Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2/00—Processes of polymerisation
  • C08F2/12—Polymerisation in non-solvents
  • C08F2/16—Aqueous medium
  • C08F2/22—Emulsion polymerisation
  • C08F2/24—Emulsion polymerisation with the aid of emulsifying agents
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/26—Esters containing oxygen in addition to the carboxy oxygen
  • C08F220/32—Esters containing oxygen in addition to the carboxy oxygen containing epoxy radicals
  • C08F220/325—Esters containing oxygen in addition to the carboxy oxygen containing epoxy radicals containing glycidyl radical, e.g. glycidyl (meth)acrylate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F255/00—Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00
  • C08F255/02—Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00 on to polymers of olefins having two or three carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F257/00—Macromolecular compounds obtained by polymerising monomers on to polymers of aromatic monomers as defined in group C08F12/00
  • C08F257/02—Macromolecular compounds obtained by polymerising monomers on to polymers of aromatic monomers as defined in group C08F12/00 on to polymers of styrene or alkyl-substituted styrenes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F263/00—Macromolecular compounds obtained by polymerising monomers on to polymers of esters of unsaturated alcohols with saturated acids as defined in group C08F18/00
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F263/00—Macromolecular compounds obtained by polymerising monomers on to polymers of esters of unsaturated alcohols with saturated acids as defined in group C08F18/00
  • C08F263/02—Macromolecular compounds obtained by polymerising monomers on to polymers of esters of unsaturated alcohols with saturated acids as defined in group C08F18/00 on to polymers of vinyl esters with monocarboxylic acids
  • C08F263/04—Macromolecular compounds obtained by polymerising monomers on to polymers of esters of unsaturated alcohols with saturated acids as defined in group C08F18/00 on to polymers of vinyl esters with monocarboxylic acids on to polymers of vinyl acetate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F265/00—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00
  • C08F265/04—Macromolecular compounds obtained by polymerising monomers on to polymers of unsaturated monocarboxylic acids or derivatives thereof as defined in group C08F20/00 on to polymers of esters
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F291/00—Macromolecular compounds obtained by polymerising monomers on to macromolecular compounds according to more than one of the groups C08F251/00 - C08F289/00
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
  • C09D133/04—Homopolymers or copolymers of esters
  • C09D133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
  • C09D133/062—Copolymers with monomers not covered by C09D133/06
  • C09D133/068—Copolymers with monomers not covered by C09D133/06 containing glycidyl groups

Definitions

• the present invention relates to a process for preparing a copolymer grafted with polyunsaturated fatty acids in aqueous phase.
• the invention also relates to a copolymer grafted with polyunsaturated fatty acids obtainable by this process and its uses as binder in coating compositions and in particular in decorative or industrial paint compositions, in adhesive compositions or in in mineral binder compositions.
• Binders for alkyd-based paints fulfill this dual requirement.
• these alkyd binders have the disadvantage of having low chemical resistance to solvents such as methyl ethyl ketone or aromatics such as xylene and vis-à-vis acids and they are sensitive to UV. It therefore appears advantageous to improve the durability of the coating compositions to combine acrylic polymers that are more resistant to solvents such as methyl ethyl ketone or aromatics such as xylene and to acids such as acid. acetic and more stable vis-à-vis the UV binders alkyd type.
• the polymerization is then carried out by a mini-emulsion technique.
• the available double bonds of the alkyd resin are present in the polyunsaturated fatty acid type parts of the alkyd resin.
• These polyunsaturated fatty acid-type parts represent only about 15% by weight of the alkyd resin, for alkyd resins whose oil length is such that they have a dust-free time and a tack-free time required for applications in decorative painting.
• the addition of the acrylic monomers therefore has the effect of diluting the fraction of polyunsaturated fatty acids, which leads to poorer performance of the graft copolymer obtained when it is used as a binder in coating compositions. Especially when using this graft copolymer as a binder in a paint it is sensitive to solvents, it is not scratch resistant and the mechanical properties are degraded.
• this process requires the realization of 2 steps before starting the polymerization: one in the solvent phase and one in the aqueous phase. Due to the solvent phase stage, there is necessarily residual solvent at the end of the process which presents ecological problems.
• part of the copolymer obtained by this process remains sensitive to water.
• the fatty acid groups are in a hydrophilic environment because they are associated with methacrylic acid.
• the soluble alkali compound is located on the surface of the graft copolymer particles. After drying, this interstitial zone rich in acid promotes the penetration of water into the film.
• graft copolymer when used as a binder in coating compositions and in particular in decorative or industrial paint compositions, or in adhesive or inorganic binder compositions such as a mortar.
• One of the aims of the invention is also to prepare a graft copolymer which, when used as a binder in coating compositions, has good water and solvent resistance properties, good mechanical strength of the coating and in particular vis-à-vis scratches, and therefore generally a higher durability.
• Another object of the invention is also to prepare a graft copolymer which is present when it is used as a binder in adhesive or inorganic binder compositions such as a mortar with good water and solvent resistance properties. a good mechanical strength of the adhesive or inorganic binder composition with respect to the stresses, and therefore generally a higher durability.
• a modified monomer (A) is prepared by reacting at least one glycidyl ester of acrylic acid or methacrylic acid with at least one drying or drying oil fatty acid, 2) this modified monomer is dissolved ( A) obtained in the first step in at least one monoethylenically unsaturated monomer (B),
• step 3 the modified monomer solution (A) / monoethylenically unsaturated monomer (B) obtained in step 2 is then pre-emulsified by adding a surfactant and water with stirring, so that an emulsion is obtained; with a continuous water phase, that is to say an oil-in-water emulsion,
• step 3 the emulsion obtained in step 3 is subjected to high shear in order to obtain a stable mini-emulsion having droplets with a mean diameter of between 10 nm and 1000 nm,
• step 4 the miniemulsion obtained in step 4 is polymerized by addition of an initiator.
• the subject of the invention is also the graft copolymer obtainable by the above process.
• the invention also relates to the use of this graft copolymer as a binder in coating compositions, in particular decorative or industrial paint compositions.
• a modified monomer (A) is prepared by reacting at least one glycidyl ester of acrylic acid or methacrylic acid with at least one drying or drying oil fatty acid.
• fatty acids examples include safflower oil fatty acid, linseed oil fatty acid, soybean oil fatty acid, sesame oil fatty acid, lactic acid oil, poppy oil fatty acid, perilla oil fatty acid, goat oil fatty acid, grape seed oil fatty acid, corn oil fatty acid , tall oil fatty acid, sunflower oil fatty acid, cottonseed oil fatty acid, whale oil fatty acid, oil oil fatty acid Hevea, sugarcane oil fatty acid, etc.
• the fatty acid of safflower oil, the fatty acid of linseed oil, the acid are particularly preferred.
• conjugated double bond fatty acids are Canton oil fatty acid, oiticica oil fatty acid, dehydrated castor oil fatty acid, and dicarboxylic acid fatty acid. Hidiene (trade name of conjugated double bond fatty acid, produced by Soken Kagaku Co, Ltd in Japan). The amount of conjugated double bond fatty acid is less than 30% by weight, based on the total fatty acid.
• the other component of the modified monomer (A), glycidyl acrylate or glycidyl methacrylate can be used as the glycidile ester. It is also possible to carry out an esterification reaction between the polyunsaturated fatty acid and a hydroxyalkyl (meth) acrylate. Preferably glycidyl acrylate or glycidyl methacrylate is used as the glycidyl ester.
• the modified monomer (A) is usually prepared by reacting the two above components, ie the polyunsaturated fatty acid and the glycidyl acrylate or the glycidyl methacrylate at a temperature of between 40 ° C.
• reaction catalyst such as tetraethylammonium bromide, although these conditions vary with the type of fatty acid used.
• a polymerization inhibitor such as hydroquinone, p-benzoquinone or hydroquinone methylether (MEHQ).
• the modified monomer (A) obtained in the first step is dissolved in at least one monoethylenically unsaturated monomer (B).
• the monoethylenically unsaturated monomer (B) may be chosen from the monomers usually used for the synthesis of latex. The monomers are chosen such that the graft copolymer obtained has a glass transition temperature (TG) of between -40 ° C. and + 100 ° C.
• the monoethylenically unsaturated monomer (B) may be chosen from:
• alkyl acrylates and methacrylates in which the alkyl group contains from 1 to 10 carbon atoms, for example the methyl, ethyl, n-butyl and 2-ethylhexyl acrylates and methacrylates;
• vinylaromatic monomers in particular styrene.
• These monomers can be used alone or in mixtures with other ethylenically unsaturated monomers with which they are copolymerizable. Mention may in particular be made of mixtures of vinylaromatic monomers and in particular styrene and of alkyl acrylates or methacrylates in which the alkyl group contains from 1 to 10 carbon atoms, for example the methyl, ethyl and n-butyl acrylates and methacrylates. 2-ethylhexyl.
• ethylene and olefins such as isobutene
• vinylaromatic monomers such as methylstyrenes, vinyltoluenes
• vinyl halides such as chloride of vinyl, vinylidene chloride, diolefins especially butadiene; the (meth)
• phosphate monomers which make it possible to obtain good adhesion on metal surfaces, such as vinylphosphonic acid, 2- (methacryloyloxy) ethylphosphonic acid (RN 80730-17-2), or acid 2 -
• the monoethylenically unsaturated monomer (B) may further comprise functional monomers capable of providing good properties of resistance to water and solvents, or to give the latex specific adhesion properties.
• 1-methacrylamido, 2-imidazolidinone ethane sold under the trade name Sipomer WAM II by the company Rhodia glycidyl methacrylate, vinyltriethoxysilane or vinyl monomers bearing cyclodextrin groups.
• Sipomer WAM II glycidyl methacrylate, vinyltriethoxysilane or vinyl monomers bearing cyclodextrin groups.
• 1-methacrylamido, 2-imidazolidinone ethane sold under the trade name Sipomer WAM II by the company Rhodia makes it possible to improve the adhesion of the latex composition to supports having carbonyl groups, for example supports made from polyesters, or layers of old alkyd type paintings.
• Vinyltriethoxysilane makes it possible to improve the adhesion of the latex composition to glass or other mineral substrates of the metal oxide type.
• the glycidyl methacrylate provides the possibility of crosslinking after application of the paint film through the presence of epoxy groups.
• the monomers copolymerizable with vinyl acetate and / or acrylic esters and / or styrene are generally used in proportions such that the glass transition temperature (TG) of the graft copolymer obtained is between -50 ° C. and + 110 ° C. 0 C.
• the monomers copolymerizable with vinyl acetate and / or acrylic esters and / or styrene are used in proportions such that the glass transition temperature (TG) of the graft copolymer obtained is between -40 ° C. and + 6O 0 C.
• the proportions of monomers (A) which are dissolved in at least one monoethylenically unsaturated monomer (B) are such that the amount of (A) is between 10 and 80% by weight of modified monomer (A) relative to the total weight of monomers (A) + (B).
• the amount of (A) is between 10 and 50% by weight of modified monomer (A) relative to the total weight of monomers (A) + (B).
• the modified monomer solution (A) / monoethylenically unsaturated monomer (B) obtained in step 2 is then pre-emulsified by adding a surfactant and stirring water. such that an emulsion with a continuous water phase is obtained, that is to say an oil-in-water emulsion.
• the organic phase which is the dispersed phase comprises the monomers (A) and (B). It is generally from 10% to 50% by weight relative to the total weight of the emulsion.
• the amount of (A) in the organic phase of the emulsion is between 10 and 80% by weight of modified monomer (A) relative to the total weight of monomers (A) + (B).
• the amount of (A) in the organic phase of the emulsion is between 10 and 50% by weight of modified monomer (A) relative to the total weight of monomers (A) + (B).
• the stirring is carried out in such a way that the dispersed phase is in the form of droplets having a mean diameter of between 1 to 100 microns.
• the average diameter of the droplets is between 10 and 50 microns.
• the surfactant which is used in this third step may be any surfactant conventionally used for emulsion polymerization processes.
• the surfactants that can be used are anionic, cationic or nonionic emulsifiers. A surfactant alone or a mixture of several surfactants can be used.
• alkyl sulphates such as sodium lauryl sulphate, alkyl sulphonates, alkyl aryl sulphates, alkyl aryl sulphonates such as sodium dodecyl benzene sulphonate, aryl sulphates, aryl sulphonates and alkyl ethoxylates, are generally used.
• anionic surfactants are generally employed in a proportion of 0.01 to 5% by weight relative to the total weight of the monomers.
• the use of one of the anionic surfactants mentioned above can also be coupled with a water-soluble non-ionic polymer such as polyvinyl alcohol or polyvinylpyrrolidone (PVP).
• a water-soluble non-ionic polymer such as polyvinyl alcohol or polyvinylpyrrolidone (PVP).
• anionic surfactants mentioned above can also be coupled with a stabilizing system based on synthetic anionic polymers, for example poly (meth) acrylic acid, poly (meth) acrylamide, polyvinylsulfonic acids, and water-soluble copolymers thereof, or condensates such as melamine formaldehyde sulfonates, naphthalene formaldehyde sulfonates, styrene / maleic acid copolymers, and maleic acid vinyl ether copolymers.
• synthetic anionic polymers for example poly (meth) acrylic acid, poly (meth) acrylamide, polyvinylsulfonic acids, and water-soluble copolymers thereof, or condensates such as melamine formaldehyde sulfonates, naphthalene formaldehyde sulfonates, styrene / maleic acid copolymers, and maleic acid vinyl ether copolymers.
• the emulsion obtained in step 3 is subjected to high shear in order to obtain a stable mini-emulsion having droplets with a mean diameter of between 10 nm and 1000 nm.
• Suitable for obtaining a high shear suitable for the present invention is for example an ultrasound probe, a colloid mill or a homogenizer.
• an ultrasound probe mention may be made, for example, of the Vibracell Sonificator 600 W marketed by Bioblock Scientific.
• a stable mini-emulsion is obtained having droplets with a mean diameter of between 10 nm and 1000 nm.
• the average diameter of the droplets is between 80 nm and 300 nm.
• the miniemulsion obtained in step 4 is polymerized by addition of an initiator.
• an initiator It is a radical polymerization, so it can be initiated by a free radical initiator.
• Suitable free radical initiators are known to those skilled in the art. Any system generating free radicals that is effective at the polymerization temperature can be used. It is possible to use a water-soluble or oil-soluble polymerization initiator.
• Systems generating free radicals include, for example: organic peroxides, such as benzoyl peroxide, lauroyl peroxide and dicumyl peroxide, inorganic persulfates such as sodium persulfate, potassium persulfate, ammonium persulfate, Pazobis (isobutyronitrile) (AIBN), - redox pairs such as Fe 24 VH 2 O 2 , ROH / Ce 4+ (where R represents an organic group such as a C 1 -C 6 alkyl group, or C 5 aryl); C8) or K 2 S 2 O 8 / Fe 2+ . It is employed in an amount of between 0.05 and 2% by weight relative to the total of the monomers.
• organic peroxides such as benzoyl peroxide, lauroyl peroxide and dicumyl peroxide
• inorganic persulfates such as sodium persulfate, potassium persulfate, ammonium persulfate, Pazo
• the reaction temperature is generally between 0 and 100 ° C., and preferably between 30 and 90 ° C.
• the preferred polymerization temperature depends on the choice of initiator.
• the size of the graft copolymer particles which is formed in the emulsion is between 60 nm and 300 nm, that is to say a size of the same order of magnitude as the average diameter of the monomer droplets of the mini-emulsion of the stage. 4.
• the polymerization is carried out in a reactor in which water, a surfactant chosen from the list of surfactants used for the production of the emulsion in step 3 of the preparation process, is firstly added. above, and an initiator.
• This mixture is heated to the polymerization temperature, and the miniemulsion prepared in step 4 is added continuously so as to better control the exothermicity of the polymerization.
• a transfer agent in proportions ranging from 0 to 3% by weight relative to the monomer (s), generally chosen from mercaptans such as N-dodecylmercaptan or tert-dodecylmercaptan, cyclohexene, halogenated hydrocarbons such as chloroform, bromoform, carbon tetrachloride. It adjusts the length of the molecular chains. It is added to the reaction medium either before the polymerization or during polymerization.
• the subject of the invention is also the graft copolymer obtainable by the process described above.
• the aqueous graft copolymer dispersion can be used as is, or can be dried to obtain a powder.
• powder coatings can be described as "solid paints” that can be melted to form a continuous film on the substrate (often metal, but wood, some substitute wood, ceramics, glass and some plastics can also be painted).
• the powders may be "thermoplastic” or “thermosetting”.
• thermosetting powders crosslink and polymerize with heat, while thermoplastic powders remain heat sensitive. It is for this reason that the term "powder coatings" used in industry generally refers to thermosetting powder coatings. These paints are easily sprayed electrostatically or tribostatically onto the substrate: as the thickness increases, the paint "self-polishes” to produce a relatively homogeneous film thickness. The object painted with the powder is then dried in the oven. The powder melts and forms a continuous film, before chemically reacting and becoming a solid and inert coating. They have a number of advantages over traditional liquid paints, especially with regard to the environment since they are 100% solid, they contain virtually no volatile organic compounds. Emissions to the environment are negligible. The process of manufacture of powder paints and their mode of application is described in the following paragraphs:
• the pre-mix is then passed through an extruder comprising a heated tube in which (generally) two screws pivot.
• the mixture of heat and friction caused by the shearing of the screws, melts the resin and thoroughly mixes all the other ingredients (mainly pigments and fillers), dispersing them in the molten resin.
• the ingredients stay only about 15 seconds in the extrusion zone. It is therefore essential to have a homogeneous premix to obtain a homogeneous powder paint.
• the mixture leaves the extruder in the form of a hot liquid (c 130 0 C) extremely viscous. Since the resin is thermosetting, it is imperative to cool the mixture as fast as possible to avoid any hardening reaction.
• the product extruded passes immediately into a system of water-cooled nip rollers that flatten it until a thin strip (about 2mm thick and 1m wide) of wide surface is obtained.
• the ribbon is still a little warm at this time (about 70-80 0 C), but its temperature is reduced to room temperature during its passage on a metal conveyor also cooled by water.
• the tape At the end of the conveyor, the tape is at room temperature and brittle, ready to be granulated in storage containers
• the granulated "chip” is then conveyed to a mill.
• the latter has a rotor with pins pivoting at about 6000 rpm inside a chamber with serrated walls. The chips are thrown violently against the pins, the wall and the other chips until they are transformed into a fine powder.
• the subject of the invention is also the graft copolymer powder that can be obtained by the powder-paint preparation process.
• the graft copolymer as a binder in a mineral binder composition such as a mortar, it is possible to use the drying processes usually used to produce polymer powders. redispersible.
• the redispersible powder is preferably prepared by spray drying the aqueous graft copolymer dispersion optionally under nitrogen to prevent oxidation of the double bonds of the graft copolymer. This drying is carried out in conventional spray drying systems, using atomization by means of single, double or multiple liquid nozzles or a rotating disk.
• the discharge temperature selected is generally in the range of 50 to 100 ° C, preferably 60 to 90 ° C, depending on the system, the glass transition temperature of the graft copolymer, and the desired degree of drying.
• an anti-caking agent into the spray column together with the aqueous graft copolymer dispersion. which results in a preferable deposition of the anti-caking agent on the particles of the dispersion.
• the preferred anti-caking agents are aluminum silicates, calcium or magnesium carbonates, or mixtures thereof, silicas, hydrated alumina, bentonite, talc, or mixtures of dolomite. and talc, or calcite and talc, kaolin, barium sulfate, titanium oxide, or calcium sulfoaluminate (satin white).
• the particle size of the anti-caking agents is preferably in the range of 0.001 to 0.5 mm. It is also possible to introduce, before drying, a conventional redispersion agent such as, for example, polyvinyl alcohol, N-vinylpyrrolidone, formaldehyde / naphthalenesulfonic acid condensates, formaldehyde / phenylsulfonic acid condensates, or homopolymers of 2-acrylamido acid. 2-methylpropanesulfonic acid.
• the invention also relates to the redispersible graft copolymer powder obtainable by the method described above.
• the pulverulent compositions according to the invention are completely redispersible in water at ambient temperature by simple stirring.
• totally redispersible is meant a pulverulent composition according to the invention which, after addition of a suitable amount of water, makes it possible to obtain a reconstituted graft copolymer whose particle size of the particles is substantially identical to the particle size of the copolymer particles.
• grafted present in the starting emulsion before drying Following this redispersion, the particle size of the reconstituted graft copolymer obtained is measured by laser granulometry. The more the particle size of the reconstituted graft copolymer is close to that of the graft copolymer used in the synthesis of the pulverulent composition, the better is the redispersibility.
• the invention also relates to the reconstituted graft copolymer obtained by redispersion in water of a powdery composition as defined above.
• the invention relates to the use of the graft copolymers of the invention as a binder in coating compositions, and in particular in decorative or industrial paint compositions, or as a binder in adhesive compositions, or even as a binder in inorganic binder compositions such as mortars.
• the graft copolymer binder compositions of the invention have improved solvent and mechanical strength. If it is binders used in coating compositions, this better resistance to solvents and better mechanical strength will increase their life or the duration of their presence on the substrate they protect. Their resistance to aging can also be increased. Their resistance to dimensional variations of the support can also be increased.
• the term "paint” is used in the broad sense to denote any coating of polymeric nature deposited on a substrate and may have a particular protective function thereof, and more particularly to designate the actual aqueous paints, varnishes and stains.
• stain and “varnish” have the usual meaning in the technical field concerned here. It will be specified for the glaze that it is generally a formulation or transparent or semi-transparent composition applied to the wood or on the substrate and intended to protect it and whose solids content may be of the order of 10. % by weight or of the order of 40 to 50% by weight depending on whether it is a primary or finishing varnish. For the varnish it is a formulation or composition more concentrated than the stain.
• the invention is generally applicable to any type of aqueous paints, especially any type of stain or varnish, used on any substrate.
• This substrate may be in particular wood or metals, or a mineral substrate not covered with paint or a substrate covered with a primer or an old paint layer to be renovated.
• the invention can be applied to automotive paints.
• the amount of graft copolymer present in a coating composition is between 10 to 95% by volume fraction.
• the amount of graft copolymer present in a coating composition is between 20 to 85% by volume fraction.
• the amount of graft copolymer present in a mineral binder composition is between 0.5 to 30% by mass fraction.
• the amount of graft copolymer present in a mineral binder composition is between 1 and 10% by mass fraction.
• inorganic binder is meant aerial binders or hydraulic binders. Among the aerial binders may be mentioned plasters.
• hydraulic binders include cements that can be Portiand type, aluminous or blast furnaces, fly ash, calcined schists or pozzolans.
• the hydraulic binders are cements.
• the inorganic binders have the property of crystallizing in the presence of water, and thus of "setting". They make with water a gradually hardening paste, even in the absence of air and especially under water. Mixed with sand and gravel, and depending on their nature, they can make concrete, mortars, or serious road.
• the amount of graft copolymer present in an adhesive composition is 70 to 100% by volume fraction.
• the amount of graft copolymer present in an adhesive composition is from 80 to 100% by volume fraction.
• the invention also applies to varnishes used in cosmetics.
• the graft copolymers of the invention in compositions comprising a drying agent. This is the case for coating compositions or adhesive compositions.
• the siccative agent is a catalyst promoting the oxidation of double bonds corresponding to unsaturations of the fatty acid.
• the use of a drying agent makes it possible to accelerate the crosslinking of the binder and to reach a good level of mechanical strength and solvent resistance more quickly.
• the graft copolymer according to the invention makes it possible to achieve good mechanical characteristics and solvent resistance without addition of siccative agent.
• This implementation can be interesting in the case where the user wants to get rid of the presence of heavy metals (cobalt salts for example) to meet requirements of respect for the environment.
• the drying of the coating composition, paint or varnish, comprising the graft copolymer of the invention after its application on a support can be carried out at room temperature. This drying can also be carried out at high temperature if the application conditions allow it, that is to say between 30 ° C. and 300 ° C., and preferably between 30 ° C. and 100 ° C., which has the advantage consequence of further increasing the level of crosslinking.
• Example 1 According to the Invention - Synthesis of a Methacrylate Hybrid of a Polyunsaturated / Acrylic Fatty Acid (03BBT021) a) Synthesis of a Polyunsaturated Fatty Acid Methacrylate
• the polyunsaturated fatty acid methacrylate of step a) is dissolved in a mixture of styrene (302 g), butyl acrylate (226 g) and acrylic acid (8 g).
• This solution is dispersed in an aqueous solution of water (377 g), sodium lauryl sulphate (8 g, SLS surfactant), Disponil FES 32 IS (2.44 g, ethoxylated surfactant marketed by Cognis), Sipomer WAM II (11 g marketed by Rhodia) and sodium persulfate (1.5 g).
• the dispersion is homogenized using an Ultra-Turrax homogenizer (Janke &
• the pre-emulsion obtained is subjected to high shear (ultrasound, Vibracell
• a polymerization reactor equipped with a stirring blade (anchor) and refrigerant is thermostated at 80 0 C.
• the temperature is maintained at 80 ° C. for one hour.
• the latex obtained is cooled and diluted with water. This latex has the following characteristics: dry extract, 43.5%, pH 1.8, average diameter 170 nm.
• a mixture of alkyd resin emulsion and styrene-acrylic latex made to have the same mass proportions of alkyd and latex as the two hybrid binders of the invention.
• the chemical composition of the alkyd and latex emulsion is comparable to the chemical composition of the binders of the invention. Comparative Example 4 (03BBT024)
• Step b) of Example 1 according to the invention was carried out but substituting the methacrylate of the fatty acid prepared in step a) of Example 1 with a Z 474 alkyd resin marketed by DSM Resins.
• the ratio of alkyd resin to acrylic copolymer is 40% to 60% by weight. At this ratio, the final product always contains 15% of fatty acid, which represents for comparison an acid content identical to that of Example 1 according to the invention as well as a ratio of acrylic monomers and styrene identical to that of Example 1 according to the invention.
• This test involves subjecting the paint or varnish film to repeated rubbing with a cotton wool soaked in methyl ethyl ketone (MEK) and examine the part tested.
• MEK methyl ethyl ketone
• PANEL PANEL. It also uses hydrophilic cotton and methyl ethyl ketone (no special specification).
• the support is a binder film applied at 150 microns wet on a metal plate.
• the cotton is imbibed with methyl ethyl ketone.
• Methyl ethyl ketone is put back on the cotton if it seems dry and we start again.
• a "double rub” is a round-trip friction performed on the plate.
• the binder film is subjected to contact with a drop of chemical for a period of 30 minutes. After this exposure, the condition of the film is evaluated. It is recommended to place a reference product among those tested in order to use this test as a comparative method.
• the binder to be tested is applied at 150 microns wet on a chromated aluminum type metal plate (ref AL36 at supplier Q-PANEL)
• the following chemical agents are used:
• ammonia at approximately 20% (by weight), ethanol 96 °,
• a drop of the reagent is deposited on the binder.
• the set is covered with a watch glass or a plastic stopper. After 30 minutes, the reagent is removed from the film by wiping with a paper towel. 4. expressions of results
• the state of the binder film is evaluated by giving a score of 0 to 5 according to the following rating: 0: The film is not attacked, the reagent leaves no trace.
• the test consists in measuring the damping time of a pendulum resting, by means of two steel balls, on the sheet to be studied.
• the specimen is fixed on the platform.
• the horizontality of the device is checked using the spirit level.
• the stopwatch is stopped when the amplitude reaches 4 °. In the case of devices with an automatic counting system, these operations are carried out automatically, but the type of device must be taken into account. To avoid a parallax error, the experimenter's eye should be placed so that he can see his own image behind the 0 ° graduation. 4. Expression of results
• the hardness result is the number of seconds obtained by calculating the average of 2 successive determinations made in 2 different places of the same test piece. IV- Measurement of elonqation on free composite 1. Principle
• the test consists in stretching test specimens of standardized dimensions to break to a tensile testing machine capable of ensuring a constant speed of movement of the jaw or moving roller.
• a traction machine is used:
• dumbbells are dumbbells
• test pieces used for this type of test are cut from a H3 type punch, with a total length of 50 mm.
• the thicknesses are generally between 0.5 and 1 mm.
• the film to be cut with or without silicone paper is placed on a flat surface plate, the material of which is sufficiently flexible so as not to damage the punch.
• the cutting of the specimens is carried out at one time using the appropriate equipment.
• Each test specimen is examined and rejects those which have defects or primers of rupture visible to the naked eye.
• the thickness is measured at three different points distributed over the central part of the test piece.
• the width of the specimen is considered to be that of the width between cutting edges of the central part of the punch. 5. operating mode
• test pieces The test is carried out under normal conditions of temperature and humidity, 23 ° C ⁇ 2 ° C, 55% ⁇ 5% relative humidity.
• the specimen is placed while avoiding as much contact with the central part, in the fastening device whose initial spacing is known and pre-set.
• the machine is started at a speed of 50 mm / min until the test piece breaks.
• the test consists of measuring the minimum load required for the appearance of a regular scratch on a rotating test piece.
• An arm with a weight makes it possible to vary the load applied to the scratch tool (a diamond point) on the sheet to be studied.
• the Taber Scratch Resistance Meter is referenced as Model 203.
• the measurements are made on binders applied to glass plates to a thickness of 150 microns wet.
• the specimens are allowed to stand for at least 12 hours in a room where the temperature is (23 ⁇ 3 ° C) and the relative humidity is (55 ⁇ 10%).
• the specimen is attached to the platform for rotating the specimen.
• the horizontality of the device is checked using the spirit level.
• the oscillating arm equipped with a diamond point is applied to the film of varnish, the weight being adjusted so as to have the lowest pressure.
• the specimen is rotated.
• the scratch resistance result is the minimum gram pressure for the appearance of a continuous and regular streak obtained by calculating the average of 2 successive determinations carried out at 2 different places of the same test piece.
• This example relates to the evaluation of the two binders of the invention dried in pure form at 23 ° C. and 55% relative humidity for one month.
• Table 1 summarizes the products tested and their comparative
• the copolymer according to the invention has improved mechanical characteristics which are characterized by: a greater hardness; an increase in the maximum stress while maintaining a significant level of deformation; - greater resistance to scratching.
• Table 6 summarizes Taber scratch resistance results. We note the pressure in grams necessary for the formation of a scratch. Table 6
• This example concerns the evaluation of the binder of Example 1 of the invention dried so as to form a pure binder film under optimum conditions in terms of crosslinking: a drying agent was therefore added and dried at high temperature. .
• Table No. 7 shows the test products examples according to the invention or comparative examples as well as the duration and the drying temperature for each of the products.
• Table 12 summarizes Taber scratch resistance results. We note the pressure in grams necessary for the formation of a scratch. Table 12
• the graft copolymer of Example 1 of the invention has mechanical characteristics further improved by further crosslinking (addition of driers) which are characterized by:

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• 2005
  • 2005-10-14 FR FR0510525A patent/FR2892122A1/fr not_active Withdrawn
• 2006
  • 2006-10-13 US US12/090,128 patent/US20090312494A1/en not_active Abandoned
  • 2006-10-13 WO PCT/FR2006/002309 patent/WO2007042684A1/fr active Application Filing
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