce processing time and optimize the use of a simpler and easier process.

[0011] This applies to virgin polymers as well as recycled polymers. The latter could use a different quantity of impact resistance modifiers to improve properties.

[0012] An objective of the present invention is to propose a polymer composition as an impact resistance modifier that is rapidly and easily dispersible, particularly in thermoplastic polymers such as polyesters, but also in monomers or precursors for polymers such as polyols.

[0013] The present invention also aims to provide a polymer composition as an impact resistance modifier in the form of a polymer powder that is rapidly and easily dispersible, particularly in thermoplastic polymers such as polyesters and blends comprising polyesters.

[0014] An additional objective of the present invention is to provide a polymer composition as an impact resistance modifier in the form of a dry polymer powder, with reduced clumping and good flowability, easily dispersible, particularly in thermoplastic polymers such as polyesters and blends comprising polyesters.

[0015] An objective of the present invention is also to propose a polymer composition as an impact resistance modifier that is easily dispersible and that comprises raw materials less harmful than those of some conventional impact resistance modifiers of today, in particular an impact resistance modifier for thermoplastic polymers, and more particularly for polyesters.

[0016] An additional objective of the present invention is to propose a polymer composition as an impact resistance modifier for polyesters.

[0017] An additional objective of the present invention is to provide a polymer composition as an impact resistance modifier for recycled polyesters, virgin polyesters, blends of recycled polyesters or blends of virgin and recycled polyesters.

[0018] Another objective of the present invention is to propose a simplified method for preparing a polymer composition in the form of a polymer powder that is rapidly and easily dispersible, particularly in thermoplastic polymers such as polyesters.

[0019] Another objective of the present invention is the use of a polymer composition in the form of polymer powder for the preparation of thermoplastic polymers with modified impact resistance.

[0020] Another objective is to offer polymeric articles with modified impact resistance, in particular based on polyesters or polyester blends, including recycled polyesters. [BACKGROUND OF THE INVENTION] Prior art

[0021] Document WO2016 / 102666 discloses a composition comprising a multi-step polymer and its preparation process. The composition further comprises a (meth)acrylic polymer having a mass average molecular weight of less than 100,000 g / mol. The (meth)acrylic polymer may comprise a functional monomeric unit.

[0022] Document WO2016 / 102682 discloses a multi-step polymer composition and its preparation process. The multi-step polymer includes a final step comprising a (meth)acrylic polymer having a mass average molecular weight of less than 100,000 g / mol. The (meth)acrylic polymer may include a functional monomeric unit.

[0023] Document WO2019 / 012052 discloses a composition comprising a multi-step polymer and its preparation process. The composition further comprises a (meth)acrylic polymer having a mass average molecular weight between 100,000 g / mol and 1,000,000 g / mol. The (meth)acrylic polymer may comprise a functional monomeric unit.

[0024] Patent application EP3733727 discloses a grafted polymer containing rubber and a resin composition containing said grafted polymer containing rubber. The grafted polymer containing rubber is grafted with a caprolactone.

[0025] Document EP0362855 discloses a core-shell polymer and compositions comprising it. The core-shell polymer comprises epoxy groups.

[0026] PPE document 104784 discloses thermoplastic polyester compositions having improved impact resistance properties. The impact resistance modifier comprises a core-shell polymer and a functional ethylene copolymer having carboxylic acid anhydride or epoxy groups.

[0027] Document EP1252234 discloses thermoplastic polyester compositions having improved impact resistance properties and an impact resistance modification composition. The impact resistance modification composition comprises a core-shell polymer, a functional ethylene copolymer having carboxylic acid anhydride or epoxy functions, and a copolymer selected from ethylene-(meth)acrylate alkyl copolymers, optionally neutralized ethylene-(meth)acrylic acid copolymers.

[0028] None of the prior art documents disclose a composition comprising a simple impact resistance modifier as a multi-step polymer having a shell over the rubber-like polymer, said shell polymer comprising monomeric motifs having lateral polyester functions. [Brief description of the invention]

[0029] Surprisingly, it was found that a polymer composition (PCI) comprising:

[0030] a) a polymer (Al) having a glass transition temperature below 10 °C,

[0031] b) a polymer (Bl) having a glass transition temperature of at least 60 °C, said polymer (Bl) representing at least 2% by weight and at most 30% by weight of the composition based on a) and b) only,

[0032] component a) and component b) of the composition (PCI) forming part of a multi-step polymer (MPI),

[0033] characterized in that the polymer (Al) comprises between 1% by weight and up to 100% by weight of polymerized monomeric motif (CLM) of general formula CH2=CRi COO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10,

[0034] makes it possible to provide a suitable polymer composition as an impact resistance modifier, which is rapidly, easily and homogeneously dispersible, particularly in thermoplastic polymers such as polyesters, and which exhibits reduced caking and good flowability

[0035] Surprisingly, it was also found that a process for manufacturing the polymer composition (PCI) comprising the steps of:

[0036] a) emulsion polymerization of a monomer or a mixture of monomers (Am) to obtain a layer in a step (A) comprising the polymer (Al) having a glass transition temperature below 10 °C,

[0037] b) emulsion polymerization of a monomer or a mixture of monomers (Bm) to obtain a layer in a step (B) comprising a polymer (Bl) having a glass transition temperature of at least 60 °C, said polymer (Bl) representing at least 2% by weight and at most 30% by weight of the composition based on a) and b) only,

[0038] characterized in that said mixture of monomers (Am) comprises between 1% by weight and up to 100% by weight of a monomeric motif (CLM) of general formula CH2=CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10,

[0039] makes it possible to provide a rapid manufacturing process for a polymer composition suitable as an impact strength modifier, which is rapidly and easily dispersible, in particular in thermoplastic polymers such as, for example, in polyesters, while using raw materials which are less toxic than those of today's conventional impact strength modifiers for polyesters.

[0040] Surprisingly, it was also found that a polymer composition (PC2) comprising:

[0041] a) the polymer composition (PCI) according to the first aspect and

[0042] b) a thermoplastic polymer (TPI)

[0043] produces a polymer composition (PC2) having better impact resistance performance compared to an impact resistance modification composition not comprising a polymerized monomeric motif (CLM).

[0044] Surprisingly, it was also found that a polymer composition (PCI) comprising:

[0045] a) a polymer (Al) having a glass transition temperature below 10 °C,

[0046] b) a polymer (Bl) having a glass transition temperature of at least 60 °C, said polymer (Bl) representing at least 2% by weight and at most 30% by weight of the composition based on a) and b) only,

[0047] component a) and component b) of the composition (PCI) forming part of a multi-step polymer (MPI),

[0048] characterized in that the polymer (Al) comprises between 1 wt% and up to 100 wt% of a polymerized monomeric unit (CLM) of general formula CH2=CRi COO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10,

[0049] can be used as an impact resistance modifier, which is rapidly, easily and homogeneously dispersible, particularly in thermoplastic polymers such as polyesters. Description of the implementation methods

[0050] According to a first aspect, the present invention relates to a polymer composition (PCI) comprising:

[0051] a) a polymer (Al) having a glass transition temperature below 10 °C,

[0052] b) a polymer (Bl) having a glass transition temperature of at least 60 °C, said polymer (Bl) representing at least 2% by weight and at most 40% by weight of the composition based on a) and b) only,

[0053] component a) and component b) of the composition (PCI) forming part of a multi-step polymer (MPI),

[0054] characterized in that the polymer (Al) comprises between 1% by weight and up to 100% by weight of polymerized monomeric motif (CLM) of general formula CH2=CRi COO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10.

[0055] According to a second aspect, the present invention relates to a method for manufacturing the polymer composition (PCI) comprising the steps of:

[0056] a) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Am) to obtain a layer in a step (A) comprising the polymer (Al) having a glass transition temperature below 10 °C,

[0057] b) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Bm) to obtain a layer in a step (B) comprising a polymer (Bl) having a glass transition temperature of at least 60 °C, said polymer (Bl) representing at least 2% by weight and at most 30% by weight of the composition based on a) and b) only,

[0058] characterized in that said mixture of monomers (Am) comprises between 1% by weight and up to 100% by weight of a monomeric motif (CLM) of general formula CH2 =CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10.

[0059] In a third aspect, the present invention relates to a method for manufacturing the polymer composition (PCI) in the form of a polymer powder comprising the steps of:

[0060] a) polymerization by emulsion polymerization of the monomer or mixture of monomers (Am) to obtain a layer in a step (A) comprising the polymer (Al) having a glass transition temperature below 10 °C;

[0061] b) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Bm) to obtain a layer in a step (B) comprising a polymer (Bl) having a glass transition temperature of at least 60 °C;

[0062] c) agglomeration of the composition obtained in steps a) to b);

[0063] characterized in that said mixture of monomers (Am) comprises between 1% by weight and up to 100% by weight of a monomeric motif (CLM) of general formula CH2 =CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10.

[0064] In a fourth aspect, the present invention relates to the use of a polymer composition (PCI) as an impact resistance modifier.

[0065] In a fifth aspect, the present invention relates to the use of a polymer composition (PCI) as a reduced dispersion time composition.

[0066] In a sixth aspect, the present invention relates to a method for reducing the dispersion time of a polymer composition (PCI) in a thermoplastic polymer, preferably a polyester or a polymer blend comprising a polyester, using the polymer composition (PCI) in the form of a polymer powder.

[0067] In a seventh aspect, the present invention relates to a polymer composition (PC2) comprising the polymer composition (PCI) as an impact resistance modifier.

[0068] In an eighth aspect, the present invention relates to a method for reducing the dispersion time of a polymer composition (PCI) in a thermoplastic polymer (TPI) comprising the steps of:

[0069] a) supply of said polymer composition (PCI) of the first aspect in the form of a porous polymer powder (P0W1) having a total penetration volume of at least 0.6 ml / g as measured by mercury porosimetry,

[0070] b) mixing of the polymer composition (PCI) with the thermoplastic polymer (TPI).

[0071] In a ninth aspect, the present invention relates to a polymer composition (PC2) comprising:

[0072] a) a polymer composition (PCI) of the first aspect and

[0073] b) a thermoplastic polymer (TPI), preferably selected from a polyester.

[0074] The expression "polymer powder" as used refers to a polymer in in the form of a powder comprising powder grains of at least 1 µm, said powder grains being obtained by agglomeration of primary polymer particles comprising one or more polymers, said primary polymer particles being on the order of nanometers.

[0075] The term "primary particle" as used herein refers to a spherical polymer particle comprising a particle on the order of a nanometer. Preferably, the primary particle has an average particle size by weight of between 20 nm and 800 nm.

[0076] The expression "particle size" as used refers to the average volume diameter of a particle considered to be spherical.

[0077] The term "thermoplastic polymer" as used herein refers to a polymer which is converted into a liquid or becomes more liquid or less viscous when heated and which can take on new shapes by the application of heat and pressure.

[0078] The expression "thermosetting polymer" as used refers to a prepolymer in a soft, solid or viscous state which is irreversibly transformed into an infusible and insoluble polymer network by hardening.

[0079] The term "copolymer" as used means that the polymer consists of at least two different monomeric units.

[0080] The expression "multi-step polymer" as used herein refers to a polymer formed sequentially by a multi-step polymerization process. Preferably, a multi-step emulsion polymerization process is used in which the first polymer is a first-step polymer and the second polymer is a second-step polymer; that is, the second polymer is formed by emulsion polymerization in the presence of the first polymer in emulsion, with at least two steps that differ in composition.

[0081] The term "(meth)acrylic" as used refers to all kinds of acrylic and methacrylic monomers.

[0082] The expression "(meth)acrylic polymer" as used refers to the fact that the (meth)acrylic polymer essentially comprises polymers comprising (meth)acrylic monomers which represent 50% or more by weight of the (meth)acrylic polymer.

[0083] The term "dry" as used means that the proportion of residual water is less than 1.5% by weight and preferably less than 1.2% by weight.

[0084] By specifying that a range goes from x to y in the present invention, this means that the upper and lower limits of this range are included, which is equivalent to at least x and up to y.

[0085] By specifying that a range is between x and y in the present invention, this means that the upper and lower limits of this range are excluded, which is equivalent to more than x and less than y.

[0086] The term "total penetration volume" as used herein refers to the total volume into which liquid mercury enters, in accordance with ISO 15901-1:2016. This volume is cumulative, and the analysis results show the cumulative penetration volume in ml / g (cm³ / g) as a function of the applied pressure or the pore diameter. The total penetration volume is the penetration volume at the maximum applied pressure, which also corresponds to the smallest pores.

[0087] The term "incremental penetration" as used herein refers to the penetration volume in ml / g between two certain pressures or between two pore dimensions. This incremental penetration can also be expressed relative to the total penetration volume as a percentage by volume.

[0088] By "easily dispersed in liquid resins," it is meant that a homogeneous dispersion is obtained. The distribution of the polymer composition (PCI) is not homogeneous if separation occurs after initial homogenization.

[0089] By "rapidly dispersed", it is meant that a homogeneous dispersion is obtained much more rapidly than with a polymer composition not having the specific composition comprising a polymerized monomeric motif (CLM).

[0090] With regard to the polymer composition (PCI) according to the invention, it can be carried out according to a first embodiment in the form of a polymer powder, also called polymer powder P0W1, comprising a) the polymer (Al) having a glass transition temperature below 10 °C, b) the polymer (Bl) having a glass transition temperature of at least 60 °C, said polymer (Bl) representing at least 2% by weight and at most 40% by weight of the composition based on a) and b) only, component a) and component b) of the composition (PCI) being part of a multi-step polymer (MPI) and the polymer (Al) comprising between 1% by weight and up to 100% by weight of polymerized monomeric unit (CLM) of general formula CH2=CR1COO(CH2)m(OCO(CH2)nl)n2OH, R! being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10.

[0091] Preferably, component b) represents at least 3% by weight of a composition based on a) and b). More preferably, component b) represents at least 4% by weight of the composition based on a) and b), and even more preferably at least 5% by weight

[0092] Preferably, component b) represents at most 40% by weight of a composition based on a) and b). More preferably, component b) represents at most 35% by weight of the composition based on a) and b) and even more preferably at most 30% by weight.

[0093] In a first advantageous embodiment, component b) represents less than 29% by weight of a composition based on a) and b).

[0094] In a second advantageous embodiment, component b) represents less than 28% by weight of a composition based on a) and b).

[0095] In a third advantageous embodiment, component b) represents less than 27% by weight of a composition based on a) and b).

[0096] Preferably, component b) represents more than 5% by weight of a composition based on a) and b). More preferably, component b) represents more than 6% by weight of the composition based on a) and b).

[0097] In a first advantageous embodiment, component b) represents more than 7% by weight of a composition based on a) and b).

[0098] In a second advantageous embodiment, component b) represents more than 8% by weight of a composition based on a) and b).

[0099] In a third advantageous embodiment, component b) represents more than 9% by weight of a composition based on a) and b).

[0100] The respective upper and lower limits given in the preceding paragraphs for the quantity of component b) can be combined in any combinations of an upper limit and a lower limit.

[0101] Preferably, component b) represents between 5% by weight and 30% by weight of the composition based on a) and b). More preferably, component b) represents between 6% by weight and 25% by weight of the composition based on a) and b).

[0102] In a first advantageous embodiment, component b) represents between 6% by weight and 22% by weight of a composition based on a) and b).

[0103] In a second advantageous embodiment, component c) represents between 8% by weight and 20% by weight of a composition based on a) and b).

[0104] In a third advantageous embodiment, component b) represents between 6% by weight and 15% by weight of a composition based on a) and b).

[0105] Component a) and component b) of the composition (PCI) are part of a multi-step polymer (MPI).

[0106] At least component a) and component b) are obtained by a multi-step process comprising at least two steps (A) and (B) respectively; and these two components, polymer (Al) and polymer (Bl), form a multi-step polymer (MPI).

[0107] With regard to the polymer powder (POW1), it has a median volume particle size D50 of between 1 pm and 700 pm. Preferably, the median volume particle size of the polymer powder is between 10 pm and 600 pm, more preferably between 15 pm and 550 pm and advantageously between 20 pm and 500 pm.

[0108] The D10 of the volume particle size distribution is at least 10 pm and preferably 15 pm, more preferably 20 pm.

[0109] The D90 of the volume particle size distribution is at most 1000 pm and preferably 950 pm, more preferably at most 925 pm and even more preferably at most 900 pm.

[0110] In one embodiment, the porosity of the polymer composition (PCI) in the form of a polymer powder (P0W1) is expressed as total penetration volume or cumulative total penetration (cumulative penetration volume) in milliliters (ml) of mercury per mass (g) of said POWL polymer powder. This is measured according to ISO 15901-1: Evaluation of pore size distribution and porosity of solid materials by mercury porosimetry and gas adsorption - Part 1: Mercury porosimetry. Preferably, the polymer powder (P0W1) of the invention has a total penetration volume or cumulative total penetration of at least 0.6 ml / g, preferably 0.65 ml / g, more preferably 0.7 ml / g, and even more preferably 0.75 ml / g. The cumulative total penetration is taken into account down to a pore size diameter of 0.005 µm.Preferably, the total penetration volume or the cumulative total penetration is taken into account for a pore size diameter between 100 pm and 0.005 pm or a pressure between 0.01 MPa and 400 MPa.

[0111] The polymer powder (POW1) of the invention has a total volume of penetration or a total cumulative penetration of at most 10 ml / g. Preferably, the total penetration volume is at most 8 ml / g, more preferably at most 7 ml / g, even more preferably at most 6 ml / g, advantageously at most 5 ml / g, more advantageously at most 4 ml / g and most advantageously at most 3.5 ml / g.

[0112] The respective upper and lower limits given in the two preceding paragraphs for the total penetration volume or the cumulative total penetration of the porous polymer powder (P0W1) of the invention can be combined in any combinations of an upper limit and a lower limit.

[0113] Preferably, the polymer powder (P0W1) of the invention has a total penetration volume or cumulative total penetration of between 0.6 ml / g and 10 ml / g, more preferably between ml / g and 8 ml / g, even more preferably between 0.65 ml / g and 7 ml / g, advantageously between 0.65 ml / g and 6 ml / g, more advantageously between 0.65 ml / g and 5 ml / g, more advantageously between 0.7 ml / g and 4 ml / g and most advantageously between 0.75 ml / g and 3.5 ml / g.

[0114] The bulk apparent density of the polymer powder (P0W1) is less than 0.60 g / cm³. Preferably, the bulk apparent density is less than 0.45 g / cm³, plus preferably less than 0.43 g / cm3, and even more preferably less than 0.41 g / cm3.

[0115] The bulk apparent density of the polymer powder (P0W1) is greater than 0.1 g / cm3. Preferably, the bulk apparent density is greater than 0.11 g / cm3, more preferably greater than 0.12 g / cm3, and even more preferably greater than 0.13 g / cm3.

[0116] The bulk apparent density of the polymer powder (POW1) is between 0.1 g / cm³ and 0.60 g / cm³. Preferably, the bulk apparent density of the polymer powder (POW1) is between 0.15 g / cm³ and 0.45 g / cm³. Advantageously, the bulk apparent density of the polymer powder (POW1) is between 0.2 g / cm³ and 0.4 g / cm³.

[0117] The respective preferred embodiment of all the different characteristics of the porous polymer powder (P0W1) can be combined in any combination.

[0118] With regard to the polymer composition (PCI) according to the invention, it may, according to a second embodiment, be dispersed in a continuous phase comprising a) the polymer (Al) having a glass transition temperature below 10 °C, b) the polymer (Bl) having a glass transition temperature of at least 60 °C, components a) and b) of the composition (PCI) being part of a multi-step polymer (MPI) and the polymer (Bl) comprising between 1 wt% and up to 100 wt% of a polymerized monomeric unit (CLM), and c) a thermoplastic polymer (TPI). The thermoplastic polymer (TPI) may be a continuous phase in which the polymer composition (PCI) is dispersed.

[0119] The multi-step polymer (MPI) of composition (PCl) according to the invention comprises at least two steps (A) and (B) respectively; and these two steps, comprising respectively polymer (Al) and polymer (Bl), are different in their polymer composition.

[0120] The multi-step polymer (MSP) is preferably in the form of polymer particles (PP). These particles (PP) are also called core-shell particles. For example, the first step comprising the polymer (Al) forms the core, and the second or all subsequent steps form the respective shells. Such a multi-step polymer (MSP), which is also called a core-shell particle, is preferred. If the multi-step polymer (MSP) comprises only the polymer (Al) and the polymer (Bl), it is a core-shell particle comprising only a shell.

[0121] In a first preferred embodiment, the multi-step polymer (MPI) of the composition (PCI) consists of the polymer (Al) forming the core and of the polymer (Bl) forming the envelope; it is a core-envelope particle comprising only an envelope.

[0122] In a second preferred embodiment, the multi-step polymer (MPI) of the composition (PCI) consists of a seed and the polymer (Al), together forming the core, and the polymer (Bl) forming the shell; it is also considered to be a core-shell particle comprising only a shell.

[0123] In a third preferred embodiment, the multi-step polymer (MPI) consists of the polymer (Al) forming the core or an inner step or shell and the polymer (Bl) forming the shell covering the polymer (Al) or formed subsequently; it is a core-shell particle potentially having several shells.

[0124] In a fourth preferred embodiment, the multi-step polymer (MPI) of the composition (PCI) consists of the polymer (Al) forming the core or an inner step or shell, the polymer (Bl) forming a shell covering the polymer (Al) and the polymer (Cl) forming a shell covering the polymer (Bl), the polymer (Cl) being the outer shell.

[0125] The particles (PAR), included in the polymer composition (PCI) in the form of polymer powder (POW1) according to one embodiment or dispersed according to another embodiment, are the primary particles.

[0126] The particles (PAR) have an average particle size by weight of between 15 nm and 900 nm. Preferably, the average particle size by weight of the polymer particle is between 20 nm and 800 nm, more preferably between 25 nm and 600 nm, even more preferably between 30 nm and 550 nm, even more preferably between 35 nm and 500 nm, advantageously between 40 nm and 400 nm, even more advantageously between 75 nm and 350 nm, and advantageously between 80 nm and 300 nm.

[0127] According to a first preferred embodiment, the primary polymer particles (PAR) are agglomerated and give the polymer composition (PCI) or a part of the polymer composition (PCI). In this case, the polymer composition (PCI) of the invention is in the form of a polymer powder, as described above.

[0128] The polymer composition (PCI) according to the invention comprises a multi-step polymer (MPI) comprising at least a) a step (A) comprising a polymer (Al) having a glass transition temperature below 10 °C and at least b) a step (B) comprising a polymer (Bl) having a glass transition temperature above 60 °C.

[0129] In a first preferred embodiment, step (A) is the first step of said at least two steps and step (B) comprising polymer (Bl) covers step (A) comprising polymer (Al).

[0130] In a second preferred embodiment, a seed could also be added before step (A), so that step (A) and the seed together would be considered as a first step, and step (B) comprising the polymer (Bl) covers step (A) comprising the seed and the polymer (Al).

[0131] In a third preferred embodiment, step (A) is the first of the two steps, step (B) comprising polymer (Bl) covers step (A) comprising polymer (Al), and the multi-step polymer (MPI) consists of step (A) comprising polymer (Al) and step (B) comprising polymer (Bl).

[0132] Step (B) takes place after step (A). More preferably, step (B) is the last step and polymer (Bl) is the outer shell of the multi-step polymer (MPI).

[0133] With regard to the polymerized monomeric motif (CLM) of general formula CH2=CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10, it is part of the polymer (Al) from 1% by weight up to 100% by weight.

[0134] The polymer (Al) is a homopolymer or a copolymer, comprising a polymerized monomeric motif (CLM).

[0135] The monomeric motif (CLM) has the general formula CH2=CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10.

[0136] Preferably, m is an integer from 1 to 4. In one embodiment, m = 2, and in another embodiment, m = 4. In a first preferred embodiment, m = 2.

[0137] Preferably, ni is an integer from 2 to 8, more preferably from 3 to 8. In one embodiment, ni = 5. In another embodiment, ni = 4. In yet another embodiment, ni = 3.

[0138] In a first preferred embodiment, ni = 5.

[0139] Preferably, n2 is an integer from 1 to 8, more preferably from 1 to 6. In one embodiment, n2 is from 1 to 5.

[0140] In a first preferred embodiment, the monomeric motif (CLM) is represented by the formula (1)

[0141] [Formula 1]

[0142] in which Ri is H or CH3 and n2 is from 1 to 5.

[0143] In a second preferred embodiment, the monomeric motif (CLM) is represented by the formula (2)

[0144] [Formula 2] B'!

[0145] in which Ri is H or CH3 and n2 is from 3 to 5.

[0146] In a third preferred embodiment, the monomeric motif (CLM) is of formula (1) in which Ri is H, the polymerizable group being chosen from an acrylate.

[0147] In a fourth preferred embodiment, the monomeric motif (CLM) is of formula (1) in which Ri is CH3, the polymerizable group being chosen from a methacrylate.

[0148] The polymer (Al) comprises from 2 wt% to 100 wt% of polymerized monomeric motif (CLM).

[0149] In a first embodiment, the polymer (Al) having a glass transition temperature below 10 °C comprises at least 50% by weight of polymeric units from an alkyl acrylate or alkyl acrylates, and step (A) is the innermost layer of the polymer particle possessing the multilayer structure. In other words, step (A) comprising the polymer (Al) is the core of the polymer particle.

[0150] In a second embodiment, the polymer (Al) having a glass transition temperature below 10 °C comprises at least 50% by weight of polymeric units derived from alkyl acrylate or alkyl acrylates, and step (A) is an inner layer of the polymer particle having the multilayer structure. In other words, step (A) comprising the polymer (Al) is not the outer layer and is considered to be part of the core of the polymer particle, particularly in the case where a seed is used in the process.

[0151] With regard to the polymer (Al) of the first and second embodiments just mentioned, it is a (meth)acrylic polymer comprising at least 50% by weight of polymeric units derived from (meth)acrylic monomers, including the monomeric unit (CLM). Preferably, 60% by weight and more preferably 70% by weight of the polymer (Al) are (meth)acrylic monomers.

[0152] In a first preferred embodiment, the polymer (Al) comprises at least 80% by weight of polymeric motifs derived from (meth)acrylic monomers, including the monomeric motif (CLM).

[0153] In a second preferred embodiment, the polymer (Al) comprises at least 90% by weight of polymeric motifs derived from (meth) acrylic monomers, including the monomeric motif (CLM).

[0154] In a third preferred embodiment, the polymer (Al) comprises from 80% by weight to 100% by weight of polymeric motifs derived from (meth)acrylic monomers, including the monomeric motif (CLM).

[0155] The acrylic monomer in the polymer (Al) may comprise, in addition to the monomeric unit (CLM), monomers selected from C18 to C1 alkyl acrylates or mixtures thereof. Preferably, the acrylic monomer in the polymer (Al) may comprise, in addition to the monomeric unit (CLM), C2 to C12 alkyl acrylic monomers or mixtures thereof. Preferably still, the acrylic monomer in the polymer (Al) may comprise, in addition to the monomeric unit (CLM), C2 to C8 alkyl acrylic monomers or mixtures thereof.

[0156] The polymer (Al) comprises as a comonomer the monomeric motif (CLM) copolymerizable with the acrylic monomer(s), as long as the polymer (Al) has a glass transition temperature below 10 °C.

[0157] Preferably, the other acrylic or methacrylic comonomers besides the monomeric motif (CLM) of the polymer (Al) are chosen from methyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, tert-butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and mixtures thereof, as long as the polymer (Al) has a glass transition temperature below 10 °C.

[0158] Preferably, the polymer (Al) comprises between 2% by weight and 70% by weight of polymerized monomeric motif (CLM) and, more preferably, between 3% by weight and 50% by weight.

[0159] In one embodiment, the polymer (Al) comprises from 5 wt% to 20 wt% of polymerized monomeric motif (CLM).

[0160] In another embodiment, the polymer (Al) comprises from 5 wt% to 25 wt% of polymerized monomeric motif (CLM).

[0161] In another embodiment, the polymer (Al) comprises from 10 wt% to 50 wt% of polymerized monomeric motif (CLM).

[0162] In another embodiment, the polymer (Al) comprises from 10 wt% to 40 wt% of polymerized monomeric motif (CLM).

[0163] The polymer (Al) may include a crosslinking agent or a grafted crosslinking agent.

[0164] In a specific embodiment, the polymer (Al) is a copolymer comprising butyl acrylate and a monomeric motif (CLM).

[0165] In another specific embodiment, the polymer (Al) is a butyl acrylate copolymer, monomeric motif (CLM) and another preferred acrylic or methacrylic comonomer.

[0166] In yet another specific embodiment, the polymer (Al) is a copolymer of butyl acrylate, monomeric motif (CLM) and allyl methacrylate.

[0167] More preferably, the glass transition temperature Tg of the polymer (Al) comprising at least 70% by weight of polymeric motifs from the monomeric motif (CLM) and a C2 to C8 alkyl acrylate is between -100 °C and 10 °C, even more preferably between -80 °C and 0 °C, advantageously between -80 °C and -20 °C and more advantageously between -70 °C and -20 °C.

[0168] The polymer (Al) having a glass transition temperature below 10 °C comprises monomeric units, which have been polymerized. The polymer (Al) in general and the respective polymers (Al) of the first preferred embodiment are prepared from the respective mixture of monomers (Am) giving, after polymerization, the polymer (Al) composed of the monomeric units.

[0169] With regard to the polymer (Bl), examples include homopolymers and copolymers comprising monomers with double bonds and / or vinyls. Preferably, the polymer (Bl) is a (meth)acrylic polymer.

[0170] Preferably, the polymer (Bl) is a (meth)acrylic polymer, meaning that at least 50% by weight of the monomeric motifs of the polymer (Bl) are (meth)acrylic monomers.

[0171] Preferably, the polymer (Bl) comprises at least 70% by weight of monomers selected from C12 alkyl Cl (meth)acrylates. Even more preferably, the polymer (Bl) comprises at least 80% by weight of monomers selected from C4 alkyl Cl methacrylate and / or C8 alkyl Cl acrylate monomers. Still more preferably, the polymer (Bl) comprises at least 80% by weight of monomers selected from C4 alkyl Cl methacrylate and C8 alkyl Cl acrylate monomers.

[0172] Most preferably, the acrylic or methacrylic monomers of the polymer (Bl) are chosen from methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and corresponding mixtures, as long as the polymer (Bl) has a glass transition temperature of at least 60 °C.

[0173] Advantageously, the polymer (Bl) comprises at least 30% by weight of monomeric motifs derived from methyl methacrylate.

[0174] In a first advantageous embodiment, the polymer (B 1) comprises at least 70% by weight of monomeric motifs from methyl methacrylate.

[0175] In a second advantageous embodiment, the polymer (Bl) comprises at least 80% by weight of monomeric motifs from methyl methacrylate.

[0176] In a third advantageous embodiment, the polymer (Bl) comprises from 70 wt% to 100 wt% of monomeric motifs from methyl methacrylate.

[0177] In a fourth advantageous embodiment, the polymer (Bl) comprises at least 50% by weight of monomeric motifs from methyl methacrylate.

[0178] In a fifth advantageous embodiment, the polymer (Bl) comprises from 50 wt% to 100 wt% of monomeric motifs from methyl methacrylate.

[0179] Alternatively, the polymer (Bl) may be a copolymer. In this case, the respective monomers are derived from a mixture of monomers (Bm) comprising at least two monomers from the preferred list.

[0180] Preferably, the glass transition temperature Tg of the polymer (Bl) is between 60 °C and 150 °C. The glass transition temperature of the polymer (Bl) is more preferably between 70 °C and 140 °C, advantageously between 80 °C and 130 °C and more advantageously between 85 °C and 125 °C.

[0181] Preferably, a portion of the polymer (Bl) is grafted onto the polymer prepared in the previous step.

[0182] Preferably, the polymer (B1) is not fully grafted. By "not fully grafted," it is meant that at least 5% by weight of the polymer (B1) in the multi-step polymer (MPI) can be solubilized in a solvent of the polymer (B1) and extracted. Preferably, at least 10% by weight of the copolymer (B1) in the multi-step polymer (MPI) can be solubilized in a solvent of the copolymer (B1) and extracted.

[0183] The polymer (Bl) having a glass transition temperature of at least 60 °C comprises polymerized monomeric units. The polymer (Bl), in general and in the respective embodiments, is prepared from the respective monomer or monomer mixtures (Bm), giving, after polymerization, the polymer (Bl) comprising polymerized monomeric units included in the copolymer (Bl).

[0184] With regard to the polymer (Bl) or more specifically the extractable part of the polymer (Bl), it can have a mass average molecular weight Mw between 10,000 g / mol and 500,000 g / mol.

[0185] The polymer (Bl) may have a mass average molecular weight Mw greater than 10,000 g / mol, preferably greater than 10,500 g / mol, even more preferably greater than 11,000 g / mol, even more preferably greater than 12,000 g / mol mole, advantageously greater than 13,000 g / mole, more advantageously greater than 14,000 g / mole and even more advantageously greater than 15,000 g / mole.

[0186] The polymer (Bl) or more specifically the extractable part of the polymer (Bl) may have a mass average molecular weight Mw of less than 500,000 g / mol, preferably less than 450,000 g / mol, more preferably less than 400,000 g / mol, even more preferably less than 400,000 g / mol, advantageously less than 350,000 g / mol, more advantageously less than 300,000 g / mol, even more advantageously less than 250,000 g / mol and most advantageously less than 200,000 g / mol.

[0187] Preferably, the average molecular weight by mass Mw of the polymer (Bl) or more specifically of the extractable part of the polymer (Bl) can be between 10,500 g / mol and 450,000 g / mol, more preferably between 11,000 g / mol and 400,000 g / mol, even more preferably between 12,000 g / mol and 350,000 g / mol, advantageously between 13,000 g / mol and 300,000 g / mol, more advantageously between 14,000 g / mol and 250,000 g / mol and most advantageously between 15,000 g / mol and 200,000 g / mol.

[0188] In a first advantageous embodiment, the average molecular weight by mass Mw of the (meth)acrylic polymer (Bl) or more specifically of the extractable part of the polymer (Bl) can be between 10,500 g / mol and 200,000 g / mol, more preferably between 11,000 g / mol and 190,000 g / mol, even more preferably between 12,000 g / mol and 180,000 g / mol, advantageously between 13,000 g / mol and 150,000 g / mol, more advantageously between 14,000 g / mol and 135,000 g / mol and most advantageously between 15,000 g / mol and 120,000 g / mol.

[0189] In a second advantageous embodiment, the average molecular weight by mass Mw of the (meth)acrylic polymer (Bl) or more specifically of the extractable part of the polymer (Bl) can be between 15,000 g / mol and 450,000 g / mol, more preferably between 15,500 g / mol and 400,000 g / mol, even more preferably between 16,000 g / mol and 350,000 g / mol, advantageously between 16,500 g / mol and 300,000 g / mol, more advantageously between 17,000 g / mol and 250,000 g / mol and most advantageously between 17,500 g / mol and 200,000 g / mol.

[0190] The respective preferred and advantageous embodiments of all the different characteristics of the polymers (Al) and (B 1) and of their respective monomers can be combined in any combination.

[0191] The multi-step polymer (MPI) is obtained by a multi-step process comprising at least two steps. Component a) and component b) of the composition (PCI) are part of a multi-step polymer (MPI).

[0192] Preferably, the polymer (Al) having a glass transition temperature below 10 °C prepared during step (A) is prepared before step (B) or is the first step of the multi-step process.

[0193] The copolymer (Bl) having a glass transition temperature of at least 60 °C prepared during step (B) is prepared after step (A) of the multi-step process.

[0194] More preferably, the copolymer (Bl) having a glass transition temperature of at least 60 °C prepared during step (B) is the outer layer of the multi-step polymer (MPI).

[0195] Additional intermediate steps could exist between step (A) and step (B).

[0196] The weight ratio r of the copolymer (B 1) of the outer layer included in step (B) with respect to the whole polymer particle or the multi-step polymer (MPI) is at least 2% by weight, preferably at least 5% by weight and even better at least 8% by weight.

[0197] According to the invention, the ratio r of the outer step (B) comprising the copolymer (B 1) with respect to the complete polymer particle or the multi-step polymer (MPI) is at most 40% by weight.

[0198] Preferably, the ratio of the polymer (B 1) to the polymer particle or multi-step polymer (MPI) is between 2% by weight and 30% by weight and preferably between 5% by weight and 25% by weight.

[0199] In a preferred embodiment, the polymer (Bl) having a glass transition temperature of at least 60 °C is the outer layer of the primary polymer particle having the multilayer structure, i.e. the multi-step polymer (MPI).

[0200] Preferably, at least a portion of the copolymer (Bl) from layer (B) is grafted onto the polymer prepared in the preceding layer. If only two steps (A) and (B) comprising polymers (Al) and (B1) respectively are present, a portion of the copolymer (Bl) is grafted onto polymer (Al). More preferably, at least 25% by weight of polymer (Bl) is grafted. The grafting rate can be determined by solvent extraction of the copolymer (Bl) and gravimetric measurement before and after extraction to determine the ungrafted amount.

[0201] In a first preferred embodiment, at least 30% by weight of the polymer (Bl) are grafted.

[0202] In a second, more preferred embodiment, at least 40% by weight of the polymer (Bl) are grafted.

[0203] In a third, more preferred embodiment, at least 50% by weight of the polymer (Bl) are grafted.

[0204] Preferably, at least a portion of the copolymer (Bl) of layer (B) is extractable. More preferably, at least 30% by weight of the polymer (Bl) is extractable.

[0205] In a first preferred embodiment, at least 5% by weight of the polymer (Bl) are extractable.

[0206] In a second, more preferred embodiment, at least 10% by weight of the polymer (Bl) are extractable.

[0207] In a third, more preferred embodiment, at least 15% by weight of the polymer (Bl) are extractable.

[0208] The glass transition temperature Tg of the respective polymers can be estimated, for example, by dynamic processes such as thermomechanical analysis.

[0209] In order to obtain a sample of the respective polymers (Al) and (Bl), these can be prepared individually, rather than by a multi-step process, to more easily estimate and measure the individual glass transition temperature Tg of the respective polymers in the respective steps. The copolymer (Bl) can be extracted to estimate and measure the glass transition temperature Tg and / or the molecular weight.

[0210] Preferably, the polymer composition of the invention, if in powder form, does not contain solvents. “No solvents” means that any solvent present represents less than 1% by weight of the composition. Monomers from the synthesis of the respective polymers are not considered solvents. Residual monomers in the composition represent less than 2% by weight of the composition.

[0211] Preferably, the polymer composition according to the invention, if in powder form, is dry. “Dry” means that the polymer composition according to the present invention comprises less than 3% by weight of moisture, preferably less than 1.5% by weight of moisture and more preferably less than 1.2% by weight of moisture.

[0212] Humidity can be measured by a thermobalance which heats the polymer composition and measures the weight loss.

[0213] The composition according to the invention in powder form does not include any intentionally added solvent. Any residual monomers from the polymerization of the respective monomers and water are not considered solvents.

[0214] With regard to a first preferred method of manufacturing the polymer composition (PCI) according to the invention, it comprises the steps of

[0215] A) polymerization by emulsion polymerization of a mixture of monomers (Am) to obtain a layer in step (A) comprising the polymer (Al) having a glass transition temperature below 10 °C;

[0216] b) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Bm) to obtain a layer in a step (B) comprising a polymer (Bl) having a glass transition temperature of at least 60 °C.

[0217] Preferably, step a) is carried out before step b).

[0218] More preferably, step b) is carried out in the presence of the polymer (Al) obtained in step a).

[0219] With regard to a second preferred method of manufacturing the polymer composition (PCI) according to the invention in the form of a polymer powder, it comprises the steps of

[0220] a) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Am) to obtain a layer in a step (A) comprising a polymer (Al) having a glass transition temperature below 10 °C, said mixture of monomers (Am) comprising a monomeric motif (CLM) of general formula CH2=CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10;

[0221] b) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Bm) to obtain a layer in a step (B) comprising a polymer (Bl) having a glass transition temperature of at least 60 °C;

[0222] c) agglomeration of the composition obtained in steps a) to c).

[0223] Preferably, step a) is carried out before step b) and step b) is carried out before step c).

[0224] More preferably, step b) is carried out in the presence of the polymer (Al) obtained in step a).

[0225] Preferably, in step b), no chain transfer agent, in particular mercaptan-based, is used.

[0226] As regards a third preferred method of manufacturing the polymer composition (PCI) according to the invention in the form of a polymer powder, it comprises the steps of

[0227] a) supply or preparation of a germ;

[0228] b) polymerization by emulsion polymerization of a monomer or a mixture of monomers (AM) to obtain a layer in step (A) comprising a polymer (Al) having a glass transition temperature below 10 °C, said mixture of monomers (Am) comprising a monomeric motif (CLM) of general formula CH2=CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10;

[0229] c) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Bm) to obtain a layer in step (B) comprising a polymer (Bl) having a glass transition temperature of at least 60 °C;

[0230] d) agglomeration of the composition obtained in steps a) to c).

[0231] Preferably, step a) is carried out before step b), step b) before step c) and step c) before step d).

[0232] More preferably, step b) is carried out in the presence of the polymer (Al) obtained in step a).

[0233] Advantageously, the first preferred method for manufacturing the polymer composition (PCI) according to the invention is a multi-step process comprising the successive steps of:

[0234] a) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Am) to obtain a layer in a step (A) comprising a polymer (Al) having a glass transition temperature below 10 °C, said mixture of monomers (Am) comprising a monomeric motif (CLM) of general formula CH2=CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10,

[0235] b) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Bm) to obtain a layer in a step (B) comprising a polymer (Bl) having a glass transition temperature of at least 60 °C;

[0236] c) agglomeration of the composition obtained in steps a) to b).

[0237] Preferably, steps a), b) and c) are carried out in that order. When emulsion polymerization is used, the polymer composition at the end of polymerization is obtained as an aqueous dispersion.

[0238] Preferably, in step b), no chain transfer agent, in particular mercaptan-based, is used.

[0239] Advantageously, the second preferred method for manufacturing the polymer composition (PCI) according to the invention is a multi-step process comprising the successive steps of:

[0240] a) supply or preparation of a germ;

[0241] b) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Am) to obtain a layer in step (A) comprising a polymer (Al) having a glass transition temperature below 10 °C, said mixture of monomers (Am) comprising a monomeric motif (CLM) of general formula CH2 =CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10;

[0242] c) polymerization by emulsion polymerization of a monomer or a mixture of monomers (Bm) to obtain a layer in step (B) comprising a polymer (Bl) having a glass transition temperature of at least 60 °C;

[0243] d) agglomeration of the composition obtained in steps a) to c).

[0244] The respective monomers or monomer mixtures (Am) and (Bm) for forming the layers in steps (A) and (B), comprising the polymers (Al) and (Bl) respectively, of preferred and advantageous processes, are the same as defined previously. The monomers or monomer mixtures (Am) and (Bm) comprise the respective monomers that are like polymerized monomeric motifs in the polymer chain of the respective polymers (Al) and (Bl). The characteristics of the polymers (Al) and (Cl), respectively, are the same as those defined previously.

[0245] Preferred and advantageous processes for manufacturing the polymer composition (PCI) comprising the multi-step polymer (MPI) yield the POW1 polymer powder. The POW1 polymer powder is in the form of grains (large particles). The polymer powder grain or particle comprises agglomerated primary polymer particles prepared by a multi-step process comprising the multi-step polymer (MPI) or agglomerated primary polymer particles comprising the multi-step polymer (MPI).

[0246] The agglomeration step can be carried out by coagulation or by flash drying.

[0247] For preferred processes, flash drying is preferred in the agglomeration step.

[0248] The process for manufacturing the polymer composition (PCI) according to the invention may optionally include the additional step d) of drying the polymer composition.

[0249] Preferably after the drying step d), the polymer composition comprises less than 3% by weight, preferably less than 1.5% by weight, advantageously less than 1.2% by weight of moisture or water.

[0250] The moisture content of a polymer composition can be measured with a thermobalance.

[0251] The polymer can be dried for example in an oven or a vacuum oven with heating of the composition for 48 hours at 50 °C.

[0252] Another aspect of the present invention relates to the use of the polymer composition (PCI) as an impact resistance modifier.

[0253] Preferably, the use of polymer composition (PCI) as an impact strength modifier is for a thermoplastic polymer (TPI).

[0254] Another additional aspect of the present invention relates to a polymer composition (PC2) comprising the polymer composition (PCI). Preferably, the thermoplastic polymer composition (PC2) comprises a thermoplastic polymer (TPI).

[0255] The thermoplastic polymer (TPI) can be selected from poly(vinyl chloride) (PVC), chlorinated poly(vinyl chloride) (C-PVC), polyesters such as, for example, poly(ethylene terephthalate) (PET) or poly(butylene terephthalate) (PBT), polyhydroxyalkanoates (PHA) or poly(lactic acid) (PLA), cellulose acetate, polycarbonates (PC), poly(methyl methacrylate) (PMMA), (meth)acrylic copolymers, thermoplastic poly(methyl methacrylate-ethyl coacrylates), poly(alkylene terephthalates), poly(vinylidene fluoride), poly(vinylidene chloride), polyoxymethylene (POM), semi-crystalline polyamides, amorphous polyamides, semi-crystalline copolyamides, amorphous copolyamides, polyetheramides, polyesteramides, styrene-acrylonitrile copolymers (SAN), and their respective mixtures or alloys

[0256] In a first preferred embodiment, the thermoplastic polymer (TPI) is chosen from polyesters, polyester blends or blends comprising polyesters.

[0257] In another preferred embodiment, the polyester is a poly(ethylene terephthalate).

[0258] In another preferred embodiment, the polyester is a poly(butylene terephthalate).

[0259] In yet another preferred embodiment, polyester is a poly(lactic acid).

[0260] In yet another preferred embodiment, polyester is a polyhydroxyalkanoate.

[0261] According to yet another preferred embodiment, the polyester is an alloy comprising at least one polyester selected from poly(ethylene terephthalate), poly(butylene terephthalate), poly(lactic acid) and polyhydroxyalkanoate.

[0262] In one embodiment, the polymer composition (PC2) comprises:

[0263] a) the polymer composition (PCI and

[0264] b) a thermoplastic polymer (TPI)

[0265] the weight ratio of the polymer composition (PCI) to a thermoplastic polymer (TPI) in the polymer composition (PC2) being between 1 / 99 and 99 / 1 or between 2 / 99 and 80 / 20.

[0266] Preferably, the weight ratio of the polymer composition (PCI) to a thermoplastic polymer (TPI) in the polymer composition (PC2) is between 2 / 99 and 80 / 20.

[0267] In a first preferred embodiment, the weight ratio of the polymer composition (PCI) to a thermoplastic polymer (TPI) in the polymer composition (PC2) is between 3 / 97 and 75 / 25.

[0268] In a second preferred embodiment, the weight ratio of the polymer composition (PCI) to a thermoplastic polymer (TPI) in the polymer composition (PC2) is between 4 / 96 and 25 / 75.

[0269] In a third preferred embodiment, the weight ratio of the polymer composition (PCI) to a thermoplastic polymer (TPI) in the polymer composition (PC2) is between 5 / 95 and 50 / 50.

[0270] In a fourth preferred embodiment, the weight ratio of the polymer composition (PCI) to a thermoplastic polymer (TPI) in the polymer composition (PC2) is between 50 / 50 and 80 / 20.

[0271] The polymer composition (PC2) can be injection molded or extruded.

[0272] The polymer composition (PC2) can also be mixed with other polymers, preferably thermoplastic polymers.

[0273] When the weight ratio of the polymer composition (PCI) to a thermoplastic polymer (TPI) in the polymer composition (PC2) is high, the polymer composition (PC2) can be used as a masterbatch. "High" means a weight ratio of the polymer composition (PCI) to a thermoplastic polymer (TPI) greater than 50 / 50.

[0274] The present invention also relates to the use of the polymer composition (PCI) in the form of the polymer powder according to the invention as an impact resistance modifier in polymers, in order to obtain a polymer composition with modified impact resistance. Preferably, the polymers are thermoplastic polymers.

[0275] The present invention also relates to the use of the polymer composition (PC2) in the field of compositions intended for food, packaging, electrical and electronic, automotive, textile, 3D printing and toy applications.

[0276] The present invention also relates to an article comprising the polymer composition (PCI) or the polymer composition (PC2).

[0277] The article may be a bottle, a container, a 3D printed object, a film, a fiber or a textile fiber. [Evaluation methods]

[0278] Glass transition temperature

[0279] The glass transitions (Tg) of polymers are measured using equipment that allows for thermomechanical analysis. A Rheometrics Dynamic Analyzer (RDAII) from Rheometrics Company was used. Thermomechanical analysis accurately measures the viscoelastic changes of a sample as a function of temperature, stress, or applied strain. The device continuously records the strain of the sample, while maintaining a constant stress, during a controlled temperature variation program.

[0280] The results are obtained by graphically representing the modulus of elasticity (G'), the loss modulus, and the loss angle as a function of temperature. Tg is the highest temperature value read from the loss angle curve when the derivative of the loss angle is equal to zero.

[0281] Molecular weight

[0282] The mass average molecular weight (Mw) of the polymers is measured by size exclusion chromatography (SEC). Polystyrene references are used for calibration. The polymer is dissolved in THF at a concentration of 1 g / L. The chromatography column uses modified silica. The flow rate is 1 mL / minute, and a detector for the refractive index is used.

[0283] Extraction

[0284] The extractable portion of the polymer composition is measured by gravimetry. The sample is treated under stirring for 4 hours at 20 °C in 10 g / L THF. The solution is filtered, and after evaporation of the solvent from the filtered solution, the recovered polymer is weighed and its ratio is calculated.

[0285] Particle size analysis

[0286] The particle size of the primary particles after multi-step polymerization is measured with a Malvern Zetasizer using dynamic light scattering. The volume-average particle size (diameter) is taken as the result.

[0287] The particle size of the polymer powder after recovery is measured with a Malvern Mastersizer 3000 from MALVERN with laser diffraction.

[0288] For estimating the average powder particle size by volume, the particle size distribution and the proportion of fine particles, a Malvern Mastersizer 3000 device with 300 mm lenses is used, measuring a range from 0.5 to 880 pm.

[0289] Apparent density

[0290] ISO 60:1977 is used. The sample is purified through a specified funnel into a measuring cylinder with a capacity of 100 cubic centimeters, the excess is removed with a measuring ruler and the mass of the contents is determined by weighing.

[0291] Impact resistance

[0292] ISO 179 type leA is applied.

[0293] [Examples]

[0294] A polymer composition (PCI) in the form of a multi-step core-shell polymer comprising a core and a shell layer is prepared according to the process described.

[0295] ALMA - allyl methacrylate

[0296] BA - butyl acrylate

[0297] MM A - methyl methacrylate

[0298] CLA - caprolactone acrylate

[0299] CLM - caprolactone methacrylate

[0300] As example 1, the following product is prepared:

[0301] First step of core preparation comprising the polymer (Al). In a 20-liter reactor with a stirrer, the following was loaded: 2931 g of deionized water and 18.9 g of sodium hydrogen phosphate. The reactor was rinsed three times under vacuum and filled with nitrogen. The solution was heated to 80 °C with stirring at 150 rpm. A preemulsion of 458.54 g of butyl acrylate, 3.47 g of allyl methacrylate, 18.6 g of sodium dodecylbenzenesulfonate (30 wt% in water), and 320 g of deionized water was introduced into the reactor. Solutions of 2.31 g of potassium persulfate in 37.7 g of water and 1.62 g of sodium metabisulfite in 14.58 g of water were injected into the reactor. The reactor temperature is maintained at 80°C for 30 minutes.A preemulsion of 5093.66 g of butyl acrylate, 700.56 g of caprolactone acrylate, 43.79 g of allyl methacrylate, 235.01 g of sodium dodecylbenzenesulfonate (30 wt% in water), and 2271.1 g of deionized water is introduced into the reactor over 210 minutes. Simultaneously, a solution of 8.76 g of potassium persulfate in 487.7 g of water is also introduced into the reactor over 210 minutes. After the parallel introduction of the preemulsion and the solution, stirring is continued for 80 minutes at 80 °C.

[0302] Second step of preparing the casing comprising the polymer (B 1). The temperature is then maintained at 80 °C, but the stirring speed is increased to 160 rpm. A solution of 1.24 g of sodium formaldehyde sulfoxylate in 38.76 g of water is added to the reactor, along with an emulsion of 689 g of methyl methacrylate, 27.74 g of sodium dodecylbenzenesulfonate, and 206.2 g of water, as well as a solution of 3.44 g of potassium persulfate in 116.6 g of water, for 30 minutes at 80 °C. Next, 1.31 g of sodium metabisulfite in 31.78 g of water is injected into the reactor. The temperature is maintained at 80 °C for 30 minutes. The reactor is then cooled to room temperature. The final conversion rate is 99%. The product, a core-shell particle, is recovered with a flash dryer.

[0303] In examples 2 and 3, the synthesis of example 1 is repeated, only the quantity of caprolactone acrylate is adapted in the first step, to arrive at the quantities indicated in table 1.

[0304] In example 4, we repeat the synthesis of example 1, we reduce the quantity of the outer envelope in the second step, to arrive at the ratio as indicated in table 1.

[0305] In example 5, the synthesis of example 1 is repeated, only caprolactone acrylate is replaced by caprolactone methacrylate in the first step, to arrive at the quantities indicated in Table 1.

[0306] In comparative example 1, the synthesis of example 1 is repeated, only caprolactone acrylate is not used in the first step and is replaced by butyl acrylate.

[0307] In comparative example 2, the synthesis of example 1 is repeated, only caprolactone acrylate is not used in the first step and is replaced by butyl acrylate, but in the second step, 206.7 g of methyl methacrylate are replaced by caprolactone acrylate.

[0308] In comparative example 3, the synthesis of example 1 is repeated, only caprolactone acrylate is not used in the first step and is replaced by butyl acrylate, but in the second step, 137.8 g of methyl methacrylate are replaced by caprolactone acrylate.

[0309] In comparative example 4, the synthesis of example 1 is repeated, only caprolactone acrylate is not used in the first step and is replaced by butyl acrylate, but in the second step, 137.8 g of methyl methacrylate are replaced by caprolactone methacrylate.

[0310] The respective overall compositions of examples 1 to 4 and comparative examples 1 to 4 are summarized in Table 1 with other characteristics.

[0311]

[0312] [Table 1]

[0313] Table 1 - Characteristics Reference ratio CS CLM % by weight of CL M in 1 polymer (Al) % by weight of CL M in 1 polymer (Bl) % by weight of CL M in 1 polymer composition (PCI) Tg of the Al core [°C] Tg of the Bl envelope [°C] Comparative example 1 90 / 10 - 0 0 0 Example 1 90 / 10 CLA 11 0 10 -39 105 Example 2 90 / 10 CLA 7.4 0 6.6 Example 3 90 / 10 CLA 18.5 0 16.7 -39 97 Example 4 95 / 5 CLA 11 0 11 -36 Example 5 90 / 10 CLMA 11 0 10 -37 91 Comparative example 2 90 / 10 CLA 0 30 3 -39 45 Comparative example 3 90 / 10 CLA 0 30 2 -39 63 Comparative example 4 90 / 10 CLA 0 30 2 -37 73

[0314]

[0315] [Table 2]

[0316] Table 2 - Powder properties Ease of use of powder reference comparative example 1 +++ example 1 +++ example 2 +++ example 3 +++ example 4 +++ example 5 +++ comparative example 2 ___ comparative example 3 — comparative example 4 -

[0317] The compositions according to the invention exhibit improved suitability for use in powder form. "Suitability for use in powder form" means the following:

[0318] +++ free-flowing powder

[0319] — heavy clumping which degrades the fluidity of the powder

[0320] - some clumping during the powder particle drying stage......

[0321] The compositions are mixed with PET and Charpy impact resistance ISO notching is evaluated. The results are presented in Table 3.

[0322]

[0323] [Table 3]

[0324] Table 3 - Impact resistance properties Impact resistance Char Impact resistance Char py (kJ / m²) at 10% in PET py (kJ / m²) at 15% in PET Initial reference after 1 week at 50°C and 50% humidity Initial after 1 week at 50°C and 50% humidity Comparative example 1 7.1 Example 1 14.9 11 16.9 14.2 Example 2 14.1 9.3 Example 3 15.6 12.1 17.9 14.2 Example 4 Example 5 Comparative example 2 13.7 10.1 15.6 12.8 Comparative example 3 14.7 10.7 Comparative example 4 14.2 10.1

[0325] The composition according to the invention and obtained according to the process of the invention leads to a significant increase in impact resistance.

Claims

Demands

1. Polymer composition (PCI) comprising: a) a polymer (Al) having a glass transition temperature below 10 °C, b) a polymer (Bl) having a glass transition temperature of at least 60 °C, said polymer (Bl) representing at least 2 wt% and at most 30 wt% of the composition based on a) and b) only, component a) and component b) of the composition (PCI) being part of a multi-step polymer (MPI), characterized in that the polymer (Al) comprises between 1 wt% and up to 100 wt% of polymerized monomeric unit (CLM) of general formula CH2=CR1COO(CH2)m(OCO(CH2)nl)n2 OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10.

2. Polymer composition (PCI) according to claim 1, characterized in that the polymer composition (PCI) comprises a multi-step polymer (MPI) comprising at least a) a step (A) comprising the polymer (Al) having a glass transition temperature below 10 °C, and at least b) a step (B) comprising the polymer (Bl) having a glass transition temperature above 60 °C.

3. Polymer composition (PCI) according to claim 1 or 2, characterized in that the polymer composition (PCI) is in the form of a polymer powder.

4. Polymer composition (PCI) according to any one of claims 1 to 3, characterized in that the polymer (Al) comprises between 2% by weight and 70% by weight of polymerized monomeric motif (CLM) and more preferably between 3% by weight and 50% by weight.

5. Polymer composition (PCI) according to any one of claims 1 to 3, characterized in that the polymer (Al) comprises from 5 wt% to 25 wt% of polymerized monomeric motif (CLM).

6. Polymer composition (PCI) according to any one of claims 1 to 5, characterized in that the polymer (Al) is a copolymer comprising butyl acrylate and a monomeric motif (CLM).

7. Polymer composition (PCI) according to any one of claims 1 to 6, characterized in that the polymerized monomeric motif (CLM) has the formula (1) [Formula 1] in which Ri is H or CH3 and n2 is from 1 to 5.

8. A method for manufacturing a polymer composition (PCI) according to any one of claims 1 to 8, comprising a multi-step polymer comprising the steps of a) emulsion polymerization of a monomer or a mixture of monomers (Am) to obtain in this step a layer (A) comprising the polymer (Al) having a glass transition temperature below 10 °C, b) emulsion polymerization of a monomer or a mixture of monomers (Bm) to obtain a layer in a step (B) comprising a polymer (Bl) having a glass transition temperature of at least 60 °C, characterized in that said mixture of monomers (Am) comprises a monomeric motif (CLM) of general formula CH2=CRiCOO(CH2)m(OCO(CH2)ni)n2OH, Ri being H or CH3, m being an integer from 1 to 5, ni being an integer from 1 to 10 and n2 being an integer from 1 to 10.

9. A process according to claim 8, characterized in that the process includes the additional step c) of multi-step polymer agglomeration.

10. A process according to claim 8 or 9, characterized in that the process includes the additional step d) of drying the polymer composition.

11. Use of the polymer composition (PCI) according to any one of claims 1 to 7 or obtained by the process according to any one of claims 8 to 10 as an impact resistance modifier.

12. Use according to claim 11 for a thermoplastic polymer (TPI).

13. Use of the polymer composition (PCI) according to claim 12, characterized in that the thermoplastic polymer (TPI) is selected from poly(vinyl chloride) (PVC), chlorinated poly(vinyl chloride) (C-PVC), polyesters such as, for example, poly(ethylene terephthalate) (PET) or poly(butylene terephthalate) (PBT), polyhydroxyalkanoates (PHA) or poly(lactic acid) (PLA), cellulose acetate, polycarbonates (PC), poly(methyl methacrylate) (PMMA), (meth)acrylic copolymers, thermoplastic poly(methyl methacrylate-ethyl coacrylates), poly(alkylene terephthalates), poly(vinylidene fluoride), poly(vinylidene chloride), polyoxymethylene (POM), polyamides semi-crystalline, amorphous polyamides, semi-crystalline copolyamides, amorphous copolyamides, polyetheramides, polyesteramides, styrene and acrylonitrile copolymers (SAN),and their respective mixtures or alloys.

14. Use according to claim 12, characterized in that said thermoplastic polymer (TPI) is a polyester or a mixture comprising a polyester.

15. Thermoplastic polymer composition (PC2) comprising the polymer composition (PCI) according to any one of claims 1 to 7 or obtained by the process according to any one of claims 8 to 10.

16. Thermoplastic polymer composition (PC2) comprising a thermoplastic polymer (TPI), preferably selected from a polyester.

17. Use of the polymer composition (PC2) according to claim 15 or 16 in the field of compositions for food, packaging, electrical and electronic, automotive, textile, 3D printing or toy applications.

18. Article comprising the polymer composition (PCI) according to any one of claims 1 to 7 or the polymer composition (PC2) according to claim 15 or 16.

19. Article according to claim 18, which is a bottle, a container, a 3D printed object, a film, a fiber or a textile fiber.